[Influence of a bolus injection of thiopental and propofol on the expression density of P-selectin and fibrinogen receptors on the surface of human platelets ex vivo]. / Einfluss einer Bolusgabe von Thiopental und Propofol auf die Expressionsdichte von P-Selektin und Fibrinogenrezeptoren auf der Oberfläche humaner Thrombozyten.

OBJECTIVE: Exposure of platelets to anaesthetic agents may alter their functional characteristics and in patients undergoing surgery or long-term sedation this may be clinically relevant. We investigated the influence of thiopentone and propofol on the expression of platelet membrane P-selectin, fibrinogen receptor, and leukocyte-platelet aggregates ex vivo. METHODS: In patients undergoing surgery blood samples were taken from a peripheral vein cannula before induction of anaesthesia with propofol (3.0 mg kg (-1) BW) or thiopentone (7.0 mg kg (-1) BW) and five minutes later (n = 11 in each group). Surface expression of the fibrinogen receptor complex (GP Ib/IIIa), P-selectin, and the percentage of leukocyte-platelet aggregates were measured by flow cytometry after stimulation via the ADP or thrombin receptor pathway. RESULTS: There was no significant difference in the expression of gpIIb/IIIa, P-selectin, and percentage of leukocyte-platelet aggregates in the thiopentone and propofol group after induction of anaesthesia. CONCLUSIONS: In clinically relevant concentrations thiopentone and propofol did not influence the surface expression density of fibrinogen receptors, P-selectin molecules, and the percentage of leukocyte-platelet aggregates ex vivo.

Scale-up of dialysis fermentation for high cell density cultivation of Escherichia coli.

In dialysis fermentations inhibiting metabolites can be removed from cell suspensions resulting in a prolonged exponential growth phase and higher production yields. Because of successful high cell density cultivations of Escherichia coli in a laboratory dialysis reactor, a scale-up of the process was investigated. To provide sufficient membrane area for dialysis in a technical scale fermenter, an external membrane module was used, that was also applied for oxygen supply to the culture in the external loop. Cultivations with recombinant E. coli K12, with and without induction, in 2- and 300-l reactors were carried out using external modules. Cell densities exceeding 190 g l(-1), previously obtained in laboratory dialysis fermentation, were also produced with external dialysis modules. Protein concentration in a 300-l reactor was increased to the 3.8-fold of industrial fed-batch-fermentations.

Cell surface heparan sulfate is a receptor for human herpesvirus 8 and interacts with envelope glycoprotein K8.1.

An immunodominant envelope glycoprotein is encoded by the human herpesvirus 8 (HHV-8) (also termed Kaposi's sarcoma-associated herpesvirus) K8.1 gene. The functional role of glycoprotein K8.1 is unknown, and recognizable sequence homology to K8.1 is not detectable in the genomes of most other closely related gammaherpesviruses, such as herpesvirus saimiri or Epstein-Barr virus. In search for a possible function for K8.1, we expressed the ectodomain of K8.1 fused to the Fc part of human immunoglobulin G1 (K8.1DeltaTMFc). K8.1DeltaTMFc specifically bound to the surface of cells expressing glycosaminoglycans but not to mutant cell lines negative for the expression of heparan sulfate proteoglycans. Binding of K8.1DeltaTMFc to mammalian cells could be blocked by heparin. Interestingly, the infection of primary human endothelial cells by HHV-8 could also be blocked by similar concentrations of heparin. The specificity and affinity of these interactions were then determined by surface plasmon resonance measurements using immobilized heparin and soluble K8.1. This revealed that K8.1 binds to heparin with an affinity comparable to that of glycoproteins B and C of herpes simplex virus, which are known to be involved in target cell recognition by binding to cell surface proteoglycans, especially heparan sulfate. We conclude that cell surface glycosaminoglycans play a crucial role in HHV-8 target cell recognition and that HHV-8 envelope protein K8.1 is at least one of the proteins involved.

[Epstein-Barr virus genome positive lymphoepithelioma-like carcinoma of the stomach]. / A gyomor Epstein-Barr-vírusgenom pozitív lymphoepitheliomaszerú carcinomája.

EBV is associated with a high number of tumours and non-tumourous conditions. The rare lymphoepithelioma like carcinoma of the stomach,--just as similar tumours of foregut origin (thymus, lung, salivary gland)--are frequently EBV genom positive with the expression of only a few genes (EBV nuclear antigen 1, EBV encoded ribonucleoproteins/EBER/, latency I). On the basis of the clinicopathological analysis of two cases and literature data the authors point out the male predominance and the relatively favourable prognosis of the patients, furthermore the frequent cardial-subcardial localization of these tumours. Since the frequent non-lymphoepithelioma like stomach tumours,--adenocarcinomas,--show EBV genom positivity in about 1% of the cases, it is concluded that the characteristic lymphoepithelioma like histological pattern is not a sine qua non condition of EBV genom positivity. It may also be assumed, that the CD8 and TIA 1 cytotoxic lymphocytes are not virus but tumour cell specific, however not efficient, perhaps not activated. The low level of apoptotic tumour cells supports this assumption. In one of the cases a double tumour, a genom positive lymphoepithelioma like carcinoma and a genom negative adenocarcinoma, adjacent to each other was seen which speaks in favour of common carcinogenetic factors and shows that microscopic neighbourhood is not a necessary condition in viral association. The origin of the possible oncogenic effect of EBV in the absence of the transforming gene products latent membrane protein 1 and EBNA 2 in genom positive stomach carcinomas is uncertain. The significance of the presence in both cases of CD 5+ tumour cells is not clear, the study of further cases is indicated.

An improved procedure for the generation of recombinant single-chain Fv antibody fragments reacting with human CD13 on intact cells.

A procedure was developed to generate recombinant single chain Fv (scFv) antibody fragments reacting with the extracellular domain of human cell surface antigen CD13 (hCD13; aminopeptidase N) on intact cells. Membrane fractions prepared from a stably transfected hCD13-positive murine NIH/3T3 cell line were used to immunize BALB/c mice, with the intention that hCD13 would be the major immunogenic molecule recognized by the immune system. Spleen RNA from the immunized mice served to generate a combinatorial scFv phage display library. The library was adsorbed against non-transfected NIH/3T3 or Sf21 insect cells to eliminate nonrelevant binders. The supernatant was then used for panning with either hCD13-transfected Sf21 insect cells or a hCD13-expressing human leukemia-derived cell line. Therefore, the key concepts of the procedure were the presentation of hCD13 as the sole human antigen on murine NIH/3T3 cells and a screening strategy where hCD13 was the major common antigen of the material used for immunization and panning. Two different hCD13-reactive phages were isolated and the soluble scFvs were expressed in E. coli and purified. The two scFvs, anti-hCD13-1 and anti-hCD13-3, differed at four amino acid positions in their V(H) regions and both had high affinities for hCD13 as determined by surface plasmon resonance (K(D)=7 and 33x10(-10) M, respectively). Both efficiently recognized hCD13 on intact cells. Therefore, the procedure allowed the production of high affinity scFvs reacting with a desired antigen in its native conformation without requiring extensive purification of the antigen and should be useful for the preparation of scFvs against other conformation-sensitive cell-surface antigens.

Low-dose dopexamine in patients undergoing hemihepatectomy: an evaluation of effects on reduction of hepatic dysfunction and ischaemic liver injury.

BACKGROUND: Hepatic dysfunction is a common problem in patients after hemihepatectomy. Treatment with low-dose dopamine has been shown to be beneficial in hemihepatectomy patients. We hypothesized that dopexamine, a synthetic vasoactive catecholamine, due to its specific pharmocodynamic profile may be more effective in reducing hidden ischaemic episodes in the hepato-splanchnic region during and after temporary total cross-clamping of hepatic inflow in these patients. METHODS: The effects of low-dose dopexamine on hepatic venous haemoglobin oxygen saturation (ShvO2), hepatic venous lactate level, monoethylglycinxylid (MEGX) formation, hepatic synthetic function and indicators for hepatic cell damage were studied during hemihepatectomy and for 16 h postoperatively in hemihepatectomy patients and compared to those of low-dose dopamine. In a prospective, double-blind clinical study 20 patients received randomly either dopexamine (DPX) 0.5 microg kg(-1) min(-1) (n=10) or dopamine (DO) 2.5 microg kg(-1) min(-1) (n= 10). Infusions were started after induction of anaesthesia and continued 16 h postoperatively. Hepatic vein, radial and pulmonary artery were catheterized. Measurements were carried out after induction of anaesthesia, after total cross-clamping of hepatic inflow, and at 2 h and 16 h postoperatively. RESULTS: There were no differences in systemic haemodynamics, oxygenation, ShvO2, serum aminotransferases or MEGX levels between the groups. At 16 h postoperatively prothrombin and antithrombin III levels were significantly lower while hepatic venous lactate was significantly higher in the DPX group compared to the DO group. CONCLUSION: In patients undergoing hemihepatectomy, we could not reveal superior hepatoprotective effects of low-dose dopexamine compared to low-dose dopamine.

Carbon catabolite repression in Lactobacillus pentosus: analysis of the ccpA region.

The catabolite control protein CcpA is a central regulator in low-G+C-content gram-positive bacteria. It confers carbon catabolite repression to numerous genes required for carbon utilization. It also operates as a transcriptional activator of genes involved in diverse phenomena, such as glycolysis and ammonium fixation. We have cloned the ccpA region of Lactobacillus pentosus. ccpA encodes a protein of 336 amino acids exhibiting similarity to CcpA proteins of other bacteria and to proteins of the LacI/GalR family of transcriptional regulators. Upstream of ccpA was found an open reading frame with similarity to the pepQ gene, encoding a prolidase. Primer extension experiments revealed two start sites of transcription for ccpA. In wild-type cells grown on glucose, mRNA synthesis occurred only from the promoter proximal to ccpA. In a ccpA mutant strain, both promoters were used, with increased transcription from the distant promoter, which overlaps a presumptive CcpA binding site called cre (for catabolite responsive element). This suggests that expression of ccpA is autoregulated. Determination of the expression levels of CcpA in cells grown on repressing and nonrepressing carbon sources revealed that the amounts of CcpA produced did not change significantly, leading to the conclusion that the arrangement of two promoters may ensure constant expression of ccpA under various environmental conditions. A comparison of the genetic structures of ccpA regions revealed that lactic acid bacteria possess the gene order pepQ-ccpA-variable while the genetic structure in bacilli and Staphylococcus xylosus is aroA-ccpA-variable-acuC.

Glucose kinase of Streptomyces coelicolor A3(2): large-scale purification and biochemical analysis.

Glucose kinase of Streptomyces coelicolor A3(2) is essential for glucose utilisation and is required for carbon catabolite repression (CCR) exerted through glucose and other carbon sources. The protein belongs to the ROK-family, which comprises bacterial sugar kinases and regulators. To better understand glucose kinase function, we have monitored the cellular activity and demonstrated that the choice of carbon sources did not significantly change the synthesis and activity of the enzyme. The DNA sequence of the Streptomyces lividans glucose kinase gene glkA was determined. The predicted gene product of 317 amino acids was found to be identical to S. coelicolor glucose kinase, suggesting a similar role for this protein in both organisms. A procedure was developed to produce pure histidine-tagged glucose kinase with a yield of approximately 10 mg/l culture. The protein was stable for several weeks and was used to raise polyclonal antibodies. Purified glucose kinase was used to explore protein-protein interaction by surface plasmon resonance. The experiments revealed the existence of a binding activity present in S. coelicolor cell extracts. This indicated that glucose kinase may interact with (an)other factor(s), most likely of protein nature. A possible cross-talk with proteins of the phosphotransferase system, which are involved in carbon catabolite repression in other bacteria, was investigated.

[Circulatory function and oxygenation during hemihepatectomy. Dopamine versus dopexamine]. / Kreislaufverhalten und Oxygenierung während Hemihepatektomien. Dopamin versus Dopexamin.

OBJECTIVE: The aim of this study was to compare low dose dopamine and dopexamine with respect to of liver-venous oxygen saturation, oxygen delivery and--demand, liver function tests and cardiocirculatory effects in the reperfusion period during a hemihepatectomy operation with occlusion of the liver hilus. METHODS: Twenty patients were studied in a randomised, doubleblind setting. They either received 2 micrograms/kg per min dopamine or 0.5 microgram/kg per min dopexamine perioperatively. For monitoring purposes a pulmonary artery and a liver venous catheter were placed. At four different time points hemodynamic parameter were assessed and blood samples were drawn. RESULTS: Significant changes between groups were found 5 min after opening the liver hilus for the cardiac index and the systemic oxygen delivery, as well as at the end of the operation for pulmonary shunt volume, which had increased more in the dopexamine group. No significant difference between liver venous oxygen saturation and liver function tests was found. CONCLUSION: Until more detailed studies concerning the influence of dopamine on the hepatic-splanchnic region during liver surgery are performed, dopexamine can not be considered superior to dopamine during these operations.

[The continuous monitoring of hepatic venous oxygen saturation in patient monitoring following hemihepatectomy]. / Die kontinuierliche Uberwachung der lebervenösen Sauerstoffsättigung als erweitertes Monitoring während einer Hemihepatektomie.

UNLABELLED: Increasing numbers of liver tumours and liver metastases from other tumours are treated by liver resection. During resection the ligamentum hepatoduodenale is occluded and the liver is exposed to warm ischemia. Duration and intensity of resulting liver ischemia can not be evaluated without special monitoring devices. A fiberoptic catheter placed in a liver vein facilitates continuous recording of the hepatic-venous oxygen saturation (ShvO2). CASE REPORT: We present a case where such a catheter was placed perioperatively in a patient undergoing hemihepatectomy. The liver venous catheter was positioned by guidance of the saturation curve and X-ray. The preoperative oxygen saturation in this liver vein was 80%. During the whole operation, the ShvO2 was continuously monitored. Blood for blood gas analyses was drawn before, during and after the occlusion of the ligamentum hepatoduodenale. Hemodynamic parameters were documented at the same time. The ShvO2 already decreased in the preparation period before the actual occlusion of the ligamentum hepatoduodenale. During the occlusion the ShvO2 dropped to an average of 30% with the lowest value being 13%. After reopening of the hepatic hilus the ShvO2 increased rapidly but did not reach preoperative values which were recorded not earlier than at the end of the operation. CONCLUSION: Duration and intensity of the decreased ShvO2 were recognized early by the liver venous catheter. It was demonstrated that desaturation of the hepatico-splanchnic region already occurred during the period of liver preparation before the ligamentum hepatoduodenale was occluded. Interventions to protect the liver from ischemia should therefore be applied some time before occlusion of the liver hilus. However, clearly defined indications for this invasive monitoring cannot be given at this time. In situations of extended liver resection or in cases of expected technical difficulties a continuous monitoring of the liver-venous oxygen saturation might be beneficial.

The surgical technique of isolated hyperthermic arterial liver perfusion in humans.

Various techniques of isolated liver perfusions have been described, using hepatic artery or both hepatic artery and portal vein. In this paper the technique of isolated arterial liver perfusion is presented. Twelve patients suffering from non-resectable liver tumors underwent this approach. All of them had been previously unsuccessfully treated by resection or systemic chemotherapy. The liver perfusions were performed without technical problems. No operative death occurred. The mean operating time was 413 +/- 29 min. Although the perfusion medium was oxygenated and the absolute anoxic period was shorter than 10 min in all cases the perfused livers showed a marked postoperative increase of liver enzyme levels. Further studies should be aimed at reducing this hepatic injury and simplifying the complex surgical procedure.

Anesthesiological management during isolated liver perfusion.

The treatment of irresectable hepatic metastases is limited by the systemic toxicity of anticancer agents. Isolated hyperthermic liver perfusion (IHLP) with anticancer agents is a new therapy for irresectable liver tumors. The risks of this therapy lie in the extended operation, the anhepatic phase and the possibility of liver damage due to the anticancer drug and hyperthermia. Experience of this method is rare, and the side effects are not well known. To estimate the individual risk of patients before isolated liver perfusion an extended evaluation of the preoperative conditions is usual. Titration of all anesthetic agents is advisable to prevent cardiovascular changes and to avoid an extended recovery time after therapy. Based on our experience with IHLP in ten patients, we prefer coinduction with midazolam and thiopentone. After intubation, intermittent positive pressure ventilation with positive end-expiratory pressure is instituted with 30% oxygen in air. Pancuronium bromide is used to provide muscular paralysis, and isoflurane is administered throughout the procedure. Anesthesia is supplemented by fentanyl and midazolam. Invasive hemodynamic monitors may be placed after induction of anesthesia. Our first results with IHLP indicate that, under the conditions of elevated monitoring, complete isolation of the liver, a good wash-out and a safe anesthesiological management, no major disturbances must be expected during the therapy. The patients are more compromised by the therapy during the following days. Low diastolic blood pressure and loss of resistance after perfusion were the first signs of a toxic reaction.

[Anesthesiologic characteristics of isolated hyperthermic liver perfusion with mitomycin C]. / Anästhesiologische Besonderheiten bei der isolierten hyperthermen Leberperfusion mit Mitomycin C.

The isolated hyperthermic liver perfusion with mitomycin C presents a new technique of regional therapy for irresectable liver tumours. The advantage is a high local concentration of the antitumour agent with reduced systemic side-effects. Isolated hyperthermic liver perfusion is an extensive surgical procedure requiring a veno-venous bypass and a heart-lung machine. Disturbances affecting the base-acid hemostasis, the coagulation system and the cardiocirculatory function can occur. To date, there has been little experience with this technique. The intraoperative changes during the isolated hyperthermic liver perfusion in our series were similar to those seen during orthotopic liver transplantation. In contrast to orthotopic liver transplantation, heparin is given during the anhepatic phase. The reperfusion after isolated hyperthermic liver perfusion was not complicated by severe cardiocirculatory changes. A decrease in body temperature was not observed probably due to the absence of cold, potassium-rich perfusate flowing into the systemic circulation. Two patients developed signs of a reperfusion syndrome within the first hour after reperfusion (decrease in peripheral systemic resistance).

[Endocrine reactions, circulatory and resuscitation behavior in ketamine-midazolam anesthesia. A comparative study of ketamine racemate vs. (S)-ketamine in knee surgery]. / Endokrine Reaktionen, Kreislauf- und Aufwach-verhalten bei Ketamin-/Midazolam-Narkosen. Eine Vergleichsstudie Ketamin-Razemat vs. (S)-Ketamin bei Eingriffen am Knie.

UNLABELLED: Clinically used ketamine is a racemic mixture of two isomers, (S)- and (R)-ketamine, in equal amounts. Previous investigations showed the anaesthetic potency of (S)-ketamine to be three times higher than that of (R)-ketamine. The aim of this study was to compare the effects of (S)-ketamine/midazolam and racemic ketamine/midazolam on endocrine and cardiovascular parameters, recovery, and side effects in unpremedicated patients during knee surgery. METHODS: 41 patients scheduled for elective knee surgery were investigated in a prospective, double-blind, and randomised design. For induction of intravenous anesthesia, patients received 0.1 mg/kg midazolam, 0.003 mg/kg atropine, 1 mg/kg (S)-ketamine or 2 mg/kg racemic ketamine, respectively. For tracheal intubation, 1 mg vecuronium and 1.5 mg/kg suxamethonium were injected. After intubation and relaxation with a total dose of 0.1 mg/kg vecuronium, a continuous infusion of 0.5 mg/kg/h (S)- or 1 mg/kg/h racemic ketamine was administered throughout the surgery. In addition, 0.05 mg/kg/h midazolam was infused continuously in both groups throughout surgery. Ventilation was performed with N2O/O2 (FiO2 0.3). Blood samples were taken using a central venous line five times before induction as well as during and after surgery for analysis of adrenaline, noradrenaline (by high-pressure liquid chromatography with electrochemical detection), anti-diuretic hormone (ADH), adrenocorticotropic hormone (ACTH), and cortisol (by radioimmunoassay). In addition, systolic and diastolic arterial pressure (SAP, DAP), heart rate (HR), and arterial oxygen saturation were measured. The time intervals between the end of ketamine and midazolam infusion and the return of consciousness and orientation were recorded. The incidence and quality of dreams and other side effects were reported by the patients. RESULTS: Biometric data of the groups were comparable. Plasma adrenaline and noradrenaline did not change significantly during anaesthesia. ADH increased significantly (p < 0.05) after skin incision in both groups.

Cardiopulmonary effects of lying position in anesthetized and mechanically ventilated dogs.

Cardiopulmonary effects of right-lateral and supine (on back) lying position were investigated in 8 anesthetized and mechanically ventilated dogs. Complete hemodynamic and respiratory monitoring were obtained. Heart rate was significantly higher, blood pressure, systemic vascular resistance and left and right ventricular stroke work were significantly lower in supine in comparison to right-lateral position. Arterial and mixed-venous oxygen tensions and mixed-venous oxygen saturation were significantly higher in right-lateral position. Compliance was significantly higher and peak ventilation pressure significantly lower in supine position. Arterio-to-mixed-venous-oxygen content difference, oxygen consumption and utilization were significantly higher and respiratory quotient was significantly lower in supine position in comparison to right-lateral position. All other obtained parameters were not be influenced by posture.

[Muscle relaxation with atracurium in myasthenia gravis]. / Muskelrelaxation mit Atracurium bei Myasthenia gravis.

This report concerns a narcosis in a 42-year-old female patient suffering from myasthenia gravis in a state of clinical remission after thymectomia. Six months after thymectomia relaxometric control (Datex AMG) was performed while the patient underwent major colorectal surgery. We found a persisting sensitivity to relaxants during isoflurane anaesthesia supplemented with fentanyl. During 270 minutes of anaesthesia we needed only 25 mg atracurium (0.4 mg/kg bodyweight) only 57% of a theoretical normal dose. This is the result of a continuing muscular weakness in asymptomatic patients suffering from clinically reliable myasthenia gravis. Therefore, a reduced demand for muscle relaxants can be expected in these patients.

[Mediastinal tumor and airway obstruction in general anesthesia. Case report and review of the literature]. / Mediastinaltumor und Luftwegsobstruktion unter Allgemeinanästhesie. Fallbeispiel und Literaturüberblick.

Case report of an acute airway obstruction during general anaesthesia by compression of the left main bronchus in an asymptomatic patient with unknown mediastinal mass. The patient was scheduled for a relief of a thyroid gland cyst. The compression occurred after uneventful induction of anaesthesia during the patient's positioning with flexed neck and elevated upper thorax on a pad. Increasing FiO2 from 0.5 to 1.0, repeated fiberoptic bronchoscopic examination and changing of the position of the endotracheal tube facilitated the operation. After reversal of the flexed neck position ventilation was normal. The intraoperatively suspected mediastinal tumour was confirmed by postoperative computerised tomography of thorax and neck. The teratoma was removed in toto in a second operation. In a review of the literature pathophysiological changes, preoperative assessment and anaesthetic management of patients with mediastinal tumour are discussed.

Effects of immediate postoperative enteral nutrition on body composition, muscle function, and wound healing.

Thirty-two patients undergoing bowel resection were randomized to receive either immediate postoperative nasojejunal feeding with full strength Osmolite solution for 56 hours (n = 16) or routine postoperative hypocaloric fluids and gradual reintroduction of diet (n = 16). Body composition changes were measured at 14 days after operation with in vivo neutron activation analysis, the wound healing response by subcutaneous implantation of Gortex tubes, and muscle function by grip strength, maximum ventilatory volume, and stimulation of the ulnar nerve at the wrist. Postoperative fatigue up to 3 months after operation was assessed using a 10-point analogue. Successful immediate enteral nutrition was established in 12 of the 16 patients. Enterally fed patients had a mean daily caloric intake of 1179 +/- 388 kcal/d (mean +/- SD) over the first 4 postoperative days compared with 382 +/- 71 kcal/d for the controls (p less than 0.0001). The amount of hydroxyproline accumulating in the Gortex tubes was also significantly greater (2.5 +/- 1.1 nmol/g tube vs 1.5 +/- 0.8 nmol/g tube; p less than 0.02). However, the amount and composition of the weight lost was not significantly different. Muscle function was not preserved, and postoperative fatigue occurred to an equal extent in both groups. Complications were similar in both groups, except for a preponderance of bowel obstructions in the controls. The time to passage of first flatus and first bowel motion, although shorter in the fed group, did not reach significance (p = 0.07). We conclude that immediate enteral nutrition is feasible and results in an improved wound healing response.(ABSTRACT TRUNCATED AT 250 WORDS)

Electron spin resonance of erythrocytes in Huntington's disease.

Electron spin resonance (ESR) studies were carried out with MAL-6 as spin label on erythrocytes from 21 patients with Huntington's disease (HD) and 18 controls. No significant difference was found between the ESR spectra from HD patients and controls. These findings do not support the theory that HD is a generalized membrane defect.