Pseudotumors in Small-Head Metal-on-Metal Total Hip Arthroplasties at a Minimum Follow-Up of 20 Years

BackgroundMetal-on-metal (MOM) surfaces in total hip arthroplasty (THA) have been used widely. Serum cobalt and chromium levels have been the standard investigation for follow-up examinations, but magnetic resonance imaging (MRI) with metal artifact reducing sequences has shown good results in detecting pseudotumors. The aim of this study is to survey a significant correlation among MRI findings, serum metal levels, and clinical scores in patients with small-head MOM implants and if serum cobalt and chromium levels are sufficient in detecting patients with pseudotumors in the long-term follow-up.MethodsAt a minimum follow-up of 20 years, 26 patients (29 THAs) of the original 98 patients (105 THAs) included in this study between November 1992 and May 1994 were available for follow-up examination. Clinical scores, serum metal ion levels, and MRIs were obtained.ResultsWe found mean serum cobalt levels of 1.87 μg/L (±3.44) and chromium levels of 2.23 μg/L (±2.96) and very good clinical and functional results (mean Harris Hip Score 88.6) in the long-term follow-up. Pseudotumors were detected in MRIs of 21 hips. There were no significant differences between patients with or without pseudotumors regarding serum metal levels and the correlation for clinical outcome scores, demographic data, and cup inclination. The cumulative rate of survival was still at 91.4% at 22.8 years.ConclusionThis study presents the first published data on small-head MOM hips, comparing metal ion levels, pseudotumors, clinical, and radiological results in a follow-up period of more than 20 years and reveals that serum metal levels are not significantly higher in patients with pseudotumors.Level of EvidenceTherapeutic Level III     

Risk Factors and Management of Leukopenia After Kidney Transplantation: A Single-Center Experience

BackgroundLeukopenia is a common complication after kidney transplantation. The etiology is multifactorial, with medication adverse effects and cytomegalovirus infection as main causes. Optimal strategies to prevent or treat posttransplant leukopenia remain unknown. We aimed to identify risk factors for leukopenia and to investigate the benefit of switching the immunosuppressive therapy to hydrocortisone as a continuous infusion.MethodsWe retrospectively evaluated all patients with leukopenia after kidney transplantation between 2007 and 2017 at our center relative to age- and sex-matched controls.ResultsLeukopenia was associated with the degree of rejection therapy before leukopenia, the immunosuppressive therapy before transplantation, and an induction therapy with rabbit antithymocyte globulin. Patients with leukopenia exhibited increased mortality, an increased incidence of bacterial and viral infections, and more acute rejections. Switching to hydrocortisone as a continuous infusion in patients with severe leukopenia decreased the duration of leukopenia and the incidence of subsequent viral infections, especially with cytomegalovirus.ConclusionLeukopenia is a risk factor for infectious complications and mortality, and it is associated with acute rejection. Switching immunosuppressive therapy to hydrocortisone as a continuous infusion is a safe approach to reduce the duration of leukopenia and the incidence of viral infections.     

Prognostic markers in pT3 bladder cancer: A study from the international bladder cancer tissue microarray project

PurposeWe evaluated the prognostic value of 10 putative tumor markers by immunohistochemistry in a large multi-institutional cohort of patients with locally advanced urothelial cancer of the bladder (UCB) with the aim to validate their clinical value and to harmonize protocols for their evaluation.Materials and MethodsPrimary tumor specimens from 576 patients with pathologic (p)T3 UCB were collected from 24 institutions in North America and Europe. Three replicate 0.6-mm core diameter samples were collected for the construction of a tissue microarray (TMA). Immunohistochemistry (IHC) for 10 previously described tumor markers was performed and scored at 3 laboratories independently according to a standardized protocol. Associations between marker positivity and freedom from recurrence (FFR) or overall survival (OS) were analyzed separately for each individual laboratory using Cox regression analysis.ResultsThe overall agreement of the IHC scoring among laboratories was poor. Correlation among the 3 laboratories varied across the 10 markers. There was generally a lack of association between the individual markers and FFR or OS. The number of altered cell cycle regulators (p53, Rb, and p21) was associated with increased risk of cancer recurrence (P < 0.032). There was no clear pattern in the relationship between the percentage of markers altered in an 8-marker panel and FFR or OS.ConclusionsThis large international TMA of locally advanced (pT3) UCB suggests that altered expression of p53, Rb, and p21 is associated with worse outcome. However this study also highlights limitations in the reproducibility of IHC even in the most expert hands.     

Radiologische Interventionen bei Schlaganfall

Notfall + Rettungsmedizin - In den letzten Jahren hat sich die mechanische Thrombektomie mit Stent-Retrievern als wichtiger Bestandteil der Behandlung des ischämischen Schlaganfalls etabliert....     

Stellenwert von Computertomographie und Magnetresonanztomographie bei der Diagnostik von Malignomen der Mundh?hle und des Oropharynx

Problem: There is a lack of clear criteria for the use of MR and CT in the diagnosis of head and neck cancer – some of it is even contradictory. The results of this study should lead to the establishment of more clear criteria. Patients: 165 patients suffering from head and neck tumors were subjected to a total of 463 CT and 197 MRI examinations. Results: The CT and MRI staging corresponded in 67% and 60% of the oropharynx tumors, respectively, with the clinical findings. In the case of oral cavity tumors, the clinical TNM stages were identical with CT and MRI results in 50% and 43% of cases, respectively. In the case of lymphatic node staging, the frequency of error was slightly higher using MRI, at 27%, compared with the CT rate of 22%. In the evaluation of cervical lymphatic nodes, CT proved to be more sensitive attaining 78% compared to the MRI rate of 69%. Conclusion: The results provide clear indications as to the MRI and CT examinations. Primary preoperative screening and post-therapeutic aftercare should be assessed using CT, as should lymphatic node diagnosis in the neck area. In the case of special problems such as, for example, the relevant bone and periostium infiltration, MR should be considered as a supplementary examination at a second stage.      

Influence of Fluorescent Labelling of Polystyrene Particles on Phagocytic Uptake,Surface Hydrophobicity,and Plasma Protein Adsorption

Purpose. To investigate the influence of fluorescent labelling of polystyrene particles on phagocytic uptake, surface hydrophobicity and protein adsorption. Methods. Phagocytic uptake was analysed using chemiluminescence. Hydrophobicity was quantified by adsorption measurements of a hydrophobic dye. Protein adsorption was evaluated by two-dimensional electrophoresis. Results. Commercially available fluorescently labelled particles showed marked differences when compared to unlabelled particles: phagocytic uptake and surface hydrophobicity of labelled particles were diminished. Also the plasma protein adsorption pattern was found to be different from the unlabelled particles: for example, the amount of fibrinogen adsorbed was strongly reduced on the labelled particles. On the other hand, some unknown proteins could be detected on the fluorescently marked particles. In contrast, plain polystyrene particles and labelled ones could be successfully synthesised by Paulke which did not show any considerable differences in phagocytic uptake, surface hydrophobicity and protein adsorption. Polysorbate 20 added as stabilizer to particle suspensions led to completely different behaviour of the particles: the particles showed altered protein adsorption patterns, dominated by immunoglobulins and especially by apolipoproteins. Furthermore, these particles were not phagocytized at all. Conclusions. Surface hydrophobicity and phagocytic uptake in vitro as well as the interactions with plasma proteins of commercially available polystyrene particles were strongly affected by fluorescent labelling. Particles synthesised by Paulke remained unchanged after labelling. The results show the importance of thorough surface characterization for using particles in test systems in vitro and in vivo.     

Flecked chorioretinopathy associated with Birt-Hogg-Dubé syndrome

Background: BirtHogg-Dubé's syndrome is a rare skin disease characterized by multiple trichofibromas of the skin and polyps of the intestine. Ophthalmologic manifestations associated with the syndrome have not been reported in detail. Case reports and methods: Two siblings suffering from Birt-Hogg-Dubé syndrome were examined clinically. Electrooculography and electroretinography were performed according to international standards. Color fundus photographs were taken as well as fluorescein angiograms. The two patients showed multiple perifollicular fibromas and trichodiscomas of the skin of the head. Funduscopy and fluorescein angiography revealed a flecked chorioretinopathy in one patient with progressive constriction of visual fields and severely reduced electroretinographic responses. Ophthalmoscopy in his sister showed peripheral pigmentary changes with only minor functional abnormalities. Conclusion: These findings suggest that Birt-Hogg-Dubé syndrome may be associated with a progressive flecked chorioretinopathy with constricted visual fields and that patients with the syndrome should undergo ophthalmological examination.     

Management of fibrous histiocytoma of the corneoscleral limbus: Report of a case and review of the literature

Background: Fibrous histiocytomas of the corneoscleral limbus are rare tumors. We present an additional case and review the treatment approaches in the literature. So far, only light and electron microscopic studies have been performed. We used immunohistochemical stains to further characterize the cellular composition. Methods: The excised lesion was routinely fixed and processed for light microscopy and immunohistochemical studies. For comparison, three dermal fibrous histiocytomas were also examined and processed similarly. Results: The corneolimbal tumor was mainly composed of fibroblasts and histiocytes with a large amount of interstitial collagen, arranged in a storiform pattern. Immunohistochemical stains were positive for histiocytes, fibroblasts, and a marker for mesenchymal cells. The staining pattern of the dermal lesions was similar. Conclusion: Fibrous histiocytomas of the corneolimbal region are morphologically benign, slowly growing and infiltrative tumors. Complete resection, especially of the deep margin, is suggested. The immunohistochemical staining pattern is similar to that of dermal fibrous histiocytomas, which behave in a benign manner.     

Renal response to amino acid infusion in rats: effect of dopamine receptor antagonists and benserazide

Previously, we have found that feeding is a dominant factor controlling urinary dopamine excretion (U_DA) in conscious rats (Mühlbauer and Osswald 1992). Since the renal response to feeding is also characterized by an increase in glomerular filtration rate (GFR), we wanted to investigate in a first step whether the feeding-induced elevations of GFR and U_DA could be causally related phenomena. Therefore, we studied the influence of dopamine synthesis and dopamine receptor blockade on the renal response to amino acid infusion (AA) in thiopental anesthetized rats. AA infusion (n = 7) increased GFR by 33±7% (P<0.001) and U_DA by 87±19% (P<0.001). In the presence of benserazide (BZD, n = 5), an inhibitor of dopamine synthesis, infused i.v. at a dose of 30 g/min/kg, U_DA was suppressed to values below detection limit and the AA-induced GFR increase was abolished. Continuous intravenous infusion of the DA₁ receptor antagonist SCH 23390 (SCH, n = 7) in a dose of 4.0 g/kg/min did not prevent the AA-induced increase in GFR (33±3%, P<0.001) and U_DA (97±12%, P< 0.001). In contrast, S-sulpiride (SUL), a specific DA₂ receptor antagonist, infused continuously i.v. in a dose of 5 g/kg/min, completely abolished the AA-induced GFR increase, while U_DA was increased 1.6-fold (P<0.01). Like BZD, both dopamine receptor antagonists did not affect renal sodium excretion substantially.Our results suggest, that endogenous dopamine could act as a mediator in the renal response to amino acid infusion in the rat, most likely by activation of DA₂ receptors. Correspondence to:B. Mühlbauer at the above address