Biocompatibility and degradation of the open-pored magnesium scaffolds LAE442 and La2.

Porous magnesium implants are of particular interest for application as resorbable bone substitutes, due to their mechanical strength and a Young's modulus similar to bone. The objective of the present study was to compare the biocompatibility, bone and tissue ingrowth, and the degradation behaviour of scaffolds made from the magnesium alloys LAE442 (n= 40) and Mg-La2 (n= 40)in vivo. For this purpose, cylindrical magnesium scaffolds (diameter 4 mm, length 5 mm) with defined, interconnecting pores were produced by investment casting and coated with MgF2. The scaffolds were inserted into the cancellous part of the greater trochanter ossis femoris of rabbits. After implantation periods of 6, 12, 24 and 36 weeks, the bone-scaffold compounds were evaluated usingex vivo µCT80 images, histological examinations and energy dispersive x-ray spectroscopy analysis. The La2 scaffolds showed inhomogeneous and rapid degradation, with inferior osseointegration as compared to LAE442. For the early observation times, no bone and tissue could be observed in the pores of La2. Furthermore, the excessive amount of foreign body cells and fibrous capsule formation indicates insufficient biocompatibility of the La2 scaffolds. In contrast, the LAE442 scaffolds showed slow degradation and better osseointegration. Good vascularization, a moderate cellular response, bone and osteoid-like bone matrix at all implantation periods were observed in the pores of LAE442. In summary, porous LAE442 showed promise as a degradable scaffold for bone defect repair, based on its degradation behaviour and biocompatibility. However, further studies are needed to show it would have the necessary mechanical properties required over time for weight-bearing bone defects.

Assessment of a novel pinhole supplementary implant for sulcus fixation in pseudophakic cadaver eyes.

PurposeTo evaluate a novel small-aperture supplementary implant that applies the principle of pinholes for management of irregular astigmatism, in postmortem human eyes.MethodsPseudophakic human cadaver eyes were imaged by anterior segment optical coherence tomography (AS-OCT) to assess position of the in-the-bag intraocular lens (IOL). Eyes were prepared as per the Miyake-Apple technique. Two versions of the supplementary implant (open-loop and tripod designs) were then inserted into the sulcus of each eye. Evaluations under AS-OCT and from anterior and posterior views of the anterior segment were used to assess IOL fixation, centration, tilt, and interlenticular distance (ILD). This experimental study has been conducted in John A. Moran Eye Center, University of Utah.ResultsNine eyes were selected, with various sizes, primary IOL materials/designs, and Soemmering's ring formation. The open-loop model exhibited a mild degree of decentration and tilt in 2 eyes with zonular dehiscence. Mild decentration and tilt of the tripod were observed in 4 eyes; in 1 additional eye it was centered but mildly tilted. Three eyes with zonular dehiscence had one of the closed loops of the tripod located posteriorly to the ciliary processes. In all cases, an ILD was observed between the lenses (open loop: 0.65±0.13 mm; tripod: 0.41±0.12 mm).ConclusionsIt is important to take into account anatomical aspects related to ciliary sulcus fixation of supplementary IOLs. Both designs evaluated, exhibited appropriate centration and ILD. The open-loop design had less risk of tilt in association with haptics protruding posteriorly through areas of zonular weakness.

Assessment of a new hydrophilic acrylic supplementary IOL for sulcus fixation in pseudophakic cadaver eyes.

PurposeManagement of refractive errors after cataract surgery includes spectacles or contact lens, secondary laser vision correction, intraocular lens (IOL) exchange, or piggyback lens implantation. We evaluated for the first time a single-piece hydrophilic acrylic IOL designed for supplementary sulcus fixation in postmortem pseudophakic human eyes.MethodsPseudophakic human cadaver eyes were imaged by anterior segment optical coherence tomography (AS-OCT) to assess position of the primary IOL. Eyes were prepared as per the Miyake-Apple technique. The supplementary IOL (Medicontur A4 Addon IOL family) was then inserted into the ciliary sulcus. AS-OCT and photographs from anterior and posterior views were used to assess IOL centration, tilt, and interlenticular distance from the primary IOL.ResultsData were obtained from 12 eyes having primary IOLs of varying materials and designs in the bag and representing different sizes of eyes and severity of Soemmering's ring formation. The A4 Addon IOL was successfully inserted into the ciliary sulcus and was well centered in all cases. Four cases of tilt were observed on AS-OCT: three with mild tilt due to pre-existing zonular dehiscence, and one due to a localized area of Soemmering's ring formation. Interlenticular distance ranged from 0.34 to 1.24 mm and was not dependent on severity of Soemmering's ring or type of primary IOL.ConclusionsThe A4 Addon IOL was designed for sulcus fixation as a supplementary lens, with a large diameter, a square-shaped optic, four smooth loop haptics, and a convex-concave optical surface. It exhibited appropriate centration and interlenticular distance with different primary in-the-bag IOLs.

Identification of the high affinity Mn2+ binding site of bacteriophage lambda phosphoprotein phosphatase: effects of metal ligand mutations on electron paramagnetic resonance spectra and phosphatase activities.

Bacteriophage lambda phosphoprotein phosphatase (lambdaPP) has structural similarity to the mammalian Ser/Thr phosphoprotein phosphatases (PPPs) including the immunosuppressant drug target calcineurin. PPPs possess a conserved active site containing a dinuclear metal cluster, with metal ligands provided by a phosphoesterase motif plus two additional histidine residues at the C-terminus. Multiple sequence alignment of lambdaPP with 28 eubacterial and archeal phosphoesterases identified active site residues from the phosphoesterase motif and in many cases 2 additional C-terminal His metal ligands. Most highly similar to lambdaPP are E. coli PrpA and PrpB. Using the crystal structure of lambdaPP [Voegtli, W. C., et al. (2000) Biochemistry 39, 15365-15374] as a structural and active site model for PPPs and related bacterial phosphoesterases, we have studied mutant forms of lambdaPP reconstituted with Mn(2+) by electron paramagnetic resonance (EPR) spectroscopy, Mn(2+) binding analysis, and phosphatase kinetics. Analysis of Mn(2+)-bound active site mutant lambdaPP proteins shows that H22N, N75H, and H186N mutations decrease phosphatase activity but still allow mononuclear Mn(2+) and [(Mn(2+))(2)] binding. The high affinity Mn(2+) binding site is shown to consist of M2 site ligands H186 and Asn75, but not H22 from the M1 site which is ascribed as the lower affinity site.

Structure of the bacteriophage lambda Ser/Thr protein phosphatase with sulfate ion bound in two coordination modes.

The protein phosphatase encoded by bacteriophage lambda (lambda PP) belongs to a family of Ser/Thr phosphatases (Ser/Thr PPases) that includes the eukaryotic protein phosphatases 1 (PP1), 2A (PP2A), and 2B (calcineurin). These Ser/Thr PPases and the related purple acid phosphatases (PAPs) contain a conserved phosphoesterase sequence motif that binds a dinuclear metal center. The mechanisms of phosphoester hydrolysis by these enzymes are beginning to be unraveled. To utilize lambda PP more effectively as a model for probing the catalytic mechanism of the Ser/Thr PPases, we have determined its crystal structure to 2.15 A resolution. The overall fold resembles that of PP1 and calcineurin, including a conserved beta alpha beta alpha beta structure that comprises the phosphoesterase motif. Substrates and inhibitors probably bind in a narrow surface groove that houses the active site dinuclear Mn(II) center. The arrangement of metal ligands is similar to that in PP1, calcineurin, and PAP, and a bound sulfate ion is present in two novel coordination modes. In two of the three molecules in the crystallographic asymmetric unit, sulfate is coordinated to Mn2 in a monodentate, terminal fashion, and the two Mn(II) ions are bridged by a solvent molecule. Two additional solvent molecules are coordinated to Mn1. In the third molecule, the sulfate ion is triply coordinated to the metal center with one oxygen coordinated to both Mn(II) ions, one oxygen coordinated to Mn1, and one oxygen coordinated to Mn2. The sulfate in this coordination mode displaces the bridging ligand and one of the terminal solvent ligands. In both sulfate coordination modes, the sulfate ion is stabilized by hydrogen bonding interactions with conserved arginine residues, Arg 53 and Arg 162. The two different active site structures provide models for intermediates in phosphoester hydrolysis and suggest specific mechanistic roles for conserved residues.

Molecular and ultrastructural analysis of a nonchromosomal variegated mutant. Tomato mitochondrial mutants that cause abnormal leaf development.

Mutants were recovered in a population of cybrids formed following protoplast fusion between tomato (Lycopersicon esculentum Mill.) cv UC82 and Lycopersicon pennellii Corr. The cybrids were identified as individuals with recombinant cytoplasmic genomes but only tomato nuclear genomes. The mutants were identified based on two features, a variegated sectoring of light and dark green regions on their leaves, stems, and fruit, and reduced growth in the field. The mutants produced 50% of the shoot fresh weight and 20% of the fruit fresh weight of the parental type, UC82. The variegated sectoring was maternally inherited. The chloroplast genome in the mutants was indistinguishable from the chloroplast genome in UC82, when distribution of restriction endonuclease sites was used as an assay. The mitochondrial genome in the mutants, however, was recombinant, containing genes from UC82 and L. pennellii. Light microscopic analysis of the leaves of the mutants demonstrated an absence of the palisade layer in the variegated sectors. Electron microscopic analysis of these same regions demonstrated an absence of normal inner membranes in the mitochondria of these cells.

[Group respiratory biofeedback in complex neurorehabilitation]. / Das Gruppen-RFB in einer komplexen Neurorehabilitation.

Respiratory feedback is to be seen as an apparatus aided psychotherapy. Like other hypnoide psychotherapies it acts via the vegetative switch, enabling relaxation and dynamization, as well as intentional formula. Administration in a semi open group can be demonstrated within the frame work of neuro-rehabilitations, mainly pain-rehabilitation. The action is to be seen as well somatotropic as psychotropic, within a holistic approach.

[Comparative analysis of mental health treatment of various groups of competitive athletes]. / Vergleichsanalyse zur psychohygienischen Betreuung unterschiedlicher Gruppen von Spitzensportlern.

1) There is sense and necessity of psychohygiene in sports. This could be stated with 3 compared groups, namely: a national team, a team of handicapped, a team of juveniles. 2) We have used a complex program with integrated autogenic training (this however, not in an isolated way). Earlier experiences (of last author) over many years and hundreds of sportives were integrated in our evaluation. 3) Its to our knowledge the first time in world literature that effectiveness of psychohygiene within sports could be proved with statistical significance using world cup points within comparable groups. 4) Only possible can be possible, and psychohygiene will help to optimate this goal but not overrun it. This is main differentiation against doping. The human and the humanity is the main goal and not the so-called "necessities" of sport dictatorship. Its a good sign that several of our candidates told us that our psychohygienic program has reached over their period of sports activities into their "normal" lives.

[Personality markers in patients with Sudeck's disease. A psychoanalytic study]. / Persönlichkeitsmerkmale bei Patienten mit M. Sudeck. Eine tiefenpsychologische Untersuchung.

We examined 22 patients suffering from reflex sympathetic dystrophy with psychoanalytic interviews. In all 22 patients we found a common psychological structure corresponding to Balint's basic fault (Balint, 1970). For people with this structure the accident that preceded the reflex sympathetic dystrophy and the following pain, immobilisation and need to help are promoting the patient's regression in a specific way ending in the developing of reflex sympathetic dystrophy. The dispair of the patients about their reflex sympathetic dystrophy expresses unsolved fears of early childhood.