Translational Pharmacokinetic-Toxicodynamic Model of Myelosuppression for Dose Optimization in Combination Chemotherapy of Capecitabine and Oxaliplatin from Rats to Humans.

XELOX therapy, which comprises capecitabine and oxaliplatin, is the standard first-line chemotherapeutic regimen for colorectal cancer. However, its myelosuppressive effects pose challenges for its clinical management. Mathematical modeling combining pharmacokinetics (PK) and toxicodynamics (TD) is a promising approach for optimizing dosing strategies and reducing toxicity.

Pharmacokinetic-toxicodynamic Modeling to Elucidate the Involvement of Dorsal Root Ganglion Neuron in Oxaliplatin-induced Peripheral Neuropathy.

Background/aim: Oxaliplatin (L-OHP)-induced peripheral neuropathy (OIPN) limits L-OHP dosage due to nerve cell damage in the dorsal root ganglion (DRG) caused by platinum (Pt). Despite various recommended approaches for OIPN management, no effective approach has been established. The aim of this study was to evaluate Pt distribution into DRG after repeat administrations of L-OHP in rats and to develop a pharmacokinetic-toxicodynamic (PK-TD) model using Pt concentrations in DRG to predict neuropathy severity.

Translational PK-PD/TD modeling of antitumor effects and peripheral neuropathy in gemcitabine and nab-paclitaxel chemotherapy from xenograft mice to patients for optimal dose and schedule.

Purpose: Gemcitabine and nab-paclitaxel (GnP) treatment, the standard first-line chemotherapy for unresectable pancreatic cancer, often causes peripheral neuropathy (PN). To develop alternative dosing strategies to avoid severe PN, understanding the relationship between pharmacokinetics (PK) and pharmacodynamics/toxicodynamics (PD/TD) is necessary. We established a PK-PD/TD model of GnP treatment to develop an optimal dose schedule.

Mobilization of Circulating Tumor Cells after Short- and Long-Term FOLFIRINOX and GEM/nab-PTX Chemotherapy in Xenograft Mouse Models of Human Pancreatic Cancer.

Mobilization of CTCs after various types of therapy, such as radiation therapy, has been reported, but systematic study of CTCs after chemotherapy remained quite limited. In this study, we sequentially examined CTC numbers after single-dose and repetitive-dose chemotherapy, including FORFIRINOX (FFX) and Gemcitabine and nab-Paclitaxel (GnP) using two pancreatic cancer xenograft models. CTC was detected by the immunocytology-based microfluidic platform.

Pharmacokinetic evaluation of oxaliplatin combined with S-1 (SOX) chemotherapy in a rat model of colorectal cancer with acute kidney injury: predictive renal biomarkers for dose optimisation.

Dose adjustment based on renal function is essential in S-1, which contains the 5‑fluorouracil prodrug tegafur, and platinum-based agent oxaliplatin (SOX) combination chemotherapy for colorectal cancer in patients with chronic kidney disease. However, limited evidence on dose adjustment in acute kidney injury (AKI) and challenges in determining dosing strategies. This study investigated the pharmacokinetics of SOX chemotherapy and renal biomarkers in rats.

Children's Diet and Nutrition in the Aftermath of the Torrential Rain Disaster in Western Japan: An Evaluation of Support Activities by Dietitians to Alleviate Mothers' Anxieties.

Objective: The purpose of this study was to clarify whether the support activities of dietitians during disasters were able to address the problems faced by mothers about their children's diet and nutrition.

Methods: Dietitians (7 in total) and mothers (8) were selected by the snowball sampling method. Semi-structured interviews were used to conduct focus group interviews about children's diet and nutrition.

A Pharmacokinetic-Pharmacodynamic Model Predicts Uracil-tegafur Effect on Tumor Shrinkage and Myelosuppression in a Colorectal Cancer Rat Model.

Background/aim: Oral 5-fluorouracil (5-FU)-based prodrugs, used in cancer chemotherapeutic regimens, exhibit large inter- and intra-patient variability in plasma 5-FU concentrations, contributing to treatment failure. Although dosage determination criteria according to plasma drug concentrations are required, the relationship between pharmacokinetics and drug response after multiple oral 5-FU derivative administrations remain unknown.

Materials And Methods: We evaluated the pharmacokinetics and pharmacodynamics/toxicodynamics of uracil-tegafur (UFT) after multiple administrations in colorectal cancer (CRC) model rats, and applied a pharmacometric approach to describe the time-course alterations of plasma 5-FU concentrations and tumor shrinkage.

Predictive marker for exposure-driven haematological toxicity of tegafur-uracil and proposed modified-dosage regimen by pharmacometric approach in rats.

Myelosuppression is a dose-limiting toxicity of uracil-tegafur (UFT), which contains uracil and the 5‑fluorouracil prodrug tegafur, and inhibits the continuation of chemotherapy, causing treatment failure. A proper dosing strategy to avoid severe myelosuppression-induced discontinuation of chemotherapy is required.Plasma drug concentrations were determined in rats after single oral UFT administration of 15, 30, or 60 mg/kg.

Population Pharmacokinetic Model-Based Evaluation of Intact Oxaliplatin in Rats with Acute Kidney Injury.

Acute kidney injury (AKI) complicates the dosing strategies of oxaliplatin (L-OHP) and the requirement for L-OHP dose reduction in patients with renal failure remains controversial. The objective of this study is to assess the impact of AKI on the pharmacokinetics (PK) of intact L-OHP and simulate the relationship between the degree of renal function and intact L-OHP exposures using a population PK model. Intact L-OHP concentrations in plasma and urine after L-OHP administration were measured in mild and severe AKI models established in rats through renal ischemia-reperfusion.

Prolonged Maternal and Child Health, Food and Nutrition Problems after the Kumamoto Earthquake: Semantic Network Analysis of Interviews with Dietitians.

Infants need sufficient nutrients even during disasters. Only qualitative descriptive analysis has been reported regarding nutritional problems of mothers and children after the Kumamoto earthquake, and non-subjective analysis is required. This study examined issues concerning maternal and child health, food and nutrition after the Kumamoto earthquake using automatic computer quantitative analysis from focus group interviews (FGIs).

Cytology-based Detection of Circulating Tumour Cells in Human Pancreatic Cancer Xenograft Models With Mutation.

Background/aim: To examine the dynamics of circulating tumour cells (CTCs) in pancreatic cancer (PC), new mouse CTC models from human PC xenografts were developed.

Materials And Methods: Orthotopic (pancreas) and heterotopic (subcutaneous) transplantation models using GFP-tagged SUIT-2 PC cells were prepared. Using a cytology-based CTC detection platform, CTCs and metastasis were compared.

Application of Pharmacometrics of 5-Fluorouracil to Personalized Medicine: A Tool for Predicting Pharmacokinetic-Pharmacodynamic/Toxicodynamic Responses.

Recently, therapeutic drug monitoring of 5-fluorouracil (5-FU), the key chemotherapeutic drug for colorectal cancer, has been applied in daily clinical practice and has contributed towards improving clinical outcomes. However, current dose modifications are based only on values of the area under the plasma concentration-time profile, which are simply calculated from plasma 5-FU concentrations and infusion periods. When dose-limiting toxicities occur, the dosing is empirically reduced or discontinued, leading to treatment failure.

Comparison of In Vivo Transportability of Anti-Methicillin-Resistant Staphylococcus aureus (MRSA) Agents Into Intracellular and Extracellular Tissue Spaces in Rats.

The pathogenic bacterium Staphylococcus aureus can penetrate host cells. However, intracellular S. aureus is not considered during antimicrobial agent selection in clinical chemotherapy because of the lack of information about drug transportability into cells in vivo.

Effect of intact oxaliplatin in plasma on a cold allodynia after multiple administrations in colorectal cancer model rats.

Background: Oxaliplatin (L-OHP)-induced acute neuropathy is a major factor for influencing treatment compliance in patients receiving chemotherapy for colorectal cancer (CRC). Acute neuropathy is caused by the intact L-OHP affecting the function of transient receptor potential vanilloid 1 (TRPV1) channel. In this study, the effectiveness of the detection of the intact L-OHP and the association with the severity of L-OHP-induced acute neuropathy were investigated using a rat model of CRC.

Population Pharmacokinetic Model-Based Evaluation of Circadian Variations in Plasma 5-Fluorouracil Concentrations During Long-Term Infusion in Rats: A Comparison With Oral Anticancer Prodrugs.

Circadian fluctuations in the plasma concentration of 5-fluorouracil impede the accurate estimation of target therapeutic concentrations in the long-term infusion or oral 5-fluorouracil-based prodrug regimen. We evaluated the circadian patterns of plasma 5-fluorouracil concentrations in rats using population pharmacokinetic model. Rats were divided into 2 groups, and a continuous infusion (50 mg/m/h) for 48 h was initiated with or without a bolus injection of 60 mg/kg 5-fluorouracil.

Assessment of pharmacokinetic variations of capecitabine after multiple administration in rats: a physiologically based pharmacokinetic model.

Purpose: Capecitabine is a prodrug of 5-fluorouracil (5-FU) used for the treatment of colorectal cancer, with a two-week course of administration. However, the variance in plasma concentration and metabolic enzyme activities after multiple administration of capecitabine and its metabolites is unknown. The aim of this study was to identify the variance and predict the plasma concentration profile of capecitabine and its metabolites, using metabolic enzyme activities, to develop a more effective and safer medication.

Pharmacokinetics and lung distribution of macrolide antibiotics in sepsis model rats.

Recent studies have shown azithromycin-specific clinical efficacy against macrolide-resistant strains of , despite the low susceptibility of the bacteria . This discrepancy complicates dosing and selection for treatment of macrolide-resistant strains. Although phagocyte delivery of azithromycin to inflamed tissues is considered a possible factor for clinical efficacy, there is a lack of sufficient evidence, and other pharmacokinetic factors under systemic inflammation may contribute.

Assessment of Oxaliplatin-induced Chronic Neuropathy and Anticancer Efficacy Through Pharmacokinetic and Toxicodynamic Evaluation of a Rat Model of Colorectal Cancer.

Background/aim: Oxaliplatin-induced chronic neuropathy is a prominent factor for dose reduction and not completing all cycles of chemotherapy for patients with colorectal cancer (CRC). The aim of the study was to investigate the pharmacokinetics and toxicodynamics of oxaliplatin-induced chronic neuropathy in CRC rats to ensure effective management.

Materials And Methods: A rat model of CRC was developed using 1,2-Dimethylhydrazine and dextran sulfate.

Mechanism-based pharmacokinetic-pharmacodynamic (PK-PD) modeling and simulation of oxaliplatin for hematological toxicity in rats.

Oxaliplatin (L-OHP) is a platinum (Pt)-based anticancer agent and is widely used for treating gastroenterological cancer. However, L-OHP-induced hematological toxicity is a critical undesirable effect that limits the dose of L-OHP. An ideal chemotherapeutic strategy that avoids severe hematological toxicity while maintaining positive chemotherapeutic outcomes has not been established for L-OHP.

Association between the pharmacokinetics of capecitabine and the plasma dihydrouracil to uracil ratio in rat: A surrogate biomarker for dihydropyrimidine dehydrogenase activity.

Capecitabine is a 5-fluorouracil (5-FU) derivative that is used widely in the treatment of colorectal cancer. The plasma ratio of dihydrouracil (UH ) to uracil (Ura) is expected to gain relevance as an indirect-response biomarker to estimate the activity of dihydropyrimidine dehydrogenase (DPD). The latter is a rate-limiting enzyme in the catabolism of 5-FU in the capecitabine-based regimen.