Tomoko Kutsuzawa

Effects of age on muscle energy metabolism and oxygenation in the forearm muscles

PURPOSE The effects of aging on muscle metabolism and oxygenation have not yet been elucidated. We evaluated the effects of aging on energy metabolism and oxygenation in sedentary healthy subjects by simultaneously measuring 31P-magnetic resonance spectroscopy (MRS) and near-infrared spectroscopy (NIRS). METHODS Nine young (28.1 +/- 5.0 yr) and nine older (61.4 +/- 4.6 yr) healthy subjects were studied. The 31P-MR spectrum was obtained every 15 s during and after hand gripping exercise. Intracellular pH (pHi) and PCr/(PCr+Pi) [PCr: phosphocreatine, Pi: inorganic phosphate] were calculated as an index of energy metabolism. The time constant of the PCr/(PCr+Pi) recovery (tau PCr) was calculated. With NIRS, we evaluated the recovery rates of oxygenated (RHbO2) and deoxygenated hemoglobin (RHb) during the initial 10 s of recovery. RESULTS The PCr/(PCr+Pi) and pHi at rest and at completion of the exercise and tau PCr did not differ between young and older subjects. However, RHbO2 and RHb were significantly slower in older subjects than in young subjects. CONCLUSIONS The results suggest that muscle energy metabolism in the forearm muscle was not affected by aging. The slower RHbO2 and RHb in older subjects suggested impaired O2 supply, which was probably due to impaired peripheral circulation caused by the process of aging.

Acute Effects of Branched-Chain Amino Acid Ingestion on Muscle pH during Exercise in Patients with Chronic Obstructive Pulmonary Disease

The use of 31P-magnetic resonance (MR) spectroscopy (31P-MRS) allows noninvasive measurement of high-energy phosphate compounds such as phosphocreatine (PCr) and adenosine triphosphate (ATP), and the low-energy breakdown product, inorganic phosphate (Pi), in exercising muscle. Ratios of measureable highand low-energy phosphate metabolites (e.g., PCr/Pi or PCr/(PCr+Pi) have been utilized as indices of the overall bioenergetic state of the cell (Sapega et al., 1987). Extracellular Pi does not exist in sufficient quantities to significantly affect 31P-MR spectra (Sapega et al., 1987). Intracellular pH (pHi) can also be measured noninvasively based on the pH-dependent chemical shift of cellular Pi that appears as PCr peaks on 31P-MRS (Sapega et al., 1987; Taylor et al., 1983). A decrease in pHi during exercise suggests lactate accumulation in muscles (Sapega et al., 1987; Taylor et al., 1983).

Branched Chain Amino Acids in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation that is usually progressive. COPD patients have dyspnea, chronic cough and sputum production. In addition, patients with COPD develop systemic features such as body weight (BW) loss, especially muscle wasting, and skeletal muscle dysfunction in addition to pulmonary impairment. Several studies have reported decreased branched-chain amino acids (BCAA) concentration in the plasma and skeletal muscles of depleted patients with COPD. Reduced levels of BCAA may affect muscle energy metabolism during exercise. Some investigations showed that nutritional support with essential amino acids containing high BCAA produced good results in patients with COPD. Nutritional support for pulmonary rehabilitation is needed in COPD patients. Further study is needed to determine prescription nutritional support.

High-dose combination chemotherapy with autologous bone marrow transplantation in lung cancer.

肺小細胞癌3例及び大細胞癌1例に初回治療として, 大量化学療法を自家骨髄移植を併用して施行した. 使用薬剤は小細胞癌がCTX1.49/m2, ApR60mg/m2, ACNU90mg/m2, VCR2mg, 大細胞癌がCTX600mg/m2×2, ADR20mg/m2×2, MTX15mg/m2×2, Procarbazine200mg×10である. 腫瘍縮小効果は全例PRで, 生存期間も標準化学療法と同じであった. 骨髄抑制以外の副作用としては, 発熱を2例に, 問質性肺炎を, 1例に認めた.