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1.
Materials (Basel) ; 17(15)2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39124335

RESUMEN

Bioabsorbable materials have a wide range of applications, such as scaffolds for regenerative medicine and cell transplantation therapy and carriers for drug delivery systems. Therefore, although many researchers are conducting their research and development, few of them have been used in clinical practice. In addition, existing bioabsorbable materials cannot bind to the body's tissues. If bioabsorbable materials with an adhesive ability to biological tissues can be made, they can ensure the mixture remains fixed to the affected area when mixed with artificial bone or other materials. In addition, if the filling material in the bone defect is soft and uncured, resorption is rapid, which is advantageous for bone regeneration. In this paper, the development and process of a new bioabsorbable material "Phosphorylated pullulan" and its capability as a bone replacement material were demonstrated. Phosphorylated pullulan, which was developed based on the tooth adhesion theory, is the only bioabsorbable material able to adhere to bone and teeth. The phosphorylated pullulan and ß-TCP mixture is a non-hardening putty. It is useful as a new resorbable bone replacement material with an adhesive ability for bone defects around implants.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38913845

RESUMEN

This study developed a highly sensitive microbiological method utilizing a novel microtiter plate to screen 10 sulfonamides in chicken muscles, eggs, and prawns. This plate was fabricated from agar incorporating trimethoprim and spread with Bacillus megaterium. After residue detection by bioassay, the same test solutions were analyzed by LC-MS/MS for accurate identification and quantification. It also proved eco-friendly compared to using other quantitative methods. The residual drugs were extracted with McIlvaine buffer and purified using an Oasis® MCX cartridge. A triethylamine/methanol/water (0.5:75:24.5, v/v/v) mixture was used as the eluate. The obtained LOD values of the bioassay ranged from 5 to 25 µg kg-1 allowing the detection of the target drugs at the MRLs established in Japan. Adhering to ISO/IEC 17025 standards, the performance of the bioassay was evaluated. Based on the inhibition zone size in bioassay results, quality control yielded a Z score within ±2, indicating reasonable control over the screening process. Proficiency testing of a chicken muscle sample spiked with sulfadimidine demonstrated the inhibition zone detection of the bioassay and quantified value alignment of LC-MS/MS with reference values. In a surveillance study of 91 samples, sulfamethoxazole was detected in one prawn sample.


Asunto(s)
Pollos , Contaminación de Alimentos , Sulfonamidas , Espectrometría de Masas en Tándem , Animales , Sulfonamidas/análisis , Sulfonamidas/química , Contaminación de Alimentos/análisis , Cromatografía Liquida , Huevos/análisis , Análisis de los Alimentos , Residuos de Medicamentos/análisis , Residuos de Medicamentos/química , Carne/análisis , Cromatografía Líquida con Espectrometría de Masas
3.
Front Bioeng Biotechnol ; 12: 1378039, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38840668

RESUMEN

Various implant surface treatment methods have been developed to achieve good osseointegration in implant treatment. However, some cases remain impossible to treat with implants because osseointegration is not obtained after implantation, and the implants fail. Thus, this study focused on phosphorylated pullulan because of its adhesiveness to titanium (Ti) and bone, high biocompatibility, and early replacement with bone. In this study, the response of bone-related cells to phosphorylated pullulan was evaluated to develop a new surface treatment method. Saos-2 (human osteosarcoma-derived osteoblast-like cells), MC3T3-E1 (mouse calvaria-derived osteoblast-like cells), and RAW264.7 (mouse macrophage-like cells) were used. In evaluating cellular responses, phosphorylated pullulan was added to the culture medium, and cell proliferation and calcification induction tests were performed. The proliferation and calcification of cells on the surface of Ti disks coated with phosphorylated pullulan were also evaluated. In addition, bone morphogenetic protein-2 (BMP-2), an osteogenic factor, was used to evaluate the role of phosphorylated pullulan as a drug carrier in inducing calcification on Ti disks. Phosphorylated pullulan tended to promote the proliferation of osteoblast-like cells and the formation of calcification on Ti disks coated with phosphorylated pullulan. Ti disks coated with phosphorylated pullulan loaded with BMP-2 enhanced calcification. Phosphorylated pullulan inhibited osteoclast-like cell formation. These results are due to the properties of phosphorylated pullulan, such as adhesiveness to titanium and drug-loading function. Therefore, phosphorylated pullulan effectively promotes bone regeneration when coated on titanium implants and is useful for developing a new surface treatment method.

4.
Health Sci Rep ; 7(6): e2175, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38895550

RESUMEN

Background and Aims: Mild cognitive impairment (MCI) is a widespread condition in older individuals, posing significant risk of dementia. However, limited research has been conducted to explore effective interventions and clarify their impact at the neural level. Therefore, this study aimed to investigate the effects of computerized cognitive training (CCT) and explore the associated neural mechanisms in preventing dementia in older individuals with MCI, with a view to inform future intervention efforts. Methods: We reviewed the effects of CCT on biomarker outcomes in older adults with MCI. The search was conducted for studies published between 2010 and May 10, 2023, using three search engines: PubMed, Scopus, and Cumulative Index to Nursing and Allied Health Literature. The inclusion criteria were as follows: studies that involved participants diagnosed with MCI, included CCT, included quantitative assessment of biomarker results, and conducted randomized controlled trials. Results: Sixteen studies that used biomarkers, including magnetic resonance imaging, electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and blood or salivary biomarkers, were extracted. The results showed that CCT caused changes in structure and function within the main brain network, including the default mode network, and decreased both theta rhythm activity on EEG and prefrontal activity on fNIRS, with improvement in cognitive function. Furthermore, CCT combined with physical exercise showed more significant structural and functional changes in extensive brain regions compared with CCT alone. Virtual reality-based cognitive training improved not only executive function but also instrumental activities of daily living. Conclusion: CCT causes functional and structural changes in extensive brain regions and improves cognitive function in older adults with MCI. Our findings highlight the potential of individualized intervention methods and biomarker assessment according to the specific causes of MCI. Future research should aim to optimize these personalized therapeutic strategies to maximize the benefits of CCT in older adults with MCI.

6.
Forensic Toxicol ; 42(2): 163-171, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38519777

RESUMEN

PURPOSE: The presence of cereulide, an emetic toxin produced by Bacillus cereus, in fried rice samples is critical evidence of food poisoning even in situations where B. cereus could not be detected. This study aims to develop a screening method for analyzing cereulide in fried rice using the QuEChERS procedure and liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: Cereulide was identified and quantified in fried rice samples using the QuEChERS extraction method and LC-MS/MS. The accuracies of the methods were determined by analyzing fortified blank samples at two concentrations (10 and 50 µg/kg) conducted on three samples daily for five days. RESULTS: The QuEChERS procedure removed matrix compounds from fried rice. Characteristic MS/MS spectra enabled the identification of cereulide. As the matrix effects in seven fried rice samples were within ± 6%, an external solvent calibration curve could be used for quantification. This method exhibited good accuracy ranging from 88 to 89%. The relative standard deviations for both repeatability and intra-laboratory reproducibility were < 4%. These standard deviations satisfied the criteria of the Japanese validation guidelines for residues (MHLW 2010, Director Notice, Syoku-An No. 1224-1). The limit of quantification was 2 µg/kg. The applicability of this method was confirmed using the analysis of cereulide in fried rice samples incubated with emetic Bacillus cereus. CONCLUSIONS: The QuEChERS extraction procedure described herein showed substantial promise as a reliable screening tool for cereulide in fried rice sample.


Asunto(s)
Depsipéptidos , Oryza , Espectrometría de Masas en Tándem , Oryza/química , Oryza/microbiología , Espectrometría de Masas en Tándem/métodos , Depsipéptidos/análisis , Cromatografía Liquida/métodos , Reproducibilidad de los Resultados , Contaminación de Alimentos/análisis , Bacillus cereus/aislamiento & purificación , Toxinas Bacterianas/análisis , Toxinas Bacterianas/aislamiento & purificación
7.
Cancers (Basel) ; 16(4)2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38398113

RESUMEN

Acute lymphoblastic leukemia (ALL) is the most common disease in pediatric oncology. The history of developmental therapeutics for ALL began in the 1960s with the repetition of "unreliable" medical interventions against this lethal disease. By the 1990s, the development of multi-agent chemotherapy and various types of supportive care rendered ALL treatable. Highly sophisticated, molecular, diagnostic techniques have enabled highly accurate prediction of the relapse risk, and the application of risk-adapted treatments has increased the survival rate in the standard-risk group to nearly 100% in most European nations and North America. Incorporation of state-of-the-art, molecularly targeted agents and novel treatments, including cell and immunotherapy, is further improving outcomes even in the high-risk group. On the other hand, the financial burden of treating children with ALL has increased, imperiling the availability of these diagnostic and treatment strategies to patients in low- and middle-income countries (LMICs). The fundamental treatment strategy, consisting of corticosteroid and classical cytotoxic therapy, has achieved fairly good outcomes and should be feasible in LMICs as well. The present review will discuss the history of developmental therapeutics for childhood ALL in various countries through an extensive literature review with the aim of proposing a model for a treatment backbone for pediatric ALL. The discussion will hopefully benefit LMICs and be useful as a base for future clinical trials of novel treatments.

8.
Artículo en Inglés | MEDLINE | ID: mdl-38252707

RESUMEN

The simultaneous determination of five carbapenems (biapenem, doripenem, ertapenem, imipenem, and meropenem) in raw and pasteurised bovine milk samples using LC-MS/MS was achieved and validated. Chromatographic separation was conducted on an InertSustain® AQ-C18 column using 0.1% formic acid in water and acetonitrile as the mobile phase. Target compounds were extracted using acetonitrile/water (20:80, v/v). After the removal of lipids with acetonitrile-saturated hexane, the dissolved protein was denatured with acetic acid. A portion of the supernatant was passed through an Oasis® PRiME HLB cartridge to remove the matrix. This novel method was validated in accordance with the Japanese validation guidelines and exhibited good trueness, ranging from 86.3% to 96.2%, using matrix-matched calibration curves. The relative standard deviation of repeatability ranged from 1.0% to 6.3%, and that of within-laboratory reproducibility ranged from 1.6% to 7.1%. The limit of quantification was 1.0 µg kg-1 for all analytes. None of the 60 milk samples commercially available in Tokyo contained any analytes. This novel method exhibited high-quality performance and can easily be implemented for the routine monitoring of carbapenems, which are highly polar antibiotics in milk.


Asunto(s)
Antibacterianos , Carbapenémicos , Animales , Antibacterianos/análisis , Carbapenémicos/análisis , Cromatografía Liquida/métodos , Cromatografía Líquida con Espectrometría de Masas , Espectrometría de Masas en Tándem/métodos , Leche/química , Reproducibilidad de los Resultados , Acetonitrilos , Agua/análisis , Cromatografía Líquida de Alta Presión/métodos
9.
JACC Clin Electrophysiol ; 10(1): 43-55, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37855769

RESUMEN

BACKGROUND: Ventricular tachycardia (VT) associated with primary cardiac tumors (PCTs) originating from the ventricles is rare, but lethal, in young patients. OBJECTIVES: This study aimed to clarify the mechanisms underlying primary cardiac tumor-related ventricular tachycardia (PCT-VT) and establish a therapeutic strategy for this form of VT. METHODS: Among 67 patients who underwent surgery for VT at our institute between 1981 and 2020, 4 patients aged 1 to 34 years, including 3 males, showed PCT-VT (fibroma, 2; lipoma, 1; and hamartoma, 1), which was investigated using a combination of intraoperative electroanatomical mapping and histopathological studies. RESULTS: All 4 patients developed electrical storms of sustained VTs refractory to multiple drugs and repetitive endocardial ablations. The VT mechanism was re-entry, and intraoperative electroanatomical mapping showed a centrifugal activation pattern originating from the border between the tumor and healthy myocardium, where fractionated potentials were detected during sinus rhythm. Histopathological studies of serial sections of specimens acquired from these areas revealed tumor infiltration into the surrounding myocardium with cell disorganization, exhibiting myocardial disarray. Several myocardia entrapped in the tumor edges contributed to the development and sustainment of re-entrant VT activation. In the 2 patients in whom complete resection was unfeasible, encircling cryoablation to entirely isolate the unresectable tumor was effective in suppressing VT occurrence. CONCLUSIONS: The mechanism underlying PCT-VT involves re-entry localized at the tumor edges. Myocardial disarray associated with tumor infiltration is a substrate for this form of VT. Cryoablation along the border between the tumor and myocardium is a promising therapeutic option for unresectable PCT-VT.


Asunto(s)
Neoplasias Cardíacas , Taquicardia Ventricular , Masculino , Humanos , Taquicardia Ventricular/etiología , Taquicardia Ventricular/cirugía , Ventrículos Cardíacos , Miocardio , Neoplasias Cardíacas/complicaciones , Neoplasias Cardíacas/cirugía , Endocardio
10.
Psychiatr Res Clin Pract ; 5(4): 126-130, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38077275

RESUMEN

Objective: Identifying factors associated with poor outcomes in patients with delirium is important for predicting prognosis. This retrospective study developed an easy and objective cognitive function measurement scale that can predict the prognosis and mortality related to delirium. Methods: Fifty-five patients aged ≥65 years and diagnosed with delirium were included. Objective data regarding attention and orientation related to time and place were extracted from their medical records during the first consultation, and in total, six points were evaluated. The patients were categorized into high and low cognitive function (LCF) groups. The severity at the first visit and 1-week post-treatment was evaluated using the Clinical Global Impressions-Severity scale. Outcomes (survival or death) at 6 months from the initial visit were evaluated by reviewing medical records. Results: Although the Clinical Global Impressions-Severity score at the first visit was not significantly different between the two groups, 1 week after treatment, it was significantly lower in the high cognitive function (HCF) group than in the LCF group. Regarding the outcome (survival or death) after 6 months, the LCF group had significantly higher mortality than the HCF group. A multivariate logistic regression analysis revealed the same result (OR = 17.049, 95% CI = 2.415-120.373, p = 0.004). Conclusion: A simple cognitive assessment of attention and orientation may help predict unfavorable outcomes, including mortality, in patients with delirium.

11.
Int J Cardiol Heart Vasc ; 49: 101297, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38035257

RESUMEN

Introduction: Although catheter ablation (CA) of tachycardia-bradycardia syndrome (TBS) in patients with atrial fibrillation (AF) is considered to be an effective treatment strategy, pacemaker implantations (PMIs) are often required even after a successful CA. This study aimed to elucidate the clinical predictors of a PMI after CA. Methods: From 2011 to 2020, 103 consecutive patients diagnosed with TBS were retrospectively enrolled in the study. Among the 103 patients, 54 underwent a PMI and 49 CA of AF. During 47.4 ± 35.4 months after 1.4 ± 0.6 CA sessions, 37 (75.5%) of 49 patients were free from atrial arrhythmia recurrences. PMIs were performed in 11 patients (PMI group) and the remaining 38 did not receive a PMI (non-PMI group). Results: When comparing the PMI and non-PMI groups, there were no differences in the basic mean heart rate (P = 0.36), maximum pauses detected by 24-hour Holter-monitoring (P = 0.61), and other clinical parameters between the two groups while the right atrial area index was larger (42.1 ± 24.0 vs. 21.8 ± 8.4 cm2/m2 P = 0.002) in the PMI group than non-PMI group. The ROC curve analysis showed that the optimal cutoff point of the ratio of the right atrial area index to the left atrial area index for predicting a PMI following CA was 0.812 (Sensitivity 72.7%, specificity 71.1%, positive predictive value 42.1%, negative predictive value 90.0%, diagnostic accuracy 71.4%, AUC = 0.81). Conclusion: Right atrial enlargement prior to CA was considered to be one of the risk factors for a PMI after CA of AF.

12.
J Orthop Case Rep ; 13(9): 38-41, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37753124

RESUMEN

Introduction: Remote cerebellar hemorrhage (RCH) has been reported as a serious complication of spine surgery and is considered to be caused by dural injury. However, we have experienced a case in which intracranial hemorrhage occurred immediately after lumbar spine surgery without dural tear. There were no reports of RCH in spinal surgery without dural injury as far as we could find. Case Report: We described a rare presentation of an 80-year-old male who suffered a loss of consciousness after lumbar surgery. He was diagnosed with impaired consciousness due to chronic and acute intracranial hemorrhage. He went through two hematoma removal surgeries and his consciousness improved. Conclusion: RCH can occur in spinal surgery in patients with predicted cerebrovascular fragility, even in the absence of dural injury. Pre-operative imaging evaluation could be useful in assessing cerebrovascular fragility.

13.
Knee ; 44: 189-193, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37672910

RESUMEN

BACKGROUND: Rotating-platform posterior-stabilized total knee arthroplasty (PS-TKA) has become a commonly used procedure. It has the potential risk of causing mobile-bearing spinout. In our study, we investigated the factors affecting the bearing thickness when performing rotating-platform PS-TKA. METHODS: This single-arm, prospective, single-hospital cohort study included 100 consecutive patients who underwent rotating-platform PS-TKA between September 2020 and August 2022. We examined the relationship between bearing thickness and several patient characteristics. RESULTS: The results of the univariate analysis showed that the bearing thickness was significantly associated with weight (risk ratio = 3.4; 95% confidence interval (CI) = 1.1-11.0; P = 0.016) and implant size of the tibia (risk ratio = 3.4; 95% CI = 1.0-11.5; P = 0.030). We performed multivariate analysis regarding the weight and implant size of the tibia. Neither the weight nor the implant size of the tibia was significantly different from the bearing thickness in the multivariate analysis. CONCLUSIONS: In rotating-platform PS-TKA, body weight and tibia size may affect the bearing thickness. Weight >60 kg and tibial implant size >67 cm may be risk factors for bearing thickening. Therefore, the surgery can be performed better if these risk factors are considered.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Prótesis de la Rodilla , Osteoartritis de la Rodilla , Humanos , Artroplastia de Reemplazo de Rodilla/métodos , Prótesis de la Rodilla/efectos adversos , Estudios de Cohortes , Estudios Prospectivos , Rango del Movimiento Articular , Diseño de Prótesis , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/cirugía , Osteoartritis de la Rodilla/cirugía
14.
Pediatr Infect Dis J ; 42(12): 1041-1044, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37725804

RESUMEN

BACKGROUND: Yersinia infection is known to present with Kawasaki disease (KD)-like symptoms although differentiating the 2 has been a challenge. The present study aimed to describe the clinical characteristics and prevalence of Yersinia infection presenting with KD-like symptoms. METHODS: The present, prospective, multicenter study enrolled patients who received a diagnosis of KD between January 2021 and January 2022 at 2 hospitals in Tokyo. Stool samples were collected within 3 days of the start of KD treatment, and cultures were performed for Yersinia . Clinical history and symptoms suggestive of Yersinia infection were also evaluated. RESULTS: During the study period, 141 KD patients were screened and 117 patients with evaluable stool samples were registered. Only 1 patient was positive for Yersinia pseudotuberculosis , which was detected from both stool and blood cultures. The patient was refractory to KD treatment but improved after initiation of appropriate antibiotic therapy. CONCLUSIONS: Routine screening for Yersinia is not appropriate for patients with KD and should be limited to certain patients in high-risk areas and those who are refractory to the standard KD treatment.


Asunto(s)
Síndrome Mucocutáneo Linfonodular , Yersiniosis , Infecciones por Yersinia pseudotuberculosis , Yersinia pseudotuberculosis , Humanos , Síndrome Mucocutáneo Linfonodular/complicaciones , Síndrome Mucocutáneo Linfonodular/diagnóstico , Síndrome Mucocutáneo Linfonodular/epidemiología , Infecciones por Yersinia pseudotuberculosis/complicaciones , Infecciones por Yersinia pseudotuberculosis/diagnóstico , Infecciones por Yersinia pseudotuberculosis/epidemiología , Estudios Prospectivos , Yersiniosis/complicaciones , Yersiniosis/epidemiología
17.
Int Heart J ; 64(2): 164-171, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37005312

RESUMEN

Patients with acute myocardial infarction (AMI) triaged as life-threatening are transferred to our emergency medical care center (EMCC). However, data on these patients remain limited. We aimed to compare the characteristics and AMI prognosis of patients transferred to our EMCC with those transferred to our cardiovascular intensive care unit (CICU) using whole and propensity-matched cohorts.We analyzed the data of 256 consecutive AMI patients transferred from the scene to our hospital by ambulance between 2014 and 2017. The EMCC and CICU groups comprised 77 and 179 patients, respectively. There were no significant between-group age or sex differences. Patients in the EMCC group had more disease severity score and had the left main trunk identified as the culprit more frequently (12% versus 0.6%, P < 0.001) than those in the CICU group; however, the number of patients with multiple culprit vessels did not differ. The EMCC group had a longer door-to-reperfusion time (75 [60, 109] minutes versus 60 [40, 86] minutes, P< 0.001) and a higher in-hospital mortality (19% versus 4.5%, P < 0.001), especially from non-cardiac causes (10% versus 0.6%, P < 0.001), than the CICU group. However, peak myocardial creatine phosphokinase did not significantly differ between the groups. The EMCC group had a significantly higher 1-year post-discharge mortality than the CICU group (log-rank, P = 0.032); this trend was maintained after propensity score matching, although the difference was not statistically significant (log-rank, P = 0.094).AMI patients transferred to the EMCC exhibited more severe disease and worse overall in-hospital and non-cardiac mortality than those transferred to the CICU.


Asunto(s)
Cuidados Posteriores , Infarto del Miocardio , Humanos , Masculino , Femenino , Alta del Paciente , Infarto del Miocardio/complicaciones , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/epidemiología , Pronóstico , Hospitales , Mortalidad Hospitalaria , Estudios Retrospectivos
18.
Shokuhin Eiseigaku Zasshi ; 64(1): 53-60, 2023.
Artículo en Japonés | MEDLINE | ID: mdl-36858592

RESUMEN

A method for the rapid analysis of multiclass residual veterinary drugs in poultry muscle, egg, and raw milk was validated in accordance with Japanese guidelines. Using LC-MS/MS, 20 veterinary drugs, including sulfonamides, coccidiostats, and macrolides were analyzed in one injection. Analytes were extracted from the samples with acetonitrile and then dehydrated and salted out using magnesium sulfate, trisodium citrate, and sodium chloride. This method was assessed by performing recovery tests of chicken muscle, duck muscle, egg, and raw milk spiked with 20 new target analytes at concentrations of 10 and 100 µg/kg. According to this method, 17 out of 20 target analytes satisfied the guideline criteria in chicken muscle and duck muscle, and all 20 target analytes met the criteria in egg and raw milk. The limit of quantification was less than MRLs for all analytes. Residues were detected in 4 out of 99 samples and analyzed using the validated method, finding that the levels of all residues were lower than the limits of quantification. These results suggest that continuous monitoring for a new trend of veterinary drugs is necessary.


Asunto(s)
Ganado , Drogas Veterinarias , Animales , Cromatografía Liquida , Espectrometría de Masas en Tándem , Antibacterianos , Pollos
20.
Forensic Toxicol ; 41(2): 249-259, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36773219

RESUMEN

PURPOSE: Detection of Clostridium perfringens enterotoxin (CPE) in human stool is critical evidence of food poisoning. However, processing patient-derived samples is difficult and very few methods exist to confirm the presence of CPE. In this study, a technique was developed using proteomic analysis to identify and quantify CPE in artificial gut fluid as an alternative. METHODS: The standard CPE was spiked into artificial gut fluids, and effective methods were developed by employing both a stable isotope-labelled internal standard peptide and liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: Proteotypic peptide EILDLAAATER formed by tryptic digestion was selected for quantitation of CPE. The peptide was identified using product ion spectra. Although the nontoxic peptides originating from CPE showed very low detectability in extraction and tryptic digestion, they could be detected with sufficient sensitivity using the method we developed. Based on a spiked recovery test at two concentrations (50 and 200 µg/kg), the recovery values were 85 and 78%, respectively. The relative standard deviations of repeatability and within-laboratory reproducibility were less than 8 and 11%, respectively. These standard deviations satisfied the criteria of the Japanese validation guidelines for residues (MHLW 2010, Director Notice, Syoku-An No. 1224-1). The limit of quantification (LOQ) was estimated to be 50 µg/kg. The combination of the product ion spectra and relative ion ratio supported CPE identification at the LOQ level. CONCLUSIONS: To the best of our knowledge, this is the first report of proteomic analysis of CPE using LC-MS/MS. The method would greatly help in assessing CPE reliably.


Asunto(s)
Proteómica , Espectrometría de Masas en Tándem , Humanos , Cromatografía Liquida/métodos , Espectrometría de Masas en Tándem/métodos , Reproducibilidad de los Resultados , Péptidos/análisis , Isótopos
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