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A healthy woman with acute onset of pulmonary oedema and severely depressed left ventricular function underwent endomyocardial biopsy under the clinical suspicion of fulminant myocarditis. While awaiting the results of biopsy, the situation deteriorated to Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) and extracorporeal membrane oxygenation was implanted. Finally, immunohistochemistry in biopsy specimen corresponded to fulminant lymphocytic myocarditis, although active myocarditis was excluded. Furthermore, gene expression profiling identified giant cell myocarditis although multinuclear cells were absent. This prompted the start of immunosuppression with cortisone and cyclosporine. The patient fully recovered.

Aims Human herpesvirus 6 (HHV-6) A and B are two betaherpesviruses that are associated with many conditions including roseola, drug-induced hypersensitivity syndrome, limbic encephalitis, and myocarditis. HHV-6 is integrated in the germline [chromosomically integrated HHV-6 (ciHHV-6)] in ∼0.8% of the human population. To date, the prevalence, species distribution, and treatment responses of ciHHV-6 are unknown for cardiac patients. Methods and results We determined the prevalence of HHV-6 and ciHHV-6 genotypes in 1656 endomyocardial biopsies of patients with persisting unexplained symptoms of heart failure. Infection of cardiac tissue was identified by nested PCR, electron microscopy, and immunohistochemistry. Virus load and mRNA levels were followed in ciHHV-6 patients treated with ganciclovir. HHV-6 was detected in 273 of 1656 cardiac tissues (16.5%; HHV-6B, 98.2%, HHV-6A, 1.8%) by PCR. Nineteen of the 1656 patients (1.1%) presented with persistently high HHV-6 copy numbers indicative of ciHHV-6. Sequencing confirmed ciHHV-6A in seven patients (36.8%) which was considerably higher than detected in non-ciHHV-6 patients. Inheritance was demonstrated in three selected families, confirming ciHHV-6 chromosomal integration by PCR and fluorescence in situ hybridization. HHV-6 reactivation and chromosomal integration were confirmed in peripheral blood mononuclear cells and heart tissue. Virus particles were identified in degenerating myocytes and interstitial cells. Antiviral treatment abolished viral mRNA and ameliorated cardiac symptoms. Conclusion Virus replication in cardiac tissue of ciHHV-6 heart failure patients suggests that ciHHV-6 reactivation causes persistence of unexplained heart failure symptoms. We demonstrated that antiviral treatment, effective in decreasing viral transcripts and clinical complaints of cardiomyopathies, is a new therapeutic option for ciHHV-6-associated diseases.

Carbon-bonded alumina manufactured by use of a novel binding system Carbores® P are among the most promising materials for future high temperature industry products. Their secure application is based on an accurate knowledge of their thermophysical properties. In this work, an experimental investigation will be presented for the determination of the coefficient of thermal expansion, thermal diffusivity, specific heat, and thermal conductivity within a temperature range up to 800 °C. Experiments are represented for materials containing various mass fractions of Carbores® P, produced through various processes. It is found that the coefficient of thermal expansion and thermal conductivity are decreased by an increasing mass fraction of Carbores® P, while the specific heat is not affected.

Graphite was dispersed in immiscible polyvinylidene "uoride/maleated polypropylene (PVDF/PPgMA) blends to improve electrical and thermal conductive properties by building a double-percolation structure. The morphology of PVDF/PPgMA blends was !rst investigated for several compositions by selective solvent extraction, scanning electron microscopy, and dynamic mechanical thermal analysis. Blends of PVDF and PPgMA were prepared in different relative fractions, and a PVDF/PPgMA ratio of 7/3 showed a well-co-continuous structure. From this blend, the morphology and properties of composites with different concentrations of graphite were investigated to prepare double-percolated structures. Graphite was observed to selectively localize in the PPgMA phase. The electrical and thermal conductive properties of graphite-containing blends were measured, showing enhanced conductivity for the double-percolation structures compared with single-polymer composites containing the same graphite loadings

Bioglass® particles of the compositions 45s5, 52s, and 55s were implanted in the distal femoral epiphysis of rabbits. Animals were sacrificed at 7, 28, and 84 days postoperatively and specimens investigated using electron microscopy and electron dispersive X-ray analysis. The intention was to correlate the finding of different types of multinuclear giant cells (MNGC) in the center of the implantation bed with earlier hypothesized accumulated particle eluates and changed particle compositions. The distribution of Si, Na, Ca, P, O, S, and Cl throughout the implantation bed was analyzed. Bioglass® particles degraded either in Si-rich remnants or in CaP-shells. MNGC of foreign body giant cell type in high numbers as well as of osteoclast-like type at later time intervals in small numbers were found on the surface of Si-rich as well as on Ca- and P-rich particle remnants. Osteoclast-like cells were detected on the particles after transformation in CaP-shells. It is concluded that the formation of different types of MNGC is determined by the composition of the substrate, that is, osteoclast-like cells develop exclusively on resorbable substrates. The absolute number of MNGC depended on the time after implantation and the solubility of the implant. Bone bonding, however, only occurred on Ca- and P-rich surfaces. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 370–379, 2004

A hollow fiber-in-fiber-based bioreactor system was tested for the applicability to host kidney epithelial cells as a model system for a bioartificial kidney. Hollow fibers were prepared from polyacrylonitrile (PAN), polysulfone-polyvinylpyrollidinone (PVP) blend (PSU) and poly(acrylonitrile-N-vinylpyrollidinone) copolymer P(AN-NVP). Hollow fibers with smaller and larger diameters were prepared so that the smaller fitted into the larger, with a distance of 50-100 microm in between. The following material combinations as outer and inner fiber were applied: PAN-PAN; PSU-PSU, PSU-P(AN-NVP). Madin-Darby kidney epithelial cells (MDCK) were seeded in the interfiber space and cultured for a period up to 14 days. Light, scanning, and transmission electron microscopy were used to follow the adhesion and growth of cells, and to characterize their morphology. As a result, we found that MDCK cells were able to grow in the interfiber space in mono- and multilayers without signs of systemic degeneration. Comparison of the different materials showed that PAN and P(AN-NVP) provided the best growth conditions, indicated by a tight attachment of cells on hollow fiber membrane, and subsequent proliferation and development of structural elements of normal epithelia, such as tight junctions and microvilli. In conclusion, the fiber-in-fiber design seems to be an interesting system for the construction of a bioartificial kidney.

In this study, rat bone marrow cells (RBM) were used to evaluate two biodegradable calcium phosphate bone cements and bioactive calcium phosphate ceramics. The substances investigated were: two novel calcium phosphate cements, Biocement F and Biocement H, tricalcium phosphate (TCP), surface-modified alpha-tricalcium phosphate [TCP (s)] and a rapid resorbable calcium phosphate ceramic consisting of CaKPO4 (sample code R5). RBM cells were cultured on disc-shaped test substrates for 14 days. The culture medium was changed daily and also examined for calcium, phosphate, and potassium concentrations. Specimens were evaluated using light microscopy, and morphometry of the cell-covered substrate surface, scanning electron microscopy, and energy dispersive X-ray analysis and morphometry of the cell-covered substrate surface. Areas of mineralization were identified by tetracyline labeling. Except for R 5, rat bone-marrow cells attached and grew on all substrate surfaces. Of the different calcium phosphate materials tested, TCP and TCP (s) facilitated osteoblast growth and extracellular matrix elaboration to the highest degree, followed by Biocements H and F. The inhibition of cell growth encountered with R 5 seems to be related to its high phosphate and potassium ion release. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res, 52, 498–508, 2000.

Aims This study was undertaken to clarify whether immunohistological detection of tenascin (TN), an extracellular matrix glycoprotein that is expressed during stromal remodelling, may allow a more precise diagnosis of collagenous colitis. Methods and results We studied multiple colorectal biopsies specimens from 15 patients with clinically suspected collagenous colitis for TN expression by using a monoclonal antibody. Biopsies from further 15 patients without symptoms and signs of collagenous colitis served as controls. In seven of the 15 cases with clinically suspected collagenous colitis a prominent and selective subepithelial tenascin expression was identified. The TN expression pattern closely correlated with the conventional detection of a subepithelial collagen band diagnostic of collagenous colitis. The immunohistological labelling for TN allowed a quicker and more precise measurement of the thickness of the diagnostic collagen deposits than conventional staining. By this approach one further case could be reclassified as collagenous colitis. Conclusions Our data show that immunohistological detection of TN allows a more correct and easy diagnosis of collagenous colitis.

Osteoblast activation after implantation of two kinds of surface-active material in bone was investigated chronologically using in situ hybridization with digoxygenin-labeled procollagen alpha 1(I) complementary RNA probe. The bioactive materials used were hydroxyapatite (HA) and apatite- and wollastonite-containing glass-ceramic (A-W GC). A hole was drilled bilaterally in the distal epiphysis of rabbit femurs with subsequent implantation of HA or A-W GC cylinders in a press-fit manner. Specimens were collected at 3, 7, 14, and 28 days after operation and decalcified. Then the undecalcified implant cores were pushed out of the hole without causing damage to the bony side of the interface. In situ hybridization documented no qualitative differences in the expression of procollagen alpha 1(I) RNA between HA and A-W GC. Few osteoblasts at the bone-material interface showed a specific signal at day 3, whereas many osteoblasts were positive around the materials at days 7 and 14, indicative of active new bone formation. The positive osteoblasts seemed to originate from preexisting trabeculae and lined the trabeculae, newly formed bone, and material surface. At day 28, many osteoblasts lining material-surrounding bone were negative, whereas those in remodeling canals were positive, suggesting that the bone was in the remodeling stage after bone formation. These findings were comparable to those with beta-tricalcium phosphate in a previous study, thus suggesting osteoconductive bone formation on HA and A-W GC.

Temporal and spatial patterns of osteoblast activation around beta-TCP particles implanted into bone were analyzed by in situ hybridization with digoxygenin-labeled procollagen alpha 1(I) RNA probes. beta-TCP particles (150-300 microns in diameter) were implanted into rat tibiae, and specimens were collected 3, 5, 7, 14, and 28 days after operation. Activated osteoblasts displayed intense procollagen alpha 1(I) RNA specific labeling. At day 3, osteoblasts lining pre-existing trabeculae in places showed a specific signal. Additionally, scattered activated cells compatible with preosteoblasts also were observed in the vicinity of the trabeculae among red blood cells that filled the space between beta-TCP particles. Osteoblast activation on the surface of beta-TCP rarely was observed. At days 5 and 7, osteoblast activation and bone formation advanced centripetally. At the forefront of bone formation positive cells were scattered in the blood cell clots, and some of the positive cells colonized forming new bone matrix. Formation of new bone did not always begin at the surface of beta-TCP. At day 14, most of the beta-TCP particles were tightly associated with newly formed bone, and the number of positive osteoblasts was reduced. At day 28, absorption of the newly formed bone and the beta-TCP by multinuclear cells was sporadically demonstrated. Such cells often were accompanied by active osteoblasts, suggesting early bone remodeling. In conclusion, in situ hybridization with procollagen alpha 1(I) was employed to demonstrate precisely the mode of recruitment of bone cell precursors. beta-TCP does not positively guide collagen I expressing bone cells along its surface. It has no apparent effects on bone regeneration.

To investigate the effects of bioactive materials on bone formation in vivo, a new experimental model using in situ hybridization has been developed. A hole was drilled bilaterally in the distal epiphysis of rabbit femurs with subsequent implantations of beta-tricalcium phosphate (beta-TCP) cylinders in a press-fit manner. Specimens were collected at 3, 7, 14, and 28 days after operation. Femurs with empty drilling holes, and normal distal femurs without operation were used as controls. All specimens were decalcified and hybridized with a procollagen alpha 1(I) complementary RNA probe labeled with digoxygenin. In normal-bone sections, procollagen alpha 1(I) RNA was clearly demonstrated in periosteal osteoblasts, in osteoblasts in the mineralizing zone adjacent to growth plates, and in osteoblasts lining remodeling canals. As for beta-TCP, labeled osteoblasts around the material were not found at day 3, whereas they were most intensively observed at day 7 and a little less at day 14, in accordance with new-bone formation around the material. Weaker signals were also detected in fibroblasts at day 7. At day 28, osteoblasts lining the surface of newly formed bone were mainly negative, whereas those adjacent to the resorption sites of the beta-TCP showed positive signals, demonstrating an active remodeling at the material surface. The temporal expression of procollagen alpha 1(I) RNA in the beta-TCP specimens was fundamentally the same as that in the empty-hole specimens, suggesting no remarkable acceleration or suppression of bone-forming activity of osteoblasts by beta-TCP, which is consistent with osteoconductive bone formation. This in situ hybridization method was suggested to be a powerful tool in analyzing the biological effects of bioactive materials.

This article reports on the reaction of bone to a new family of nanocrystalline hydroxyapatite biomaterials with crystal sizes similar to those of human bone. Pure nanoapatite cylinders and organoapatite cylinders containing a synthetic nanopeptide were analyzed 28 days after implantation into the spongy bone of Chinchilla rabbits. The experimental techniques used for analysis were light microscopy, scanning electron microscopy, and transmission electron microscopy. Both implant types were well incorporated, and interface events were found to be similar to those observed on human bone surfaces with regard to resorption by osteoclast-like cells and bone formation by osteoblasts. Different types of giant cells were observed resorbing the outermost surfaces of implants. There seemed to be both dissolution of the implant and particulate biodegradation leading to less dense implant regions near the interface, whereas the bulk of the implants remained denser. Transmission electron micrographs revealed that bone bonding occurred with and without an afibrillar intervening layer. Given the biologic reaction observed, these implant materials should be suitable for bone replacement and the organoapatite form could be useful for additional functions such as the release of drugs and optimized release of antibiotics, growth factors, or other substances. The organic component can also be used to control physical properties in a bony implantation bed. © 1995 John Wiley & Sons, Inc.

Type, size and distribution of extracellular matrix vesicles (MV), known mediators of primary calcification, were studied around bone-bonding and metal-oxide containing, nonbonding, glass-ceramic implants. This was performed in order to further understand the different effects of implants on bone healing. At 14 days after implantation in adult rat tibial bone the effects of different implants on MV were studied by transmission electron microscopy and computerized morphometry. A total number of 4607 MV in 245 electron micrographs were counted and grouped according to diameter, distance from the calcifying front, and classified as four types: "empty," "amorphous," "crystal," and "rupture." The sequence of types according to diameter and distance was recorded as follows around both implants tested: "rupture" MV were the closest to the front with the largest diameter, followed by "crystal," "amorphous," and "empty," MV with the largest distance from the front and the smallest diameter. Most vesicles were concentrated in a distance of less than 2.4 microns from the front and between diameters of 0.06 microns and 0.22 microns. The noncalcified extracellular matrix around bone-bonding implants contained more MV than the matrix around the nonbonding type (26.24 MV/10 microns2 and 18.76 MV/10 microns2). MV distribution according to types showed that around bonding implants there was a higher percentage of "crystal" and a lower percentage of "rupture" when compared to the nonbonding type. These results indicate that bonding implants affect osteoblastic function by increasing the vesicular number and retardation of intravesicular crystal formation. It might be suggested that bonding implants induce an increase in the process of primary calcification and a decreased rate of crystal formation resulting with the highest organization of the healing bone.

The extracts of four glass-ceramic bone implant materials were investigated for dissolved material, for effects on in vitro formation of hydroxyapatite, and for surface morphology of glass-ceramic particles in scanning electron microscopy. In vitro leaching released substances that affected in vitro formation of hydroxyapatite, i.e., initiation time and growth of crystals. Leaching also changed the surface morphology of the materials. The ability of the materials to bond to bone did not correlate with the inhibition of hydroxyapatite formation by the released substances. Surface morphology and other factors at present not yet known are probably involved in controlling the bonding to bone of these ceramics.

Von den silylierten Biphenylen reagieren das 3-(7) und die 4-bzw. 4,4′-Isomeren (8, 18) mit Tribromboran (9) glatt unter Ersatz der Trimethylsilygruppen zu den Aryldibromboranen 10, 11 und 19, wahrend bei dem 2-(12) bzw. 2,2′-Isomeren (4) losungsmittelabhangig uberwiegend Methylabspaltung unter Bildung von 14 bzw. 20 eintritt. Das Silafluoren 15 regiert mit 9 dagegen ausschlieslich zum Dibenzoborol 16. Die Umsetzung des 2,2′,3,3′-tetrakissilylierten Biphenyls 6 mit 9 fuhrt zuerst zu dem zweifach silylierten Silafluoren 21, dann jedoch unter zweifacher Methylabspaltung zu 22, da die zentrale Dimethylsilyleneinheit fur einen Austausch sterisch zu sehr abgeschirmt ist. 22 ist ein geeigneter Baustein zum Aufbau von Oligosilacyclen. Treatment of tribromoborane (9) with the 3-, 4-, and 4,4′ -silylated biphenyls 7, 8, and 18 leads to substitution of the silyl groups with formation of the aryldibromoboranes 10, 11, and 19, whereas depending on the solvent the 2-iomers 12 and 4 suffer methyl abstraction to predominatly yield 14 and 20. The reaction of the silafluorene 15 with 9 exclusively leads to the dibenzoborole 16. In the first step of the reaction of the 2,2′,3,3′-tetrakissilylated biphenyl 6 with 9 the bissilylated silafluorene 21 is formed, in the second a twofold abstraction of a methyl group yields 22, as the central dimethylsilylene group is too much shielded for an exchange reaction. 22 is a well suited building block for constructing cyclic oligosilanes.

Basing on histomorphological evaluations and morphometrical quantifications in a standardized model experiment, a comparison is made between the reactions of skeletal tissues to various glasses, glassceramics and enamels. On the surface of these so-called reactive biomaterials either a direct bonding to mineralized bone or also different amounts of osteoid or chondroid tissue formation can be observed, depending on the composition of the material. It is shown that (1) the solubility of the glasses cannot directly be related to the reactivity and the resulting bone bonding; (2) bone binds only to glasses with a controlled release of constituents and which exhibit a seam of extracellular matrix on their surface, in which normal primary mineralization can occur; (3) the release of constituents such as Al2O3, Ta2O5, ZrO2, or phosphates from the material can inhibit this normal mineralization and the transformation of chondroid tissue to bone; (4) if connective tissue instead of bone is present at the interface (either primarily or after bone remodelling), the dissolution (or corrosion) of the material may be no longer controllable, and the tissue reacts with a continuous inflammatory response to the corrosion products.