[Lutetium-177-PSMA radioligand therapy : Consensus within the framework of GKV-funded care between the university hospitals in Aachen, Bonn, Düsseldorf, Essen, and Cologne and the MDK Nordrhein]. / Lutetium-177-PSMA-Radioligandentherapie : Konsensus im Rahmen der GKV-finanzierten Versorgung zwischen den Hochschulkliniken in Aachen, Bonn, Düsseldorf, Essen und Köln und dem MDK Nordrhein.

In the last 3 years, Lutetium-177 prostate-specific membrane antigen radioligand therapy (Lu-177-PSMA-RLT) has received increasing attention in nuclear medicine as a new form of treatment for castration-resistant metastatic prostate cancer. This therapy combines the radionuclide Lutetium-177, which has been therapeutically used in nuclear medicine for many years, with a molecular target of the transmembrane prostate-specific membrane antigen expressed by prostate cancer cells. Since there are no prospective randomized studies on Lu-177-PSMA-RLT and the question of reimbursement has repeatedly been the subject of review by the MDK Nordrhein (Medischenische Dienst der Krankenversicherung), there was a desire because of the increasing number of patients being treated to clarify under which circumstances Lu-177-PSMA-RLT can be reimbursed by German statutory health insurance. The goals of this article are to help treating physicians understand how this new therapy option works, to integrate it in the overall therapy concept for castration-resistant metastatic prostate cancer, and, above all, to use Lu-177-PSMA-RLT-based on the current data-at the right place in the therapy sequence of castration-resistant metastatic prostate cancer.

Increased dopaminergic neurotransmission in therapy-naïve asymptomatic HIV patients is not associated with adaptive changes at the dopaminergic synapses.

Central dopaminergic (DA) systems are affected during human immunodeficiency virus (HIV) infection. So far, it is believed that they degenerate with progression of HIV disease because deterioration of DA systems is evident in advanced stages of infection. In this manuscript we found that (a) DA levels are increased and DA turnover is decreased in CSF of therapy-naïve HIV patients in asymptomatic infection, (b) DA increase does not modulate the availability of DA transporters and D2-receptors, (c) DA correlates inversely with CD4+ numbers in blood. These findings show activation of central DA systems without development of adaptive responses at DA synapses in asymptomatic HIV infection. It is probable that DA deterioration in advanced stages of HIV infection may derive from increased DA availability in early infection, resulting in DA neurotoxicity. Our findings provide a clue to the synergism between DA medication or drugs of abuse and HIV infection to exacerbate and accelerate HIV neuropsychiatric disease, a central issue in the neurobiology of HIV.

A German Chlamydia trachomatis screening program employing semi-automated real-time PCR: results and perspectives.

BACKGROUND: Genital Chlamydia trachomatis infection is a worldwide public health burden. A screening program for C. trachomatis was therefore initiated by the public health insurers in Germany ("Gemeinsamer Bundesausschuss", GBA) in April 2008. OBJECTIVES: To estimate C. trachomatis prevalence from screening 115,766 asymptomatic females and 20,033 female patients with unspecific abdominal pain. STUDY DESIGN: Urine samples (pooled by five for the asymptomatic screening subjects) and cervical swabs were analyzed using semi-automated real-time PCR. Infection prevalence was determined separately in four categories of women, defined by health status (asymptomatic screening vs. non-screening with unspecified symptoms) and test material used. Comparative analyses were stratified by age and pregnancy status. RESULTS: Experimental evaluation of the assay used revealed a detection limit of 379 genome copies/ml urine. For pooled urine samples, the positive predictive value was 100% whereas the negative predictive value equaled 98.1%. The observed infection prevalence was higher for cervical swabs than for urine samples. Prevalence estimates also differed significantly between pregnant and non-pregnant adolescents (< or = 20 years), irrespective of the test material used (10.2% vs. 7.3% for cervical swabs, 10.9% vs. 6.1% for pooled urine samples). CONCLUSIONS: Our retrospective study, based upon a very large number of females from all parts of Germany, revealed a high infection prevalence in adolescents, particularly in pregnant adolescents, thereby justifying the screening directive of the German GBA.

Graves' disease occurring after surgery of a multinodular goiter: a case report.

The transition of toxic or nodular goiter to Graves' disease is known as a rare side effect of (131)I therapy. Here, we report the case of a 46-year-old German female with posttherapeutical Graves' disease after surgery of a multinodular goiter. Although the major part of the thyroid was excised the patient suffered from manifest Graves' disease including typical clinical and laboratory findings. Prior to surgery, no TSH receptor antibodies were found, although low TPO antibody titres could already be detected. It may thus be assumed that the therapeutic manipulation elicited the key change towards a TSH receptor antibody production in a predisposed organ or alternatively deteriorated a mild unapparent pre-existing Graves' disease. It might be concluded that the possibility of posttherapeutical Graves' disease should be considered in the presence of TPO antibodies prior to the surgical intervention.

Comparative neuro tissue engineering using different nerve guide implants.

At the moment autologous nerve grafting remains the only reasonable technique for reconstruction of peripheral nerve defects. Unfortunately, this technique has a lot of complications and disadvantages. These problems are related to the autologous nerve that is harvested for this procedure. Donor site morbidity with loss of sensitivity, painful neuroma formation and of course the restricted availability of autologous nerves stimulates the idea for alternative techniques on that field. In this paper we describe our experience with different graft materials for reconstruction of a 2 cm nerve gap in a median nerve model in rats. After implantation of various materials (biological/synthetic) the main experiments were conducted with a synthetic, biodegradable nerve conduit seeded with autologous Schwann cells. With this material we were able to reconstruct successfully a 2 cm gap in the rat median nerve. Regeneration with this material was found to be equally to an autologous nerve graft.

[Localisation of parathyroid glands using planar (99m)Tc-sestamibi scintigraphy. Comparison between subtraction- and dual-phase technique]. / Lokalisation von Nebenschilddrüsenadenomen mit planarer (99m)Tc-Sestamibi-Szintigraphie: Vergleich von Subtraktionsund 2-Phasen-Technik.

AIM: In the context of presurgical localisation of parathyroid adenomas in primary hyper-parathyreoidism (pHPT) using (99m)Tc-sestamibi scintigraphy, subtraction- and dualphase technique are compared with each other and with the surgical findings. PATIENTS, METHODS: Prospectively, 126 patients with pHPT were investigated presurgically. For visualisation of parathyroid adenomas, an image of the thyroid ((99m)Tc-pertechnetat) was subtracted from a perfusion image ((99m)Tc-sestamibi) and 2 h p. i. another image was acquired for identification of retention of activity. Considering both techniques the clinical findings were reported promptly. Retrospectively, the evaluations were presented separately to four experienced raters. RESULTS: In clinical routine for 109 patients correct findings were reported presurgically (87%). From 129 resected parathyroid adenomas 118 were localised correctly (sensitivity 91%, positive predictive value 94%). Concerning the retrospective analysis, in 75% of the cases both techniques provided the correct site, in 14% only the dual-phase technique and in 7% only the subtraction-technique was correct. With the help of the dual-phase technique significantly more investigations were correctly rated than with the help of the subtraction technique (88.7 +/- 3.2% vs. 81.6 +/- 1.2%, p < 0.01, two-sided t-test). CONCLUSION: The presurgical scintigraphic localisation of hyperactive parathyroid glands in pHPT assists minimal invasive surgery serving a high rate of correct findings. According to our data the dual-phase technique seems to be more sensitive than the subtraction technique. In some cases, however, the correct site may only be found using the subtraction technique. For an optimal surgical strategy we suggest the combination of both techniques.

[Tissue engineering of peripheral nerves]. / Tissue Engineering peripherer Nerven.

BACKGROUND: In spite of considerable progress in microsurgical techniques, the treatment of long distance defects in peripheral nerves remains challenging for the surgeon. Autologous nerve grafting has been the only applicable procedure to overcome such defects in the past. Due to the known disadvantages of this procedure (neuroma formation and sensory deficits at the donor-site, limited availability of donor-material, etc.) and impaired regenerative results, different tubulisation techniques are discussed more frequently as alternatives to the autologous nerve grafts. AIM OF THE STUDY: In this work, the authors summarise their experiences and results with different synthetically developed materials, cellular and acellular tubes and venous conduits for the reconstruction of peripheral nerve defects. MATERIAL AND METHODS: To analyse peripheral nerve regeneration, we utilised a median nerve model in rats. In these studies nerve gaps up to 40 mm were induced. Guiding tubes of various materials (trimethylene carbonate-epsilon-caprolactone, polyethylene, veins, and collagen) were employed. Furthermore, we introduced Schwann cells as cellular elements into some of the trimethylene carbonate-epsilon-caprolactone tubes. The longest postoperative observation period was nine months. RESULTS: The results demonstrated that only in the case of cellular filled tubes (syngenic Schwann cells) did regeneration occur across the 20 mm gap. This regeneration was comparable to that induced after autologous grafting. Across a 40 mm gap the autologous graft demonstrated the best results.

Depression and anxiety in different thyroid function states.

Previous studies on hypothyroid subjects have indicated serious psychiatric symptoms affecting the patients' quality of life. The present prospective cross-sectional study's aim was to examine these symptoms in thyroid patients with different functional states. A total of 254 patients (age: 56 +/- 14 years [mean +/- standard deviation], 181 female, 73 male) referred to a hospital for radioiodine treatment of hyperthyroidism or for follow-up of differentiated thyroid cancer, respectively, were included. All patients underwent the twelve-item general health questionnaire, which is an instrument for detecting mood disturbances. Euthyroid and hyperthyroid patients did not differ significantly in their general health questionnaire score (11 +/- 5 vs. 11 +/- 7), nor did subclinical hyperthyroid (11 +/- 6) or subclinical hypothyroid subjects (12 +/- 5). In contrast, hypothyroid patients showed a significantly higher mean score (17 +/- 7, p < 0.001, ANOVA). Binary logistic regression revealed that hypothyroidism increases age and gender-adjusted risk for critical mood deterioration by seven-fold. Thus, hypothyroidism represents a widely underestimated functional condition that may severely affect mental health.

Transduction of wild-type merlin into human schwannoma cells decreases schwannoma cell growth and induces apoptosis.

Mutations in both alleles of the tumour suppressor gene coding for merlin/schwannomin, an ERM family protein, cause the hereditary disease neurofibromatosis type 2 (NF2). NF2 is characterized by the development of multiple nervous system tumours especially vestibular schwannomas. Efficient oncoretrovirus-mediated gene transfer of different merlin constructs was used to stably re-express wild-type merlin in primary cells derived from human schwannomas. Using two-parameter FACS analysis we show that expression of wild-type merlin in NF2 cells led to significant reduction of proliferation and G0/G1 arrest in transduced schwannoma cells. In addition, we show increased apoptosis of schwannoma cells transduced with wild-type merlin. Our findings in primary schwannoma cells from NF2 patients strongly support the hypothesis of merlin acting as a tumour suppressor and may help in understanding development of human schwannomas in NF2.

A reliable method to reduce collagen scar formation in the lesioned rat spinal cord.

Following traumatic injury, the formation of a glial scar and deposition of extracellular matrix (ECM) contributes to the regeneration failure in the adult mammalian central nervous system (CNS). Using a postcommissural fornix transection as a brain lesion model in rat, we have previously shown that the collagenous basement membrane (BM) at the lesion site is a major impediment for axon regeneration. Deposition of BM in this lesion model can be delayed by administration of the iron chelator 2,2'-bipyridine (BPY), an inhibitor of prolyl 4-hydroxylase (PH), a key enzyme of collagen biosynthesis. To examine whether this potential therapeutic approach is transferable to other CNS regions, we have chosen the mechanically lesioned rat spinal cord to investigate the effects of BPY administration on BM formation. Due to the close proximity of the lesion zone to meningeal fibroblasts, a cell-type secreting large amounts of collagen IV, BM deposition was much more extensive in the spinal cord than in the brain lesion. Neither immediate injections nor continuous application of BPY resulted in a detectable reduction of BM formation in the spinal cord. Only a combination of anti-scarring treatments including (i) injection of the more potent PH inhibitor [2,2'-bipyridine]-5,5'-dicarboxylic acid (BPY-DCA), (ii) selective inhibition of fibroblast proliferation and ECM production by 8-Br-cAMP, and (iii) continuous application of BPY-DCA, reduced the lesion-induced BM significantly. The present results clearly demonstrate, that the exclusive application of BPY according to a protocol designed for treatment of brain lesions is not sufficient to reduce BM formation in the lesioned adult rat spinal cord.

Cellular localization of the disintegrin CRII-7/rMDC15 mRNA in rat PNS and CNS and regulated expression in postnatal development and after nerve injury.

Disintegrins perform putative functions in cell adhesion, signaling and fusion. We have isolated a 2815-bp rat cDNA (CRII-7) representing a transcript that is differentially expressed during sciatic nerve regeneration. Nucleotide sequence comparison indicates that CRII-7 is the rat homologue to the recently cloned cDNAs MDC15 (ADAM 15) and metargidin (hMDC15) of mouse and human, respectively. The CRII-7 cDNA (rMDC15) encodes a membrane-anchored glycoprotein of approximately 85 kDa containing a disintegrin and a metalloprotease domain. Cellular metalloprotease disintegrins are a family of proteins (ADAMs or MDC proteins) with important roles, e.g., in cell-cell interactions during fertilization, muscle and nerve development, or tumor necrosis factor-alpha (TNF-alpha) cleavage. Northern blot analysis demonstrated a predominant expression of CRII-7/rMDC15 in the nervous system (PNS and CNS) and lung. Analysis of the CRII-7/rMDC15 transcript levels following peripheral nerve lesions demonstrated regulated mRNA expression during Wallerian degeneration and nerve regeneration. The steady-state levels of CRII-7/rMDC15 transcripts markedly increased within the first day after lesion and then steadily decreased for at least 4 weeks. CRII-7/rMDC15 mRNA expression was further examined during postnatal development and maturation of rat sciatic nerve and brain, as well as in cultured Schwann cells, meningeal fibroblasts, and astrocytes. In situ hybridization on paraffin sections showed the cellular localization of CRII-7/rMDC15 mRNA in Schwann cells and endothelial cells of peripheral nerve and in various neuronal populations in brain and spinal cord.

Long-term culture and characterization of human neurofibroma-derived Schwann cells.

Neurofibromas are benign tumors arising from the peripheral nerve sheath and are a typical finding in neurofibromatosis type 1 (NF1). Schwann cells are the predominant cell type in neurofibromas and thus are supposed to play a major role in the pathogenesis of these tumors. It is not known, however, if NF1 mutations in Schwann cells result in an altered phenotype that subsequently leads to tumor formation. To characterize the biological properties of neurofibroma-derived Schwann cells we developed cell culture techniques that enabled us to isolate Schwann cells from neurofibromas and grow them in vitro for several weeks without significant fibroblast contamination. Neurofibroma-derived Schwann cells were characterized by altered morphology, heterogeneous growth behavior, and increased expression of the P0 antigen while several other features of normal human Schwann cells were retained. We conclude that neurofibroma-derived Schwann cells exhibit a distinct phenotype in vitro but that the observed abnormalities by themselves are insufficient to explain neurofibroma formation. Application of our improved culture conditions makes neurofibroma-derived Schwann cells readily available for further studies to define their role in tumorigenesis in neurofibromatosis type 1.

Enhanced proliferation and potassium conductance of Schwann cells isolated from NF2 schwannomas can be reduced by quinidine.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disease that is characterized mainly by schwannomas, as well as menigiomas and gliomas. The NF2 gene product merlin/schwannomin acts as a tumor suppressor. Schwann cells derived from NF2 schwannomas showed an enhanced proliferation rate, and electrophysological studies revealed larger K(+) outward currents as compared with controls. Schwann cells isolated from schwannomas of NF2 patients or multiorgan donors were treated with different concentrations of the K(+) current blockers quinidine, tetraethylammonium chloride, and 4-aminopyridine and K(+) outward currents and proliferation rates of these cells were compared. K(+) outward currents of both cell types can be blocked by quinidine. Importantly, treatment with quinidine reduces proliferation of NF2 Schwann cells in a concentration dependent manner but did not reduce proliferation of normal Schwann cells. Therefore, the use of quinidine or quinidine-like components would possibly provide a novel adjuvant therapeutic option for NF2 patients to slow down or freeze growth of schwannomas.

Glycosaminoglycan-binding properties and secondary structure of the C-terminus of netrin-1.

Netrins are soluble neurite-outgrowth-promoting proteins related to the laminin B2 chain. Since these proteins and their receptor DCC (the "deleted in colorectal carcinoma" gene product) bind heparin, glycosaminoglycans may modulate their biological actions in a similar fashion as described for several other ligand-receptor systems. Here we show that a polypeptide encompassing the C-terminal cluster of basic amino acids of netrin-1 (i) adopts an alpha-helical conformation in water-trifluoroethanol mixtures according to circular dichroism experiments and (ii) binds electrostatically to heparin with high affinity under physiological ionic conditions (K(D) = 15 nM for the binding to immobilized heparin according to surface plasmon resonance, K(D) = 50 nM in solution as determined with isothermal titration calorimetry). These data indicate that the cluster of basic amino acids at the C-terminus of netrin-1 forms an alpha-helical structural element which can contribute to the glycosaminoglycan-binding activity of this neurotrophic guidance molecule.

Mutation-dependent alteration in cellular distribution of peripheral myelin protein 22 in nerve biopsies from Charcot-Marie-Tooth type 1A.

The hereditary demyelinating neuropathy Charcot-Marie-Tooth type 1A is caused by duplication or by point mutations of the PMP22 gene. Histopathological differences in these genotypes suggest distinct disease mechanisms. In the present investigation we demonstrate a pathologically altered cellular distribution of PMP22 in sural nerve biopsies of patients with PMP22 point mutations. In these patients, in contrast to findings in patients with PMP22 duplication, PMP22 partially accumulates in the Schwann cells instead of being inserted in the myelin sheath. These findings may explain the different histopathology and may suggest different mechanisms of pathogenesis in these genotypes.

Rho-dependent regulation of cell spreading by the tetraspan membrane protein Gas3/PMP22.

Gas3/PMP22 plays a crucial role in regulating myelin formation and maintenance, and different genetic alterations in gas3/PMP22 are responsible for a set of human peripheral neuropathies. We have previously demonstrated that Gas3/PMP22 could regulate susceptibility to apoptosis in NIH3T3 cells but not in REF 52 cells. In this report we demonstrate that when the apoptotic response triggered by gas3/PMP22 was counteracted by Bcl-2 coexpression, morphological changes were observed. Time-lapse analysis confirmed that Gas3/PMP22 can modulate cell spreading, and this effect was strengthened after inhibition of phosphoinositide 3-kinase. Using the active form of the small GTPase RhoA, we have been able to dissect the different Gas3/PMP22 biological activities. RhoA counteracted the Gas3/PMP22-dependent morphological response but was unable to neutralize the apoptotic response. Treatment of NIH3T3 cells with cytotoxic necrotizing factor 1, which activates endogenous Rho, also counteracted Gas3/PMP22-mediated cell shape and spreading changes. Treatment of REF 52 cells, which are unresponsive to Gas3/PMP22 overexpression, with the C3 exoenzyme, inhibiting Rho activity, renders REF 52 cells responsive to Gas3/PMP22 overexpression for cell shape and spreading changes. Finally, assembly of stress fibers and focal adhesions complexes, in response to lysophosphatidic acid-induced endogenous Rho activation, was impaired in Gas3/PMP22-overexpressing cells. We hypothesize that cell shape and spreading regulated by Gas3/PMP22 through the Rho GTPase might have an important role during Schwann cells differentiation and myelinization.

Post-transcriptional regulation of the peripheral myelin protein gene PMP22/gas3.

The peripheral myelin protein PMP22 gene has been described as a growth arrest-specific gene gas3 and has been identified as disease gene of various demyelinating neuropathies. The gene consists of two highly conserved alternative noncoding 5'-exons la (CD25) and 1b (SR13), respectively. Differential expression patterns of these transcripts in vivo and in vitro suggest a very complex mode of PMP22 gene regulation, which cannot be explained merely by transcriptional control. In fact, the PMP22 gene is regulated on different post-transcriptional levels. While reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed no alterations in stability for both PMP22 transcripts in randomly growing Schwann cell cultures of rat sciatic nerve for at least 8 hours, in serum-induced synchronized cultures of resting cells we observed a specific cell cycle-regulated degradation of both transcripts. We further prepared diverse PMP22/CAT fusion genes to study the influence of the alternative 5'UTRs on PMP22 translation. Transient transfection of NIH3T3-fibroblasts and rat Schwann cells demonstrated that the alternative 5'UTRs (CD25 and SR13) and the 3'UTR exert differential regulatory influences on the translation efficiency.

Major histocompatibility complex class II expression and macrophage responses in genetically proven Charcot-Marie-Tooth type 1 and hereditary neuropathy with liability to pressure palsies.

This study examined major histocompatibility complex (MHC) class II expression and macrophage infiltration in sural nerve biopsies from patients with genetically proven Charcot-Marie-Tooth (CMT) 1A and 1B and hereditary neuropathy with liability to pressure palsies (HNPP) by immunocytochemistry. In both young and older patients with duplication of the PMP22 gene, MHC class II expression was consistently up-regulated and not closely related to the extent of macrophage infiltration. On the other hand, MHC class II expression was more variable in CMT1A and CMT1B caused by point mutations and in HNPP. The extent of nerve pathology as assessed by teased fiber preparations or electron microscopy was not predictive for the degree of MHC class II expression in CMT1/HNPP. We conclude that MHC class II up-regulation is a common feature in hereditary neuropathies. As shown for the animal model of globoid cell dystrophy, it is conceivable that increased expression of MHC class II molecules in CMT1 and HNPP accelerates nerve pathology.

Voltage-dependent membrane currents of cultured human neurofibromatosis type 2 Schwann cells.

Previous experimental observations indicate that inhibition of voltage-dependent K+ currents suppresses proliferation of normal Schwann cells. In the present study we tested the opposite relationship, i.e., whether Schwann cells from tumors with abnormally high rates of proliferation would have an increase in membrane K+ currents. Whole-cell membrane currents were studied in cultured cells from schwannomas of two neurofibromatosis type 2 (NF2) patients (n = 53), one patient with a sporadic schwannoma (n = 22), and two control subjects (n = 41). Five different types of voltage-dependent membrane currents were found in all of the Schwann cells tested. Membrane depolarization activated outward K+ and Cl- currents; quinidine was found to block the K+ current (IC50 approximately 1 microM), and NPPB reduced the Cl- current. Ba2+-sensitive inward rectifier K+ currents, fast Na+ currents, and a transient, inactivating K+ current were less frequently observed. On average, NF2 cells were found to have statistically significant higher membrane potential and larger non-inactivating K+ outward current as compared to controls. Electrophysiological parameters of Schwann cells from a sporadic schwannoma showed a tendency for larger outward currents; however, the difference did not reach statistical significance. Together the data support the suggestion of a possible link between K+ outward current and proliferation of Schwann cells.

Isolation and characterization of Schwann cells from neurofibromatosis type 2 patients.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disease of the nervous system characterized by multiple schwannomas. The NF2 gene product, termed schwannomin or merlin, was hypothesized to function as a cytoskeleton-membrane linking protein due to homology to members of the protein 4.1 superfamily and to function as a tumor suppressor. We isolated and characterized pure Schwann cell cultures from schwannomas derived from neurofibromatosis 2 patients with identified germline mutations and loss of heterozygosity. We describe striking differences between NF2 and control Schwann cells in morphology, cell-cell contacts, and growth. NF2 Schwann cells form multiple long processes with filopodial and lamellopodial extensions. NF2 Schwann cells lack contact inhibition, grow in multiple layers, and show a higher proliferation rate than control cells. For the first time Schwann cells derived from patients with the NF2 genotype were cultured and characterized in vitro. These cultures are highly valuable for investigating the effects of NF2 mutations and the development of therapies.