Paraneoplastic NMDA encephalitis, a case report and an extensive review of available literature

Anti-N-methyl-D-aspartate receptor (NMDAr) encephalitis is a prevalent autoimmune condition marked by diverse neuropsychiatric symptoms, primarily impacting young females. The exact mechanisms underlying the development of NMDAr encephalitis have not been fully elucidated. Nonetheless, studies have demonstrated that auto-antibodies targeting the NR1-NR2 subunits of the NMDAr can trigger receptor dysfunction within the central nervous system, thus giving rise to the associated symptoms. Notably, an association exists between NMDAr encephalitis and an underlying neoplastic condition, with approximately 38% of cases exhibiting this paraneoplastic relationship with ovarian teratomas being the most commonly associated malignancy. While the association between NMDAr encephalitis and renal cell carcinoma (RCC) is exceedingly rare. This case report presents the clinical scenario of a 20-year-old female patient diagnosed with NMDAr encephalitis in conjunction with RCC discovered incidentally on a CT abdomen and pelvis performed to rule out an ovarian teratoma. The presented case underscores the importance of adopting a multidisciplinary approach in the diagnosis and treatment of NMDAr encephalitis, particularly when it is linked to an underlying malignancy. Furthermore, it emphasizes the significance of expanding our understanding of the molecular pathogenesis of NMDAr encephalitis to enhance patient care and optimize clinical outcomes. Additionally, a comprehensive review of the existing literature is included, summarizing all reported malignancies associated with NMDAr encephalitis.

Anti-synthetase syndrome-associated pulmonary veno-occlusive disease

Pulmonary arterial hypertension has been reported with a prevalence of 7.9% in patients with anti-synthetase syndrome; however, anti-synthetase syndrome associated with pulmonary veno-occlusive disease (PVOD) has never before been described in the literature. We present a novel case of anti-synthetase syndrome-associated PVOD in a patient who presented with hypoxic respiratory failure associated with right heart failure and was diagnosed with anti-synthetase syndrome based on his autoimmune serology and pre-capillary pulmonary hypertension on right heart catheterization. He was initiated on pulmonary arterial hypertension therapy, but with escalating dose of parenteral epoprostenol, experienced acute clinical worsening with chest imaging concerning for PVOD that was confirmed on autopsy. Anti-synthetase syndrome can be associated with PVOD, and it should be suspected in patients who have evidence of pre-capillary pulmonary hypertension and who deteriorate with the initiation of pulmonary hypertension-specific therapy.

Defining Plasma MicroRNAs Associated With Cognitive Impairment In HIV-Infected Patients

Human Immunodeficiency Virus (HIV)-infected individuals are at increased risk for developing neurocognitive disorders and depression. These conditions collectively affect more than 50% of people living with HIV/AIDS and adversely impact adherence to HIV therapy. Thus, identification of early markers of neurocognitive impairment could lead to interventions that improve psychosocial functioning and slow or reverse disease progression through improved treatment adherence. Evidence has accumulated for the role and function of microRNAs in normal and pathological conditions. We have optimized a protocol to profile microRNAs in body fluids. Using this methodology, we have profiled plasma microRNA expression for 30 age-matched, HIV-infected (HIV(+) ) patients and identified highly sensitive and specific microRNA signatures distinguishing HIV(+) patients with cognitive impairment from those without cognitive impairment. These results justify follow-on studies to determine whether plasma microRNA signatures can be used as a screening or prognostic tool for HIV(+) patients with neurocognitive impairment. J. Cell. Physiol. 231: 829-836, 2016. © 2015 Wiley Periodicals, Inc.

HIV-1-Tat Protein Inhibits SC35-mediated Tau Exon 10 Inclusion through Up-regulation of DYRK1A Kinase

The HIV-1 transactivator protein Tat is implicated in the neuronal damage that contributes to neurocognitive impairment affecting people living with HIV/AIDS. Aberrant splicing of TAU exon 10 results in tauopathies characterized by alterations in the proportion of TAU isoforms containing three (3R) or four (4R) microtubule-binding repeats. The splicing factor SC35/SRSF2 binds to nuclear RNA and facilitates the incorporation of exon 10 in the TAU molecule. Here, we utilized clinical samples, an animal model, and neuronal cell cultures and found that Tat promotes TAU 3R up-regulation through increased levels of phosphorylated SC35, which is retained in nuclear speckles. This mechanism involved Tat-mediated increased expression of DYRK1A and was prevented by DYRK1A silencing. In addition, we found that Tat associates with TAU RNA, further demonstrating that Tat interferes with host RNA metabolism in the absence of viral infection. Altogether, our data unravel a novel mechanism of Tat-mediated neuronal toxicity through dysregulation of the SC35-dependent alternative splicing of TAU exon 10. Furthermore, the increased immunostaining of DYRK1A in HIV+ brains without pathology points at dysregulation of DYRK1A as an early event in the neuronal complications of HIV infection.

Cerebrospinal fluid MicroRNA profiling using quantitative real time PCR

MicroRNAs (miRNAs) constitute a potent layer of gene regulation by guiding RISC to target sites located on mRNAs and, consequently, by modulating their translational repression. Changes in miRNA expression have been shown to be involved in the development of all major complex diseases. Furthermore, recent findings showed that miRNAs can be secreted to the extracellular environment and enter the bloodstream and other body fluids where they can circulate with high stability. The function of such circulating miRNAs remains largely elusive, but systematic high throughput approaches, such as miRNA profiling arrays, have lead to the identification of miRNA signatures in several pathological conditions, including neurodegenerative disorders and several types of cancers. In this context, the identification of miRNA expression profile in the cerebrospinal fluid, as reported in our recent study, makes miRNAs attractive candidates for biomarker analysis. There are several tools available for profiling microRNAs, such as microarrays, quantitative real-time PCR (qPCR), and deep sequencing. Here, we describe a sensitive method to profile microRNAs in cerebrospinal fluids by quantitative real-time PCR. We used the Exiqon microRNA ready-to-use PCR human panels I and II V2.R, which allows detection of 742 unique human microRNAs. We performed the arrays in triplicate runs and we processed and analyzed data using the GenEx Professional 5 software. Using this protocol, we have successfully profiled microRNAs in various types of cell lines and primary cells, CSF, plasma, and formalin-fixed paraffin-embedded tissues.

Cerebrospinal fluid miRNA profile in HIV-encephalitis

MicroRNAs are short non-coding RNAs that modulate gene expression by translational repression. Because of their high stability in intracellular as well as extracellular environments, miRNAs have recently emerged as important biomarkers in several human diseases. However, they have not been tested in the cerebrospinal fluid (CSF) of HIV-1 positive individuals. Here, we present results of a study aimed at determining the feasibility of detecting miRNAs in the CSF of HIV-infected individuals with and without encephalitis (HIVE). We also evaluated similarities and differences between CSF and brain tissue miRNAs in the same clinical setting. We utilized a high throughput approach of miRNA detection arrays and identified differentially expressed miRNAs in the frontal cortex of three cases each of HIV+, HIVE, and HIV- controls, and CSF of 10 HIV-positive and 10 HIV-negative individuals. For the CSF samples, the group of HIV+ individuals contained nine cases of HIV-associated neurological disorders (HAND) and, among those, four had HIVE. All the HIV-negative samples had non-viral acute disseminate encephalomyelitis. A total of 66 miRNAs were found differentially regulated in HIV+ compared to HIV- groups. The greatest difference in miRNA expression was observed when four cases of HIVE were compared to five non-HIVE cases, previously normalized with the HIV-negative group. After statistical analyses, 11 miRNAs were fund significantly up-regulated in HIVE. Although more clinical samples should be examined, this work represents the first report of CSF miRNAs in HIV-infection and offers the basis for future investigation.

Analyzing habituation responses to novelty in zebrafish (Danio rerio)

Analysis of habituation is widely used to characterize animal cognitive phenotypes and their modulation. Although zebrafish (Danio rerio) are increasingly utilized in neurobehavioral research, their habituation responses have not been extensively investigated. Utilizing the novel tank test, we examine intra- and inter-session habituation and demonstrate robust habituation responses in adult zebrafish. Analyzing the intra-session habituation to novelty further, we also show that selected anxiogenic drugs (caffeine, pentylenetetrazole), as well as stress-inducing alarm pheromone, attenuated zebrafish habituation. Some acute anxiolytic agents, such as morphine and ethanol, while predictably reducing zebrafish anxiety, had no effects on habituation. Chronic ethanol and fluoxetine treatments improved intra-session habituation in zebrafish. In general, our study parallels literature on rodent habituation responses to novelty, and reconfirms zebrafish as a promising model for cognitive neurobehavioral research.

Benign retroperitoneal schwannoma

A rare case of benign retroperitoneal schwannoma in a 76-year-old man is reported. Ultrasound and computerized tomography disclosed two cystic retroperitoneal tumors sized 12 cm and 7 cm. The larger tumor was located anterior to psoas muscle and the smaller one was within the muscle. The larger tumor was excised via laparotomy. After 3.5 years follow-up the intramuscular tumor has remained unchanged and the patient has no symptoms.