Idiopathic retroperitoneal haematoma causing duodenal obstruction: a case report and review of literature.

Idiopathic retroperitoneal haematoma is a rare clinical entity; resulting duodenal obstruction is even more occult. It can pose a diagnostic challenge due to variable presentations. Timely management requires a high index of suspicion and a multidisciplinary approach. Surgery is indicated in patients refractory to conservative treatment and failure of endoscopic or interventional radiology options. We report an interesting case illustrating the rarity and severity of this condition, with a review of the literature.

Cytosolic phospholipase A2 regulates alcohol-mediated astrocyte inflammatory responses in HIV-associated neurocognitive disorders.

Alcohol (EtOH) abuse and HIV-1 infection remain leading public health problems not only in the United States but also across the world. Alcohol abusers have a significantly greater risk of HIV-1 infection than non-drinkers globally. In the United States, prevalence of EtOH abuse is over two-fold higher in HIV-1-positive individuals than that of the general population. Although alcohol abusers show neurodegeneration, exacerbated neuroinflammation and oxidative damage, the mechanism(s) by which EtOH regulates astrocyte inflammatory responses in HIV-associated neurocognitive disorders is unknown. Thus, we explored signaling pathway(s) involved in EtOH-mediated activation of human astrocytes with HIV-1 and subsequent alterations in their inflammatory functions. Alcohol exposure altered the morphology of astrocytes, proinflammatory responses and induced cytotoxicity in a dose-dependent manner. Time-dependent changes were also evaluated. EtOH and HIV-1 cotreatment decreased cell viability and proliferation, while increasing apoptosis and mitochondrial depolarization. EtOH and HIV-1 together increased the levels of proinflammatory molecules, interleukin-1ß, tumor necrosis factor-α, CXCL8, tissue inhibitor of metalloproteinases-1 and more importantly, arachidonic acid, a known downstream target of cytosolic phospholipase A2 (cPLA2). Consistent with this observation, phospho-cPLA2 levels were augmented in HIV-1 and EtOH cotreatment as compared with HIV-1 or EtOH alone. Cyclooxygenase 2 was upregulated as measured by real-time PCR and western blot, whereas cotreatment of HIV-1 and EtOH decreased cytochrome P450-2E1 levels as compared with EtOH alone. Furthermore, we confirmed that blocking cPLA2 with arachidonyl tri floro methyl ketone, a cPLA2-specific inhibitor, effectively prevented cPLA2 phosphorylation and downstream outcomes. Thus, the present findings suggest that cPLA2 has a critical role in alcohol and HIV-induced astrocyte inflammation. In the future, cPLA2 inhibitors may present novel therapeutic tools to treat alcohol abuse and HIV-associated neurocognitive disorder comorbidity.

Nanoparticle-mediated catalase delivery protects human neurons from oxidative stress.

Several neurodegenerative diseases and brain injury involve reactive oxygen species and implicate oxidative stress in disease mechanisms. Hydrogen peroxide (H2O2) formation due to mitochondrial superoxide leakage perpetuates oxidative stress in neuronal injury. Catalase, an H2O2-degrading enzyme, thus remains an important antioxidant therapy target. However, catalase therapy is restricted by its labile nature and inadequate delivery. Here, a nanotechnology approach was evaluated using catalase-loaded, poly(lactic co-glycolic acid) nanoparticles (NPs) in human neuronal protection against oxidative damage. This study showed highly efficient catalase encapsulation capable of retaining ~99% enzymatic activity. NPs released catalase rapidly, and antioxidant activity was sustained for over a month. NP uptake in human neurons was rapid and nontoxic. Although human neurons were highly sensitive to H2O2, NP-mediated catalase delivery successfully protected cultured neurons from H2O2-induced oxidative stress. Catalase-loaded NPs significantly reduced H2O2-induced protein oxidation, DNA damage, mitochondrial membrane transition pore opening and loss of cell membrane integrity and restored neuronal morphology, neurite network and microtubule-associated protein-2 levels. Further, catalase-loaded NPs improved neuronal recovery from H2O2 pre-exposure better than free catalase, suggesting possible applications in ameliorating stroke-relevant oxidative stress. Brain targeting of catalase-loaded NPs may find wide therapeutic applications for oxidative stress-associated acute and chronic neurodegenerative disorders.

Tissue inhibitor of metalloproteinases-1 protects human neurons from staurosporine and HIV-1-induced apoptosis: mechanisms and relevance to HIV-1-associated dementia.

HIV-1-associated dementia (HAD)-relevant proinflammatory cytokines robustly induce astrocyte tissue inhibitor of metalloproteinases-1 (TIMP-1). As TIMP-1 displays pleotropic functions, we hypothesized that TIMP-1 expression may serve as a neuroprotective response of astrocytes. Previously, we reported that chronically activated astrocytes fail to maintain elevated TIMP-1 expression, and TIMP-1 levels are lower in the brain of HAD patients; a phenomenon that may contribute to central nervous system pathogenesis. Further, the role of TIMP-1 as a neurotrophic factor is incompletely understood. In this study, we report that staurosporine (STS) and HIV-1(ADA) virus, both led to induction of apoptosis in cultured primary human neurons. Interestingly, cotreatment with TIMP-1 protects neurons from apoptosis and reverses neuronal morphological changes induced by these toxins. Further, the anti-apoptotic effect was not observed with TIMP-2 or -3, but was retained in a mutant of the N-terminal TIMP-1 protein with threonine-2 mutated to glycine (T2G) that is deficient in matrix metalloproteinase (MMP)-1, -2 and -3 inhibitory activity. Therefore, the mechanism is specific to TIMP-1 and partially independent of MMP-inhibition. Additionally, TIMP-1 modulates the Bcl-2 family of proteins and inhibits opening of mitochondrial permeability transition pores induced by HIV-1 or STS. Together, these findings describe a novel function, mechanism and direct role of TIMP-1 in neuroprotection, suggesting its therapeutic potential in HAD and possibly in other neurodegenerative diseases.

Production and Roles of Glial Tissue Inhibitor of Metalloproteinases-1 in Human Immunodeficiency Virus-1-Associated Dementia Neuroinflammation: A Review.

PROBLEM STATEMENT: Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) and its cognate targets, the Matrix Metalloproteinases (MMPs), were differentially expressed in human brain samples with or without HIV-1 infection or HIV-1 Encephalitis (HIVE). APPROACH: A through literature review demonstrated that cell culture models of Central Nervous System (CNS) cell types had been used to illustrate the intricate temporal patterns of TIMP-1/MMP expression, regulated by a variety of inflammatory cytokines. RESULTS: As MMPs and TIMP-1 can significantly altered the extracellular environment and cell signaling, the differential regulation of TIMP-1/MMP expression in neuroinflammation can impact neuronal function and survival in disease conditions. TIMP-1 pro-survival effects had been demonstrated in a variety of cell types including CNS neurons, protecting cells from a wide range of stress and insults. TIMP-1, also known to interact with non-MMP targets, altered cell behavior. In this review, we discussed the possibility that the upregulation of TIMP-1 by glia in acute neuroinflammation may be a neuroprotective response. CONCLUSION: It will be important to delineate the effects of TIMP-1 on neurons and identify receptors and downstream signaling pathways, in order to evaluate TIMP-1 as a therapeutic strategy for neuroinflammatory and neurodegenerative diseases.

Polymorphic ecthymatoid dermosporidiosis.

We report the case of a young Chhattisgarhi male with polymorphic dermosporidiosis (cutaneous rhinosporidiosis). He had multiple subcutaneous nodules and an ecthymatoid skin lesion along with nasal rhinosporidiosis. The diagnosis was confirmed by demonstration of sporangia with endospores in fine-needle aspiration cytology (FNAC), histopathology, and imprint smear from the skin lesions. Treatment was by surgical excision, electrocoagulation, and dapsone. There was no recurrence. Dermatologists should be aware of the diverse cutaneous manifestations of this primarily nasal disease. This is the second published report of polymorphic dermosporidiosis, and the first one reporting an ecthymatoid lesion.

Acquired Blaschkoid dermatitis.

Acquired Blaschkoid dermatitis characterised by unilateral relapsing inflammatory disease along the lines of Blaschko. A 40-year-old Indian male presented with unilateral erythematous, itchy grouped papules on the left side of the chest, abdomen, back and left arm of 15 days duration. The eruption stopped abruptly at the midline of the torso, completely sparing the right side of the body. The lesions were arranged in whorls and streaks corresponding to the lines of Blaschko. Skin biopsy showed hyperkeratosis and features suggestive of sub-acute spongiotic dermatitis with lymphocytic infiltrate around the blood vessels in the dermis. Patient was diagnosed as a case of Blaschkoid dermatitis. To the best of our knowledge, this is the first case of this condition being reported from India.

Giant cutaneous rhinosporidiosis.

A young male with a single, huge subcutaneous lesion of rhinosporidiosis is reported. The diagnosis was suggested by the presence of nasal rhinosporidiosis and confirmed by fine-needle aspiration cytology (FNAC) from the skin lesion. This is the second report of giant skin lesions in rhinosporidiosis, from our department.

Alcohol-induced oxidative stress in brain endothelial cells causes blood-brain barrier dysfunction.

Brain microvascular endothelial cells (BMVEC) connected by tight junctions (TJ) form a tight monolayer at the blood-brain barrier (BBB). We investigated the idea that BBB dysfunction seen in alcohol abuse is associated with oxidative stress stemming from ethanol (EtOH) metabolism in BMVEC. Exposure to EtOH induced catalytic activity/expression of EtOH-metabolizing enzymes, which paralleled enhanced generation of reactive oxygen species (ROS). EtOH-mediated oxidative stress led to activation of myosin light chain (MLC) kinase, phosphorylation of MLC and TJ proteins, decreased BBB integrity, and enhanced monocyte migration across BBB. Acetaldehyde or ROS donors mimicked changes induced by EtOH in BMVEC. Thus, oxidative stress resulting from alcohol metabolism in BMVEC can lead to BBB breakdown in alcohol abuse, serving as an aggravating factor in neuroinflammatory disorders.