• Title/Summary/Keyword: pH stimulation

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Effects of pH Early Postmortem on Meat Quality in Beef Longissimus

  • Hwang, I.H.;Tompson, J.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.8
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    • pp.1218-1223
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    • 2003
  • The effects of type (high and low voltages) and time (3, 40 and 60 min postmortem) of stimulation on drip loss and meat color at 24 h post-mortem were determined on M. longissimus dorsi of 38 crossbred steers and heifers. In addition, the effect of pH early postmortem (70 min postmortem) on the rate and extend of meat tenderization was examined. Either high or low voltage stimulation at 3 min showed a tendency for faster pH decline (p=0.052) and higher drip loss (p=0.08), and improved the color dimensions of L*, a* and b* (p<0.01), compared to stimulation at 40 min. This was equivalent to approximately one unit of an AUSMEAT color chip. On the other hand, although there were significant differences in pH decline between high voltage stimulation at 40 and 60 min, and between low voltage stimulation at 40 min and control sides, drip loss and meat color did not differ significantly (p>0.05). The results suggested that early application of stimulation, regardless of type of stimulation, improved overall meat color at 24 h postmortem through its effect on faster glycolysing rate. However, if the pH decline was moderate, the benefit of electrical stimulation on meat color was not apparent. An intermediate pH decline resulted in the lowest shear force. Due to differential ageing rates the optimum pH at 70 min postmortem increased with ageing time from 5.96, 6.07, 6.12 and 6.14 for 1, 3, 7 and 14 days postmortem, respectively. This implied that a small difference in the rate of pH decline was important, especially carcasses stimulated for very early postmortem, and the optimum rate of pH decline varied with intended ageing period. The study suggests that the beneficial or adverse effects of electrical stimulation on drip loss, meat color and tenderness is determined by the rate of pH decline, rather than by stimulation treatment and time of application per se.

Effect of pH Stimulation on Acrosome Reaction of Bovine Spermatozoa (pH 자극이 소 정자의 첨모반응에 미치는 영향)

  • 박영식;임경순
    • Korean Journal of Animal Reproduction
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    • v.15 no.3
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    • pp.195-199
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    • 1991
  • This study was carried out ot investigate effect of pH stimulation on acrosome reaction of bovine spermatozoa. The results obtained were as follows : 1. When sperm was sequentially washed with SHP solution of pH 7.4, 7.7 and 7.4 and incubated in mTALP solution of pH 7.4 for 120min, 15, 30, 60 and 120min incubations showed significantly(p<0.05) higher sperm acrosome reaction rate than 0 min. 2. When sperm was sequentially washed with SHP solution of pH 7.4, 8.0 and 7.4 and incubated in mTALP solution of pH 7.4 for 15 minutes, sperm acrosome reaction rate was significantly(p<0.01) increased until 9 min. Incubation, but not increased thereafter. 3. When sperm were separately washed with SHP solutions of pH 7.0, 7.4 and 8.0 and incubated in mTALP solution of pH 7.4 for 9min, sperm acrosome reaction rate was 74.8, 71.8 and 93.4%. pH 8.0 showed signifciantly(p<0.01) higher sperm acrosome reaction rate than pH 7.0 and 7.4. The results suggest that stimulation of sperm with high pH induces sperm crosome reaction.

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The Change of H Reflex by Galvanic Vestibular Stimulation (평류전정자극에 의한 H 반사의 변화)

  • Hwang, Tae-Yeun;Kim, Tae-Youl;Park, Jang-Sung
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.2 no.3
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    • pp.65-73
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    • 2004
  • In experimental method, this study was that galvanic vestibular stimulation in vestibular system influenced the excitability of spinal neuron through. H-reflex was measured by galvanic vestibular stimulation of binaural(right-negative pole and left-positive pole) at left head turning and prone position in sixteen normal subjects in their twenties age were selected. The summary of the comparison results were obtained below. 1. In the change of H reflex according to galvanic vestibular stimulation(GVS), Hmax amplitude(p<.05) increased significantly after stimulation. 2. In the change of H reflex according to galvanic vestibular stimulation(GVS), Hmax/Mmax ratio(p<.05) increased significantly after stimulation. In the conclusion, galvanic vestibular stimulation influenced the excitability of vestibulospinal tract and spinal neuron.

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The Change of H Reflex by Neuromuscular Electrical Stimulation (신경근전기자극에 의한 H 반사의 변화)

  • Lee, Jeong-Woo;Kim, Tae-Youl
    • Journal of Korean Physical Therapy Science
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    • v.10 no.1
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    • pp.65-73
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    • 2003
  • The purpose of this study was to determine whether neuromuscular electrical stimulation(NMES), applied over the antagonist or the agonist, would alter the H reflex. Attention was focused on the roles of stimulus location. We used normal eight subjects without neuromuscular disease which were divided into 3 groups; the subjects were diveded into group of antagonist, agonist, antagonist-agonist. All groups were meted of eight subjects. Neuromuscular electrical stimulation was administered for 15 minutes. All subjects were subjected to three tests, including a pre-test, post-test and post-20 minute test. The data were analyzed by repeated measures ANOVA and paired t-test. The results were as follows; 1. H latencies were significantly increased in agonist and antagonist-agonist group (p<.01). 2. H/M intervals were significantly increased in agonist and antagonist-agonist group (p<.01). 3. H amplitudes were significantly increased in agonist (p<.001) and antagonist-agonist group (p<.01). 4. H/M ratios were significantly decreased in agonist and antagonist-agonist group (p<.01). In agonist group. H-reflex amplitudes and H/M ratios were more significantly decreased than antagonist group. Future studies will need to determine what influence NMES may have on the excitability of spinal motor neurons in people having UMN syndrome.

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Effect of lonomycin and 6-Dimethylaminopurine on Oocyte Activation and Production of Rabbit Nuclear Transplant Embryos (Ionomycin과 6-Dimethylaminopurine이 토끼의 난자 활성화와 핵이식배 생산효율에 미치는 영향)

  • 하란조;강다원;최창용;윤희준;강태영;최상용;이효종;박충생
    • Journal of Embryo Transfer
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    • v.13 no.1
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    • pp.11-19
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    • 1998
  • This study was to determine the effect of ionomycin and 6-dimethylaminopurine (6-DMAP) and/or elcetrical stimulation on the oocyte activation and production of rabbit nuclear transplant embryos. The oocytes were collected from the oviduct of superovulated rabbits at 14 h post hCG injection and cultured in TCM-199 containing 10% FBS until 19 h post hCG injection. To determine the optimum concentration and exposure time of 6-DMAP, some oocytes were activated with 5 $\mu$M ionomycin for 5 min and then in 2.0 mM 6-DMAP for 0.5 to 3.0 h, or in 1.0 to 3.0 mM 6-DMAP for 2.0 h. Other control oocytes were stimulated electrically(3X, 1.25 kV/cm, 60 $\mu$sec) in 0.3 M mannitol solution supplemented with 100 $\mu$M CaCl$_2$ and MgCl$_2$. The nuclear donor embryos of 8-cell stage were synchronized to G$_1$ phase of 16-cell stage, and the recipient cytoplasms were obtained from removal of the first polar body and a portion of membrane bound cytoplasm of the oocytes collected at 15 h post hCG injection. A separated blastomere was injected into the perivitelline space of the enucleated oocytes. The oocytes injected with nucleus were cultured until 19 h post hCG and then electrofused and activated by electrical stimulation with or without ionomycin and 6-DMAP. These nuclear transplant embryos were cultured in TCM-199 containing 10% FBS in 39˚C, 5% CO2 incubator for 120 h. For the oncytes activated parthenogenetically with electrical stimulation with or with-out ionomycin and the various concentration of exposure time of 6-DMAP, the highest cleavage(92.3%) and development to blastocyst stage(41.0%) were resulted from the oocytes activated by ionomycin and 2.0 mM 6-DMAP for 2.0 h, which were found to be significantly(P<0.05) higher than the cleavage(45.2%) and developement to blastocyst stage(14.3%) from the oocytes activated with electrical stimulation. The significantly(P<0.05) more oocytes(71.4%) developed to 4 cell stage at 24 h post activation by ionomycin and 6-DMAP than those by electrical stimulation(18.9%). For the nuclear transplant embryos, the cleavage rate was similarly high in oocyte activation by electrical stimulation with(79.4%) or without ionomycin and 6-DMAP(70.5%). However, the embryo development to blastocyst stage was significantly(P<0.05) higher in oocyte activation by electrical stimulation with ionomycin and 6-DMAP(44.4%) than by electrical stimulation only(25.0%). The significantly(P<0.05) more nuclear transplant embryos(45.6%) developed to 4 cell stage at 18 h post activation by electrical stimulation with ionomycin and 6-DMAP than those by electrical stimulation only(10.6%). These results indicated that the supplemental oocyte activation by ionomycin and 6-DMAP with electrical stimulation enhanced and accelerated the preimplanted in vitro development of the rabbit nuclear transplant embryos.

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α1-adrenoceptor stimulation increases intracellular pH and Na+ via Na+-H+ exchange in guinea pig papillary muscle (기니픽 유두근에서 α1-adrenoceptor 자극에 의한 세포내 pH와 Na+ 증가는 Na+-H+ 교환기를 경유)

  • Kim, Jin-sang
    • Korean Journal of Veterinary Research
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    • v.35 no.2
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    • pp.229-236
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    • 1995
  • The effect of ${\alpha}_1$-adrenoceptor(${\alpha}_1$-AR) stimulation on intracellular pH($pH_i$), $Na^+$ activity($a_{Na}{^i}$) and contractility were investigated in isolated papillary muscles of euthyroid or hyperthyroid guinea pig with conventional microelectrode, $Na^+$ or $H^+$-selective microelectrodes, and tension transducer. Stimulation of the ${\alpha}_1$-AR by phenylephrine produced a decrease in $a_{Na}{^i}$ in euthyroid preparations. This decrease in $a_{Na}{^i}$ was abolished in presence of PKC activator, phorbol dibutyrate, and increased contrary to decrease. Phenylephrine also increased $a_{Na}{^i}$ in hyperthyroid ones. However, phenylrephtine produced an increase in $pH_i$ in both euthyroid and hyperthyroid ones. These changes were blocked by prazosin, an antagonist of ${\alpha}_1$-AR. These findings suggest that the changes in $a_{Na}{^i}$ and $pH_i$ are mediated by a stimulation of $Na^+-H^+$ exchange via ${\alpha}_1$-AR stimulation. This study focused on the increase in $a_{Na}{^i}$, $pH_i$ and contractility. The increase in $pH_i$ was blocked by amiloride or EIPA, $Na^+-H^+$ exchange inhibitors. Therefore, the increase in $a_{Na}{^i}$ and $pH_i$ mediated by ${\alpha}_1$-AR appeared to be due to an influx of $Na^+$ and a reduction of $H^+$ through $Na^+-H^+$ exchange. This study also revealed that the increase in $pH_i$ and $a_{Na}{^i}$ might be related to the sustained positive inotropic response. The $a_{Na}{^i}$ increase may contribute to the intracellular $Ca^{2+}$ through the $Na^+-Ca^{2+}$ exchange, and the $pH_i$ increase could cause an increase in the $Ca^{2+}$ sensitivity of myofilaments and may augment the ${\alpha}_1$-AR-mediated positive inotropic response.

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INFLUENCE OF DIETARY ENERGY AND POSTMORTEM ELECTRICAL STIMULATION ON MEAT QUALITY AND COLLAGEN CHARACTERISTICS OF LAMB CARCASSES

  • Abouheif, M.A.;Al-Saiady, M.Y.;Kraidees, M.S.;Basemaeil, S.M.;Al-Suwaid, A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.6
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    • pp.577-582
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    • 1995
  • Sixty ram lambs, weighting 23.5 kg, were randomly assigned in a $2{\times}3$ factorial arrangement of two dietary energy (high; 11.7 and low; 9.0 MJ ME/kg DM) and three levels of poultry offal meal supplementation (0, 5 and 10%). Lambs were fed ad libitum for 120-day before slaughter. At slaughter, half the lambs in each dietary treatment group were randomly selected for electrical stimulation of their undressed carcasses. The M. Biceps femoris pH and temperatures were monitored at 1, 3, 5, 8 and 24 h postmortem. At 24 h postmortem, the M. biceps femoris was removed from the fight side of each carcass and steaks were obtained for determination of Warner-Bratzler shear force, collagen content and collagen solubility. The results showed that temperature and pH values during the 24-h postmortem were consistently higher (p < .01) and lover (p < .01), respectively, for M. biceps femoris from lambs fed high energy diets than for those fed on low energy diets. Muscles from high energy fed lambs had lower (p < .01) shear force values and higher (p < .01) percent soluble collagen than for low energy fed lambs; total collagen content was not significantly influenced by dietary energy level. Increased the level of poultry offal meal supplementation in the diet to 10% was associated with concomitant increases (p < .01) in muscle tenderness and percent soluble collagen. Electrical stimulation (ES) of carcasses resulted in a lower shear force values for the M. biceps femoris than in non-stimulated carcasses (Non-ES); total collagen content and percent soluble collagen were not significantly affected by ES treatment.

Consecutive versus concomitant follicle-stimulating hormone and highly purified human menopausal gonadotropin: A milder response but better quality

  • Maghraby, Hassan Ali;Agameya, Abdel Fattah Mohamed;Swelam, Manal Shafik;El Dabah, Nermeen Ahmed;Ahmed, Ola Youssef
    • Clinical and Experimental Reproductive Medicine
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    • v.49 no.2
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    • pp.135-141
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    • 2022
  • Objective: This study investigated the impact of two stimulation protocols using highly purified human menopausal gonadotropin (HP-hMG) on the endocrine profile, follicular fluid soluble Fas levels, and outcomes of intracytoplasmic sperm injection (ICSI) cycles. Methods: This prospective clinical trial included 100 normal-responder women undergoing ovarian stimulation for ICSI; 55 patients received concomitant follicle-stimulating hormone (FSH) plus HP-hMG from the start of stimulation, while 45 patients received FSH followed by HP-hMG during mid/late follicular stimulation. The primary outcome was the number of top-quality embryos. The secondary outcomes were the number and percentage of metaphase II (MII) oocytes and the clinical pregnancy rate. Results: The number of MII oocytes was significantly higher in the concomitant protocol (median, 13.0; interquartile range [IQR], 8.5-18.0 vs. 9.0 [8.0-13.0] in the consecutive protocol; p=0.009); however, the percentage of MII oocytes and the fertilization rate were significantly higher in the consecutive protocol (median, 90.91; IQR, 80.0-100.0 vs. 83.33 [75.0-93.8]; p=0.034 and median, 86.67; IQR, 76.9-100.0 vs. 77.78 [66.7-89.9]; p=0.028, respectively). No significant between-group differences were found in top-quality embryos (p=0.693) or the clinical pregnancy rate (65.9% vs. 61.8% in the consecutive vs. concomitant protocol, respectively). The median follicular fluid soluble Fas antigen level was significantly higher in the concomitant protocol (9,731.0 pg/mL; IQR, 6,004.5-10,807.6 vs. 6,350.2 pg/mL; IQR, 4,382.4-9,418.4; p=0.021). Conclusion: Personalized controlled ovarian stimulation using HP-hMG during the late follicular phase led to a significantly lower response, but did not affect the quality of ICSI.

Interleukin-8 and MCP(Monocyte Chemoattractant Protein)-1 expression by the Human Dental Pulps in cultures stimulated with Substance P (사람치수에서 Interleukin-8과 Monocyte chernoattractant protein-1의 분비에 대한 Substance P의 효과에 관한 연구)

  • Shin, Han-Ju;Park, Sang-Hyuk;Choi, Gi-Woon
    • Restorative Dentistry and Endodontics
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    • v.30 no.3
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    • pp.193-203
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    • 2005
  • The induction of the IL-8 and MCP-1 by the stimulation of Substance P and TNF-${\alpha}$ (IL-8 agonist) and the specificity for SP using Spantide (SP antagonist) in the dental pulp tissues was measured quantitatively. In addition, the secretion of the IL-8 in the human dental pulp tissue 36 hrs after the stimulation of SP was observed after the stimulation of SP qualitatively. According to this study the results were as follows: 1. There was the significant IL-8 induction at 36 h after SP (10$^{-4}$M) stimulation of the pulp tissue comparing with the unstimulated dental pulp tissues (p < 0.05) . IL-8 irnmunostaining was weakly detected along the periphery of the pulp tissue after Mock stimulation and IL-8 immunostaining was detected around the fibroblast in the pulp tissue 36h After SP (10$^{-4}$M) stimulation, 2. The secretion of MCP-1 from the dental pulp tissues comparing with Mock stimulation was induced at 36 hrs after TNF-$\alpha$ (40 ng/ml) stimulation, but no induction with SP(10$^{-4}$M) TNF-${\alpha}$ (40 ng/ml) did not induce the IL-8 secretion from the pulp tissue, weak IL-8 imrnunostaining was detected along the periphery of the pulp tissue 3. Spantide (10$^{-5}$M) inhibited IL-8 induction from the pulp tissues 36 h after SP (10$^{-4}$M) stimulation These results suggest that SP significantly induces IL-8 recruiting neutrophils in localized human dental pulp tissue MCP-1 appears to be less involved in the early establishment of pulpal inflammation in response to irritation such as mechanical insult of dentin. SP may have positive relation with the inflammation of the human dental pulp tissues.

The Change of Spinal Motor Neuron Excitability by Neuromuscular Electrical Stimulation (신경근전기자극에 의한 척수운동신경원의 흥분성 변화)

  • Lee, Jeong-Woo;Kim, Tae-Youl;Lee, In-Hak;Lee, Joon-Hee
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.1 no.1
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    • pp.1-15
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    • 2003
  • The purpose of this study was to determine the effect of neuromuscular electrical stimulation(NMES) on the alteration of spinal motor neuron excitability. In this article, I would like to experiment on a standard capacity of clinical electrophysiology, a difference in applying methods and a clinical efficiency of NMES by Nerve conduction velocity. We used normal eight subjects without neuromuscular disease and all subjects participated 3 session, which at least 1 week between session. Participants classified according to each group in Antagonist, Agonist, Antagonist-Agonist by the NMES. The test was measured continuously pre test, post-test, post 20 minute test by EMG including H reflex, F wave, motor nerve conduction velocity(MNCV). The following results were obtained; 1. H-reflex latencies and H/M intervals were significantly increased in agonist and antagonist-agonist group(p<.01). 2. H-reflex amplitudes and H/M ratios were significantly decreased in agonist and antagonist-agonist group(p<.01). In agonist group, H-reflex amplitudes and H/M ratios were more significantly decreased than antagonist group. 3. F-wave latencies were significantly increased in agonist and antagonist-agonist group(p<.01). F/M intervals were significantly increased in antagonist-agonist group(p<.01). F wave conduction velocities were significantly increased in agonist and antagonist-agonist group(p<.01) but F/M ratios were not significant. 4. MNCV were significantly decreased in agonist(p<.01). These results lead us to the conclusion that agonist and Antagonist-agonist was significantly decreased excitability of spinal motor neuron. Conversely, Antagonist does not decreased. Therefore, A further direction of this study will be to provide more evidence that NMES have an effect on excitability of spinal motor neurons in UMN syndrome.

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