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Discrete and continuous dynamical systems : DCDS / S 13(4), ⅰ-ⅲ (2020). doi:10.3934/dcdss.20204i special issue: "Dynamical systems and geometric mechanics: A special issue in Honor of Jürgen Scheurle", Published by American Institute of Mathematical Sciences, Springfield, Mo.

Resume Objectifs Nous avons deja demontre une diminution de la densite osseuse et une augmentation de l’incidence de la carence en 25-hydroxy vitamine D3 (25-OH D3) chez les adultes ayant une neurofibromatose 1 (NF1) compares aux sujets temoins. La vitamine D3 est un complement bon marche, sur et efficace dans la population generale mais son importance chez les NF1 n’a pas ete demontree. Cette etude etudie les effets therapeutiques potentiels de la vitamine D3 sur la densite minerale osseuse (DMO) chez des patients ayant une NF1 avec carence en vitamine D3. Methodes Nous avons mesure la 25-OH D3, l’hormone parathyroidienne, la calcemie, la phosphatase alcaline osseuse, la concentration urinaire de deoxypyridinoline et la DMO chez 35 adultes ayant une NF1. Dix-neuf patients recurent une supplementation en vitamine D3 pendant deux ans, six patients une supplementation pendant un an et dix patients ne recurent pas de supplementation. La supplementation fut administree a la dose permettant de maintenir le taux de 25-OH D3 au-dessus de 30 μg/L. La DMO fut mesuree a un an et deux ans et l’evolution biochimique du metabolisme osseux fut mesuree au moins tous les six mois durant le traitement. Resultats Les sujets traites avaient, de facon significative, une reduction de leur perte de DMO mesuree par T score a la hanche (p = 0,011) et au rachis lombaire (p = 0,022). L’effet sur la DMO a la hanche fut apparent a un an, comparativement a l’inclusion (p = 0,002) et fut plus important a deux ans, comparativement a un an (p = 0,002). Conclusions La supplementation en vitamine D ameliore la DMO chez les patients ayant une NF1. Des etudes ulterieures sont necessaires pour elucider le mecanisme responsable de la reduction de la DMO chez les patients porteurs d’une NF1.

This study addresses the interactions of coffee storage proteins with coffee-specific phenolic compounds. Protein profiles, of Coffea arabica and Coffea canephora (var robusta) were compared. Major Phenolic compounds were extracted and analyzed with appropriate methods. The polyphenol-protein interactions during protein extraction have been addressed by different analytical setups [reversed-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS), and Trolox equivalent antioxidant capacity (TEAC) assays], with focus directed toward identification of covalent adduct formation. The results indicate that C. arabica proteins are more susceptible to these interactions and the polyphenol oxidase activity seems to be a crucial factor for the formation of these addition products. A tentative allocation of the modification type and site in the protein has been attempted. Thus, the first available in silico modeling of modified coffee proteins is reported. The extent of these modifications may contribute to the structure and function of "coffee melanoidins" and are discussed in the context of coffee flavor formation.

Inoculated or non-inoculated naked barley and emmer cultivars were investigated with regard to their influence on phenolic acid profiles and their arabinoxylan content. Two groups of phenolic compounds were differentiated-methanol- soluble and hydrolyzable covalent-bound phenolic compounds. Chromatographic methods were applied for their analysis. The results showed ferulic acid as the predominant phenol in both total and covalent-bound fractions. The inoculation significantly reduced the ferulic acid content within a range of 5.6-6.6% in the two cereals and all their cultivars. Naked barley cultivars additionally contained the flavonoid catechin in the soluble fraction. The innoculation led here to a significant increase in the catechin content of about 4.5%. These results document an induction of the synthesis of catechin in naked barley after artificial Fusarium infection, whereas the ferulic acid content declined.

Background The Risedronate and Alendronate (REAL) cohort study provides unique comparative effectiveness data for real world bisphosphonate treatment of osteoporosis. Objective The objective of this analysis was to assess the cost-effectiveness of risedronate compared to generic alendronate in Germany applying the REAL effectiveness data. Materials and Methods A validated Markov model of osteoporosis was populated with REAL effectiveness data and German epidemiological, cost, and utility data. To estimate the impact of therapy on hip fractures, costs, and quality adjusted life years (QALYs), the analysis included women ≥65 years, treated with risedronate or alendronate and followed for 4 additional years. Country-specific data included population mortality, fracture costs, and annual drug costs, using a German social insurance perspective. Costs and outcomes were discounted at 3%. A differential hip fracture relative risk reduction of 43% was applied to risedronate vs. alendronate. Results The model predicted that treatment with risedronate would result in fewer hip fractures and more QALYs at a reduced cost (savings of €278 per treated woman) compared to treatment with generic alendronate. Sensitivity analysis assuming 2 years of treatment and equivalence of effect after 1 year show cost savings as well (€106 per treated woman). Discussion Whereas previous economic evaluations involving bisphosphonates have mainly relied on efficacy data from noncomparative clinical trials, this study's strength is in the use of comparative effectiveness data from one data source. The magnitude of the cost savings observed were sensitive to alternative assumptions regarding treatment duration, therapy discontinuation and cost of generic alendronate. Conclusions Based on "real world" data the analysis supports the first line use of risedronate for the treatment of osteoporotic women in Germany.

Scope Flavan-3-ols are abundant polyphenols in human nutrition and are associated with beneficial health effects. The aim of this study was to comparatively investigate the metabolic fate of (-)-epicatechin, procyanidin B1, and polymeric procyanidins in a randomized cross-over study in humans. Methods and results Parent compounds, conjugates, and microbial metabolites were determined in plasma, urine, and faeces by HPLC-MS and GC-MS/MS. Glucuronidated, sulfated, and methylated (-)-epicatechin and 5-(3′,4′-dihydroxyphenyl)-valerolactone were the dominant metabolites in blood and urine. In addition, minor amounts of procyanidin B1 and 4-hydroxy-5-(3′,4′-dihydroxyphenyl)valeric acid and their conjugated metabolites were detected. The formation of 5-(3′,4′-dihydroxyphenyl)-valerolactone and 4-hydroxy-5-(3′,4′-dihydroxyphenyl)valeric acid varied largely between individuals as well as with the degree of polymerization of flavan-3-ols. Monomer units were not detectable in plasma or urine after procyanidin B1 and polymeric procyanidin intake. No correlation was found between the intake of flavan-3-ols and the occurrence of phenolic acids in blood and urine or the phenolic compound profiles in faeces. Conclusion In addition to conjugated metabolites derived from the absorption of monomeric flavan-3-ols, 5-(3′,4′-dihydroxyphenyl)-valerolactone represents an important in vivo metabolite of (-)-epicatechin and procyanidin B1 produced by the gut microbiota.

Background. In primary hyperoxaluria type I (PH 1), hepatic overproduction of oxalate leads to its deposition in various organ systems including bone (oxalosis). To evaluate skeletal status non-invasively in PH 1 we measured bone mineral density (BMD). Methods. Peripheral quantitative computed tomography of the distal radius was performed in 10 children with PH 1 (mean chronological age 9±3.1, mean skeletal age 8.3 ±3.0 years): seven were on conservative treatment (CT) including one patient after pre-emptive liver transplantation (PH1-CT) and three were studied with end-stage renal disease on peritoneal dialysis (PH1-ESRD). Results. Mean trabecular bone density (TBD) was significantly increased in PH1-ESRD compared with both age-matched healthy and uraemic controls (65227 vs 168±63 and 256±80 mg/cm 3 ; P < 0.002 and P < 0.007, respectively), while cortical bone density (CBD) was elevated to a lesser degree (517±23 vs 348±81 vs 385±113 mg/cm 3 ; P < 0.02 and P < 0.04, respectively). In PH 1, CBD and, even more so, TBD were significantly correlated with serum creatinine (r = 0.91 and r = 0.96, P < 0.0001, respectively) and plasma oxalate levels (r = 0.86 and r = 0.94, P < 0.001 and P < 0.0001, respectively). In children with PH I and normal glomerular function, both CBD and TBD were comparable with healthy controls. Conclusion. These preliminary data suggest that in PH 1 BMD is significantly increased in ESRD, probably due to oxalate disposal. Measurement of BMD may be a valuable and non-invasive tool in determining and monitoring oxalate burden in this disorder.

An energy-controlled study on a Western diet composed of 45% fat, 40% carbohydrate and 15% protein by energy was carried out. The study consisted of four test phases having a length of 9 days in each case, where 8 healthy free- living subjects were adjusted to individual energy requirements at maintenance level. Between the tests, wash-out phases of 4-5 months were inserted to avoid adaptation effects. By using a standard breakfast of constant composition, satiety was evaluated by applying the concept of categorical comparison, which was based on the common fact, that the perception between two meals is changed and usually a set of sensations can be discriminated. These were termed very full and full (just after finishing a meal), appetite and hungry (just before the next meal). These sensations were used as categories on a categorical scale. The evaluation of satiety was performed such that on each day of the four test phases the subjects had to select over a period of 4 h every 30 min one category out of the four, what corresponded to the individual sensation at that time. This procedure was followed by a mathematical treatment of data such that the individual judgements were transformed into a numerical system. As a result, the time course of satiety was available characterizing the time-dependent change of the interoception after consuming the test meal. Using this concept highly reliable results were obtained as demonstrated by the comparison of the four test series.

The equations of motion of an ideal incompressible liquid drop trapped between two parallel plates under the influence of surface tension and adhesion forces are studied. A main result of this paper is the proof that the equations of motion can be written in Hamiltonian form formula here Here [Dscr ] denotes a class of real-valued functions on the phase space [Nscr ] of the system and the Hamiltonian H ∈[Dscr ] is the energy function of the system. This allows the derivation of an equation for the (dynamic) contact angle, in which the free fluid surface meets the plates. The behaviour of the dynamic contact angle is a point of great controversy in the capillarity literature and the derivation confirms one of the existing models. In the second part of the paper, which can be read independently, existence and stability questions for rigidly rotating drops are dealt with. The existence of solutions to the equations of motion that describe rotationally symmetric drops which rotate rigidly between the plates with constant angular velocity is proved. These solutions can be regarded as relative equilibria of a mechanical system with symmetry. Using ideas of the energy-momentum method of Lewis, Marsden and Simo, a stability criterion for this kind of motion is provided. To derive this criterion, the second derivative of the so-called augmented energy functional at the relative equilibrium in directions which are transversal to the group orbit of this equilibrium is studied. The stability criterion is applied to rigidly rotating drops of cylindrical shape. These represent solutions to the equations of motion in the case that no adhesion forces act along the plates. The result extends previous work of Vogel and Lewis.

We show that the configuration space of an inviscid incompressible liquid bridge connecting two parallel plates has the structure of a Hilbert manifold. To construct this manifold structure we follow the general strategy of Ebin and Marsden [Groups of diffeomorphisms and the motion of an incompressible fluid, Ann. Math. 92 (1970) 102–163], where a manifold structure has been introduced for an inviscid incompressible fluid which completely fills a domain with smooth boundary. The fact that the liquid bridge has a non-smooth boundary requires extra considerations. In particular, we show how the use of Hodge theory as in the above mentioned reference can be avoided in the case of liquid bridges.

We consider a rotating inviscid liquid drop trapped between two parallel plates. The liquid–air interface is a free surface and the boundaries of the wetted regions in the plates are also free. We assume that the two contact angles at the plates are equal. We present drop shapes that generalize the catenoids, nodoids and unduloids in the presence of rotation. We describe profile curves of these drops and investigate their stability to three-dimensional perturbations. The instabilities are associated with degeneracies of eigenvalues of the corresponding Hamiltonian linear stability problem. We observe that these instabilities are present even in the case when the analogue of the Rayleigh criterion for two-dimensional stability is satisfied.

We consider a mathematical model that describes the motion of an ideal fluid of finite volume that forms a bridge between two fixed parallel plates. Most importantly, this model includes capillarity effects at the plates and surface tension at the free surface of the liquid bridge. We point out that the liquid can stick to the plates due to the inner pressure even in the absence of adhesion forces. We use both the Hamiltonian structure and the symmetry group of this model to perform a bifurcation and stability analysis for relative equilibrium solutions. Starting from rigidly rotating, circularly cylindrical fluid bridges, which exist for arbitrary values of the angular velocity and vanishing adhesion forces, we find various symmetry-breaking bifurcations and prove corresponding stability results. Either the angular velocity or the angular momentum can be used as a bifurcation parameter. This analysis reduces to find critical points and corresponding definiteness properties of a potential function involving the respective bifurcation parameter.

A suitable vehicle for integration of bioactive plant constituents is proposed. It involves modification of proteins using phenolics and applying these for protection of labile constituents. It dissects the noncovalent and covalent interactions of beta-lactoglobulin with coffee-specific phenolics. Alkaline and polyphenol oxidase modulated covalent reactions were compared. Tryptic digestion combined with MALDI-TOF-MS provided tentative allocation of the modification type and site in the protein, and an in silico modeling of modified beta-lactoglobulin is proposed. The modification delivers proteins with enhanced antioxidative properties. Changed structural properties and differences in solubility, surface hydrophobicity, and emulsification were observed. The polyphenol oxidase modulated reaction provides a modified beta-lactoglobulin with a high antioxidative power, is thermally more stable, requires less energy to unfold, and, when emulsified with lutein esters, exhibits their higher stability against UV light. Thus, adaptation of this modification provides an innovative approach for functionalizing proteins and their uses in the food industry.

Objectives We have previously demonstrated reduced bone density and an increased incidence of 25-hydroxy vitamin D3 (25-OH D3) deficiency in adults with neurofibromatosis 1 (NF1) compared to healthy controls. Vitamin D3 is a cheap, safe, and effective supplement in the general population, but its value in NF1 patients has not been demonstrated. This study investigates the therapeutic potential of oral vitamin D3 on bone mineral density (BMD) in NF1 patients with vitamin D3 deficiency. Methods We measured serum 25-OH D3, parathyroid hormone, calcium, and bone alkaline phosphatase concentrations, urinary deoxypyridinoline concentrations, and BMD in 35 adults with NF1. Nineteen patients received vitamin D3 supplementation for 2 years, six patients received supplementation for 1 year and 10 patients received no supplementation. Supplementation was administered in a dose that maintained the serum 25-OH D3 level above 30 μg/l. BMD was measured again at 1 and 2 years, and biochemical assessments of bone metabolism were measured at least every half year during therapy. Results Treated subjects had significantly reduced loss of BMD, as measured by T score at the hip (p = 0.011) and lumbar spine (p = 0.022). The effect on hip BMD was apparent at 1 year in comparison to baseline (p = 0.02) and was greater at 2 years in comparison to measurements at 1 year (p = 0.02). Conclusions Vitamin D3 supplementation improves BMD in adult NF1 patients. Further studies are needed to elucidate the mechanisms responsible for reduced BMD in NF1 patients.

Effects of commercial fat replacers on rheological properties of emulsions have been studied under a second-order design. The corresponding functions of regression have been calculated to describe the measured effects mathematically. On the basis of a figured three-dimensional plan of response, combinations of variables (fat, fat replacer, water) could be determined showing a similar consistency to the corresponding full-fat foodstuff.

Bei der hydrothermischen Behandlung von Weizenstarke in Gegenwart von Bakterien-α-Amylase wird auf die Gewinnung der modifizierten Reststarke bei maximaler Verschiebung der durch DSC-Messung bestimmten Quellungstemperatur Tmax und einer hohen Ausbeute orientiert. Die Temperung der kornformigen Starke in Gegenwart von Enzym ergibt bei Temperaturen unterhalb der Quellungstemperatur (50°C) dieselbe Tmax-Verschiebung wie die Temperung in Wasser. Auf Grund des laufenden enzymatischen Abbaus von angequollenem Material konnen jedoch hohere Reaktionstemperaturen angewandt werden, wodurch die Temperung effektiver wird. Der gebildete Maltosesirup verlangsamt die Tmax-Verschiebung und schutzt gleichzeitig das Starkekorn. Weizenstarke kann mit einer Ausbeute von 70% und einer Tmax-Verschiebung von 8K innerhalb von 24h getempert werden. Hydrothermal Treatment of Starch in the Presence of α-Amylase. Part 2: Effect of a Hydrothermal Enzymatic Modification on the Swelling Temperature of Wheat Starches. The hydrothermal treatment of wheat starch in the presence of bacterial-α-amylase is directed to the production of modified residual starches with a maximal shift of swelling temperature Tmax (measured by DSC) at high yields. The annealing of granular starch at temperatures below the swelling temperature (50°C) in presence of α-amylase gives no difference regarding the shift of Tmax. Because of the hydrolysis of swollen material it is possible to use higher reaction temperatures and the process becomes more effective. The formed maltose syrup retards the shift of Tmax and protects the granules. Within 24h wheat starch can be modified with a yield of 70% and a shift of Tmax of 8K.

Isoflavones are thought to be biologically active components in soy that play a role in the prevention of chronic diseases including cancer. How isoflavones may mediate their beneficial effects has not yet been fully established. Potential mechanisms of cellular action of isoflavones may include their ability to modulate gene expression and the activity levels of enzymes involved in antioxidant defence and the metabolism of xenobiotics including NAD(P)H (Nicotinamide-adenine-dinucleotide-phosphate) quinone oxidoreductase 1 (NQO1) and glutathione S-transferase (GST). Although there is increasing evidence from cell culture studies that genistein, the major isoflavone present in soy, may regulate the expression of genes encoding for phase II and antioxidant enzymes, little is known about its effect in vivo. Feeding rats over 3 weeks with semisynthetic diets enriched with genistein (2 g/kg) significantly increased both the hepatic mRNA and activity levels of NQO1. The total GST activity did not change in response to dietary genistein supplementation, whereas the mRNA levels of individual GST isoenzymes were differentially modulated. The hepatic mRNA level of Gsta2 (class alpha 2) was significantly increased whereas the mRNA levels of Gstm2 (class mu 2) and Gstp1 (class pi 1) were significantly lowered due to genistein supplementation. The protein level of Nrf2 (Nuclear factor E2-related factor 2), a transcription factor involved in the regulation of phase II enzymes, was not altered by dietary genistein. Furthermore, genistein did not affect the hepatic enzyme activity of the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) or liver lipid peroxidation and glutathione levels. The induction of NQO1 may be one mechanism by which dietary genistein improves the capacity of the liver to detoxify carcinogens.

Osteoporotic patients with insufficient calcium intake and/or vitamin D insufficiency need adequate calcium and vitamin D supplementation with their bisphosphonate treatment. However, consistent intake and, therefore, the effectiveness of calcium/vitamin D supplementation may be impaired by several factors in the individual patient: low prescription rate or lack of advice to purchase calcium/vitamin D; reduced compliance because of the complexity of the regimen; or incorrect intake. There is a need to provide patients with a better way of taking bisphosphonate treatment with their calcium/vitamin D supplementation. To this end, a fixed-combination pack to help patients take the combination of bisphosphonate, calcium and vitamin D correctly and regularly has been developed.To evaluate patients' understanding of administration instructions, preferences and their perceptions of compliance, convenience and completeness of a fixed-combination pack of bisphosphonate, calcium and vitamin D compared with those associated with separate packs.The new monthly fixed-combination pack of bisphosphonate, calcium and vitamin D contains four weekly boxes. Each box contains a blister pack with one swallowable risedronate 35 mg film-coated tablet and six sachets of calcium/vitamin D effervescent granules (calcium 1000 mg and vitamin D(3) [colecalciferol] 880 IU) for dissolution in water as an oral solution, together constituting 1 week of therapy, accompanied by a patient information leaflet. Two quantitative patient research survey studies were conducted using standard questionnaires in face-to-face interviews with 400 postmenopausal women in several French cities. Participants were given the combined pack and two separate packs (risedronate 35 mg once weekly and calcium/vitamin D effervescent granules in sachets). In the first study, participants' understanding of administration instructions and preferences were evaluated. In the second study, participants' perception of compliance, convenience and completeness of the new combination pack of risedronate 35 mg plus calcium/vitamin D compared with two separate packs were evaluated.Participants asked about the combined pack answered a significantly higher proportion of questions about intake instructions correctly (80.3%) than participants asked about the two separate packs (70.7%) [p = 0.0004]. The combined pack was preferred by 72% of participants (p0.0001) for several reasons. Compared with separate packs, the combined pack was considered easier to use by 63% and easier to remember to use by 67% of participants. Participants believed that use of the combined pack would be more likely to help them take their bisphosphonate regularly (66%) and correctly (67%), and to take their calcium/vitamin D supplementation more regularly and correctly (68%), than use of separate packs. Seventy percent of participants believed that use of the combination pack would help them to not forget to take calcium/vitamin D supplementation.Use of the fixed-combination pack of risedronate 35 mg plus calcium/vitamin D once weekly could increase the likelihood that postmenopausal osteoporotic patients will receive a complete bisphosphonate, calcium and vitamin D therapy course and is likely to enhance correct intake of combination therapy. Use of this fixed-combination product will provide patients with a tool for improving adherence to recommended osteoporosis therapy and optimize the effectiveness of such treatment.

Objective: To determine participant preference for weekly versus monthly bisphosphonate therapy for osteoporosis after being informed about differences in fracture efficacy. Design: 20‑minute, semi-structured, face-to-face or telephone interviews. Two bisphosphonate choices were presented on the basis of block randomization: weekly therapy with proven efficacy to reduce fracture risk at the spine and hip, or monthly therapy with proven efficacy to reduce fracture risk at the spine but not the hip. Subjects: Women from the UK, Germany, France, Spain and Italy, with postmenopausal osteoporosis and aged ≥ 55 years. Fifty percent were currently taking a weekly bisphosphonate; 50% had no history of taking any bisphosphonate. Measures: An efficacy rating scale and an intention-touse rating scale were developed for this study. The primary endpoint was preference for weekly or monthly therapy. Reasons for preference were recorded. Results: A preference was recorded for 1248 women (1253 were recruited). More women preferred weekly to monthly therapy (82% vs. 18%, respectively; p < 0.001). Among women who preferred weekly therapy, efficacy was the most commonly cited reason (65%). Ninetytwo percent of the total cohort rated the efficacy of the weekly therapy as ‘excellent/good’ versus 38% for monthly ( p < 0.001). Sixty-nine percent intended to use weekly bisphosphonates compared with 34% for monthly ( p < 0.001). Conclusions: When informed about differences in fracture efficacy in weekly and monthly bisphosphonates, a significantly greater proportion (82%) of women preferred a weekly bisphosphonate with proven fracture efficacy at the spine and hip over a monthly bisphosphonate with proven fracture efficacy only at the spine.

Bovine serum albumin (BSA) was modifed by covalent attachment of chlorogenic acid using different concentrations at pH 9. The derivatization was accompanied by a reduction of lysine, cysteine and tryptophan residues. The isoelectric points were shifted to lower pH values and formation of high molecular weight fractions was noted. The structural changes were studied using circular dichroism, differential scanning calorimetry (DSC), intrinsic fluorescence, and binding of anilinonaphthalenesulfonic acid. The results showed that the content of alpha-helix decreased with a parallel increase in unordered structures with higher degrees of derivatization. DSC revealed a decrease in both denaturation temperature and enthalpy. Surface hydrophobicity declined, indicating that hydrophilic regions were exposed on the molecular surface. Proteolytic digestion showed that, at a lower degree of derivatization,the tryptic degradation was most adversely effected, whereas the peptic digestion declined with increasing modification. A trypsin inhibitory effect of the breakdown products released from derivatized BSA was also observed.

This paper uses Hamiltonian structures to study the problem of the limit of three-dimensional (3D) elastic models to shell and rod models. In the case of shells, we show that the Hamiltonian structure for a three-dimensional elastic body converges, in a sense made precise, to that for a shell model described by a one-director Cosserat surface as the thickness goes to zero. We study limiting procedures that give rise to unconstrained as well as constrained Cosserat director models. The case of a rod is also considered and similar convergence results are established, with the limiting model being a geometrically exact director rod model (in the framework developed by Antman, Simo, and coworkers). The resulting model may or may not have constraints, depending on the nature of the constitutive relations and their behavior under the limiting procedure.

Hier sind Krankheitsbilder abzuhandeln, die nicht ohne weiteres zu klinisch erkennbaren Skelettveranderungen fuhren und somit nicht zu den eigentlichen endokrinen und metabolischen Osteopathien gehoren.

Die Osteoporose wird als ein Zustand definiert, bei dem die Knochenmasse bzw. das absolute Knochenvolumen gegenuber der alters- und geschlechtsentsprechenden Norm vermindert ist (Albright u. Reifenstein, 1948; Frost, 1966; Kuhlencordt, 1976; Pommer, 1885). Diese Definition beinhaltet keine Aussage uber die physikalische oder biochemische Qualitat der Knochensubstanz selbst. Zu ihrer quantitativen Untersuchung stehen eine Reihe von biochemischen und biophysikalischen Methoden zur Verfugung (Baud u. Pouezat, 1975; Dulce, 1975), mit denen sich in Einzelfallen verschiedene Normabweichungen nachweisen lassen (Baud u. Mitarb., 1976; Dulce, 1975). Bei der primaren Osteoporose haben sich jedoch bisher keine einheitlichen bzw. fur diese Osteopathie charakteristischen Befunde ergeben.

Wahrend das Skelett bei den Wirbellosen ausschlieslich bindegewebiger Natur ist, tritt bei den Haien erstmals verkalkter Knorpel auf (Tabelle 1). Dabei wird der Kalziumstoffwechsel auser durch Membranphanomene auch durch eine Mineralkomponente mit Apatitstruktur und durch das Hormon Calcitonin reguliert. Die Knochenfische als Ubergang zu den hoher entwickelten Spezies verfugen bereits uber ein knochernes Skelett, das allerdings ausschlieslich auf knorpeliger Basis gebildet wird. Bei diesen Tieren kommt als weiteres Hormon zu dem bereits genannten Calcitonin das D-Hormon bzw. die D-Metaboliten hinzu. Die Kalziumkonzentration im Serum liegt bei den Wirbellosen und Haien noch bei rund 40mg% bzw. 20 mg%, wahrend sie sich bei den Knochenfischen — wie bei allen hoheren Entwicklungsstufen — um 10 mg% bewegt und damit gegenuber der umgebenden Meerwasserkonzentration deutlich reduziert ist.

Gegenuber dem im anglo-amerikanischen Schrifttum heute noch ublichen Begriff der „metabolic bone diseases“ bevorzugen wir von endokrinen und metabolischen Osteopathien zu sprechen, da uns vom heutigen Standpunkt die Bezeichnung metabolische Osteopathie nicht umfassend genug erscheint. Die endokrinologische Forschung hat inzwischen auf den Gebieten der Nebenschilddrusen und des Parathormons, sowie des Vitamin D-Stoffwechsels zu der Erkenntnis gefuhrt, das ein Grosteil der „metabolic bone diseases“ entweder eine reine endokrine Atiologie hat, wie etwa der primare Hyperparathyreoidismus, oder pathophysiologisch vorwiegend endokrin zu definieren ist, wie z. B. die renale Osteopathie. Danach erscheint es uns nur folgerichtig, sowohl von endokrinen (Abb. 12) als auch von metabolischen Knochenerkrankungen zu sprechen, wodurch der Begriff der metabolischen Osteopathien auf die nicht endokrinen Krankheitsbilder eingeengt werden sollte. Hier liese sich beispielsweise der Phosphatdiabetes nennen, solange keine D-Hormonstorung bewiesen ist.

Dieses Krankheitsbild ist ein typisches Beispiel einer lokalisierten Knochenerkrankung und wurde erstmalig 1877 als Ostitis deformans von dem englischen Chirurgen Paget beschrieben, der einen entzundlichen Prozes des Knochens annahm. Nachdem zwischenzeitlich verschiedene Theorien uber die Atiologie diskutiert wurden, sind in den letzten Jahren Befunde erhoben worden, die eine Virusinfektion moglich erscheinen lassen.