Middle cerebral artery infarction, A rare complication of intracranial cryptococcoma in an immunocompetent patient: A case report and literature review.

Background: This report presents the first case of intracranial cryptococcoma arising from the right frontal lobe causing right middle cerebral artery infarction. Intracranial cryptococcomas usually occur in the cerebral parenchyma, basal ganglia, cerebellum, pons, thalamus, and choroid plexus; they may mimic intracranial tumors, but seldom cause infarction. Of the 15 cases of pathology-confirmed intracranial cryptococcomas in the literature, no case has been complicated by middle cerebral artery (MCA) infarction. Here, we discuss a case of intracranial cryptococcoma with an ipsilateral middle cerebral artery infarction. Case Description: A 40-year-old man was referred to our emergency room due to progressive headaches and acute left hemiplegia. The patient was a construction worker with no history of avian contact, recent travel, or human immunodeficiency virus (HIV) infection. Brain computed tomography (CT) showed an intra-axial mass, and subsequent magnetic resonance imaging (MRI) delineated a large mass of 53 mm in the right middle frontal lobe and a small lesion of 18 mm in the right caudate head, with marginal enhancement and central necrosis. A neurosurgeon was consulted in view of the intracranial lesion, and the patient underwent en-bloc excision of the solid mass. The pathology report later identified a Cryptococcus infection rather than malignancy. The patient underwent 4 weeks of postoperative treatment with amphotericin B plus flucytosine; he then received subsequent oral antifungal treatment for 6 months, and had neurologic sequelae that manifested as left side hemiplegia. Conclusion: Diagnosis of fungal infections in the CNS remains challenging. This is especially true of Cryptococcus CNS infections that present as a space-occupying lesion in an immunocompetent patient. A Cryptococcus infection should be considered in the differential diagnoses in patients with brain mass lesions, as this infection can be misdiagnosed as a brain tumor.

Impact of Diabetic Hyperglycemia on Clinical Outcomes in Patients with Diabetes Mellitus Following Traumatic Brain Injury.

AIM: To identify the effect of patients with diabetes mellitus (DM) with traumatic brain injury (TBI) in Taiwan. MATERIAL AND METHODS: Data from the trauma registry in Chang Gung Memorial Hospital, Linkou, Taiwan were collected and reviewed. Several clinical characteristics and outcomes were extracted and analyzed. The trauma databank includes 3090 patient medical records, of which 475 patients were identified as having DM. Because several baseline characteristics of patients with TBI in the DM group differed from those in the non-DM group, we performed propensity score matching to eliminate confounding factors. RESULTS: After propensity score matching, 895 patients with TBI comprised the non-DM group, and no significant differences were noted in the baseline characteristics between groups. Patients in the DM group had more craniotomies, longer hospital stays, and longer ICU stays. We also segmented the DM group into two subgroups based on survival status. Compared with the survivor group, the nonsurvivor group had a significantly higher serum glucose level. Furthermore, patients with DM were divided into four subgroups according to their serum glucose level. The in-hospital mortality rate was higher in the subgroup with glucose levels greater than 200mg/dL than in the other subgroups. A receiver-operating-characteristic analysis revealed that the ability of serum glucose level to predict in-hospital mortality was modest, with an area under the curve of 0.641 and an associated optimal cutoff of 206 mg/dl. CONCLUSION: DM should be considered a risk factor for patients with TBI receiving neurosurgical intervention and a predictor of longer hospitalization and stay in an intensive care unit. Moreover, in patients with TBI with DM, higher admission serum glucose levels are associated with a higher in-hospital mortality rate.

From in Silico Discovery to intra-Cellular Activity: Targeting JNK-Protein Interactions with Small Molecules.

The JNK-JIP1 interaction represents an attractive target for the selective inhibition of JNK-mediated signaling. We report a virtual screening (VS) workflow, based on a combination of three-dimensional shape and electrostatic similarity to discover novel scaffolds for the development of non-ATP competitive inhibitors of JNK targeting the JNK-JIP interaction. Of 352 (0.13%) compounds selected from the NCI diversity set more than 22% registered as hits in a biochemical kinase assay. Several compounds discovered to inhibit JNK activity under standard kinase assay conditions also impeded JNK activity in HEK293 cells. These studies led to the discovery that the lignan (-)-zuonin A inhibits JNK-protein interactions with a selectivity of 100-fold over ERK2 and p38 MAPKα. These results demonstrate the utility of a virtual screening protocol to identify novel scaffolds for highly selective, cell-permeable inhibitors of JNK-protein interactions.

Manipulating JNK signaling with (--)-zuonin A.

Recently, in a virtual screening strategy to identify new compounds targeting the D-recruitment site (DRS) of the c-Jun N-terminal kinases (JNKs), we identified the natural product (-)-zuonin A. Here we report the asymmetric synthesis of (-)-zuonin A and its enantiomer (+)-zuonin A. A kinetic analysis for the inhibition of c-Jun phosphorylation by (-)-zuonin A revealed a mechanism of partial competitive inhibition. Its binding is proposed to weaken the interaction of c-Jun to JNK by approximately 5-fold, without affecting the efficiency of phosphorylation within the complex. (-)-Zuonin A inhibits the ability of both MKK4 and MKK7 to phosphorylate and activate JNK. The binding site of (-)-zuonin A is predicted by docking and molecular dynamics simulation to be located in the DRS of JNK. (+)-Zuonin A also binds JNK but barely impedes the binding of c-Jun. (-)-Zuonin A inhibits the activation of JNK, as well as the phosphorylation of c-Jun in anisomycin-treated HEK293 cells, with the inhibition of JNK activation being more pronounced. (-)-Zuonin A also inhibits events associated with constitutive JNK2 activity, including c-Jun phosphorylation, basal Akt activation, and MDA-MB-231 cell migration. Mutations in the predicted binding site for (-)-zuonin A can render it significantly more or less sensitive to inhibition than wild type JNK2, allowing for the design of potential chemical genetic experiments. These studies suggest that the biological activity reported for other lignans, such as saucerneol F and zuonin B, may be the result of their ability to impede protein-protein interactions within MAPK cascades.