The aim of the study was to measure the cross-sectional area of the psoas major muscle (P-ACSA) in high school athletes and to produce a P-ACSA index independent of body size using an allometric modeling approach to examine the differences in gender and sport specialization. The subjects were 254 female (16.8±0.8 yrs) and 540 male (16.9±0.8 yrs) high-level high school athletes from 17 different sports. Fat-free mass (FFM) was measured by the Bod Pod system (LMI) and P-ACSA was determined by magnetic resonance imaging at the center of the L4-L5 transverse level. Since the power function model fit the data better than a simple linear model in the correlation between FFM and P-ACSA, and the power exponent parameter was almost equal to the theoretically anticipated 2/3 in both genders, the P-ACSA per FFM^2/3 as well as the absolute P-ACSA was calculated. Both of the absolute P-ACSA and P-ACSA per FFM^2/3 were significantly different according to gender and the sport specialization. While volleyball and badminton players and canoeists showed smaller P-ACSA, in accordance with the previous studies on senior sprinters, high school sprinters also showed predominant development of P-ACSA regardless of gender. These results suggested that regular involvement in sprinting activity could affect the size of the psoas major muscle in high school athletes.

Objective: Immunosuppressive therapy for interstitial lung disease (ILD) is often necessary, but the standard regimen for antisynthetase-associated ILD has not been established.Patient: An 80-year-old man was hospitalized for severely progressive dyspnea. Bilateral interstitial shadows occurred 1 month before the event. Serological findings showed that he had antisynthetase-associated ILD, as identified by strong positivity for anti-aminoacyl-transfer RNA synthetase (ARS) antibody, despite no evidence of myositis. He was treated transiently with noninvasive positive pressure ventilation and steroid-pulse therapy followed by 60 mg/day of oral prednisolone. However, his diabetes mellitus was aggravated by corticosteroid therapy; thus, a combination of low-dose steroid and mizoribine (MZB), which has a low risk of aggravating glucose intolerance, was used.Results: The patient’s clinical symptoms and daily life activities have been well persevered as an outpatient and well maintained with 200 mg of MZB and 10 mg of prednisolone for several months without obvious clinical recurrence and without any remarkable steroid- and MZB-related side effects.Conclusion: The use of MZB appeared to suppress the pathophysiology of anti-ARS antibody-associated ILD.

In the present study, we examined the sex-related differences and cross-sectional age-related changes in the cross-sectional area of the psoas major muscle. The cross-sectional area was corrected for fat-free mass (FFM-corrected), which was calculated as the 2/3rd power of the total fat-free mass. A total of 240 adults (114 men, 126 women, age: 20-81 years) were included in the study. The cross-sectional area of the psoas major muscle was measured by 0.2T magnetic resonance imaging (MRI), and the total fat-free mass was measured by air displacement plethysmography. We demonstrated that the FFM-corrected cross-sectional area of the psoas major muscle was greater in males than females across all age groups. Furthermore, we examined the mean FFM-corrected cross-sectional area of the psoas major muscle across different age groups and demonstrated that it decreased with age. Our findings, when combined with previous results, show a peak in the 20s, which declined with age. Our study revealed sex-related differences and cross-sectional age-related changes in the FFM-corrected cross-sectional area of the psoas major muscle. Our findings also suggest that it is important to define reference values and ranges that take into account age- and sex-related differences when assessing the psoas major muscle by FFM-corrected cross-sectional area.

Objective: Most cases of severe metabolic alkalosis have many causes that may result in renal failure and death. Therefore, these should be treated promptly for successful recovery.Patient: A 61-year-old man was hospitalized due to an acute kidney injury (creatinine level of 4.36 mg/dL) after a 3-month history of anorexia and recurrent vomiting. He had been treated for tuberculosis in the past.Results: Blood gas analysis revealed severe metabolic alkalosis with pH=7.66, HCO3=94 mmol/L, and pCO2=82.0 mmHg. Routine biochemical examination revealed severe hypokalemia (K 2.9 mEq/L) that was associated with prolonged QTc interval (0.52 seconds) on the electrocardiogram. Gastrofiberscopic examination also revealed severe stenosis and ulcerated scarring of the gastric pylorus and severe esophagitis. Intravenous hydration and correction of hypokalemia improved renal function and resolved metabolic alkalosis. An investigation that was repeated after 6 days revealed a creatinine level of 1.58 mg/dL, pH=7.47, HCO3=23.4 mmol/L, K=3.6 mEq/L, and QTc of 0.45 seconds. The patient underwent gastrectomy and adenocarcinoma was observed.Conclusion: We described a resolved case of severe metabolic alkalosis and acute kidney injury in a rural medical setting following conservative management.