Systemic inhibition or global deletion of CaMKK2 protects against post-traumatic osteoarthritis.

OBJECTIVE: To investigate the role of Ca2+/calmodulin-dependent protein kinase 2 (CaMKK2) in post-traumatic osteoarthritis (PTOA). METHODS: Destabilization of the medial meniscus (DMM) or sham surgeries were performed on 10-week-old male wild-type (WT) and Camkk2-/- mice. Half of the DMM-WT mice and all other cohorts (n = 6/group) received tri-weekly intraperitoneal (i.p.) injections of saline whereas the remaining DMM-WT mice (n = 6/group) received i.p. injections of the CaMKK2 inhibitor STO-609 (0.033 mg/kg body weight) thrice a week. Study was terminated at 8- or 12-weeks post-surgery, and knee joints processed for microcomputed tomography imaging followed by histology and immunohistochemistry. Primary articular chondrocytes were isolated from knee joints of 4-6-day-old WT and Camkk2-/- mice, and treated with 10 ng/ml interleukin-1ß (IL)-1ß for 24 or 48 h to investigate gene and protein expression. RESULTS: CaMKK2 levels and activity became elevated in articular chondrocytes following IL-1ß treatment or DMM surgery. Inhibition or absence of CaMKK2 protected against DMM-associated destruction of the cartilage, subchondral bone alterations and synovial inflammation. When challenged with IL-1ß, chondrocytes lacking CaMKK2 displayed attenuated inflammation, cartilage catabolism, and resistance to suppression of matrix synthesis. IL-1ß-treated CaMKK2-null chondrocytes displayed decreased IL-6 production, activation of signal transducer and activator of transcription 3 (Stat3) and matrix metalloproteinase 13 (MMP13), indicating a potential mechanism for the regulation of inflammatory responses in chondrocytes by CaMKK2. CONCLUSIONS: Our findings reveal a novel function for CaMKK2 in chondrocytes and highlight the potential for its inhibition as an innovative therapeutic strategy in the prevention of PTOA.

[Environmentally induced (extrinsic) skin aging]. / Umweltinduzierte (extrinsische) Hautalterung.

Chronic exposure to ultraviolet light, particularly as a component of natural sunlight, is a major cause of environmentally induced aging of the skin. In addition, other environmental factors for premature skin aging include longer wavelength radiation in the visible light region and in particular in the shortwave infrared radiation region. Furthermore, particulate and gaseous components of air pollution significantly contribute to the aging process.

[New spirometric reference values for children and adolescents in Germany considering height and non-linear age effects: the LUNOKID-study]. / Neue spirometrische Referenzwerte für Kinder und Jugendliche in Deutschland unter Berücksichtigung der Größe und nichtlinearer Alterseffekte: Die LUNOKID-Studie.

BACKGROUND: Comparing children's lung function with reference values is important for diagnosing respiratory diseases. The values by Zapletal et al., commonly used nowadays, are not appropriate for the current stage of children's development. We have now developed new reference values and a lower limit of normal (LLN) for children in Germany, divided into small-range age and height categories. MATERIAL AND METHODS: We examined 4- to 18-year-old children in 3 German communities under field conditions. 1943 children were healthy and had a visually acceptable lung function which also fulfilled international quality criteria. We used the regression model LMS, which was introduced by Stanojevic and Quanjer in this context. RESULTS: There were significant differences between the measured lung function and the predicted values according to Zapletal et al. The lung function did not only depend on the child's height, but also in a non-linear way on the age. The variation coefficient did not depend on age. CONCLUSIONS: To avoid diagnostic errors, the currently often used reference values according to Zapletal et al. should no longer be used. The non-linear dependence on age corresponds to the recently published results by Stanojevic and Quanjer.

Plasma of pregnant and preeclamptic women activates monocytes in vitro.

OBJECTIVE: The objective of the study was to test the hypothesis that factors circulating in the plasma of pregnant women and women with preeclampsia activate monocytes. STUDY DESIGN: Blood samples were taken from patients with early-onset severe preeclampsia (n = 9), healthy pregnant women (n = 9), and healthy nonpregnant women (n = 9). A monocytic cell line was incubated with the plasma for 4, 16, and 24 hours. After the incubation, reactive oxygen species (ROS) production and intercellular adhesion molecule (ICAM)-1 expression (protein and messenger ribonucleic acid) were measured. RESULTS: Plasma of both pregnant women and women with preeclampsia, as compared with plasma from nonpregnant women, increased the mean channel brightness (MCB) of ROS after 4 hours of incubation, whereas only plasma of pregnant women increased the percentage of cells producing ROS (after 4 and 24 hours of incubation). Plasma of pregnant women and women with preeclampsia up-regulated the percentage of ICAM-1-expressing cells after 4 hours and down-regulated the percentage of ICAM-1-expressing cells and MCB after 24 hours. CONCLUSION: Plasma of both pregnant women and women with preeclampsia activated monocytes in vitro.

Novel histamine H(3)-receptor antagonists with carbonyl-substituted 4-(3-(phenoxy)propyl)-1H-imidazole structures like ciproxifan and related compounds.

Novel histamine H(3)-receptor antagonists possessing a 4-(3-(phenoxy)propyl)-1H-imidazole structure generally substituted in the para-position of the phenyl ring have been synthesized according to Mitsunobu or S(N)Ar reactions. With in vitro and in vivo screening for H(3)-receptor antagonist potency, the carbonyl-substituted derivatives proved to be highly active compounds. A number of compounds showed in vitro affinities in the subnanomolar concentration range, and the 4-hexanoyl (10) and 4-acetyl-3-methyl (29) substituted derivatives showed in vivo antagonist potencies of about 0.1 mg/kg after po administration. Many proxifans were also tested for their affinities at other histamine receptor subtypes thereby demonstrating their pronounced H(3)-receptor subtype selectivity. Since the cyclopropyl ketone derivative 14 (ciproxifan) had high affinity in vitro as well as high potency in vivo, it was selected for further studies in monkeys. It showed good oral absorption and long-lasting, dose-dependent plasma levels making it a promising compound for drug development.

Novel partial agonists for the histamine H(3) receptor with high in vitro and in vivo activity.

Novel branched N-alkylcarbamates and aliphatic ethers derived from 3-(1H-imidazol-4-yl)propanol were prepared. The compounds were investigated on two functional histamine H(3)-receptor assays. Some compounds displayed partial agonist activity on synaptosomes of rat brain cortex but behaved as pure competitive antagonists on the guinea pig ileum. Under in vivo conditions after po application to mice, some of the compounds showed partial or full agonist activity. Highest in vivo potency was found for the 3,3-dimethylbutyl ether 10 (ED(50) = 0.29 mg/kg, full intrinsic activity). These novel agonists are structurally diverse from classical aminergic histamine H(3)-receptor agonists (e.g., (R)-alpha-methylhistamine, imetit) as they lack a basic moiety in the side chain, which is supposed to be important for the activation of the receptor protein. The selectivity for the histamine H(3) receptor was proven by determination of H(1)- and H(2)-receptor activity on functional assays of the guinea pig.

Development of FUB 181, a selective histamine H3-receptor antagonist of high oral in vivo potency with 4-(omega-(arylalkyloxy)alkyl)-1H-imidazole structure.

A series of 4-(omega-(arylalkyloxy)alkyl)-1H-imidazoles and related sulphur-containing compounds have been prepared and evaluated for their histamine H3-autoreceptor antagonist in vitro potency in an assay on synaptosomes of rat cerebral cortex. In addition, the in vivo potency has been determined from the changes in N tau-methylhistamine levels in brain after p.o. administration to mice. Compounds with different alkyl chains and various aryl moities have been synthesized and tested to explore structure-activity relationships. Within this series of novel antagonists, (1H-imid-azol-4-yl)methyl and 2-(1H-imidazol-4-yl)ethyl ether derivatives showed low to moderate H3-receptor antagonist potency, whereas the corresponding allyl and propyl derivatives were compounds with high antagonist in vitro potency. Corresponding thioether or sulphoxide derivatives also showed antagonists activity. Additionally, some ether derivatives possessed high in vivo potency as well. The most active ether derivatives under in vivo conditions were 4-(3-(3-(4-fluorophenyl)propyloxy)propyl)-1H-imidazole (11b) and the corresponding chloro compound 11c (FUB 181) with ED50 values of 0.76 and 0.80 mg/kg, respectively. On the other hand, all compounds tested showed weak activity at histamine H1 or H2 receptors. Furthermore, the most promising ether FUB 181 exhibited low activity at adrenergic alpha 1, beta 1/2, serotonergic 5-HT2A, 5-HT3, and muscarinic M3 receptors. Time-course investigations of FUB 181 in mice showed a rapid mode of action with the highest value 3 h after p.o. application. Thus, FUB 181 appears to block histamine H3 receptors potently and selectively.

Search for novel leads for histamine H3-receptor antagonists: oxygen-containing derivatives.

This study was performed in order to develop new leads for antagonists of the histamine H3-receptor subtype. omega-(1 H-Imidazol-4-yl)alkyl derivatives with ester, ketone or alcohol functionality in the side chain were synthesized and tested concerning their H3-receptor antagonist activity on synaptosomes of rat cerebral cortex. The novel compounds, which possess no nitrogen-containing polar group in the side chain of the imidazole moiety, presented moderate to high antagonist potency in vitro. In this series 3-(1 H-imidazol-4-yl)propyl-3-cyclopentylpropanoate (4) was the most potent compound in vitro with -log Ki = 8.5. Unfortunately, no central antagonist H3-receptor activity was detectable for ester derivatives in the in vitro H3-receptor assay based upon measurement of brain N tau-methylhistamine levels after p.o. administration to mice. Some of these novel antagonists are useful tools for investigations on ligand-receptor interaction because of their distinct receptor activities. On the other hand, the ketone derivative 1-(1 H-imidazol-4-yl)-7-phenyl-4-heptanone (9) in vitro presented an ED50-value of 3.5 +/- 1.5 mg/kg p.o. thus proving to be a new lead for further drug investigations. The most potent compounds in vitro and in vivo also showed high H3-receptor selectivity when tested at other histamine receptor subtypes.

Copy-milled aluminous core ceramic crowns: a clinical report.

Copy-milled, all-ceramic crowns were produced in a clinical setting. The advantages of this new technique are shortening of processing time and reduction in defects during processing through the use of an industrially prefabricated material.

Dehydroepiandrosterone and diseases of aging.

Dehydroepiandrosterone (DHEA; prasterone) is a major adrenal hormone with no well accepted function. In both animals and humans, low DHEA levels occur with the development of a number of the problems of aging: immunosenesence, increased mortality, increased incidence of several cancers, loss of sleep, decreased feelings of well-being, osteoporosis and atherosclerosis. DHEA replacement in aged mice significantly normalised immunosenescence, suggesting that this hormone plays a key role in aging and immune regulation in mice. Similarly, osteoclasts and lymphoid cells were stimulated by DHEA replacement, an effect that may delay osteoporosis. Recent studies do not support the original suggestion that low serum DHEA levels are associated with Alzheimer's disease and other forms of cognitive dysfunction in the elderly. As DHEA modulates energy metabolism, low levels should affect lipogenesis and gluconeogenesis, increasing the risk of diabetes mellitus and heart disease. Most of the effects of DHEA replacement have been extrapolated from epidemiological or animal model studies, and need to be tested in human trials. Studies that have been conducted in humans show essentially no toxicity of DHEA treatment at dosages that restore serum levels, with evidence of normalisation in some aging physiological systems. Thus, DHEA deficiency may expedite the development of some diseases that are common in the elderly.

Colorimetric analysis as a means of quality control for dental ceramic materials.

In this in-vitro study colorimetric analysis using the CIELAB-system was applied to two all-ceramic materials in shades A1 and A2. The material for the 96 specimens was taken from three production batches and examined spectrophotometrically after firing. For both materials the firing-process led to only small colour differences (average DE-value < 2.2). Between the three batches of each material, significantly higher, visually perceivable colour differences were detected. The results revealed that the Castor system is capable of producing high-precision colour measurements. The use of spectrophotometric devices is recommended as a means of quality control in order to decrease colour tolerances between different batches of the same material.

Novel histamine H3-receptor antagonists with benzyl ether structure or related moieties: synthesis and structure-activity relationships.

In search of new histamine H3-receptor ligands sixteen ether derivatives of 3-(1H-imidazol-4-yl)propanol with benzylic partial structure or related moieties were prepared and investigated as H3-receptor antagonists. The new compounds belong to a general construction pattern developed by other histamine H3-receptor antagonists. Structural modifications were introduced in an attempt to optimize in vitro as well as in vivo activity. Structure-activity relationships of the new histamine H3-receptor antagonists are discussed. All ether derivatives showed in vitro activities in the nanomolar concentration range, but only compounds with bulky lipophilic residues were also active under in vivo conditions. The most active compound within this series was 3-(1H-imidazol-4-yl)propyl 1-naphthylmethyl ether (4n) presenting an ED50 of 3.2 +/- 1.9 mg/kg regarding enhancement of endogenous histamine in brain after p.o. administration to mice. Furthermore, comparison of the H3-receptor activities measured on synaptosomes of rat cerebral cortex and on guinea pig ileum gave a good correlation indicating homogeneity of central and peripheral H3-receptor test models. The most interesting compounds were also evaluated in functional in vitro assays with regard to their activities at histamine H1-, H2-, and muscarinic M3-receptors. The tested compounds showed very weak activities at these receptor subtypes demonstrating their H3-receptor selectivity.

[125I]iodoproxyfan and related compounds: a reversible radioligand and novel classes of antagonists with high affinity and selectivity for the histamine H3 receptor.

The synthesis and biological evaluation of new histamine H3 receptor antagonists with an iodinated aryl partial structure are described as part of an extensive research program to find model compounds for the development of a new radioligand with high H3 receptor affinity and specific activity. All compounds were tested for their H3 receptor antagonist activity in a [3H]-histamine-release assay with synaptosomes from rat cerebral cortex. The new leads with potent H3 receptor antagonist activity belong to a series of derivatives of 3-(1H-imidazol-4-yl)propanol with carbamate (4-7), ester (8-16), and ether (17-22) as functional groups. Structure-activity relationships are discussed. The most active compound in the functional test (-log Ki = 8.3) and in binding studies with [3H]-(R)-alpha-methylhistamine on rat cerebral cortex (-log Ki = 9.0) in vitro was 3-(1H-imidazol-4-yl)propyl (4-iodophenyl)methyl ether (iodoproxyfan, 19) exhibiting no central H3 receptor antagonist activity in vivo. The potency of iodoproxyfan is more than 300 times lower at H1, H2, alpha1, alpha2, beta1, 5-HT2A, 5-HT3, and M3 receptors than at histamine H3 receptors. Because of the high potency and selectivity of 19, this compound has also been prepared in the [125I]-iodinated form by a nucleophilic halogen exchange reaction using the corresponding bromo derivative 22 as a precursor. The newly prepared [125I]iodoproxyfan (23) possesses advantageous pharmacological properties and fulfills all criteria of a useful radioligand.

Marginal accuracy and fracture strength of conventional and copy-milled all-ceramic crowns.

In this comparative in vitro study, the marginal accuracy and fracture strength of conventional and copy-milled In-Ceram crowns were examined. Anterior crowns with medians of 32.5 microns for the conventional technique and 38 microns for the copy-milled units had significantly smaller gaps than premolar crowns that had a median marginal gap of 45 microns for both techniques. There was a significant difference in fracture strength only for anterior crowns. The study indicates that copy-milled In-Ceram crown have clinically acceptable margins and fracture strength and reduce laboratory fabrication time.

[The quality appraisal of copy-milled complete-ceramic crown structures (Celay/In-Ceram)]. / Qualitätsbeurteilung von kopiergefrästen vollkeramischen Kronengerüsten (Celay/In-Ceram).

In the present in vitro-study, the fitting accuracy on In-Ceram crown structures, produced by copy milling under the Celay system, is examined. A total of 32 specimen was produced for four different stump forms (idealized incisor and premolar, each with a shoulder preparation or a 120 degree chamfer preparation) with indirect techniques. The data for the marginal gap ranged between 6 and 274 microns. The shoulder preparation lead to significantly better fitting qualities than the 120 degree chamfer preparation. Median gaps were found at 44 microns (premolar) and 32 microns (incisor). Examinations under the scanning electron microscope showed a homogeneous structure of the sinter with a small variation of grain size and a compact particle packing. As far as the clinical application of In-Ceram crown structures, produced by copy milling, is concerned, a shoulder preparation with a rounded inner edge is recommended.

[Biomechanically optimized construction of occlusal splints and subjective evaluation by probands]. / Biomechanisch optimierte Aufbissbehelfe-Herstellung und subjektive Bewertung durch Probanden.

In a double blind study twelve class I probands received occlusal splints with six different customized anterior guidances. The subjective feelings were rated using a psychologic scale. It was shown, that splints with a large "a" were better rated than splints with a small "a". "a" is the radius of the maximal curvature of the sagittal anterior tooth curvature. The transition between positive and negative ratings was very sharp and localized at the individual "a". These results suggest that occlusal splints can be optimized by including customized anterior guidances. A detailed technical description of the manufacturing of these splints is given.

[Biophysical properties of the articular disc tissue and their functional evaluation]. / Biophysikalische Gewebseigenschaften des Discus articularis und ihre funktionelle Deutung.

Acoustic methods (measuring the speed of sound) and separate measurements of the density of 10 fresh, unfixed discs at the anterior, central and posterior band were used to determine the module of elasticity. The values of 2634 to 3217 N/mm2 demonstrate the high resistance of the articular disc to elastic deformation. The consequences relating to the function, dysfunction and treatment of internal derangements are discussed.

[Augmentation of severely atrophied jaws with hydroxyapatite from a prosthodontics standpoint]. / Zur Augmentation des stark atrophierten Kiefers mit Hydroxylapatit aus prothetischer Sicht.

After 4 years of routine application of hydroxylapatite ridge augmentation 109 patients underwent a posttreatment examination. The quality of the alveolar ridge and the denture as well as the functional status of the craniomandibular system were evaluated in detail. For the maxilla good results were obtained in 80-90%, for the mandible in 70-80%. Further improvements seem more probable by the avoidance of prosthodontic faults and the elimination of functional disturbances than by additional surgical procedures such as vestibuloplasty.