1.Quantitative determination of erlotinib in human serum using competitive enzyme-linked immunosorbent assay
Yamamoto YUTA ; Saita TETSUYA ; Yamamoto YUTARO ; Shin MASASHI
Journal of Pharmaceutical Analysis 2018;8(2):119-123
A selective and sensitive competitive enzyme-linked immunosorbent assay (ELISA) method was developed and validated for the quantification of erlotinib in 50μL of samples of human serum. Anti-erlotinib serum was obtained by immunizing mice with an antigen conjugated with bovine serum albumin and 3,4-bis(2-methoxyethoxy)benzoic acid using the N-succinimidyl ester method. Enzyme labeling of erlotinib with horseradish peroxidase was similarly performed using 3,4-bis(2-methoxyethoxy)benzoic acid. A simple competitive ELISA for erlotinib was developed using the principle of direct competition between erlotinib and the enzyme marker for anti-erlotinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Serum erlotinib concentrations lower than 40 ng/mL were reproducibly measurable using the ELISA. This ELISA was specific to erlotinib and showed very slight cross-reactivity (6.7%) with a major metabolite, O-desmethyl erlotinib. Using this assay, drug levels were easily measured in the blood of mice after oral administration of erlotinib at a single dose of 30 mg/kg. ELISA should be used as a valuable tool for therapeutic drug monitoring and in pharmacokinetic studies of erlotinib.
2.Development of a competitive enzyme-linked immunosorbent assay for therapeutic drug monitoring of afatinib
Sogawa RINTARO ; Saita TETSUYA ; Yamamoto YUTA ; Kimura SAKIKO ; Narisawa YUTAKA ; Kimura SHINYA ; Shin MASASHI
Journal of Pharmaceutical Analysis 2019;9(1):49-54
Afatinib is an oral tyrosine kinase inhibitor (TKI) approved for treating advanced non-small cell lung cancer. It is necessary to develop a simple quantification method for TKIs in order to facilitate therapeutic drug monitoring (TDM) in clinical settings. This study sought to develop a simple and sensitive com-petitive enzyme-linked immunosorbent assay (ELISA) to quantify afatinib in plasma for routine phar-macokinetic applications. An anti-afatinib antibody was obtained using (S)-N-4-(3-chloro-4-fluor-ophenyl)-7-(tetrahydrofuran-3-yloxy)-quinazoline-4,6-diamine (CTQD), which has the same sub-structure as afatinib, as a hapten. Enzyme labeling of afatinib with horseradish peroxidase was similarly performed using CTQD. A simple competitive ELISA for afatinib was developed based on the principle of direct competition between afatinib and the enzyme marker for the anti-afatinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Plasma afatinib concentrations below the limit of quantification of 30 pg/mL were reproducibly measurable. Also, the values of plasma afatinib levels measured from 20 patients were comparable with those measured by high-performance liquid chromatography, and there was a strong correlation between the values determined by both methods (Y = 0.976X – 0.207, r = 0.975). As indicated by its specificity and sensitivity, this newly developed ELISA for afatinib is an important tool for TDM and studies of the pharmacokinetics of afatinib.
3.Effect of duration from lingual nerve injury to undergoing microneurosurgery on improving sensory and taste functions: retrospective study
Takashi NAKANISHI ; Yuta YAMAMOTO ; Kensuke TANIOKA ; Yukari SHINTANI ; Itaru TOJYO ; Shigeyuki FUJITA
Maxillofacial Plastic and Reconstructive Surgery 2019;41(1):61-
BACKGROUND:
The prognosis of recovery following microneurosurgery for injured lingual nerves varies among individual cases. This study aimed to investigate if recovery ratios of sensory and taste functions are improved by the microneurosurgery within 6 months after lingual nerve injury.
METHODS:
We retrospectively assessed 70 patients who underwent microneurosurgery at the Wakayama Medical University Hospital for lingual nerve injuries between July 2004 and December 2016. Sensory and taste functions in lingual nerves were preoperatively evaluated using a static two-point discrimination test, an intact superficial pain/tactile sensation test, and a taste discrimination test. They were evaluated again at 12 and at 24 months postoperatively. The abundance ratio of Schwann cells in the excised traumatic neuromas was analyzed with ImageJ software following immunohistochemistry with anti S-100β antibody.
RESULTS:
In early cases (microneurosurgery within 6 months after the injury), recovery ratios of sensory and taste functions were not significantly different at 24 months after microneurosurgery compared with later cases (microneurosurgery more than 6 months after the injury). Meanwhile, the ratio of patients with taste recovery within 12 months after microneurosurgery was significantly decreased in late cases compared with early cases. The abundance ratio of Schwann cells in traumatic neuroma was also significantly lower in later cases.
CONCLUSION
Microneurosurgery more than 6 months after lingual nerve injury did not lead to decreased recovery ratio of sensory and taste functions, but it did lead to prolonged recovery of taste. This delay may be associated with a decrease in the abundance ratio of Schwann cells in traumatic neuromas.
4.Factors Associated With Discharge Destination in Advanced Cancer Patients With Bone Metastasis in a Japanese Hospital.
Katsuhiro HAYASHI ; Tetsutaro YAHATA ; Ryota MURAMOTO ; Norio YAMAMOTO ; Akihiko TAKEUCHI ; Shinji MIWA ; Takashi HIGUCHI ; Kensaku ABE ; Yuta TANIGUCHI ; Hisaki AIBA ; Yoshihiro ARAKI ; Hiroyuki TSUCHIYA
Annals of Rehabilitation Medicine 2018;42(3):477-482
OBJECTIVE: To analyze patient characteristics of cancer rehabilitation and outcomes at our hospital. METHODS: This retrospective study analyzed 580 patients, who underwent cancer rehabilitation at our hospital and rehabilitation outcome after therapy were investigated. The relationship between the initial Barthel index and discharge outcomes was investigated, with a special focus on cancer patients with bone metastasis. The Barthel index and performance status (Eastern Cooperative Oncology Group) before and after rehabilitation were analyzed, and threshold value of home discharge was calculated from a receiver operating characteristic curve (ROC). General criteria for home discharge from our hospital included independence in performing basic activities of daily living such as bathing, feeding, and toileting or availability of home support from a family member/caregiver. RESULTS: The outcomes after rehabilitation among all the patients were as follows: discharge home 59%, death 13%, and others 27%. Statistical differences were observed between the initial and final values of the Barthel index in patients with bone metastasis, who could be discharged home (p=0.012). ROC analysis of the initial Barthel index for predicting home discharge revealed a threshold value of 60, sensitivity of 0.76, and specificity of 0.72. CONCLUSION: The patients with bone metastasis had a lower rate of home discharge and a higher rate of mortality than all the study patients who underwent cancer rehabilitation at our hospital. It is proposed that at the time of initiation of rehabilitation for patients with bone metastasis, an initial Barthel index lower than 60 might predict a worse outcome than home discharge.
Activities of Daily Living
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Asian Continental Ancestry Group*
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Baths
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Humans
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Mortality
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Neoplasm Metastasis*
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Rehabilitation
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Retrospective Studies
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ROC Curve
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Sensitivity and Specificity
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Treatment Outcome