Biomedical subjects

H Moeller

Publications and source records attributed to H Moeller.

At least 19 recordsLinked to original sources

PubMed2005

Effect of 3T MRI on the function of shunt valves--evaluation of Paedi GAV, Dual Switch and proGAV.

The MR-compatibility of medical implants and devices becomes more and more important with the increasing number of high-field MR-scanners employed. Until the end of 2004, about twenty 3T MR in Germany will be in clinical practice. Patients with hydrocephalus need frequent follow-up MR-examinations to assure correct functioning of a shunt. We tested three types of gravitational valves: the Paedi GAV, the Dual Switch and as a new programmable valve the proGAV (Miethke Company, Berlin), that have not been evaluated at 3T, yet. In sum, there is strong evidence for maintenance of function of these valves after exposure to 3T. This also implies the programmable valve, as long as the brake mechanism is properly adjusted during MR-examination.

Cerebrospinal Fluid Shunts↗

PubMed2002

A non-randomised pilot study to compare complementary and conventional treatments of acute sinusitis.

BACKGROUND: It is still under discussion whether antibiotics are effective in the treatment of acute sinusitis. Moreover, they are known to have considerable side-effects. In contrast, complementary approaches are reported to have little side-effects and an equivalent efficiency. OBJECTIVES: To assess the success of conventional and complementary treatments of acute sinusitis and to estimate the patient numbers needed to confirm therapeutic equivalence. Treatment success was measured by three different scores, assessed by both patients and physicians. METHODS: Multicentre (2 complementary and 3 conventional ENT centres), non-randomised, controlled clinical trial with 63 patients (complementary group 30, conventional group 33 patients). To control for confounders treatment differences were estimated by propensity score techniques. TREATMENTS: The choice of medication was entirely left to the physician. We recommended to use antibiotics, secretolytics and symptomimetics in the conventional group and a combination of the herbal remedy Sinupret((R)) and the homeopathic remedy Cinnabaris 3X in the complementary group. RESULTS: Treatment differences varied substantially depending on the outcome measure, but they were always not clinically relevant. Conventional treatment was slightly better when the outcome was assessed by the physicians (1.8 score points) but slightly worse when it was assessed by patients (0.2 score points) or in terms of the HCG-5 quality of life score (0.8 score points). p values were always > 0.3. CONCLUSIONS: Both treatments appear to be equally effective (or ineffective). Results might be biased because both treatment groups differed substantially. Randomised trials including at least 400 patients are needed to produce valid results.

Acute Disease↗

PubMed2002

An example on the value of non-randomisation in clinical trials in complementary medicine.

BACKGROUND: Randomised clinical trials may in principle show a small external validity. Non-randomised clinical trials therefore are sometimes regarded as an appropriate alternative when complementary and conventional treatments are compared. OBJECTIVES: To assess the value of advanced statistical methods in the process of estimating differences between a complementary and a conventional treatment of acute sinusitis in a non-randomised clinical trial. METHODS: Multicentre, non-randomised, controlled clinical trial comparing 2 complementary and 3 conventional ENT centres. Patients were free to choose the physician (and hence the therapy). Treatment differences were estimated by controlling for confounders in analyses of covariance or by propensity score techniques. RESULTS: Most potential confounders (sex, age, life-style parameters) did not have significant effects on the choice of therapy. Disease severity and previous ENT surgery were the main confounding factors. At study onset they almost cause a defined separation of both treatment groups. As a result estimated treatment differences vary substantially depending on the chosen statistical model. CONCLUSIONS: When comparing complementary and conventional treatments, non-randomised clinical trials may be misleading. Results may be strongly biased even when advanced statistical methods are used. Trials of complex statistical designs are needed to give valid results.

Acute Disease↗

PubMed1998

Physical fitness influences water turnover and body water changes during trekking.

PURPOSE: This study was performed to assess water turnover and changes of body water during a trekking tour at moderate altitude. METHODS: Fifteen healthy normally trained adults participated in a 7-d backpack trek tour in the Swiss Alps (total walking distance: 120.5 km; cumulated altitude difference: 6990 m (uphill) and 7550 m downhill; lowest point: 1285 m; highest point: 3317 m). Total body water and water turnover were measured using deuterium dilution and elimination (oral load of 0.33 g 99.8% D2O per kg body weight, overnight equilibration period, pre- and postdose saliva samples immediately before and after sleep, analysis of D2O concentrations in saliva using Fourier-transform infrared spectroscopy, CV < 1%). Physical training state was assessed after the tour using the lactate-exercise intensity relationship obtained by performing 50-W increments every 3 min on a cycle ergometer. RESULTS: Body water decreased from the evening of day 0 to the evening of day 4 (from 45.3 +/- 7.3 L to 43.4 +/- 7.6 L, P < 0.05), and did not significantly decrease (43.5 +/- 7.9 L) until the evening of day 5 (maximum of trekking exercise intensity). Mean daily water turnover was 5.7 +/- 1.8 L x d(-1) corresponding to 78.7 +/- 17.5 mL x kg(-1) x d(-1). Body water changes and water turnover were significantly related to the exercise intensity obtained at the lactate threshold as well as at the level of 4 mM lactate. CONCLUSIONS: This correlation may be in part explained by differing glycogen content of muscle tissue.

Adult↗

PubMed1997

[Homeopathic treatment of adenoid vegetations. Results of a prospective, randomized double-blind study].

In a monocenter prospective randomized double-blind clinical trial the efficacy of homeopathic treatment was investigated on children with adenoid vegetations justifying an operation. Patients were treated with either homeopathic remedies such as Nux vomica D200, Okoubaka D3, Tuberculinum D200, Barium jodatum D4 and Barium jodatum D6 or with placebo. The duration of the study for each patient was 3 months. Examination of the ears using a microscope, rhinoscopy, stomatoscopy and pharyngoscopy, as well as tympanometry and audiometry were performed after 4, 8 and 12 weeks. Out of a total of 97 children studied between the ages of 4 to 10 years 82 could be analyzed. At the end of the study no operation was required in 70.7% of the placebo-treated children and in 78.1% of the children treated with homeopathic preparations. These results show no statistical significance.

Adenoids↗

PubMed1997

Evaluation of myelination and myelination disorders with turbo inversion recovery magnetic resonance imaging.

The aim of our work was to determine the efficacy of turbo inversion recovery spin echo (TIRSE) pulse sequences in differentiating patients with normal and abnormal myelination. Twenty neurological normal children (aged 5 months to 12 years) as well as 65 children presenting clinically with neurologic developmental deficits (aged 2 months to 10 years) were examined using TIRSE, T1-weighted SE, and T2-weighted turbo SE pulse sequences. Contrast-to-noise-ratio (CNR) between myelinated white and gray matter was compared for the different pulse sequences. In addition, two readers analyzed all images qualitatively by consensus. The CNR values were significantly higher on TIRSE images as compared with conventional images (p < 0. 05). Forty-two neurologically abnormal patients displayed a normal myelination on all sequences, whereas 23 showed an abnormal myelination. The TIRSE sequence provided a sensitive and specific depiction of an abnormal myelination in all of these patients. The TIRSE sequence provided additional information to conventional pulse sequences in determining myelination disorders in children, especially in children older than 2 years.

Adolescent↗

PubMed1997

The homoeopathic treatment of otitis media in children--comparisons with conventional therapy.

In a prospective observational study carried out by 1 homoeopathic and 4 conventional ENT practitioners, the 2 methods of treating acute pediatric otitis media were compared. Group A received treatment with homoeopathic single remedies (Aconitum napellus, Apis mellifica, Belladonna, Capsicum, Chamomilla, Kalium bichromicum, Lachesis, Lycopodium, Mercurius solubilis, Okoubaka, Pulsatilla, Silicea), whereas group B received nasal drops, antibiotics, secretolytics and/or antipyretics. The main outcome measures were duration of pain, duration of fever, and the number of recurrences after 1 year, whereby alpha < 0.05 was taken as significance level. The secondary measures were improvement after 3 hours, results of audiometry and tympanometry, and necessity for additional therapy. These parameters were only considered descriptively. The study involved 103 children in group A and 28 children in group B, aged between 6 months and 11 years in both groups. For duration of pain, the median was 2 days in group A and 3 days in group B. For duration of therapy, the median was 4 days in group A and 10 days in group B: this is due to the fact that antibiotics are usually administered over a period of 8-10 days, whereas homoeopathics can be discontinued at an earlier stage once healing has started. Of the children treated, 70.7% were free of recurrence within a year in group A and 29.3% were found to have a maximum of 3 recurrences. In group B, 56.5% were free of recurrence, and 43.5% had a maximum of 6 recurrences. Out of the 103 children in group A, 5 subsequently received antibiotics, though homoeopathic treatment was carried through to the healing stage in the remaining 98. No permanent sequels were observed in either group.

Anti-Bacterial Agents↗

PubMed1996

Water turnover and body composition during long-term exposure to high altitude (4,900-7,600 m).

Thirteen healthy subjects (11 men and 2 women; 30.2 +/- 5.4 yr; 73.5 +/- 10.3 kg; 178.9 +/- 10.4 cm; body mass index, 22.9 +/- 1.6 kg/m2) participated at the 62-day expedition to the Broad Peak (8,047 m), Pakistan. Weight, body water, and water turnover (deuterium dilution and elimination) were measured eight times to assess long-term changes. Body weight fell during the ascent to the base camp [from 73.2 +/- 9.8 (baseline) to 71.7 +/- 9.7 kg; P < 0.05] and decreased until the end of the base camp stay (66.7 +/- 7.2 kg; P < 0.0001). Body compartments changed at different rates. Total body water decreased during the ascent (from 43.1 +/- 7.3 to 41.0 +/- 7.7 liters; P < 0.05) and remained unchanged until the base camp was reached (41.2 +/- 6.9 liters; P < 0.01) but decreased further during the base camp stay (40.6 +/- 5.2 liters). Water content of the body (total body water-to-body weight ratio) fell during the ascent (from 58.6 +/- 3.4 to 55.8 +/- 4.4%; P < 0.01), approached the baseline value during the base camp (57.4 +/- 4.0 and 58.3 +/- 5.1%), and increased again until the end of the base camp (60.6 +/- 3.4 and 60.9 +/- 4.3%). The compartment of the solids increased during the ascent (from 30.2 +/- 3.4 to 32.2 +/- 4.9 kg; P < 0.01) and approached the baseline value on arrival at the base camp (30.5 +/- 4.7 kg). Until the end of the base camp, the compartment of the solids fell (26.9 +/- 2.6 and 26.1 +/- 4.0 kg), indicating that weight loss was due to a loss of body solids, presumably mostly fat mass. Water turnover during the pretest period (sea level) was 45 +/- 7 ml.kg-1.day-1; it increased during the ascent (56 +/- 11 and 60 +/- 10 ml.kg-1.day-1) but remained constant during the base camp stay (63 +/- 12, 58 +/- 9, and 56 +/- 10 ml.kg-1.day-1). It increased during the ascent to Broad Peak (73 +/- 20 ml.kg-1.day-1; P < 0.05) and even more during the descent to civilization (83 +/- 17 ml.kg-1.day-1; P < 0.05).

Adult↗

PubMed1996

[Acute otitis media in children. Comparison between conventional and homeopathic therapy].

Within a prospective group study of five practicing otorhinolaryngologists, conventional therapy of acute otitis media in children was compared with homeopathic treatments. Group A (103 children) was primarily treated with homeopathic single remedies (Aconitum napellus, Apis mellifica, Belladonna, Capsicum, Chamomilla, Kalium bichromicum, Lachesis, Lycopodium, Mercurius solubilis, Okoubaka, Pulsatilla, Silicea). Group B (28 children) was treated by decongestant nose-drops, antibiotics, secretolytics and/or antipyretics. Comparisons were done by symptoms, physical findings, duration of therapy and number of relapses. The children of the study were between 1 and 11 years of age. The difference in numbers was explained by the children with otitis media being primarily treated by pediatricians using conventional methods. The median duration of pain in group A was 2 days and in group B 3 days. Median therapy in group A lasted 4 days and in group B 10 days. Antibiotics were given over a period of 8-10 days, while homeopathic treatments were stopped after healing. In group A 70.7% of the patients were free of relapses within 1 years and 29.3% had a maximum of three relapses. Group B had 56.5% without relapses and 43.5% a maximum of six relapses. Five children in group A were given antibiotics and 98 responded solely to homeopathic treatments. No side effects of treatment were found in either group.

Acute Disease↗

PubMed1993

Water turnover of healthy children measured by deuterated water elimination.

For healthy children up to 15 years of age, no data exist regarding water turnover as directly measured using stable isotope techniques. Water turnover was measured in 171 healthy children (88 girls, 83 boys, age: 6 weeks-15 years) whilst living in their normal environment. Water turnover was calculated from the equilibrium of 2H2O concentration reached in the urine 2-3 h after an oral test load of 2 ml 2H2O/kg and the subsequent elimination rate of 2H2O. Daily water turnover decreased from 160 ml/kg (3 months), 100 ml/kg (12 months), 65 ml/kg (3 years) to 40 ml/kg at 15 years of age. Fluid intake was then calculated by subtracting the estimated metabolic water production from water turnover and this data was compared with recommended values. Our calculation of spontaneous daily fluid intake for these healthy children is within the recommended range during the 1st year of life, whereas for older children the recommendations exceed the spontaneous intake by a factor of 1.2-2.

Adolescent↗

PubMed1993

Fourier transform infrared spectroscopy measures 1H/2H ratios of native water with a precision comparable to that of isotope ratio mass spectrometry.

A fast and easy method is described which uses Fourier transform infrared spectroscopy (FT-IR) to measure the 1H/2H ratio of aqueous samples of less than 100 microliters with high precision (+/- 0.2-0.5% in the range of 89 to 2680 microliters/l). Using a thermostat-controlled CaF2 cell, low resolution absorption specta (8 cm-1) are measured. The integral of absorption in the range of 2600 and 2460 cm-1 (O2H vibration) is used to analyse the 2H content of the sample. For measurements at low enrichment five standards are used (SLAP: 89.00 microliters/l, GISP: 126.3 microliters/l, V-SMOW: 156.0 microliters/l, all from the International Atomic Energy Agency, Vienna, Austria, standard 1: 183.3 microliters/l, standard 2: 222.5 microliters/l, both prepared by weighing and controlled by isotope ratio mass spectrometry (IR-MS)). For measurements at high enrichment three standards are used (standard 2: 222.5 microliters/l, standard 3: 1323 microliters/l, standard 4: 2680 microliters/l, all prepared by weighing and controlled by IR-MS). Measured and reported 2H concentrations coincide very well, two samples for quality control (145 and 1612 microliters/l) were measured with a precision of 0.3 and 0.4% corresponding to +/- 0.5 and 5.9 microliters/l.

Deuterium↗

PubMed1993

Measurement of water turnover using a stable isotope technique: calculation of error propagation.

Water turnover may be determined with stable isotope techniques from the product of tracer dilution space and tracer elimination rate. Tracer concentrations must be measured in two body fluid samples which are separated by a sampling interval. The tracer concentration of the first sample may be charged with an error which may be due to analytical errors, incomplete tracer dilution or because the necessary steady-state assumption (water influx equals water efflux) is violated at the moment of tracer loading. Error propagation shows that the influence of this error on the estimation of water turnover is partially compensated for. The goodness of compensation depends on the sampling interval and on the magnitude of the error of the first sample. The error is best compensated using sampling intervals of 1.5 tracer half life.

Body Water↗

PubMed1992

Androgen receptors in prostatic tissue: evaluation of systematic errors and comparison of three procedures to correct for nonspecific binding sites in the binding assays.

In androgen receptor analysis, nonspecific binding can distort the measurement of the binding constants of the receptor ligand complex. We evaluate this influence with a one-ligand two-binding sites model. The binding constants correspond to those of androgen receptors in prostatic tissue. Three procedures which correct for the influence of nonspecific binding sites are compared: difference of bound radioligands measured in both assays (assay 1: only radioligand, assay 2: additional unlabelled ligand in excess), nonlinear regression, and difference of bound radioligands corrected by the ratio of the free radioligands. The subtraction of bound radioligands causes considerable errors in the estimation of the total concentration of receptor binding sites. Nonlinear regression yields the correct result when the influence of nonspecific binding is moderate. The corrected difference of bound ligand gives the correct results even in the range where nonlinear regression fails. We conclude that the latter method corrects for the influence of nonspecific binding as effectively as nonlinear regression and suggest that the free fraction of radioligand should be measured and not discarded, as it is common in the clinical practice.

Binding Sites↗

PubMed1991

[Short-term infusion therapy in childhood. A comparison of individually mixed with commercial infusion solutions].

Data of parenteral sodium dosage in healthy children recommended by several textbooks vary by the factor 4. Therefore, we studied the effect of low and high i.v. dosage administered in 5-5.5% glucose for 12 hrs to probands without renal disease. Group 1: n = 13; Na 2.2 +/- 0.4, K 1.7 +/- 0.2, Cl 4.2 +/- 0.6 mmol/kg/d, individually composed solutions. Group 2: n = 17; Na 5.1 +/- 1.3, K 1.6 +/- 0.5, Cl 5.8 +/- 1.5, acetate 2.4 +/- 0.6 mmol/kg/d; Ca, Mg, malate, glycerol phosphate below 0.3 mmol/kg/d; commercial ready-for-use mixtures. Compared to the control period, the excretion of Na into the urine was unchanged in group 1 during the infusion but significantly lowered in group 2. Regression analysis reveals that infusion of 2.7 mmol Na/kg/d would have given a balanced sodium balance. The real parenteral requirement, however, may be below this value, as the excretion of Na during the control period indicates that the probands in both groups were overloaded with Na before the beginning of the study. During infusion, the renal clearance of creatinine was unchanged in group 1 but significantly lowered in group 2 (131 +/- 58 vs. 94 +/- 38 ml/min/1.73 m2; p less than 0.01). We would like to recommend to elucidate the mechanism and the clinical significance of this effect before using the commercial solution in clinical routine.

Adolescent↗

PubMed1988

[Pentoxyverine poisoning via maternal milk in a fully breast-fed newborn infant].

A four-week-old male infant who had been exclusively breast-fed by his mother developed acute respiratory failure with intermittent arrest of breathing for up to 15 sec, in between sighing breaths and normal ones. For two weeks his mother had been taking pentoxyverine-containing cough drops for an upper respiratory tract infection. Pentoxyverine was demonstrated in maternal serum and breast milk, as well as the child's serum and urine, in some in very high concentrations. The course of the illness and comparison with reported instances of pentoxyverine poisoning in infants makes it likely that this, too, was such a case.

Adult↗

PubMed1988

Receptor analysis: an arithmetic correction improves precision and accuracy.

Data of receptor analysis by ligand binding experiments should be processed using the formula DCORR = (B1 - B2.F1/F2)/VS.DCORR is an estimate of the concentration of receptor-bound radioligand; B1 and F1 are estimates of bound and free radioligand in assay 1; B2 and F2 are the corresponding values obtained from the parallel assay 2, which contains an additional excess of nonlabeled ligand; VS is the volume of assays 1 and 2 that was submitted to separation. DCORR will be superior to the conventional formula, D = (B1 - B2)/VS, if the radiolabeled receptor-ligand complexes are incompletely separated from nonspecifically bound and free radioligands. DCORR corrects for the systematic underestimation of the specifically bound radioligand implicated in D as well as for random errors due to imprecise pipetting during preparation of the parallel assays. The superiority of DCORR over D is verified by processing the data of androgen receptor analyses using agar gel electrophoresis for separation of bound and free radioligand.

Animals↗

PubMed1988

Seasonal and diurnal changes of prostatic androgen receptor and circulating testosterone in young mature rats.

Low- and high-salt (600 mM KCl) extractable androgen receptors were measured in the ventral prostate lobes of 70-day-old rats which were housed in constant environmental conditions (22 +/- 2 degrees C, 65 +/- 5% air humidity, light 6.00h-18.00h). Seasonal variations were observed during 2 years, exhibiting elevations in late summer and autumn and depressions in late winter and spring time. These fluctuations were superposed by steep changes from month to month. The maximum and minimum values of the low- and high-salt extractable receptors differed within 1 year by a factor 8.5 and 2.4, respectively. Both receptor fractions showed a diurnal rhythm as measured during 1 day in January with maximal concentrations at 9.00 h (low-salt: median = 1308 fmol/mg DNA) and minimal values at 18.00 (424) and 24.00 (230). The electrophoretic mobility in agar gel of pH 8.2 also showed a diurnal variation with maximal values at 18.00 h in either receptor fraction. Neither the seasonal nor the diurnal variations were correlated to the corresponding rhythms of serum testosterone concentrations. As steroid receptors may be regulated by neural transmission, in a final experiment the parasympathic innervation of the prostate was blocked by infiltrating the plexus pelvicus with a local anesthetic drug. One hour later, the total receptor concentration was not changed, while the ratio of low- to high-salt extractable receptors and the electrophoretic mobility of both fractions were elevated as compared to the control animals. This finding indicates that peripheral neural transmission rather than circulating testosterone may be involved in the regulation of androgen receptors in rat ventral prostate.

Animals↗

PubMed1988

Measurement of D2O concentrations at tracer levels in small samples obtained from paediatric patients.

A micro-method is described for the determination of trace amounts of D2O in serum, saliva and urine, requiring 100 microliters of sample. H2O/D2O are rapidly isolated from serum, saliva or urine by vacuum distillation. D2O concentrations in H2O are detected by infrared spectroscopy utilizing the integrated absorption of the OD-bond at 2510 cm-1 in the range of 2675 to 2460 cm-1. Calibration is done using standard solutions of H2O/D2O. The separation of D2O/H2O is necessary because of the varying background absorption of the sample. The recovery of D2O after distillation is 100%. The absolute error is 25 mg/kg (+/- 2 s) of D2O leading to a precision of 17.5% at 150, 2.8% at 1000, 1.3% at 2000, 0.9% at 3000, 0.7% at 4000 and 0.5% at 5000 mg/kg of D2O. The usefulness of the method is evaluated by 9 determinations of total body water and water turnover in 7 healthy subjects drinking a mixture of H2O/D2O. Total body water related to body surface is 23.3 +/- 0.9 l/m2 in males and 20.5 +/- 1.5 l/m2 in females. Water turnover is determined by analysing the decrease of D2O concentrations in blood between 6 and 31 days. A mean of 1.53 +/- 0.13 l/m2.d in males in 1.48 +/- 0.17 l/m2.d in females was found.

Adult↗