Effect of Specimen Extraction Site on Postoperative Incisional Hernia After Minimally Invasive Right Colectomy.

BACKGROUND: Incisional hernia (IH) is a known complication after colorectal surgery. Despite advances in minimally invasive surgery, colorectal surgery still requires extraction sites for specimen retrieval, increasing the likelihood of postoperative IH development.The objective of this study is to determine the effect of specimen extraction site on the rate of IH after minimally invasive right-sided colectomy for patients with available imaging. STUDY DESIGN: This is a retrospective multi-institutional cohort study at 2 large academic medical centers in the US. Adults who underwent right-sided minimally invasive colectomy from 2012-2020 with abdominal imaging available at least 1 year postoperatively were included in the analysis. The primary exposure was specimen extraction via a midline specimen extraction vs Pfannenstiel specimen extraction. The main outcome was the development of IH at least 1 year postoperatively as visualized on CT scan. RESULTS: Of the 341 patients sampled, 194 (57%) had midline specimen extraction and 147 (43%) had a Pfannenstiel specimen extraction. Midline extraction patients were older (66 ± 15 vs 58 ± 16; P<0.001) and had a higher rate of previous abdominal operation (99, 51% vs 55, 37%, P=0.01). The rate of IH was higher in midline extraction at 25% (n=48) compared with Pfannenstiel extraction (n=0, 0%) (P<0.001). The average length of stay was higher in the midline extraction group at 5.1±2.5 compared with 3.4±3.1 days in the Pfannenstiel extraction group (P<0.001). Midline extraction was associated with IH development (OR: 24.6; 95% CI 1.89-319.44; p=0.004). Extracorporeal anastomosis was associated with a higher IH rate (OR: 25.8; 95% CI 2.10-325.71; P=0.002). CONCLUSION: Patients who undergo Pfannenstiel specimen extraction have a lower risk of IH development compared with those who undergo midline specimen extraction.

BET protein Brd4 activates transcription in neurons and BET inhibitor Jq1 blocks memory in mice.

Precise regulation of transcription is crucial for the cellular mechanisms underlying memory formation. However, the link between neuronal stimulation and the proteins that directly interact with histone modifications to activate transcription in neurons remains unclear. Brd4 is a member of the bromodomain and extra-terminal domain (BET) protein family, which binds acetylated histones and is a critical regulator of transcription in many cell types, including transcription in response to external cues. Small molecule BET inhibitors are in clinical trials, yet almost nothing is known about Brd4 function in the brain. Here we show that Brd4 mediates the transcriptional regulation underlying learning and memory. The loss of Brd4 function affects critical synaptic proteins, which results in memory deficits in mice but also decreases seizure susceptibility. Thus Brd4 provides a critical link between neuronal activation and the transcriptional responses that occur during memory formation.

Dendritic cells loaded with FK506 kill T cells in an antigen-specific manner and prevent autoimmunity in vivo.

FK506 (Tacrolimus) is a potent inhibitor of calcineurin that blocks IL2 production and is widely used to prevent transplant rejection and treat autoimmunity. FK506 treatment of dendritic cells (FKDC) limits their capacity to stimulate T cell responses. FK506 does not prevent DC survival, maturation, or costimulatory molecule expression, suggesting that the limited capacity of FKDC to stimulate T cells may be due to inhibition of calcineurin signaling in the DC. Instead, we demonstrate that DC inhibit T cells by sequestering FK506 and continuously releasing the drug over several days. T cells encountering FKDC proliferate but fail to upregulate the survival factor bcl-xl and die, and IL2 restores both bcl-xl and survival. In mice, FKDC act in an antigen-specific manner to inhibit T-cell mediated autoimmune arthritis. This establishes that DCs can act as a cellular drug delivery system to target antigen specific T cells.DOI:http://dx.doi.org/10.7554/eLife.00105.001.

Flow cytometry analysis of immune cells within murine aortas.

Atherosclerosis is a chronic inflammatory process of medium and large size vessels that is characterized by the formation of plaques consisting of foam cells, immune cells, vascular endothelial and smooth muscle cells, platelets, extracellular matrix, and a lipid-rich core with extensive necrosis and fibrosis of surrounding tissues.(1) The innate and adaptive arms of the immune response are involved in the initiation, development and persistence of atherosclerosis.(2, 3) There is a significant body of evidence that different subsets of the immune cells, such as macrophages, dendritic cells, T and B lymphocytes, are present within the aortas of healthy and atherosclerosis-prone mice(4). Additionally, immune cells are found in the surrounding aortic adventitia which suggests an important role of this tissue in atherogenesis.(2) For some time, the quantitative detection of different types of immune cells, their activation status, and the cellular composition within the aortic wall was limited by RT-PCR and immunohistochemical methods for the study of atherosclerosis. Few attempts were made to perform flow cytometry using human aortas, and a number of problems, such as a high autofluorescence, have been reported(5,6). Human atherosclerotic plaques were digested with collagenase 1, and free cells were collected and stained for CD14+/CD11c+ to highlight macrophage-derived foam cells. In this study, a "mock" channel was used to avoid false-positive staining.(6) Necrotic materials accumulating during the digestion process give rise in a large amount of debris that generates a high autofluorescence in aortic samples. To resolve this problem, a panel of negative and positive controls has been proposed, but only double staining could be applied in these samples. We have developed a new flow cytometry-based method(7) to analyze the immune cell composition and characterize the activation, proliferation, differentiation of immune cells in healthy and atherosclerosis-prone aorta. This method allows the investigation of the immune cell composition of the aortic wall and opens possibilities to use a broad spectrum of immunological methods for investigations of immune aspects of this disease.