Protein kinase C regulates AMPA receptor auxiliary protein Shisa9/CKAMP44 through interactions with neuronal scaffold PICK1

Synaptic α‐amino‐3‐hydroxyl‐5‐methyl‐4‐isoxazole‐propionate (AMPA) receptors are essential mediators of neurotransmission in the central nervous system. Shisa9/cysteine‐knot AMPAR modulating protein 44 (CKAMP44) is a transmembrane protein recently found to be present in AMPA receptor‐associated protein complexes. Here, we show that the cytosolic tail of Shisa9/CKAMP44 interacts with multiple scaffold proteins that are important for regulating synaptic plasticity in central neurons. We focussed on the interaction with the scaffold protein PICK1, which facilitates the formation of a tripartite complex with the protein kinase C (PKC) and thereby regulates phosphorylation of Shisa9/CKAMP44 C‐terminal residues. This work has implications for our understanding of how PICK1 modulates AMPAR‐mediated transmission and plasticity and also highlights a novel function of PKC.

Colony-stimulating factor-1 mediates macrophage-related neural damage in a model for Charcot-Marie-Tooth disease type 1X

Previous studies in our laboratory have shown that in models for three distinct forms of the inherited and incurable nerve disorder, Charcot-Marie-Tooth neuropathy, low-grade inflammation implicating phagocytosing macrophages mediates demyelination and perturbation of axons. In the present study, we focus on colony-stimulating factor-1, a cytokine implicated in macrophage differentiation, activation and proliferation and fostering neural damage in a model for Charcot-Marie-Tooth neuropathy 1B. By crossbreeding a model for the X-linked form of Charcot-Marie-Tooth neuropathy with osteopetrotic mice, a spontaneous null mutant for colony-stimulating factor-1, we demonstrate a robust and persistent amelioration of demyelination and axon perturbation. Furthermore, functionally important domains of the peripheral nervous system, such as juxtaparanodes and presynaptic terminals, were preserved in the absence of colony-stimulating factor-1-dependent macrophage activation. As opposed to other Schwann cell-derived cytokines, colony-stimulating factor-1 is expressed by endoneurial fibroblasts, as revealed by in situ hybridization, immunocytochemistry and detection of β-galactosidase expression driven by the colony-stimulating factor-1 promoter. By both light and electron microscopic studies, we detected extended cell-cell contacts between the colony-stimulating factor-1-expressing fibroblasts and endoneurial macrophages as a putative prerequisite for the effective and constant activation of macrophages by fibroblasts in the chronically diseased nerve. Interestingly, in human biopsies from patients with Charcot-Marie-Tooth type 1, we also found frequent cell-cell contacts between macrophages and endoneurial fibroblasts and identified the latter as main source for colony-stimulating factor-1. Therefore, our study provides strong evidence for a similarly pathogenic role of colony-stimulating factor-1 in genetically mediated demyelination in mice and Charcot-Marie-Tooth type 1 disease in humans. Thus, colony-stimulating factor-1 or its cognate receptor are promising target molecules for treating the detrimental, low-grade inflammation of several inherited neuropathies in humans.

Predictors of length of stay in inpatient child and adolescent psychiatry: failure to validate an evidence-based model

OBJECTIVE

To test if predictors of length of stay are based on empirical evidence.

METHOD

1001 regularly terminated treatment episodes from 13 child and adolescent psychiatric hospitals were analysed. In order to cross- validate the results, the sample was randomly divided into a definition sample (n = 500) and a validation sample (n = 501). The variables in the definition sample were screened statistically for their suitability as predictors of logarithmic length of stay (logLOS). Variables shown to be significant and uncorrelated were entered into multifactor analyses of variance in order to generate the model with the largest amount of explained variance of logLOS. Subsequently the results were tested against the validation sample.

RESULTS

In the definition sample we found the three predictor variables admission as crisis intervention, out of home dispositions and psychoanalytic therapy which could explain 23.7 % of the variance of logLOS. Unfortunately, this could not be replicated in the validation sample as a model.

CONCLUSION

Simple models of prediction of LOS in the field of child and adolescent psychiatry cannot be reliably based on empirical evidence. The main consequence is that fixed disorder-related reimbursement systems do not seem justified.

Evaluation of sensorimotor training in children with ADHD

Reduced ability to regulate motor behavior seems to be an essential aspect of Attention-Deficit Hyperactivity Disorder (ADHD) and may reflect deficits in behavioral response inhibition. In this respect, pragmatic clinical experience over the last two decades, in daily practice, training of motor control has played an important role within multimodal treatment approaches, although an adequate proof of its efficacy is still lacking. Therefore, to examine the efficacy of sensorimotor training, 12 children with ADHD (two groups of six) were treated with both sensorimotor training and (as control) cognitive behavioral training using a within-subject cross-over design. Each treatment had a duration of 4 months (20 sessions), yielding a total of 40 sessions for the completed cross-over design. Results showed that Sensorimotor Training improved sensorimotor coordination slightly, while Cognitive Behavioral Training ameliorated cognitive impulse control. Hyperactivity and anxious-depressive/aggressive behavior were markedly reduced by Sensorimotor Training but not by Cognitive Behavioral Training. In conclusion, a combined treatment may be recommended since compensation and regulation of inhibitory deficits in ADHD come into play within the framework of both kinds of training.

[Radiologic changes following cement-free implantation of hip prostheses. 5-year follow-up and clinical experience with the cement-free hip prosthesis Autophor-900-S]

PURPOSE

To evaluate early reliable radiographic signs of loosening in cementless total hip arthroplasty compared to clinical follow-up.

METHODS

Within a time interval of 5 years 89 patients with 101 hips underwent total hip arthroplasty using the Autophor 900 S-prosthesis. Clinical and radiographic follow-up were first performed retrospectively followed by a prospective investigation.

RESULTS

Radiographic evaluation showed prosthesis fixation in 93%. Loosening of the prosthesis was identified in 4 cases of the acetabular component and in 4 cases of the femoral stem. Pain was associated with radiographically detectable loosening of the cementless arthroplastic components in only two cases.

CONCLUSION

Within a follow-up period of up to five years, loosening of cementless total hip arthroplasty occurs in about 7%. The most reliable radiographic signs of loosening are complete radiolucent zones wider than 2 mm at the bone-component interface, progressive subsidence, migration, or tilt of the component. Pain and movement disorders are not specific symptoms and do not necessarily indicate a loosening of the prosthesis.

[A case of actinomycosis of the fallopian tube (author's transl)]

Reported is the rare case of an actinomycosis of the right Fallopian tube. The clinical picture is characterized by a comparatively sudden onset of abdominal pain, obstipation and feaver as well as a markedly increased ESR. Good co-operation between the various clinical disciplines (urology, surgery, internal medicine, gynecology) lead to an exact preoperative localization of the scaring and infiltrating process that is then verified by laparotomy. The right adnexae show massive inflammatory infiltrates and form a conglomerate tumor with the adjacent sigma and appendix. Characteristic actinomycetic druses are found histologically only in the right Fallopian tube. On the left side a florid non-specific salpingitis is antibiotics is withoug complications. Mode of infection, differential diagnosis and prognosis that is dependent on a correct diagnosis at an early stage are discussed.