Comparative Study of Postmortem MRI and Pathological Findings in Malignant Brain Tumors.

This study compared magnetic resonance imaging (MRI) findings of postmortem brain specimens with neuropathological findings to evaluate the value of postmortem MRI. Postmortem MRI was performed on five formalin-fixed whole brains with malignant tumors. Postmortem T2-weighted images detected all neuropathological abnormalities as high-signal regions but also showed histological tumor invasion in areas without edema. Tumor lesions with high necrosis and edema showed high signal intensity on T2-weighted images; in three cases, lesion enlargement was detected on the final prenatal imaging and postmortem MRI. Disease progression immediately before death may have contributed to this difference. In conclusion, the correlation between MRI and neuropathological findings facilitates understanding of the mechanisms responsible for MRI abnormalities. Increased free water due to edema, necrosis, and brain tissue injury can explain the increased signal intensity observed on T2-weighted images. Postmortem MRI may contribute to effective pathology by identifying subtle abnormalities prior to brain dissection.

Evaluation of Treatment Strategies for Male Prolactin-Secreting Pituitary Neuroendocrine Tumors.

Prolactin-secreting pituitary neuroendocrine tumors (PitNETs) are more common in women. Male patients may also have few symptoms and have macroadenomas extending outside the sella turcica. This study aimed to report the results of cabergoline treatment in male patients with prolactin-secreting PitNET. The study included nine male patients aged 26-65 years (median, 46 years) diagnosed with prolactin-secreting PitNETs. The age at onset, prolactin values, tumor size, symptoms, and treatment were assessed. The mean prolactin value at the initial presentation was 2734.6 ng/mL, and the mean maximum tumor diameter was 40.4 mm. Visual field disturbance was the most common symptom (44.4%), followed by headaches (33.3%), asymptomatic symptoms (11.1%), and galactorrhea (11.1%). Eight patients responded to cabergoline treatment with normalization of prolactin levels and tumor shrinkage. One patient did not respond to the cabergoline treatment and required surgical intervention. There were no cases of cerebrospinal fluid leakage. Cabergoline was found to be an effective treatment for male prolactin-secreting PitNETs.

MIND bomb 2 prevents RIPK1 kinase activity-dependent and -independent apoptosis through ubiquitylation of cFLIPL.

Mind bomb 2 (MIB2) is an E3 ligase involved in Notch signalling and attenuates TNF-induced apoptosis through ubiquitylation of receptor-interacting protein kinase 1 (RIPK1) and cylindromatosis. Here we show that MIB2 bound and conjugated K48- and K63-linked polyubiquitin chains to a long-form of cellular FLICE-inhibitory protein (cFLIPL), a catalytically inactive homologue of caspase 8. Deletion of MIB2 did not impair the TNF-induced complex I formation that mediates NF-κB activation but significantly enhanced formation of cytosolic death-inducing signalling complex II. TNF-induced RIPK1 Ser166 phosphorylation, a hallmark of RIPK1 death-inducing activity, was enhanced in MIB2 knockout cells, as was RIPK1 kinase activity-dependent and -independent apoptosis. Moreover, RIPK1 kinase activity-independent apoptosis was induced in cells expressing cFLIPL mutants lacking MIB2-dependent ubiquitylation. Together, these results suggest that MIB2 suppresses both RIPK1 kinase activity-dependent and -independent apoptosis, through suppression of RIPK1 kinase activity and ubiquitylation of cFLIPL, respectively.