Activation of Ca2+/calmodulin-dependent protein kinase II by stimulation with bradykinin in neuroblastoma x glioma hybrid NG108-15 cells.

To elucidate the mechanisms of the intracellular signal transduction elicited with bradykinin in NG108-15 neuroblastoma x glioma hybrid cells, we examined the activation of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) by bradykinin stimulation. When the extract of NG108-15 cells was immunoprecipitated with the affinity-purified antibody to brain CaM kinase II, a 50-kDa protein in the immunoprecipitate mainly became autophosphorylated in a Ca2+/calmodulin-dependent manner. The results suggest that the 50-kDa protein is the subunit of CaM kinase II in NG108-15 cells. The Ca2+/calmodulin-independent activity (autonomous activity) of the enzyme increased twice within 10 s by stimulation with 1 microM bradykinin in the cells. The increase in the autonomous activity of the enzyme had two phases: the transient early-peak phase and the long late-plateau phase. The former was abolished by the pretreatment of the cells with 10 mM caffeine or 20 microM BAPTA-AM, and the latter was abolished by the removal of the extracellular Ca2+ with 1 mM EGTA or by the pretreatment with 1 microM nifedipine. Stimulation of 32P-labeled NG108-15 cells with 1 microM bradykinin increased the autophosphorylation of CaM kinase II and this increase was abolished by pretreatment with caffeine or BAPTA-AM. These results suggest that CaM kinase II is activated via the inositol phospholipid signaling pathway induced with bradykinin in NG108-15 cells.     

Late Effects of Childhood Acute Leukemia and Its Treatment

Late effects of childhood acute leukemia and its treatment were studied in 766 patients (684 ALL, 73 ANLL, and 9 others) in Japan who had remained in remission for more than 1 year after their first complete remission. Delayed adverse sequelae involve a wide variety of organs and their functions. Short stature was present in 2.61%, obesity in 3.79%, abnormalities of growth hormone secretion in 1.5%, delayed secondary sex characteristics in 1.5% of males and 0.6% of females, motor disturbances in 1.17%, sensory disturbances in 0.91%, intellectual and learning disabilities in 2.48%, abnormal findings in routine neurologic examinations in 1.31%, EEG abnormalities in 4.30%, brain CT abnormalities in 5.09% and cardiac dysfunction in 1.07%. Various other disorders were seen in 20 patients. Many of these delayed adverse sequelae are caused by or related to central nervous system prophylaxis and systemic combination chemotherapy. The results suggest that it is needed to improve therapeutic methods through the stratification of patients by risk factors and detailed analysis of prognostic factors. Moreover it is important to render medical and psychosocial support to long-term survivors of childhood leukemia through interactions between the patient, parents and medical staff.     

Clinical significance of serum cardiac myosin light chain I in patients with Duchenne muscular dystrophy]

The cardiac myosin light chain I (LCI) is one of the cardiac muscle structural proteins. A sensitive immunoradiometric assay kit for LCI by using LCI monoclonal antibodies is developed. We estimated LCI in the patients with Duchenne muscular dystrophy (DMD) and Kugelberg-Welander disease (KW). The results suggested that LCI has close relationships with the functional disturbances of skeletal muscles, especially disturbances of pulmonary ventilation. Therefore we studied properties and localizations of LCI in the skeletal muscles by Western blotting and immunohistochemical methods. In Western blotting method LCI monoclonal antibodies have a band of 27 KD proteins of skeletal muscles. LCI has also found to be localized in type 1 fibers in frozen sections of biopsied of human skeletal muscles. LCI was measured from 47 patients with DMD and 8 patients with KW. The average serum LCI levels in the patients with DMD were 11.79 ng/dl and its levels in the patients with KW were in the normal range (under 2.5 ng/dl). Among 12 patients receiving negative pressure chest respirator, the levels of LCI were also under 2.5 ng/dl. Serum LCI decreased with increasing age and reduced physical activity. The levels of LCI has obvious positive correlations with CK and myoglobin. These results suggested that the measurements of serum LCI are useful as one of the markers of disease severity and the determination of suitable time of using respirator.     

A double-blind dose-ranging study of risedronate in Japanese patients with osteoporosis (a study by the Risedronate Late Phase II Research Group)

To determine the clinical recommended dosage regimen of risedronate for the treatment of involutional osteoporosis in Japanese patients, dose-response relationships for the efficacy and safety of this drug were investigated using a multi-center, randomized, double-blind, parallel group comparative design with four dose levels of risedronate (placebo, 1 mg, 2.5 mg and 5 mg per day). A total of 211 patients diagnosed with involutional osteoporosis according to the criteria proposed by the Japanese Society for Bone and Mineral Research were randomized and received one of the four doses once daily for 36 weeks. All patients were supplemented with 200 mg of calcium daily in the form of calcium lactate. The primary efficacy endpoint was the percent change in bone mineral density of the lumbar spine (L2-L4 BMD) determined by dual-energy X-ray absorptiometry (DXA) from baseline to the time of final evaluation. Changes in biochemical markers of bone turnover and safety profile were also compared. Percent changes in L2-L4 BMD at final evaluation in the placebo, and 1-, 2.5-, and 5-mg risedronate groups were 0.79+/-5.30, 2.71+/-4.93, 5.29+/-3.96, and 5.15+/-4.25% (mean+/-SD), respectively. A linear dose-response relationship was obtained up to a dose of 2.5 mg, whereas no further increase in BMD was observed at 5 mg. The decrease in bone turnover markers, including N-terminal osteocalcin, phosphorus, and urinary deoxypyridinoline, also showed a linear dose-response relationship up to a dose of 2.5 mg. Alkaline phosphatase level decreased linearly up to a dose of 5 mg. Risedronate was well tolerated in this 36-week study with 1- to 5-mg doses. Neither the overall incidence of adverse events nor the percentage of patients without problem in overall safety assessment differed significantly among the dose groups including the placebo group. Based on these results, a once-daily dose of 2.5 mg of risedronate, which is half that used in Caucasians, is recommended for the treatment of involutional osteoporosis in Japanese patients.     

Effect of local blood circulation and absolute torque on muscle endurance at two different knee-joint angles in humans

The effects of the local blood circulation and absolute torque on muscle endurance at different knee-joint angles were determined. The rate of muscle deoxygenation (using near-infrared spectroscopy), and the rate of muscle fatigue (using the slope of integrated electromyography, iEMG) were evaluated concurrently. Nine healthy subjects performed submaximal (50% maximal voluntary contraction, MVC) static knee extension at 50° (extended position, EXT) and 90° (flexed position, FLEX) joint angles until the target torque could no longer be maintained: that time was measured as the endurance time. They exercised with the circulation occluded (OCCL), and without (FREE) to study the possible effects of the local circulation. Although MVC torque was independent of joint angle [mean (SD) FLEX 250.6 (51.7) N·m and EXT 246.5 (46.6) N·m], significantly shorter (P<0.01) endurance time in FLEX [FREE 71.1 (10) s and OCCL 63.1 (8.8) s] than at EXT [FREE 115.3 (30) s and OCCL 106.7 (29.1) s] were obtained in both circulatory conditions. The iEMG-time slope was significantly greater in FLEX at the proximal and distal portion (P<0.05) in both circulatory conditions. Muscle deoxygenation rate in OCCL was significantly greater (P<0.05) at FLEX [20.8 (8.0)%] than EXT [10.9 (4.0)%]. The results would suggest that different knee-joint angle affects muscle endurance even if the local circulation is controlled. Circulatory disturbance would further reduce muscle endurance in EXT, but not in FLEX. Because of the greater muscle internal force in FLEX, local blood flow might be already limited even with a free circulation. The greater muscle deoxygenation and muscle fatigability would be related to the shorter muscle endurance in FLEX. Electronic Publication     

A comparison of three bioelectrical impedance analyses for predicting lean body mass in a population with a large difference in muscularity

This study tested the hypothesis that, as compared to whole-body bioelectrical impedance (BI) analysis, segmental BI analysis can estimate lean body mass (LBM) more accurately in a population with a large difference in muscularity. In addition to whole-body BI, which determines impedance (Z) between the wrist and ankle, two segmental BI analyses which determine the Z value of every body segment in each of (1) the arms, legs and trunk (distal BI) and (2) the upper arms, upper legs and trunk (proximal BI) were applied to a group of 125 male athletes and 75 non-athletes. The subjects were divided into validation and cross-validation groups. Simple and multiple regression analyses were applied to (length)²/Z (BI index) values for the whole-body and each body segment, to develop the prediction equations of LBM measured using air-displacement plethysmography. In the validation group, the SE of estimation was similar in the whole-body (3.4 kg, 5.4%), distal (3.4 kg, 5.5%) and proximal BI (3.3 kg, 5.2%) analyses. However, the whole-body and distal BI analyses produced systematical errors in the estimates of LBM. Moreover, the residuals in the two methods significantly (P<0.05) correlated with the ratios of BI indices of the upper arms and upper legs to those of the arms and legs, respectively, calculated as variables approximating the relative development of lean tissues at the proximal area of limbs. On the other hand, the proximal BI analysis was validated and cross-validated. Thus, the accuracy of estimating LBM was similar in the whole-body and the two segmental BI analyses. However, the prediction equations derived from the use of the whole-body BI index and a combination of the arms, legs and trunk BI indices produced a systematical error relating to the difference between the limb segments in lean tissue development.     

Intravenous tufted angioma

A case of a rare vascular tumor, intravenous tufted angioma, is described. A 51-year-old Japanese man presented with a 12x8 mm solitary reddish nodule on the right foot, which had been found at birth. Histologically, the tumor was confined to a malformed vein and was characterized by nodular aggregates of plump cells. The aggregates showed a compact proliferation of round cells, including capillary-forming cells. Venous angiomatous areas were also observed. No multinucleated giant cells were seen. Immunohistochemically, the capillary-forming cells in the aggregates and the endothelial cells in the angiomatous areas were positive for endothelial markers (factor VIII-related antigen, CD31, CD34). Pericyte-like cells expressing alpha-smooth muscle actin and muscle actin, and macrophage-like cells, which stained for factor XIIIa, were intermingled in the cellular aggregates. Flow cytometric analysis showed diploidy. The tumor may be a hamartomatous lesion modified by secondary reactive changes, and it may represent a distinctive clinicopathological entity that is closely related histogenetically and perhaps pathologically to tufted angioma and the recently described "giant cell angioblastoma".     

Morphological and functional differences in the elbow extensor muscle between highly trained male and female athletes

The purpose of this study was to investigate the difference in the morphological and functional aspects of the triceps brachii muscle between highly trained male and female athletes who were members of the 1996 Japanese Olympic teams in each of three different events: soccer, gymnastics and judo. The thickness (TB_mt) and fibre pennation angle (TB_pen) of the triceps brachii muscle and force output during elbow extensions were determined using a B-mode ultrasound apparatus and an isokinetic dynamometer, respectively. The TB_mt and its value relative to upper arm length (TB_mt/l _ua) were significantly larger in the men than in the women in all the events except judo. In all the subjects, a significant correlation was found between TB_mt/l _ua) and TB_pen (r= 0.721, P < 0.05). The existence of the sex difference in TB_pen within the same event was in agreement with that observed in TB_mt/l _ua except for the soccer players. The TB_pen of the soccer players were similar in both sexes although a significant sex differences was found in TB_mt/l _ua. The isokinetic forces measured using the two velocities 60°· s^?1 (F ₆₀) and 180°· s^?1 (F ₁₈₀) were significantly correlated to the cross-sectional area (CSA) of the triceps brachii muscle estimated from TB_mt (r= 0.702, P < 0.05 for F ₆₀, and r= 0.776, P < 0.05 for F ₁₈₀). No significant sex differences were found in either F ₆₀/CSA or F ₁₈₀/CSA in any of the events. From these results, it could be assumed, at least in the Olympic athletes tested in this study, that the fibre angulation of the triceps brachii muscle was almost the same in the two sexes if allowance was made for the difference in the muscle size, and the sex difference in force generation capability of the triceps brachii muscle could in the main be attributed to the difference in CSA rather than in the architectural characteristics.     

Mechanomyography of the human quadriceps muscle during incremental cycle ergometry

The mechanical activity of the human quadriceps muscle during maximal incremental cycle ergometry was investigated by mechanomyography (MMG). MMG and surface electromyography (EMG) recordings of vastus lateralis muscle activity were obtained from nine males. Cycle ergometry was performed at 60?rev/min and work load was incremented step wise by 20?W (3.2?Nm) every minute until volitional fatigue. The mean amplitudes of MMG (mMMG) and EMG (mEMG) during the contraction phase were calculated from the last six contractions in each load. The duration, load and work rate of exercise at exhaustion were 13.3 (1.6)?min, 44.1 (5.5)?Nm, 276.7 (34.7)?W, respectively. A linear relationship between mMMG and load was evident in each subject (r?=?0.868–0.995), while mEMG seemed to dissociate as the load became greater. In the grouped mean data, mMMG was linearly related to load whether aligned to the absolute (r?=?0.995) or maximal (r?=?0.995) load. Involvement of the noise component was further investigated by studying passive cycling by four subjects. Pedals were rotated passively for the first half of each stage (PAS) and the subject then pushed the pedals for the second half (ACT). In the lighter load region, the mMMG of ACT was as small as that of PAS. However, the change in the mMMG of PAS was very small compared with that of ACT. In conclusion, this study demonstrates a linear relationship between the mMMG of the quadriceps muscle and work load during maximal incremental cycle ergometry. The effect of movement noise was thought to be small and stable.     

Immunogenetic background of patients with autoimmune fatigue syndrome

We have previously reported that approximately 50% of children with chronic nonspecific complaints were positive for antinuclear antibodies (ANA), and that a novel autoantibody to a 62 kD protein (anti-Sa) was found in 40% of these ANA-positive patients. Therefore, we proposed a distinct disease entity termed autoimmune fatigue syndrome (AIFS). We hypothesized that if autoimmune mechanisms did play an important role in the pathogenesis of AIFS, it is possible that it is immunogenetically regulated as observed in other autoimmune disorders. In order to examine the immunogenetic background of AIFS patients, HLA-A, -B, -C, and -DR loci were analyzed serologically in 61 AIFS patients. AIFS was found to be positively associated with the class I antigen HLA-B61 and with the class II antigen HLA-DR9, with odds ratios of 2.77 (p = 0.015, Pcorr = 0.48) and 2.60 (p= 0.012, Pcorr = 0.17), respectively. A negative association was also found between AIFS and HLA-DR2 with odds ratio of 0.25 (p = 0.029, Pcorr = 0.041). When comparing anti-Sa positive AIFS patients with healthy controls, the odds ratios associated with HLA-B61, DR9, and DR2 were 3.42 (p = 0.021, Pcorr = 0.22), 3.96 (p = 0.0011, Pcorr = 0.015), and 0.16 (p = 0.0022, Porr = 0.031), respectively. Thus, the HLA associations observed in this study suggested that immunogenetic background might play a role in AIFS.