• 제목/요약/키워드: Vascular resistance

검색결과 189건 처리시간 0.028초

Descending Aorta Blood Flow Characteristics before the Development of Necrotizing Enterocolitis in Preterm Neonates

  • Kim, Kyung Min;Kim, Hyo Sup;Yoon, Ji Hong;Lee, Eun-Jung;Yum, Sook Kyung;Moon, Cheong-Jun;Youn, Young-Ah;Kwun, Yoo Jin;Lee, Jae Young;Sung, In Kyung
    • Neonatal Medicine
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    • 제25권2호
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    • pp.78-84
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    • 2018
  • Purpose: To investigate the hemodynamic risk factors for necrotizing enterocolitis (NEC), we analyzed the characteristics of descending aorta (DA) blood flow in preterm neonates, who later developed NEC. Methods: This was an observational case-control study on 53 preterm neonates at a tertiary referral center. Clinical and echocardiographic data were collected from 23 preterm neonates with NEC (NEC group), and compared with those of 30 preterm neonates without NEC (control group). Echocardiography was done at a median (interquartile range) of 5 (3-9) days after birth and 2 (1-2.5) days before the diagnosis of NEC. Results: Basic clinical characteristics including gestational age, birth weight, Apgar score, breast feeding status, use of umbilical catheters, and mode of invasive ventilator care were similar between the groups. Compared with the control group, the lowest diastolic velocity of DA was significantly decreased, whereas the diastolic reverse flow and the ratio of diastolic reverse to systolic forward flows were significantly increased in the NEC group. In addition, the resistive index (RI) of DA was significantly increased in the NEC group and showed a positive association with the development of NEC. Multivariate logistic regression analysis showed that increasing RI of DA was an independent risk factor for the development of NEC (P=0.008). Conclusion: Significant changes in DA flow characteristics including decreased diastolic velocity and increased diastolic reverse flow along with increased peripheral vascular resistance were observed before the development of NEC in preterm neonates. These findings may help clinicians stratify in advance neonates at a risk of developing NEC and may help improve outcomes in these neonates.

카드뮴 중독(中毒)에 의한 이곡혈관운동성(耳穀血管運動性)의 변동(變動) (Alteration of Vascular Reactivity in Cadmium-poisoned Rabbits)

  • 홍기환;임병용
    • 대한약리학회지
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    • 제18권1호
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    • pp.23-31
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    • 1982
  • 1) 카드뮴(Cd) 중독가토(中毒家兎)의 전신동맥혈압(全身動脈血壓) 및 이곡혈관(耳穀血管)의 말초저항(末梢抵抗)은 비(非)중독 대조군에 비(比)하여 증가(增加)되었다. 2) Cd중독군 혈관의 전기자극 반응은 대조군혈관의 것에 비(比)하여 현저히 감약되어 있었다. 그러나 norepinephrine에 대(對)하여는 전자(前者)에서 super-sensitivity를 나타내었다. 3) Arachidonate에 의하여 전기자극반응이 대조군혈관에서는 억제되었으나 Cd중독군에서는 증가되었다. 그리고 $PGE_2$$PGF_{2{\alpha}}$에 의하여는 양군혈관 모두 반응이 억제되었다. 4. Indomethacin전처치 혈관은 대조군에서는 영향을 받지 않았으나 Cd중독군은 월등히 증가되었다. 5) 비(非)중독군 혈관을 PSS로 관류시는 전기자극반응이 영향을 받지 아니하였으나 $K^+-free\;PSS$로 바꾸었을 때는 항진되었고 norepinephrine 반응은 변화가 없었다. 이상의 결과(結果)로 Cd중독시 동맥압의 상승과 말초저항의 증가는 혈관운동의 조절기전에 변동이 초래되어 야기되었다고 생각한다.

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야생벼 Oryza minuta에서 유래한 수원506호의 흰잎마름병 저항성유전자에 대한 고찰 (Genetic Analysis on the Bacterial Blight Resistance Gene from a Wild Relative, Oryza minuta)

  • 정지웅;노태환;강경호;신영섭;김연규
    • 한국작물학회지
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    • 제56권2호
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    • pp.124-133
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    • 2011
  • 벼 흰잎마름병은 세계적으로 벼 재배치에서 가장 문제시되는 병해충의 하나이다. 우리나라의 경우 상습발생지를 중심으로 Xa1과 Xa3 이 저항성 유전자로 활용되었으나, 소수의 저항원이 집중적으로 활용됨으로 인해 최근 이병화가 급속히 진행되고 있다. 특히 최근 Xa1과 Xa3 모두를 침해하는 새로운 균계 K3a가 확인됨에 따라 새로운 저항성 유전자의 동정 및 활용의 중요성이 높아가고 있다. 국내육성 자포니카품종 화성벼와 야생벼 O. minuta 간의 종간교잡을 통해 확립된 수원506호의 흰잎마름병에 대한 유전분석을 실시하였다. 수원506호와 통일계 품종인 밀양23호간의 교잡을 통해 확보한 F2 개체들을 활용하여 흰잎마름균주 HB3011 의 접종에 따른 병반장의 변이와 유전자지도 작성에 사용된 SSR 마커의 유전자형간의 연관성분석을 수행하였다. 수원506호의 흰잎마름병 저항성을 지배하며 우성유전자로 작용하는 주동유전인자가 염색체 4변 하단에서 SSR 마커 RM255 에 의해 표지 되었는데, 해당 염색체영역은 Xa1과 Xa2 및 Xa22 등이 보고되었던 영역과 매우 유사할 것으로 추정되었다.

나이와 성별에 따른 지역사회 거주 노인에서 무증상 경동맥 죽상경화증에 대한 혈관위험인자 및 인지장애와의 관련성 (Age and Gender Differences in the Relationship of Cognitive Impairment, Vascular Risk Factors, and Subclinical Carotid Atherosclerosis from Community-based Elderly)

  • 김지희;박현영;김대원;변승재;문효정;이인;양충용
    • 동의생리병리학회지
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    • 제26권3호
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    • pp.399-407
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    • 2012
  • To evaluate age and gender differences in the relation of cardiovascular risk factors, cognitive impairment, and subclinical carotid atherosclerosis from aged people using by a cross sectional method. Sixty-nine healthy elders living in the community who had not previously undergone carotid ultrasonography were included. We conducted life style surveys, and cognitive function tests including Korean-mini-mental state examination (K-MMSE) and clinical dementia rating-Korean. Various biomarkers from blood were assessed; fasting insulin-like growth factor-1, lipid-profile, high sensitivity C-reactive protein, total homocysteine, glucose, insulin, Homeostasis model assessment (HOMA) for insulin resistance index, vitamin B12, and folate level. Carotid intima-media thickness (C-IMT), and plaques were measured using carotid ultrasonography and aortic ultrasonography, a valid index of atherosclerosis. For the elderly subjects (aged 65-82 years), cognition impairment was more prevalent in females while subclinical atherosclerosis was more prevalentin males. Increased C-IMT has been kept in males, and C-IMT shows increasing trend and the peak at about 80 year-old in females with increasing age. The significant correlations between C-IMT and many vascular risk factors including age, triglyceride, abnormal homocysteinein male, and K-MMSE, insulin, HOMA index and abnormal aortic ultrasonography in female were different in each gender, with the exception of homocysteine (p<0.05). This data suggests that there were differences of age and gender characteristics in terms of subclinical atherosclerosis, cognitive impairment and vascular risk factors in community-living elders. Further larger and longitudinal studies across entire age are required to better understand the effects of risk factors on subclinical atherosclerosis.

다공성 폴리우레탄을 이용한 동정맥 누관의 개발 (Development of U-shaped Arterialvenous Shunt Using Porous Polyurethane)

  • 정재승;김희찬;박광석;최진욱;민병구
    • 대한의용생체공학회:의공학회지
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    • 제20권2호
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    • pp.221-230
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    • 1999
  • 다공성 인공 혈관을 제조하기 위한 새로운 기술에 대하여 연구하였다. 제조방법을 달리하여 만든 다공성의 시편을 준비하여 여러 가지 물성을 비교하였다. 용매/비용매 교환법에 의한 다공성 부여 방법과 고분자 용액의 냉각에 따른 상전이 현상을 이용하여 고분자 용액의 농도와 냉각속도를 달리하여 인공 혈관 시편을 제작하였다. 고분자 용액의 농도가 감소할수록 그리고 냉각속도가 작을수록 인공 혈관 재료로서 유리한 물성을 지닐 수 있음을 알 수 있었다. 위의 방법으로 다공성을 조절함으로써 재료의 기계적 물겅 또한 조절할 수 있음을 알 수 있었다. 냉각 속도를 조절하여 다공성을 부여하는 방법을 이용하여, 고안된 몰드를 사용하여 기존에는 만들기 어려웠던 균일한 두게의 U자형 소구경 인공 혈관을 만들 수 있었다. 비교적 간단한 도구로 균일한 물성을 지니며 원하는 물성의 인공 혈관을 제조할 수 있었다. 온도를 조절하여 고분자 박막에 다공성을 부여하는 기술은 다양한 기능의 의료용 고분자에 접목하여 필요로 하는 기능성을 부여할 수 있는 중요한 기술로 이용할 수 있을 것이다.

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Korean Society of Heart Failure Guidelines for the Management of Heart Failure: Management of the Underlying Etiologies and Comorbidities of Heart Failure

  • Sang Min Park;Soo Youn Lee;Mi-Hyang Jung;Jong-Chan Youn;Darae Kim;Jae Yeong Cho;Dong-Hyuk Cho;Junho Hyun;Hyun-Jai Cho;Seong-Mi Park;Jin-Oh Choi;Wook-Jin Chung;Seok-Min Kang;Byung-Su Yoo;Committee of Clinical Practice Guidelines, Korean Society of Heart Failure
    • Korean Circulation Journal
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    • 제53권7호
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    • pp.425-451
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    • 2023
  • Most patients with heart failure (HF) have multiple comorbidities, which impact their quality of life, aggravate HF, and increase mortality. Cardiovascular comorbidities include systemic and pulmonary hypertension, ischemic and valvular heart diseases, and atrial fibrillation. Non-cardiovascular comorbidities include diabetes mellitus (DM), chronic kidney and pulmonary diseases, iron deficiency and anemia, and sleep apnea. In patients with HF with hypertension and left ventricular hypertrophy, renin-angiotensin system inhibitors combined with calcium channel blockers and/or diuretics is an effective treatment regimen. Measurement of pulmonary vascular resistance via right heart catheterization is recommended for patients with HF considered suitable for implantation of mechanical circulatory support devices or as heart transplantation candidates. Coronary angiography remains the gold standard for the diagnosis and reperfusion in patients with HF and angina pectoris refractory to antianginal medications. In patients with HF and atrial fibrillation, longterm anticoagulants are recommended according to the CHA2DS2-VASc scores. Valvular heart diseases should be treated medically and/or surgically. In patients with HF and DM, metformin is relatively safer; thiazolidinediones cause fluid retention and should be avoided in patients with HF and dyspnea. In renal insufficiency, both volume status and cardiac performance are important for therapy guidance. In patients with HF and pulmonary disease, beta-blockers are underused, which may be related to increased mortality. In patients with HF and anemia, iron supplementation can help improve symptoms. In obstructive sleep apnea, continuous positive airway pressure therapy helps avoid severe nocturnal hypoxia. Appropriate management of comorbidities is important for improving clinical outcomes in patients with HF.

성견의 연속 양측 폐이식을 이용한 폐보존 평가 연구 (Evaluation of Lung Preservation by Using of Canine Bilateral Sequential Lung Tranplantation)

  • 박창권;김재범;유영선;권건영;전석길;김정식
    • Journal of Chest Surgery
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    • 제33권5호
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    • pp.377-384
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    • 2000
  • Background: Numerous studies of safe, long term preservation for lung transplantation have been performed using ex vivo models or in vivo single lung transplantation models. However, a safe preservation time which is applicable for clinical use is difficult to determine. We prepared LPDG solution for lung preservation study. In this study we examined the efficacy of LPDG(low potassium dextran glucose) solution in 24-hour lung preservation by using a sequential bilateral canine lung allotransplant model. Material and Method: Seven bilateral lung transplant procedures were performed using weight-matched pairs(24 to 25kg) of adult mongrel dogs. The donor lungs were flushed with LPDG solution and maintained hyperinflated with 100% oxygen at 1$0^{\circ}C$ for a planned ischemic time of 24 hours for the lung implanted first. After sequential bilateral lung transplantation, dogs were maintained on ventilators for 3 hours: arterial resistance were determined if the recipients hourly after bilateral reperfusion and compared with pretransplant-recipient values, which were used as controls. After 2hours of reperfusion, the chest X-ray, computed tomogram and lung perfusion scan were performed for assessmint of early graft lung function. Pathological examinations for ultrastructural findings of alveolar structure and endothelial structure of pulmonary artery were performed. Result: Five of seven experiments successfully finished the whole assessments after bilateral reperfusion for three hours. Arterial oxygen tension in the recipients was markedly decrased in immediate reperfusion period but gradually recovered after reperfusion for three hours. The pulmonary artery and pulmonary vascular resistance showed singificant elevation(p<0.05 versus control values) but also recovered after reperfusion for three hours(p<0.05 versus immediate period value). The ultrastructural findings of alveolar structure and endothelial structure of pulmonary artery showed reversible mild injury in 24 hours of lung perservation and reperfusion. Conclusion : This study suggests that LPDG solution provides excellent preservation in a canine model in which the dog is completely dependent on the function of the transplanted lung.

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Ginsenoside Rg3의 항암효능 연구의 진보 (Recent Progress in Research on Anticancer Activities of Ginsenoside-Rg3)

  • 남기열;최재을;홍세철;표미경;박종대
    • 생약학회지
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    • 제45권1호
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    • pp.1-10
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    • 2014
  • Ginsenoside Rg3 (G-Rg3) is one of protopanaxadiol ginsenosides characteristic of red ginseng, steamed and dried ginseng (Panax ginseng), which has recently attracted much attention for its antitumor properties in vitro and in vivo animal models. Experimental studies have demonstrated that it could promote cancer cell apoptosis, inhibit cancer cell growth, the apoptosis of cancer cells, adhesion, invasion and metastasis, and also prevent an angiogenetic formation in prostate, breast, ovarian, colorectal, gastric, liver and lung cancer etc. It has shown the antitumor activities by modulation of diverse signaling pathways, including regulation of cell proliferation mediators (CDKs and cyclins), growth factors (vascular endothelial growth factor), tumor suppressors (p53 and p21), cell death mediators (caspases, Bcl-2, Bax), inflammatory response molecules ($NF-{\kappa}B$ and COX-2), protein kinases (JNK, Akt, and AMP-activated protein kinase) and Wnt/${\beta}$-catenin signaling. In addition, the combination of Rg3 and chemotherapeutic agents have synergistically enhanced therapeutic efficacy and reduced antagonistically side effects. Furthermore, it can reverse the multidrug resistance of cancer cells, prolong the survival duration and improve life quality of cancer patients. Taken together, accumulating evidences could provide the potential of G-Rg3 in the treatment of cancers and the feasibility of further randomized placebo controlled clinical trials.

대동맥 반사파를 재현한 4 element 대동맥 혈압 모델을 이용한 혈압 기반 진단 기술의 평가 (Estimation of Blood Pressure Diagnostic Methods by using the Four Elements Blood Pressure Model Simulating Aortic Wave Reflection)

  • 최성욱
    • 대한의용생체공학회:의공학회지
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    • 제36권5호
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    • pp.183-190
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    • 2015
  • Invasive blood pressure (IBP) is measured for the patient's real time arterial pressure (ABP) to monitor the critical abrupt disorders of the cardiovascular system. It can be used for the estimation of cardiac output and the opening and closing time detection of the aortic valve. Although the unexplained inflections on ABP make it difficult to find the mathematical relations with other cardiovascular parameters, the estimations based on ABP for other data have been accepted as useful methods as they had been verified with the statistical results among vast patient data. Previous windkessel models were composed with systemic resistance and vascular compliance and they were successful at explaining the average systolic and diastolic values of ABP simply. Although it is well-known that the blood pressure reflection from peripheral arteries causes complex inflection on ABP, previous models do not contain any elements of the reflections because of the complexity of peripheral arteries' shapes. In this study, to simulate a reflection wave of blood pressure, a new mathematical model was designed with four elements that were the impedance of aorta, the compliance of aortic arch, the peripheral resistance, and the compliance of peripheral arteries. The parameters of the new model were adjusted to have three types of arterial blood pressure waveform that were measured from a patient. It was used to find the relations between the inflections and other cardiovascular parameters such as the opening-closing time of aortic valve and the cardiac output. It showed that the blood pressure reflection can bring wide range errors to the closing time of aortic valve and cardiac output with the conventional estimation based on ABP and that the changes of one-stroke volumes can be easily detected with previous estimation while the changes of heart rate can bring some error caused by unexpected reflections.

비타민 E 투여가 마우스의 체액성 및 세포성 면역반응에 미치는 영향 -비타민 E 결핍환자의 간호중재 개발을 위한 동물실험 - (Effect of Vitamin E Treatments on The Humoral and Cellular Immune Responses in Mice. - Animal experiment for nursing care of vitamin E-deficient patients-)

  • 김금재
    • 대한간호학회지
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    • 제23권4호
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    • pp.528-543
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    • 1993
  • Vitamin E, which has its advocates in the treatment of diabetes mellitus. autoimmune disease, cancer and peripheral vascular and thromboembolic disease, has now been alleged to have a powerful antioxident effect and to affect various biological activities such as fertility factor, inhibition of human platelet aggregation and stabilization of biological membranes. The present study was designed to test whether vitamin I(alpha-tocopherol) can : (1) enhance the hemagglutinin response to sheep red blood cells (SRBC), (2) modulate Arthus and delayed type hypersensitivity(DTH) to SRBC and contact hypersensitivity to dinitrofluorobenzene (DNFB). (3) enhance the mitogenic response of murine splenocyte, (4) decrease the recovery of Cryptococcus neoformans from brain, lung, liver, spleen and kidney of infected mice and (5) have an inhibitory or enhancing effect on the induction of active systemic anaphylaxis(ASA) induced by chicken-gamma globulin (CGG) in mice. Mice were given either intramuscular injections of 0.3ml (300mg) of vitamin I before immunization or were infection for 10 consecutive days or were given by vitamin I esophageal intubation, 0.1ml(100mg), for 20 days before sacrifice for the mitogenic response experiments. It was found that vitamin E treated mice showed a significant enhancement in hemagglutinin response, Arthus reaction and DTH to SRBC and contact hypersensitivity to DNFB. There was no significant difference in the mitogenic response to phytohemagglutinin(PHA), but the response to concanavalin A(ConA) or pokeweed mitogem(PWM) was increased in vitamin E-treated mice. Interestingly, the vitamin E administration before C. neoformans infection decreased significantly the recovery of C. neoformans from brain lung, liver, spleen and kidney of the infected mice as compared with that of the control mice, strongly suggesting that vitamin E pretreatment may increase the resistance of mice to the fungal infection. Unexpectedly, vitamin E administration enhanced the production of CGG -induced ASA. Taken together, it can be concluded that vitamin I administration may in-crease the humoral and cellular immune response and resistance. to C. neoformans infection, but enhance the induction of ASA to CGG. Further studies are necessary to clarify the underlying mechanism accounting for these effects.

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