Zusammenfassung
Hintergrund
Der periprothetische Gelenkinfekt (PPI) gilt als große diagnostische und therapeutische Herausforderung. Er schmälert den Therapieerfolg, stellt eine enorme Belastung für ...die betroffenen Patienten dar und zieht häufig aufwendige operative Revisionen nach sich. Ein schrittweises aufwendiges diagnostisches Vorgehen ist hier bisher angezeigt, um zeit- und kostenintensive Irrläufe zu vermeiden. Die gegenwärtige (Gold-)Standarddiagnostik kommt jedoch insbesondere beim häufigen und klinisch relevanten chronischen „low-grade“-PPI an ihre Grenzen.
Einschätzung
Synoviale Biomarker zur sicheren Differenzierung einer aseptischen von der (chronischen) septischen sowie der implantatallergischen Beschwerdeursache und der Arthrofibrose werden momentan zur Überwindung der diagnostischen Lücke favorisiert. Die ambulant durchführbare Synovialpunktion ist dabei der operativen Synovial-(is-)Biopsie bei früherem Diagnosezeitpunkt, höherer Alltagspraktikabilität, geringerer Patientengefährdung und schließlich geringeren Kosten überlegen. Neben Parametern wie Interleukin-6 (IL-6), C-reaktives Protein (CRP) und Leukozytenesterase in der Gelenkflüssigkeit gelten innovative synoviale Biomarker aus der Gruppe der antimikrobiellen Peptide und proinflammatorischen Zytokine aufgrund sehr guter bis exzellenter diagnostischer Genauigkeit als besonders vielversprechend.
Schlussfolgerung
Welches (differenzial-)diagnostische Set verschiedener Biomarker bei der innovativen „one-stop-shop“-Strategie der synovialen Infektdiagnostik künftig zu favorisieren ist, müssen unabhängige Multicenter-Validierungsstudien zeigen.
A group of 92 medical students were immunized with a commercial recombinant hepatitis B vaccine (Engerix B). Antibody responses were determined and compared with those to plasma-derived Pasteur ...vaccine, obtained in 1986. Antibody concentrations were significantly higher in the group given recombinant vaccine, therefore this vaccine has superior immunogenicity and probably confers extended duration of protection.
Alterations in the expression of cell-surface receptors have been reported in HIV-infected cells for CD4, CD25 (IL-2 receptor), CD2, CD3 and CD8 and CD26. In the present study we provide evidence ...that CD21 is down-regulated in the human T-lymphoblastoid cell line MT2 after infection with HIV-1 and -2 isolates. The same effect was observed with ICAM-1 (CD54). CD21 expression was monitored by means of fluorescence intensity, its functional ability to bind to C3d and by quantitative measurement of CD21-antigen in supernatants and cell lysates using an immunoassay. In addition, the decrease of CD21 and ICAM-1-specific mRNA suggests a mechanism at a transcriptional level. Our data suggest that HIV might have a direct influence on the receptor expression.
We described previously cDNA clones representing a novel factor H-related 1.4 kilobase mRNA. This mRNA species codes for a doublet of serum proteins of M(r) 39,000 and 37,000 (p39/p37). The ...respective recombinant proteins of the three clones H-69, pFH1.4a, and pFH1.4b differ in the expression of the epitope recognized by the monoclonal antibody (mAb) 3D11. This probably reflects the difference of three amino acid residues of the deduced protein sequence. Here we report evidence for corresponding alterations in the native proteins p39/p37 in human sera. Employing mAb 3D11 and a polyclonal factor H-specific antiserum we detected three different patterns in western blot analyses of human sera which we provisionally termed FH1.4p+m+, FH1.4p+m-, and FH1.4p-m-. In the first pattern, p39/p37 were recognized by both antibodies, while in the second pattern the two proteins reacted only with the polyclonal antiserum. Both antibodies failed to detect p39/p37 in the third pattern. These phenotypes are found in the healthy population with frequencies of 0.556, 0.40, and 0.044, respectively. The frequencies of the alleles FH1.4*p+m+, FH1.4*p+m-, and FH1.4*p-m- were estimated to be 0.33, 0.46, and 0.21, respectively, assuming the gene distribution to be in Hardy-Weinberg equilibrium. Studies of 98 members from 27 families revealed an autosomal Mendelian inheritance. Southern blot data support our assumption of a polymorphism of the factor H-related proteins p39 and p37.
We studied the chemotactic effects of calcitonin gene-related peptide, vasoactive intestinal peptide, substance P (SP), and secretoneurin on PBMC and PBL using micropore filter assays. All four ...peptides induced migration of PBMC, whereas only calcitonin gene-related peptide, vasoactive intestinal peptide, and SP were chemotactic for PBL. Secretoneurin, known to induce monocyte chemotaxis, was unable to affect lymphocyte migration. Effects of SP on PBL were characterized by checkerboard analyses and represented true chemotaxis. Both T and B cells responded chemotactically to SP, the functional activity of SP residing in its C-terminal amino acid sequence. Involvement of neurokinin (NK) receptors was supported by inhibition of SP-induced migration of PBL with an NK1 receptor antagonist and induction of migration with Sar9, Met(O2)11SP and PyrGlu6, Pro9SP(6-11), two specific agonists for NK1 receptors, but not with beta-Ala8NK A(4-10), an agonist for NK2 receptors. PBL chemotaxis to SP was abolished by inhibition of tyrosin kinase but not by that of protein kinase C. Preincubation of PBL with pertussis or cholera toxin inhibited SP chemotaxis, indicating that in PBL, NK receptors for chemotaxis probably are coupled with G protein and involve a tyrosin kinase signaling pathway. We conclude that, together with calcitonin gene-related peptide and vasoactive intestinal peptide, SP is a lymphocyte chemoattractant, whereas secretoneurin, which is coreleased from sensory nerve endings, is not.
Stable transfection of Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA2) expressed as a fusion protein with the hormone-binding domain of the estrogen receptor was used to study expression of CD21 ...and other surface markers in different cell lines. Special emphasis was placed on cell lines with a normally low expression of CD21, especially on T cell lines. After induction of EBNA2, a substantial increase in CD21 mRNA was observed, as well as increased production of membrane CD21. This was found not only in cell lines of B cell origin, but also in the T cell line Jurkat. The amount of CD21 was quantitated by means of a fluorescence immunoassay, and found to correlate with the presence of EBNA2 protein. A decrease in EBNA2 abundance was associated with complete loss of cell-associated CD21. As we could also detect large amounts of soluble CD21 (sCD21) in the supernatant of the transfected cell lines, which exceeded the total amount contained in the respective cell lysates, this indicates considerable shedding of the newly synthesized receptor molecules induced by EBNA2, comparable to the situation described for CD23. It further provides an explanation of the recent findings of increased sCD21 levels in sera of patients with EBV-associated disease, and suggests a possible additional function of EBNA2 in vivo.
Zusammenfassung
Mit einer Prävalenz von bis zu 35 % ist die Instabilität des Hüftgelenks mit resultierender Luxation die praktisch wichtigste Komplikation nach Revisionsalloarthroplastik der Hüfte. ...Neben nicht beeinflussbaren Faktoren wie Alter und Geschlecht oder der Art der Revision spielen der Zugangsweg, die Auswahl des Implantates, die Gleitpaarung und die Implantatpositionierung eine entscheidende Rolle für die Stabilität des Revisionsimplantates. Zudem stehen dem Chirurgen mit dem Einsatz großer Köpfe und des Double-Mobility (DM)-Prinzips wirksame Maßnahmen zur Reduktion der Luxationsrate zur Verfügung. Nach einer entsprechenden Ursachenanalyse können diese technischen Mittel bedarfsgerecht und effektiv zur Luxationsprophylaxe eingesetzt werden.
Femoral revision of total hip arthroplasty is a technically demanding procedure. Therefore, accurate preoperative planning is essential for good clinical results. With many reconstruction methods ...available, the decision-making process can be complex. Well established classification systems can facilitate preoperative planning. At the time of revision surgery appropriate implants and instruments have to be available ensuring the possibility of managing operative complications. Primary goals of revision arthroplasty are restoration of the physiological joint biomechanics and primary stable fixation of the revision implant. In consideration of possible repeat revision surgery, cementless stem fixation should be preferred. Modular stems provide significant flexibility in restoring the center of rotation. Depending on the pre-existing femoral defect, osseous grafts can be necessary.The scope and classification systems of femoral osseous defects in revision arthroplasty will be discussed and different treatment options will be outlined, which guide the surgeon in selecting an appropriate method of reconstruction.
Zusammenfassung
30% aller Skelettmetastasen und 10% aller primären Knochentumoren sind in der Wirbelsäule lokalisiert, wobei Erstere v. a. in der Lenden- (LWS, 52%), Brust- (BWS, 36%) und ...Halswirbelsäule (HWS, 12%) zu finden sind. Symptome sind lokaler Schmerz oder im weiteren Verlauf pathologische Frakturen. Bei Letzteren kann es durch Kompression neuraler Strukturen zu sensiblen und motorischen Ausfällen bis hin zur Querschnittlähmung kommen. Falls die radiologische und ggf. laborchemische Diagnostik zur Diagnosesicherung nicht ausreichen, sollte eine Biopsie erfolgen. Eine präzise Diagnose sowie eine möglichst exakte Prognoseabschätzung sind Basis der Therapieentscheidung. Ziel der Behandlung ist, Stabilität und Schmerzfreiheit für den Patienten sowie eine ausreichende und dauerhafte Dekompression des Spinalkanals zu erreichen. Da es sich um eine palliative Situation handelt, stehen Schmerzerleichterung sowie der Erhalt der Mobilität im Vordergrund. Solitäre Metastasen sollten mit kurativem Ansatz therapiert werden.
