Sustained Trem2 stabilization accelerates microglia heterogeneity and Aβ pathology in a mouse model of Alzheimer's disease.

TREM2 is a transmembrane protein expressed exclusively in microglia in the brain that regulates inflammatory responses to pathological conditions. Proteolytic cleavage of membrane TREM2 affects microglial function and is associated with Alzheimer's disease, but the consequence of reduced TREM2 proteolytic cleavage has not been determined. Here, we generate a transgenic mouse model of reduced Trem2 shedding (Trem2-Ile-Pro-Asp [IPD]) through amino-acid substitution of an ADAM-protease recognition site.

A transcribed enhancer dictates mesendoderm specification in pluripotency.

Enhancers and long noncoding RNAs (lncRNAs) are key determinants of lineage specification during development. Here, we evaluate remodeling of the enhancer landscape and modulation of the lncRNA transcriptome during mesendoderm specification. We sort mesendodermal progenitors from differentiating embryonic stem cells (ESCs) according to Eomes expression, and find that enhancer usage is coordinated with mesendoderm-specific expression of key lineage-determining transcription factors.

Esophageal carcinoma with prominent spindle cells.

Eight cases of esophageal carcinoma with prominent spindle cells (carcinosarcoma or pseudosarcoma) were studied using the avidin-biotin immunoperoxidase method and monoclonal antibodies to various keratins and vimentin. In all eight cases positive immunoreactivity for keratin was found in carcinomatous areas and for vimentin, in the spindle cells. It is interesting that five cases demonstrated focal immunoreactivity to keratin in the spindle cell component.

Suture technique in preventing dehiscence of prosthetic mitral valves.

To evaluate suture techniques for mitral valve replacement, 60 fresh porcine hearts were used to determine suture holding strength. Using four techniques (simple interrupted, figure-of-eight, and horizontal without and with pledgets), the anterior leaflet, the posterior leaflet, and the commissures were sutured. The free ends of the sutures were then attached to a force transducer, and tension was increased until disruption occurred.

Epithelioid leiomyosarcoma originating in a hamartomatous polyp from a patient with Peutz-Jeghers syndrome.

A case of Peutz-Jeghers syndrome with long history and multiple resections is presented. Despite the large number of intestinal polyps in these patients, malignant transformations are rare. In this case, an epithelioid leiomyosarcoma developed within a single polyp.