• 제목/요약/키워드: Free release

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Statistical patterns of lipase activities on the release of short-chain fatty acids in Cheddar cheese slurries

  • Kwak, Hae-Soo
    • Journal of Dairy Science and Biotechnology
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    • v.7 no.1
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    • pp.6-19
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    • 1989
  • Twenty-five commercial food grade and alalytical grade lipases were used to study the patterns of release of short-chain free fatty acids (FFA) from milk fat in cheese slurries. Principal component Analysis showed that there were four distinctive groups by the FFA ratios and five groups by the FFA concentrations. However, Average Linkage Cluster Analysis showed that the patterns of FFA released were dependent upon distance defined between groups of lipases. All the lipases tested with both statistical analysis had distinctive specificities in hydrolyzing short-chain FFA from milk fat. Lipases from ruminant-animal origins produced an extremely high ratio (>40%) of butyric acid and a low ratio (<26%) of capric acid to total short chain FFA. Lipases from porcinepancreas and some microbial origins showed balanced production in both bytyric and capric acid. However, most lipases from microbial origins released a high ratio of capric acid but similar ratios to other origin enzymes for short-chain free fatty acids. Ruminant-animal origin lipases produced short-chain FFA much higher in concentration than other lipases. Lipases from porcine pancreas as well as microbial origins showed different concentrations of the fatty acids. Ratios of short-chain FFA in each sample were not significantly changed during incubation periods (4 wk), whereas concentrations of the FFA increased considerably.

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Inhibitory Effect of $Mg^{2+}$ on the Release of $Ca^{2+}$ from Ryanodine Receptor of the Sarcoplasmic Reticulum in the Skeletal Muscle (골격근 망상체 $Ca^{2+}$유리 Channel[Raynodine receptor]의 $Mg^{2+}$에 의한 유리 억제)

  • 이철주
    • Journal of Chest Surgery
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    • v.25 no.4
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    • pp.347-355
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    • 1992
  • The precise mechanism of the Excitation-Contraction Coupling is still uncertain. But the concept that Ca2+ induced Ca2+ release [CICR] from the Ryanodine receptor in the sarcoplasmic reticulum [foot structure] may play a major role in E-C coupling has been widely accepted since 1970`s. It is believed that increased cytosolic Ca2+ followed by CICR is main contributor for E-C coupling of striated muscle. Resulting phenomena of ischemic /post-reperfusion myocyte is increased cytosolic Ca2+, even to the absence of Ca2+ in reperfusate. So intracellular inhibitor to CICR might prevent the ischemic and reperfusion damage of myocardial cells. The relatively purified foot protein, especially heavy sarcoplasmic reticulum rich, of the skeletal muscle was incorporated into the black lipid bilayer [Phosphatidyl ethanolamine: Phosphatidyl serine=l: 1]. Under the steady state of membrane potential [+20 mV], ionic current through Ryanodine receptor was measured with Cs+ as charge carrier. In the cis chamber [Cytoplasmic side], Mg2+ strongly inhibited CICR of Ryanodine receptor[Kd=6.2 nM]. In conclusion, naturally existing intracellular free Mg2+ can inhibit CICR from intracellular Ca2+ reservior [heavy SR]. So post-ischemic or post-reperfusing myocardium could be preserved using additional free Mg2+ in cardioplegic solution or reperfusate, otherwise the optimal concentration is undetermined.

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Options Manageing for Radioactive Metallic Waste From the Decommissioning of Kori Unit 1 (고리1호기 해체시 발생할 방사성금속폐기물 관리 옵션 연구)

  • Kessel, David S.;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.2
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    • pp.181-189
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    • 2017
  • The purpose of this paper is to evaluate several leading options for the management of radioactive metallic waste against a set of general criteria including safety, cost effectiveness, radiological dose to workers and volume reduction. Several options for managing metallic waste generated from decommissioning are evaluated in this paper. These options include free release, controlled reuse, and direct disposal of radioactive metallic waste. Each of these options may involve treatment of the metal waste for volume reduction by physical cutting or melting. A multi-criteria decision analysis was performed using the Analytic Hierarchy Process (AHP) to rank the options. Melting radioactive metallic waste to produce metal ingots with controlled reuse or free release is found to be the most effective option.

Preparation and Characteristics of Surface-Modified Albumin Microspheres with Methotrexate (메토트렉세이트가 표면수식된 알부민 미립구의 제조 및 특성)

  • Hwang, Sung-Joo;Jo, Hang-Bum;Rhee, Gye-Ju;Kim, Chong-Kook
    • Journal of Pharmaceutical Investigation
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    • v.25 no.2
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    • pp.101-108
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    • 1995
  • The surface of albumin microspheres could be modified with methotrexate (MTX) by using 1,3-dicyclohexylcarbodiimide (DCC). Surface-modified albumin microspheres entrapping no MTX (SAMS), free MTX (SAMSF) and MTX-bovine serum albumin (BSA) conjugates (SAMSC) were prepared. respectively, and their release characteristics were investigated in the presence of trypsin using a dissolution tester. The mean diameters of all the microspheres were $5{\sim}8\;{\mu}m$, and their shapes was small and uniform. MTX bound tn their surfaces was released slower than the entrapped free MTX, and laster than the entrapped MTX-BSA conjugates. Also, surface-modified MTX was scarcely released in the absence of a proteolytic enzyme. Therefore, the surface-modified MTX may be released rapidly from SAMSC at the target site, and thereafter MTX may be released slowly from the encapsulated MTX-BSA conjugates in SAMSC for a long period.

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Role of Plasma Osmolality in AVP and Aldosterone Release in Korean Young Men (혈장 삼투질 농도 변동에 따른 항이뇨 호르몬과 Aldosterone 분비조절 : 한국청년)

  • Lee, Won-Jung;Choo, Young-Eun;Koo, Ja-Hoon
    • The Korean Journal of Physiology
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    • v.21 no.2
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    • pp.297-304
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    • 1987
  • A study was carried out to find out the relationship between arginine vasopressin (AVP) release and plasma osmolality in 15 young men (age: 21.4 yr). After an overnight fasting, wale. (20 ml/kg) was imbibed, and venous blood and urine samples were collected every 30 min for 90 min. then 5% saline was infused (0.06 ml/min/kg) for 120 min. AVP was extracted on Sep-Pak column and measured by radioimmunoassay. Under basal condition, plasma osmolality (pOsm), AVP (pAVP) and aldosterone (pAldo) levels were 286.5 mOsm/kg, 1.1 pg/ml, and 140 pg/ml, respectively. pAVP became undetectable during maximum water diuresis, and increased in response to hypertonic saline infusion. pAVP level began to increase when pOsm was above 280 mOsm/kg. Changes in urinary AVP excretion (uAVP) was parallel to pAVP levels. The fall in pAVP was followed by a decrease in uAVP, uOsm and an increase in free water clearance, while the later rise in pAVP was followed by an increase in uAVP, uOsm and a decrease in free water clearance. When pooling all data together, relationships between pAVP and pOsm, and uAVP and uOsm were best expressed by an exponential relationship (r=0.78, 0.86, respectively). pAldo level decreased to 71 pg/ml after water ingestion, and decreased further to 30 pg/ml 2 hr after 5% saline infusion. Even at the same pNa, pAldo level during dehydration state was significantly higher than during hydration state. Negative exponential relation (r=-0.59) was observed between pAldo and pNa. Response to change in body fluid volume was greater in aldosterone than in AVP release.

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Development of Polymeric Nanopaclitaxel and Comparison with Free Paclitaxel for Effects on Cell Proliferation of MCF-7 and B16F0 Carcinoma Cells

  • Yadav, Deepak;Anwar, Mohammad Faiyaz;Garg, Veena;Kardam, Hemant;Beg, Mohd Nadeem;Suri, Suruchi;Gaur, Sikha;Asif, Mohd
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2335-2340
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    • 2014
  • Paclitaxel is hydrophobic in nature and is recognized as a highly toxic anticancer drug, showing adverse effects in normal body sites. In this study, we developed a polymeric nano drug carrier for safe delivery of the paclitaxel to the cancer that releases the drug in a sustained manner and reduces side effects. N-isopropylacrylamide/vinyl pyrrolidone (NIPAAm/VP) nanoparticles were synthesized by radical polymerization. Physicochemical characterization of the polymeric nanoparticles was conducted using dynamic light scattering, transmission electron microscopy, scanning electron microscopy and nuclear magnetic resonance, which confirmedpolymerization of formulated nanoparticles. Drug release was assessed using a spectrophotometer and cell viability assays were carried out on the MCF-7 breast cancer and B16F0 skin cancer cell lines. NIPAAm/VP nanoparticles demonstrated a size distribution in the 65-108 nm range and surface charge measured -15.4 mV. SEM showed the nanoparticles to be spherical in shape with a slow drug release of ~70% in PBS at $38^{\circ}C$ over 96 h. Drug loaded nanoparticles were associated with increased viability of MCF-7 and B16F0 cells in comparison to free paclitaxel. Nano loaded paclitaxel shows high therapeutic efficiency by sustained release action for the longer period of time, i increasing its efficacy and biocompatibility for human cancer therapy. Therefore, paclitaxel loaded (NIPAAm/VP) nanoparticles may provide opportunities to expand delivery of the drug for clinical selection.

Prevention of Ischemic Damage in Working Rat Hearts by Calcium Channel Blocker and Calmodulin Inhibitors (흰쥐심장의 허혈손상에 대한 Calcium 통로봉쇄제와 Calmodulin 억제제의 예방효과에 대한 연구)

  • 성시찬
    • Journal of Chest Surgery
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    • v.22 no.6
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    • pp.901-913
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    • 1989
  • This study was investigated under the postulation that activation of intracellular calcium- calmodulin complex during ischemia-reperfusion leads to myocardial injury. The protective effects of calcium channel blocker, diltiazem and calmodulin inhibitors, trifluoperazine, flunarizine and calmidazolium from ischemic injury in rat hearts were observed by using Langendorff apparatus when the antagonists were infused for 3 min in the beginning of ischemia. Thereby, an increase in resting tension developed during 30-min ischemia was analyzed with regard to [1] the degree of cardiac functional recovery following 60-min reperfusion, [2] changes in biochemical variables evoked during 30-min ischemia. The results obtained were as follows: l. In the ischemic group, the resting tension was increased by 4.1*0.2 g at 30-min ischemia. However, the increase in resting tension was markedly reduced not only by pretreatment with diltiazem [3.3 p M] but also with calmodulin inhibitors, trifluoperazine [3.3 p M], flunarizine [0.5 p M] and calmidazolium [0.5 p M], respectively. 2. Recovery of myocardial contractility, +dF /dt and coronary flow were much reduced when evoked by reperfusion in the ischemic group. These variables were significantly improved either by pretreatment with diltiazem or with calmodulin inhibitors. 3. The resting tension increment evoked during ischemia was significantly inversely correlated with the degree of cardiac function recovered during reperfusion. 4. Following 30-min ischemia, the production of malondialdehyde and release of lysosomal enzyme were much increased in association with a decrease in creatine kinase activity. 5. The increases in malondialdehyde production and release of free lysosomal enzyme were suppressed by pretreatment with calmodulin inhibitors as well as diltiazem. Likewise, the decrease of creatine kinase activities was prevented by these calcium antagonists. With these results, it is indicated that a increase in resting tension observed during ischemia has an inverse relationship to the cardiac function recovered following reperfusion, and further, the later may be significantly dependent on the degree of biochemical alterations occurred during ischemia such as decrease in creatine kinase activity, increased production of malondialdehyde and increased release of free lysosomal enzyme. Thus it is concluded that calmodulin plays a pivotal role in the process of ischemic injury.

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Effects of Lactobacillus helveticus Fermentation on the Ca2+ Release and Antioxidative Properties of Sheep Bone Hydrolysate

  • Han, Keguang;Cao, Jing;Wang, Jinghui;Chen, Jing;Yuan, Kai;Pang, Fengping;Gu, Shaopeng;Huo, Nairui
    • Food Science of Animal Resources
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    • v.38 no.6
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    • pp.1144-1154
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    • 2018
  • Both the calcium and collagen in bone powder are hard to be absorbed by the body. Although enzymatic hydrolysis by protease increased the bio-availability of bone powder, it was a meaningful try to further increase $Ca^{2+}$ release, oligopeptide formation and antioxidant activity of the sheep bone hydrolysate (SBH) by lactic acid bacteria (LAB) fermentation. Lactobacillus helveticus was selected as the starter for its highest protease-producing ability among 5 tested LAB strains. The content of liberated $Ca^{2+}$ was measured as the responsive value in the response surface methodology (RSM) for optimizing the fermenting parameters. When SBH (adjusted to pH 6.1) supplemented with 1.0% glucose was inoculated 3.0% L. helveticus and incubated for 29.4 h at $36^{\circ}C$, $Ca^{2+}$ content in the fermented SBH significantly increased (p<0.01), and so did the degree of hydrolysis and the obtaining rate of oligopeptide. The viable counts of L. helveticus reached to $1.1{\times}10^{10}CFU/mL$. Results of Pearson correlation analysis demonstrated that LAB viable counts, $Ca^{2+}$ levels, obtaining rates of oligopeptide and the yield of polypeptide were positively correlated with each other (p<0.01). The abilities of SBH to scavenge the free radicals of DPPH, OH and ABTS were also markedly enhanced after fermentation. In conclusion, L. helveticus fermentation can further boost the release of free $Ca^{2+}$ and oligopeptide, enhance the antioxidant ability of SBH. The L. helveticus fermented SBH can be developed as a novel functional dietary supplement product.

Activation Mechanism of Arachidonic Acid in Human Neutrophil Function (사람 중성호성 백혈구의 기능에 있어서 Arachidonic Acid의 활성화 기전)

  • Sim, Jae-Kun;Lee, Chung-Soo;Shin, Yong-Kyoo;Lee, Kwang-Soo
    • The Korean Journal of Pharmacology
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    • v.28 no.1
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    • pp.91-102
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    • 1992
  • In $Ca^{++}$ containing media, arachidonic acid markedly stimulated superoxide and $H_2O_2$ generation and activated NADPH oxidase. In $Ca^{++}$ free media, stimulatory action of arachidonic acid on NADPH oxidase was not detected. Arachidonic acid-stimulated respiratory burst was inhibited by EGTA, TMB-8, verapamil, diltiazem, nifedipine, dibucaine, lidocaine, CCCP, 2,4-dinitrophenol, sodium arsenate, chlorpromazine, theophylline, $HgCl_2$, PCMB and PCMBSA but not affected by tetrodotoxin, tetraethylammonium chloride and procaine. EGTA almost completely inhibited release of ${\beta}-glucuronidase$ by arachidonic acid and verapamil, CCCP and theophylline slightly inhibited it, whereas dibucaine did not show any significant effect. Arachidonic acid induced $Ca^{++}$ release from intact neutrophils and it was decreased by TMB-8. Arachidonic acid-induced elevation of intracellular free $Ca^{++}$ level was inhibited by EGTA and CCCP and slightly inhibited by TMB-8. Amount of intracellular free $Ca^{++}$ increased by either arachidonic acid plus verapamil or arachidonic acid plus dibucaine was greater than that by arachidonic acid alone. These results suggest that various changes of biochemical events may be implicated in the functional expression in neutrophils activated by arachidonic acid. Arachidonic acid appears to elevate cytosolic free $Ca^{++}$ level by stimulating $Ca^{++}$ release from intracellular $Ca^{++}$ storage sites. During activation of neutrophils, $Ca^{++}$ influx and efflux may be accomplished, simultaneously.

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Effect of Diphtheria Toxin on the Phospholipase D activity and Free Fatty Acid Release in HepG2 Cells (HepG2 세포의 포스포리파제 D 활성과 자유 지방산 방출에 대한 디프테리아 독소의 영향)

  • Koh, Eun-Hie
    • Journal of the Korean Chemical Society
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    • v.59 no.1
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    • pp.22-30
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    • 2015
  • The effect of diphtheria toxin on cell membrane lipids was studied by examining the phospholipase D (PLD) activity and free fatty acids (FFA) release in HepG2 cells. The diphtheria toxin effects on lipid alteration show apparently maximal at pH 5.1, stimulating PLD activity nearly 3.5 fold and enhancing FFA release approximately 5 fold over the control. These results indicate that the membrane is perturbed and its lipid component is rearranged during the diphtheria toxin translocation. Digitonin, a random membrane perturbing detergent, exhibit about four-fold higher perturbation effect over the diphtheria toxin at neutral pH. This observation suggests that the membrane perturbation induced by diphtheria toxin appears to be rather selective. To investigate the cause of the membrane perturbation, Cibacron blue, an inhibitor of membrane pore formation, and hemagglutinin, an influenza virus with fusion peptide, were tested for their effects on diphtheria toxin action. Cibacron blue decreased the diphtheria toxin effect by almost 50%, but the lipid alteration induced by hemagglutinin was similar to the diphtheria toxin effect. These observations imply that the membrane perturbation induced by diphtheria toxin may be caused by a combination of pore formation and insertion of hydrophobic peptide of toxin to the membrane as well. Additionally, we found that the diphtheria toxin increased the HepG2 cells permeability but the cells viability was maintained at high level at the same time. DNA fragmentation which is related to apoptosis was not induced by the toxin. Under these conditions, we could demonstrate that the lipid alteration of HepG2 cells was brought about by diphtheria toxin at acidic pH.