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Biomedical subjects

B Hartmann

Publications and source records attributed to B Hartmann.

At least 55 records · Page 3Linked to original sources
PubMed2002

Short-term administration of glucagon-like peptide-2. Effects on bone mineral density and markers of bone turnover in short-bowel patients with no colon.

BACKGROUND: Glucagon-like peptide 2 (GLP-2) is a newly discovered intestinotrophic hormone. We have recently reported that a 5-week GLP-2 treatment improved the intestinal absorptive capacity of short-bowel patients with no colon. Additionally, GLP-2 treatment was associated with changes in body composition that included a significant increase in total body bone mass. This article describes the effect of GLP-2 on spinal and hip bone mineral density (BMD) and biochemical markers of bone turnover in these patients. METHODS: In an open-labelled pilot study, eight short-bowel patients (3M, 5F; mean age 49 years) with small-bowel resection and no colon received 400 microg s.c. of GLP-2 twice daily for 5 weeks. Four received home parenteral nutrition (mean length of residual jejunum 83 cm) and 4 did not (mean length of ileum resected 106 cm). The outcome measures were the mean percent change from baseline in spinal and hip BMD measured by dual-energy X-ray absorptiometry, changes in four biochemical markers of bone-turnover, PTH, 25-hydroxy vitamin-D, and the intestinal absorption of calcium. RESULTS: Mean +/- s(x) (SEM) percent changes in spinal and hip BMD were 1.1+/-0.4% (P < 0.05) and 1.9+/-0.8% (P = 0.06), respectively. The intestinal calcium absorption increased by 2.7% (P = 0.87). Serum ionized calcium increased in 5/8 patients with a concomitant decrease in serum PTH values. Three of the four markers of bone turnover decreased. CONCLUSION: A 5-week GLP-2 administration significantly increased spinal BMD in short-bowel patients with no colon. The mechanism by which GLP-2 affects bone metabolism remains unclear, but may be related to an increased mineralization of bone resulting from an improved intestinal calcium absorption.

Absorptiometry, Photon↗
PubMed2001

Identification of candidate downstream genes for the homeodomain transcription factor Labial in Drosophila through oligonucleotide-array transcript imaging.

BACKGROUND: Homeotic genes are key developmental regulators that are highly conserved throughout evolution. Their encoded homeoproteins function as transcription factors to control a wide range of developmental processes. Although much is known about homeodomain-DNA interactions, only a small number of genes acting downstream of homeoproteins have been identified. Here we use a functional genomic approach to identify candidate target genes of the Drosophila homeodomain transcription factor Labial. RESULTS: High-density oligonucleotide arrays with probe sets representing 1,513 identified and sequenced genes were used to analyze differential gene expression following labial overexpression in Drosophila embryos. We find significant expression level changes for 96 genes belonging to all functional classes represented on the array. In accordance with our experimental procedure, we expect that these genes are either direct or indirect targets of labial gene action. Among these genes, 48 were upregulated and 48 were downregulated following labial overexpression. This corresponds to 6.3% of the genes represented on the array. For a selection of these genes, we show that the data obtained with the oligonucleotide arrays are consistent with data obtained using quantitative RT-PCR. CONCLUSIONS: Our results identify a number of novel candidate downstream target genes for Labial, suggesting that this homeoprotein differentially regulates a limited and distinct set of embryonically expressed Drosophila genes.

Animals↗
PubMed2001

Gravitationally bound monopoles.

We construct monopole solutions in SU(2) Einstein-Yang-Mills-Higgs theory carrying magnetic charge n. For vanishing and small Higgs self-coupling, these multimonopole solutions are gravitationally bound. Their mass per unit charge is lower than the mass of the n = 1 monopole. For large Higgs self-coupling only a repulsive phase exists.

Journal Article↗
PubMed2001

A versatile palladium-mediated three-component reaction for the one-pot synthesis of stereodefined 3-arylidene-(or 3-alkenylidene-)tetrahydrofurans.

A one-pot reaction between equimolecular amounts of various propargyl alcohols, Michael acceptors, and unsaturated halides (or triflates) in the presence of a palladium(0) catalyst provides a simple and flexible entry into highly substituted 3-arylidene-(or 3-alkenylidene-)tetrahydrofurans. The efficiency of this palladium-mediated three-component reaction has been shown to be strongly influenced by the nature of the catalyst system, and in this regard, a palladium(0) catalyst generated in situ by reduction of PdCl2(PPh3)2 with n-butyllithium has been found particularly effective.

Journal Article↗
PubMed2001

Interaction of gap genes in the Drosophila head: tailless regulates expression of empty spiracles in early embryonic patterning and brain development.

Unlike gap genes in the trunk region of Drosophila embryos, gap genes in the head were presumed not to regulate each other's transcription. Here, we show that in tailless (tll) loss-of-function mutants the empty spiracles (ems) expression domain in the head expands, whereas it retracts in tll gain-of-function embryos. We have identified a 304bp element in the ems-enhancer which is sufficient to drive expression in the head and brain and which contains two TLL and two BCD binding sites. Transgenic reporter gene lines containing mutations of the TLL binding sites demonstrate that tll directly inhibits the expression of ems in the early embryonic head and the protocerebral brain anlage. These results are the first demonstration of direct transcriptional regulation between gap genes in the head.

Animals↗
PubMed2001

Evaluation of the suitability of a patient data management system for ICUs on a general ward.

The development of the ICUData patient data management system (PDMS) for intensive care units (ICU), by IMESO GmbH, Hüttenberg, Germany, was based on the assumption that processes and therapies at ICU are the most complex with the highest data density compared with those in other wards. Based on experience with the system and on a survey conducted among users at our pain clinic, we evaluated whether the concept of the present software architecture, which sufficiently reproduces processes and data at an ICU, is suitable as a PDMS for general wards. The highly modular and client-centric approach of the PDMS is founded on a message-based communications architecture (HL7). In the beginning of the year 2000, the system was implemented at the pain management clinic (12 beds) of our hospital. To assess its user friendliness, we conducted a survey of medical staff (n=14). From April 1st 2000 to August 31st 2000, all clinical and administrative data of 658 patients at the pain management clinic were recorded with the PDMS. From the start, all users had access to data and information of other connected data management systems of the hospital (e.g. patient administrative data, patient clinical data). Staff members found the system mostly useful, clearly presented, practical, and easy to learn and use. Users were relatively satisfied with stability and performance of the program but mentioned having only limited knowledge of the program's features. The need for external support during a computer crash was rated negatively. Despite the need for further usage training and improved program performance, the software architecture described seems to be a promising starting point for the construction of a PDMS for general wards.

Attitude of Health Personnel↗
PubMed2001

Intestinal growth adaptation and glucagon-like peptide 2 in rats with ileal--jejunal transposition or small bowel resection.

Glucagon-like peptide 2 (GLP-2), produced by enteroendocrine L-cells, regulates intestinal growth. This study investigates circulating and intestinal GLP-2 levels in conditions with altered L-cell exposure to nutrients. Rats were allocated to the following experimental groups: ileal-jejunal transposition, resection of the proximal or distal half of the small intestine, and appropriate sham-operated controls. After two weeks, ileal-jejunal transposition led to pronounced growth of the transposed segment and also of the remaining intestinal segments. Plasma GLP-2 levels increased twofold, whereas GLP-2 levels in the intestinal segments were unchanged. In resected rats with reduced intestinal capacity, adaptive small bowel growth was more pronounced following proximal resection than distal small bowel resection. Circulating GLP-2 levels increased threefold in proximally resected animals, and twofold in the distally resected group. Tissue GLP-2 levels were unchanged in resected rats. The data indicate that transposition of a distal part of the small intestine, and thereby exposure of L cells to a more nutrient-rich chyme, leads to intestinal growth. The adaptive intestinal growth is associated with increased plasma levels of GLP-2, and GLP-2 seems to act in an endocrine as well as a paracrine manner.

Adaptation, Physiological↗
PubMed2001

Sealing of postoperative axillary leakage after axillary lymphadenectomy using a fibrin glue coated collagen patch: a prospective randomised study.

Seroma formation after axillary lymphadenectomy in women with breast cancer remains a problem despite many efforts to reduce surgery-related morbidity. In a prospective, randomised, open, parallel-group, controlled clinical trial we evaluated the effect of a fibrin-glue coated collagen patch (TachoComb H, Nycomed Pharma AS, Denmark) on volume and duration of postoperative axillary drainage, duration of hospital stay, and procedural safety. Sixty patients were included in the study. Patients did not differ with respect to general characteristics, such as age, body mass index, treatment modality, and tumor stage distribution. In 29 patients, a fibrin-glue coated collagen patch was applied from the apex axillae to the thoracic longus nerve and half a patch was applied to the lateral border of the axillary nerve-vessel bundle. Thirty-one patients were randomised to standard closure of the axillary lymphadenectomy area. The mean duration of axillary drainage was 3.8 +/- 1.9 days in the fibrin-glue treatment group and 3.9 +/- 1.8 days in the control group (p = NS). The mean total drainage volume was 338.5 +/- 251.8 ml in the fibrin-glue treatment group and 370.8 +/- 314.6 ml in the standard closure group (p = NS). The mean length of post-operative hospital stay was 9.1 +/- 2.7 days in the fibrin-glue treatment group and 9.3 +/- 3.6 days in the standard closure group (p = NS). Seven patients (25%) and eight patients (25%) were diagnosed with local inflammation in the fibrin-glue treatment group and the standard closure group, respectively (p = NS). Seroma formation after drain removal was found in 11 patients (39%) in the fibrin-glue treatment group and in 13 patients (42%) in the standard closure group (p = NS). In summary, we observed no statistically significant differences with respect to axillary drainage time, drainage volume, length of hospital stay, local inflammation, and seroma formation after drainage removal.

Axilla↗
PubMed2001

Factors determining length of stay of surgical day-case patients.

BACKGROUND AND OBJECTIVE: Factors which lead to prolonged stay in the day-care unit and unplanned admission after day-case surgery are poorly understood. METHODS: Data sets of 3152 day-case patients were collected with a computerized online record keeping system (NarkoData). Predictors of prolonged postoperative stay including unanticipated admission were identified using univariate analysis. Charts of patients, who needed admission, were reviewed. RESULTS: 13.2% of day-case patients had a postoperative stay < or = 3 h, 55.3% 3-6 h and 26.2% > or = 6 h. The rate of unanticipated admission was 5.4%. Intraoperative haemoglobin concentration and blood loss were the best predictors of a prolonged postoperative stay. Other significant predictors were female gender, advanced age, longer duration of surgery, larger volume of infusions, intubation, spinal anaesthesia, intraoperative use of opioids and non-depolarizing muscle relaxants, high pain score, nausea and vomiting and prolonged preoperative waiting time. Chart review of patients admitted to hospital confirmed the validity of the statistically significant predictors. CONCLUSIONS: In day-case surgery, the predictors of prolonged stay in the day-care unit and unplanned Hospital admission are mainly related to the surgical procedure.

Ambulatory Surgical Procedures↗
PubMed2001

Therapeutic plasma exchange in the intensive care setting.

The potential to treat life-threatening conditions with therapeutic plasma exchange (TPE) is limited to a few situations. In severe pulmonary hemorrhage as a complication of several immune disorders (e.g., antiglomerular basement membrane antibody disease, Wegener's granulomatosus, lupus erythematosus), TPE should only be considered after conventional measures (mostly pulses of methylprednisolone) have been applied. Idiopathic familial and nonfamilial thrombotic thrombocytopenic purpura as well as the subset of the hemolytic uremic syndrome not associated with diarrhea are clear indications for TPE using fresh frozen plasma as replacement fluid. Patients with myasthenic crisis will also benefit from TPE and will improve within 1 day. Acute pancreatitis as a complication of the chylomicronemia syndrome has a poor prognosis and should be treated with TPE without any delay. In the case of drug overdose or intoxication, the efficiency of TPE to remove the offending drug is usually overestimated. In this situation, TPE is useful only when the plasma protein binding of the substance is high (>80%) and the volume of distribution is low (<0.2 L/kg body weight). TPE is not without risks and hazards (e.g., vascular access, bleeding, allergy), which should also be considered when discussing this extracorporeal therapy in otherwise refractory clinical conditions.

Hematologic Diseases↗
PubMed2001

Glucagon-like peptide 2 improves nutrient absorption and nutritional status in short-bowel patients with no colon.

BACKGROUND & AIMS: Glucagon-like peptide 2 (GLP-2) is intestinotrophic, antisecretory, and transit-modulating in rodents, and it is mainly secreted from the intestinal mucosa of the terminal ileum and colon after food ingestion. We assessed the effect of GLP-2 on the gastrointestinal function in patients without a terminal ileum and colon who have functional short-bowel syndrome with severe malabsorption of wet weight (>1.5 kg/day) and energy (>2.3 MJ/day) and no postprandial secretion of GLP-2. METHODS: Balance studies were performed before and after treatment with GLP-2, 400 microg subcutaneously twice a day for 35 days, in 8 patients (4-17 years from last bowel resection; 6 with Crohn's disease). Four patients received home parenteral nutrition (mean residual jejunum, 83 cm), and 4 did not (mean ileum resection, 106 cm). Biopsy specimens were taken from jejunal/ileal stomas, transit was measured by scintigraphy, and body composition was measured by dual-energy x-ray absorptiometry. RESULTS: Treatment with GLP-2 improved the intestinal absorption of energy 3.5% +/- 4.0% (mean +/- SD) from 49.9% to 53.4% (P = 0.04), wet weight 11% +/- 12% from 25% to 36% (P = 0.04), and nitrogen 4.7% +/- 5.4% from 47.4% to 52.1% (P = 0.04). Body weight increased 1.2 +/- 1.0 kg (P = 0.01), lean body mass increased 2.9 +/- 1.9 kg (P = 0.004), fat mass decreased 1.8 +/- 1.3 kg (P = 0.007), and 24-hour urine creatinine excretion increased (P = 0.02). The time to 50% gastric emptying of solids increased 30 +/- 16 minutes from 89 to 119 minutes (P < 0.05). Small bowel transit time was not changed. Crypt depth and villus height were increased in 5 and 6 patients, respectively. CONCLUSIONS: Treatment with GLP-2 improves intestinal absorption and nutritional status in short-bowel patients with impaired postprandial GLP-2 secretion in whom the terminal ileum and the colon have been resected.

Adult↗
PubMed2001

Secretion of trophic gut peptides is not different in bolus- and continuously fed piglets.

In neonates, bolus feeding is associated with greater rates of intestinal growth than is continuous feeding. We tested whether the concentrations and secretion rates of trophic gut peptides are higher in bolus-fed than in continuously fed piglets. Five 21-d-old piglets were surgically implanted with gastric, arterial and portal catheters and a portal blood flow probe. At postnatal d 30 and 31, pigs received an equal amount of primed continuous or bolus feeding of a cow's milk formula in a randomized, crossover design. During a 6-h period, portal blood flow and arterial and portal concentrations of glucagon-like peptide-2 (GLP-2), peptide YY (PYY) and gastric inhibitory polypeptide (GIP) were measured. All hormone levels were significantly increased within 1 h of the start of the experiment, independent of the feeding modality. There were no differences between bolus and continuous feeding in either the arterial concentrations or secretion rates of GLP-2, PYY and GIP. In both treatment groups, the increases in the plasma concentrations of GLP-2 and GIP after feeding were substantially greater than those for PYY. We conclude that the production or circulating concentrations of GLP-2, PYY and GIP are not significantly different in bolus- and primed continuously fed piglets.

Animals↗
PubMed2001

The use of an anesthesia information management system for prediction of antiemetic rescue treatment at the postanesthesia care unit.

UNLABELLED: We used an anesthesia information management system (AIMS) to devise a score for predicting antiemetic rescue treatment as an indicator for postoperative nausea and vomiting (PONV) in the postanesthesia care unit (PACU). Furthermore, we wanted to investigate whether data collected with an AIMS are suitable for comparable clinical investigations. Over a 3-yr period (January 1, 1997, to December 31, 1999), data sets of 27,626 patients who were admitted postoperatively to the PACU were recorded online by using the automated anesthesia record keeping system NarkoData(R) (IMESO GmbH, Hüttenberg, Germany). Ten patient-related, 5 operative, 15 anesthesia-related, and 4 postoperative variables were studied by using forward stepwise logistic regression. Not only can the probability of having PONV in the PACU be estimated from the 3 previously described patient-related (female gender, odds ratio [OR] = 2.45; smoker, OR = 0.53; and age, OR = 0.995) and one operative variables (duration of surgery, OR = 1.005), but 3 anesthesia-related variables (intraoperative use of opioids, OR = 4.18; use of N(2)O, OR = 2.24; and IV anesthesia with propofol, OR = 0.40) are predictive. In implementing an equation for risk calculation into the AIMS, the individual risk of PONV can be calculated automatically. IMPLICATIONS: The aim of this study was to investigate predictors for postoperative nausea and vomiting by using online anesthesia records. With the help of computerized data evaluation, 7 of 34 variables could be detected as risk factors. By implementing an automatic score into the record keeping system, an individual risk calculation could be made possible.

Adult↗
PubMed2001

Potentiation of sildenafil-induced hypotension is minimal with nitrates generating a radical intermediate.

Recently the new specific phosphodiesterase-5 inhibitor sildenafil was introduced into therapy for erectile dysfunction. Because of the phosphodiesterase-5 inhibitor-induced increases of cyclic GMP in the vasculature, vasodilation in various vascular beds is induced, which in combination with various nitrovasodilators (e.g., when used simultaneously for the treatment of coronary artery disease), may lead to excessive hypotension. Thus nitrovasodilators are contraindicated when sildenafil may be used and reports of a number of accidents have recently been published. We therefore studied the acute interactions of glyceryl trinitrate (GTN), pentaerythritol tetranitrate (PETN), and isosorbide dinitrate (ISDN) with sildenafil in six chronically instrumented conscious dogs for each nitrate to assess the magnitude of blood pressure drops (and compensatory increases in heart rate) during a 24-h nitrate administration (infusion into the pulmonary artery). Sildenafil (3 mg/kg) was given orally (after a 24-h fast) 30 min after start of nitrate infusion. GTN, PETN, or ISDN (which follow different steps of metabolic conversion to nitric oxide) were applied at submaximal dosages leading to 90% of maximal coronary artery dilation at 1.5 microg/kg per min, 0.75 microg/kg per min, or 6 microg/kg per min, respectively. During GTN infusion sildenafil caused a maximum drop in mean blood pressure of 21 +/- 3 mm Hg (rise in heart rate from 117.0 +/- 7.2 to 126.0 +/- 6 .0/min) and during ISDN infusion of 18 +/- 3 mm Hg (rise in heart rate from 115.0 +/- 7.0 to 125 +/- 6/min), which was significantly less (p < 0.01) during PETN (only 6 +/- 1 mm Hg with a rise in heart rate from 107.0 +/- 5.0 to 122.0 +/- 7.0/min). When sildenafil is used during exposure to nitrates (e.g., in coronary artery disease), the PETN-induced drop in blood pressure at equi-effective dosages (with regard to coronary dilation) is substantially smaller compared with that of GTN or ISDN, which is probably because of lesser potentiation of phosphodiesterase-5 inhibitor-induced effects in the arteriolar bed, thus minimizing critical drops in blood pressure.

Animals↗
PubMed2001

Time-dependent intestinal adaptation and GLP-2 alterations after small bowel resection in rats.

Existing data on morphological adaptation after small bowel resection are obtained by potentially biased methods. Using stereological techniques, we examined segments of bowel on days 0, 4, 7, 14, and 28 after 80% jejunoileal resection or sham operation in rats and correlated intestinal growth with plasma levels of glucagon-like peptide-2 (GLP-2). In the jejunum and ileum of the resected rats, the mucosal weight increased by 120 and 115% during the first week, and the weight of muscular layer increased by 134 and 83%, compared with sham-operated controls. The luminal surface area increased by 190% in the jejunum and by 155% in the ileum after 28 days. The GLP-2 level was increased by 130% during the entire study period in the resected rats. Small bowel resection caused a pronounced and persistent transmural growth response in the remaining small bowel, with the most prominent growth occurring in the jejunal part. The significantly elevated GLP-2 level is consistent with an important role of GLP-2 in the adaptive response.

Adaptation, Physiological↗