Regulation of autophagy in chick myotube cultures: Effect of uncoupling mitochondrial oxidative phosphorylation

Abstracts: Skeletal muscles have a high demand for ATP, which is met largely through mitochondria oxidative phosphorylation. Autophagy is essential for the maintenance of skeletal muscle mass under catabolic conditions. This study investigated the effect of uncoupling mitochondrial oxidative phosphorylation on autophagy in chicken skeletal muscle. Chick myotubes were incubated with the mitochondrial uncoupler carbonyl cyanide m-chlorophenyl hydrazone (CCCP) at 25 μM for 3h. CCCP prevented the phosphorylation of p70 ribosomal S6 kinase 1 (Thr389), S6 ribosomal protein (Ser240/244), and eukaryotic translation initiation factor 4E-binding protein 1 (Thr37/46), which are the measures of the mechanistic target of rapamycin complex 1 (mTORC1) activity. CCCP significantly increased cytoplasmic and mitochondrial LC3-II content, which act as indices of index for autophagosome formation and mitophagy, respectively, but did not influence the expression of autophagy-related genes LC3B, GABARAPL1, and ATG12. Finally, surface sensing of translation method revealed that protein synthesis, a highly energy consuming process, was significantly decreased upon CCCP treatment. These results indicate that the uncoupling of mitochondrial oxidative phosphorylation stimulates autophagy and inhibits protein synthesis through mTORC1 signaling in chick myotube cultures.

Effects of low-protein diet and feed restriction on mRNA expression of cationic amino acid transporters in porcine skeletal muscles

We investigated the effects of a low-protein diet and feed restriction on the mRNA expression of cationic amino acid transporters (CATs) in the longissimus dorsi (LD), rhomboideus (RH), and biceps femoris (BF) muscles of pigs. Eighteen piglets were divided into three groups: a control (CP21%), low-protein diet (LP, CP16%), and feed-restricted diet (FR, CP21%, 76% feed intake of control pigs) groups. The expression levels of CAT-1 in the LD and BF muscles of LP pigs were higher than that of control pigs, whereas that of FR pigs showed no difference. The CAT-2A expression levels in the RH muscle of FR pigs were higher than that of control pigs. The free lysine concentrations in all muscles of LP and FR pigs were lower than that of control pigs. To examine the factors that affect CATs mRNA expression, we evaluated the effects of lysine, arginine, insulin-like growth factor-I, and dexamethasone on the expression of CATs in C2C12 myotubes. CAT-1 expression levels increased in lysine and/or arginine deprivation. We show that CAT-1 and CAT-2A expression levels in skeletal muscles differ in response to dietary treatments and CAT-1 expression in skeletal muscles appears to increase in response to low free lysine concentrations.

P183 Arterial stiffness was inversely associated with left ventricular diastolic function in indigenous Papuan populations

Background

Age-related increase in systolic pressure is known to be absent in indigenous Papuan populations, partially because of their life-long low-sodium and high-potassium diets.

Purpose

The aim of this study was to investigate the age-related change in left ventricular (LV) systolic and diastolic function and the relationship with arterial hemodynamics among the indigenous Papuan highland people. 

Methods

Indices of arterial hemodynamics were measured using oscillometric brachial cuff-based sphygmomanometer (Mobil-O-Graph). Brachial-ankle pulse wave velocity (baPWV) was measured using a semiautomatic device (form ABI/baPWV). LV systolic and diastolic function was evaluated by 2-dimensional echocardiography and tissue-Doppler imaging using Vivid iq.

Results

A total of 81 native Papuans (median age 42 years, 47% women) were enrolled in this study. None of the subjects took any medicines, particularly antihypertensive drugs. All participants presented in sinus rhythm. With ageing, LV mass index remained unchanged, and LV ejection fraction increased, but mildly reduced (40–50%) in 3 participants. Transmitral E-wave velocity slightly decrease but the change was not significant. Transmitral A-wave velocity markedly increased (ρ=0.60, P < 0.001) and E/A ratio decreased with age (ρ=-0.52, P < 0.001). Age-related change of E-wave deceleration time was not significant. Septal e′ (ρ=-0.60, P < 0.001) and lateral e′ decreased (ρ=-0.53, P < 0.001) and average E/e′ increased with age (ρ=0.44, P < 0.001). Left atrial volume index did not change significantly with age. In multivariate regression analysis, baPWV was independently associated with E/e" ratio both before and after adjustment for age, sex, body mass index, mean arterial pressure, and heart rate; however, indices of wave reflection including augmentation index and reflection magnitude were not associated with E/e′. Only age and heart rate were inversely associated with E/A ratio. 

Conclusion

LV systolic function was preserved in indigenous Papuan populations; however, LV diastolic function decreased with ageing. Age-related arterial stiffening, not wave reflection, was inversely related to LV diastolic function.

Effects of dietary lysine levels and lighting conditions on intramuscular fat accumulation in growing pigs

This study was conducted to test our hypothesis that intramuscular fat (IMF) accumulation increases in pigs fed on a low lysine diet during the dark period than those fed on the same diet during the light period. Using barrows aged 6 weeks, we monitored whether serum glucose and insulin levels were affected by light conditions. Two diets with different levels of lysine, 0.78% (LL diet) and 1.37% (control diet) were prepared. Eight pigs were fed on the diet during the light period, while the remaining pigs were fed during the dark period. The pigs were fed either the LL diet or the control diet. Although IMF contents of Longissimus dorsi (LD) muscle were higher in the pigs fed on a LL diet (p < .05), the light conditions had no effect. Low dietary lysine caused reduction in serum glucose levels (p < .05) and serum insulin levels (p = .0613). However, they were also unaffected by the lighting conditions. To gain further insights, we determined the messenger RNA levels of insulin receptor, insulin receptor substrate 1, acetyl CoA carboxylase, and fatty acid synthase in LD and Rhomboideus muscles and in the liver.

Regulation of Autophagy in Chick Myotubes: Effects of Insulin, Insulin-Like Growth Factor-I, and Amino Acids

Autophagy, an intracellular bulk protein degradation system in skeletal muscle, is increased under catabolic conditions resulting in muscle atrophy. This study aimed to investigate the effects of insulin, insulin-like growth factor (IGF)-I, and amino acids on autophagy (LC3-II content and expression of autophagy-related genes) in chick myotubes. Chick myotubes were incubated with insulin (1 µg/ml), IGF-I (100 ng/ml), and amino acids for 3 h. The LC3-II content, an index of autophagosome formation, and mRNA expression of LC3B and GABARAPL1 were significantly decreased by insulin. The LC3-II content, but not mRNA expression of autophagy-related genes, was also significantly decreased by IGF-I. The LC3-II content and LC3B mRNA level were also significantly decreased by amino acids. The mRNA expression of atrogin-1/MAFbx, a muscle-specific ubiquitin ligase, was also significantly decreased by insulin, IGF-I, and amino acids in chick myotubes. These results indicated that insulin, IGF-I, and amino acids regulate autophagy as well as the ubiquitin-proteasome proteolytic pathway in chick myotubes.

Erratum: Observation of the hyperfine spectrum of antihydrogen

This corrects the article DOI: 10.1038/nature23446.

Observation of the hyperfine spectrum of antihydrogen

The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 10¹³ are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 10⁴. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.

Antihydrogen accumulation for fundamental symmetry tests

Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles.

Antihydrogen studies are important in testing the fundamental principles of physics but producing antihydrogen in large amounts is challenging. Here the authors demonstrate an efficient and high-precision method for trapping and stacking antihydrogen by using controlled plasma.

Expression of cationic amino acid transporters in pig skeletal muscles during postnatal development

The cationic amino acid transporter (CAT) protein family transports lysine and arginine in cellular amino acid pools. We hypothesized that CAT expression changes in pig skeletal muscles during rapid pig postnatal development. We aimed to investigate the tissue distribution and changes in the ontogenic expression of CATs in pig skeletal muscles during postnatal development. Six piglets at 1, 12, 26, 45, and 75 days old were selected from six litters, and their longissimus dorsi (LD), biceps femoris (BF), and rhomboideus (RH) muscles, and their stomach, duodenum, jejunum, ileum, colon, liver, kidney, heart, and cerebrum were collected. CAT-1 was expressed in all the 12 tissues investigated. CAT-2 (CAT-2A isoform) expression was highest in the skeletal muscle and liver and lowest in the jejunum, ileum, kidney, and heart. CAT-3 was expressed mainly in the colon and detected in the jejunum, ileum, and cerebrum. The CAT-1 expression was higher in the skeletal muscle of day 1 pigs than in that of older pigs (P < 0.05). The CAT-2 mRNA level was lowest at day 1, but increased with postnatal development (P < 0.05). There was no significant change in CAT-1 expression among the LD, BF, and RH during postnatal development (P > 0.05); however, there was a change in CAT-2 expression. The CAT-2 expression was highest in the LD of 12-, 26-, 45-, and 75-day-old pigs, followed by the BF and RH (P < 0.05). These results suggest that CAT-1 and CAT-2 play different roles in pig skeletal muscles during postnatal development.

Changes in muscle fiber type and expression of mRNA of myosin heavy chain isoforms in porcine muscle during pre- and postnatal development

The purpose of this study is to elucidate developmental changes in muscle fiber type in the pig during pre- and postnatal development. For this purpose, we performed a histochemical analysis for myosin adenosine triphosphatase activity to assess muscle fiber type and determined abundances of messenger RNA (mRNA) of myosin heavy chain (MHC) isoforms. Samples of Longissimus dorsi (LD) muscle were taken from fetuses on day 90 of the fetal stage. Further, samples of LD, Rhomboideus and Biceps femoris (B. femoris) muscles were taken from pigs when they were 1, 12, 26, 45 or 75 days old. Expression of MHC 2b mRNA in the LD and the B. femoris muscles rapidly and considerably increased from the late fetal stage to the early postnatal stage and this increase was associated with the development of type 2b fibers at least in the LD muscle. As shown by the rapid and considerable changes in expression of MHC 2b mRNA, it seems that a certain plasticity of muscle fiber type still remains in this developmental stage.

Effects of Orally Administrated Amino Acids on Myofibrillar Proteolysis in Chicks

We examined the effects of orally administrated amino acids on myfibrillar proteolysis in food-deprived chicks. Plasma N(tau)-methylhistidine concentration, as an index of myofibrillar proteolysis, was decreased by the administration of Glu, Gly, Ala, Leu, Ile, Ser, Thr, Met, Trp, Asn, Gln, Pro, Lys and Arg but not by Asp, Val, Phe, Tyr or His to chicks. Orally administrated Cys was fatal to chicks. These results indicate that oral Glu, Gly, Ala, Leu, Ile, Ser, Thr, Met, Trp, Asn, Gln, Pro, Lys and Arg administration suppressed myofibrillar proteolysis in chicks.

Effects of low protein diet and low protein diet supplemented with synthetic essential amino acids on meat quality of broiler chickens

We investigated the effects of a low crude protein (CP) diet and a low CP diet supplemented with synthetic essential amino acids (EAA) on the meat quality of broiler chickens. Twenty-one-day-old chickens were assigned to one of three diets: control, low CP (LCP), or low CP supplemented with EAA (ELCP). The chickens received these diets for 10 days. The shear force value (SFV) and free glutamate content of the Pectoralis major muscle were measured as indicators of the meat toughness and taste. The collagen and crude fat content of the muscle and the cross-sectional area of myofibers were measured to evaluate the effects of the LCP and ELCP diets on meat toughness. The SFV of the ELCP group was 47% lower than that of the control group (P<0.01). However, the LCP diet did not affect the SFV. The collagen and crude fat content were not affected by the dietary treatment. The cross-sectional area was lower in the LCP and ELCP groups (P<0.05) than the control group. The free glutamate content of muscle was not affected by the dietary treatment. Thus, a low CP diet supplemented with EAA is an effective means of producing tender meat.

Muscle protein metabolism during compensatory growth with changing dietary lysine levels from deficient to sufficient in growing rats

Livestock and laboratory animals show compensatory growth when they are fed ad libitum following a period of restriction feeding. Lysine is a major limiting essential amino acid in the diets both for humans and animals. We hypothesized that changing dietary lysine levels from deficient to sufficient induced compensatory growth in young rats. We elucidated the effect of lysine sufficiency on the dynamics of hormones, relevant to muscle protein synthesis and degradation, insulin-like growth factor-I (IGF-I) and corticosterone, and on the expression of proteolytic-related genes in skeletal muscle during compensatory growth. Lysine sufficiency where the dietary lysine level was increased from 0.46% to 1.30% after 2 wk of subjecting the rats to the lower lysine level induced 80% enhancement of growth rate of rats. During compensatory growth with the lysine sufficiency, fractional muscle protein synthesis rates were higher whereas fractional muscle protein degradation rates were lower than those of the control group (p<0.05). After lysine sufficiency, the expression of atrogin-1/MAFbx mRNA was decreased in gastrocnemius muscle (p<0.05). With the lysine sufficiency, serum IGF-I concentration increased (p<0.05) whereas serum corticosterone decreased (p<0.05). These findings suggest that compensatory growth with lysine sufficiency is due to a change of hormone levels before and after changing diets, resulting in incrementation of protein synthesis and suppression of protein degradation of skeletal muscle.

Nitrogen balance during compensatory growth when changing the levels of dietary lysine from deficiency to sufficiency in growing pigs

Two experiments were conducted to elucidate the nitrogen (N) balance of pigs exhibiting compensatory growth when changing the dietary lysine levels from deficiency to sufficiency. Experiment 1 elucidated whether pigs exhibited compensatory growth with dietary lysine sufficiency. Twenty 6-week-old males were assigned to one of two treatments: control and LC (lysine and control). Control pigs were fed a control diet throughout the 24-day experimental period, whereas LC pigs were fed a low lysine diet until day 21 of the experiment, followed by the control diet until the end of experiment. The dietary lysine sufficiency treatment induced an 80% increase in the growth rate of LC pigs (P < 0.05). Experiment 2 focused on the N balance of pigs that exhibited compensatory growth with dietary lysine sufficiency. Eighteen 6-week-old males were assigned to one of three treatments: control, LC, and LL (low lysine). LL pigs were fed a low lysine diet throughout the 24-day experimental period. Pigs that exhibited compensatory growth with dietary lysine sufficiency tended to retain a higher amount of N than control pigs (P = 0.10). These finding suggest that the compensatory growth induced in pigs by dietary lysine sufficiency was partly attributable to a higher level of N retention.

Shape Memory Behavior of Ti-Ni Thin Films Annealed at Various Temperatures

Ti-Ni thin films with three different types of compositions, titanium-rich Ti-Ni, near equiatomic TiNi and nickel-rich Ti-Ni were prepared by sputtering. The sputter-deposited films were annealed at various temperatures between 773 and 973K in order to crystallize. After the heat treatment, the shape memory behavior was examined with a thermomechanical tester. The shape memory behavior of the near equiatomic composition films was not affected by the heat treatment. On the other hand, the shape memory behavior of the other composition films strongly depended on the annealing temperature. As the annealing temperature increases, the martensitic and reverse martensitic transformation temperatures of the nickel-rich films decreased and those of the titanium-rich films increased. These opposite behaviors of the transformation temperatures can be explained by the opposite dependence of the precipitation of the second phase on the annealing temperature. All the nickel-rich films exhibited good shape memory effect over a wide range of stress, while all the titanium-rich films exhibited a small plastic strain only in the stress range where the shape changes associated with both the R-phase and the martensitic transformations were observed.

A Study of Trap Profiles in Thin Silicon Dioxide Films at Dielectric Breakdown Using Percolation Model

A Monte Carlo simulation of wear-out process in thin silicon dioxide films is performed to investigate the correlation between the electron trap distribution and the dielectric breakdown. Non-uniformity of the trap generation and its dependence on the stress conditions are monitored by the measurements of the charge centroid. In order to include these experimental observations into Degraeve's percolation model [IEDM Tech. Dig., pp.863-866 (1995)], we introduce exponential trap profiles decaying from the Si/SiO2 interface. Our new model successfully reproduces critical threshold voltage shifts from the information about critical charge centroids for various stress conditions. Finally, as a reasonable explanation of the stress dependent breakdown properties, we suggest that the bond strain caused by lattice mismatch at the interface is accelerated by the electric field.

Impact of superselective transarterial infusion therapy of high-dose cisplatin on maxillary cancer with orbital invasion

BACKGROUND AND PURPOSE

We have been performing the superselective transarterial infusion of high-dose cisplatin for advanced maxillary cancer since 1998 and the local control rate, disease free survival rate, and organ preservation have improved markedly compared with our former therapy. This study evaluates the effectiveness of superselective transarterial infusion therapy by using high-dose cisplatin on maxillary cancer with orbital invasion.

MATERIALS AND METHODS

We treated 23 patients with maxillary cancer by using superselective transarterial infusion therapy with high-dose cisplatin and concomitant radiation therapy for 10 years. Of all patients, 15 showed orbital invasion, with 11 of these tumors fed by both internal maxillary and ophthalmic arteries. In all patients, we performed superselective transarterial infusion therapy via the internal maxillary artery and/or the other feeding branches from the external carotid artery. After the operation, we determined whether a pCR had occurred by checking for the presence of viable cells. In addition, we calculated the overall survival rate, preservation rate of the eyeball, and disease-free survival rate.

RESULTS

For all 23 patients, pCR and overall survival rates were 95.7% and 78.4%, respectively. To date, 2 of these patients died of lung metastasis without local recurrence. For the 15 patients with orbital invasion, the respective pCR and disease-free survival rates were 93.3% and 87.5%. Eyeballs were preserved in all patients, and local recurrence occurred in only 1 patient, at the inferior wall of the maxillary sinus (not in the orbit).

CONCLUSIONS

Superselective transarterial infusion therapy with high-dose cisplatin remarkably improved the local control rate and disease-free survival rate of maxillary cancer. Even in patients with orbital invasion, a high local control rate was achieved, with preservation of the eyeball, through infusion only into branches of the external carotid artery.

Three-year cardiovascular events and disease progress in patients with peripheral arterial disease: results from the Japan Medication Therapy for Peripheral Arterial Disease (J-METHOD)

AIM

To investigate the current status of peripheral arterial disease (PAD) drug treatment in Japan, and the effects of drug treatment, risk factors, and complications on disease progress and onset of cardiovascular events in PAD patients.

METHODS

In this prospective observational cohort study, 557 PAD patients were followed up for 3 years, and the current status of PAD treatment, risk factors, and cardiovascular events were monitored.

RESULTS

Three drugs, i.e., beraprost sodium, cilostazol, and aspirin, were most frequently used. The patients who had undergone vascular reconstruction of the lower limbs before enrollment showed significant improvement in ABI. Among the patients who had not undergone vascular reconstruction before enrollment, there was a significant improvement in ABI after treatment with beraprost. During the observation period, cardiovascular deaths occurred in 35 patients (6.3%), heart diseases in 63 (11.3%), brain diseases in 39 (7.0%), and events in the lower limbs in 94 (16.9%). The factors affecting the increase of the cardiovascular events were explored by multivariate analysis (Cox regression analysis). As a result, age (75 years or older), ischemic heart disease and increase in severity on the Fontaine classification were identified as significant factors for cardiovascular deaths, whereas kidney disorders and increase in severity on the Fontaine classification were identified for heart diseases, the number of oral drugs for treating PAD was identified for brain diseases, and age (younger than 75 years), dialysis, ABI (less than 0.7) and aspirin were identified for the events in the lower limbs.

CONCLUSION

As a result of the three-year follow-up on the Japanese PAD cohort, the current status of PAD treatment, risk factors, and cardiovascular events could be identified.

Presence of quorum-sensing inhibitor-like compounds from bacteria isolated from the brown alga Colpomenia sinuosa

AIMS

Several Gram-negative bacterial species use N-acyl homoserine lactone (AHL) molecules as quorum-sensing (QS) signals to regulate various biological functions. Similarly, various bacteria can stimulate, inhibit or inactivate QS signals in other bacteria by producing molecules called as quorum-sensing inhibitors (QSI). Our aim was to screen and identify the epibiotic bacteria associated with brown algae for their ability of producing QS-inhibiting activity.

METHODS AND RESULTS

QSI screenings were conducted on several epibiotic bacteria isolated from a marine brown alga Colpomenia sinuosa, using Serratia rubidaea JCM 14263 as an indicator organism. Strain JCM 14263 controls the production of red pigment, prodigiosin by AHL QS. Out of 96 bacteria, which were isolated from the surface of the brown alga, 12% of strains showed the ability to produce QSI, which was observed from the pigmentation inhibition on Ser. rubidaea JCM 14263 without affecting its growth. Phylogenetic analysis using 16S rRNA gene sequencing method demonstrated bacterial isolates showing QS inhibition-producing bacteria belonging to the Bacillaceae (Firmicutes), Pseudomonadaceae (Proteobacteria), Pseudoalteromonadaceae (Proteobacteria) and Vibrionaceae (Proteobacteria).

CONCLUSION

An appreciable percentage of bacteria isolated from the brown alga produced QSI-like compounds.

SIGNIFICANCE AND IMPACT OF THE STUDY

The screening method using Ser. rubidaea described in this report will facilitate the rapid identification of QSI-producing bacteria from marine environment. This study reveals new avenue for future environmental applications. This study also suggests that these algal epibiotic bacteria may play a role in the defensive mechanism for their host by producing QSI or QSI-like compounds to suppress the settlement of other competitive bacteria.

[Aortic dissection after aortic valve replacement with an aorto-left atrial fistula; report of a case]

Aortocameral fistula is a rare complication of aortic dissection. We herein report a case of aortic dissection after aortic valve replacement (AVR) complicated with a fistula to the left atrium. A 76-year-old man who had undergone AVR 1 year previously, was admitted to our hospital because of facial edema and chest discomfort. On auscultation, a continuous murmur was heard at the left lower sternal border. Computed tomography revealed dissecting aneurysm of the ascending aorta and a fistula to the left atrium was suspected. Transesophageal echocardiography showed the fistula between the false lumen of the aneurysm and the left atrium. Ascending aorta replacement and closure of the fistula was performed. There was dense adhesion between the aortic root and the roof of the left atrium. It seems that postoperative adhesion plays an important role in formation of aortocameral fistula.

[Full-thickness pleural biopsy using an Insulation-tipped Diathermic Knife in a patient with malignant pleural mesothelioma]

A 72-year-old woman was pointed out a right pleural effusion and thickening pleura on the chest computed tomography. The patient underwent semiflexible thoracoscopy under local anesthesia at the endoscopy room. The patient was placed in the lateral decubitus position, and flexible trocar was inserted with the single puncture technique. At the macroscopic findings, the parietal pleura were thickened prominently, and patchy plaques were occasionally recognized. A standard biopsy forceps hardly grasped pleura because of presence of scar, so we performed pleural biopsy using Insulation-tipped Diathermic (IT) knife. A subpleural injection of saline containing 0.5% lidokine and 0.005% epinephrine was performed for raising the affected parietal pleura with an injection needle. After a pin hole was made, the pleural lesion was incised in a circle by manipulating the IT knife, and the incised pleura were removed. Pathology revealed extensive fibrosis and epithelial mesothelioma by the specimen. This biopsy technique using IT knife through semiflexible thoracoscopy enabled to obtain a full-thickness pleura It is thought to be useful for the diagnosis of malignant pleural mesothelioma (MPM) in which standard forceps are difficult to grasp.

Negative regulation of multifunctional Ca2+/calmodulin-dependent protein kinases: physiological and pharmacological significance of protein phosphatases

Multifunctional Ca2+/calmodulin-dependent protein kinases (CaMKs) play pivotal roles in intracellular Ca2+ signaling pathways. There is growing evidence that CaMKs are involved in the pathogenic mechanisms underlying various human diseases. In this review, we begin by briefly summarizing our knowledge of the involvement of CaMKs in the pathogenesis of various diseases suggested to be caused by the dysfunction/dysregulation or aberrant expression of CaMKs. It is widely known that the activities of CaMKs are strictly regulated by protein phosphorylation/dephosphorylation of specific phosphorylation sites. Since phosphorylation status is balanced by protein kinases and protein phosphatases, the mechanism of dephosphorylation/deactivation of CaMKs, corresponding to their 'switching off', is extremely important, as is the mechanism of phosphorylation/activation corresponding to their 'switching on'. Therefore, we focus on the regulation of multifunctional CaMKs by protein phosphatases. We summarize the current understanding of negative regulation of CaMKs by protein phosphatases. We also discuss the biochemical properties and physiological significance of a protein phosphatase that we designated as Ca2+/calmodulin-dependent protein kinase phosphatase (CaMKP), and those of its homologue CaMKP-N. Pharmacological applications of CaMKP inhibitors are also discussed. These compounds may be useful not only for exploring the physiological functions of CaMKP/CaMKP-N, but also as novel chemotherapies for various diseases.

Generation of anti-tumour effector T cells from naïve T cells by stimulation with dendritic/tumour fusion cells

Tumour-draining lymph node T cells are an excellent source of effector T cells that can be used in adoptive tumour immunotherapy because they have already been sensitized to tumour-associated antigens in vivo. However, such tumour-specific immune cells are not readily obtained from the host due to poor immunogenicity of tumours and reduced host immune responses. One obstacle in implementation of adoptive immunotherapy has been insufficient sensitization and expansion of tumour-specific effector cells. In this study, we aim to improve adoptive immunotherapy by generating anti-tumour effector T cells from naïve T lymphocytes. We attempted to achieve this by harnessing the advantages of dendritic cell (DC)-based anti-cancer vaccine strategies. Electrofusion was routinely employed to produce fusion cells with 30-40% efficiency by using the poorly immunogenic murine B16/F10 cell line, D5 cells, and DC generated from bone marrow cells. CD62L-positive T cells from spleens of naïve mice and the fusion cells were cocultured with a low concentration of IL-2. After 9 days of culture, the antigen-specific T cells were identified with an upregulation of CD25 and CD69 expression and a downregulation of CD62L expression. These cells secreted IFN-gamma upon stimulation with irradiated tumour cells. Moreover, when transferred into mice with 3-day established pulmonary metastases, these cells with coadministration of IL-2 exhibited anti-tumour efficacy. In contrast, naïve T cells cocultured with a mixture of unfused DC and irradiated tumour cells did not exhibit anti-tumour efficacy. Our strategy provides the basis for a new approach in adoptive T cell immunotherapy for cancer.

Effects of orally administered glycine on myofibrillar proteolysis and expression of proteolytic-related genes of skeletal muscle in chicks

We examined the effects of orally administered glycine on myofibrillar proteolysis in food-deprived chicks. Food-deprived (24 h) chicks were orally administered 57, 113, and 225 mg glycine/100 g body weight and killed after 2 h. The plasma N(tau)-methylhistidine concentration, used as myofibrillar proteolysis, was decreased by glycine. We also examined the expression of proteolytic-related genes by real-time PCR of cDNA from chick skeletal muscles. The mRNA expression of atrogin-1/MAFbx, proteasome C2 subunit, m-calpain large subunit, and cathepsin B was decreased by glycine in a dose-dependent manner. The plasma corticosterone concentration was also decreased by glycine, but the plasma insulin concentration was unaffected. These results indicate that orally administered glycine suppresses myofibrillar proteolysis and expression of proteolytic-related genes of skeletal muscle by decreasing the plasma corticosterone concentration in chicks.

Successful management of critical limb ischemia with intravenous sodium thiosulfate in a chronic hemodialysis patient

Vascular calcification is common among hemodialysis (HD) patients and contributes to the development of peripheral arterial disease. A 57-year-old Japanese man who had been on HD for 30 years was referred to us for severe pain with multiple ulcers on his toes and fingers. He was an ex-smoker and had no diabetes mellitus. On admission, he had ulcers on his big toes bilaterally and right 2nd - 4th fingers. Peripheral pulses were strong and his ankle-brachial pressure index was above 1.3. Laboratory data were as follows: calcium 9.9 mg/dl, albumin 3.3 g/dl, phosphate 3.0 mg/dl, Ca x P product 30, and parathyroid hormone 98 pg/ml. He had a parathyroidectomy in 1998 and 1999. X-rays of his hands and legs showed diffuse subcutaneous arteriolar calcification. Angiography revealed no local stenotic lesions. Despite intensive therapies including hyperbaric oxygen therapy, painful gangrene developed on his right big toe and the pain was so intense that he could not go to sleep in a supine position. We infused intravenous sodium thiosulfate (20 g) 3 times weekly, based on previous reports. Within 4 - 5 days, he experienced rapid and dramatic symptom relief. The score of the visual analogue pain scale improved from 10/10 - 2/10. The signs of ischemia, measured by transcutaneous partial oxygen pressure and thermography, improved significantly. During the infusion of sodium thiosulfate, the patient complained of nausea, vomiting and hyperosmia. These adverse symptoms were resolved after discontinuation of the infusion. Pain relief was sustained and he could walk after 2 weeks of infusion. Our case supports the use of sodium thiosulfate as a novel therapeutic choice for critical limb ischemia with severe vascular calcification in chronic HD patients.

Suppression of myofibrillar proteolysis in chick skeletal muscles by α-ketoisocaproate

We previously reported that L-leucine suppresses myofibrillar proteolysis in chick skeletal muscles. In the current study, we compared the effects of L- and D-enantiomers of leucine on myofibrillar proteolysis in skeletal muscle of chicks. We also assessed whether leucine itself or its metabolite, alpha-ketoisocaproate (alpha-KIC), mediates the effects of leucine. Food-deprived (24 h) chicks were orally administered 225 mg/100 g body weight L-leucine, D-leucine or alpha-KIC and were sacrificed after 2 h. L-Leucine administration had an obvious inhibitory effect on myofibrillar proteolysis (plasma N(tau)-methylhistidine concentration) in chicks while D-leucine and alpha-KIC were much more effective. We also examined the expression of the proteolytic-related genes (ubiquitin, proteasome, m-calpain and cathepsin B) by real-time PCR of cDNA in chick skeletal muscles. Ubiquitin mRNA expression was decreased by D-leucine and alpha-KIC but not L-leucine. Proteasome and m-calpain mRNA expressions as well as cathepsin B mRNA expression were likewise decreased by L-leucine, D-leucine and alpha-KIC. These results indicate that D-leucine and alpha-KIC suppress proteolytic-related genes, resulting in an decrease in myofibrillar proteolysis while L-leucine is much less effective in skeletal muscle of chicks, may be explain by conversion of D-leucine to alpha-KIC.

A key role for the subunit SUR2B in the preferential activation of vascular KATP channels by isoflurane

BACKGROUND AND PURPOSE

It has been postulated that isoflurane, a volatile anaesthetic, produces vasodilatation through activation of ATP-sensitive K+ (KATP) channels. However, there is no direct evidence for the activation of vascular KATP channels by isoflurane. This study was conducted to examine the effect of isoflurane on vascular KATP channels and compare it with that on cardiac KATP channels.

EXPERIMENTAL APPROACH

Effects of isoflurane on KATP channels were examined in aortic smooth muscle cells and cardiomyocytes of the mouse using patch clamp techniques. Effects of the anaesthetic on the KATP channels with different combinations of the inward rectifier pore subunits (Kir6.1 and Kir6.2) and sulphonylurea receptor subunits (SUR2A and SUR2B) reconstituted in a heterologous expression system were also examined.

KEY RESULTS

Isoflurane increased the coronary flow in Langendorff-perfused mouse hearts in a concentration-dependent manner, which was abolished by 10 microM glibenclamide. In enzymically-dissociated aortic smooth muscle cells, isoflurane evoked a glibenclamide-sensitive current (i.e. KATP current). In isolated mouse ventricular cells, however, isoflurane failed to evoke the KATP current unless the KATP current was preactivated by the K+ channel opener pinacidil. Although isoflurane readily activated the Kir6.1/SUR2B channels (vascular type), the volatile anesthetic could not activate the Kir6.2/SUR2A channels (cardiac type) expressed in HEK293 cells. Isoflurane activated a glibenclamide-sensitive current in HEK293 cells expressing Kir6.2/SUR2B channels.

CONCLUSION AND IMPLICATIONS

Isoflurane activates KATP channels in vascular smooth muscle cells and produces coronary vasodilation in mouse hearts. SUR2B may be important for the activation of vascular-type KATP channels by isoflurane.