Teaching NeuroImage: Neuroimaging Features of Wilson Disease.

A 13-year-old boy of nonconsanguineous parents presented with abnormal body movements, gait difficulty, and slurring of speech for 2 years. On examination, he had rigidity, dystonia, dysarthria, and drooling. Ophthalmologic examination revealed bilateral Kayser-Fleischer rings. He had elevated serum "free" copper levels (41.2 µg/dL [range:10-15]), 24-hour urine copper levels (895.7 µg/d [range:<60]), and reduced serum ceruloplasmin levels (4.3 mg/dL (range:20-40]). MRI revealed "face of giant panda" appearance (Figure A), T2-fluid attenuated inversion recovery hyperintensities (Figure, B and C), and frontal cystic encephalomalacic changes (Figure D), suggestive of Wilson disease (WD). Face of giant panda in WD, first described by Hitoshi et al.,1 is due to high signal intensity in tegmentum with normal signals in red nuclei forming the eyes, normal signals of pars reticulata (lateral portion) of substantia nigra forming the ears, and hypointensity of superior colliculus forming the chin.2 Bilateral cystic changes are less commonly reported in WD.3 Recognizing diverse neuroimaging signatures beyond well-known findings in WD enhances diagnostic accuracy.

Primary Diffuse Leptomeningeal Melanomatosis in an Indian Child With Review of Literature.

BACKGROUND: Primary diffuse leptomeningeal melanomatosis (PDLM) is an extremely rare, aggressive malignant neoplasia of the central nervous system. We report the first case of pediatric PDLM from India. METHODS: A review of literature was done to describe the 15 pediatric cases reported so far. RESULTS: A 12-year-old male child presented with fever, vomiting, and headache for 2 months. Cerebrospinal fluid examination was normal. An MRI of the brain revealed hydrocephalus, for which antitubercular therapy was started and external ventricular drainage followed by ventriculoperitoneal shunt was done. Repeat MRI revealed a suprasellar lesion, nodular enhancement of cranial nerves along with dural enhancement of spinal cord with arachnoiditis, and long-segment myelomalacia. Repeat cerebrospinal fluid examination was negative for malignant cells. During biopsy, blackish dura with diffuse blackish deposits in ventricle were noted. Histopathological examination revealed tumor cells with intracytoplasmic coarse brown pigment melanoma, frequent mitotic figures, and immunohistochemistry testing was positive for human melanoma black-45 and MelanA, suggestive of PDLM. He expired 4 months after the diagnosis. CONCLUSION: Diagnosing PDLM can be daunting in light of its slow but malignant progression mimicking TBM leading to improper management. However, the absence of any supportive microbiological evidence and failure to respond to the standard antitubercular therapy with subsequent progression of the symptoms should prompt the need for finding an alternative diagnosis. A targeted molecular diagnosis and precision medicine may provide a favorable outcome in children with PDLM.

Recent Advances in Targeting the Urokinase Plasminogen Activator with Nanotherapeutics.

The aberrant proteolytic landscape of the tumor microenvironment is a key contributor of cancer progression. Overexpression of urokinase plasminogen activator (uPA) and/or its associated cell-surface receptor (uPAR) in tumor versus normal tissue is significantly associated with worse clinicopathological features and poorer patient survival across multiple cancer types. This is linked to mechanisms that facilitate tumor cell invasion and migration, via direct and downstream activation of various proteolytic processes that degrade the extracellular matrix─ultimately leading to metastasis. Targeting uPA has thus long been considered an attractive anticancer strategy. However, poor bioavailability of several uPA-selective small-molecule inhibitors has limited early clinical progress. Nanodelivery systems have emerged as an exciting method to enhance the pharmacokinetic (PK) profile of existing chemotherapeutics, allowing increased circulation time, improved bioavailability, and targeted delivery to tumor tissue. Combining uPA inhibitors with nanoparticle-based delivery systems thus offers a remarkable opportunity to overcome existing PK challenges associated with conventional uPA inhibitors, while leveraging potent candidates into novel targeted nanotherapeutics for an improved anticancer response in uPA positive tumors.

The Urokinase Plasminogen Activation System in Pancreatic Cancer: Prospective Diagnostic and Therapeutic Targets.

Pancreatic cancer is a highly aggressive malignancy that features high recurrence rates and the poorest prognosis of all solid cancers. The urokinase plasminogen activation system (uPAS) is strongly implicated in the pathophysiology and clinical outcomes of patients with pancreatic ductal adenocarcinoma (PDAC), which accounts for more than 90% of all pancreatic cancers. Overexpression of the urokinase-type plasminogen activator (uPA) or its cell surface receptor uPAR is a key step in the acquisition of a metastatic phenotype via multiple mechanisms, including the increased activation of cell surface localised plasminogen which generates the serine protease plasmin. This triggers multiple downstream processes that promote tumour cell migration and invasion. Increasing clinical evidence shows that the overexpression of uPA, uPAR, or of both is strongly associated with worse clinicopathological features and poor prognosis in PDAC patients. This review provides an overview of the current understanding of the uPAS in the pathogenesis and progression of pancreatic cancer, with a focus on PDAC, and summarises the substantial body of evidence that supports the role of uPAS components, including plasminogen receptors, in this disease. The review further outlines the clinical utility of uPAS components as prospective diagnostic and prognostic biomarkers for PDAC, as well as a rationale for the development of novel uPAS-targeted therapeutics.

Screening of 5- and 6-Substituted Amiloride Libraries Identifies Dual-uPA/NHE1 Active and Single Target-Selective Inhibitors.

The K+-sparing diuretic amiloride shows off-target anti-cancer effects in multiple rodent models. These effects arise from the inhibition of two distinct cancer targets: the trypsin-like serine protease urokinase-type plasminogen activator (uPA), a cell-surface mediator of matrix degradation and tumor cell invasiveness, and the sodium-hydrogen exchanger isoform-1 (NHE1), a central regulator of transmembrane pH that supports carcinogenic progression. In this study, we co-screened our library of 5- and 6-substituted amilorides against these two targets, aiming to identify single-target selective and dual-targeting inhibitors for use as complementary pharmacological probes. Closely related analogs substituted at the 6-position with pyrimidines were identified as dual-targeting (pyrimidine 24 uPA IC50 = 175 nM, NHE1 IC50 = 266 nM, uPA selectivity ratio = 1.5) and uPA-selective (methoxypyrimidine 26 uPA IC50 = 86 nM, NHE1 IC50 = 12,290 nM, uPA selectivity ratio = 143) inhibitors, while high NHE1 potency and selectivity was seen with 5-morpholino (29 NHE1 IC50 = 129 nM, uPA IC50 = 10,949 nM; NHE1 selectivity ratio = 85) and 5-(1,4-oxazepine) (30 NHE1 IC50 = 85 nM, uPA IC50 = 5715 nM; NHE1 selectivity ratio = 67) analogs. Together, these amilorides comprise a new toolkit of chemotype-matched, non-cytotoxic probes for dissecting the pharmacological effects of selective uPA and NHE1 inhibition versus dual-uPA/NHE1 inhibition.