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Biomedical subjects

A Bach

Publications and source records attributed to A Bach.

At least 73 records · Page 4Linked to original sources

[Managed care. Its impact on health care in the USA, especially on anesthesia and intensive care].

Managed care, i.e., the integration of health insurance and delivery of care under the direction of one organization, is gaining importance in the USA health market. The initial effects consisted of a decrease in insurance premiums, a very attractive feature for employers. Managed care promises to contain expenditures for health care. Given the shrinking public resources in Germany, managed care seems attractive for the German health system, too. In this review the development of managed care, the principal elements, forms of organisation and practical tools are outlined. The regulation of the delivery of care by means of controlling and financial incentives threatens the autonomy of physicians: the physician must act as a "double agent", caring for the interest for the individual patient and being restricted by the contract with the managed care organisation. Cost containment by managed care was achieved by reducing the fees for physicians and hospitals (and partly by restricting care for patients). Only a fraction of this cost reduction was handed over to the enrollee or employer, and most of the money was returned with profit to the shareholders of the managed care organisations. The preeminent role of primary care physicians as gatekeepers of the health network led to a reduced demand for specialist services in general and for university hospitals and anesthesiologists in particular. The paradigm of managed care, i.e., to guide the patient and the care giver through the health care system in order to achieve cost-effective and high quality care, seems very attractive. The stress on cost minimization by any means in the daily practice of managed care makes it doubtful if managed care should be an option for the German health system, in particular because there are a number of restrictions on it in German law.

Anesthesia↗

Axotomy-induced c-JUN expression in young medial septal neurons is regulated by nerve growth factor.

In the present study we investigated the axotomy-induced expression of the proto-oncogene c-jun in young rat medial septal neurons and its regulation by nerve growth factor. First, medial septal neurons were retrogradely labelled by Fast Blue injection into the hippocampus at postnatal day 1 (P1). Rats of different developmental ages (P6, P9, P14, P21, P28 and P42) were then subjected to bilateral fimbria-fornix transection resulting in the axotomy of septohippocampal projection neurons. After the lesion, c-JUN immunoreactivity was observed in the nuclei of axotomized medial septal neurons of all stages examined, suggesting that c-JUN induction is an age-independent feature of axotomized medial septal neurons. Double immunolabelling for choline acetyltransferase and c-JUN or parvalbumin and c-JUN, respectively, revealed that both cholinergic and GABAergic septohippocampal projection neurons express c-JUN after axotomy. In addition, a co-localization of immunostaining for c-JUN and the neuropeptide galanin was found after lesion, as both proteins were induced in the same medial septal neurons following fimbria-fornix transection. Next, the regulation of c-JUN expression in axotomized medial septal neurons was studied in organotypic cultures of the medial septum. Axotomized medial septal neurons in culture did not express c-JUN in contrast to the in vivo situation. With the concept that nerve growth factor suppresses c-JUN expression, slice cultures of the medial septum were treated with antibodies against nerve growth factor. This treatment caused a dose-dependent increase in c-JUN-positive cells in these slice cultures. Simultaneous addition of nerve growth factor and antibodies against nerve growth factor resulted in the reversal of this effect. These data suggest an age-independent induction of c-JUN in axotomized medial septal neurons and its regulation by nerve growth factor.

Acetylcholine↗

Developmental expression patterns of mouse sFRP genes encoding members of the secreted frizzled related protein family.

Development of the metanephric kidney is an experimental model system to analyze interactions between mesenchymal and epithelial cells and mesenchymal-epithelial transition. To study the underlying genetic mechanisms we employed organ culture and differential display PCR to identify genes regulated upon induction of mesenchymal cells. One of the genes found encodes the secreted frizzled related protein 2 (sFRP2) that is upregulated within 2 days of in vitro development. In vivo sFRP2 expression was likewise found in mesenchymal condensates and subsequent epithelial structures. Detailed in situ hybridization analysis revealed sFRP2 expression during development of the eye, brain, neural tube, craniofacial mesenchyme, joints, testis, pancreas and below the epithelia of oesophagus, aorta and ureter where smooth muscles develop. In a comparative analysis transcripts of the related sFRP1 and sFRP4 genes were frequently found in the same tissues as sFRP2 with their expression domains overlapping in some instances, but mutually exclusive in others. While sFRP1 is specifically expressed in the embryonic metanephros, eye, brain, teeth, salivary gland and small intestine, there is only weak expression of sFRP4 except for the developing teeth, eye and salivary gland. The interpretation of the highly specific spatial and temporal expression patterns of sFRP genes will partly depend on a better functional understanding of the interaction between wnt, fz and sFRP family members. Nevertheless, sFRP genes must play quite distinct roles in the morphogenesis of several organ systems.

Animals↗

Catheter-related infections in long-term catheterized dogs. Observations on pathogenesis, diagnostic methods, and antibiotic lock technique.

BACKGROUND: Intravascular catheters are associated with severe infections in patients, but only few reports on this problem in animal research exist. OBJECTIVE: We report on catheter-related bacterial colonization and its consequences in long-term catheterized animals. MATERIAL AND METHOD: Foxhounds were instrumented with intravascular catheters and flow probes to study the regulation of renal blood flow and pressures. RESULTS: After flushing the catheters, alterations in renal blood flow were observed and these could be related to bacterial colonization of intravascular catheters with Pseudomonas species. After attention had been focused on aseptic technique in all experimental phases and prophylactic antibiotic lock instituted, the occurrence of Pseudomonas bacteremia ceased, and the magnitude and incidence of catheter-related colonization and infection by Pseudomonas species dropped considerably. CONCLUSION: The catheter-related colonization that occurred spontaneously in these animals resembled findings in animal experiments in which catheter-related infections were deliberately induced as well as observations made with regard to catheter-related infections in patients. This report emphasizes the importance of asepsis when working with animals with long-term intravascular catheters. We suggest that monitoring for this complication, e.g., by means of catheter cultures at the time of removal, should routinely be part of protocols for animal experiments using long-term intravascular catheters.

Animals↗

[Economic aspects of anesthesia. I. Health care reform in the German Republic].

Implications for Hospitals and Departments of Anaesthesiology. This article outlines the new German health care laws and their impact on the statutory health care system, hospitals and anaesthesia departments. The German health care system provides coverage for all citizens, although financial support from the public sector is on the downgrade. Hence, pressure to reduce public sector health care spending is likely to continue in the near future. Hospital costs account for one-third of total health care spending in Germany, and hospitals are facing increasing economic constraints: the volume and the charges for specific medical treatments are negotiated between the hospitals and the insurance agencies (or sickness funds) in advance. Only part of hospital care is still reimbursed on the basis of a per diem rate, and an increasing number of services are based on fixed payments per case or treatment. Reducing the costs for this treatment is therefore of utmost importance for hospitals and hospital departments. The prospective payment system and the pressure to contain costs demand a controlling system that allows for cost accounting per case. However, an economic evaluation must include comparative analysis of alternative therapeutic options in terms of both costs and outcome. Economic aspects challenge the traditional relationship between physicians and patients: doctors are still the advocates of their patients, but also act as agents for their institutions. Nevertheless, not only economic issues, but also ethical priorities and the value of an anaesthetic practice must be considered in the era of cost containment. Anaesthetists must be actively involved in providing high-quality care with its obvious benefits for the patient and be able to resist efforts to cut out expensive treatment modalities regardless of their benefits.

Anesthesia↗

[Economic aspects of anesthesia. II. Cost control in clinical anesthesia].

The primary scope of economic analyses is the quantification of the costs (input) in relation to the results (outcome, output). According to whether a similar or different dimension of outcome parameters is chosen, it is possible to differentiate between cost minimisation, cost effectiveness, cost benefit and cost utility analyses. Decision trees and sensitivity analyses serve to develop or examine cost outcome studies. The principal perspective of economic analysis is of crucial significance. In the present overview of cost control programmes in clinical anaesthesia, the perspective chosen throughout is that of budget responsibility in a department of anaesthesiology. With regard to economic factors in clinical anaesthesiology, the cost of medical and nursing staff represents the largest cost block. It is, therefore, essential that personnel is efficiently employed, i.e. how the perioperative procedure is organised. In the area of material costs, blood products--including coagulation factors and plasma substitutes--are particularly cost intensive, followed by medical products and drugs, especially muscle relaxants and inhalational anaesthetics. In the perioperative context, the costs of anaesthesia personnel account for 5-15% of the total costs of patient care, while material costs account for 2-10%. In view of this small portion of the total costs, cost control programmes in anaesthesia can only make a relatively small contribution to reducing overall cost. However, it must be realised that anaesthesia care is vitally important for the perioperative process which means that in this context cost-effectiveness interventions have consequences that also affect other fields, e.g. postoperative pain service besides anaesthesia. In conducting economic analyses, cost considerations or reductions cannot be targeted alone, but must always also integrate outcome aspects so that costs and quality are regarded in relation to one another.

Anesthesia↗

Effects of preinduction and intraoperative warming during major laparotomy.

We have investigated the influence of active warming before and during operation on blood loss, transfusion requirements, duration of stay in the post-anaesthesia care unit (PACU) and perioperative costs in 40 patients undergoing major abdominal surgery. Patients were allocated randomly to one of two groups: in the study group (n = 20), patients were actively warmed using forced air for 30 min before induction of general anaesthesia and during anaesthesia. Passive protection against heat loss consisted of circulating water mattresses, blankets and fluid warming devices, and was used both in the active warming group and in the control group (n = 20). At the end of surgery the change in core temperature was significantly less in the group of actively warmed patients (0.5 (SD 0.8) degree C vs 1.5 (0.8) degree C; P < or = 0.01). Blood loss and transfusion requirements were less in the actively warmed patients, who had a shorter duration of stay in the PACU (94 (SD 42) min vs 217 (169) min; P < or = 0.01) and a 24% reduction in total anaesthetic costs.

Adult↗

Evaluation of selected mathematical approaches to the kinetics of protein degradation in situ.

A linear model, two mathematical nonlinear models, and a curve-peeling procedure were used to estimate rate and extent of ruminal CP degradation of meat and bone meal (MBM) and soybean meal (SBM) from data obtained using the in situ Dacron polyester bag technique. Most of the values for extent of CP degradation of MBM were lowest when determined using curve peeling or the nonlinear models. In general, rates and extents of CP degradation of MBM estimated using the linear model and including ruminal incubations up to 12 h were greater than those obtained with the linear model and including ruminal incubations up to 24 h or up to 72 h. In addition, the models ranked the MBM samples differently for rate and extent of CP degradation. The results of the lack-of-fit test indicated that the linear model was inappropriate for estimating rate of degradation of MBM. However, CP degradation for SBM could be described by the linear model if long ruminal incubation times (greater than 48 h) were included in the calculations. Regression analyses were conducted to evaluate various compositional characteristics as predictors of CP degradation for MBM. Most of the correlation coefficients between CP degradation and the same independent variables were greater when the nonlinear models and curve peeling were used compared with the linear model. In general, the correlation coefficients between extent of CP degradation and the independent variables obtained with the linear model increased as the duration of ruminal incubations included in the model increased. Lysine concentrations, followed by CP solubility and ash content, were the best predictors of ruminal degradation of MBM protein. When using a specific mathematical model to predict CP degradation, analysis of residuals vs fitted and lack-of-fit tests should be performed to assess the validity of the model to describe the degradation patterns of the protein source under consideration. Also, long (at least 48 h) ruminal incubation times may be needed to correctly describe the pattern of CP degradation for MBM.

Animal Feed↗

Expression of the immunoglobulin superfamily cell adhesion molecule F3 by oligodendrocyte-lineage cells.

We have analysed the expression of glycosylphosphatidylinositol (GPI)-anchored proteins by oligodendrocyte-lineage cells. Biosynthetic labeling of mouse oligodendroglial primary cultures and an oligodendroglial precursor cell line demonstrated that these cells synthesise a variety of different GPI-anchored proteins. GPI-anchored proteins were isolated as a bulk preparation from the precursor cell line, and the individual proteins separated by 2D gel electrophoresis and analysed by microsequencing after tryptic digestion of the separated components. One of the most prominent GPI-anchored proteins synthesised by the cell line was identified as the cell adhesion molecule F3, previously thought to be exclusively expressed by neurons. Western blotting and immunoprecipitation with several polyclonal sera confirmed the expression of F3 by oligodendrocyte-lineage cells and demonstrated the presence of F3 in myelin. Double staining with a panel of oligodendrocyte-specific antibodies and anti-F3 antibodies of cerebellar cultures, as well as oligodendrocytes isolated by panning, showed a colocalization of F3 with oligodendrocyte markers. Oligodendrocyte F3 is shown to be susceptible to phosphatidylinositol-phospholipase C (PI-PLC) cleavage, similar to neuronal F3. Northern blots demonstrated that the oligodendroglial F3 mRNA is the same size as the neuronal message; however, no F3 mRNA could be detected in cortical astrocytes and an astrocytic cell line. Thus, in addition to the expression by neurons, the cell-type specificity of F3 expression must be extended to oligodendroglial cells, underscoring the importance of this Ig superfamily member in the nervous system.

Animals↗

Epidural abscess after combined spinal-epidural block.

PURPOSE: We report the first case of abscess formation after combined spinal-epidural block (CSE). Penetration of the dura in CSE may constitute an additional risk of subarachnoid spread of bacteria when post-puncture epidural infection is present. CLINICAL FEATURES: The combination of a spinal and a continuous epidural block (CSE) using a needle through needle technique was used in a 72-yr-old man for reconstructive vascular surgery of the lower limb. On the fourth postoperative day the patient demonstrated back pain, fever, and exudation of pus from the CSE-puncture site. An epidural abscess was diagnosed by magnetic resonance imaging and subsequently an emergency hemiaminectomy was performed. Physical examination and surgery did not show evidence of bacterial spread into the subarachnoid space. CONCLUSION: Epidural abscess formation after CSE may increase the risk of bacterial spread into the subarachnoid space. In this case spontaneous exudation and surgical drainage of abscess material may have prevented intrathecal infection. Rapid diagnosis and treatment of an epidural abscess appears particularly essential after CSE to prevent neurological sequelae.

Abscess↗

[Economic aspects of modern inhalation anesthetics with sevoflurane as an example].

The economic impact of the new German health care laws requires an awareness of cost-effectiveness when using newer drugs. The main goal in patient care, i.e., effective treatment, must be achieved by the rational use of restricted resources at a maximum degree of effectiveness. Economic aspects of the new inhalational anaesthetics such as sevoflurane are discussed in this article. The cost of inhalational anaesthetic agents accounts for up to 5% of all the running expenses of an anaesthesia department. The consumption and cost of an inhalational agent depend on fresh gas flow, vapour setting, and duration of anaesthesia. Comparing the cost for 1 MAC-h of anaesthesia, desflurane is more expensive at current market prices than sevoflurane and isoflurane. However, at low or minimal fresh gas flows, the price for one MAC-h is almost the same for these volatile anaesthetics. Total intravenous anaesthesia using propofol is even more expensive, partly due to wastage, i.e., opened ampoules with a remainder of propofol that has to be discarded after each case. When choosing an anaesthetic agent, the price of 1 ml liquid anaesthetic is an important factor. However, the overall cost-effectiveness analysis must balance the cost of the agent with its pharmacodynamic advantages such as more rapid recovery from anaesthesia. Furthermore, the indirect costs of side effects have to be taken into account. For example, nausea and vomiting lead to a prolonged stay in the recovery room after anaesthesia for outpatient surgery, which in turn incurs additional costs for antiemetic drugs and the extra time for nursing care. Therefore, a lower incidence of nausea and vomiting and a more rapid recovery from anaesthesia leading to earlier discharge from the recovery room may compensate for the higher price. Volatile agents account for up to 1% of the total intraoperative costs. In analysing the costs of 1 h of anaesthesia, other products such as plasma substitutes and blood products account for a much higher proportion than anaesthetic agents, and reductions or increases in costs pertaining to these products have a bigger impact on overall costs than do volatile anaesthetics. We conclude that volatile anaesthetics account for only a minor portion of the anaesthesia department budget and the cost of anaesthesia delivery. The higher market price of the new agents may be compensated for by the economic impact of fewer side effects and a shorter post-anaesthesia stay in the hospital. In analysing data for sevoflurane, this agent may be cost-effective, for example, for outpatient anaesthesia.

Anesthesia Department, Hospital↗

Effect of the 21-aminosteroid tirilazad mesylate on leukocyte adhesion and macromolecular leakage during endotoxemia.

BACKGROUND: Interstitial accumulation of leukocytes has been related to the development of multiple organ failure after sepsis. Oxygen radicals are involved in the process of leukocyte adherence to the microvascular wall. This study investigates the effects of the oxygen radical scavenger tirilazad mesylate on leukocyte-endothelial interactions, macromolecular leakage, and microhemodynamics in mesenteric venules during endotoxemia. METHODS: Male Wistar rats were randomly allocated to receive tirilazad mesylate (group A, n = 10), its vehicle (group B, n = 10), or saline 0.9% (group C, n = 10) before a 120-minute infusion of endotoxin (2 mg/kg/hr). Furthermore, a control group without receiving endotoxin (group D, n = 10) was investigated. Leukocyte adherence, emigration of leukocytes, and macromolecular leakage were determined in postcapillary venules of the mesentery by using intravital videomicroscopy. RESULTS: During the administration of endotoxin the number of adherent leukocytes per square millimeter of vessel surface progressively increased in group B (baseline, 431 +/- 35 cells/mm2; 120 minutes, 1121 +/- 71 cells/mm2) and group C (baseline, 398 +/- 44 cells/mm2; 120 minutes, 1290 +/- 116 cells/mm2). In group A no increase in leukocyte adherence was observed after 120 minutes (baseline, 415 +/- 81 cells/mm2; 120 minutes, 638 +/- 87 cells/mm2). In control animals the leukocyte adherence remained unchanged (baseline, 347 +/- 41 cells/mm2; 120 minutes, 507 +/- 75 cells/mm2). After 120 minutes, tirilazad mesylate prevented the increase in leukocyte emigration observed in group B and C. Increased macromolecular leakage during endotoxemia (groups B and C) was not influenced by pretreatment with tirilazad. Tirilazad did not affect the decrease in red cell velocity, volumetric blood flow, and venular shear rate observed during endotoxemia. CONCLUSIONS: This study demonstrates inhibitory effects of tirilazad on endotoxin-induced leukocyte adherence and emigration, suggesting a potential therapeutic role for this substance in the prevention of sepsis-induced multiple organ failure.

Animals↗

Gastric intramucosal pH: a predictor of survival in cardiac surgery patients with low cardiac output?

OBJECTIVE: To assess the value of gastric intramucosal pH measurement in patients with low output after cardiac surgery. DESIGN: Prospective clinical study. SETTING: University hospital. PARTICIPANTS: Fifteen patients with low output after cardiac surgery were included. Those who survived the first postoperative day (n = 14) remained in the study. INTERVENTIONS: Gastric intramucosal pH and arterial lactate concentrations were measured 6, 12, and 24 hours after admission to the intensive care unit. Intravenous infusion of buffer solutions was strictly avoided during the equilibration period and in the half hour before injection of saline into the gastric balloon of the tonometer. MEASUREMENTS AND MAIN RESULTS: Eight patients survived during the 28-day observation period, and six patients died. On admission to the intensive care unit, no difference in cardiac index (1.56 v 1.54 L/min/m2) or pulmonary capillary wedge pressure (17.3 v 17.7 mmHg) was found between survivors and nonsurvivors. During the first 24 hours after surgery, arterial lactate was significantly higher in the nonsurvivor group (61 v 23 mg/dL), but there was no difference between the gastric intramucosal pH of survivors and nonsurvivors (7.41 v 7.42 on admission). CONCLUSIONS: Calculated gastric mucosal pH is not an early predictor of survival in cardiac surgery patients with postoperative low cardiac output syndrome. Further studies are required to assess whether the gradient between arterial and intramucosal partial pressure of carbon dioxide (PCO2) might be a more useful predictive value.

Adult↗

In-use contamination of propofol. A clinical study.

Reports about post-operative infections associated with the use of propofol prompted us to investigate the in-use contamination of lipid-formulated intravenous (i.v.) anaesthetics used for general anaesthesia or for sedation of intensive care patients in this department. The level and incidence of extrinsic contamination of propofol ('Diprivan') and of another intravenous anaesthetic, etomidate, formulated in lipid solution ('Etomidat-lipuro') was found to be low during two study periods. However, the need to observe strict aseptic precautions in handling these intravenous drugs must be emphasized.

Anesthetics, Intravenous↗