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Biomedical subjects

D Hofmann

Publications and source records attributed to D Hofmann.

At least 19 recordsLinked to original sources
PubMed2006

Effectiveness of budesonide nebulising suspension compared to disodium cromoglycate in early childhood asthma.

OBJECTIVE: The optimal treatment for early childhood asthma remains controversial. Budesonide (BUD) has shown superiority over placebo in infants, and over disodium cromoglycate (DSCG) in children aged > 2 years. The aim of this double-blind, randomised, parallel-group study was to compare the effectiveness of nebulised BUD and DSCG in asthmatic children aged < 36 months. RESEARCH DESIGN AND METHODS: 82 infants (mean age 18.0 months [range, 11.6-31.2 months]) with suspected asthma (three exacerbations of dyspnoea and wheezing during the past 12 months, with one or more exacerbations in the past 3 months) were treated for 3 months with nebulised BUD (Pulmicort Respules) 0.5 mg/2 mL bid or DSCG 20 mg/2 mL tid. Follow-up was at 6 months. MAIN OUTCOME MEASURES AND RESULTS: Patients treated with BUD had a lower exacerbation rate than DSCG-treated patients after 3 months of treatment (5.4% vs. 31.7%; p = 0.003) and towards the end of follow-up (30% vs. 49%; p = 0.062). During treatment, days without cough were 80% and 65% for BUD and DSCG, respectively (p = 0.014), and nights without cough were 89% and 78%, respectively (p = 0.016). Side-effects were mild and of similar frequency in both groups. CONCLUSIONS: Inhaled nebulised BUD was well tolerated and more effective than nebulised DSCG in reducing the incidence of asthma exacerbations and days with symptoms. These beneficial effects of BUD were maintained throughout the 6-month follow-up.

Anti-Asthmatic Agents↗
PubMed2005

[Extended hemodynamic monitoring using transpulmonary thermodilution Influence of various factors on the accuracy of the estimation of intrathoracic blood volume and extravascular lung water in critically ill patients].

BACKGROUND: The transpulmonary thermal-dye dilution (TDD) is the clinical gold standard for measurement of intrathoracic blood volume (ITBV) and extravascular lung water (EVLW). Recently, experimental and clinical studies found that ITBV and EVLW can be derived reliably by single transpulmonary thermodilution (TD), however, dependency from various factors of lung function has been discussed. PATIENTS AND METHODS: We retrospectively analyzed data from 174 critically ill patients who had undergone hemodynamic monitoring by TDD. We calculated the differences of simultaneous TD and TDD determined by ITBV or EVLW measurements. Bias and standard deviations (SD) were calculated and extended Bland-Altman regression analyses were performed. Association of the differences and the potential confounders gender, age, PEEP, p(a)O(2)/F(I)O(2) ratio and the corresponding TDD measurement were analyzed by multiple linear regression and LOWESS regression. RESULTS: Overall results (bias+/-SD) were 1+/-58 ml/m(2) for ITBV and 0.0+/-1.4 ml/kg bw for EVLW, but TD overestimated TDD results in patients with higher ITBV and underestimated those for lower ITBV values. The deviations were small, and the dependence of ITBV could be explained completely by dependence on PEEP and age. However, low values of EVLW are overestimated by TD. CONCLUSION: Single transpulmonary thermodilution for estimation of ITBV or EVLW is reliable in patients with severe lung injury for normal and higher values.

Adolescent↗
PubMed2005

Increasing cardiac output by fluid loading: effects on indocyanine green plasma disappearance rate and splanchnic microcirculation.

BACKGROUND: Sufficient cardiac pre-load for maintaining adequate cardiac output is a major goal in the treatment of critically ill patients. We studied the effects of increasing cardiac output by fluid loading on the indocyanine green plasma disappearance rate (ICG-PDR) and gastric mucosal regional CO2 tension (PRco2) as an indicator of splanchnic microcirculation. METHODS: With approval by our ethics committee and written consent, we studied post-operatively 12 patients (1 female, 11 males; 66 +/- 13 years) with elective coronary artery bypass grafting (n = 10) or aortic valve replacement (n = 2). All patients had received pulmonary artery and left atrial catheterization previously for clinical indications. Cardiac output and filling pressures were measured immediately after intensive care unit (ICU) admission and 1 h after the beginning of fluid loading. RESULTS: Overall, 630 +/- 130 ml of 6% hydroxyethylstarch (130 kDa) was infused with the splanchnic perfusion pressure remaining constant. Norepinephrine and epinephrine dosages were unchanged. The cardiac index increased significantly from 2.8 +/- 0.7 to 3.5 +/- 0.6 l/min/m2 and the stroke volume index from 30 +/- 7 to 38 +/- 8 ml/m2. ICG-PDR showed no significant change, i.e. from 21.2 +/- 6.5 to 21.6 +/- 6.5%/min. Gastric mucosal PRco2 and the Pco2 gap (difference between regional and end-tidal CO2 tension) were constant, i.e. changed from 5.1 +/- 0.8 to 5.5 +/- 1.1 kPa and from 0.9 +/- 0.5 to 1.0 +/- 0.7 kPa, respectively. CONCLUSION: Increasing cardiac output to supranormal values by fluid loading is not associated with a significant change in ICG-PDR or gastric mucosal PRco2.

APACHE↗
PubMed2004

The distribution of the unoccupied volume in glassy polymers.

The aim of this paper is to present an improved method to describe the unoccupied volume in glassy polymers. The method is able to treat atoms with non-spherical symmetry. The fineness of the raster points scanning the unit cell can be as small as 0.01 nm. This method was used to determine the unoccupied volume of molecular dynamic simulations of poly(amide imide) unit cells by probing it with a tracer atom. Since the reachable unoccupied volume strongly depends on the tracer radius, we used tracer radii between 0.03 and 0.17 nm. The poly(amide imide)s were used in the present work because they are well characterized, especially there already exist free volume data determined by positron lifetime experiments.

Computer Simulation↗
PubMed2003

Efficacy of dry extract of ivy leaves in children with bronchial asthma--a review of randomized controlled trials.

OBJECTIVES: To investigate if extracts from dried ivy leaves (Hedera helix L.) are effective in the treatment of chronic airway obstruction in children suffering from bronchial asthma. DESIGN: Systematic review of trials documented in the literature with re-analysis of original data. TRIALS: 5 randomized controlled trials investigating the efficacy of ivy leaf extract preparations in chronic bronchitis, 3 of which were conducted in children and met our selection criteria. One compared ivy leaf extract cough drops to placebo, one compared suppositories to drops and one tested syrup against drops. MAIN OUTCOME MEASURES: Body-plethysmographic and spirometric measures. RESULTS: Drops were significantly superior to placebo in reducing airway resistance (primary outcome measure; p = 0.04 two-sided) and descriptively superior in all other 'objective' measures. For syrup and suppositories, at least 54%, resp. 35% of the effect against placebo were preserved. CONCLUSIONS: The trials included in this review indicate that ivy leaf extract preparations have effects with respect to an improvement of respiratory functions of children with chronic bronchial asthma, but more far-reaching conclusions can hardly be drawn because of a meagre database, including the fact that only one primary trial included a placebo control. Further research, particularly into the long-term efficacy of the herbal extract, is needed.

Asthma↗
PubMed2003

Sample preparation techniques for the determination of natural 15N/14N variations in amino acids by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS).

In order to identify natural nitrogen isotope variations of biologically important amino acids four derivatization reactions (t-butylmethylsilylation, esterification with subsequent trifluoroacetylation, acetylation and pivaloylation) were tested with standard mixtures of 17 proteinogenic amino acids and plant (moss) samples using GC-C-IRMS. The possible fractionation of the nitrogen isotopes, caused for instance by the formation of multiple reaction products, was investigated. For biological samples, the esterification of the amino acids with subsequent trifluoroacetylation is recommended for nitrogen isotope ratio analysis. A sample preparation technique is described for the isotope ratio mass spectrometric analysis of amino acids from the non-protein (NPN) fraction of terrestrial moss. 14N/15N ratios from moss (Scleropodium spec.) samples from different anthropogenically polluted areas were studied with respect to ecotoxicologal bioindication.

Amino Acids↗
PubMed2001

Effects of dexamethasone on proliferation, chemotaxis, collagen I, and fibronectin-metabolism of human fetal lung fibroblasts.

Premature infants at risk for bronchopulmonary dysplasia (BPD) are often treated with dexamethasone (Dex), which has been shown to suppress inflammatory processes in the lung. To elucidate a possible direct influence on the fibroproliferative component of the disease, we studied the effects of Dex in therapeutic and supratherapeutic dosages (5-50 nmol/L) on proliferation, chemotaxis, procollagen I, and fibronectin metabolism of human fetal lung fibroblasts in vitro. Proliferation was inhibited by Dex in a dose-dependent manner. Chemotactic activity in response to conditioned medium of human fetal fibroblasts also showed a dose-dependent inhibition after pretreatment with Dex. The amount of procollagen I C-terminal propeptide and fibronectin per cell in the cell culture supernatant was increased in the presence of Dex. Our results show that Dex does not uniformly suppress the fibroproliferative activity of human fetal lung fibroblasts, which may explain in part the unsatisfactory long-term effects of Dex treatment in BPD.

Anti-Inflammatory Agents↗
PubMed2001

Persistent organochlorine pesticides detected in blood and tissue samples of vultures from different localities in South Africa.

Gas chromatography was used to establish the presence of quantifiable residues of 14 persistent chlorinated hydrocarbon pollutants in whole blood, clotted blood, heart, kidney, liver and muscle samples obtained from individual African whitebacked (Pseudogyps africanus), Cape griffon (Gyps coprotheres) and Lappetfaced (Torgos tracheliotos) vultures from different localities in South Africa. The levels of pesticides measured in whole blood samples of live specimens were compared between nestlings from two natural breeding colonies, adults from a wildlife area and birds held in captivity. Statistically significant (P<0.05) differences between populations were detected in geometric means calculated for gamma-BHC (lindane), alpha(cis)-chlordane and alpha-endosulfan. Five of the organochlorine contaminants displayed significant variations between concentrations detected in the clotted blood, organs and muscles excised from vulture carcasses. This includes residues of gamma-BHC, alpha-chlordane, dieldrin, beta-endosulfan and heptachlor epoxide. Values of the respective biocides measured in vulture samples were generally low in comparison to results documented for a number of avian species. Although no threat is posed by any of the organochloride pesticides, continual monitoring of especially breeding colonies is recommended. Furthermore, the suitability of African whitebacked vulture nestlings as basic bioindicators is highly advocated.

Chlordan↗
PubMed2001

Nitrogen isotope ratios in pine bark as an indicator of N emissions from anthropogenic sources.

The article describes the use of Scots pine bark to identify nitrogen sources in eastern Germany, as well as background areas in Russia and Bulgaria, by using natural isotope ratios of total nitrogen (Nt) and individual N compounds such as ammonium (NH4+), nitrate (NO3-) and amid nitrogen (amide-N). The samples collected were analysed using an elemental analyser in connection with a gas isotope mass spectrometer (EA-IRMS). Natural 15N abundances in pine bark from impact areas suggest that the ammonium accumulated on the surface of the bark is released from livestock management. Bark of Scots pines growing near agricultural land had highly depleted delta15Nt values (between -8 and -12 one thousand percent), while bark from background areas (unpolluted areas) displayed slightly negative delta15Nt values (mean 15Nt = -3.8 one thousand percent). It is assumed that part of the N adsorbed on the bark surface is mainly derived from ammonia (mean 15Nt = -40.3 one thousand percent) escaping from livestock housing and during the application of manure. This assumption is confirmed by experiments under controlled conditions in which manure samples were spread on soil. In addition, temporal and spatial variations of 15Nt abundances in pine bark from various locations in eastern Germany as well as pine stands in Nature Park Dübener Heath are discussed.

Agriculture↗
PubMed2001

Three cases of C-ANCA-positive vasculitis treated with immunoadsorption: possible benefit in early treatment.

Wegener's granulomatosis is a vasculitic disease predominantly affecting the upper respiratory tract, lungs, and kidneys. Three patients with Wegener's granulomatosis and rapidly progressive glomerulonephritis were treated with an intensified regimen of immunoadsorption (IA) (Excorim or Therasorb) in addition to cyclophosphamide (CYC) and methylprednisolone (PRE). Patient A had been in remission under oral CYC/PRE. The first exacerbation was treated successfully with 4 IA treatments without changing medication. Patient B experienced 3 flares within 1 year, which were treated with 28 IA (3-7 IAs/course), intravenous CYC after each course, and PRE. A fall of creatinine levels from 120 to 190 micromol/L to 100 micromol/L was noted after IA and before administration of CYC. Patient C presented in uremia. Autoantibodies were eliminated by 11 IA treatments parallel to CYC/PRE therapy. They remained within a normal range for >1 year's follow-up; however, kidney function did not return. In conclusion, the observations in Patients A and B suggest a beneficial therapeutic effect of early IA in WG.

Adult↗
PubMed2001

Effect of levosimendan on myocardial contractility, coronary and peripheral blood flow, and arrhythmias during coronary artery ligation and reperfusion in the in vivo pig model.

OBJECTIVE: To determine whether levosimendan, a calcium sensitiser that facilitates the activation of the contractile apparatus by calcium, improves myocardial contractile function during severe ischaemia and reperfusion without exacerbating the incidence of arrhythmias. DESIGN: Pigs were pretreated orally twice daily for 10 days with 0.08 mg/kg levosimendan or placebo. On day 11 the left main coronary artery was ligated for 30 minutes, followed by 30 minutes of reperfusion. A bolus dose of levosimendan, 11.2 microg/kg intravenously, or placebo was given 30 minutes before coronary ligation, followed by a continuous infusion of 0.2 microg/kg/min levosimendan or placebo for the remainder of the experiment. RESULTS: During the ischaemic period, cardiac output was higher in the levosimendan group than in the placebo group (mean (SD): 2.6 (0.5) v 2.0 (0.2) l/min, p < 0.05) and systemic vascular resistance was lower (2024 (188) v 2669 (424) dyne.s(-1).cm(-5), p < 0.005). During reperfusion, cardiac output and contractility (LV(max)dP/dt (pos), 956 (118) v 784 (130) mm Hg/s, p < 0.05) were increased by levosimendan. The incidence of ischaemic ventricular fibrillation and tachycardia was similar in the two groups but there were more arrhythmic events (ventricular tachycardia and ventricular fibrillation) in the levosimendan treated group (8/12 levosimendan v 1/9 control p = 0.05). CONCLUSIONS: Levosimendan improved cardiac output and myocardial contractility during coronary artery ligation and reperfusion. However, it increased the number of arrhythmic events during ischaemia in this model of in vivo regional ischaemia.

Animals↗
PubMed2000

Erythropoietin gene expression in different areas of the developing human central nervous system.

UNLABELLED: Evidence from cell culture and animal experiments suggests a neuroprotective and neurotrophic function of erythropoietin (EPO). We have quantitated the distribution of EPO mRNA expression in the developing human central nervous system (CNS). PATIENTS AND METHODS: Up to seven biopsies from different areas of the CNS of four preterm fetuses (gestational age 23-37 weeks) were obtained at routine postmortem examinations. EPO mRNA was quantitated by competitive PCR in samples from the CNS, the kidneys, and the liver where the EPO gene is predominantly expressed at this gestational age. RESULTS: EPO mRNA was most abundant in one sample from the cerebellum (0.29 amol/microg total RNA [amol=10(-18)mol]) and two from the pituitary gland (0.23 amol/microg total RNA), but levels varied considerably. EPO mRNA in the cortex cerebri (median 0.12 amol/microg total RNA; n=4) dominated over the expression in the corpora amygdala (median 0.05 amol/microg total RNA; n=4), the hippocampus (median 0.03 amol/microg total RNA; n=4), or the basal ganglia (median 0.01 amol/microg total RNA; n=3). Only little EPO mRNA (<0.01 and 0.06 amol/microg total RNA) was found in the spinal cord. EPO mRNA levels in the cerebellum, pituitary gland, or the cerebral cortex were within the same range as in the liver (0.03-1.67 amol/microg total RNA; n=4), or the kidneys (0.06-0.79 amol/microg total RNA; n=4). CONCLUSION: We found the EPO gene expressed throughout the fetal human CNS. Our data provide the basis to discuss a function for EPO in the brain of humans as well.

Central Nervous System↗
PubMed2000

[Aberrations of chromosome 18 and their significance in genetic counseling].

In order to get information on the origin of chromosome 18 aberrations trisomy 18 cases were analysed as well as different chromosome 18 rearrangements. In total, their study population consisted of 100 trisomy 18 patients and their parents, 67 out of which have already been published. Additionally, seven families were analysed with structural aberrations of chromosome 18 including four patients with tetrasomy 18p. Determination of parent and cell stage of origin was performed by short tandem repeat typing (STR, microsatellites). These investigations revealed that the additional chromosomal material in the majority of the chromosomal 18 aberrations was maternal in origin (97/107). In most of the cases the nondisjunction occurred during maternal meiosis II. This was in agreement with findings of other groups. Thus, independently from the type of aberration, there was a predisposition of chromosome 18 for nondisjunction in maternal meiosis II. In this respect, chromosome 18 seemed to be unique among human autosomes. Furthermore, these results showed that molecular genetic analyses of chromosomal aberrations and their formation mechanisms were meaningful tools in genetic counselling situations: in 5 cases where cytogenetic investigations could not performed, the clinical diagnosis of Edwards syndrome could be confirmed by molecular findings. Thus, in these cases other genetic diseases with differing types of inheritance could be excluded from being the cause of the observed malformations. In a further structural rearrangement of chromosome 18, the origin could be determined as being mitotic, therefore a recurrence risk could be excluded for this couple.

Chromosome Aberrations↗
PubMed2000

Pulmonary complications after bone marrow transplantation in children: twenty-four years of experience in a single pediatric center.

In children, pulmonary sequelae contribute to early and late morbidity after bone marrow transplantation (BMT). Between 1975-1999, we performed 152 BMTs in 138 pediatric patients with malignant and nonmalignant diseases. Allogenic bone marrow was used from 99 HLA identical siblings and from 23 other related or unrelated donors. Autologous marrow was used in 30 transplantations. Median age was 8. 6 years (range, 1.1-22.4) at time of BMT. The median survival was 42%, the survival time was 6.5 years (range, 0.8-23.1), and the median follow-up time was 6.8 years (range, 0.8-23.2). Seventeen patients had severe respiratory complications. Early severe respiratory complications leading to death within the first 4 months after BMT were due to pulmonary edema (n = 1), or fungal (n = 3), bacterial (n = 1), or viral (n = 2) pneumonia. Late severe respiratory sequelae were defined as persistent respiratory symptoms for more than 4 months despite treatment, and these occurred in 10 patients, of whom 5 died. Underlying diagnoses covered a wide spectrum, including bronchiolitis obliterans (n = 3), severe restrictive lung disease (n = 2), idiopathic pneumonia syndrome (n = 3), chronic bronchitis (n = 1), and hepatopulmonary syndrome (n = 1). The overall probability for death was 0.58, and for death from severe respiratory complications, 0.16. With improved HLA matching, fewer BMTs after relapsed or primary progressive disease, and improved supportive care, including the usage of CMV negative blood products, after 1990 the probability of death from severe respiratory complications was only 0.04, whereas before 1990 it was 0.23 (P = 0.029; in each time period, n = 69). The disease spectrum has changed from initially more infectious complications to bronchiolitis obliterans and idiopathic pneumonia syndrome. Lung function measurements performed in 85 of 138 patients usually showed a mild restrictive pattern. To identify those children as early as possible who are at risk for severe respiratory complications, a close longitudinal follow-up after BMT by pediatric pulmonologists is necessary.

Adolescent↗
PubMed2000

Removal of immunoglobulins by a protein A versus an antihuman immunoglobulin G-based system: evaluation of 602 sessions of extracorporeal immunoadsorption.

Elimination of IgG can be achieved by extracorporeal immunoadsorption (IA) based on specific binding to either staphylococcal protein A (Excorim) or sheep polyclonal antibodies directed against human IgG (Therasorb). In 602 analyzed sessions of IA, elimination of IgG was 60% through 80% depending on the treated plasma volume, with no significant difference between the mentioned systems. However, the decrease of IgM and IgA was approximately 50% in the anti-IgG compared to 20-40% in the protein A system. Plasma albumin concentration decreased by 20% in the anti-IgG system compared to 15% in the protein A system, and hemoglobin values increased by 2% in the anti-IgG system and decreased by 6% in the protein A system. In conclusion, a clinical relevance for these findings cannot be ruled out, and the individual choice might depend on the clinical situation and laboratory findings.

Antibodies, Anti-Idiotypic↗
PubMed2000

Particle release in extracorporeal low-density lipoprotein lowering therapies.

Release of microparticles into the blood during extracorporeal circulation must be kept low because of possibly serious acute and chronic adverse effects. Concentration and size distribution of microparticles were measured during simulated treatments (n = 7) on original equipment for 2 standard low-density lipoprotein (LDL) elimination procedures (DALI 750, Fresenius AG, St. Wendel, Germany and Liposorber, Kaneka Corporation, Osaka, Japan) and compared to hemofiltration solutions. For both systems as well as in hemofiltration solutions, the mean particle concentrations in 500 ml portions gathered from the efferent blood line stayed below 10% of pharmacopoeia standards for infusion solutions (United States Pharmacopoeia, European Pharmacopoeia) in all measured size classes. Although particle concentrations were comparable in all systems, the mean total number of particles > or =2 microm released per session was lowest in the DALI (167,000) compared to the Liposorber (465,000) and hemofiltration solutions (2,240,000). This was mainly due to different total processed blood volumes necessary to achieve the required LDL reduction.

Adsorption↗
PubMed2000

Immunogenicity and tolerance of a 7-valent pneumococcal conjugate vaccine in nonresponders to the 23-valent pneumococcal vaccine.

There is still a lack of effective vaccination strategies for patients with a deficient antibody response to bacterial polysaccharide antigens. In an open trial, we evaluated the immunogenicity and tolerance of a new 7-valent pneumococcal conjugate vaccine in 22 infection-prone nonresponders to pneumococcal polysaccharide vaccine and 21 controls. In the patient group, nonresponsiveness was confirmed by repeated vaccination with a 23-valent pneumococcal polysaccharide vaccine. The study protocol provided two doses of the pneumococcal conjugate vaccine, given 4 to 6 weeks apart, for both groups. The antibody response was determined before each vaccination and on follow-up by an enzyme-linked immunosorbent assay and compared to the response in a functional opsonophagocytosis assay. Patients showed a significantly lower postvaccination immune response for all serotypes than did controls. The postvaccination response was serotype dependent. A median titer of >1 microgram/ml in patients was recorded only for serotypes 4, 9V, 14, and 19F, which are known to be more immunogenic than serotypes 6B, 18C, and 23F. In the patient group, 70% responded to serotype 19F (Pnc 19F), 65% responded to Pnc 14 and 4, 60% responded to Pnc 9V, 55% responded to Pnc 18C, 50% responded to Pnc 23F, and 25% responded to Pnc 6B. In the control group >95% of individuals showed a titer of >1 microgram/ml to every serotype. The vaccine was tolerated well, and no major side effects have been reported. The new pneumococcal conjugate vaccine is clearly more immunogenic in previous nonresponders than is the 23-valent pneumococcal vaccine. Immunization with a pneumococcal conjugate vaccine should be considered as a strategy to protect high-risk patients.

Adolescent↗