Glucagon is unstable and undergoes degradation and aggregation in aqueous solution. For this reason, its use in portable pumps for closed loop management of diabetes is limited to very short periods. In this study, we sought to identify the degradation mechanisms and the bioactivity of specific degradation products. We studied degradation in the alkaline range, a range at which aggregation is minimized. Native glucagon and analogs identical to glucagon degradation products were synthesized. To quantify biological activity in glucagon and in the degradation peptides, a protein kinase A-based bioassay was used. Aged, fresh, and modified peptides were analyzed by liquid chromatography with mass spectrometry (LCMS). Oxidation of glucagon at the Met residue was common but did not reduce bioactivity. Deamidation and isomerization were also common and were more prevalent at pH 10 than 9. The biological effects of deamidation and isomerization were unpredictable; deamidation at some sites did not reduce bioactivity. Deamidation of Gln 3, isomerization of Asp 9, and deamidation with isomerization at Asn 28 all caused marked potency loss. Studies with molecular-weight-cutoff membranes and LCMS revealed much greater fibrillation at pH 9 than 10. Further work is necessary to determine formulations of glucagon that minimize degradation and fibrillation.
Based on these findings, a formulation of glucagon stabilized with curcumin, polysorbate-80, l-methionine, and albumin at alkaline pH in glycine buffer may be suitable for extended use in a portable pump in the setting of a bihormonal artificial endocrine pancreas.
Background: Acute myeloid leukemia (AML) with monocytic differentiation (M-AML) remains a diagnostic challenge largely due to lack of sensitive and specific markers for immature monocytes. The immunoglobulin-like inhibitory receptors, LILRB1 and LILRB4, are expressed on monocytes but have not yet been systematically evaluated in the clinical setting. Methods: We evaluated the diagnostic performance of LILRB1 and LILRB4 as monocytic markers for both immature and mature monocytes in comparison to other myelomonocytic markers including CD14, CD15, CD33, CD36, and CD64 in eight cases of control bone marrow (BM, 5) and peripheral blood (PB, 3), 64 cases of (M-AML), and 57 cases of AML without monocytic differentiation (NM-AML) by flow cytometric immunophenotyping.Results: In control BM, LILRB1 and LILRB4 were consistently expressed on monocytes at all stages of maturation, from CD34 + /CD14 − monocytic precursors to CD14 −/dim+ maturing and CD14 + mature monocytes. In M-AML, LILRB1 and LILRB4 were consistently expressed on monocytes, regardless of the degree of maturity, from CD14 −/dim+ monoblasts/promonocytes to CD14 + mature monocytes but were not expressed on myeloblasts.The diagnostic performances as a monocytic marker assessed by sensitivity/specificity were 100%/100% for LILRB1/LILRB4, 100%/82% for CD11b, 80%/100% for CD14, 100%/81% for CD64, 100%/58% for CD15/CD33, and 89%/97% for CD36/CD64.
Conclusion:The co-expression of LILRB1/LILRB4 outperformed other myelomonocytic markers as a highly sensitive and specific marker for monocytes at all stages of maturation and could reliably distinguish M-AML from NM-AML. LILRB4 additionally represents a novel therapeutic target for treating M-AML.
The aims of this study were to report the clinical outcomes in a cohort of men with high-risk prostate cancer treated with neoadjuvant docetaxel and mitoxantrone 10 years after treatment, identify pretreatment clinical parameters that may be predictors of recurrence, and describe tumor-infiltrating leukocytes present in radical prostatectomy specimens. We conducted a phase I/II study of neoadjuvant docetaxel and mitoxantrone before radical prostatectomy in high-risk localized prostate cancer to determine the feasibility of this combination and predictors of prostate cancer recurrence after cytotoxic chemotherapy. After 10 years of follow-up, 34 (63%) of 54 participants experience a recurrence. In univariate analysis, prostate-specific antigen (PSA) density (P=0.01), pathological stage (P=0.03), lymph node status (P<0.0001), seminal vesicle invasion (P=0.003), and tissue vascular endothelial growth factor (VEGF) expression (P=0.016) were significantly associated with recurrence. In multivariate analysis, only lymph node status, PSA density, and VEGF expression were significant predictors of disease recurrence. We used a tissue microarray for the first 50 participants to characterize the tumor-infiltrating lymphocytes and evaluate them for association with recurrence. We measured CD3, CD4, CD8, FoxP3, CD20, CD15, CD68, and CD163 by immunohistochemistry in both tumor and normal prostate specimens, but did not find an association between immunophenotype and recurrence. There was a significantly different density of CD68 and CD163 cells between normal and tumor tissue. Lymph node status, PSA density, and tissue VEGF expression predict recurrence after chemotherapy for high-risk prostate cancer. Additional studies are needed to determine the potential benefit of chemotherapy in the neoadjuvant setting.
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