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Biomedical subjects

R Noack

Publications and source records attributed to R Noack.

At least 19 recordsLinked to original sources
PubMed2001

Estimation of available energy of dietary fibres by indirect calorimetry in rats.

BACKGROUND: Knowledge of energetic availability of dietary fibres is important for human nutrition. But up to now results are often different and depend on the methods used. Estimation of metabolisable energy of dietary fibres (mainly by balance technique) is a time-consuming procedure and needs special technical effort. AIM OF THE STUDY: Validation of the experimental design for short-term studies by using indirect calorimetry with feeding below maintenance requirement to evaluate the energetic availability of dietary fibres and their influence on absorption velocity of carbohydrates (CHO). METHODS: Energy expenditure and CHO oxidation (including short-chain fatty acids as fermentation products) were estimated in Wistar rats over 23 h after being fed a basal diet for the first day (300 KJ/kg0.75, 20% protein, 3% fat, 77% CHO) followed by supplementation with either microcrystalline cellulose, the soluble rye fibre arabinoxylan, apple pectin, amylomaize starch (with 48% of resistant starch) or gelatinised wheat starch (200 KJ/kg0.75 each) as control for the following days. Energetic availability was determined by comparing the increase of CHO oxidation after addition of gelatinised wheat starch with that of the dietary fibres tested. RESULTS: In comparison to wheat starch (100%), the following energetic availability of the dietary fibres was found: microcrystalline cellulose 14%, arabinoxylan 33%, pectin 39%, amylomaize starch 62%. The time-course of CHO oxidation indicated that microcrystalline cellulose enhances, whereas the soluble rye fibre slows down the velocity of CHO absorption due to the different consistency of the intestinal contents modified by the kind and properties of the used dietary fibres. After intake of arabinoxylan or pectin, CHO oxidation remained at a higher level during the experimental period elucidating an increased activity of fermentation to short-chain fatty acids. CONCLUSIONS: Short-term experiments in rats using indirect calorimetry are a suitable method for comparative estimation of the energetic availability of dietary fibres. Results are partly in agreement with values estimated by long-term in vivo methods.

Animals↗
PubMed2001

Modification of oral mucositis by keratinocyte growth factor: single radiation exposure.

PURPOSE: The aim was to quantify the effect of recombinant human keratinocyte growth factor (rhKGF) on acute oral mucositis induced by a single radiation dose, simulating accidental radiation exposure. MATERIAL AND METHODS: Tongue epithelium of the C3H/Neu mouse was irradiated with graded single doses of 25 kV X-rays to a 3 x 3 mm2 area in the centre of the lower tongue surface. Acute mucosal ulceration, as a clinically relevant reaction, was used as the quantal endpoint for dose response analyses by probit analysis. As a secondary endpoint the time-course, i.e. time to first diagnosis of ulcer (latent time) and individual ulcer duration, was analysed. KGF was applied before, after or in combination before and after radiation exposure. RESULTS: Administration of KGF in all protocols resulted in a significant reduction of the incidence of oral mucosal ulceration, as illustrated by an increase in iso-effective dose from 10.9 to 24.9 Gy; the corresponding dose-modification factors ranged between 1.7 and 2.3. The effect was most pronounced when KGF was applied after irradiation. In all protocols where KGF was given after irradiation, a significant shortening of the latent time to ulceration from 11 to 6-8 days was observed. CONCLUSIONS: The mechanisms underlying the amelioration of the oral mucosal response to single-dose irradiation remain unclear. However, KGF represents a promising approach for the effective management of acute radiation reactions in oral, gastrointestinal and cutaneous epithelia after radiation exposure.

Animals↗
PubMed2000

Weight loss, weight maintenance, and improved cardiovascular risk factors after 2 years treatment with orlistat for obesity. European Orlistat Obesity Study Group.

OBJECTIVE: To determine the effect of orlistat, a new lipase inhibitor, on long-term weight loss, to determine the extent to which orlistat treatment minimizes weight regain in a second year of treatment, and to assess the effects of orlistat on obesity-related risk factors. RESEARCH METHODS AND PROCEDURES: This was a 2-year, multicenter, randomized, double-blind, placebo-controlled study. Obese patients (body mass index 28 to 43 kg/m2) were randomized to placebo or orlistat (60 or 120 mg) three times a day, combined with a hypocaloric diet during the first year and a weight maintenance diet in the second year of treatment to prevent weight regain. Changes in body weight, lipid profile, glycemic control, blood pressure, quality of life, safety, and tolerability were measured. RESULTS: Orlistat-treated patients lost significantly more weight (p<0.001) than placebo-treated patients after Year 1 (6.6%, 8.6%, and 9.7% for the placebo, and orlistat 60 mg and 120 mg groups, respectively). During the second year, orlistat therapy produced less weight regain than placebo (p = 0.005 for orlistat 60 mg; p<0.001 for orlistat 120 mg). Several obesity-related risk factors improved significantly more with orlistat treatment than with placebo. Orlistat was generally well tolerated and only 6% of orlistat-treated patients withdrew because of adverse events. Orlistat leads to predictable gastrointestinal effects related to its mode of action, which were generally mild, transient, and self-limiting and usually occurred early during treatment. DISCUSSION: Orlistat administered for 2 years promotes weight loss and minimizes weight regain. Additionally, orlistat therapy improves lipid profile, blood pressure, and quality of life.

Adult↗
PubMed1999

Validation of a self-administered food-frequency questionnaire administered in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study: comparison of energy, protein, and macronutrient intakes estimated with the doubly labeled water, urinary nitrogen, and repeated 24-h dietary recall methods.

BACKGROUND: The validation of dietary assessment instruments is critical in the evaluation of diet as a chronic disease risk factor. OBJECTIVE: The objective was to assess the validity of a self-administered food-frequency questionnaire by comparison with dietary recall, urinary nitrogen excretion, and total energy expenditure data. DESIGN: Over a 1-y period, data from twelve 24-h dietary recalls, a food-frequency questionnaire, and four 24-h urine samples were obtained from 134 study participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study in Potsdam, Germany. In a substudy of 28 participants, total energy expenditure from doubly labeled water measurements was assessed. RESULTS: Energy-adjusted, deattenuated correlation coefficients between the questionnaire and the recalls ranged from 0.54 for dietary fiber to 0.86 for alcohol. Cross-classification of quintiles of nutrient intakes from the questionnaire and recalls indicated severe misclassification to be <4%. Reported protein intake correlated with estimated protein excretion (r = 0.46). Energy intake and total energy expenditure were also significantly correlated (r = 0.48); however, all but one subject underreported their energy intake. The magnitude of underreporting varied considerably, by 22% on average, and increased slightly with increasing energy intake. A similar pattern of underreporting was observed when energy intakes from the 24-h dietary recalls were compared with total energy expenditure. CONCLUSIONS: These data indicate an acceptable relative validity of the food-frequency questionnaire in this study population. Compared with measurements of total energy expenditure and protein excretion, however, only moderate agreement with both the food-frequency questionnaire and the 24-h dietary recalls was observed.

Adult↗
PubMed1998

Multicenter, randomized, double-blind comparison of erythromycin estolate versus amoxicillin for the treatment of acute otitis media in children. AOM Study Group.

Erythromycin is frequently prescribed in Germany for acute otitis media, but well-designed clinical trials under present epidemiological conditions are lacking. Therefore, a double-blind, randomized, multicenter trial was performed to compare the clinical efficacy and safety of erythromycin estolate versus amoxicillin in children with acute otitis media and to identify the risk factors associated with clinical failure. Investigators from 19 centers throughout Germany recruited 302 children with clinical, otoscopic, and tympanometric evidence of acute otitis media. In a double-blind fashion, patients were allocated randomly to a 10-day course of erythromycin estolate at 40 mg/kg/day in two divided doses or amoxicillin at 50 mg/kg/day in two divided doses. Clinical examinations, otoscopy, and tympanometry were performed at baseline, day 3-5, day 9-11, and at 5 weeks. Clinical outcome was assessed on day 9-11. Two-hundred eighty children were evaluable for efficacy (erythromycin group, 141; amoxicillin group, 139). Both groups were comparable with respect to demographic data and severity of disease at entry. Treatment was successful in 94% of the erythromycin-treated patients and in 96% of the amoxicillin-treated patients. Clinical outcome was statistically equivalent between groups within a range of 7 percentage points. Clinical recurrence was seen in eight erythromycin-treated children (5.7%) and in seven amoxicillin-treated children (5.0%) (P=0.81). Patients with bilateral disease at entry were at higher risk of unfavourable outcome, whereas age and presence/absence of otorrhea at entry were not associated with outcome. Treatment-related adverse events were recorded in eight (5.3%) of 151 erythromycin-treated patients and in 11 (7.3%) of 151 amoxicillin-treated patients. In this study in an outpatient setting in Germany, erythromycin estolate was as safe and effective as amoxicillin in the treatment of acute otitis media. Both drugs can be administered in a convenient twice-daily dosage schedule.

Acute Disease↗
PubMed1997

Determination of total energy expenditure, resting metabolic rate and physical activity in lean and overweight people.

A new 2H/1H and 18O/16O equilibration device was tested, standardized and employed for the determination of total energy expenditure. It was shown that overweight men and women have increased resting metabolic rate as well as increased total energy expenditure when compared to their lean counterparts. The physical activity level (PAL)index was slightly decreased which possibly suggests a decreased physical activity in obese people.

Adult↗
PubMed1996

Changes in energy metabolism and metabolite patterns of obese rats after application of dexfenfluramine.

Serotonergic neuronal networks are important for food intake and body weight regulation. Dexfenfluramine (dF), a serotonin releaser and reuptake inhibitor, was used to investigate changes in food intake, body weight development, energy expenditure, respiratory quotient, and substrate oxidation rates for 12 days. Rats, which had been made obese by early postnatal overfeeding, received an energy-controlled mash diet and water ad lib and were intraperitoneally injected daily with either saline, 5 or 10 mg dF/kg. Compared to controls, food intake, body weight development, and energy expenditure were decreased in a dose-dependent manner, especially during the first 6 days. Lipid oxidation was increased while oxidation of carbohydrates was decreased. Pair-feeding experiments over 2 days revealed that this was not solely a result of diminished food intake but also an additional metabolic effect of dF, different from its anorectic effect. At the end of these experiments, plasma glucose and liver glycogen were unchanged after dF, but plasma free fatty acids were significantly decreased. Insulin-sensitivity was probably improved, indicated by decreased insulin levels and increases in muscle glycogen contents and activities of muscle pyruvate kinase. Liver-glutamine and contents of valine, leucine, and isoleucine in the muscle were significantly decreased after dF-treatment, the latter indicating a diminished proteolysis. The plasma tryptophan/large neutral amino acids ratio of the dF-rats was unchanged but that of the paired-fed rats was changed, despite similar changes in food intake. It is concluded that both increased oxidation of endogenous fat and reduced food intake could mediate the body weight reducing effect of dF.

Animals↗
PubMed1996

Energy expenditure and substrate oxidation rates of obese rats during a 12-day treatment with dexfenfluramine.

Serotoninergic neuronal networks are included in regulation and modification of eating behavior and energy metabolism. Dexfenfluramine (dF), a serotonin releaser and reuptake inhibitor, was used to investigate changes in food intake, body weight development, energy expenditure, respiratory quotient, and substrate oxidation rates for 12 days. Rats which had been made obese by postnatal overfeeding received an energy-controlled mash diet and water ad libitum and were intraperitoneally injected with either saline or 5 or 10 mg dF/kg. As compared with controls, food intake and energy expenditure were significantly decreased in a dose-dependent manner, especially during the first 6 days. Lipid oxidation was increased, while the oxidation of carbohydrates was decreased. The body weight was only slightly reduced after 2 days of dF treatment. After 4 days, dF-treated rats resumed body weight, but as compared with controls both dF groups exhibited lower body weights at the end of the experiment. After 12 days the plasma glucose concentration was unchanged, whereas plasma free fatty acids were significantly decreased. Plasma insulin levels were unchanged after dF, but 10 mg dF/kg led to increased muscle and, especially liver glycogen contents, indicating an improved nonoxidative glucose disposal. Muscle pyruvate kinase was slightly but not significantly increased after dF treatment but that of the liver was significantly decreased, indicating a reduced glycolytic activity of the liver. Whereas the renal N excretion was rather decreased, the plasma concentrations of urea, citrulline, arginine, and ornithine were increased, and the liver contents of glutamine and arginine were decreased. Possibly, there is a shift of ammonia removal from glutamine synthesis to production of urea. The sum of all large neutral amino acids in muscle was significantly decreased after dF treatment, indicating a diminished proteolysis. Pair-feeding experiments over 2 days revealed that this was not solely a result of diminished food intake, but also an additional metabolic effect of dF, different from its anorectic effect. It is concluded that both increased oxidation of endogenous fat and reduced food intake could mediate the body weight reducing effect of dF.

Amino Acids↗
PubMed1994

Energy metabolism and metabolite patterns of rats after application of dexfenfluramine.

Serotoninergic neuronal networks are important for food intake and body weight regulation. However, the mechanisms by which some metabolic pathways are influenced are rather unclear. Dexfenfluramine (DF), a serotonin releaser and re-uptake inhibitor, was used to investigate changes in food intake, body weight development, energy expenditure, respiratory quotient and substrate oxidation rates for 12 days. Normal rats, receiving an energy-controlled mash diet and water ad libitum were intraperitoneally injected daily with either saline, 1, 2.5, 5 or 10 mg DF/kg. Compared to controls, food intake, body weight development and energy expenditure were decreased in a dose-dependent manner, especially during the first six days. Lipid oxidation was increased while oxidation of carbohydrates was decreased. Pair-feeding experiments over three days revealed that this was a clear pharmacological effect and not simply a result of diminished food intake. At the end of these experiments, plasma glucose and liver and muscle glycogen were unchanged after DF, but isoleucine, leucine and lysine were significantly decreased in plasma and liver. Therefore, the plasma tryptophan/large neutral amino acids ratio was slightly increased. Protein oxidation was unchanged after DF. It is concluded that a prompt decline in energy expenditure with increased fat oxidation rates could mediate the body weight reducing effect of DF.

Amino Acids↗
PubMed1993

Postprandial thermogenesis of rats with glutamate induced obesity in relation to energy intake.

Postprandial thermogenesis was estimated in 4-month-old male rats with glutamate induced obesity after being fed with 300, 450 and 600 kJ/kg0.75 of a pellet diet, respectively by indirect calorimetry in computer-controlled open circuit metabolic cages over 8 h. After an intake of 600 kJ/kg0.75 (above the maintenance energy requirement) postprandial thermogenesis was significantly reduced in the obese animals to about 40% of control rats (12.0 versus 31.5 kJ/kg0.75 x 8h). It is concluded that the glutamate obese rat can be accepted as an animal model with impaired facultative thermogenesis, mainly caused by a reduction of sympathetic adrenergic activity.

Animals↗
PubMed1993

Intra- and inter-individual variations in energy expenditure of 14-15-year-old schoolgirls as determined by indirect calorimetry.

Eleven 14-15-year-old schoolgirls were investigated four times within 1 year to determine variations in energy expenditure between individuals (inter-individual variability) and within subjects (intra-individual variability). Indirect calorimetry was used to determine metabolic rates in the fasting and resting state (RMR), and during physical activities which were grouped into standardized and non-standardized activities. Analyses of variance supplied information about intra- and inter-individual variabilities of rates of energy expenditure. The mean resting metabolic rate in adolescent girls was 4.41 (SD 0.40) kJ/min. The overall coefficient of variation (9.1%) was approximately twice as high as the mean coefficient within subjects (4.3%). The reproducibility of the RMR of the girls was high (significant F value of variance analysis), even over a prolonged investigation of 1 year. This seemed to depend primarily on the constant body weight during the period of investigation. A workload of 30 W on a bicycle ergometer and walking at an individually chosen speed did not reveal significant differences between inter- and intra-individual variabilities of energy metabolic rates. However, in most non-standardized activities, e.g. relaxation at home, washing dishes and vacuum cleaning, inter-individual variability was significantly higher than intra-individual variability. There are true differences in energy expenditure rates between subjects which may be demonstrated by duplicated measurements. Conclusions on future experimental design were drawn, where differences between groups rather than between individuals are to be studied.

Adolescent↗
PubMed1993

[Hemophilus influenzae infection and their prevention by vaccination].

Encapsulated and non-encapsulated strains of haemophilus influenzae are known to exist. The encapsulated ones, especially those of type B (HiB), are highly invasive. Hib may cause, among other diseases, purulent meningitis, epiglottitis, septic arthritis/osteomyelitis and pneumonia. These diseases can be prevented by timely vaccination. The non-encapsulated haemophilus ionfluenzae strains often produce colonisation of the nasopharyngeal space and inflammation of the mucosa of the airways. They are often pathogens of otitis media, sinusitis, bronchitis and pneumonia. These diseases cannot be prevented by HiB vaccination.

Antibodies, Bacterial↗
PubMed1992

[A new vaccination schedule].

In July 1991 a new vaccination strategy has been recommended. Two alterations are involved; the general recommendation of the pertussis immunization and a second MMR vaccination. Comments are given on BCG-, pertussis-, MMR- and HIB-vaccinations. The continued existence or the new foundation respectively of medical advisory boards on immunization problems in all states of the Federal Republic of Germany are strongly recommended.

Child↗
PubMed1991

Prediction of total body lipid from total body water in rats. Part 2. In vivo estimation of total body lipid by tritium water dilution.

Body composition data estimated for normal young, normal adult, and adult obese Wistar rats by a tritiated water (THO) dilution procedure (b. wt. range 119-237 g, n = 31; 305-597 g, n = 43; 274-381 g, n = 6) were compared with the results of whole body analysis. As for the predicted total body lipid (TBL), the content was calculated from the virtual THO-dilution space estimated by a simple micro-method and a regression equation between TBL [%] and DM [%] (dry matter) content (Part 1. Relations between directly measured major body components. Nahrung 35 (1991) 581. Due to different degrees of overestimations in the animal groups examined, the THO-space can be corrected via subtraction of 3.8%, 2.2% and 1.1% in the sequence young, obese, and adult groups. The derived TBL [%] data show a non-significant deviation of less than 1 g/100 g b. wt. in comparison to the three group means after direct lipid determinations. In the best case, i. e. after the additional elimination of extremely overestimated values for total body water (outliers) the combined tritium-derived lipid values (y) are correlated with the lipid data obtained analytically (x), both as proportion of the body weight, by the regression equation y = 0.848 + 0.963 x, r = 0.985, Sy.x = 1.77, n = 58. For a group of young rats (n = 14) after a pre-experimental supplementation with a sucrose solution, TBL values, not significantly different from analytically determined ones, could be calculated without any corrections.

Animals↗
PubMed1991

[Type B Haemophilus influenzae infections: epidemiology, vaccination, chemoprophylaxis].

In the new countries of the Federal Republic Germany the incidence of systemic Hib-infections is lower than in the old FRG. In children under the age of 5 years the incidence of Hib-meningitis is 8/100,000 and of all systemic Hib-diseases about 17/100,000. By Hib-vaccination (PRP-D) severe diseases can be prevented. The recommended chemoprophylaxis with Rifampicin is important in this connection, too.

Bacterial Vaccines↗
PubMed1990

[Recommendations for the diagnosis and therapy of meningitis, Waterhouse-Friderichsen syndrome and encephalitis in childhood].

Representatives of the working group of "Neuropaediatrics" and "Infectology" like to present recommendations on diagnostics and treatment of infectious diseases on the CNS. Individual opinions can not be considered in recommendations always. Therefore we have to understand these recommendations in this way that individual decisions will not be restricted in special situations.

Child↗