Mllt11 Regulates Migration and Neurite Outgrowth of Cortical Projection Neurons during Development.

The formation of connections within the mammalian neocortex is highly regulated by both extracellular guidance mechanisms and intrinsic gene expression programs. There are two types of cortical projection neurons (CPNs): those that project locally and interhemispherically and those that project to subcerebral structures such as the thalamus, hindbrain, and spinal cord. The regulation of cortical projection morphologies is not yet fully understood at the molecular level. Here, we report a role for Mllt11 (Myeloid/lymphoid or mixed-lineage leukemia; translocated to chromosome 11/All1 Fused Gene From Chromosome 1q) in the migration and neurite outgrowth of callosal projection neurons during mouse brain formation. We show that Mllt11 expression is exclusive to developing neurons and is enriched in the developing cortical plate (CP) during the formation of the superficial cortical layers. In cultured primary cortical neurons, Mllt11 is detected in varicosities and growth cones as well as the soma. Using conditional loss-of-function and gain-of-function analysis we show that Mllt11 is required for neuritogenesis and proper migration of upper layer CPNs. Loss of Mllt11 in the superficial cortex of male and female neonates leads to a severe reduction in fibers crossing the corpus callosum (CC), a progressive loss in the maintenance of upper layer projection neuron gene expression, and reduced complexity of dendritic arborization. Proteomic analysis revealed that Mllt11 associates with stabilized microtubules, and Mllt11 loss affected microtubule staining in callosal axons. Taken together, our findings support a role for Mllt11 in promoting the formation of mature upper-layer neuron morphologies and connectivity in the cerebral cortex.SIGNIFICANCE STATEMENT The regulation of cortical projection neuron (CPN) morphologies is an area of active investigation since the time of Cajal. Yet the molecular mechanisms of how the complex dendritic and axonal morphologies of projection neurons are formed remains incompletely understood. Although conditional mutagenesis analysis in the mouse, coupled with overexpression assays in the developing fetal brain, we show that a novel protein called Mllt11 is sufficient and necessary to regulate the dendritic and axonal characteristics of callosal projection neurons in the developing mammalian neocortex. Furthermore, we show that Mllt11 interacts with microtubules, likely accounting for its role in neuritogenesis.

Development of the mammalian cortical hem and its derivatives: the choroid plexus, Cajal-Retzius cells and hippocampus.

The dorsal medial region of the developing mammalian telencephalon plays a central role in the patterning of the adjacent brain regions. This review describes the development of this specialized region of the vertebrate brain, called the cortical hem, and the formation of the various cells and structures it gives rise to, including the choroid plexus, Cajal-Retzius cells and the hippocampus. We highlight the ontogenic processes that create these different forebrain derivatives from their shared embryonic origin and discuss the key signalling pathways and molecules that influence the patterning of the cortical hem. These include BMP, Wnt, FGF and Shh signalling pathways acting with Homeobox factors to carve the medial telencephalon into district progenitor regions, which in turn give rise to the choroid plexus, dentate gyrus and hippocampus. We then link the formation of the lateral ventricle choroid plexus with embryonic and postnatal neurogenesis in the hippocampus.

NUT Carcinoma in a Patient with Unusually Long Survival and False Negative FISH Results.

Nuclear protein in testis (NUT) carcinoma is a rare and highly aggressive epithelial malignancy defined by rearrangement of the NUTM1 gene on chromosome 15q14. Histologically, NUT carcinoma is an undifferentiated carcinoma formed by sheets and nests of primitive and monotonous "round blue cells" with foci of abrupt keratinization in a subset. NUT carcinoma runs a fulminant clinical course and is almost always quickly lethal, with a median overall survival of only 6.7 months. There is no consensus regarding treatment for this disease, and most patients respond poorly to conventional chemotherapy and radiation. We report a case of NUT carcinoma in an African-American man who initially presented in 2009 with a tracheal mass at age 28. Although fluorescence in situ hybridization (FISH) assays for NUTM1 and BRD4 rearrangements were negative, he was diagnosed based on diffusely positive NUT immunostaining and BRD4-NUTM1 on RNA sequencing. Since his initial presentation, he has undergone multiple surgical procedures and radiation therapy. His tumor has recurred twice, but he has survived for 129 months and is currently alive without disease. Long-term survival of patients with NUT carcinoma is incredibly unusual, especially in patients with tumors that exhibit a BRD4 rearrangement. False negative FISH is a pitfall in diagnosing NUT carcinoma; NUT immunostaining and RNA sequencing are more sensitive diagnostic methods.

Upregulation of Endothelial HLA Class II is a Marker of Antibody-Mediated Rejection in Heart Allograft Biopsies.

In 2013, the International Society of Heart and Lung Transplant (ISHLT) introduced the working classification for pathologic changes associated with antibody-mediated rejection (AMR) of the heart allograft, known as pathologic AMR (pAMR). With 2 components associated with AMR, histopathologic changes) and immunopathologic markers, the proposed classification also suggests the use of class II HLA as a marker of endothelial integrity. It is known that during allograft rejection, endothelial cells are activated, therefore, we hypothesized that endothelial class II HLA rather than a marker of mere endothelial presence, is a marker of endothelial activation and becomes upregulated in AMR. Eight hundred thirty-eight heart allograft biopsies, collected from January 2016 to September 2018 at a single institution from patients with a current or recent diagnosis of AMR, were evaluated for both histopathologic and immunopathologic changes of AMR. Biopsies were labeled with immunofluorescence with antibodies against C4d and for immunohistochemistry with antibodies against C3d, CD68, and class II HLA. ISHLT criteria were used to classify the biopsies, and for class II HLA, both the percentage and the stain intensity were evaluated. Biopsies (74.8%) from our cohort showed either histopathologic pAMR-1, immunopathologic pAMR-1, or combined histopathologic and immunopathologic pAMR-2 evidence of AMR. Expression of endothelial HLA class II was significantly correlated with the diagnosis of AMR by percentage area (P < .0001) and intensity of staining (P < .0001). The diagnosis of AMR significantly correlated with moderate (+2) and strong (+3) staining intensity for class II HLA as follows: histopathologic and immunopathologic pAMR-2 with odds ratio (OR) = 28.3 (P < .0001);histopathologic pAMR-1 alone with OR = 22.7 (P < .0001); and immunopathologic pAMR-1 alone with OR = 32.6 (P < .0001). Interestingly, our study also suggested that the inclusion of C4d focally positive cases also significantly correlates with the diagnosis of AMR (P < .003). We confirmed our hypothesis that in heart allograft biopsies, there is a spectrum of both percentage and intensity of HLA class II expression due to endothelial activation, and that class II HLA by immunohistochemistry is a marker significantly correlated with the diagnosis of AMR. In addition, the group of focally positive C4d biopsies (10%-50%) should be considered positive for the immunopathologic component of the 2013 ISHLT classification, as this group of biopsies also correlated with the diagnosis of AMR.

Mammary Paget's Disease of the Male Breast: A Rare Case With an Unusual Immunohistochemical Profile.

Mammary Paget's disease is rare and comprises about 0.62% of all breast cancer cases, only 1.65% of which occur in male patients. This case report involves a 76-year-old man who presented to his primary care physician with an itching, scaly, unilateral lesion involving the nipple skin. He underwent wide local excision of the lesion for a diagnosis of Bowen's disease (squamous cell carcinoma in situ). Histologic examination of the specimen revealed mammary Paget's disease with ductal carcinoma in situ in the underlying breast tissue. A panel of immunohistochemical stains revealed the Paget cells to be positive for cytokeratin 7, MUC1, GATA3, and androgen receptor and negative for cytokeratins 5/6, p63, SOX10, and MART-1/Melan-A. Paget cells were also negative for estrogen receptor and progesterone receptor, and positive for HER2/neu. However, the underlying ductal carcinoma in situ was positive for both estrogen receptor and progesterone receptor and negative for HER2/neu. This discordance, supported by the current literature, suggests an alternative etiology for Paget's disease in certain cases that cannot be explained by the well-established epidermotropic and transformative theories of Paget's disease evolution.

Diagnosis-Related Group in Colon Surgery: Identifying Areas of Improvement to Drive High-Value Care.

Diagnosis-related group (DRG) migration is defined as the reassignment of colectomy patients from DRG 331 to 330 based exclusively on postoperative complications. Strategic and comparative application of this metric has the potential to demonstrate baseline and excessive rates of complications related directly to patient care differences across institutions. The aim of this study was to report the variability of DRG migration across United States hospitals and its impact on overall cost and length of stay (LOS). This study investigated the variability of DRG migration rates across United States hospitals polling 5 per cent of the national Medicare data. The study endpoints were total cost, LOS, and DRG migration rate. Hospitals were classified into tertiles for low (0.1-16.6%), moderate (16.7-23.0%), and high (23.1-83.3%) DRG migration rates. The study included 5120 patients from 615 hospitals. DRG migration rates for hospitals ranged from 0.1 per cent to 83.3 per cent, with 157 in the low, 183 in the moderate, and 364 in the high tertile. DRG migration resulted in a progressively increased LOS and hospital costs from the lowest to highest tertile. Several diagnoses were identified which are suggestive of failure to integrate evidence-based processes of care across the tertiles. The data confirm a wide variation in DRG migration rates from DRG 331 to 330 based only on postoperative complications. These ranges allow for the potential definition of both best practice, and opportunities for quality improvement with respect to postoperative complications, identification of hospital outliers, and the economics of care as part of a value-based care program.

Three-year Results of a Pilot Program in Early Liver Transplantation for Severe Alcoholic Hepatitis.

OBJECTIVE: To examine our pilot to transplant selected patients with acute alcoholic hepatitis, initiated in October 2012. BACKGROUND: Six months of alcohol abstinence is typically required before liver transplant. A Franco-Belgian protocol showed that early transplant in severe alcoholic hepatitis could improve survival with low incidence of alcohol relapse. Application of this controversial indication is growing despite unclear generalizability. METHODS: Data was collected on all patients with alcohol-related liver disease since initiation of the pilot through June 2015. Patients were stratified into two groups: severe alcoholic hepatitis as first liver decompensation (Group 1), alcoholic cirrhosis with ≥6 months abstinence (Group 2). Alcohol relapse was defined as any evidence of alcohol consumption after transplant, which was assessed for harmful patterns of binge or frequent drinking. RESULTS: Forty-three patients underwent liver transplant, including 17 patients in Group 1. Six-month survival was 100% versus 89% for Groups 1 and 2, respectively (P = 0.27). Alcohol relapse was similar in Group 1 versus Group 2: 23.5% versus 29.2% (P > 0.99). Harmful drinking was higher in Group 1 versus Group 2, despite lack of statistical significance: 23.5% versus 11.5% (P = 0.42). CONCLUSIONS: In this pilot with carefully selected patients, early liver transplant provided excellent short-term survival, and similar rates of alcohol relapse compared with patients with 6 months of abstinence. Harmful patterns of relapse remain challenging in this population, highlighting the need for validated models to predict alcohol relapse, and need for extreme caution in selecting patients for this exceptional indication. Larger prospective studies and longer follow up are necessary.

The Prediction Predicament: Rethinking Necrotizing Soft Tissue Infections Mortality.

BACKGROUND: Our study sought to identify independent risk factors predisposing patients with necrotizing soft tissue infections (NSTIs) to mortality from among laboratory values, demographic data, and microbiologic findings in a small population. To this end, a retrospective review was conducted of the medical records of all patients with NSTI who had been treated at our institution from 2003 to 2012 (n=134). METHODS: Baseline demographics and comorbidities, clinical and laboratory values, hospital course, and the microbiologic characteristics of surgical incision cultures were recorded. Each variable was tested for association with survival status and all associated variables with p<0.15 were included in a logistic regression model to seek factors associated independently with mortality. RESULTS: Surprisingly, no demographic or pre-existing condition proved to be a predictor of mortality. Two laboratory values had an inverse correlation to mortality: High C-reactive protein (CRP) and highest recorded CRP. Of surgical incisions that grew bacteria in culture, 33.6% were polymicrobial. Mortality rates were highest with Enterococcus-containing polymicrobial infections (50%), followed by those containing Pseudomonas (40%), and Streptococcus spp. (27%). Understanding why so many studies across the literature, now including our own, find such disparate results for correlation of NSTI mortality with patient data may lie in the fundamentally dynamic nature of the organisms involved. CONCLUSIONS: This study suggests that no single factor present on admission is a robust predictor of outcome; it is likely that survival in NSTI is predicated upon a complex interaction of multiple host and microbial factors that do not lend themselves to reduction into a simple formula. It is also abundantly clear that the well-established principles of NSTI surgery should continue to be followed in all cases, with an emphasis on early debridement, irrespective of apparent severity of initial presentation.