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K Kirchhoff

Publications and source records attributed to K Kirchhoff.

18 recordsLinked to original sources
PubMed2005

The laryngeal tube for difficult airway management: a prospective investigation in patients with pharyngeal and laryngeal tumours.

BACKGROUND AND OBJECTIVE: Since the introduction of the laryngeal mask into clinical practice, various additional supraglottic ventilatory devices have been developed. Although it has been demonstrated that the laryngeal tube is an effective airway device during positive pressure ventilation no clinical study has been performed thus far regarding its use in patients with predicted ventilation and intubation difficulties. METHODS: The aim of this study was to prospectively evaluate the use of the laryngeal tube for temporary oxygenation and ventilation in adult patients with supraglottic airway tumours scheduled to undergo a pharyngeal-laryngeal oesophagoscopy and bronchoscopy under general anaesthesia. In addition to our standard airway management with face mask ventilation and rigid bronchoscopy, all patients were temporarily ventilated with an laryngeal tube. Also, in patients requiring laryngeal biopsies, endotracheal intubation was performed with a 6.0 mm microlaryngeal tracheal tube. Minute ventilation volumes, tidal volumes, ventilation pressures, end-expiratory CO2 concentration, oxygen saturation and arterial blood gas samples were measured. RESULTS: From 54 enrolled patients only patients with relevant tumour masses were evaluated (n = 23). Mask ventilation was performed without difficulty in 15 of 23 patients. Mechanical ventilation with the laryngeal tube was possible in 22 of 23 patients with an audible leak present in three. Conventional endotracheal intubation was successfully performed in 19 of 23 patients. During face mask ventilation, minute volume, tidal volume, ventilation pressure, end-tidal CO2, oxygen saturation and arterial PO2 were significantly lower and PCO2 significantly higher (P < 0.05, paired t-test). No statistically significant differences were noted between the laryngeal tube and the microlaryngeal tracheal tube. CONCLUSIONS: The possibility of difficult ventilation and intubation must always be considered, in patients with supraglottic airway tumours. In these cases, the laryngeal tube can be considered for routine airway management and may be useful in the 'cannot-intubate' situation although difficulties should be anticipated in patients with previous irradiation, specifically of the throat area.

Adult↗
PubMed2002

[Co-maintenance with propofol and midazolam: sympathoadrenergic reactions, hemodynamic effects, stress response, EEG and recovery].

OBJECTIVE: The study was undertaken to investigate the influence of TIVA with propofol, midazolam and fentanyl (comaintenance, COM-group) or TIVA with propofol and fentanyl (control-group) on sympathoadrenergic and hemodynamic reactions, stress response, EEG and recovery. METHODS: After ethical approval, 2 x 20 patients of ASA-risk I - III over 55 years of age undergoing visceral surgery were investigated in a prospective randomized design. For induction of anesthesia, patients of the COM-group received 0,05 mg/kg BW midazolam und 1,0 mg/kg BW propofol, and anesthesia was maintained with 0,05 mg/kg BW/h midazolam (until 15 - 30 min before the end of the operation) together with propofol in decreasing doses of 10 - 5 - 2 mg/kg BW/h. In the control-group, 2,0 mg/kg BW propofol were used for induction followed by decreasing doses of 10 - 5 - 2 mg/kg BW/h as well. Premedication (0,1 mg/kg BW midazolam orally) and weight-dependent doses of fentanyl (2,5 microgram/kg BW for induction, 1,25 microgram/kg BW 2 min before skin incision, further repetition doses of 1,25 - 2,5 microgram/kg/BW as required) and vecuronium were equal in both groups. Beyond consumption of anesthetics and recovery, sympathoadrenergic, other endocrine and hemodynamic reactions and SEF 90 were investigated at 7 time points before induction and postoperative recovery. alpha </= 0,05 was considered significant. RESULTS: Biometric data (mean age > 70 years) and duration of anesthesia and operation were comparable in both groups. Consumption of midazolam was higher in the COM-Group (14,8 vs. 7,5 mg; p = 0,004), whereas doses of fentanyl and vecuronium were comparable in both collectives. Recovery was significantly (p = 0,004) delayed in the COM-group: observing of simple orders 12,6 vs. 5,8 min, orientation with respect to person 19,8 vs. 9,9 min, local orientation 23,1 vs. 11,3 min. Mean arterial pressure in the COM-group was throughout lower than in the control-group, whereas heart rate was higher during the course of operation. Endocrine stress parameters (adrenaline, noradrenaline, antidiuretic hormone, adrenocorticotropic hormone, cortisol) and spectral edge frequency (SEF 90; Dräger-pEEG) were comparable in group level and time course between both groups. Plasma-concentrations of midazolam were significantly higher in the COM-group. CONCLUSION: In elderly patients undergoing visceral surgery in TIVA and when compared with propofol alone, no benefit of coinduction and comaintenance with midazolam and propofol could be demonstrated with respect to hemodynamic reactions and sympathoadrenergic and other endocrine stress response as well. Recovery was significantly delayed after administration of midazolam.

Aged↗
PubMed2001

Detection of anaphylatoxin receptors on CD83+ dendritic cells derived from human skin.

Dendritic cells (DC) are recruited to sites of inflammation for the initiation of immune responses. As the anaphylatoxins C5a and C3a are important mediators of inflammation, we investigated the expression of their receptors (C3aR and C5aR) on human DC. DC were isolated from human skin or generated from purified blood monocytes and were identified by their expression of CD1a or CD83. Freshly isolated or cultured dermal CD1a+ and CD83+ DC bound anti-C5aR and anti-C3aR monoclonal antibodies (mAbs), as detected by flow cytometry. C5a induced calcium fluxes in dermal CD1a+ and CD83+ DC, which could be inhibited by C17/5, an anti-C5a mAb. C3a did not induce calcium fluxes in these cells. Anaphylatoxin receptor expression was down-regulated on dermal DC by adding tumour necrosis factor-alpha (TNF-alpha) to the culture medium. On CD1a+ CD83- cells generated from isolated blood monocytes by culture with 6.25 ng/ml of granulocyte-macrophage colony-stimulating factor (GM-CSF) and 125 U/ml of interleukin-4 (IL-4), expression of both C5aR and C3aR was observed. In these cells, both C5a and C3a induced calcium fluxes. After addition of TNF-alpha to the culture medium, the majority of the CD1a+ cells expressed CD83+. These cells - expressing a phenotype of 'mature DC' - down-regulated the expression of the anaphylatoxin receptors and lost their reactivity to the respective ligands. Our results demonstrate the expression of the anaphylatoxin receptors C5aR and C3aR on human skin-derived DC and blood-derived cells expressing the DC-associated membrane molecule, CD1a. Furthermore, the expression of anaphylatoxin receptors on CD83+ dermal DC is indicative of an intermediate stage of maturation of these cells, which was not observed on in vitro-differentiated CD83+ cells.

Antigens, CD↗
PubMed2000

Activated human T lymphocytes express a functional C3a receptor.

The C3a molecule is an anaphylatoxin of the C system with a wide spectrum of proinflammatory effects predominantly on cells of myeloid origin. In this study we investigated the expression of the high affinity receptor for C3a (C3aR) in human T lymphocytes using receptor-specific mAb. C3aR expression was detected in CD4(+) and CD8(+) blood- or skin-derived T cell clones (TCC) from birch pollen-sensitized patients with atopic dermatitis. No significant difference in C3aR expression in CD4(+) or CD8(+) TCCs could be observed. In contrast to C3a(desArg), C3a led to a transient calcium flux in TCCs expressing the C3aR, whereas C3aR-negative TCCs were unreactive. Circulating T cells from patients suffering from severe inflammatory skin diseases expressed the C3aR, whereas no expression of C3aR could be found in unstimulated T lymphocytes from patients with mild inflammatory skin diseases or from healthy individuals. Type I IFNs, which are potent stimulators of cellular immunity, were identified as up-regulators of C3aR expression in vitro in freshly isolated or cloned T lymphocytes. Moreover, C3aR(+) T cells were found at the sites of injection in IFN-beta-treated patients with multiple sclerosis. These data provide direct evidence for the expression of C3aR on activated human T lymphocytes; this may point to a biological function of C3a in T cell-dependent diseases.

Antibodies, Monoclonal↗
PubMed2000

Orally administered lead chloride induces bias of mucosal immunity.

The hypothesis that lead disturbs gut immune functions upon oral ingestion was tested. Long-term exposure to oral PbCl(2)for 10 days caused persistent downregulation of TGF-beta mRNA levels in intestinal tissue. PbCl(2) also disturbed oral tolerance induction to the dietary antigen ovalbumin. Upon challenge with an immunizing dose of ovalbumin and rechallenge of draining lymph node cells in vitro, tolerance induction was partially suppressed in animals exposed to oral PbCl(2). This was shown by increased proliferation to antigenic stimulus, increased production of IFN-gamma and decreased secretion of TGF-beta. In conclusion, we show for the first time that oral exposure to PbCl(2)has a significant effect on the gut immune system, demonstrated by a bias of the cytokine pattern towards Th(1)and by disturbed oral tolerance mechanisms.

Administration, Oral↗
PubMed1999

C5a suppresses the production of IL-12 by IFN-gamma-primed and lipopolysaccharide-challenged human monocytes.

IL-12 is a key mediator of the immune response, skewing T lymphocytes toward a type 1 cytokine pattern. Priming with IFN-gamma or GM-CSF is required for expression of IL-12p70 by cells in which IL-12 is inducible by bacterial products such as LPS. We here show for the first time that the production of bioactive IL-12 by human monocytes can be significantly suppressed by C5a if applied to IFN-gamma-primed monocytes before LPS stimulation. There was a dose-dependent suppression by IL-12 (p70) on the levels of intracellular cytokine production and cytokine secretion. mRNA studies consistently showed a reduction of IL-12p40 and IL-12p35 expression by stimulation in the presence of C5a. The results of several different experimental approaches suggest that IL-12 down-regulation was not due to endogenous IL-10, IL-4, or PGE2 production induced by C5a. Moreover, stimulation of IFN-gamma-primed monocytes with C5a did not lead to a down-regulation of the CD14 Ag, which is an LPS receptor. These findings show that the anaphylatoxin C5a has the capacity to directly interact with the complex regulation of IL-12.

Adjuvants, Immunologic↗
PubMed1999

The gut cytokine balance as a target of lead toxicity.

The impact of exposure to lead on gut cytokine gene expression and oral tolerance was analyzed. Oral tolerization with ovalbumin (OVA) increased levels of IL-10 and TGF-beta in gut tissue while IFN-gamma mRNA levels remained unchanged in both autoimmune diabetes prone NOD and normal C57BL/6 mice. This shift towards Th2/Th3 type cytokine gene expression was completely abolished by concomitant treatment with PbCl2 (6 x 0.5 mg/kg) in NOD mice while the cytokine balance in C57BL/6 mice was unaffected. Suppression of Th2/Th3 type cytokine expression was associated with a dampened oral tolerance response to OVA as determined by T cell proliferation assays. We conclude that in autoimmunity prone NOD mice environmental toxicants may disturb immune homeostasis by targeting the gut immune system.

Administration, Oral↗
PubMed1999

Evaluation of C3a receptor expression on human leucocytes by the use of novel monoclonal antibodies.

Varying results have been published in the past regarding the reactivity of different leucocyte subpopulations, including neutrophils, monocytes and B lymphocytes, to the anaphylatoxin C3a and its degradation product C3a(desArg). To better characterize the cellular distribution of C3a receptor (C3aR) expression, monoclonal antibodies against two different epitopes on the third extracellular domain of the human C3aR were generated. Quantification of C3aR as compared with C5aR densities was performed on peripheral blood leucocytes by quantitative indirect immunofluorescence. Eosinophils and basophils expressed similar numbers of C3aR and C5aR molecules/cell. On eosinophils 10 700+/-4500 (mean+/-SD) C3aR and 14 700+/-4100 C5aR were found, whereas basophils carried 8100+/-2100 C3aR and 13 500+/-3800 C5aR. Monocytes expressed approximately six times more C5aR than C3aR molecules on their surface (6000+/-2500 C3aR versus 34 100+/-9300 C5aR molecules) whereas on neutrophils, the expression of C5aR was more than 20 times higher than the expression of C3aR (3100+/-1000 C3aR versus 63 500+/-12 200 C5aR). No C3aR expression was detectable on peripheral blood-derived B lymphocytes and on tonsillar B cells before and after stimulation with interleukin-2/Staphylococcus aureus Cowan strain I. Our findings correspond well with the paucity of data on C3a-induced functional activities in monocytes and neutrophils and suggest that eosinophilic and basophilic granulocytes represent the primary effector cells in the peripheral blood which can be stimulated by C3a.

Animals↗
PubMed1999

[The continuous monitoring of hepatic venous oxygen saturation in patient monitoring following hemihepatectomy].

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.

Adult↗
PubMed1999

Different effects of dopamine and dopexamine on the isolated perfused rat kidney.

We have investigated the effect of dopamine and dopexamine on the isolated perfused rat kidney. After an equilibration period of 20 min and two control periods of 10 min, dopexamine 1.0, 2.5 or 4.0 micrograms kg-1 min-1 or dopamine 2.0 micrograms kg-1 min-1 were perfused for a further 40 min in random order. Renal blood flow, urine volume, glomerular filtration rate, absolute sodium excretion and fractional sodium reabsorption of the isolated perfused kidney were measured every 10 min during the experiment. Dopamine increased significantly urine production from mean 61.54 (SEM 4.7) to 117.2 (9.7) microliters min-1 g-1 and absolute sodium excretion from 0.4 (0.1) to 1.2 (0.1) mumol min-1 g-1, and decreased significantly fractional sodium reabsorption from 97.3 (0.5) to 90.7 (0.7)%. Renal blood flow and glomerular filtration rate were not altered. In contrast, dopexamine had no effect on the isolated kidney. These data suggest that the diuretic and natriuretic effects of dopexamine in humans may not result from a direct action on the kidney.

Adrenergic beta-Agonists↗
PubMed1998

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.

Adult↗
PubMed1996

HCC-1, a novel chemokine from human plasma.

A novel CC chemokine, HCC-1, was isolated from the hemofiltrate of patients with chronic renal failure. HCC-1 has a relative molecular mass of 8,673 and consists of 74 amino acids including four cysteines linked to disulfide bonds. HCC-1 cDNA was cloned from human bone marrow and shown to code for the mature protein plus a putative 19-residue leader sequence. Mature HCC-1 has sequence identity of 46% with macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta, and 29-37% with the other human CC chemokines. Unlike MIP-1 alpha and the other CC chemokines, HCC-1 is expressed constitutively in several normal tissues (spleen, liver, skeletal and heart muscle, gut, and bone marrow), and is present at high concentrations (1-80 nM) in plasma. HCC-1 has weak activities on human monocytes and acts via receptors that also recognize MIP-1 alpha. It induced intracellular Ca2+ changes and enzyme release, but no chemotaxis, at concentrations of 100-1,000 nM, and was inactive on T lymphocytes, neutrophils, and eosinophil leukocytes. In addition, HCC-1 enhanced the proliferation of CD34+ myeloid progenitor cells. It was as effective as MIP-1 alpha, but about 100-fold less potent.

Amino Acid Sequence↗
PubMed1995

Release of urodilatin from perfused rat kidney and from cultured neonatal rat kidney cells.

Release of rat urodilatin (rURO) from isolated perfused rat kidneys and neonatal rat kidney cells could be demonstrated by a specific competitive radioimmunoassay (rURO-RIA) using [125I]rURO as the competitive antigen and an antiserum against the hypothetical rURO-N-terminus, Ala-Gly-Pro-Arg, as concluded from the amino acid sequence of the rat prohormone CDD/ANP-1-126. This antiserum did not react with synthetic rCDD/ANP-99-126, brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), or human URO (hURO). rURO could be demonstrated in the urine of the perfused rat kidney after an equilibration period of 20 min. After an initial slight decrease in the second 20 min, rURO production remained at almost the same level during the perfusion time of 100 min. A total of approximately 470 fmol.10 -1.g-1 kidney rURO was produced within 80 min. rURO was also produced by neonatal rat kidney cells kept in serum-free Dulbecco's modified Eagles medium. The production of rURO depended on the cultivation time of the cells. It increased up to 3 days reaching 239 +/- 7.5 fmol.h-1.g-1 protein, afterwards it decreased rapidly. The results obtained indicate that the rat kidney produces a peptide of the type A family of natriuretic peptides, which very likely represents the putative rURO.

Amino Acid Sequence↗
PubMed1991

[Positioning the central venous catheter using intra-atrial ECG].

In a small study (n = 9) central venous catheters were positioned in front of the right atrium using ECG. ECG was registered using a soft J-wire inside of the catheter. Big vessels were cannulated and in all cases cannulation was successful. ECG and x-ray control showed good agreement.

Catheterization, Central Venous↗
PubMed1986

Regulation of energy metabolism in pancreatic islets by glucose and tolbutamide.

The kinetics of insulin secretion and oxygen uptake in response to D-glucose and tolbutamide were compared in mouse pancreatic islets. In addition, the role of decreased ATP as a driving force for secretagogue-induced oxygen consumption was examined. D-glucose (10-30 mmol/l) triggered a biphasic insulin release which always coincided with a monophasic increase in islet oxygen uptake. In the presence of D-glucose (5-30 mmol/l), tolbutamide (3-500 mumol/l) consistently elicited an initial peak of insulin secretion which was followed by a continued decline. Tolbutamide-induced secretory profiles were accompanied by similar respiratory profiles. Oxygen consumption per ng of insulin released during the test phase was higher after elevation of the glucose concentration than after addition of tolbutamide. In conjunction with 5 or 10 mmol/l D-glucose, but not with 15 or 30 mmol/l D-glucose, tolbutamide (30-100 mumol/l) lowered islet ATP content significantly (p less than 0.02). Phosphocreatine was not found in isolated islets, although they contained substantial creatine kinase activity. It is concluded that the driving force for tolbutamide-induced oxygen uptake is a decrease in the phosphorylation potential caused by the work load imposed by stimulation of the secretion process. However, a major proportion of the respiratory response to glucose also results from enhancement of biosynthesis.

Animals↗
PubMedDate not supplied

Urodilatin inhibits sodium reabsorption in the isolated perfused rat kidney.

The effect of human urodilatin (hURO) on kidney function has been examined in stable recirculating isolated perfused rat kidney. The concentration-dependent effects of urodilatin (URO) on isolated perfused rat kidney were analyzed at different perfusion pressures. The experiments show that at perfusion pressures of 100 or 130 mm Hg, 100 nmol/l hURO cause a significant increase of urine flow and a significant decrease of the fractional sodium reabsorption from 95.2 (SD 0.9, n = 5) to 85.6% (SD 0.9, n = 5) and 86.8 (SD 1.6, n = 5) to 77.6% (SD 3.2, n = 5), respectively. In contrast, at a perfusion pressure of 80 mm Hg sodium excretion was not increased by URO. The glomerular filtration rate was unchanged. Furthermore, the renal effects of hURO were compared with rat urodilatin (rURO) and the circulating form of rat cardiodilatin/atrial natriuretic peptide (rCDD/ANP 99-126). hURO, rURO, and rCDD/ANP produced a concentration-dependent increase in sodium excretion. However, differences in natriuretic efficiency are observed. rCDD/ANP causes a decrease in fractional sodium reabsorption from 93.6 (SD 2.6, n = 5) to 86.8% (SD 2.4, n = 5), similar to hURO. rURO shows a significantly higher natriuretic effect decreasing fractional sodium reabsorption from 92.0 (SD 0.7, n = 5) to 79.1% (SD 1.2, n = 5). From these results we conclude that the response of the isolated kidney to URO is critically dependent on the perfusion pressure and that URO exhibits tubular action on renal sodium excretion. The observed differences among the tested peptides on renal function may be due to species differences in the peptide sequence.

Absorption↗