Effects of 5-aminolevulinic acid with iron supplementation on respiratory responses to graded cycling and interval walking training achievement in older women over 75 yrs.

BACKGROUND: Exercise training above a given intensity is necessary to prevent age-associated physical disability and diseases; however, the physical and psychological barriers posed by deteriorated physical fitness due to aging may hinder older people from performing daily exercise training. Because 5-aminolevulinic acid (ALA), a precursor of heme, reportedly improves mitochondrial function, we examined whether ALA, combined with sodium ferrous citrate (SFC) for enhancement, improved aerobic capacity and voluntary exercise training achievement in older women aged over 75 yrs. METHODS: The study was conducted using a placebo-controlled, double-blind crossover design. Fifteen women aged ~78 yrs. with no exercise habits underwent two trials for 7 days each where they performed interval walking training (IWT), repeating fast and slow speeds of walking for 3 min each, at >70% and at ~40% of peak aerobic capacity for walking, respectively, with ALA+SFC (100 and 115 mg/day, respectively) or placebo supplement intake (CNT), with a 12-day washout period. Before and after each trial, subjects underwent a graded cycling test while having their oxygen consumption rate (V·O2), carbon dioxide production rate (V·CO2), and plasma lactate concentration ([Lac-]p) measured. Furthermore, during the supplement intake period, exercise intensity for IWT was measured by accelerometry. RESULTS: In ALA+SFC, the increases in V·O2 and V·CO2 during the graded cycling test were attenuated (both, P < 0.01) with a 13% reduction in [Lac-]p (P = 0.012) while none of these attenuated responses occurred in CNT (all, P > 0.46). Furthermore, energy expenditure and time during fast walking for IWT were 25% (P = 0.032) and 21% (P = 0.022) higher in ALA+SFC than in CNT. CONCLUSION: Thus, ALA+SFC supplementation improved aerobic capacity and thus increased fast-walking training achievement in older women.

[Emergency incompatible red cell transfusion to a patient whose blood type was suspended from identification].

We report a case of a 59-year-old woman who presented with hypovolemic shock and compensated acidosis (preoperative arterial blood gases: pH 7.3, P(CO2) 31.9 mmHg, Pa(O2) 112.3 mmHg, base excess -9.8, Hb 6.4 g x dl(-1)) due to perforated descending colon, necessitating emergency surgery. Tracheal intubation had been performed preoperatively. Prior to induction of anesthesia, blood pressure was 106/74 mmHg, heart rate 119 beats x min(-1), and Sp(O2) 100% breathing room air. Anesthesia was induced with remifentanil influsion at a rate of 0.05 mg x kg(-1) x min(-1), sevoflurane 1% and rocuronium bromide 30mg, and was maintained with oxygen, air, remifentanil and sevoflurane. For a critical hypovolemia, in accordance to the guidelines for intraoperative critical hemorrhage and the Japanese practical guidelines for blood components therapy, we started to transfuse incompatible red cell (O+) since the identification of blood typing was suspended. The duration of surgery was 104 min, with an intraoperative total bleeding of 125 ml. Four units of total blood transfusion and 3,050 ml of infusion of Ringer's acetate solution were administered. The patient was transferred to ICU with tracheal intubation. No adverse reactions associated with blood type incompatibility were recognized.

[Viability period of the rabbit skeletal muscle in the Ca(2+)-induced Ca2+ release (CICR) test].

BACKGROUND: In Japan, malignant hyperthermia susceptibility (MHS) is diagnosed by detecting an enhanced rate of CICR from the sarcoplasmic reticulum in skinned skeletal muscle fibers. We usually consider the CICR test should be completed within 48 hours of muscle excision. We measured the viability period of the CICR test in the following four treatment groups. METHODS: Muscle bundles prepared from a rabbit were dissected and stored in muscle relaxant solution at -30 degrees C, 4 degrees C, 20 degrees C, and 37 degrees C. The CICR rate was measured in a part of the biopsied muscle using chemically skinned fibers that had been prepared according to Endo's method. RESULTS: With muscle bundles stored at -30 degrees C and 37 degrees C, the rate of CICR could not be measured. Function related CICR of the muscle stored at 4 degrees C and 20 degrees C lasted for four days. CONCLUSIONS: This results showed that rate of CICR can be measured for at least 4 days when skeletal muscle bundles of rabbits are stored both at 4 degrees C and at 20 degrees C. Further studies are expected including the optimum conditions on stored temperature and stored days in the human muscle.

Bisphenol A in combination with TNF-alpha selectively induces Th2 cell-promoting dendritic cells in vitro with an estrogen-like activity.

Bisphenol A (BPA) is a monomer used in manufacturing a wide range of chemical products, including epoxy resins and polycarbonate. BPA, an important endocrine disrupting chemical that exerts estrogen-like activities, is detectable at nanomolar levels in human serum worldwide. The pregnancy associated doses of 17beta-estradiol (E2) plus tumor-necrosis factor-alpha (TNF-alpha) induce distorted maturation of human dendritic cells (DCs) that result in an increased capacity to induce T helper (Th) 2 responses. The current study demonstrated that the presence of BPA during DC maturation influences the function of human DCs, thereby polarizing the subsequent Th response. In the presence of TNF-alpha, BPA treatment enhanced the expression of CC chemokine ligand 1 (CCL1) in DCs. In addition, DCs exposed to BPA/TNF-alpha produced higher levels of IL-10 relative to those of IL-12p70 on CD40 ligation, and preferentially induced Th2 deviation. BPA exerts the same effect with E2 at the same dose (0.01-0.1 microM) with regard to DC-mediated Th2 polarization. These findings imply that DCs exposed to BPA will provide one of the initial signals driving the development and perpetuation of Th2-dominated immune response in allergic reactions.

Cytokine-dependent modification of IL-12p70 and IL-23 balance in dendritic cells by ligand activation of Valpha24 invariant NKT cells.

CD1d-restricted invariant NKT (iNKT) cells play crucial roles in various types of immune responses, including autoimmune diseases, infectious diseases and tumor surveillance. The mechanisms underlying their adjuvant functions are well understood. Nevertheless, although IL-4 and IL-10 production characterize iNKT cells able to prevent or ameliorate some autoimmune diseases and inflammatory conditions, the precise mechanisms by which iNKT cells exert immune regulatory function remain elusive. This study demonstrates that the activation of human iNKT cells by their specific ligand alpha-galactosylceramide enhances IL-12p70 while inhibiting the IL-23 production by monocyte-derived dendritic cells, and in turn down-regulating the IL-17 production by memory CD4(+) Th cells. The ability of the iNKT cells to regulate the differential production of IL-12p70/IL-23 is mainly mediated by a remarkable hallmark of their function to produce both Th1 and Th2 cytokines. In particular, the down-regulation of IL-23 is markedly associated with a production of IL-4 and IL-10 from iNKT cells. Moreover, Th2 cytokines, such as IL-4 and IL-13 play a crucial role in defining the biased production of IL-12p70/IL-23 by enhancement of IL-12p70 in synergy with IFN-gamma, whereas inhibition of the IFN-gamma-promoted IL-23 production. Collectively, the results suggest that iNKT cells modify the IL-12p70/IL-23 balance to enhance the IL-12p70-induced cell-mediated immunity and suppress the IL-23-dependent inflammatory pathologies. These results may account for the long-appreciated contrasting beneficial and adverse consequence of ligand activation of iNKT cells.

Identification of functional type 1 ryanodine receptors in human dendritic cells.

Ryanodine receptor (RyR) is a Ca(2+) channel that mediates Ca(2+) release from intracellular stores. Altered Ca(2+) homeostasis in skeletal muscle which usually occurs as a result of point mutations in type 1 RyR1 (RyR1) is a key molecular event triggering malignant hyperthermia (MH). There are three RyR isoforms, and we herein show, for the first time, that human dendritic cells (DCs) preferentially express RyR1 mRNA among them. The RyR activator, 4-chloro-m-cresol (4CmC), induced Ca(2+) release in DCs, and this response was eliminated by dantrolene, an inhibitor of the RyR1, and was unaffected by xestospongin C, a selective inhibitor of IP(3) receptor. Activation of RyR1 reduced LPS-induced IL-10 production, promoted the expression of HLA-DR and CD86, and thereby exhibited an improved capacity to stimulate allogeneic T cells. These findings demonstrate that RyR1-mediated calcium signaling modifies diverse DC responses and suggest the feasibility of using DC preparations for the diagnosis of MH.

[Pulmonary embolism induced by evacuator during transurethral resection of the prostate].

A 79-year-old man was scheduled to undergo transurethral resection of the hypertrophied prostate during general anesthesia. Anesthesia was maintained with sevoflurane 0.5-1.0% and nitrous oxide 50% in oxygen mixture. Immediately after using an evacuator to remove small resected pieces of the prostate, end-tidal carbon dioxide pressure (EtCO2) decreased suddenly from 31 mmHg to 18 mmHg. Concurrently, decreases in systolic blood pressure from 110 mmHg to 60 mmHg and oxygen saturation from 100% to 95%, and an increase in arterial-alveolar carbon dioxide tension difference (a-ADCO2) were observed. We initially suspected the onset of pulmonary thrombosis as the cause of these events, ventilated the patient's lungs with 100% oxygen and administered 5,000 units of heparine and vasopressors intravenously. However, transesophageal echocardiography done subsequently revealed the presence of strongly echogenic images compatible with the air in the left cardiac atrium and the contribution of the air to those events. The EtCO2, blood pressure, and oxygen saturation improved in about 20 minutes after the initial decrease of the EtCO2 had been detected. Thereafter, surgical procedure was done uneventfully. In routine anesthetic management of transurethral surgery, it should be considered that the sudden deterioration in vital signs may have been caused by evacuator used.

Malignant hyperthermia in Japan: mutation screening of the entire ryanodine receptor type 1 gene coding region by direct sequencing.

BACKGROUND: Malignant hyperthermia (MH) is a disorder of calcium homeostasis in skeletal muscle triggered by volatile anesthetics or succinylcholine in susceptible persons. More than 100 mutations in the ryanodine receptor type 1 gene (RYR1) have been associated with MH susceptibility, central core disease, or both. RYR1 mutations may account for up to 70% of MH-susceptible cases. The authors aimed to determine the frequency and distribution of RYR1 mutations in the Japanese MH-susceptible population. METHODS: The authors selected 58 unrelated Japanese diagnosed as MH-susceptible for having an enhanced Ca-induced Ca release rate from the sarcoplasmic reticulum on chemically skinned muscle fibers. They sequenced the entire RYR1 coding region from genomic DNA. Muscle pathology was also characterized. RESULTS: Seven previously reported and 26 unknown RYR1 potentially pathogenic sequence variations were identified in 33 patients (56.9%). Of these patients, 48% had cores on muscle biopsy. The mutation detection rate was higher in patients with clear enhancement of Ca-induced Ca release rate (72.4%), whereas all patients with central core disease had RYR1 mutations. Six patients harbored potentially causative compound heterozygous sequence variations. CONCLUSIONS: Distribution and frequency of RYR1 mutations differed markedly from those of the North American and European MH-susceptible population. Comprehensive screening of the RYR1 gene is recommended for molecular investigations in MH-susceptible individuals, because many mutations are located outside the "hot spots." Based on the observed occurrence of compound heterozygous state, the prevalence of a possibly predisposing phenotype in the Japanese population might be as high as 1 in 2,000 people.

Central core disease is due to RYR1 mutations in more than 90% of patients.

Ryanodine receptor 1 (RYR1) gene mutations are associated with central core disease (CCD), multiminicore disease (MmD) and malignant hyperthermia (MH), and have been reported to be responsible for 47-67% of patients with CCD and rare cases with MmD. However, to date, the true frequency and distribution of the mutations along the RYR1 gene have not been determined yet, since mutation screening has been limited to three 'hot spots', with particular attention to the C-terminal region. In this study, 27 unrelated Japanese CCD patients were included. Clinical histories and muscle biopsies were carefully reviewed. We sequenced all the 106 exons encoding RYR1 with their flanking exon-intron boundaries, and identified 20 novel and 3 previously reported heterozygous missense mutations in 25 of the 27 CCD patients (93%), which is a much higher mutation detection rate than that perceived previously. Among them, six were located outside the known 'hot spots'. Sixteen of 27 (59%) CCD patients had mutations in the C-terminal 'hot spot'. Three CCD patients had a probable autosomal recessive disease with two heterozygous mutations. Patients with C-terminal mutations had earlier onset and rather consistent muscle pathology characterized by the presence of distinct cores in almost all type 1 fibres, interstitial fibrosis and type 2 fibre deficiency. In contrast, patients with mutations outside the C-terminal region had milder clinical phenotype and harbour more atypical cores in their muscle fibres. We also sequenced two genes encoding RYR1-associated proteins as candidate causative genes for CCD: the 12 kD FK506-binding protein (FKBP12) and the alpha1 subunit of L-type voltage-dependent calcium channel or dihydropyridine receptor (CACNA1S). However, no mutation was found, suggesting that these genes may not, or only rarely, be responsible for CCD. Our results indicate that CCD may be caused by RYR1 mutations in the majority of patients.

Effect of bupivacaine enantiomers on Ca2+ release from sarcoplasmic reticulum in skeletal muscle.

Local anesthetics affect intracellular Ca2+ movement in the myocyte. The use of isomers may help to reveal specific mechanisms of action, such as receptor mediation. In the present study, we used skinned fibers from mammalian skeletal muscle to test whether bupivacaine enantiomers had different effects on Ca2+ release and uptake by the sarcoplasmic reticulum, and on the Ca2+ sensitivity of the contractile system. Ca2+-induced Ca2+ release was enhanced by S-bupivacaine 1 approximately 3 mM, but inhibited by R-bupivacaine 3 mM, remaining unaffected at lower doses. These enantiomers inhibited Ca2+ uptake to different degrees, with R-bupivacaine having a stronger effect. Ca2+ sensitivity of the contractile system was equally enhanced by R- and S-bupivacaine. These findings might help to explain the myoplasmic Ca2+ elevation induced by bupivacaine. The observed stereoselectivity suggests effects on specific proteins, the ryanodine Ry1 receptor and the Ca2+-ATPase pump, rather than non-specific increase in Ca2+ permeability.