Peptidyl-Prolyl-cis/trans-Isomerases Mip and PpiB of Legionella pneumophila Contribute to Surface Translocation, Growth at Suboptimal Temperature, and Infection.

The gammaproteobacterium Legionella pneumophila is the causative agent of Legionnaires' disease, an atypical pneumonia that manifests itself with severe lung damage. L. pneumophila, a common inhabitant of freshwater environments, replicates in free-living amoebae and persists in biofilms in natural and man-made water systems. Its environmental versatility is reflected in its ability to survive and grow within a broad temperature range as well as its capability to colonize and infect a wide range of hosts, including protozoa and humans. Peptidyl-prolyl-cis/trans-isomerases (PPIases) are multifunctional proteins that are mainly involved in protein folding and secretion in bacteria. In L. pneumophila the surface-associated PPIase Mip was shown to facilitate the establishment of the intracellular infection cycle in its early stages. The cytoplasmic PpiB was shown to promote cold tolerance. Here, we set out to analyze the interrelationship of these two relevant PPIases in the context of environmental fitness and infection. We demonstrate that the PPIases Mip and PpiB are important for surfactant-dependent sliding motility and adaptation to suboptimal temperatures, features that contribute to the environmental fitness of L. pneumophila Furthermore, they contribute to infection of the natural host Acanthamoeba castellanii as well as human macrophages and human explanted lung tissue. These effects were additive in the case of sliding motility or synergistic in the case of temperature tolerance and infection, as assessed by the behavior of the double mutant. Accordingly, we propose that Mip and PpiB are virulence modulators of L. pneumophila with compensatory action and pleiotropic effects.

Influence of radiofrequency energy on polypropylene sutures in atrial tissue.

OBJECTIVE: Bipolar radiofrequency (RF) ablation is an established technique for the surgical treatment of atrial fibrillation. To create complete lesion sets, the bipolar device has to be partially inserted into the heart via a purse-string suture, which is subject to heat damage. We investigated the influence of RF ablation on the structure and function of polypropylene sutures. METHODS: Six polypropylene sutures (4/0 Prolene; Ethicon, Norderstedt, Germany) were sutured ex vivo into atrial auricles from excised pig hearts. The tissue was treated by bipolar, saline-irrigated RF ablation (Cardioblate; Medtronic, Duesseldorf, Germany), until increase of tissue impedance pointed out a transmural lesion. After fixation in formaldehyde, the sutures were carefully removed and examined for ultrastructural damage using scanning electron microscopy, comparing them to sutures with intentional damage by instrumental grips. Tensile strength was tested applying a force velocity of 200 mm/min. Here, parts from the ablated zones were compared with parts from nonablated zones of the same suture. RESULTS: We could not find ultrastructural damage in form of heat-induced changes in the helical polypropylene structure. Accordingly, the tensile strength of the ablated sutures (16.5 to 17.5 N) showed no difference to an untreated suture. In contrast, sutures damaged by instruments showed remarkable structural damage and could be torn without force. CONCLUSION: Bipolar, saline-irrigated RF ablation does not damage polypropylene sutures in spite of the heat applied to the tissue. Therefore, it is safe to create bipolar epi/endocardial lesions of the heart through polypropylene purse-string sutures.

[Fungus detection--a simple method. Screening with optical brighteners]. / Vereinfachte Pilzdetektion. Screeningmethode mit optischem Aufheller.

Histological detection of mycosis can be laboriously but can be easier by a simple fluorescenceoptical method. Optical brighteners (e.g. blankophor, calcofluor) make it possible to detect fungus cell walls without significant background fluorescence of resident tissue. Mycosis can be detected even in cytological slides after maceration by brighteners.

Acute and long-term results after transcoronary ablation of septal hypertrophy (TASH). Catheter interventional treatment for hypertrophic obstructive cardiomyopathy.

AIMS: To evaluate acute and long-term symptomatic, haemodynamic (at rest and during exercise) and electrophysiological results of transcoronary ablation of septal hypertrophy (TASH), a catheter interventional treatment for hypertrophic obstructive cardiomyopathy. METHODS AND RESULTS: Sixty-two transcoronary ablations of septal hypertrophy were performed by injection of 4.6+/-2.6 ml 96% ethanol into septal branches in 50 patients with hypertrophic obstructive cardiomyopathy and severe symptoms. Serial left and right heart catheterization, transoesophageal echocardiography and electrophysiological investigations were repeated 2 weeks and 7+/-1 months (n=37) after intervention. Transcoronary ablation of septal hypertrophy led to a reduction in septal thickness, sustained elimination of the outflow obstruction (51+/-41 vs 6+/-10 mmHg at rest, P<0.001; 134+/-48 vs 28+/-32 mmHg, P<0.001, post-extrasystolic), a decrease in left ventricular filling pressures at rest and during exercise and a pronounced clinical improvement. There was no evidence for the creation of an arrhythmogenic substrate as assessed by serial programmed electrical stimulation in 39 patients. However, permanent high-grade atrioventricular block occurred in 17% of the patients. There were two early, but no late deaths during a mean follow-up time of 10. 6+/-5.6 months. CONCLUSION: Transcoronary ablation of septal hypertrophy is a promising new treatment for hypertrophic obstructive cardiomyopathy in patients with severe symptoms. It should now be compared with alternative treatment strategies in prospective randomized studies.

[Neurohistological studies in allogeneic cruciate ligament transplants as intra-articular ligament replacement]. / Neurohistologische Untersuchungen bei allogenen Kreuzbandtransplantaten als intraartikulärer Bandersatz.

A multiplicity of surgical operations have been developed in an attempt to achieve satisfactory function after ACL repair. None of these procedures have been able to duplicate the fiber organization, attachment site anatomy, vascularity, or function of the ACL. 18 foxhounds received a deep frozen bone-ACL-bone allograft and a ligament augmentation device (LAD). Neurohistological changes were evaluated 3, 6, and 12 months following implantation. Modified silver impregnation method and gold chloride technique were used to examine the presence of nerve endings and axons. Two morphological distinct mechanoreceptors were identified, and then were categorized as follows: free nerve-endings golgi-like tendon receptors. Fine nerve endings were frequently ramified freely into ligament collagen bundles. Nerves and blood vessels were commonly associated. Like in normal ACL's both neuroreceptors were mostly located near the surface of the allografts and at both bony attachments. This study demonstrated the first histological evidence of viable mechanoreceptors and free nerve-endings in transplanted ACL-allografts, not previously reported in other ACL-substitutes using for ACL-reconstruction. Particularly important for post-op. rehabilitation, this technique may allow to reconstruct the proprioreceptive functions of normal anterior cruciate ligaments.

[Homologous cruciate ligament transplantation as intra-articular ligament replacement]. / Die homologe Kreuzbandtransplantation als intraartikulärer Bandersatz.

A multiplicity of surgical operations have been developed in an attempt to achieve satisfactory function after ACL repair. None of these procedures have been able to duplicate the fiber organization, attachment site anatomy, vascularity, or function of the ACL. 29 foxhounds received a deep frozen bone-ACL-bone allograft and a ligament augmentation device (LAD). Biomechanical, microvascular, and histological changes were evaluated 3, 6 and 12 months following implantation. The maximum load of the allograft/LADs were 34.3% (387.2 N) after 3 months, 49.3% (556.6 N) after 6 months and 61.1% (689.8 N) after a year. The maximal load was 69.1% (780 N). In general, after 6 months the allografts showed a normal collagen orientation. The allografts demonstrated no evidence of infection or immune reaction. No bone ingrowth into the LAD was observed. Polarized light microscopy and PAS-staining showed that the new bone/ligament substance interface had intact fiber orientation at the area of ligament insertion. Microvascular examination using Spalteholtz-technique revealed neovascularization and the importance of infrapatellar fat pad for the nourishment of the ACL-allografts.

Neurohistological findings after experimental anterior cruciate ligament allograft transplantation.

A multiplicity of surgical operations have been developed in an attempt to achieve satisfactory function after anterior cruciate ligament (ACL) repair. None of these procedures have been able to duplicate the fiber organization, anatomy of the attachment site, vascularity, or function of the ACL. Eighteen foxhounds received a deep-frozen bone-ACL-bone allograft and a ligament augmentation device. Neurohistological changes were evaluated 3, 6 and 12 months following implantation. The modified silver impregnation method and gold chloride technique were used to examine the presence of nerve endings and axons. Two morphologically distinct mechanoreceptors were identified and classified as free nerve endings and Golgi-like tendon receptors respectively. Fine nerve endings frequently ramified freely into ligament collagen bundles. Nerves and blood vessels were commonly associated. As in normal ACLs, both neuroreceptor types were mostly located near the surface of the allografts and at the two bony attachments. This study demonstrated the first histological evidence of viable mechanoreceptors and free nerve endings in transplanted ACL allografts, not previously reported in other ACL substitutes used for ACL reconstruction. Particularly importantly for postoperative rehabilitation, this technique may allow the reconstruction of the proprioceptive functions of normal ACLs.

Anterior cruciate ligament allograft transplantation for intraarticular ligamentous reconstruction.

A multiplicity of surgical operations have been developed in an attempt to achieve satisfactory function after anterior cruciate ligament (ACL) repair. None of these procedures have been able to reproduce the fiber organization anatomy of attachment site, vascularity, or function of the ACL. Twenty-nine foxhounds received a deep-frozen bone-ACL-bone allograft and a ligament augmentation device (LAD). Biomechanical, microvascular, and histological changes were evaluated 3, 6, and 12 months following implantation. The maximum loads of the allograft/LADs were 34.3% (387.2 N) after 3 months, 49.3% (556.6 N) after 6 months, and 61.1% (698.8 N) after a year. The maximum load was 69.1% (780 N). In general, after 6 months the allografts showed normal collagen orientation. The allografts demonstrated no evidence of infection or immune reaction. No bone ingrowth into the LAD was observed. Polarized light microscopy and periodic acid-schiff staining showed that the new bone-ligament substance interface had intact fiber orientation at the area of the ligament insertion. Microvascular examination using the Spalteholtz technique revealed revascularization and the importance of an infrapatellar fat pad for the nourishment of ACL allografts.

[Sternocostoclavicular hyperostosis]. / Hyperostosis sternocostoclavicularis.

On the basis of 4 patients from our own records we describe the rare syndrome of "Hyperostosis sternocostoclavicularis". The etiology of this disorder is still unclarified. In addition to a swelling that is generally only slightly tender to pressure, the most important symptom is usually a long-standing, intermittent, dull pain in the upper sternum, the claviculae and the adjacent uppermost ribs. Laboratory diagnosis usually shows an accelerated blood sedimentation rate, but other laboratory findings are unremarkable and rheumatological serology gives a negative result. The changes detected by radiography are described, as are the histological findings. Primary or secondary malignant osteomas are also to be taken into account in differential diagnosis. For therapy most authors recommend medicinal treatment with non-steroidal antiphlogistic agents.

[Orthopedic aspects of Crohn disease. Examples of extra-intestinal organ manifestations]. / Orthopädische Aspekte bei Morbus Crohn. Beispiele extraintestinaler Organmanifestationen.

Articular changes in Chron's disease represent extraintestinal organic manifestations which generally take the form of so-called enteropathic synovitis. Articular alterations - diagnosed as non-specific arthritis in the great majority of cases--may precede the intestinal disease. In very rare cases it can be shown that the joints display histological changes typical of Morbus Crohn. The etiology and pathophysiological mechanisms of the articular changes are not clear. Probable factors are: autoimmune disease, stimulation of the immunological system by exogenous antigens, induction of a self-sustaining inflammatory process, and demonstrable circulation of antigen-antibody complexes. Genetic factors seem to play a role (familial disposition). A pure "colonic Crohn" (= colitis granulomatosa) leads to a higher degree of articular alteration than a pure "small-intestine Crohn" (= ileitis terminalis). The joints preferentially affected are in the region of the lower extremities (knee and ankle joints). Concomitant Bekhterev's disease (spondylitiis ankylopoietica) is found in 7-10% of cases. Osteomyelitis represents a rare and serious complication: it can appear in the course of chronic Chron's disease (mainly with intestinal fistulas), especially in the region of the pelvic bones. Further aspects of interest from an orthopedic viewpoint are hypertrophic osteoarthropathy with periossal neoformation, granulomatous changes in the bone itself, and aseptic osteonecrosis.