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Biomedical subjects

F Rauch

Publications and source records attributed to F Rauch.

68 records · Page 4Linked to original sources
PubMed1996

Free deoxypyridinoline in urine and serum--results in children and adolescents.

The urinary excretion of the collagen crosslinking compound dexoypyridinoline (DPD) is considered a specific index of bone resorption. Here we report on the levels of free (i.e., non peptide-bound) DPD in the urine and serum of subjects from 5 to 19 years of age, as determined by a new radioimmunoassay. Reference values for free DPD were established using 24-h urine collections from 118 healthy children and serum samples from 133 children with acute febrile illnesses. Serum and urine levels of free DPD were compared in samples from 23 short, normal children. Additionally, total (the sum of peptide-bound and free) DPD was measured by high-performance liquid chromatography in the 24-h urine collections. Urinary-free DPD was significantly correlated with total DPD (r = 0.90; P < 0.001) and declined steadily with age. Serum levels of free DPD ranged from 0.9 to 5.7 nmol/l and varied with age in boys only. No significant association was found between serum and urine levels of free DPD (r = 0.08; P = 0.37). In conclusion, urinary-free DPD did not reflect enhanced bone turnover during the time of puberty. Free DPD serum levels are very low, which may be due to rapid clearance via the kidneys.

Acute Disease↗
PubMed1996

Long-term behavior of radiocesium in dairy herds in the years following the Chernobyl accident.

The longterm behavior of 137Cs in milk of a Bavarian farm (farm A) deposited as a consequence of the Chernobyl accident has been followed from April 1986 until August 1994. On the basis of activity measurements in milk and feed, transfer coefficients for the different seasons have been estimated in order to see any changes in transfer behavior (aging effect) of 137Cs with time. The influence of different grazing regimes has been tested by comparison of activity concentrations in milk and pasture grass in one farm (farm A with rotational grazing regime) with that of a nearby farm (farm B with continuous grazing regime) over a complete grazing season by frequent measurements in 1993. Though the farms are located only 4 km apart, have similar soils, and were contaminated to the same extent by the Chernobyl fallout, tenfold lower 137Cs activity concentrations in milk have been observed in farm B. This finding seems to be partly due to the influence of a different grazing intensity.

Animals↗
PubMed1996

Urinary immunoreactive deoxypyridinoline in children and adolescents: variations with age, sex and growth velocity.

The collagen cross-linking compound deoxypyridinoline (DPD) has been shown to be a marker of bone resorption and skeletal growth in children. However, the original method for the determination of total (i.e. free and peptide-bound) DPD (tDPD) in urine samples is technically demanding. The recent development of a simple enzyme-linked immunosorbent assay for the quantification of immunogenic DPD (iDPD) in urine samples might be a more convenient technique. Yet, it is unclear at present whether iDPD is equal to tDPD as an index of bone resorption and skeletal growth. Therefore, using 24-h urines from 144 healthy children and adolescents aged 4-19 years, we established reference ranges for the daily urinary excretion of iDPD. A close correlation was found between the daily urinary excretion of iDPD and tDPD related to body weight (r = 0.87, p < 0.001). In 72 subjects aged 4-18 years, the daily excretion of iDPD normalized to body weight was highly significantly correlated with growth velocity (r = 0.70, p < 0.001). We conclude that the enzyme-linked immunosorbent assay for urinary iDPD appears to provide a good index of bone resorption and growth in healthy children.

Adolescent↗
PubMed1995

Temperature-induced changes in the composition of floatglass surfaces.

Floatglass is an important kind of commercial glass, comprising the main body of modern flat glass used in buildings and vehicles. The stoichiometry of the surface layer differs from that of the bulk and will usually change due to subsequent high-temperature process steps or attack by water or humidity. Glass samples have been investigated by means of ion beam analysis. Using resonant nuclear reaction analysis ((15)N technique), hydrogen concentration profiles have been determined. Profiles of the heavier glass constituents, especially sodium and tin, have been obtained by RBS. Changes in the composition of the floatglass surfaces caused by subsequent temperature treatment (up to 700 ( degrees )C) and by controlled hydration treatment are reported. Possible mechanisms of hydrogen uptake and release are discussed.

Journal Article↗
PubMed1995

Increased urinary excretion of collagen crosslinks in girls with Ullrich-Turner syndrome.

Skeletal abnormalities and "osteoporosis" are frequent features of Ullrich-Turner syndrome (UTS), but their cause remains largely unknown. In this study, we compared the urinary excretion of hydroxyproline (OHP), pyridinoline (PYD) and deoxypyridinoline (DPD) in 28 girls (bone age 3.5-11.0 years, mean 7.4 years) with UTS and 30 healthy prepubertal children (chronological age 3.9-10.9 years, mean 7.6 years). Expressed relative to the square of the height, the excretion of both collagen crosslinks was significantly higher in UTS than in controls (23.4% for PYD, 33.6% for DPD, p < 0.05). In contrast, no significant difference was found for OHP. The molar PYD/DPD ratio was significantly lower in UTS children than in controls (mean (+/- SD) 3.4 (+/- 0.41) versus 3.8 (+/- 0.55); p = 0.004). While the higher excretion of collagen crosslinks reflects enhanced bone resorptive activity in UTS, the lower PYD/DPD ratio might be due to structural alterations in collagen.

Adolescent↗
PubMed1995

Urinary excretion of galactosyl-hydroxylysine is a marker of growth in children.

Galactosyl-hydroxylysine (Gal-Hyl) is the predominant product of the posttranslational glycosylation of skeletal collagen. Urinary Gal-Hyl excretion is regarded as a marker of bone resorption in adults, but little information is available on the validity of this parameter in pediatric age groups. Using 24-h urine samples from 88 healthy children and adolescents ages 4-18 yr, reference ranges were established for this age group, and values were compared with measurements in children with overt GH deficiency (n = 14) or Ullrich-Turner syndrome (n = 21). When expressed relative to body weight (Gal-Hyl/wt), urinary Gal-Hyl excretion was 3.2 to 4.7 times higher in subjects 4-16 yr of age than in adults. Highest values were observed in very young children and during the pubertal growth spurt. In the total population, urinary Gal-Hyl/wt was closely related to growth velocity (r = 0.72) and significantly correlated with the urinary excretion of both hydroxyproline (r = 0.74) and deoxypyridinoline (r = 0.88; P < 0.001 each). Urinary Gal-Hyl/wt was significantly lower in children with GH deficiency or Ullrich-Turner syndrome than in healthy children (P < 0.001 each). The urinary excretion of Gal-Hyl was significantly correlated with growth velocity in GH-deficient children (r = 0.69; P = 0.004) but not in patients with Ullrich-Turner syndrome. In the latter, the increase in urinary Gal-Hyl excretion after 3 months of treatment with recombinant human GH correlated significantly with the increase in growth velocity after 12 months of treatment (r = 0.76; P = 0.002). We conclude that the urinary excretion of Gal-Hyl is a valid and potentially useful index of skeletal growth in children.

Adolescent↗
PubMed1994

Urinary excretion of hydroxy-pyridinium cross-links of collagen reflects skeletal growth velocity in normal children.

Two new markers of bone resorption, the collagen cross-linking amino acids pyridinoline (PYD) and deoxypyridinoline (DPD), were measured in 24-h urine collections from 88 healthy children (45 females, 43 males; age 4 to 18 years) and 17 adults. Normal values for pediatric use were established for these parameters. Related to daily excretion of creatinine PYD and DPD were about 3 to 6 fold higher in the pediatric groups than in adults. The collagen cross-links showed a highly significant correlation to the urinary excretion of hydroxyproline (OHP): r = 0.65 for PYD and r = 0.60 for DPD (p < 0.001). Both collagen cross-links and OHP excretion related to creatinine were significantly correlated to growth velocity (r = 0.67, 0.62 and 0.51 for PYD, DPD and OHP respectively; p < 0.001 in each case). PYD and DPD may be useful for the monitoring of growth in children.

Adolescent↗
PubMed1994

Distribution of deoxyribonuclease I in rat tissues and its correlation to cellular turnover and apoptosis (programmed cell death).

The expression of deoxyribonuclease I (DNase I) in various rat tissues was screened by use of a cDNA-probe of rat parotid DNase I and monospecific polyclonal antibodies. High amounts of DNase I-specific mRNA were found in the parotid gland, kidney and small intestine. Homogenates of these organs also contain elevated levels of DNase I-specific DNA-degrading activity as verified by the zymogram technique and immunoblots. Affinity-purified polyclonal antibodies against rat parotid DNase I were employed in an immunohistochemical study of the cellular distribution of DNase I antigen in rat parotid gland, kidney, small intestine, and a number of stratified epithelia. In the parotid gland the DNase I antigenicity was found to be confined to the secretory cells. Within these cells the secretory granules exhibit the highest immunoreactivity. In contrast, within the small intestine and stratified epithelia we found a preferential localization and concentration of DNase I in cells prone to undergo apoptosis (programmed cell death), i.e., within the migrating enterocytes present at the villar tips and the keratinocytes above the basal cell layer. Within the kidney, the cells lining the convoluted distal tubules and collecting ducts exhibit strong DNase I immunoreactivity which was found to often localize perinuclearly. The cells exhibiting chromatin fragmentation were identified on paraffin-embedded sections by in situ end-labeling of free 3'-OH-ends of cleaved DNA using fluorescent dATP or dUTP and terminal transferase. It was found that only a small fraction of the DNase I positive cells showed signs of apoptotic chromatin degradation. Thus only a few enterocytes at the uppermost villar tips and very few keratinocytes underneath the keratinized layer were in situ end-labeled, i.e., exhibited a high concentration of fragmented DNA. This result is taken as evidence that these cells express DNase I in advance of their apoptotic death and furthermore that the actual apoptosis is a rapid process only detectable in a few cells. In contrast, no in situ end-labeled apoptotic nuclei were detected in rat kidney provided that care was taken to rapidly excise and fix this organ.

Amino Acid Sequence↗
PubMed1989

Recognition of the retrograde reaction in motoneurons using an image analysing system.

An automatic procedure is described which allows recognition of sectional profiles of alpha-motoneurons of the facial nucleus of the rat. The system is able to distinguish nucleus and nucleolus from the cytoplasm of the nerve cell profile and to characterize those structures by suitable parameters. The region of the nucleus of the facial nerve (FNN) has been measured 7 days after unilateral partial nerve transsection. Based on the resulting data a multivariate analysis was performed to distinguish between normal and retrograde reacting cells. It is shown that this automatic cell characterisation technique is highly sensitive and reliable. The data were used to describe comprehensively the retrograde reaction of the cell.

Animals↗
PubMed1986

A preliminary outcome study of a community group treatment programme for emotionally disturbed adolescents.

The treatment of adolescents with psychiatric disturbance remains a highly unsuccessful area. Empirical research is limited and treatment decisions are often based on theoretical bias rather than proven results. This study reports on the results of a multivariate analysis of pre- and post-individual and family measures on patients in a community based day and evening programme. The programme utilized a broad range of treatment modalities including group and family therapy and chemotherapy. An accredited educational programme was also provided to the patients attending the day programme. The results of this study showed that adolescents were referred to either the day or evening programme components based on level of acting out behaviour rather than on DSM III diagnosis. Adolescents reported significant positive changes at post testing in all areas, but this improvement was not endorsed by parents. Although therapists perceived considerable improvement in their families after treatment, this improvement did not show up on the family assessment measure chosen. The findings of the study endorse the need for further empirical research in adolescent treatment and underscores the fallacy of relying on anecdotal evidence to report treatment results. Questions are raised as to the operational usefulness of the present DSM III criteria in making treatment decisions and the validity of associating individual dysfunction with family dysfunction. Some question as to the sensitivity of the family measure used was also raised. The study outlined strengths and weaknesses in the present treatment programme and underscored the importance of further evaluative research, if the treatment of adolescents with psychiatric disturbance is to become successful.

Adolescent↗
PubMedDate not supplied

Bone growth in length and width: the Yin and Yang of bone stability.

Bone growth in length is primarily achieved through the action of chondrocytes in the proliferative and hypertrophic zones of the growth plate. Longitudinal growth is controlled by systemic, local paracrine and local mechanical factors. With regard to the latter, a feedback mechanism must exist which ensures that bone growth proceeds in the direction of the predominant mechanical forces. How this works is unknown at present. Bone growth in length is detrimental to bone stability, but this effect is counteracted by concomitant bone growth in width. This occurs through periosteal apposition, which is the responsibility of periosteal osteoblasts. The action of these cells is mainly controlled by local factors, with modulation by systemic agents. According to the mechanostat theory, periosteal apposition is regulated by mechanical requirements. An alternative model, called sizostat hypothesis, maintains that a master gene or set of genes regulate bone growth in width to reach a pre-programmed size, independent of mechanical requirements. The virtues of these two hypotheses have been the subject of much discussion, but experimental data are scarce. Future research will have to address the question how periosteal bone cells manage to integrate mechanical, hormonal and other input to shape bones that are as strong as they need to be.

Animals↗
PubMedDate not supplied

Material matters: a mechanostat-based perspective on bone development in osteogenesis imperfecta and hypophosphatemic rickets.

This perspective paper presents a hypothesis that links abnormalities of bone material with densitometric findings in two congenital metabolic bone disorders, osteogenesis imperfecta type I (OI) and X-linked hypophosphatemic rickets (XLH). Analyses of iliac bone samples from OI patients have shown that material bone density is elevated and that the bone material is abnormally stiff in this disorder. Therefore, a given mechanical load on an OI bone will generate a smaller than normal deformation. This in turn should lead osteocytes, the putative mechanosensing cells, to systematically underestimate the prevailing mechanical forces. According to the mechanostat model, bone strength should then be adapted to the underestimated mechanical loads, which means that bone architecture and mass remain below requirements. Available densitometric studies are in accordance with this hypothesis. In XLH, a mild mineralization defect persists despite treatment. This mineralization defect should lead to soft bone material. In analogy to the above model for OI, mechanical loads should be overestimated, resulting in increased densitometric parameters of bone strength. Indeed, lumbar spine areal bone mineral density is usually elevated in such patients.

Biomechanical Phenomena↗
PubMedDate not supplied

Effect of a single botulinum toxin injection on bone development in growing rabbits.

Intramuscular injections with botulinum toxin A (BTX-A) lead to a rapid decrease in muscle mass and force, but the effect of this drug on bone development is unclear. In the present pilot study we evaluated the effect of a one-time injection of BTXA in growing rabbits. Twelve young (weight 1.5 kg) New Zealand rabbits were randomly assigned to receive either BTX-A (total dose 8 units per kg body weight) or sodium chloride 0.9% injections into the left quadriceps and gastrocnemius muscles. Both groups continued to gain weight in a similar manner following the injection. However, when the animals were sacrificed at five weeks after the injection, the group receiving BTX-A had a significant deficit (of 10%) in gastrocnemius muscle mass on the injected side, whereas no significant side-difference was found for the quadriceps. BTX-A injections did not affect the length of the tibia. Nevertheless, bone mineral content of the whole tibia, as measured by dual-energy X-ray absorptiometry, was 7% lower in the BTX-A injected side than on the contralateral side. Peripheral quantitative computed tomography showed that this bone mass deficit was larger in the metaphysis than in the epiphysis or diaphysis. In the diaphysis, the bone mass deficit was due to a reduction in cross-sectional bone dimensions, which equally affected the cross-section of the entire bone, the cortical compartment and the marrow space. BTX-A injections did not have a detectable effect on cortical bone mineral density. The bone mass deficit in the diaphysis thus appeared to be caused by a lack of periosteal bone apposition rather than increased endocortical or intracortical resorption. These preliminary data suggest that intramuscular BTX-A injections can have a deleterious effect on the development of bones that are loaded by the injected muscles.

Animals↗