Micropyramid-patterned, oxygen-permeable bottomed dish for high density culture of pancreatic islets.

The need for maintaining cell-spheroid viability and function within high-density cultures is unmet for various clinical and experimental applications, including cell therapies. One immediate application is for transplantation of pancreatic islets, a clinically recognized treatment option to cure type 1 diabetes; islets are isolated from a donor for subsequent culture prior to transplantation. However, high seeding conditions cause unsolicited fusion of multiple spheroids, thereby limiting oxygen diffusion to induce hypoxic cell death. Here we introduce a culture dish incorporating a micropyramid-patterned surface to prevent the unsolicited fusion and oxygen-permeable bottom for optimal oxygen environment. A 400µm-thick, oxygen-permeable polydimethylsiloxane sheet topped with micropyramid pattern of 400µm-base and 200µm-height was fabricated to apply to the 24-well plate format. The micropyramid pattern separated the individual pancreatic islets to prevent the fusion of multiple islets. This platform supported the high oxygen demand of islets at high seeding density at 260 islet equivalents cm-2, a 2-3-fold higher seeding density compared to the conventional islet culture used in a preparation for the clinical islet transplantations, demonstrating improved islet morphology, metabolism and function in a 4 d-culture. Transplantation of these islets into immunodeficient diabetic mice exhibited significantly improved engraftment to achieve euglycemia compared to islets cultured in the conventional culture wells. Collectively, this simple design modification allows for high-density cultures of three-dimensional cell spheroids to improve the viability and function for an array of investigational and clinical replacement tissues.

Adhesion Characteristics of Human Pancreatic Islets, Duct Epithelial Cells, and Acinar Cells to a Polymer Scaffold.

We reported in 2018 that among several extracellular matrices, fibronectin, type I collagen, type IV collagen, laminin I, fibrinogen, and bovine serum albumin, fibronectin is particularly useful for adhesion of porcine pancreatic tissue. Subsequently, we developed a technology that enables the chemical coating of the constituent motifs of fibronectin onto cell culture dishes. In this experiment, we used islets (purity ≥ 90%), duct epithelial cells (purity ≥ 60%), and acinar cells (purity ≥ 99%) isolated from human pancreas according to the Edmonton protocol published in 2000 and achieved adhesion to the constituent motifs of fibronectin. A solution including cGMP Prodo Islet Media was used as the assay solution. In islets, adhesion was enhanced with the constitutive motifs of fibronectin compared with uncoated islets. In the functional evaluation of islets, insulin mRNA expression and insulin secretion were enhanced by the constitutive motif of fibronectin compared with non-coated islets. The stimulation index was comparable between non-coated islets and fibronectin motifs. In duct epithelial cells, adhesion was mildly promoted by the fibronectin component compared with non-coated component, while in acinar cells, adhesion was inhibited by the fibronectin component compared with the non-coated component. These data suggest that the constitutive motifs of fibronectin are useful for the adhesion of islets and duct epithelial cells.

Immunohistochemical comparison of biomarker expression in biopsy and surgical specimens of non-small cell lung cancer.

BACKGROUND: Single tumors may show heterogeneity, and it is unclear whether biomarker expression in surgical and diagnostic biopsy samples correlates. MATERIALS AND METHODS: We retrospectively identified lung cancer patients who were diagnosed by biopsy and underwent surgery between January 2007 and October 2010 at the Shimane University Hospital, Shimane, Japan. Thirty-two patients were identified. The expression of four predictive biomarkers was assessed, namely excision repair cross-complementing gene 1 (ERCC1), ribonucleotide diphosphate reductase M1 (RRM1), thymidylate synthase (TS), and class III beta-tubulin (BT). We also compared immunohistochemical staining in diagnostic biopsy and corresponding resected surgical samples. RESULTS: Moderate correlation was seen between the expression of ERCC1, RRM1, TS, and BT in the biopsy and surgical specimens, with r values of 0.512 (p=0.003), 0.411 (p=0.020), 0.475 (p=0.006), and 0.404 (p=0.027), respectively. CONCLUSION: Assessment of biopsy samples with immunohistochemical staining is a feasible and reliable method for use in clinical decision making.

Efficacy and safety of piperacillin/tazobactam versus biapenem in late elderly patients with nursing- and healthcare-associated pneumonia.

Pneumonia is associated with an extremely high mortality rate in patients of late elderly age. Piperacillin/tazobactam and carbapenems are drugs of first choice for hospitalized patients with potentially resistant bacteria. We compared the efficacy and safety of piperacillin/tazobactam and biapenem. Among elderly patients with nursing- and healthcare-associated pneumonia, we extracted 53 patients treated with piperacillin/tazobactam and 53 patients treated with biapenem who were matched for sex, age, and severity of pneumonia. The average age was more than 80 years; most of the patients were middle- to oldest old in age. Although clinical efficacy was equally good, patients in the piperacillin/tazobactam group achieved significantly faster improvements on chest X-ray and body temperature on day 7. However, in the piperacillin/tazobactam group, nephrotoxicity frequently led to a need for a reduction in the dose or complete discontinuation of treatment. The average age of patients who developed significant nephrotoxicity was high, at 83.2 years. The biapenem group exhibited significantly better continuation of treatment than the piperacillin/tazobactam group. Toxicity profiles were different between the two groups. Hepatic toxicity was significantly higher in the biapenem group, whereas nephrotoxicity was significantly more common in the piperacillin/tazobactam group. Rate of decrease in bacteria was equally good between the two groups. Providing careful follow-up and conducting more detailed examinations, including studies to determine optimal dose and timing of administration, are necessary for the treatment of late elderly patients with numerous underlying diseases and potential organ dysfunctions.