1.EVALUATION OF THE MUSCLE OXYGENATION CURVE BY NEAR-INFRARED SPECTROSCOPY (NIRS) DURING RAMP EXERCISE
TSUYOSHI WADAZUMI ; YUTAKA KIMURA ; YOSHITAKE OSHIMA ; TADAYOSHI MIYAMOTO ; SHIGEHIRO TANAKA ; SHIGEO FUJIMOTO
Japanese Journal of Physical Fitness and Sports Medicine 1999;48(1):125-135
A study was conducted to establish a method for quantitative evaluation of both the rate and degree of muscle oxygenation during ramp exercise using Near Infrared Spectroscopy (NIRS), and to determine the relationship of the indices to body composition and physical fitness. The subjects were 13 healthy men. After a warm-up period of 3 min at 20-W, the ramp exercise test was conducted. The exercise consisted of an increasing work rate at a slope of 20 W/min on a cycle ergometer performed until volitional fatigue. The NIRS probe used in the cycling exercise was placed on the vastus lateralis muscle. After 30 min of exercise, calibration was performed by cuff occlusion for 10 min with a pressure of 260 mmHg for quantitative determination of the NIRS curve. The oxygenation curve measured by NIRS during the exercise initially exhibited a linear decrease as the work rate increased. This rate of decrease in oxygenation was indicated by the NIRS slope (%/W) obtained from the calibration curve. In later stages of the exercise, the NIRS curve became flattened with increased work rate. The breaking point between the sloping phase and the flat phase was named the “NIRS Threshold 2, NT 2”. In addition, the rate of decrease in oxygenation at the end of exercise per maximal NIRS decrease obtained from the calibration curve was indicated as the %NIRS fall. The mean NIRS slope and %NIRS fall were 0.3±0.1%/W (range, 0.13 to 0.50%/W) and 29.9±11.8% (range, 12.0 to 50.0%), respectively. NT 2 was observed in 8 of the 13 subjects. The subjects were divided into two groups (NT 2 (+) and NT 2 (-) ) based on the appearance of NT 2. Both the NIRS slope and %NIRS fall in the NT 2 (+) group were significantly higher than those in the NT 2 (-) group. The NIRS slope was significantly correlated with VO2/wt at VT (r=0.73, p<0.05) and wattage at VT (r=0.86, p<0.0001) . The %NIRS fall was significantly correlated with VO2/wt at peak (r=0.80, P<0.001) . The NIRS slope and %NIRS fall were not significantly correlated with body mass index, %fat or thigh circumference.
These findings suggest that the NIRS slope indicates the efficiency of oxygen exchange in muscles activated during incremental exercise, and that the %NIRS fall indicates the ability to utilize Oxy-Hb+Mb against maximal oxygenation capacity in muscles. The NIRS slope and %NIRS fall can therefore be used as indices of muscular limitation during exercise, and as indices of muscular adaptation during exercise.
2.Diarrhea-predominant Irritable Bowel Syndrome-like Symptoms in Patients With Quiescent Crohn’s Disease: Comprehensive Analysis of Clinical Features and Intestinal Environment Including the Gut Microbiome, Organic Acids, and Intestinal Permeability
Toshihiko TOMITA ; Hirokazu FUKUI ; Daisuke MORISHITA ; Ayako MAEDA ; Yutaka MAKIZAKI ; Yoshiki TANAKA ; Hiroshi OHNO ; Tadayuki OSHIMA ; Hiroto MIWA
Journal of Neurogastroenterology and Motility 2023;29(1):102-112
Background/Aims:
Diarrhea-predominant irritable bowel syndrome (IBS-D)-like symptoms frequently occur in patients with quiescent Crohn’s disease (CD). To investigate the factors underlying IBS-D-like symptoms in patients with quiescent CD, we performed a comprehensive analysis of the clinical features and intestinal environment in those patients.
Methods:
We performed a prospective observational study of 27 patients with quiescent CD (CD activity index [CDAI] ≤ 150; C-reactive protein ≤ 0.3 mg/dL). The presence and severity of IBS-D-like symptoms, health-related quality of life, disease-specific quality of life, andstatus of depression and anxiety were evaluated. The level of intestinal permeability, fecal calprotectin and organic acids and the profiles of gut microbiome were analyzed.
Results:
Twelve of the 27 patients with quiescent CD (44.4%) had IBS-like symptoms, and these patients showed a significantly higher CDAI, IBS severity index and anxiety score than those without. The inflammatory bowel disease questionnaire score was significantly lower in the patients with IBS-D-like symptoms. There were no significant differences in small intestinal/colonic permeability or the levels of organic acids between the patients with and without IBS-D-like symptoms. Fusicatenibacter was significantly less abundant in the patients with IBS-D-like symptoms whereas their fecal calprotectin level was significantly higher (384.8 ± 310.6 mg/kg) than in patients without (161.0 ± 251.0 mg/kg). The receiver operating characteristic curve constructed to predict IBS-D-like symptoms in patients with quiescent CD using the fecal calprotectin level (cutoff, 125 mg/kg) showed a sensitivity and specificity of 73.3% and 91.7%, respectively.
Conclusion
Minimal inflammation is closely associated with the development of IBS-D-like symptoms in patients with quiescent CD.
3.Long-term treatment results of pembrolizumab monotherapy: reconsideration of immune checkpoint inhibitor monotherapy
Takanobu SASAKI ; Takafumi SUGAWARA ; Toshiharu TABATA ; Naoya ISHIBASHI ; Hideki MITOMO ; Yutaka OSHIMA ; Ryo NONOMURA
Journal of Rural Medicine 2024;19(4):273-278
Objective: The extended outcomes of the KEYNOTE-024 study demonstrated a favorable 5-year overall survival (OS) rate of 31.9%. The present study investigated the outcomes of pembrolizumab monotherapy for advanced or recurrent non-small cell lung cancer (NSCLC) at our institution.Patient: The long-term outcomes of 102 patients with advanced or recurrent NSCLC treated with pembrolizumab monotherapy between March 2017 and December 2022 were retrospectively assessed.Results: This study included a total of 102 patients [mean age: 72 ± 9.6 years (range: 41–91 years), male/female=77/25; performance status (PS; 0, 1, 2, 3, 4)=49/38/15/0/0; smokers=91 (89%), non-squamous cell carcinoma/squamous cell carcinoma=66/36, PD-L1 tumor proportion score (TPS) ≥50%/1–49%=80/22, positive for EGFR mutation=5, advanced/postoperative recurrence=51/51, treatment line: first/second or later=81/21, treatment courses: median 8 (range: 1–39), objective response rate/disease control rate=44%/55%, immune-related adverse events (irAEs): 47, 5-year OS=34%]. On univariate analysis, PS, PD-L1 TPS, and irAEs were significant prognostic factors. On multivariate analysis, histology, PD-L1 TPS, and irAEs were significant prognostic factors.Conclusion: Pembrolizumab monotherapy demonstrated promising treatment outcomes for advanced or recurrent NSCLC, as evidenced by the significant association of PD-L1 TPS with irAEs and prognosis, suggesting its potential as a beneficial therapeutic option.