Several studies on alcohol and gastric emptying using the ¹³C breath test showed that alcohol consumption delayed gastric emptying of meals in healthy male subjects. However, they did not employ female subjects, and the retention time of alcoholic beverages in the stomach has not been examined, yet. We examined the retention time (= gastric emptying rate) of alcoholic beverages in the stomach in healthy male and female subjects. We also examined whether the congeners (nonalcoholic components) of red wine have any effect on gastric emptying. The retention time of 60 mL of red wine, vodka, congeners of red wine, or mineral water, was measured using a ¹³C labeled acetic acid breath test. In male subjects, the retention time of wine and vodka was significantly longer than that of congeners and mineral water. In female subjects, although the ¹³C content in the breath was slightly but significantly decreased by wine and congeners, but not by vodka, and the parameters for gastric emptying did not differ significantly among the 4 drinks. That is, alcohol hardly influenced the retention time in female subjects. In conclusion, there are sex differences in the gastric emptying rate of alcohol.

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The establishment of cartilage regenerative medicine has been an important issue in the clinical field, because cartilage has the poor ability of self-repair. Currently, tissue engineering using autologous chondrocytes has risen, but we should investigate more appropriate cell sources that can be obtained without any quantitative limitation. In this study, we focused on induced pluripotent stem (iPS) cells, in which the ethical hurdle does not seem higher than that of embryonic stem cells. Mouse iPS cells were transplanted into the mouse joint defect model of the knee. Strains of the transplants and hosts were arranged to be either closest (homology 75% in genetic background) or identical (100%). For transplantation, we embedded the iPS cells within the collagen hydrogel in order to obtain the effective administration of the cells into defects, which induced the differentiation of the iPS cells. At 8 weeks of transplantation, although the iPS cells with a 75% homology to the host in the genetic background tended to form teratoma, those of 100% showed a joint regeneration. GFP immunohistochemistry proved that the transplanted iPS cells were responsible for the bone and cartilage repair. Taking these results together, the iPS cells are regarded as a promising cell source for the cartilage tissue engineering.

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MicroRNAs (miRNAs) are endogenous small RNAs of 18–23 nucleotides that regulate gene expression. Recently, plasma miRNAs have been investigated as biomarkers for various diseases. In the present study, we explored whether miRNA expression profiling of various muscle cells may be useful for the diagnosis of various diseases involving muscle necrosis. miRNA expression profiling was assessed by miRNA array and real-time reverse-transcriptase polymerase chain reaction by using a reverse primer of a stem loop structure. Profiling of various muscle cells of mouse, including cardiac muscles, skeletal muscles, and vascular and visceral smooth muscles, indicated that profiling of miR-1, miR-133a, miR-133b, miR-145, miR-206, miR-208a, miR-208b, and miR499 were adequate to discriminate muscle cells. miR-145 was remarkably highly expressed in smooth muscles. miR-208a and miR-499 were highly expressed in cardiomyocytes. miR-133a was highly expressed in fast-twitch skeletal muscles. miR-206 and miR-208b were expressed in the slow-twitch skeletal muscles, and they can likely discriminate fast- and slow-twitch types of skeletal muscle cells. We observed that brown fat adipose cells had an miRNA expression profile very similar to those of skeletal muscle cells in the mouse. Plasma concentrations of miR-133a and miR-145 were extremely useful in diagnosing skeletal muscle necrosis in a mouse model of Duchenne muscular dystrophy and colon smooth muscle necrosis in a rat ischemic colitis model, respectively. In the present study, we investigated the miRNA expression profiles of various muscular tissues. Our results suggest that expression profiling would be useful for the diagnosis of various diseases such as muscular necrosis.

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Green tea and tea catechins, especially (−)-epigallocatechin gallate (EGCG), have been shown to have various health benefits including anti-cancer, anti-metastasis, and anti-cardiovascular disease effects. Our previous studies demonstrated that three plasma proteins, fibronectin, histidine-rich glycoprotein, and fibrinogen were bound by EGCG, and that one specific domain in fibronectin was responsible for its binding interaction with EGCG. Fibrinogen consists of 6 chains linked by the disulfide bonds of two each of the α-, β-, and γ-chains. The present study examined whether fibrinogen had a specific domain interacting with EGCG. The results of affinity chromatography under reducing conditions demonstrated that each of the α-, β-, and γ-subunit chains of fibrinogen was bound by EGCG. We also demonstrated that several peptides generated by treatment with cyanogen bromide or thermolysin were bound by EGCG. The amino acid sequences analyzed revealed that these peptides included those derived from the α-, β-, and γ-chains of fibrinogen. EGCG inhibited the spreading of mouse metastatic LL2-Lu3 lung cancer cells on the fibrinogen substratum, which suggested an impairment in the interaction between cancer cells and fibrinogen. Since the interaction between cancer cells and fibrinogen plays an important role in metastasis, the present results suggest, at least partially, that EGCG inhibited metastasis in the mouse models reported previously by inhibiting such an interaction.

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Pirfenidone (PFD) is a novel anti-fibrotic agent that targets TGFβ. However, the mechanisms underlying its renoprotective properties in hypertension-induced renal injury are poorly understood. We investigated the renoprotective properties of PFD and clarified its renoprotective mechanisms in a rat hypertension-induced renal injury model. Dahl salt-sensitive rats were fed a high-salt diet with or without 1% PFD for 6 weeks. During the administration period, we examined the effects of PFD on blood pressure and renal function. After the administration, the protein levels of renal TGFβ, Smad2/3, TNFα, MMP9, TIMP1, and catalase were examined. In addition, total serum antioxidant activity was measured. Compared to untreated rats, PFD treatment significantly attenuated blood pressure and proteinuria. Histological study showed that PFD treatment improved renal fibrosis. PFD may exert its anti-fibrotic effects via the downregulation of TGFβ-Smad2/3 signaling, improvement of MMP9/TIMP1 balance, and suppression of fibroblast proliferation. PFD treatment also increased catalase expression and total serum antioxidant activity. In contrast, PFD treatment did not affect the expression of TNFα protein, macrophage or T-cell infiltration, or plasma interleukin 1β levels. PFD prevents renal injury via its anti-fibrotic and anti-oxidative stress mechanisms. Clarifying the renoprotective mechanisms of PFD will help improve treatment for chronic renal diseases.

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The purpose of this study was to determine the physiological and biochemical properties of hindlimb muscles after hypoventilation (HPO) induced by bilateral phrenic nerve denervation. Male Wistar rats (10 weeks-old) underwent HPO by the phrenic nerve denervation at the cervical level or sham surgery. Analyses were performed 4, 8, and 12 weeks after the surgery. The myosin heavy chain (MHC) isoform profile and in vitro isometric contractile properties of the soleus (SOL) and extensor digitrum longus muscles (EDL) were analyzed. From the postoperative period, HPO induced characteristic changes in SpO₂ such as hypoventilation disorder. After 12 weeks, significant increases in MHC1 and significant decreases in MHC2a were observed in the MHC isoform composition in SOL. Moreover, significant increases in MHC2a and significant decreases in MHC2b were also observed in the MHC isoform composition in EDL muscles in the HPO compared with sham (SHM) group. In our study, the tidal volume after unilateral phrenic nerve denervation decreased by approximately 12%, and that after bilateral phrenic nerve denervation decreased by approximately 35%. We concluded that the reduction in behavioral activity levels in the HPO group may have resulted in changes of the peripheral skeletal muscles as a result of disuse atrophy.

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Adult rat dorsal root ganglion (DRG) neurons cultured in the presence of 100-ng/mL NGF were reported to show spontaneous action potentials in the cell-attached recording. In this study, underlying mechanisms were examined in the whole-cell and outside-out voltage clamp recording. In 75% neurons with on-cell firing, transient inward current spikes were repetitively recorded in the voltage clamp mode at −50 mV in the whole-cell configuration (named “I_sp”). I_sp with stable amplitudes occurred in an all-or-none fashion, and was abolished by TTX (< 100 nM), lidocaine (< 1 mM) and a reduction of extracellular Na⁺ (154 to 100 mM) in an all-or-none fashion, suggesting that I_sp reflects spontaneous dicharges occurring at the loosely voltage-clamped regions. I_sp was also observed in the excised outside-out patches and the kinetics and the sensitivity to TTX and lidocaine resembled those in the whole-cell. Spontaneous action potentials were also recorded in the current clamp mode. Small subthreshold spikes often preceded the action potentials. When the localized discharge affected a whole-somatic membrane potential to overcome a threshold, the action potential generated. These results indicate that the triggering sources of the action potential exist in the somatic membrane itself in NGF-treated DRG neurons.

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