Protein expression of MMP-13, uPA, and PAI-1 in pseudocapsular and interface tissue around implants of loose artificial hip joints and in osteoarthritis

Matrix metalloproteinase 13 (MMP-13), urokinase type plasminogen activator (uPA), and plasminogen activator inhibitor type-1 (PAI-1) have been reported to be involved in aseptic loosening of artificial hip joints. This study for the first time presents the protein levels of all of these factors in synovial-like interfaces between bone and prosthesis and in pseudocapsular tissues surrounding the artificial joint in patients with aseptic loosening (n=17) measured by ELISA. No differences were observed in the antigen expression of MMP-13, uPA, and PAI-1, comparing interface and pseudocapsular tissue. Also, no significant correlation between the protein expression of these factors and years from arthroplasty to revision or to type of fixation (cemented vs. cementless) was observed. As control, MMP-13, uPA, and PAI-1 antigen levels were also determined in the synovium of patients with osteoarthritis (n=10). Yet, the antigen levels of MMP-13, uPA, and PAI-1 in tissue specimens from patients with aseptic loosening of artificial hip joints were significantly higher compared to their expression in synovial capsular tissues obtained from patients with osteoarthritis. In conclusion, this study shows that elevated protein levels of uPA, PAI-1, and MMP-13 in periprosthetic pseudocapsular and interface tissues from patients after total hip replacement due to aseptic loosening seem not to be associated with the patient outcome.     

September 2002: 24-year-old female with a 6-month history of seizures

The September 2002 COM. A 24-year-old female presented with a history of 3 generalized seizures, the first of which had occurred 6 months before admission. Her neurological examination was normal, but upon admission her MRI showed a small cystic lesion in the left parieto-occipital region. The lesion was hyper-intense on T-2 weighted images and did not show contrast enhancment. At surgery, the tumor was found to be deep to the cortex and was a cyst with amber fluid surrounded by gliotic brain. Microscopically, the tumor was well-demarcated from the surrounding tissues, which showed reactive changes, including Rosenthal fibers. The tumor was composed of GFAP-positive glial cells, which were arranged in a pseudopapillary fashion around blood vessels. In between, the tumor cells were positive for neuronal markers. The diagnosis was papillary glioneuronal tumor (PGNT), a relatively recently described lesion that may be a variant of ganglioglioma. The current literature on PGNTs is reviewed.     

Changes in blood lactate and respiratory gas exchange measures in sports with discontinuous load profiles

This study compares two different sport events (orienteering = OTC; tennis = TEC) with discontinuous load profiles and different activity/recovery patterns by means of blood lactate (LA), heart rate (HR), and respiratory gas exchange measures (RGME) determined via a portable respiratory system. During the TEC, 20 tennis-ranked male subjects [age: 26.0 (3.7) years; height: 181.0 (5.7) cm; weight: 73.2 (6.8) kg; maximal oxygen consumption (V˙O₂max): 57.3 (5.1) ml·kg⁻¹·min⁻¹] played ten matches of 50 min. During the OTC, 11 male members of the Austrian National Team [age: 23.5 (3.9) years; height: 183.6 (6.8) cm; weight: 72.4 (3.9) kg; V˙O₂max: 67.9 (3.8) ml·kg⁻¹·min⁻¹] performed a simulated OTC (six sections; average length: 10.090 m). In both studies data from the maximal treadmill tests (TT) were used as reference values for the comparison of energy expenditure of OTC and TEC. During TEC, the average V˙O₂ was considerably lower [29.1 (5.6) ml^·kg^−1·min⁻¹] or 51.1 (10.9)% of VO₂max and 64.8.0 (13.3)% of V˙O₂ determined at the individual anaerobic threshold (IAT) on the TT. The short high-intensity periods (activity/recovery = 1/6) did not result in higher LA levels [average LA of games: 2.07 (0.9) mmol·l⁻¹]. The highest average V˙O₂ value for a whole game was 47.8 ml·kg^−1·min⁻¹ and may provide a reference for energy demands required to sustain high-intensity periods of tennis predominately via aerobic mechanism of energy delivery. During OTC, we found an average V˙O₂ of 56.4 (4.5) ml·kg⁻¹·min⁻¹ or 83.0 (3.8)% of V˙O₂max and 94.6 (5.2)% of V˙O₂ at IAT. In contrast to TEC, LA were relatively high [5.16 (1.5) mmol·l⁻¹) although the average V˙O₂ was significantly lower than V˙O₂ at IAT. Our data suggest that portable RGEM provides valuable information concerning the energy expenditure in sports that cannot be interpreted from LA or HR measures alone. Portable RGEM systems provide valuable assessment of under- or over-estimation of requirements of sports and assist in the optimization and interpretation of training in athletes. Electronic Publication     

Mechanism(s) promoting HIV-1 infection of primary unstimulated T lymphocytes in autologous B cell/T cell co-cultures

Resting CD4(+) T cells in the lymphoid tissue (LT) are essential producers of virions at the beginning of HIV infection in vivo. We previously developed a model that allowed in vitro infection of non-prestimulated T lymphocytes in the presence of autologous B lymphocytes and complement. In this study, we try to clarify the mechanism(s) responsible for virus transmission in unstimulated autologous B cell/T cell co-cultures. Ex vivo analyses of patient plasma samples revealed that HIV was opsonized. Flow cytometry showed that opsonized virus preferentially bound to complement receptor (CR)-2 on B lymphocytes in primary B cell/T cell co-cultures. As indicated by cytokine measurements and transwell experiments, soluble factors seemed to play a minor role in enabling infection. Rather, direct interaction between B and T lymphocytes and direct binding of opsonized virus to CR2 on B cells turned out to be essential for productive infection. Antibodies blocking cell-cell adhesion inhibited p24 antigen production. An anti-CR2 antibody blocking C3d-CR2 binding also significantly reduced viral replication. Since the infection of unstimulated T cells by opsonized primary HIV isolates in the presence of B cells was highly efficient independent of the tropism of the virus, this mechanism may be critical in the pathogenesis of HIV.     

Die Inkorporation von markiertem Sauerstoff aus Wasser in die ATP-, Kreatinphosphat- und Orthophosphat-Fraktion intakter Muskeln bei Ruhe,tetanischer Reizung und Erholung

Ohne ZusammenfassungMit 7 TextabbildungenDie vorliegenden Studien am Physiologischen Institut Freiburg i. Br. wurden durch einen Bundeszuschuß des Ministeriums für Atomkernenergie und Wasserwirtschaft (Bonn) ermöglicht. Die Untersuchungen in Zürich wurden aus Mitteln des Schweizer Nationalfonds getragen. Den genannten Institutionen gilt unser besonderer Dank. Vorläufige Mitteilungen über die Methode und die hier dargestellten Ergebnisse wurden bereits früher gegeben [siehe Fleckenstein, A. E. Gerlach, u. J. Janke gemeinsam mit P. Marmier: Naturwissenschaften 46, 365 (1959); Pflügers Arch. ges. Physiol. 270, 20 (1959); P. Marmier gemeinsam mit E. Gerlach, J. Janke u. A. Fleckenstein: Pflügers Arch. ges. Physiol. 270, 19 (1959); A. Fleckenstein: University of London Special University Lectures in Physiology 26–28. Oct. 1959: The turnover rates of high energy phosphate compounds during activity and rest as indicated by the oxygen exchange with H₂O¹⁸. Bericht von E. Gerlach sowie von J. Janke vor der Freiburger Med. Ges. vom 24. 11. 1959, vgl. Klin. Wschr. 38, 341–342 (1960)].     

Keratin immunohistochemistry in renal cell carcinoma subtypes and renal oncocytomas: a systematic analysis of 233 tumors

Keratin immunohistochemistry represents a widely applied differential diagnostic tool in surgical pathology. To investigate the value of keratin subtyping for the diagnosis among histological subtypes of renal cell carcinoma and oncocytomas, we performed a detailed immunohistochemical study, applying 22 different monoclonal keratin antibodies on a large series of 233 renal tumors [125 conventional, 22 chromophobe, and 20 papillary (12 type-1, 8 type-2 tumors) cancers and 66 oncocytomas] using a tissue microarray technique. Immunoreactivity for keratin 7, 8, 18, and 19 was present in all tumor entities, albeit in varying quantities. With antibodies directed against keratins 8 and 18, oncocytomas showed a distinct perinuclear and punctate dot-like pattern, which was not observed in renal cancer specimens. The only tumors showing immunoreactivity for keratin 20 were two type-2 papillary cancers. All other monospecific keratin antibodies yielded consistently negative results. Overall, in contrast to some recent publications, keratin subtyping generally appeared to be of additional value only for the differentiation of renal epithelial tumors. Hence, with respect to differential diagnostic value, Hales colloidal iron stain and vimentin immunostaining are still the most useful tools in renal tumor pathology.     

Phylogenetic analysis of the hexon loop 1 region of an adenovirus from psittacine birds supports the existence of a new psittacine adenovirus (PsAdV)

Summary. Adenovirus infections in psittacine birds have been well known. Most of these infections were caused by fowl adenoviruses (FAdV). In this study, liver samples showing typical histological signs of an adenovirus infection were collected from Poicephalus spp. with acute disease. A PCR amplifying the variable loop 1 region of the hexon gene was developed using primers located in two conserved pedestal regions. A PCR product of approximately 590 bp in size was amplified and sequenced. The sequence obtained grouped outside of the FAdV reference strains of the 12 serotypes as well as egg drop syndrome virus and turkey adenovirus 3 indicating that a new avian adenovirus was detected. In comparison to the FAdV reference strains, the percentage of identical nucleotides ranged between 60.3 and 67.0 and that of identical amino acids (aa) between 51.3 and 61.0. Furthermore, 37 unique aa exchanges were observed; out of these, 27 are located in the 4 hypervariable regions of loop 1, which encode the serotype-specific epitops. The g/c content, the isoelectric point and the charge of the amplified fragment, however, are in the range as those of group I avian adenoviruses. It was proposed, therefore, to designate this new adenovirus as psittacine adenovirus (PsAdV).