Effects of heat exposure in the absence of hyperthermia on power output during repeated cycling sprints.

The aim of this study was to investigate the effects of heat exposure in the absence of hyperthermia on power output during repeated cycling sprints. Seven males performed four 10-s cycling sprints interspersed by 30 s of active recovery on a cycle ergometer in hot-dry and thermoneutral environments. Changes in rectal temperature were similar under the two ambient conditions. The mean 2-s power output over the 1st-4th sprints was significantly lower under the hot-dry condition than under the thermoneutral condition. The amplitude of the electromyogram was lower under the hot-dry condition than under the thermoneutral condition during the early phase (0-3 s) of each cycling sprint. No significant difference was observed for blood lactate concentration between the two ambient conditions. Power output at the onset of a cycling sprint during repeated cycling sprints is decreased due to heat exposure in the absence of hyperthermia.

Effects of resistive load on performance and surface EMG activity during repeated cycling sprints on a non-isokinetic cycle ergometer.

OBJECTIVES: To determine the effects of resistive load on performance and surface electromyogram (SEMG) activity during repeated cycling sprints (RCS) on a non-isokinetic cycle ergometer. METHODS: Participants performed two RCS tests (ten 10-second cycling sprints) interspersed with both 30- and 360-second recovery periods under light (RCS(L)) and heavy load conditions (RCS(H)) in a random counterbalanced order. Recovery periods of 360 seconds were set before the fifth and ninth sprints. RESULTS: In the 9th and 10th sprints, the values of peak power output divided by body mass were significantly higher in RCS(H) than in RCS(L). Changes in blood lactate concentration were not different between the two conditions. In RCS(L), the root mean square calculated from the SEMG was significantly lower in the ninth sprint than in the first sprint, but there were no differences between the root mean square in the first sprint and that in the ninth sprint in RCS(H). CONCLUSIONS: During RCS on a non-isokinetic cycle ergometer, performance and SEMG activity are influenced by resistive load. It is thought that regulation of skeletal muscle recruitment by the central nervous system is associated with fatigue during RCS with a light resistive load.

[How to protect the surgeons' faces against spurting blood from the ascending aorta].

The blood spurting from the ascending aorta is uncomfortable for cardiac surgeons. To protect the surgeons' faces from this spurting blood, we use a longitudinal half of a plastic bottle, which is semi see-through. While the assistant is holding this device above the ascending aorta, the surgeons can proceed the operation with good surgical view.

Measurement of axial phase difference of density fluctuations owing to spontaneously excited waves by using microwave reflectometer on GAMMA 10/PDX.

In the GAMMA 10/PDX tandem mirror, plasma with strong ion-temperature anisotropy is produced by using the ion cyclotron range of frequency waves. This anisotropy of ion temperature causes several Alfvén-Ion-Cyclotron (AIC) waves to spontaneously excite in the frequency range just below the ion cyclotron frequency. In addition, difference-frequency (DF) waves are excited in the radial inner region of the plasma by wave-wave coupling among the AIC waves. The radial density profiles were measured at multi-axial positions using a frequency-modulation reflectometer with an axial array of microwave antennas, and an axial variation of the density was found to be significant. In addition, a relative phase difference of the DF wave between axially separated two points was first obtained by finely choosing the probing frequency of the reflectometers with a maximum coherence used as a measure, indicating that the DF wave is a propagating wave, while the pump AIC waves are standing waves in the axial region of measurement.

Development of visual cells in the Pacific bluefin tuna Thunnus orientalis.

The development of rod and cone photoreceptor cells was investigated in the retinas of Pacific bluefin tuna larvae and juveniles, using RET-P1 monoclonal antibody labeling to identify photoreceptors. At 60 h after hatching, which was about when feeding began, opsin (presumably green opsin (Rh2)) was expressed in the outer segments of cone cells. At 15 days after hatching (dah), although many labeled cone cells were observed in the dorsal retina, the same type of cone cells had partially appeared in the ventral retina. The presence of rod cell bodies was confirmed by the expression of Rh1 opsin at 15 dah. At 21 dah, the presence of outer segments of rod cells was confirmed by the expression of Rh1 opsin and by morphology. The observations suggest that the cone cells were substantially operable upon the development of their outer segment at around the beginning of the post-larval stage, and the rod cells began to function at around 15 to 21 dah, before and during metamorphosis.

Effects of sodium bicarbonate ingestion on hyperventilation and recovery of blood pH after a short-term intense exercise.

To determine the relationship between hyperventilation and recovery of blood pH during recovery from a heavy exercise, short-term intense exercise (STIE) tests were performed after human subjects ingested 0.3 g.kg(-1) body mass of either NaHCO3 (Alk) or CaCO3 (Pla). Ventilation (VE)-CO2 output (VCO2) slopes during recovery following STIE were significantly lower in Alk than in Pla, indicating that hyperventilation is attenuated under the alkalotic condition. However, this reduction of the slope was the result of unchanged VE and a small increase in VCO2. A significant correlation between VE and blood pH was found during recovery in both conditions. While there was no difference between the VE-pH slopes in the two conditions, VE at the same pH was higher in Alk than in Pla. Furthermore, the values of pH during recovery in both conditions increased toward the preexercise levels of each condition. Thus, although VE-VCO2 slope was decreased under the alkalotic condition, this could not be explained by the ventilatory depression attributed to increase in blood pH. We speculate that hyperventilation after the end of STIE is determined by the VE-pH relationship that was set before STIE or the intensity of the exercise performed.

Relationship between hyperventilation and excessive CO2 output during recovery from repeated cycling sprints.

The purpose of the present study was to examine whether excessive CO2 output (VCO2excess) is dominantly attributable to hyperventilation during the period of recovery from repeated cycling sprints. A series of four 10-sec cycling sprints with 30-sec passive recovery periods was performed two times. The first series and second series of cycle sprints (SCS) were followed by 360-sec passive recovery periods (first recovery and second recovery). Increases in blood lactate (DeltaLa) were 11.17+/-2.57 mM from rest to 5.5 min during first recovery and 2.07+/-1.23 mM from the start of the second SCS to 5.5 min during second recovery. CO2 output (VCO2) was significantly higher than O2 uptake (VO2) during both recovery periods. This difference was defined as VCO2excess. VCO2excess was significantly higher during first recovery than during second recovery. VCO2excess was added from rest to the end of first recovery and from the start of the second SCS to the end of second recovery (CO2excess). DeltaLa was significantly related to CO2excess (r=0.845). However, ventilation during first recovery was the same as that during second recovery. End-tidal CO2 pressure (PETCO2) significantly decreased from the resting level during the recovery periods, indicating hyperventilation. PETCO2 during first recovery was significantly higher than that during second recovery. It is concluded that VCO2excess is not simply determined by ventilation during recovery from repeated cycle sprints.

Effects of submaximal cycling at different exercise intensities on maximal isometric force output of the non-exercised elbow flexor muscles.

The purpose of this study was to examine the effects of submaximal cycling at different exercise intensities on maximal isometric force output of the non-exercised elbow flexor muscles after the cycling. A total of 8 healthy young men performed multiple maximal voluntary contractions by the right elbow flexion before, immediately after, 5 min after, and 10 min after a 6-min submaximal cycling at ventilatory threshold (LI), 70% [Formula: see text] (MI), and 80% [Formula: see text] (HI) with both arms relaxed in the air. Force and surface electromyogram (EMG) of the right biceps brachii muscle during the multiple MVCs, blood lactate concentration ([La]), cardiorespiratory responses, and sensations of fatigue for legs (SEF-L) were measured before, immediately after, 5 min after, and 10 min after the submaximal cycling with the three different exercise intensities. Immediately after the submaximal cycling, [La], cardiorespiratory responses, and SEF-L were enhanced in proportion to an increase in exercise intensity of the cycling. Changes in force and EMG activity during the multiple MVCs were not significantly different across the three conditions. The findings imply that group III/IV muscle afferent feedback after the submaximal cycling does not determine the magnitude of MVC force loss of the non-exercised upper limb muscles.

Successful Heart Transplantation After Desensitization in a Patient With Extremely High Panel-Reactive Antibody Levels and Pretransplant Donor-Specific Antibody: A Case Report.

Elevated panel-reactive antibody (PRA) levels serve as a significant risk factor for allograft survival and episodes of rejection after heart transplantation (HTX). Patients with high PRA levels tend to show expressions of donor-specific human leukocyte antigen antibodies (DSA), which can cause catastrophic hyperacute rejection after HTX. Therefore, such highly sensitized patients are required to undergo strategic perioperative desensitization therapy. We describe a successful HTX after desensitization in a patient with extremely high PRA levels and pretransplant DSA positivity.

Immunological Response of Pigs to Human Cells, Including Issues Such as the Production of Natural Antibodies in Newborns.

Pigs have recently become very popular for use not only in xenotransplantation field, but in regeneration studies as well, sometimes with pigs being used as the scaffold. We have already presented our findings related to the pig immune system against human cells, including the complement systems, natural antibodies (NAs), and NK cells. In this study, we investigated the pig innate immunological reaction against human cells further. Our investigations included issues such as the production of NAs in newborns, day 0 and day 1, and sow colostrum. The alternative pathway for pig complement reacted with human cells, and pig NK cells and macrophages directly injured human aortic endothelial cells. Pig serum clearly contains the natural antibodies IgG and IgM to human peripheral blood mononuclear cells (PBMCs). Pig plasma from day 1 newborns contained almost the same levels of these natural antibodies to human PBMCs as those of sow plasma. On the other hand, pig plasma from day 0 newborns did not contain IgG and IgM to human PBMCs. In addition, sow colostrum clearly contained both IgG and IgM to human PBMCs. As expected, the pig innate immunity system reacted to human cells, including natural antibodies. However, the NAs of pigs, both IgM and IgG, against human cells do not exist in pig serum at day 0, but at day 1 and in mother's milk, indicating that NAs in newborns did not come from the placenta but from sow colostrum.

Relationship between oxygenation in inactive biceps brachii muscle and hyperventilation during leg cycling.

Inactive forearm muscle oxygenation has been reported to begin decreasing from the respiratory compensation point (RCP) during ramp leg cycling. From the RCP, hyperventilation occurs with a decrease in arterial CO2 pressure (PaCO2). The aim of this study was to determine which of these two factors, hyperventilation or decrease in PaCO2, is related to a decrease in inactive biceps brachii muscle oxygenation during leg cycling. Each subject (n = 7) performed a 6-min two-step leg cycling. The exercise intensity in the first step (3 min) was halfway between the ventilatory threshold and RCP (170+/-21 watts), while that in the second step (3 min) was halfway between the RCP and peak oxygen uptake (240+/-28 watts). The amount of hyperventilation and PaCO2 were calculated from gas parameters. The average cross correlation function in seven subjects between inactive muscle oxygenation and amount of hyperventilation showed a negative peak at the time shift of zero (r = -0.72, p<0.001), while that between inactive muscle oxygenation and calculated PaCO2 showed no peak near the time shift of zero. Thus, we concluded that decrease in oxygenation in inactive arm muscle is closely coupled with increase in the amount of hyperventilation.

Comparison of oxygen uptake at the onset of decrement-load and constant-load exercise.

The purpose of the present study was to examine whether the level of oxygen uptake (V(.)(O2) at the onset of decrement-load exercise (DLE) is lower than that at the onset of constant-load exercise (CLE), since power output, which is the target of V(.)(O2) response, is decreased in DLE. CLE and DLE were performed under the conditions of moderate and heavy exercise intensities. Before and after these main exercises, previous exercise and post exercise were performed at 20 watts. DEL was started at the same power output as that for CLE and power output was decreased at a rate of 15 watts per min. V(.)(O2) in moderate CLE increased at a fast rate and showed a steady state, while V(.)(O2) in moderate DLE increased and decreased linearly. V(.)(O2) at the increasing phase in DLE was at the same level as that in moderate CLE. V(.)(O2) immediately after moderate DLE was higher than that in the previous exercise by 98+/-77.5 ml/min. V(.)(O2) in heavy CLE increased rapidly at first and then slowly increased, while V(.)(O2) in heavy DLE increased rapidly, showing a temporal convexity change, and decreased linearly. V(.)(O2) at the increasing phase of heavy DLE was the same level as that in heavy CLE. V(.)(O2) immediately after heavy DLE was significantly higher than that in the previous exercise by 156+/-131.8 ml/min. Thus, despite the different modes of exercise, V(.)(O2) at the increasing phase in DLE was at the same level as that in CLE due to the effect of the oxygen debt expressed by the higher level of V(.)(O2) at the end of DLE than that in the previous exercise.

Excessive oxygen uptake during exercise and recovery in heavy exercise.

The aim of this study was to determine whether excessive oxygen uptake (Vo2) occurs not only during exercise but also during recovery after heavy exercise. After previous exercise at zero watts for 4 min, the main exercise was performed for 10 min. Then recovery exercise at zero watts was performed for 10 min. The main exercises were moderate and heavy exercises at exercise intensities of 40 % and 70 % of peak Vo2, respectively. Vo2 kinetics above zero watts was obtained by subtracting Vo2 at zero watts of previous exercise (DeltaVo2). Delta Vo2 in moderate exercise was multiplied by the ratio of power output performed in moderate and heavy exercises so as to estimate the Delta Vo2 applicable to heavy exercise. The difference between Delta Vo2 in heavy exercise and Delta Vo2 estimated from the value of moderate exercise was obtained. The obtained Vo2 was defined as excessive Vo2. The time constant of excessive Vo2 during exercise (1.88+/-0.70 min) was significantly shorter than that during recovery (9.61+/-6.92 min). Thus, there was excessive Vo2 during recovery from heavy exercise, suggesting that O2/ATP ratio becomes high after a time delay in heavy exercise and the high ratio continues until recovery.

Effects of rate of decrease in power output in decrement-load exercise on oxygen uptake.

The purpose of this study was to examine how oxygen uptake (Vo2) in decrement-load exercise (DLE) is affected by changing rate of decrease in power output. DLE was performed at three different rates of decrease in power output (10, 20 and 30 watts.min(-1): DLE10, DLE20 and DLE30, respectively) from power output corresponding to 90 % of peak Vo2. Vo2 exponentially increased and then decreased, and the rate of its decrease was reduced at low power output. The values of Vo2 in the three DLE tests were not different for the first 2 min despite the difference in power output. The relationship between Vo2 and power output below 50 watts was obtained as a slope to estimate excessive Vo2 (ex-Vo2) above 50 watts. The slopes were 10.0+/-0.9 for DLE10, 9.9+/-0.7 for DLE20 and 10.2+/-1.0 ml.min(-1).watt(-1) for DLE30. The difference between Vo2 estimated from the slope and measured Vo2 was defined as ex-Vo2. The peak value of ex-Vo2 for DLE10 (189+/-116 ml.min(-1)) was significantly greater than those for DLE20 and for DLE30 (93+/-97 and 88+/-34 ml.min(-1)). The difference between Vo2 in DLE and that in incremental-load exercise (ILE) below 50 watts (DeltaVo2) was greater in DLE30 and smallest in DLE10. There were significant differences in DeltaVo2 among the three DLE tests. The values of DeltaVo2 at 30 watts were 283+/-152 for DLE10, 413+/-136 for DLE20 and 483+/-187 ml.min(-1) for DLE30. Thus, a faster rate of decrease in power output resulted in no change of Vo2 at the onset of DLE, smaller ex-Vo2 and greater DeltaVo2. These results suggest that Vo2 is disposed in parallel in each motor unit released from power output or recruited in DLE.

Liver Failure From Ultra-Short Bowel Syndrome on the Intestinal Transplant Waiting List: A Retrospective Study.

BACKGROUND: Patients with intestinal failure (IF) are candidates for intestinal transplantation (ITx). In Japan, these patients have few opportunities to undergo cadaveric ITx because of low rates of organ donation. The donor criteria and recipient priority for ITx are still unknown. We reviewed our cases of IF to investigate which patients should be prioritized for ITx. METHODS: Patients with IF who were registered as candidates for cadaveric ITx between January 2010 and November 2015 in our institute were included in this retrospective study. Their data were gathered from their charts and analyzed. RESULTS: Five patients were included. Their primary diseases included total colon aganglionosis (n = 1), chronic idiopathic intestinal pseudo-obstruction syndrome (n = 2), superior mesenteric vein embolization (n = 1), and graft loss after ITx (n = 1). Two patients died of liver failure (LF) during the waiting period. The remaining three are now alive and waiting for transplantation. The lengths of the remaining intestine were more than 20 cm in living cases but less than 20 cm in fatal cases. In the fatal cases, they had several episodes of catheter-related blood stream infection, which caused LF and acute renal failure. CONCLUSIONS: We identified two patients with less than 20 cm residual small bowel who died after acute deterioration of liver function. Patients with ultra-short bowel could have a higher risk of LF. Therefore, they should be referred as soon as possible to a specialized hospital where ITx is a choice of treatment for IF.

Expression of a Synthetic Gene of CTDM by Transgenic Animals.

BACKGROUND: The purpose of this study was to produce molecules that can precisely regulate the complement and coagulation system and to assess the expression of such molecules in transgenic animals. METHODS: The CTDM gene, which is composed of the delta-1-99 amino acid (aa) C1-INH, EGF domain 4-6 of thrombomoduline (TM), short consensus repeat (SCR) 2-4 of DAF(CD55), and SCR 2-4 of MCP(CD46) was established. The codon usage for expression in mammals was adopted. The cDNA of CTDM was subcloned into the pCPI site (the human insulin promoter and a cytomegalovirus enhancer). pCPI-CTDM was transfected into pig endothelial cells (PEC). The expression of the molecule was clearly assessed by means of flow cytometry. RESULTS: BD3F1 female mice were induced to superovulate and were then crossed with BD3F1 males. Micro-injection and embryo transfer were performed by standard methods, thus generating transgenic mice that express CTDM. The mice carried the CTDM plasmid, as verified by PCR. Tissue expression levels in transgenic mouse lines generated with the constructs were follows: pancreas, 1.0; brain, 5.4; thymus, 0.3; heart, 0.2; lung, 1.2; liver, 0.1; kidney, 0.1; intestine, 0.4; and spleen, 1.6. A naive control mouse was also analyzed in the exact manner as for the transgenic mice. CONCLUSIONS: A synthetic CTDM gene with codon usage optimized to the mammalian system represents a critical factor in the development of transgenic animals.

Studies of Pig Complement: Measurement of Pig CH50, ACH50, and Components.

BACKGROUND: On the basis of a comparison of the hemolytic complement titer in pigs with that in humans, the complement system of pigs was investigated. The response of innate immunity, such as the natural antibodies, against humans was also examined. METHODS: Hemolytic complement activity of pig serum was measured with the use of a microtitration technique. CH50 was determined according to the method of Mayer. ACH50 was assayed according to the methods of Platts-Milles and Ishizaka. Hemolytic activities of C1, C4, C2, C3, C5, C8, and C9 were estimated through the use of intermediate cells and reagents, as described previously. In addition, the pig natural anti-human antibody was studied with the use of human peripheral blood mononuclear cells (PBMCs). Human PBMCs were stained with 5% pig serum, followed by staining with fluorescein isothiocyanate-labeled goat anti-pig IgG and IgM. The resulting stained cells were quantified by use of a FACScalibur system. The alternative pathway of pig complement was also measured with the use of human erythrocytes and normal pooled pig serum with or without Mg(++)EGTA. RESULTS: Both the CH50 and ACH50 titers were lower than those of humans. Concerning the components, except for C3, each component, that is, C1, C4, C2, C5, C8, and C9, was also lower than that of humans, based on measured values for human complement components. Pig serum clearly contains natural antibodies, IgG and IgM, to human PBMCs. The alternative pathway of pig complement reacted with human erythrocytes. CONCLUSIONS: As a whole, pig innate immunity, the complement system and natural antibody, recognizes the surfaces of human cells.

Supplemental Analysis for N-linked Sugars in Adult Pig Islets.

The pig pancreas is considered to be one of the most suitable sources of islets for clinical xenotransplantation. However, after producing α1-3galactosyltransferase knockout pigs, most of the organs of these pigs showed less antigenicity to the human body. Wild-type adult pig islets (APIs) that originally produced negligible levels of α-Gal, different from neonatal porcine islet-like cell clusters, showed a clear antigenicity to human serum. Concerning the so-called non-Gal epitopes, many studies related to glycoproteins and glycolipids are ongoing in efforts to identify them. However, our knowledge of non-Gal glycoantigens remains incomplete. In our previous study, N-glycans were isolated from APIs, and the structures of 28 of the N-glycans were detected. In this study, to identify additional structures, further analyses were performed by liquid chromatography-mass spectrometry (LC-MS). N-glycans were isolated from APIs by the method described by O'Neil et al with minor modifications and LC-MS-based structural analyses were then performed. The detected N-glycan peaks in the LC-MS spectra were selected using the FLexAnalysis software program and the structures of the glycans were predicted using the GlyocoMod Tool. The API preparation contained 11 peaks and 16 structures were then nominated as containing N-linked sugars. Among them, 5 sulfated glycans were estimated, confirming the existence of sulfate structures in N-glycans in API. In addition, these data may supplement several N-glycan structures that contain two deoxyhexose units, such as fucose, to our previous report. The data herein will be helpful for future studies of antigenicity associated with API.

Knockout of Cytidine Monophospho-N-Acetylneuraminic Acid (CMP-NeuAc) Hydroxylase From Porcine Endothelial Cells by a CRISPR System.

BACKGROUND: We attempted to knock out the expression of Hanganutziu-Deicher (H-D) antigens through the use of a CRISPR (clustered regulatory interspaced short palindromic repeat)/Cas9 system for pig cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH). METHODS: Plasmids expressing hCas9 and sgRNA for pCMAH were prepared by ligating oligos into the BbsI site of pX330. The N-terminal and C-terminal EGFP coding regions overlapping 482 bp were PCR-amplified and placed under a ubiquitous CAG promoter. The approximately 400-bp genomic fragments containing the sgRNA target sequence of pCMAH were placed into the multi-cloning sites flanked by the EGFP fragments. The pCAG-EGxxFP-target was mixed with pX330 with/without the sgRNA sequences and then introduced into HEK293T cells. RESULTS: Four oligos and primers, gSO1, gSO3, gSO4, and gSO8, were nominated from 8 candidates. Among them, gSO1 showed the best efficiency. Pig endothelial cells (PECs) from an α-Gal knockout pig were then used to examine the changes in the expression of the H-D antigen by the knockout of the CMAH genome by the pX330-gS01. CONCLUSIONS: Changes in the expression of the H-D antigen in the PECs with the CRISPR (gS01) were clear in comparison with those in the parental cells, on the basis of FACS analysis data. The expression of the H-D antigen can be knocked out by use of the CRISPR system for pCMAH, thus confirming that this system is a very convenient system for producing knockout pigs.

Disseminated Metastatic Tissue Calcification After Orthotopic Liver Transplantation: A Case Report.

BACKGROUND: Hypercalcemia has been observed in patients after liver transplantation. However, it is rare that the hypercalcemia induced disseminated tissue calcification and heart failure. CASE REPORT: We report a rare case of heart failure caused by disseminated metastatic tissue calcification that involved extensive progressive myocardial calcification after liver transplantation. A 20-year-old man with end-stage liver disease due to biliary atresia underwent ABO-incompatible living donor liver transplantation. After successful transplantation, he suffered from antibody-mediated rejection. Subsequently, ABO-matched cadaveric liver retransplantation was successfully performed. Hypercalcemia developed gradually following the second transplantation. His serum calcium level increased to 18.3 mg/dL with sudden onset of ventricular tachycardia. Although he was resuscitated with a cardiopulmonary support device, he died of heart and liver failure. Histopathologic examination revealed systemic disseminated metastatic tissue calcification, including massive myocardial calcification. CONCLUSION: Progressive worsening of hypercalcemia resulted in disseminated metastatic tissue calcification and massive metastatic myocardial calcification, which led to heart failure after liver transplantation. Because hypercalcemia after liver transplantation can cause fatal tissue calcification, early intervention for hypercalcemia should be considered.