Search

Chandra Kumar Elechalawar,1 Md Nazir Hossen,1 Priya Shankarappa,2 Cody J Peer,2 William D Figg,2 J David Robertson,3 Resham Bhattacharya,4 Priyabrata Mukherjee1,5 1Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; 2Clinical Pharmacology Program, National Cancer Institute, Bethesda, MD 20892, USA; 3Department of Chemistry and University of Missouri Research Reactor, University of Missouri, Columbia, MO 65211, USA; 4Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; 5Peggy and Charles Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USACorrespondence: Priyabrata MukherjeeDepartment of Pathology, The University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC-1409B, Oklahoma City, OK 73104, USATel +1 405-271-1133Fax +1 405-271-2472Email Priyabrata-Mukherjee@ouhsc.eduIntroduction and Objective: Pancreatic cancer (PC) is characterized by a robust desmoplastic environment, which limits the uptake of the standard first-line chemotherapeutic drug gemcitabine. Enhancing gemcitabine delivery to the complex tumor microenvironment (TME) is a major clinical challenge. Molecular crosstalk between pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs) plays a critical role in desmoplastic reaction in PCs. Herein, we report the development of a targeted drug delivery system to inhibit the proliferation of PCCs and PSCs in vitro. Using gold nanoparticles as the delivery vehicle, the anti-EGFR antibody cetuximab (C225/C) as a targeting agent, gemcitabine as drug and polyethylene glycol (PEG) as a stealth molecule, we created a series of targeted drug delivery systems.Methods: Fabricated nanoconjugates were characterized by various physicochemical techniques such as UV-Visible spectroscopy, transmission electron microscopy, HPLC and instrumental neutron activation analysis (INAA).Results and Conclusion: Targeted gemcitabine delivery systems containing mPEG-SH having molecular weights of 550 Da or 1000 Da demonstrated superior efficacy in reducing the viability of both PCCs and PSCs as compared to their non-targeted counterparts. EGFR-targeted pathway was further validated by pre-treating cells with C225 followed by determining cellular viability. Taken together, in our current study we have developed a PEGylated targeted nanoconjugate ACG44P1000 that showed enhanced selectivity towards pancreatic cancer cells and pancreatic stellate cells, among others, for gemcitabine delivery. We will investigate the ability of these optimized conjugates to inhibit desmoplasia and tumor growth in vivo in our future studies.Keywords: pancreatic cancer, gold nanoparticles, PEGylation, drug delivery

Matrix metalloproteinases (MMPs), particularly gelatinases (MMP-2/-9), are involved in neurovascular impairment after stroke. Detection of gelatinase activity in vivo can provide insight into blood-brain barrier disruption, hemorrhage, and nerve cell injury or death. We applied gelatinase-activatable cell-penetrating peptides (ACPP) with a cleavable l-amino acid linker to examine gelatinase activity in primary neurons in culture and ischemic mouse brain in vivo We found uptake of Cy5-conjugated ACPP (ACPP-Cy5) due to gelatinase activation both in cultured neurons exposed to n-methyl-d-aspartate and in mice after cerebral ischemia. Fluorescence intensity was significantly reduced when cells or mice were treated with MMP inhibitors or when a cleavage-resistant ACPP-Cy5 was substituted. We also applied an ACPP dendrimer (ACPPD) conjugated with multiple Cy5 and/or gadolinium moieties for fluorescence and magnetic resonance imaging (MRI) in intact animals. Fluorescence analysis showed that ACPPD was detected in sub-femtomole range in ischemic tissues. Moreover, MRI and inductively coupled plasma mass spectrometry revealed that ACPPD produced quantitative measures of gelatinase activity in the ischemic region. The resulting spatial pattern of gelatinase activity and neurodegeneration were very similar. We conclude that ACPPs are capable of tracing spatiotemporal gelatinase activity in vivo, and will therefore be useful in elucidating mechanisms of gelatinase-mediated neurodegeneration after stroke.

Six level channel theory, most commonly associated with the herbal classic Discussion of Cold Damage (??? Shang Hán Lùn), also lies at the core of traditional acupuncture theory. This article explores a unique technique for testing the applicability of such classical theory during acupuncture practice, which is drawn from the palpatory diagnostic approach of Professor Wang Ju-Yi (Beijing). The acupuncture system advocated by the late Tung Ching-Chang (Taiwan), for example, often utilises six-level theory to create effective acupuncture prescriptions. By combining knowledge of this popular acupuncture approach with careful palpation of the channels, greater precision of diagnosis and treatment can be achieved. By combining classical theory with manual diagnosis, acupuncturists can resolve even the most complex pathologies. Two case studies are included to illustrate the method in practice. [ABSTRACT FROM AUTHOR]

Previous studies show significantly decreased levels of zinc transporter 1 (ZnT-1) in the brain of subjects with mild cognitive impairment (MCI) but significantly increased ZnT-1 in late stage AD (LAD). However, the reason for the apparent dichotomy is unclear. Based on in vivo studies that show animals provided a zinc (Zn) deficient diet demonstrate decreased brain ZnT-1, we used inductively coupled plasma-mass spectrometry (ICP-MS) to quantify serum Zn levels from 18 living mild to moderate AD patients (9 men, 9 women), 19 MCI patients (9 men, 10 women) and 16 age-matched normal control (NC) subjects (9 men, 7 women). Zinc levels for all subjects were not significantly different among any of the three subject groups. However, there was a statistically significant decrease of serum Zn (11.7 +/- 0.5 microM) in men with MCI compared to women with MCI (13.7 +/- 0.6 microM) and NC men (13.9 +/- 0.6 microM). Serum Zn levels in probable AD patients were comparable to those in NC subjects. Overall, these data suggest a significant decrease of serum Zn in men with MCI, may explain the loss of ZnT-1 observed in previous studies and suggest there may be more pronounced sex differences in MCI than were previously recognized. [ABSTRACT FROM AUTHOR]

Objective: To assess whether percent true calcium absorption (alpha) is normal and whether supplementation with placebo, vitamin D3 (2,000 IU/day), calcium (1,000 mg/day), or vitamin D3 plus calcium improves alpha, mineral metabolism, or bone mass accrual in children with arthritis.Methods: Eighteen children received all 4 treatments, each for 6 months, in 4 different, randomly assigned orders. Changes in levels of 25-hydroxyvitamin D (25[OH]D), 1,25-dihydroxyvitamin D (1,25[OH][2]D), parathyroid hormone, bone turnover markers, and minerals and in bone mineral content were measured. Calcium absorption was determined with a dual stable isotope method using [48]Ca administered intravenously and [46]Ca administered orally, and measuring [48]Ca,[ 46]Ca, and [42]Ca in a 24-hour urine specimen by high-resolution inductively coupled plasma mass spectroscopy. Wilcoxon's signed rank test was used both to identify significant change over the treatment period with a given regimen and to compare change with an experimental treatment versus change with placebo.Results: Percent true calcium absorption was in the lower-normal range and did not differ by treatment (mean +/- SD 28.3 +/- 20.2% with placebo, 26.1 +/- 12.1% with calcium, 19.2 +/- 11.7% with vitamin D3, and 27.1 +/- 16.5% with vitamin D3 plus calcium). With vitamin D3 and vitamin D3 plus calcium treatment, 25(OH)D levels were increased and 1,25(OH)[2]D levels were maintained. Serum calcium levels were increased only with vitamin D3 and vitamin D3 plus calcium treatment. Levels of bone turnover markers and increases in bone mineral content did not differ by treatment.Conclusion: The findings of this study indicate that percent true calcium absorption is low-normal in children with arthritis. Vitamin D3 at 2,000 IU/day increases serum 25(OH)D and calcium levels but does not improve bone mass accretion. Calcium at 1,000 mg/day also failed to improve bone mass. [ABSTRACT FROM AUTHOR]

By exploiting the self-therapeutic properties of gold nanoparticles (GNPs) a molecular axis that promotes the growth of high-grade serous ovarian cancer (HGSOC), one of the deadliest gynecologic malignancies with poorly understood underlying molecular mechanisms, has been identified. The biodistribution and toxicity of GNPs administered by intravenous or intraperitoneal injection, both as a single dose or by repeated dosing over two weeks are first assessed; no biochemical or histological toxicity to vital organs is found. Using an orthotopic patient-derived xenograft (PDX) model of HGSOC, the authors then show that GNP treatment robustly inhibits tumor growth. Investigating the molecular mechanisms underlying the GNP efficacy reveals that GNPs downregulate insulin growth factor binding protein 2 (IGFBP2) by disrupting its autoregulation via the IGFBP2/mTOR/PTEN axis. This mechanism is validated by treating a cell line-based human xenograft tumor with GNPs and an mTOR dual-kinase inhibitor (PI-103), either individually or in combination with GNPs; GNP and PI-103 combination therapy inhibit ovarian tumor growth similarly to GNPs alone. This report illustrates how the self-therapeutic properties of GNPs can be exploited as a discovery tool to identify a critical signaling axis responsible for poor prognosis in ovarian cancer and provides an opportunity to interrogate the axis to improve patient outcomes., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

This paper reports experimental results of a prototype titanium surface ionization source. For the first time, a lanthanide ion beam has been produced with a surface ionizer composed completely of titanium metal. Titanium does not readily activate with neutron irradiation. This offers the potential for inserting an ion source made of titanium directly into a reactor with a pre-loaded non-radioactive lanthanide target. This seamlessly integrates target irradiation with isotope separation, eliminating post irradiation sample manipulation. Samarium ion beam currents up to 960 nA have been produced in an off-line test bench equipped with rudimentary beam optics. This is a crucial step toward the development of an ionization source adopted for the electromagnetic isotope separator (EMIS) facility, which has been designed for high throughput separations of radioactive 153 Sm and other lanthanides of interest in the field of nuclear medicine. The ion current and important factors affecting the performance of the ion source, such as the ionizer temperature and thermal gradient, are discussed. The experimental results are presented together with a discussion of future modifications to optimize the overall surface ionization source performance., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Succinate dehydrogenase (SDH) is an inner mitochondrial membrane protein complex that links the Krebs cycle to the electron transport system. It can produce significant amounts of superoxide ([Formula: see text]) and hydrogen peroxide (H 2 O 2 ); however, the precise mechanisms are unknown. This fact hinders the development of next-generation antioxidant therapies targeting mitochondria. To help address this problem, we developed a computational model to analyze and identify the kinetic mechanism of [Formula: see text] and H 2 O 2 production by SDH. Our model includes the major redox centers in the complex, namely FAD, three iron-sulfur clusters, and a transiently bound semiquinone. Oxidation state transitions involve a one- or two-electron redox reaction, each being thermodynamically constrained. Model parameters were simultaneously fit to many data sets using a variety of succinate oxidation and free radical production data. In the absence of respiratory chain inhibitors, model analysis revealed the 3Fe-4S iron-sulfur cluster as the primary [Formula: see text] source. However, when the quinone reductase site is inhibited or the quinone pool is highly reduced, [Formula: see text] is generated primarily by the FAD. In addition, H 2 O 2 production is only significant when the enzyme is fully reduced, and fumarate is absent. Our simulations also reveal that the redox state of the quinone pool is the primary determinant of free radical production by SDH. In this study, we showed the importance of analyzing enzyme kinetics and associated side reactions in a consistent, quantitative, and biophysically detailed manner using a diverse set of experimental data to interpret and explain experimental observations from a unified perspective., Competing Interests: Conflict of interest—The authors declare that they have no conflicts of interest with the contents of this article., (© 2020 Manhas et al.)