Small intestinal submucosa as a small-caliber venous graft: a novel model for hepatocyte transplantation on synthetic biodegradable polymer scaffolds with direct access to the portal venous system

BACKGROUND/PURPOSE: Hepatotrophic factors in the portal blood are critically important for the survival of heterotopically transplanted hepatocytes. Currently, no model exists for the implantation of hepatocytes on biodegradable polymer scaffolds with direct access to the portal blood. This study investigates the use of small intestinal submucosa (SIS) as a small-caliber venous conduit that may be used for the implantation of tissue-engineered liver. METHODS: SIS was prepared from segments of rat jejunum and implanted as a venous conduit between the portal vein and inferior vena cava in 26 heparinized Lewis rats. Venograms were performed periodically, and the grafts were harvested at various time-points and examined by scanning electron microscopy (SEM) and histology. Von Willebrand Factor (vWF) staining was performed to assess endothelialization. RESULTS: Five rats died of technical complications. Seventeen of 21 rats (81%) maintained patent grafts at the time of death up to 8 weeks. Venograms demonstrated patent grafts at 3 and 8 weeks. SEM results showed a smooth luminal surface with endothelial-like cells by 3 weeks. Histology demonstrated a confluent luminal endothelial monolayer, absence of thrombus, and neovascularization in the SIS graft. VWF staining results were positive, confirming the growth of endothelial cells on the luminal surface. In preliminary studies, implantation of hepatocytes seeded on biodegradable polymer tubes into the SIS graft demonstrated clusters of viable cells after 2 days. CONCLUSIONS: Rat SIS can be prepared readily, maintains high patency as a small-caliber venous graft, and may be a useful model for the transplantation of tissue-engineered liver with access to the portal circulation.     

Branched Chain Amino Acids Promote ATP Production Via Translocation of Glucose Transporters

PurposeWe have previously shown that maintenance of ATP levels is a promising strategy for preventing neuronal cell death, and that branched chain amino acids (BCAAs) enhanced cellular ATP levels in cultured cells and antagonized cell death. BCAAs attenuated photoreceptor degeneration and retinal ganglion cell death in rodent models of retinal degeneration or glaucoma. This study aimed to elucidate the mechanisms through which BCAAs enhance ATP production.MethodsIntracellular ATP concentration was measured in HeLa cells under glycolysis and citric acid cycle inhibited conditions. Next, glucose uptake was quantified in HeLa cells and in 661W retinal photoreceptor-derived cells under glycolysis inhibition, endoplasmic reticulum stress, and glucose transporters (GLUTs) inhibited conditions, by measuring the fluorescence of fluorescently labeled deoxy-glucose analog using flow cytometry. Then, the intracellular behavior of GLUT1 and GLUT3 were observed in HeLa or 661W cells transfected with enhanced green fluorescent protein-GLUTs.ResultsBCAAs recovered intracellular ATP levels during glycolysis inhibition and during citric acid cycle inhibition. BCAAs significantly increased glucose uptake and recovered decreased glucose uptake induced by endoplasmic reticulum stress or glycolysis inhibition. However, BCAAs were unable to increase intracellular ATP levels or glucose uptake when GLUTs were inhibited. Fluorescence microscopy revealed that supplementation of BCAAs enhanced the translocation of GLUTs proteins to the plasma membrane over time.ConclusionsBCAAs increase ATP production by promoting glucose uptake through promotion of glucose transporters translocation to the plasma membrane. These results may help expand the clinical application of BCAAs in retinal neurodegenerative diseases, such as glaucoma and retinal degeneration.     

Hyperlipidemia as a risk factor for Trousseau syndrome-related cerebral infarction in patients with advanced gastrointestinal cancer

Trousseau syndrome-related cerebral infarction rarely occurs during chemotherapy in patients with gastrointestinal (GI) cancer, and its clinical features remain unclear. The present study aimed to examine the clinical features of Trousseau syndrome-related cerebral infarction developed during chemotherapy for GI cancer. The present retrospective cohort study consecutively enrolled 878 patients with unresectable GI cancer who received chemotherapy at the Multidisciplinary Treatment Cancer Center, Kurume University Hospital (Kurume, Japan) between April 2014 and March 2020. Patients with colorectal cancer (n=308) were the most common, followed by those with pancreatic (n=242), gastric (n=222) and biliary tract (n=59) cancer, neuroendocrine tumors (n=34) and duodenal cancer (n=11). Among the 878 patients, Trousseau syndrome-related cerebral infarction occurred in 8 (0.9%) patients with a median age of 70.5 years (range, 58–75 years), and 50% of the patients were male (4/8). In total, 3 patients had gastric cancer, 3 had pancreatic cancer and 2 had biliary tract cancer. A greater percentage of patients with Trousseau syndrome-related cerebral infarction had hyperlipidemia (38.0%) than those without (8.2%; P=0.005). Hyperlipidemia was a risk factor for occurrence of Trousseau syndrome-related cerebral infarction with an odds ratio of 7.009 (95% confidence interval, 1.785-27.513). Trousseau syndrome-related cerebral infarction developed during GI chemotherapy was rare and hyperlipidemia may predict its onset.     

Simultaneous detections of 27 cytokines during cerebral wound healing by multiplexed bead-based immunoassay for wound age estimation

Quantification of 27 cytokines following cerebral wounding was performed for wound age estimation. The cytokines evaluated included interleukin (IL)-1alpha, IL-1beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12 p40, IL-12 p70, IL-15, IL-17, IL-18, basic fibroblast growth factor (bFGF), granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), Interferon-gamma (IFN-gamma), keratinocyte derived cytokine (KC), leukemia inhibitory factor (LIF), macrophage-colony stimulating factor (M-CSF), monokine inducible by interferon gamma (MIG), macrophage inflammatory protein (MIP)-1 alpha, MIP 2, platelet-derived growth factor BB (PDGF BB), regulated upon activation, normal T-cell expressed, and secreted (Rantes), tumor necrosis factor-alpha (TNF-alpha), and vascular endothelial growth factor (VEGF). The proliferation of glial cells as well as the infiltration of inflammatory cells were also evaluated. Although astroglia proliferated from 72 hours post-injury, inflammatory cell dynamics were generally steady. Among cytokines analyzed in the present study, IL-1beta, IL-5, IL-6, IL-12 p40, G-CSF, IFN-gamma, KC, LIF, MIP2, and PDGF BB increased during the early phase of cerebral wound healing, and M-CSF increased during the middle phase, while IL-15, IL-18, and MIG increased during the late phase. In contrast, IL-1alpha, IL-10, IL-12 p70, and TNF-alpha were suppressed throughout the cerebral wound healing process. Based on our findings, quantitative cytokine analyses at the cerebral wound site may be a useful tool for wound age estimation. Further, this study suggests that multiplex data gained from the same sample using a single methodology demonstrates highly accurate cytokine interactions during the process of cerebral wound healing.     

Accurate,safe, and rapid method of intraoperative tumor identification for totally laparoscopic distal gastrectomy: injection of mixed fluid of sodium hyaluronate and patent blue

Background

In totally laparoscopic distal gastrectomy, determining the resection line with safe proximal margins is often difficult, particularly for tumors located in a relatively upper area. This is because, in contrast to open surgery, identifying lesions by palpating or opening the stomach is essentially impossible. This study introduces a useful method of tumor identification that is accurate, safe, and rapid.

Methods

On the operation day, after inducing general anesthesia, a mixture of sodium hyaluronate and patent blue is injected into the submucosal layer of the proximal margin. When resecting stomach, all marker spots should be on the resected side. In all cases, the proximal margin is examined histologically by using frozen sections during the operation.

Results

From October 2009 to September 2011, a prospective study that evaluated this method was performed. A total of 34 patients who underwent totally laparoscopic distal gastrectomy were enrolled in this study. Approximately 5 min was required to complete the procedure. Proximal margins were negative in all cases, and the mean ± standard deviation length of the proximal margin was 23.5 ± 12.8 mm. No side effects, such as allergy, were encountered.

Conclusions

As a method of tumor identification for totally laparoscopic distal gastrectomy, this procedure appears accurate, safe, and rapid.