A neuronal aging pattern unique to humans and common chimpanzees

Lipofuscin pigment accumulation is among the most prominent markers of cellular aging in postmitotic cells. The formation of lipofuscin is related to oxidative enzymatic activity and free radical-induced lipid peroxidation. In various mammals such as rat, dog, macaque as well as in cheirogaleid primates, most of the large neurons, such as cerebellar Purkinje cells and neocortical pyramidal cells, show heavy lipofuscin accumulation in adulthood. In contrast, a well-known yet poorly studied feature of the aging human brain is that although lipofuscin accumulation is most marked in large neurons of the cerebral cortex, the large neurons of the cerebellar cortex—the Purkinje cells—appear to remain free of lipofuscin accumulation. It is however, not known whether this characteristic of human Purkinje cells is shared with other primates or other mammals. This study reports results from histological observation of Purkinje cells in humans, non-human primates, and other mammals. Procedures include histochemistry, immunocytochemistry, and fluorescence microscopy. Abundant lipofuscin deposition was observed in Purkinje cells of all the species we examined except Homo sapiens (including Alzheimer’s disease cases) and Pan troglodytes. In contrast, lipofuscin deposition was observed in neurons of the dentate nucleus. Our findings suggest that when compared with other primates, Purkinje cells in chimpanzees and humans might share a common aging pattern that involves mechanisms for neuroprotection. This observation is important when considering animal models of aging.     

Lost in translation? A critical look at the role that animal models of obsessive compulsive disorder play in current drug discovery strategies

Introduction: Obsessive-compulsive disorder (OCD) is a severe neuropsychiatric illness estimated to affect between 1–3% of the population. In today’s literature, there are a number well-validated and convincing animal models of OCD described.

Areas covered: Herein, the authors look at the role that animal models of OCD (including transgenic models, deer mouse stereotypy, quinpirole sensitization, post-training signal attenuation, and mouse marble burying) have played in determining the current directions of OCD drug discovery. Specifically, the article reviews new OCD drug therapies currently under investigation including drugs that target glutamate, dopamine, serotonin, and endocannabinoid systems. The authors review the published results of these clinical trials, and critically examine the contribution of animal models to the development of these novel therapies.

Expert opinion: Nitric oxide inhibitors, oxycarbazepine, and modulators of serotonin and metabotropic glutamate receptors should be further explored in animal models as well as in clinical trials. Pregabalin, topiramate, lamotrigine, sarcosine, minocycline, L-carnosine, celecoxib, and ondansetron, which have shown promise in clinical trials, should be explored in animal models with the goal of understanding the neurobiology of their effects. A multidisciplinary, interactive approach to OCD drug discovery, where animal models generate neurobiological hypotheses that can be tested in the clinic, and vice versa, should be cultivated.     

Does the hip positioning matter for oblique lumbar interbody fusion approach? A morphometric study

European Spine Journal - To evaluate whether left hip positioning widened the access corridor using oblique lateral interbody fusion (OLIF) approach during right lateral decubitus (RLD). Ten...     

Presentation of cauda equina syndrome due to an intradural extramedullary abscess: a case report

Background contextCauda equina syndrome is caused by compression or injury to the nerve roots distal to the level of the spinal cord. This syndrome presents as low back pain, motor and sensory deficits in the lower extremities, and bladder as well as bowel dysfunction. Although various etiologies of cauda equina syndrome have been reported, a less common cause is infection.PurposeTo report a case of cauda equina syndrome caused by infection of an intradural extramedullary abscess with Staphylococcus aureus.Study design/settingCase report and review of the literature.MethodsThe literature regarding the infectious causes of cauda equina syndrome was reviewed and a case of cauda equina syndrome caused by infection of an intradural extramedullary abscess with Staphylococcus aureus was reported.ResultsA 37-year-old woman, with history of intravenous drug abuse, hepatitis C, and hepatitis B, presented with low back pain lasting 2 months, lower extremity pain, left greater than right with increasing weakness and difficulty ambulating, and urinary and fecal incontinence. Her presentation was consistent with cauda equina syndrome. The patient underwent a T12–L2 laminectomy, and intradural exploration revealed an abscess. Methicillin-resistant Staphylococcus aureus was found on wound culture.ConclusionsCauda equina syndrome, presenting as a result of spinal infection, such as the case reported here, is extremely rare but clinically important. Surgical intervention is generally the recommended therapeutic modality.     

Covid-19 in liver transplant recipients: the French SOT COVID registry

BackgroundNotwithstanding the ongoing coronavirus disease-2019 (Covid-19) pandemic, information on its clinical presentation and prognosis in organ transplant recipients remains limited. The aim of this registry-based observational study was to report the characteristics and clinical outcomes of liver transplant (LT) recipients included in the French nationwide Registry of Solid Organ Transplant Recipients with Covid-19.MethodsCOVID-19 was diagnosed in patients who had a positive PCR assay for SARS-CoV-2 or in presence of typical lung lesions on imaging or specific SARS-CoV-2 antibodies. Clinical and laboratory characteristics, management of immunosuppression, treatment for Covid-19, and clinical outcomes (hospitalization, admission to intensive care unit, mechanical ventilation, or death) were recorded.ResultsOf the 104 patients, 67 were admitted to hospital and 37 were managed at home (including all 13 children). Hospitalized patients had a median age of 65.2 years (IQR: 58.1 ? 73.2 years) and two thirds were men. Most common comorbidities included overweight (67.3%), hypertension (61.2%), diabetes (50.7%), cardiovascular disease (20.9%) and respiratory disease (16.4%). SARS-CoV-2 infection was identified after a median of 92.8 months (IQR: 40.1 ? 194.7 months) from LT. During hospitalization, antimetabolites, mTOR inhibitor, and CNIs were withdrawn in 41.9%, 30.0% and 12.5% of patients, respectively. The composite endpoint of severe Covid-19 within 30 days after diagnosis was reached by 33.0% of the adult patients. The 30-day mortality rate was 20.0%, and 28.1% for hospitalized patients. Multivariate analysis identified that age was independently associated with mortality.ConclusionIn our large nationwide study, Covid-19 in LT recipients was associated with a high mortality rate.     

Functional regulatory immune responses against human cartilage glycoprotein-39 in health vs. proinflammatory responses in rheumatoid arthritis

The class of immune response against autoantigens could profoundly influence the onset and/or outcome of autoimmune diseases. Until now, there is only limited information on the antigen-specific balance between proinflammatory and regulatory responses in humans. Here we analyzed the natural immune response against a candidate autoantigen in rheumatoid arthritis, human cartilage glycoprotein-39 (HC gp-39). Peripheral blood mononuclear cells from healthy individuals reacted against HC gp-39 with the production of IL-10 but not IFN-gamma. Ex vivo assays indicated that the naturally occurring HC gp-39-specific immune response in bulk is powerful enough to suppress antigen-specific recall responses, demonstrating that rather than being unresponsive, the HC gp-39-directed immune response in healthy individuals shows a strong bias toward a regulatory phenotype. Moreover, CD4(+) T cell lines directed against HC gp-39 expressed CD25, glucocorticoid-induced tumor necrosis factor receptor, and Foxp3 molecules and were capable of suppressing antigen-specific T cell responses. Cell-cell contact was required for this suppression. As opposed to healthy individuals, the HC gp-39-directed immune response in 50% of patients with rheumatoid arthritis exhibits polarization toward a proinflammatory T helper 1 phenotype and is significantly less powerful in suppressing antigen-specific recall responses. Together these findings indicate that the presence of HC gp-39-specific immune responses in healthy individuals may have an inhibitory effect on inflammatory responses in areas where HC gp-39 is present. Furthermore, these data indicate that the class of HC gp-39-directed immune response in rheumatoid arthritis patients has shifted from an antiinflammatory toward a proinflammatory phenotype.