• Archives of Pharmacal Research
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• 제12권2호
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• pp.88-93
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• 1989

In order to obtain some informations about the effect of molecular weight on the release rate of drug from drug carrier, two types of poly-L-glutamic acid (PLGA)-cytarabine (ara-C) conjugates, PLGA-ara-C:I and PLGA-ara-C:II, were synthesized using two types of PLGA having different average molecular weight, 43,000 and 77,800, respectively. The PLGA-ara-C conjugates were synthesized by mixed anhydride method and found to be covalently linked. Both types of conjugates charged negatively at biological pH. The pH-dependent release rate of ara-C was observed in both cases, and the release rate was accelerated in basic, acidic conditions (the k values were 0.015 $day^{-1}$ at pH 7.0, 0.024 $day^{-1}$ at pH 5.0, and 0.059 $day^{-1}$ at pH 9.0 in the case of PLGA-ara-C:I) and in the presence of pretense. The time required for the release of 16.5% of ara-C from PLGA-ara-C:I were 8 hr and 144 hr in the presence and absence of protease, respectively. Although both types of conjugates showed similar drug substitution ratio, they showed different release rates. Between the two types of conjugates, PLGA-ara-C:II showed the faster release rate (0.030 vs 0.042 $day^{-1}$ in pH 7.4 phosphate buffer solution at $37^{\circ}C$) and the smaller activation energy for the release of drug (12.5 vs 7.7 Kcal/mol) than PLGA-ara-C:I. The characteristic effect of molecular weight on the release rates of PLGA-ara-C conjugates suggests that the drug release rate might be effectively controlled over a prolonged period of time by the combined use of the different types of PLGA-ara-C conjugates having different molecular weights.

• Clinical and Experimental Pediatrics
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• 제46권12호
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• pp.1186-1193
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• 2003

목 적 : 염색체 취약부위는 세포를 특정의 화학물질에 노출시키거나 특수한 배양조건에서 배양 할 때 쉽게 파열되는 염색체상의 특정구역이다. 취약부위는 유전성질환 및 악성종양과 관련이 있으며, 현재에는 분자생물학적 실험기법의 개발로 분자수준에서 이해가 되고 있다. 새로운 취약부위 및 취약부위의 발현을 높이거나 쉽게 관찰할 수 있는 실험실적 조건을 알아보기 위하여 항암제로 사용되는 Ara-C를 이용하여 염색체파열을 조사하여 보았다. 한편 염색체 취약부위가 종양형성과 관련이 있다는 사실에 기초하여 Ara-C에 의해 발열되는 취약부위와 암유전자가 위치하는 부위 및 종양에서 일정하게 염색체변이가 관찰되는 특정의 염색체 부위와의 상관관계도 알아보고자 하였다. 방 법 : 정상 성인 남녀 각각 3명의 말초혈액 내 T-림프구를 세포배양 후 Ara-C를 첨가하고 다시 caffeine을 처리한 뒤 종전에 시행했던 방법과 동일하게 검체 처리하여 염색체파열 부위를 관찰하였다. 염색체 취약부위는 염색체상의 일정부위에서 100개의 염색체파열 당 2회 이상의 염색체파열이 6명 중 4명 이상에서 관찰되는 경우로 정의하였다. 결 과 : 1) T-림프구를 엽산이 부족한 MEN-FA 배지에서 배양 시 Ara-C는 100개의 분열세포 당 252.1개의 염색체파열을 유도하였으며, Ara-C를 처리하지 않은 대조군에서 25.2개가 관찰되어 Ara-C를 처리한 경우에 염색체파열이 의미 있게 많았다(P<0.05). 2) Ara-C에 의한 염색체파열은 엽산이 부족한 MEM-FA 배지에서 엽산이 충분한 RPMI 1640 배지에서 보다 많이 되었다(P<0.05). 한편, 2.0 mM 농도의 caffeine은 엽산만 부족한 배양 배지에서는 염색체파열을 상승시키지 못했으나, Ara-C와 병행사용 시 상승시켰다. 3) Ara-C에 의해 가장 많이 파열된 부위는 3p14.2.이었으며, 발현된 취약부위는 20부위였다. 4) 발현된 취약부위 중 7 부위는 JUN, SKI, REL, N-MYC, FHIT, MET, ETS-1, FOS의 암유전자가 위치하는 부위와 일치하였으며, 15부위는 급성림프구성백혈병, 급성골수성백혈병, 만성림프구성백혈병, 골수이형성성증, 악성흑색종, 신경모세포종, 소세포성폐암, 난소암, 유전성 신장암, 혼합성 지방육종시 염색체상에 이상이 있는 부위와 일치하였다. 결 론 : S기 특이성 항암제인 Ara-C는 정상성인의 T-림프구를 엽산이 부족한 MEM-FA배지에서 배양시 염색체 파열을 대조군에 비해 의미 있게 유도하였다. 한편으로 Ara-C 특이성 염색체 취약부위는 암유전자가 위치하는 부위 및 특정 종양에서 관찰되는 특이한 염색체변이가 있는 부위와 상당 예에서 일치하여 아직 알려지지 않은 암유전자를 찾거나 분석하는데 기초적인 자료를 제공할 뿐 아니라 염색체변화와 종양형성과정의 상관관계를 이해하는데 도움이 될 것으로 사료된다.

• 대한물리의학회지
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• 제9권2호
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• pp.141-149
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• 2014

PURPOSE: This study uses X-rays investigate how university students' smart phone use affects the cervical vertebral angle. METHODS: Ninety-two randomly selected students agreed to participate in this study. The participants' number of hours of smart phone use was gathered using a questionnaire. An X-ray of the participants' cervical vertebrae was taken, and the cervical vertebral angle was measured using the Cobb and the absolute rotation angle (ARA) method. Also, the relation between pain and hours of smart phone use was identified using a visual analog scale (VAS). Using SPSS ver18, the relationships among the cervical vertebral angle and the items in the questionnaire were identified and a frequency analysis, an independent t-test, and the analysis of variance (ANOVA) were calculated. RESULTS: The study showed that an increase in the number hours of smart phone per day led to cervical lordosis(p<0.05). The relationships between points of smart phone addiction and cervical vertebral angle have a negative correlation (p<0.05). Therefore, there are the higher smart phone addiction points, the decrease the cervical vertebral angle. CONCLUSION: The results of the study showed that increase in smart phone use lead to cervical lordosis, and smart phone addiction scores resulted in decreased in the cervical vertebral angle.

• Asian Pacific Journal of Cancer Prevention
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• 제17권12호
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• pp.5251-5256
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• 2016

Background: Diagnostic karyotyping analysis is routinely used in acute myeloid leukemia (AML) clinics. Categorization of patients into risk stratified groups (favorable, intermediate and adverse) according to cytogenetic findings can serve as a valuable independent prognostic factor. Method and Material: A retrospective descriptive study was conducted based on the patient records of newly diagnosed non-M3 AML young adult cases undergoing standard 3+7 i.e, Daunorubicin and Ara-C (DA) as remission induction chemotherapy. Diagnostic cytogenetic analysis reports were analyzed to classify the patients into risk stratified groups according to South West Oncology Group criteria and prognostic significance was measured with reference to achievement of haematological remission after 1st induction chemotherapy. Results:A normal karyotype was commonly expressed, found in 47.2% of patients, while 65% (n=39) appeared to have intermediate risk cytogenetics, and 13.3% (n=8) adverse or unclassified findings. Favourable cytogenetics was least frequent in the patient cohort, accounting for only 8.3 % (n=5).The impact of cytogenetic risk groups on achievement of haematological remission was evaluated by applying Pearson Chi-square, and was found to be non-significant (df=12, p=0.256) but when the outcomes of favourable risk groups with intermediate, adverse and unclassified findings compared, results were highly significant (df=6, p=0.000) for each comparison. In patients of the favourable cytogenetic risk group, HR?? was reported in 40% (n=2/5), as compared to 62.2% (n=23/37) in the intermediate cytogenetic risk group, 57.1% (n=4/7) in the adverse cytogenetic risk group and 28.6% (n=2/7) in hte unclassified cytogenetic risk group. Conclusion: Cytogenetic risk stratification for AML cases following criteria provided by international guidelines did not produce conclusive results in our Pakistani patients. However, we cannot preclude an importance as the literature clearly supports the use of pretreatment karyotyping analysis as a significant predictive marker for clinical outcomes. The apparent differences between Pakistani and Western studies indicate an urgent need to develop risk stratification guidelines according to the specific cytogenetic makeup of South Asian populations.