• 한국미생물·생명공학회지
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• 제22권3호
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• pp.290-295
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• 1994

Micelle, liposome and polyethylene glycol(PEG) were employed to reduce the cell mem- brane toxicity of Amphotericin B(Amp. B). Cholesterol-sulfate which can form a mixed micelle with Amp. B molecules was found very effective for the reduction of Amp. B toxicity. 0.01% of cholesterol-sulfate could reduce the toxicity of 5X 10$^{-6}$ M Amp. B by 90%. The required concent- ration of cholesterol-sulfate for the toxicity reduction was proportionally increased with increasing Amp. B concentration. PEG was also effective on the reduction of Amp. B toxicity. 2% PEG was required for the reduction of toxicity by 50%, regardless of Amp. B concentration. The liposome system showed an effective reduction of Amp. B toxicity on RBC, maintaining the antibiotic effect on Candida albicans as free drugs. This seems to be due to the fact that liposome bilayer plays a role of buffer system between ergosterol of fungi cell membrane and cholesterol of red blood cell membrane, which leads the redistribution of Amp. B between them, as the result, the reduction of drug toxicity on cell membrane.

• 방사성폐기물학회지
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• 제11권4호
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• pp.259-269
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• 2013

무기 이온교환제인 ammonium molybdophosphate(AMP)와 자성을 가지는 산화철(iron oxides, IO)을 혼합하고, 유기 지지체인 polyacrilonitrile(PAN)을 결합하여 AMP/IO-PAN 복합체를 합성하였으며 액체 방사성폐액 내 방사성 핵종의 처리 적용성을 평가하였다. 합성된 AMP/IO-PAN 복합체의 물성을 X-선 회절분석(XRD), 퓨리에 변환 적외선 분광분석(FT-IR), 주사전자현미경(SEM), 입도분석기(PSA), 비표면적 및 공극 분석, 자성 측정(MPMS) 분석을 통해 파악하고, 코발트, 스트론튬, 세슘에 대한 흡착 성능을 평가하였다. 10wt%의 산화철이 함유된 AMP/IO-PAN 복합체의 자성 측정 결과, 2.038 emu/g으로 나타났다. 10wt%의 산화철이 함유된 AMP/IO-PAN 복합체의 Langmuir 모델로 예측한 코발트, 스트론튬, 세슘에 대한 최대흡착량($Q^0$)은 각 0.097 mmol/g, 0.087 mmol/g, 0.655 mmol/g으로 나타났다. 0, 10, 20, 30wt%의 산화철이 함유된 AMP/IO-PAN 복합체의 Langmuir 모델로 예측한 세슘에 대한 최대흡착량($Q^0$)은 각각 0.702 mmol/g, 0.655 mmol/g, 0.602 mmol/g, 0.559 mmol/g으로 나타났으며, 첨가된 산화철의 양이 증가할수록 AMP/IO-PAN 복합체의 세슘 흡착량이 감소하였다.

• Journal of Pharmaceutical Investigation
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• 제24권1호
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• pp.41-48
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• 1994

A new local drug delivery device to treat otitis media (OM) has been developed. This device consists of a biodegradable poly(L-lactic acid) (PLLA) film containing antibiotic (ampicillin, AMP), which can be placed into the middle ear cavity and release the therapeutic concentration of AMP for prolonged period. Biodegradable films containing AMP (10 w/w%) were prepared by solution casting method using a suspension of the drug in a $PLLA/CH_{2}Cl_{2}$ solution (molecular weight of PLLA, 100,000 (100 K) and 300,000 (300 K), respectively). PLLA-AMP films were characterized by FTIR, DSC, and SEM. In vitro release of AMP from AMP-PLLA films were examined. The release pattern of AMP from AMP-PLLA films remained consistent from 1 day to 14 days, and the release rates of AMP from AMP-100K-PLLA film and AMP-300K-PLLA film were $0.7384\;{\mu}g/ml/day$, $0.4107\;{\mu}g/ml/day$, respectively.

• 대한치과교정학회지
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• 제16권1호
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• pp.51-70
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• 1986

Parathyroid hormone (PTH) is known to exert its effects on bone cells through the mediation of adenosine 3', 5'-monophosphate (cAMP). Orthodontic forces have also been shown to alter the cAMP content of paradental cells, particularly the alveolar bone osteoblasts. The objective of this experiment was to determine whether a combined orthodontic treatment-PTH administration regimen would have an additive effect on cAMP content in paradental cells in sites of periodontal ligament (PDL) tension. Seven groups of 4 one year old female cats each were treated for 1,3,6,12,24 h, 7 and 14 d by tipping one maxillary canine. PTH was administered twice daily, 30u/kg. Maxillary horizontal sections were stained immunohistochemically for cAMP and the degree of cellular staining intensity was determined microphotometrically as per cent light transmittance at 600nm. Alveolar bone osteoblasts, progenitor cells, PDL fibroblasts and cementoblasts in tenion sites were measured and the data were analyzed statistically by a mixed model analysis of variance. PTH administration increased the cAMP staining of nonorthodontically treated paradental cells in comparison to cells untreated by force or hormone. Cells in PDL tension sites of PTH-treated cats demonstrated significantly darker cAMP staining than cells in non-orthodontically-treated sites. Osteoblasts demonstrated the greatest response in terms of cAMP elevation, while in PDL fibroblasts orthodontic force did not increase cAMP levels above those measured in non-stretched hormonally-treated cells. These results demonstrate that PTH increases cAMP levels in paradental cells, particullarly in osteoblasts, and that the effects of PTH and orthodontic forces on paradental target cells may approach additivity.

• 대한수의학회지
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• 제39권1호
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• pp.62-69
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• 1999

Although it has been reported that hormones or chemicals, which increase in intracellular cAMP, produced $Mg^{2+}$ release from the heart, it is not well characterized whether a specific $Mg^{2+}$ exchanger is involved in cAMP-induced $Mg^{2+}$ efflux in the mammalian hearts. In this work, we studied the relationship between the increase in intracellular cAMP and ion transport system on $Mg^{2+}$ regulation in the perfused rat heart and isolated myocytes. The $Mg^{2+}$ content in the perfusate and supernatant were measured by atomic absorption spectrophotometer. The addition of membrane permeable cAMP analogue to the perfused hearts and myocytes induced a $Mg^{2+}$ efflux in the dose dependent manners. $Mg^{2+}$ efflux was stimulated by cAMP modulators (forskolin, IBMX and Ro20-1724) in the perfused hearts and myocytes. cAMP-induced $Mg^{2+}$ efflux was inhibited by $H_7$, benzamil or imipramine in the perfused hearts and myocytes, but not by EIPA. We confirmed that a significant $Mg^{2+}$ efflux was induced by an increase in intracellular cAMP in the hearts and myocytes. The cAMP-induced increase of $Mg^{2+}$ efflux in the hearts may be involved in ion transport system ($Na^+-Ca^{2+}$ and $Na^+-Mg^{2+}$ exchanger).

• International Journal of Oral Biology
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• 제36권2호
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• pp.83-89
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• 2011

Substantia gelatinosa (SG) neurons receive synaptic inputs from primary afferent $A{\delta}$- and C-fibers, where nociceptive information is integrated and modulated by numerous neurotransmitters or neuromodulators. A number of studies were dedicated to the molecular mechanism underlying the modulation of excitability or synaptic plasticity in SG neurons and revealed that second messengers, such as cAMP and cGMP, play an important role. Recently, cAMP and cGMP were shown to downregulate each other in heart muscle cells. However, involvement of the crosstalk between cAMP and cGMP in neurons is yet to be addressed. Therefore, we investigated whether interaction between cAMP and cGMP modulates synaptic plasticity in SG neurons using slice patchclamp recording from rats. Synaptic activity was measured by excitatory post-synaptic currents (EPSCs) elicited by stimulation onto dorsal root entry zone. Application of 1 mM of 8-bromoadenosine 3,5-cyclic monophosphate (8-Br-cAMP) or 8-bromoguanosine 3,5-cyclic monophosphate (8-Br-cGMP) for 15 minutes increased EPSCs, which were maintained for 30 minutes. However, simultaneous application of 8-BrcAMP and 8-Br-cGMP failed to increase EPSCs, which suggested antagonistic cross-talk between two second messengers. Application of 3-isobutyl-1-methylxanthine (IBMX) that prevents degradation of cAMP and cGMP by blocking phosphodiesterase (PDE) increased EPSCs. Co-application of cAMP/cGMP along with IBMX induced additional increase in EPSCs. These results suggest that second messengers, cAMP and cGMP, might contribute to development of chronic pain through the mutual regulation of the signal transduction.

• KSBB Journal
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• 제9권3호
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• pp.266-271
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• 1994

Amp. B의 세포막 독성을 낮추기 위하여 egg phosphatidylcholine를 사용한 리포좀계를 이용하였다. 리포좀에 포획 된 Amp.B는 Candida albicans에 대해 free drug보다 향상되거나 동일한 항생효과를 가지면서도 동시에 적혈구에 대한 세포막 독성은 현 저히 감소된 것으로 나타났다. 이러한 현상은 Ca$\pi$dida albicans의 ergosterol이나 적혈구의 ch이es­t terol사이에 리포좀이라는 제3의 이중막이 존재할 경우 이들 사이에서 Amp. B가 재분배하게 되어 상대적으로 적혈구에 대한 독성은 줄어드나 리포좀보다는 ergosterol에 대한 친화력이 크므로 항생효과의 면에서는 큰 변화가 없는 것으로 보인다. Candiida의 세포벽과 결합할 수 있는 효소를 리포좀 표면에 삽입하기 위하여 ${\beta}$-glucuronidase를 이용하였으나 약물전달의 상승효과는 크게 나타나지 않았다.

• Journal of Ginseng Research
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• 제21권3호
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• pp.141-146
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• 1997

The role of cAMP in the differentiation process of F9 cells induced by ginsenosides was examined by performing transient transfixion assay with CRE-luciferase reporter plasmid, GR thansactivation assay with GRE-luciferase activity with or without treatment of CAMP and forskolin, an activator of adenylate cyclase, and protein klnase A assay in the presence of ginsenosides. Ginsenosides had no effect on CRE-transactivation activity, whereas retinoic acid induced the activity. When cAMP or forskolin was treated with ginsenosides, GRE-luciferase activity was further augumented by them. In addition, ginsenosides induced protein kinase A activity in the presence of cAMP. These results suggest that ginsenosides activate cAMP-dependent protein kinase A which, in turn, increase GR activity in F9 cells.

• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1527-1535
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• 2009

Polyphosphate (polyP) plays diverse physiological functions in prokaryotes and eukaryotes, but most of their detailed mechanisms are still obscure. Here, we show that deletion of polyphosphate kinase (PPK), the principal enzyme responsible for synthesis of polyP, resulted in augmented expression of cAMP receptor protein (CRP) and rpoS and lowered $H_2O_2$ sensitivity in Salmonella Typhimurium ATCC14028. The binding of cAMP-CRP complex to rpoS promoter and further stimulation of its transcription were proved through electrophoretic mobility shift assay, lacZ fusion, and exogenous cAMP addition, respectively. The rpoS expression increased in cpdA (cAMP phosphodiesterase coding gene) mutant, further suggesting that cAMP-CRP upregulated rpoS expression. These results demonstrate that PPK affects oxidative stress response by modulating crp and rpoS expression in S. Typhimurium.

• 한국동물학회지
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• 제18권1호
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• pp.27-40
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• 1975

dbcAMP와 theophylline이 난자의 성숙을 억제하는 기작과 난자내 glycogen 함량과의 관계를 밝혀보기 위하여 실험한 결과는 다음과 같다. 1. 생쥐 여포난자의 PAS 양성물빌은 glycogen이며 핵의 성숙분열이 진행됨에 따라 glycogen의 함량은 감소한다. 2. dbcAMP나 theophylline에 의해 핵의 성숙이 억제된다 하더라도 난자내의 glycogenolysiss는 촉진된다. 이에 반해 핵분열이 일어나지 않은 난자는 배양이 진행되더라도 glycogen을 그대로 유지하고 있다. 일단 dbcAMP나 theophylline에 의해 성숙이 억제되었던 난자가 성숙과정에 들어가려면 다시 glyconeogenesis가 일어나 세포질내의 glycogen의 양이 회복하며 이때의 glycogen은 핵성숙과 더불어 소모된다. 3. Glycogen의 회복은 배양액내의 glucose 유무에 관계없이 이루어지며 따라서 이는 난자내 glucose 혹은 다른 전구물질에 의해 이루어지리라고 추측된다. 4. 결국 dbcAMP나 theophylline은 난자내 cAMP의 양을 증가시켜 glycogen의 소모를 일으키는 것으로 생각되며, glycogenolysis와 난자의 핵 성숙과정이 별개로 진행되기는 하지만 성숙의 요건은 일정량 이상의 glycogen이 함유되어 있어야 한다는 것을 알게되었다.