Response of end tidal CO2 pressure to impulse exercise

The purpose of the present study was to examine how end tidal CO(2) pressure (PETCO(2)) is controlled in impulse exercise. After pre-exercise at 25 watts for 5 min, impulse exercise for 10 sec with 200 watts followed by post exercise at 25 watts was performed. Ventilation (VE) significantly increased until the end of impulse exercise and significantly re-increased after a sudden decrease. Heart rate (HR) significantly increased until the end of impulse exercise and then decreased to the pre-exercise level. PETCO(2) remained constant during impulse exercise. PETCO(2) significantly increased momentarily after impulse exercise and then significantly decreased to the pre-exercise level. PETCO(2) showed oscillation. The average peak frequency of power spectral density in PETCO(2) appeared at 0.0078 Hz. Cross correlations were obtained after impulse exercise. The peak cross correlations between VE and PETCO(2), HR and PETCO(2), and VE and HR were 0.834 with a time delay of -7 sec, 0.813 with a time delay of 7 sec and 0.701 with a time delay of -15 sec, respectively. We demonstrated that PETCO(2) homeodynamics was interactively maintained by PETCO(2) itself, CO(2) transportation (product of cardiac output and mixed venous CO(2) content) into the lungs by heart pumping and CO(2) elimination by ventilation, and it oscillates as a result of their interactions.

Radial incision and cutting method for refractory stricture after nonsurgical treatment of esophageal cancer

Strictures remaining after nonsurgical treatment for esophageal cancer are generally more refractory to endoscopic balloon dilation (EBD) when compared with anastomotic strictures. The aim of the present study was to evaluate the efficacy and safety of a radial incision and cutting (RIC) method for the treatment of refractory strictures after nonsurgical treatment of esophageal cancer. All subjects complained of grade 2 or worse dysphagia, even after at least 10 sessions of EBD. Between August 2009 and May 2012, eight consecutive patients with refractory esophageal stricture after nonsurgical treatments, including chemoradiotherapy (CRT) alone (n = 3), CRT followed by salvage endoscopic treatment (n = 3), or endoscopic submucosal dissection (ESD; n = 2), underwent the RIC procedure. After the RIC procedure, dysphagia in all the patients dramatically improved to grade 1 or 0 without any major complications; however, the long-term efficacy was unfavorable as only 37.5 % (3 /8) demonstrated adequate lumen patency at 3 months, and re-intervention was necessary in six patients (75 %).

Cinacalcet, a calcimimetic, prevents nonsteroidal antiinflammatory drug-induced small intestinal damage in rats

The extracellular calcium-sensing receptor (CaSR), a G protein-coupled cell receptor cloned from bovine parathyroid, has been demonstrated to play a regulatory role in various functions of the gastrointestinal tract. In the present study, we examined the effect of cinacalcet, a drug that acts as a calcimimetic through the allosteric activation of CaSR, on the loxoprofen-induced small intestinal lesions and investigated the mechanisms involved in the protective action. Male Sprague-Dawley rats were used without fasting. The animals were administered loxoprofen p.o. and euthanized 24 hours later and the intestinal mucosa was examined for lesions. Cinacalcet was given p.o. twice, 30 min before and 6 h after loxoprofen. Loxoprofen caused hemorrhagic lesions in the small intestine, accompanied by the upregulation of enterobacterial invasion, myeloperoxidase (MPO) activity and inducible nitric oxide synthase (iNOS)/tumor necrosis factor α (TNF-α) expression as well as the downregulation of Muc2 expression. Prior administration of cinacalcet dose-dependently and significantly reduced the severity of these lesions in response to loxoprofen, with concomitant suppression of the changes in bacterial invasion, iNOS/TNF-α as well as Muc2 expression, and myeloperoxidase activity. Cinacalcet also significantly reversed a decrease in mucus secretion and fluid secretion in the small intestine caused by loxoprofen, but had no effect on the intestinal hypermotility or prostaglandin E₂ deficiency caused by loxoprofen. These results suggest that cinacalcet protects the small intestine against loxoprofen-induced damage, and this effect may be functionally associated with an increase in fluid secretion and a reversal of downregulation of Muc2 expression caused by loxoprofen, resulting in suppression of bacterial invasion and iNOS/TNF-α expression, the major pathogenic events in nonsteroidal antiinflammatory drugs-induced small intestinal ulceration.

Lack of GPR40/FFAR1 does not induce diabetes even under insulin resistance condition

AIMS

G protein-coupled receptor/free fatty acid receptor 1 (GPR40/FFAR1 ) regulates free fatty acid-induced insulin secretion. This study has been performed to clarify whether or not loss of GPR40/FFAR1 function exacerbates diabetes, that is, whether GPR40 has an essential physiological role in the development of diabetes or not.

METHODS

We generated GPR40/FFAR1 knockout (KO) mice and analysed their phenotypes in vitro and in vivo under the condition of dietary or genetically induced insulin resistance.

RESULTS

GPR40/FFAR1 KO mice kept on a high-fat diet became obese, developed glucose intolerance to a similar degree as GPR40/FFAR1 wild-type (WT) mice. In addition, the phenotype of KO mice harbouring diabetogenic KK background genes showed glucose intolerance at a level similar to level for control KK mice. In both mouse models with insulin resistance, insulin secretion after oral glucose load and homeostasis model assessment-insulin resistance (HOMA-IR) did not change between GPR40/FFAR1 KO and WT mice. Although glucose-induced insulin secretion under high palmitate concentration was significantly lower in KO than in WT islets, pancreatic insulin content and insulin secretion stimulated with glucose alone were not different between KO and WT mice.

CONCLUSIONS

GPR40/FFAR1 has a major role in regulating fatty-acid-mediated insulin secretion, but the lack of GPR40/FFAR1 does not exacerbate glucose intolerance and insulin resistance induced by high-fat diet or diabetogenic KK gene. Our findings indicate that loss of GPR40/FFAR1 function does not play an important role in inducing or exacerbating diabetes.

Oscillation of oxygenation in skeletal muscle at rest and in light exercise

The aim of the present study was to compare the frequency of oxygenation determined in the vastus lateralis by near-infrared spectroscopy (NIRS) in light exercise with that at rest. A subject rested in a recumbent position for 5 min and changed body position to a sitting position on a cycle ergometer for 9 min. Then exercise with low intensity (work rate of 60% of maximal oxygen uptake) was carried out for 30 min. Total hemoglobin and myoglobin (THb/Mb) suddenly decreased after the start of exercise and gradually increased for 6 min. Oxygenated hemoglobin and myoglobin (Hb/MbO2) suddenly decreased and returned to a steady-state after the start of exercise. The difference between Hb/MbO2 and THb/Mb showed a sudden decrease and then a steady-state. This difference was analyzed by fast Fourier transform. The peak frequencies of the power spectrum density (PSD) were 0.0169 ± 0.0076 Hz at rest and 0.0117 ± 0.0042 Hz in exercise. The peak frequency of PSD was significantly decreased in exercise. In exercise, the range of frequencies was expanded. It is concluded that there are oscillations at rest as well as in exercise and that the frequency of peak PSD becomes lower in exercise than at rest.

Relationship between ventilation and predicted arterial CO2 pressure during recovery from an impulse-like exercise without metabolic acidosis

We investigated ventilation (V(.)E) control factors during recovery from light impulse-like exercise (100 watts) with a duration of 20 s. Blood ions and gases were measured at rest and during recovery. V(.)E, end tidal CO(2) pressure (PETCO(2)) and respiratory exchange ratio (RER) were measured continuously during rest, exercise and recovery periods. Arterial CO(2) pressure (PaCO(2) (pre) was estimated from PETCO(2) and tidal volume (V(T)). RER at 20 s of exercise and until 50 s during recovery was significantly lower than RER at rest. Despite no change in arterialized blood pH level, PaCO(2) (pre) was significantly higher in the last 10 s of exercise and until 70 s during recovery than the resting value. V(.)E increased during exercise and then decreased during recovery; however, it was elevated and was significantly higher than the resting value until 155 s (p<0.05). There was a significant relationship between V(.)E and PaCO(2) (pre) during the first 70 s of recovery in each subject. The results suggest that PaCO(2) drives V(.)E during the first 70 s of recovery after light impulse-like exercise. Elevated V(.)E in the interval from 70 s until 155 s during recovery might be due to neural factors.

Prospective study comparing the new sclerotherapy and hemorrhoidectomy in terms of therapeutic outcomes at 4 years after the treatment

PURPOSE

Recently, sclerotherapy using a new sclerosing agent (aluminum potassium sulfate and tannic acid) has become widespread in Japan as a treatment for hemorrhoids. In the present study, we investigated whether sclerotherapy or surgical therapy (hemorrhoidectomy) is superior in terms of the therapeutic outcomes at 4 years.

METHODS

We sent a questionnaire on symptoms and the degree of satisfaction to patients who underwent sclerotherapy or hemorrhoidectomy for grade 3 or 4 hemorrhoids in 2007, and compared the two therapies based on the responses, with respect to superiority of the therapeutic outcomes at 4 years. To identify the factors affecting the symptom-free and satisfaction rates, the univariate and multivariate analyses were performed for the following seven parameters: age, sex, degree of hemorrhoids, presence of external hemorrhoids, past history of treatment for hemorrhoids, number of hemorrhoids treated and the type of treatment.

RESULTS

Overall, 75 % of the patients (195/260) responded to the questionnaire. In this study, the symptom-free rates were 53 % (30/57 patients) in the sclerotherapy group and 80 % (111/138 patients) in the hemorrhoidectomy group, and the satisfaction rates were 70 % (40/57 patients) in the sclerotherapy group and 88 % (121/138 patients) in the hemorrhoidectomy group. The results revealed that the type of treatment was the only factor affecting these two outcomes.

CONCLUSIONS

Our results indicate that hemorrhoidectomy is superior to sclerotherapy. These findings may be useful in the treatment of hemorrhoid patients.

Comparison of oscillation of oxygenation in skeletal muscle between early and late phases in prolonged exercise

The aim of the present study was to compare the oscillations of oxygenation in skeletal muscle between early and late phases in prolonged exercise. During prolonged exercise at 60 % of peak oxygen uptake (V(.)o(2)) for 60 min and at rest, oxygenated hemoglobin/myoglobin (Hb/MbO(2)) and total Hb/Mb (THb/Mb) were determined by near-infrared spectroscopy in the vastus lateralis. Power spectra density (PSD) for the difference between Hb/MbO(2) and THb/Mb (-HHb/MbO(2): deoxygenation) was obtained by fast Fourier transform at rest, in the early phase (1-6 min) and in the late phase (55-60 min) in exercise. Peak PSD in the early phase was significantly higher than that at rest. There were at least three peaks of PSD in exercise. The highest peak was a band around 0.01 Hz, the next peak was a band around 0.04 Hz, and the lowest peak was a band around 0.06 Hz. PSD in the early phase was not significantly different from that in the late phase in exercise. Heart rate (HR) showed a continuous significant increase from 3 min in exercise until the end of exercise. Skin blood flow (SBF) around the early phase was significantly lower than that around the late phase. It was concluded that oscillation of oxygenation in the muscle oxygen system in the early phase is not different from that in the late phase in prolonged exercise despite cardiovascular drift.

Cellulitis lesions in broiler chickens are induced by Escherichia coli Vacuolating Factor (ECVF)

Escherichia coli Vacuolating Factor (ECVF) is a heat-labile, vacuolating cytotoxin produced by avian pathogenic E. coli (APEC) isolated from avian cellulitis lesions. In this report, we intend to demonstrate that purified ECVF induces the inflammatory process of cellulitis. Our group is the first to demonstrate the effect of ECVF in a histological analysis by in situ inoculation of broiler chickens with purified ECVF. The animals were inoculated with the APEC AC53 and with purified ECVF subcutaneously on their ventral surface (in the sternum region). The histological analysis showed different grades of an acute inflammatory response in the epidermis, dermis and panniculus. An increase in mRNA expression of the proinflammatory cytokine TNF-α was also demonstrated in the inflamed tissue. When ECVF was systemically administered, increased levels of TNF-α and IL-10 were observed in the serum. These results suggest that ECVF plays a key role in the inflammatory process associated with cellulitis that is mainly mediated by TNF-α. In addition, this inflammation can be downregulated by the anti-inflammatory cytokine IL-10.

Evaluation of strategies for the eradication of Pseudorabies virus (Aujeszky's disease) in commercial swine farms in Chiang-Mai and Lampoon Provinces, Thailand, using a simulation disease spread model

Several strategies for eradicating Pseudorabies virus (Aujeszky's disease) in Chiang-Mai and Lampoon Provinces, Thailand, were compared using a computer simulation model, the North American Animal Disease Spread Model (NAADSM). The duration of the outbreak, the number of affected herds and the number of destroyed herds were compared during these simulated outbreaks. Depopulation, zoning for restricted movement and improved detection and vaccination strategies were assessed. The most effective strategies to eradicate Pseudorabies as per the findings from this study are applying depopulation strategies with MOVEMENT RESTRICTIONS in 3-, 8- and 16-km ZONES surrounding infected herds and enhancing the eradication with vaccination campaign on 16-km radius surrounding infected herds.

Effect of arterial carbon dioxide on ventilation during recovery from impulse exercises of various intensities

To determine that whether arterial carbon dioxide (PaCO₂) affects ventilation (VE) during recovery from impulse-like exercises of various intensities, subjects performed four impulse-like tests with different workloads. Each test consisted of a 20-sec impulse-like exercise at 80 rpm and 60-min recovery. Blood samples were collected at rest and during recovery to measure blood ions and gases. VE was measured continuously during rest, exercise and recovery periods. A significant curvilinear relationship was observed between VE and pH during recovery from the 300- and 400-watt tests in all subjects. VE was elevated during recovery from the 100-watt test despite no change in any of the humoral factors. Arterialized carbon dioxide (PaCO₂) kinetics showed fluctuation, being increased at 1 min and decreased at 5 min during recovery, and this fluctuation was more enhanced with increase in exercise intensity. There was a significant relationship between VE and PaCO₂ during recovery from the 300- and 400-watt tests in all subjects. The results of the present study demonstrate that pH and neural factors drive VE during recovery from impulse-like exercise and that fluctuation in PaCO₂ controls VE as a feedback loop and this feedback function is more enhanced as the work intensity increases.