Infection of Glia by Human Pegivirus Suppresses Peroxisomal and Antiviral Signaling Pathways.

Human pegivirus (HPgV) infects peripheral leukocytes but was recently shown to be a neurotropic virus associated with leukoencephalitis in humans. In the present study, we investigated the neural cell tropism of HPgV as well as its effects on host immune responses. HPgV wild type (WT) and a mutant virus with a deletion in the HPgV NS2 gene (ΔNS2) were able to productively infect human astrocytes and microglia but not neurons or an oligodendrocyte-derived cell line. Of note, the ΔNS2 virus replicated better than WT pegivirus in astrocytes, with both viruses being able to subsequently infect and spread in fresh human astrocyte cultures. Infection of human glia by HPgV WT and ΔNS2 viruses resulted in suppression of peroxisome-associated genes, including PEX11B, ABCD1, PEX7, ABCD3, PEX3, and PEX5L, during peak viral production, which was accompanied by reduced expression of IFNB, IRF3, IRF1, and MAVS, particularly in ΔNS2-infected cells. These data were consistent with analyses of brain tissue from patients infected with HPgV in which we observed suppression of peroxisome and type I interferon gene transcripts, including PEX11B, ABCD3, IRF1, and IRF3, with concurrent loss of PMP70 immunoreactivity in glia. Our data indicate that human astrocytes and microglia are permissive to HPgV infection, resulting in peroxisome injury and suppressed antiviral signaling that is influenced by viral diversity. IMPORTANCE Human pegiviruses are detected in 1 to 5% of the general population, principally infecting leukocytes, although their effects on human health remain uncertain. Here, we show that human pegivirus infects specific neural cell types in culture and human brain and, like other neurotropic flaviviruses, causes suppression of peroxisome and antiviral signaling pathways, which could favor ongoing viral infection and perhaps confer susceptibility to the development of neurological disease.

Absent in melanoma 2 regulates tumor cell proliferation in glioblastoma multiforme.

INTRODUCTION: Inflammation is a key aspect of glioblastoma multiforme (GBM) although it remains unclear how it contributes to GBM pathogenesis. Inflammasomes are intracellular multi-protein complexes that are involved in innate immunity and are activated by cellular stress, principally in macrophages. This study examined the expression of inflammasome-associated genes in GBM, particularly absent in melanoma 2 (AIM2). METHODS: Tissue samples from surgically-resected GBM tumors (n = 10) were compared to resected brain specimens from patients with epilepsy (age- and sex-matched Other Disease Controls (ODC, n=5)) by qRT-PCR, western blotting and immunofluorescence. Gene expression studies in human astrocytoma U251 cells were performed and the effects of deleting the absent in melanoma 2 (AIM2) gene using the CRISPR-Cas9 system were analyzed. RESULTS: GBM tissues showed significantly elevated expression of multiple immune (CD3E, CD163, CD68, MX1, ARG1) and inflammasome (AIM2, NLRP1, IL18, CASP1, and IL-33) genes compared to ODC tissues, without induction of IL1B, IFNG or TNFA. An insert-containing AIM2 variant transcript was highly expressed in GBM tissues and in U251 cells. AIM2 immunoreactivity was concentrated in the tumor core in the absence of PCNA immunodetection and showed a predominant 52 kDa immunoreactive band on western blot. Deletion of AIM2 resulted in significantly enhanced proliferation of U251 cells, which also displayed increased resistance to temozolomide treatment. CONCLUSIONS: GBM tumors express a distinct profile of inflammasome-associated genes in a tumor-specific manner. AIM2 expression in tumor cells suppressed cell proliferation while also conferring increased susceptibility to contemporary GBM therapy.

Rapid Multifocal Neurologic Decline in an Immunocompromised Patient.

A man in his early 70s with a diagnosis of chronic lymphocytic leukemia and being treated with prednisone, fludarabine, cyclophosphamide, and rituximab presented with progressive multifocal neurologic decline. The patient died 2 months after the onset of this decline despite extensive clinical and laboratory investigation and a trial of methylprednisolone therapy. The approach to the immunosuppressed patient with progressive neurologic decline, neuropathologic findings, and final diagnosis are discussed.

Confocal neurolasermicroscopy in human brain - perspectives for neurosurgery on a cellular level (including additional comments to this article).

BACKGROUND: During neurosurgery intraoperative imaging of vital neural structures on a cellular level would facilitate the development of new strategies for diagnosis and treatment. In vivo imaging would permit the detection of the tumour centre and infiltration zone. With targeted biopsies the lesion of interest could be determined before performing the biopsy, facilitating the final pathological diagnosis. In this study we present confocal neurolasermicroscopy as a new method in neurosurgery. METHODS: A miniaturised confocal neurolasermicroscope (NLM) was used ex vivo immediately after tumour resection of glioblastoma multiforme (GBM). NLM was performed with subcellular magnification up to a tissue depth of 100 microm. NLM images were compared to conventional histological images of the same tumour. RESULTS: The application of the method in nine patients allowed adequate diagnosis of a malignant glioma fulfilling the WHO criteria when compared to conventional histology. In one patient with glioblastoma multiforme NLM allowed the correct diagnosis of GBM to be made, demonstrating the high mitotic rate and cell pleomorphy of the tumour cells. Additional characteristics such as pleomorphic cells, mitotic figures, fibrillary matrix and the distinction between tumour centre and infiltration zone could be shown. CONCLUSIONS: NLM is a tool which could be adapted for neurosurgical intraoperative applications with the potential to diagnose tumours and recognise the tumour centre and infiltration zone in vivo. Further applications of NLM to characterise subcellular structures and vascular architecture are possible.

[Neurotuberculosis: a continuing clinical challenge]. / Neurotuberkulose : Eine anhaltende klinische Herausforderung.

In Germany neurotuberculosis is quite rare. Familiarity with the disease is nonetheless important because of many differential diagnoses and therapeutic implications. The diagnosis of neurotuberculosis is made by considering of clinical presentation, CSF, and cerebral imaging. Early diagnosis, prompt initiation of effective antitubercular therapy, and clinical staging are necessary for establishing a long-term treatment prognosis. The results of neurotuberculosis therapy are often unsatisfactory despite the availability of effective drugs. Lasting damage or death can be averted in fewer than half of the patients. Studies now confirm that early adjuvant corticoid therapy reduces lethality and morbidity. Resistant new strains of the pathogen, Mycobacterium tuberculosis, complicate therapy. Recent discoveries especially in diagnosis and therapy are explained using case evidence.

[Progressive muscle atrophy. A rarely diagnosed variant of amyotrophic lateral sclerosis]. / Progressive Muskelatrophie. Eine unterdiagnostizierte Variante der amyotrophen Lateralsklerose.

Progressive muscle atrophy (PMA) is a degenerative disease of the lower motor neuron. The course of the illness and the fatal prognosis correspond to those of amyotrophic lateral sclerosis (ALS). Neuropathologic and genetic findings support categorizing PMA within the spectrum of ALS, even though no clinical sign of a disorder of the upper motor neuron is demonstrable. The diagnosis of PMA is based on advanced extremity pareses and atrophies with a high progression rate. Respiratory insufficiency is determinative of the prognosis. Absent or late affection of bulbar functions is characteristic of the disease. Intraneuronal bunina bodies and ubiquitine-positive inclusions, which are established morphologic characteristics of ALS, are found post mortem. The treatment options of riluzol medication, respiratory therapy, and nutrition are analogous to those for typical ALS.

Muscle and nerve pathology in Dunnigan familial partial lipodystrophy.

OBJECTIVE: To characterize muscle and nerve pathology in Dunnigan familial partial lipodystrophy (FPLD). METHODS: We used conventional histology, immunohistochemistry, messenger RNA (mRNA) expression, gene sequencing, and clinical studies of 13 patients with neuromuscular involvement. RESULTS: The clinical findings consisted of muscle hypertrophy (12/13), severe myalgias (9/13), and multiple nerve entrapment syndromes (8/13). Skeletal muscle histology demonstrated marked Type 1 and 2 muscle fiber hypertrophy and nonspecific myopathic changes, whereas numerous paranodal myelin swellings (tomacula) were found in sural nerve biopsies. We found that myostatin mRNA expression was reduced in patients with FPLD vs controls. We sequenced the myostatin gene in our subjects, but found no mutations. We then investigated whether or not SMAD, the intracellular mediator of myostatin signaling, might be impaired in patients with FPLD. We found that in FPLD muscle, a large number of SMAD molecules adhered to the nuclear membrane and were not found within the nucleus, compared with normal muscle or muscle from a patient with a non-FPLD lamin A/C disease. CONCLUSION: The myopathy and neuropathy associated with Dunnigan familial partial lipodystrophy are distinct from other lamin A/C disorders. We hypothesize that the lipodystrophy-associated mutation interferes with SMAD signaling, linking this type of lipodystrophy to the phenotypically similar myostatin deficiency.

[Polyarteritis nodosa - a "classical" case]. / Panarteritis nodosa - ein "klassischer" Fall.

Diagnosis of polyarteritis nodosa is often delayed due to the vast heterogeneity of initial clinical symptoms. The case presented shows the clinical image of the disease, leading from the first symptoms up to verification of the diagnosis by sural-nerve biopsy. We discuss the classification of the disease among other types of vasculitis, the classification criteria proposed by the American College of Rheumatology (ACR) as well as current therapeutic options. This case underlines the interdisciplinary character of the disease, challenging neurologists, dermatologists, rheumatologists and orthopedics alike.

Plastic bronchitis in children with Fontan palliation: analogue to protein losing enteropathy?

We studied a 6-year-old boy and a 2-year-old girl with bronchitis fibroplastica following Fontan operation. Large endobronchial casts of rubber-like consistency resulted in life-threatening pulmonary failure. In one patient symptoms improved after optimizing heart function with diuretics, and in the other a dramatic improvement with the resolution of the clinical symptoms and normalized serum albumin followed subcutaneous high-molecular-weight heparin treatment. The severe relapse after discontinuation of the heparin medication and the once more successful treatment with heparin suggest that in addition to optimizing heart function, high-molecular-weight heparin might be a therapeutic option for this poorly understood condition.