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Biomedical subjects

M Hornung

Publications and source records attributed to M Hornung.

At least 19 recordsLinked to original sources
PubMed2006

Mini-incision for strictly retroperitoneal nephrectomy in living kidney donation vs flank incision.

BACKGROUND: Mini-incision donor nephrectomies (MIDNs) were established during the last decade, as an alternative to traditional open donor nephrectomy (ODN) via flank incision. In this study, we investigated intra-operative and post-operative data on outcome following MIDN in comparison with ODN data. METHODS: Data of 70 living kidney donations, performed at the University of Regensburg Medical Center since 1996, were evaluated. Donor operation was performed as either strictly retroperitoneal MIDN (n = 34) or as traditional ODN (n = 36) via flank incision. Total operation time, warm ischaemia time (WIT), perioperative pain-medication usage and creatinine levels as well as length of hospital stay, return to complete enteral nutrition and regular digestion were evaluated retrospectively. RESULTS: Total operation times were similar in MIDN, n = 34 (132 +/- 26 min) and in ODN, n = 36 (140 +/- 37 min) (P = 0.424). WIT was also similar in both: MIDN (0.9 +/- 0.4 min) and ODN (0.9 +/- 0.4 min) (P = 0.568). The requirement for post-operative opioids in morphine equivalent doses was significantly lower in MIDN (8.4 +/- 16 mg) compared with ODN (44 +/- 57 mg) (P = 0.001). Additional application of non-opioids (metamizole) (MIDN: 4.8 +/- 6.3 g, ODN: 3.4 +/- 3.9 g) and non-steroidal antirheumatic (NSAR) (diclofenac) (MIDN: 322 +/- 361 mg, ODN: 247 +/- 474 mg) revealed no significant differences between the groups. The hospital stay was 4.9 +/- 1.4 days in MIDN which was significantly shorter than that in ODN (9.3 +/- 3.3 days) (P = 0.001). Patients achieved fully independent mobility earlier in MIDN than in ODN (P = 0.934). Start of enteral nutrition with fluids was significantly quicker in MIDN (1.9 +/- 7 h) compared with ODN (12 +/- 13 h) (P = 0.05). Full enteral nutrition was accomplished significantly earlier in MIDN (1.6 +/- 0.8 days) (P = 0.023). Return to normal digestion revealed no significant differences between groups. Serum creatinine levels of all kidney donors were in the normal range (66 +/- 18 micromol/l) one day before nephrectomy, increased on day 1 after surgery (119 micromol/l +/- 31 micromol/l) and were stable on day 3 (115 micromol/l +/- 30 micromol/l) without significant differences. CONCLUSION: Strictly, retroperitoneal MIDN in living kidney donation is a fast and safe method for the procurement of a living donor graft, giving the patient a significantly shorter period of recovery, and thus is an attractive and recommendable alternative to traditional ODN procedures.

Adult↗
PubMed2006

[Pararectal mini-incision for strictly retroperitoneal nephrectomy in living kidney donation].

PURPOSE: In this study we present the technique of a strictly retroperitoneal donor nephrectomy via a pararectal mini-incision. MATERIAL AND METHODS: Data of 34 living kidney donations were analyzed. All donors underwent a pararectal mini-incision and strictly retroperitoneal nephrectomy (MIDN). RESULTS: Total operation time, perioperative use of pain medication, length of hospital stay after successful mobilization, and return to full enteral nutrition and regular digestion were evaluated retrospectively. Total operation time for MIDN was 132+/-26 min. The total average application was 22.2+/-19.4 mg of opioid in morphine equivalent dosage (MED), 7.7+/-6.1 g metamizol, and 512+/-325 mg NSAR during hospital stay, which was 4.9+/-1.4 days. Patients were mobilized primarily 2.9+/-8.0 h after surgery. Mobility was achieved 33.8+/-15.8 h after surgery. Enteral nutrition with fluids was started after 1.9+/-7.0 h, full enteral nutrition was accomplished after 37.4+/-19.0 h, and normal digestion returned 58.6+/-23.0 h after the procedure. CONCLUSIONS: The strictly retroperitoneal nephrectomy via a mini-incision is an elegant, minimally traumatic, safe, and quickly learnable method, resulting in short hospital stays, good cosmetic results, and a low grade of complications.

Adult↗
PubMed2005

Short-term treatment with anti-CD44v7 antibody, but not CD44v4, restores the gut mucosa in established chronic dextran sulphate sodium (DSS)-induced colitis in mice.

Increased expression of CD44 variant isoforms have been shown on the inflammatory infiltrates in human and mouse colitis and blockade or deletion of CD44 isoforms inhibit experimental colitis. The objective of this study was to find out if short-term treatment of CD44 antibodies specific to CD44v7, but not to other variant isoforms, suppresses leucocyte-endothelial interaction in chronic dextran sodium sulphate (DSS)-induced colitis in mice. Chronic colitis was induced by oral administration of four cycles of 5% DSS in BALB/c mice. Expression of CD44 was investigated on isolated mononuclear cells of the gut immune system. In established colitis, mice were treated with antibodies against CD44v7 or CD44v4 three times in 7 days. Intravital microscopy was used to study leucocyte-endothelial interactions and leucocyte extravasation. As a marker of inflammatory infiltrates myeloperoxidase was quantified in gut tissue. CD44-induced apoptosis was determined by fluorescence staining of hypodiploidic cell nuclei. In chronic DSS-induced colitis both CD44 variant isoforms, v4 and v7 were significantly up-regulated on mononuclear cells. However, whereas anti-CD44v7 antibody treatment induced a marked restoration of the gut mucosa and significantly reduced endothelial sticking and extravasation of circulating leucocyte in vivo (P < 0.01), application of anti-CD44v4 or an isotype control antibody had no anti-inflammatory effect. A significant reduction of myeloperoxidase activity was detected after blockade of CD44v7, but not v4. Short-term treatment with anti-CD44v7 antibody blocks T cell extravasation and recruitment to the intestinal mucosa and cures established experimental colitis.

Animals↗
PubMed2003

Assessing stock and change in land cover and biodiversity in GB: an introduction to Countryside Survey 2000.

Countryside Survey 2000 (CS2000) is the latest in a series of surveys designed to measure and evaluate stock and change of land cover, landscape features, freshwaters, habitats and the vegetation of Great Britain. The ideas behind CS2000 developed during the 1960s and 1970s and culminated in the first survey of vegetation and land cover in 1978. One kilometer sample squares were selected at random using an environmental stratification. Subsequent surveys took place in 1984, 1990 and 1998, revisiting the original sample locations, whilst progressively expanding in scope and sample size; CS2000 included soils, breeding birds, remotely sensed imagery, freshwater biota and hydromorphology. Countryside Survey data may be interpreted using the pressure-state-response model, by selecting indicators of process and quality, and by identifying models of expected responses to different pressures. Thus, results showing losses of hedgerows between 1984 and 1990 stimulated new protection for these features. Ideally, CS2000 data should be used to stimulate experiments to distinguish between different pressures, in order to ensure that policy and management responses are both appropriate and achievable.The experience from CS2000 may prove helpful for the design and management of other large scale monitoring programmes of ecosystems. In particular, the scope of the survey, and the use to which the data are applied, have evolved through time, and yet continuity was essential for change to be detected efficiently. These objectives were reconciled by collecting the data in a disaggregated form, allowing a high degree of flexibility in both analysis and reporting.

Animals↗
PubMed2003

Assessing soil biodiversity across Great Britain: national trends in the occurrence of heterotrophic bacteria and invertebrates in soil.

An assessment of the biodiversity of soils was a component of the Countryside Survey 2000 (CS2000). This was the first integrated survey of soil biota and chemical properties at a national scale. A total of 1052 soil samples were collected across Great Britain during CS2000 and analysed for a range of soil microbial and invertebrate characteristics resulting in the production of a series of robust datasets. A principal objective was to use these datasets to investigate relationships between soil biota and environmental factors such as geographical location, vegetation, land use, land cover, soil type and pollutant levels as first stages in characterising the inherent biodiversity of British soils and investigating the potential of soil biodiversity as indicators of soil health at a regional or national scale. Preliminary results for culturable heterotrophic, invertebrate taxa, Acari, Collembola and Oribatid mites are presented here to illustrate the nature of the data collected and the patterns of soil biodiversity in relation to large-scale regional, vegetation and soil characteristics across the British countryside.

Animals↗
PubMed1998

The CD40 TRAF family member interacting motif carries the information to rescue WEHI 231 cells from anti-IGM-induced growth arrest.

Engagement of the antigen receptor on WEHI 231 murine B lymphoma cells leads to growth arrest and induction of apoptosis. Concomitant signaling through CD40 sustains proliferation and rescues the cells from apoptosis. At the molecular level, CD40 has been shown to activate nuclear factor kappaB (NF-kappaB) and stress-activated protein kinase (SAPK). The aim of our present study was to define the stretch of the CD40 cytoplasmic tail responsible for mediating these effects in WEHI 231 cells. Using recombinant retroviruses with the enhanced green fluorescent protein as selection marker we transduced WEHI 231 cells with chimeric molecules consisting of the extracellular and transmembrane region of human CD40 or rat CD4 and selected portions of the murine CD40 tail. Chimeric molecules with cytoplasmic fragments encompassing the "CD40 tumor necrosis factor-associated factor family member interacting motif" (TIM) were able to sustain growth and to uphold NF-kappaB activity as efficiently as the whole intracellular region of CD40. While the potential of the motif relative to the whole cytoplasmic tail was independent of the heterologous part of the chimeras it was strongly influenced by its distance to the membrane. Placing the 17-amino acid stretch of the motif too close to the membrane, i. e. only two or four amino acids apart, destroyed its capacity to mitigate the anti-IgM effect. Activation of SAPK through the chimeric molecules always correlated with their ability to activate NF-kappaB activity and to rescue the cells from apoptosis induced by antigen receptor ligation. Our data indicate that CD40-TIM carries most if not all of the information needed to deliver the signals responsible for sustaining growth in anti-IgM-stimulated WEHI 231 cells.

Animals↗
PubMed1995

The sensitivity of surface waters of Great Britain to acidification predicted from catchment characteristics.

Using a combination of soil, land use and geological information, a map of Great Britain has been derived which indicates the sensitivity of surface waters to acidification. For the geological information, a slightly modified version of an available map was used which indicated the sensitivity of groundwaters to acidification. For soils, 1-km databases of soil information for England and Wales and for Scotland were employed to map the soil sensitivity as determined by buffering capacity. The derived soils map was modified to take account of agricultural liming in arable and managed grassland areas using the ITE Land Classification. The final map of surface water sensitivity was obtained by using a geographic information system overlay procedure which enabled each combination of soil and geology sensitivity to be uniquely defined. The final sensitivity classification was based upon expert knowledge and the experience of a similar sensitivity mapping exercise for Wales.

Journal Article↗
PubMed1995

An empirical map of critical loads of acidity for soils in Great Britain.

The method used to produce a critical load map of acidity for soils in Great Britain is described. Critical loads were assigned to the dominant soil in each 1 km grid square of the UK national grid. Mineral soils were assigned a critical load based on mineralogy and chemistry, using approaches appropriate to UK conditions. Critical loads for peat soils are based primarily on a maximum acceptable reduction of peat pH, and results from laboratory equilibration studies. The map shows that soils with small critical loads (<0.5 kmol(c) ha(-1) year(-1)) i.e. highly sensitive to acidic deposition, dominate in the north and west of Britain; the south and east are dominated by soils with large critical loads, with small areas of more sensitive soils associated with sandy soil-forming materials. A modified critical load map illustrates the potential impact of agricultural liming on soil critical loads.

Journal Article↗
PubMed1994

Procoagulant activity of PPD-stimulated human lymphocytes after cryopreservation.

OBJECTIVE: Human mononuclear cells from a previously sensitized donor generate procoagulant activity (PCA) following stimulation with purified protein derivative (PPD). Lymphocytes of tuberculous pleural effusions are also highly responsive to PPD stimulation. We examined the influence of cryopreservation on lymphocytes following stimulation with PPD. DESIGN: Peripheral blood lymphocytes of 5 healthy PPD skin test positive subjects were incubated with either PPD, thromboplastin, or concanavalin A (Con A) at concentrations of 0, 1, and 10 micrograms/ml. PCA was determined by measuring the recalcification time. Tests were repeated following cryopreservation for 4 weeks. RESULTS: Incubation of fresh lymphocytes led to a dose dependent shortening of recalcification time: PPD (0-1-10 micrograms/ml: 100-84-65%), thromboplastin (0-1-10 micrograms/ml: 100-85-62%), and Con A (0-1-10 micrograms/ml: 100-85-42%). These results were highly reproducible when tests were repeated 6 weeks later. Cryopreservation did not significantly affect the expression of PCA following incubation with PPD and with thromboplastin. In contrast, cryopreservation significantly diminished the degree of Con A generated PCA. CONCLUSION: Cryopreservation and storage of human lymphocytes is possible without alteration of PCA expression following their incubation with PPD or thromboplastin.

Blood Coagulation Factors↗
PubMed1993

Inhibition of receptor-mediated platelet activation by nedocromil sodium.

BACKGROUND: Platelet activation by platelet activating factor (PAF) seems to be involved in the inflammatory process in asthma and may serve as a possible target for the antiinflammatory drug nedocromil sodium, which is known to inhibit cell activation by different stimuli. METHODS: We investigated the effect and the mode of action of nedocromil sodium on platelet activation by PAF. In a set of healthy volunteers (n = 45) we investigated seven different parameters of platelet activation by PAF, thrombin, and Ca(2+)-ionophore. RESULTS: Nedocromil sodium inhibited: (1) PAF-induced "shape change" reaction up to 78% (50% inhibitory concentration [IC50]: 3 x 10(-9) mol/L), thrombin-mediated "shape change" up to 80% (IC50 2 x 10(-8) mol/L), but not the Ca(2+)-ionophore-dependent reaction, (2) platelet aggregation by PAF up to 85% (IC50 2 x 10(-9) mol/L); (3) release of thromboxane B2 up to 82% (IC50 5 x 10(-9) mol/L); (4) formation of inositol 1,4,5-triphosphate by PAF (IC50 3 x 10(-7) mol/L), by thrombin (IC50 1 x 10(-7) mol/L), but not by Ca2+ ionophore; (5) increase of intracellular free calcium (IC50 4 x 10(-7) mol/L); (6) formation of diacylglycerol (IC50 9 x 10(-9) mol/L), and (7) translocation of protein kinase C (IC50 1 x 10(-7) mol/L). CONCLUSIONS: In the concentration range of the IC50 values found in these experiments, nedocromil sodium reduced PAF binding to platelets by only 10% to 20%, such that this interference cannot explain the observed effects of the compound. Inhibition of receptor-mediated platelet activation at an early stage in the signal transduction pathway, and without effect on Ca(2+)-ionophore-induced platelet activation, suggests an action of nedocromil sodium at the level of the cell membrane.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1993

[Ropivacaine 1% versus bupivacaine 0.75% without a vasoconstrictor. A comparative study of epidural anesthesia in orthopedic surgery].

The long-acting local anaesthetic agent ropivacaine, S(-)-1-propyl-2',6'-pipecoloxylidid, is characterised by lower lipid solubility and lower cardiotoxicity compared with bupivacaine. This study was designed to evaluate its clinical efficacy and motor blocking properties when using lower volumes and higher concentrations of both plain substances. METHODS. In a randomised, double-blind study plain ropivacaine (ro) 1% (150 mg) and bupivacaine (bu) 0.75% (112.5 mg) were compared in 44 patients. In the lateral position, epidural anaesthesia was performed at L2/3 or L3/4 using the loss-of-resistance technique. A test dose of 3 ml was given followed by 12 ml (total volume 15 ml). Sensory blockade was registered by the pin-prick method after 2 min at 5-min intervals up to maximal levels and after the operation at 30-min intervals. Simultaneously, the motor block was determined by means of the Bromage scale. Results are given as median values. RESULTS. The onset of analgesia was 6.0 min for both substances (L2), the time to level L5 16.0 and 17.0 min, respectively. The median maximum upper level of sensory analgesia was achieved after 24.5 min with ro (Th 5) and after 21.0 min (Th 7) with bu. The maximum durations (regression to L2) were 321.5 (ro) and 266.0 min (bu) (P < 0.05). Times for 2-segment regression were comparable at 177.5 and 176.0 min, respectively, and for 4-segment regression at 201.3 and 222.0 min. Twenty-one of the 22 patients developed a first-degree motor block (latency 15 and 12 min); 16 patients in the ro group developed a second-degree block, as did 14 in the bu group (latency 24 and 22 min). Third-degree motor block was recorded in 3 patients (latency 45 and 38 min). The duration of first-degree motor block was 233 min and 207 min, of second-degree block 150 and 155 min, and third-degree block 135 min in both groups. The mean arterial pressures and heart rates did not differ. The diastolic pressures were lower after bu (-8.3%) than after ro (-0.4%) at 30 min. No major side effects were observed. Theodrenaline and/or dihydroergotamine (1:10 diluted) was administered to 38.6% of the patients; 34.1% received atropine for the treatment of bradycardias (decrease > or = 12%) and hypotension of more than 20%. No significant differences were found in frequency of analgesia (pin-prick) between both groups. One of 22 patients in the ro group and 6 of 22 in the bu group required additional analgesics or general anaesthesia. The difference is not statistically significant, but is of clinical relevance. With 2 patients after ro and 4 patients after bu the relaxation was insufficient for good operating conditions. CONCLUSION. Ropivacaine 1% produced a longer duration of analgesia and better clinical efficacy than bupivacaine 0.75%. The clinical difference in motor blockade was not statistically significant. The Bromage scale is not representative for a substance with good analgesic effects and moderate motor blocking properties, as has been shown in sophisticated studies on ropivacaine motor blockade.

Adolescent↗
PubMed1992

Cell cultures from cryopreserved human lung tissue.

To assess gene induction in primary human fibroblasts, we have developed a method for cryopreservation of lung biopsies in liquid nitrogen. Fresh biopsies (n = 10) were chopped into 5 x 5 mm pieces and transferred into an ice-cold freezing medium. Biopsies were kept on ice for 15 min, followed by further cooling of the tissue to -70 degrees C. With this method, lung biopsies were preserved for more than 1 year before they were used for generating cell cultures. There was no significant difference in the biological responsiveness of fibroblasts generated from immediately cultured lung biopsies compared with those from cryopreserved tissue. The doubling rate of fibroblasts from fresh tissue was 23.6 +/- 1.1 hr; compared to 23.5 +/- 1.5 hr for fibroblasts generated from cryopreserved tissue. PDGF-BB enhanced de novo synthesis of DNA 100 times, in both the immediately cultured fibroblasts and those generated from cryopreserved biopsies. Macrophages, dendritic cells and endothelial cells could also be recovered from cryopreserved lung tissue. This method permits long-term storage of lung tissue and the possibility of establishing primary cell lines from the same tissue at later times without appreciable changes in their cellular biological characteristics.

Cell Cycle↗
PubMed1992

An application and review of the critical load concept to the soils of northern England.

In common with other member states of UN-ECE, maps of critical loads of transboundary air pollutants are to be produced in the UK for different receptor (waters, soils and vegetation) types. These maps will be used as a tool for assessing different deposition scenarios with proposed pollution abatement strategies. This paper presents the methodology, results and a discussion of the principles used in applying critical loads of sulphur as a pilot study for soils in northern England. For the study area, critical load classes for soils vary with geology, drift cover and slope/elevation. The area of soils in which the critical load is exceeded varies significantly according to the type of deposition data utilised.

Journal Article↗
PubMed1988

[Follow-up of infected patients in an intensive care unit using the "infection score," endotoxin and AT III determination].

74 patients treated in the intensive care unit for postoperative sepsis were prospectively documented. The severity of sepsis was monitored by a scoring system. Additionally, daily measurements of antithrombin III (AT-III) levels, thrombocytes and endotoxin plasma concentrations were performed. The sepsis score only discriminated between surviving and non-surviving patients. The sensitivity in predicting death due to sepsis was 94%, the specificity 80% in case that a sepsis score of 19 was achieved. In contrast, thrombocytes, endotoxin plasma concentrations and AT-III levels were not able to predict the final outcome, but could be correlated to the severity of sepsis. Since high score levels can also be caused by multiple organ failure due to other reasons, the septic condition of the patients should be defined in the future by the combination of this scoring system with the endotoxin or AT-III measurement.

Adolescent↗