• 제목/요약/키워드: Vascular resistance

검색결과 185건 처리시간 0.025초

Blood cardioplegic solution을 사용한 선천성 복잡 심기형 환자의 술 후 조기 혈류학 변화에 관한 연구 (Early Postoperative Hemodynamic Changes in Patients of Congenital Complex Heart Disease using Blood Cardioplegic Solution)

  • 김영태;김용진
    • Journal of Chest Surgery
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    • 제25권11호
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    • pp.1192-1202
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    • 1992
  • Postoperative cardiac outputs and other hernoaynamic values were serially measured in fifteen patients of cyanotic congenital heart disease, after use of blood cardioplegic solution. Cardiac indices showed no change untill eight postoparative hours, then it began to decline to reach as low as 3.22$\pm$0.7L/min/m2 at 12 hours. After then gradual increse occ-ured to recover upto immediate postoperative value at 20 hours. Sharp decrese of heart rate and increse of systemic vascular resistance during 8~16 hours and steady increase of stroke indices during the whole study periods were observed. These observations suggested that the myocardium recovered gradually after open heart surgery, and that the decrease of cardiac indices during 8~16 hours could be a result of decrease of heart rates and increase of afterload. The changes of cardiac indices correlated with the changes of heart rate, postoperative time and mixed venous oxygen saturation [p<0.05]. No other hemodynamic values found to be in statistically significant correlation with the changes of cardiac indices. Left ventricular dysfunction seemed to occur more frequently during 8~12 hours, but it was not statistically significant. [p=0.73] In conclusion, great care must be taken during 2~3 days after the operation of cyanotic congenital heart disease, not to fall into a low cardiac output state, by maintaing adequate heart rates and reducing afterload especially when the systemic vascular resistance increases.

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Effects of anesthetics on resistive index of the medial long posterior ciliary artery and ophthalmic artery using color doppler imaging

  • Choi, Ho-jung;Lee, Young-won;Yoon, Jung-hee;Yeon, Seong-chan;Lee, Hyo-jong;Lee, Hee-chun
    • 대한수의학회지
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    • 제45권3호
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    • pp.423-427
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    • 2005
  • Color Doppler imaging (CDI) was carried out to evaluate the anesthetics effect on ophthalmic circulation using CDI-derived resistive index (RI) values. CDI was preformed on 24 dogs, and RI values were calculated for the medial long posterior ciliary artery (mLPCA) and ophthalmic artery (OA) before and after administration of anesthetics. After administration of benoxinate or acepromazine, a significant change of the mLPCA RI was not found. But, a significant decrease of the RI following ketamine (p < 0.001) or xylazine (p < 0.01) administration could be observed as compared with the self-control. Mean RI value of OA also showed this same trend. Intraocular pressure was significantly decrease following benoxinate (p < 0.01), acepromazine (p < 0.01), and xylazine (p < 0.001) administration within normal range. The results suggest that some anesthetics influence on ophthalmic vascular resistance. Therefore, chemical restraint was carefully used in clinical application of CDI-derived RI measurement. Particularly, benoxinate and acepromazine is useful chemical restraint without a change of the ophthalmic vascular resistance.

체위 변화에 수반되는 순환 및 호흡반응 (Circulatory and Respiratory Responses to Postural Changes)

  • 채의업;이석강;배성호
    • The Korean Journal of Physiology
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    • 제7권1호
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    • pp.13-21
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    • 1973
  • An attempt was made to study circulatory and respiratory responses to the passive tilt. Anesthetized dogs were tilted from horizontal to upright $(+90^{\circ})$ and head down $(-90^{\circ})$ position. The arterial blood pressure was decreased in the upright position and was decreased slightly in the head down position comparing to that in the horizontal position. Cardiac index also decreased in the both upright and head down positions. The total systemic vascular resistance was slightly increased in the upright position and was markedly increased in the head down position. The mean pulmonary arterial pressure was significantly decreased in the both upright and head down positions. The total pulmonary vascular resistance was decreased in the both upright and head down positions. Oxygen consumption was slightly decreased in the upright position, whereas it was slightly increased in the head down position. The A-V $O_2$ difference (vol. %) was slightly increased in the upright position and increased in the head down position. From the above results, process of the circulatory compensation to the gravity in the Passive tilting test was discussed. Neuronal cardiovascular regulation to the gravity and tile adaptation of capacitance vessles to hydrostatic stress and oxygen consumption concerning anoxic endurance of the brain were also discussed.

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Cognitive dysfunctions in individuals with diabetes mellitus

  • Kim, Hye-Geum
    • Journal of Yeungnam Medical Science
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    • 제36권3호
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    • pp.183-191
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    • 2019
  • Some patients with type 1 and type 2 diabetes mellitus (DM) present with cognitive dysfunctions. The pathophysiology underlying this complication is not well understood. Type 1 DM has been associated with a decrease in the speed of information processing, psychomotor efficiency, attention, mental flexibility, and visual perception. Longitudinal epidemiological studies of type 1 DM have indicated that chronic hyperglycemia and microvascular disease, rather than repeated severe hypoglycemia, are associated with the pathogenesis of DM-related cognitive dysfunction. However, severe hypoglycemic episodes may contribute to cognitive dysfunction in high-risk patients with DM. Type 2 DM has been associated with memory deficits, decreased psychomotor speed, and reduced frontal lobe/executive function. In type 2 DM, chronic hyperglycemia, long duration of DM, presence of vascular risk factors (e.g., hypertension and obesity), and microvascular and macrovascular complications are associated with the increased risk of developing cognitive dysfunction. The pathophysiology of cognitive dysfunction in individuals with DM include the following: (1) role of hyperglycemia, (2) role of vascular disease, (3) role of hypoglycemia, and (4) role of insulin resistance and amyloid. Recently, some investigators have proposed that type 3 DM is correlated to sporadic Alzheimer's disease. The molecular and biochemical consequences of insulin and insulin-like growth factor resistance in the brain compromise neuronal survival, energy production, gene expression, plasticity, and white matter integrity. If patients claim that their performance is worsening or if they ask about the effects of DM on functioning, screening and assessment are recommended.

Characterization of $ET_B$ Receptor-mediated Relaxation in Precontracted Mesenteric Artery from Streptozotocin-induced Diabetic Rats

  • Eom, Yang-Ki;Kim, Koan-Hoi;Rhim, Byung-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제9권5호
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    • pp.305-314
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    • 2005
  • Diabetes mellitus is associated with vascular complications, including an impairment of vascular function and alterations in the reactivity of blood vessels to vasoactive substances in various vasculature. In the present study, the authors have observed endothelin-B ($ET_B$) receptor agonist-induced relaxation in precontracted mesenteric arterial segments from streptozotocin (STZ)-induced diabetic rats, which was not shown from control rats or in other arterial segments from diabetic rats. Accordingly, the goal of this study was to investigate in what way STZ-induced diabetes altered reactivity of the mesenteric arterial bed and to examine the causal relaxation, if any, between this $ET_B$ receptor-mediated relaxation and endothelial paracrine function, especially nitric oxide (NO) production. The relaxation induced by $ET_B$ agonists was not observed in mesenteric arteries without endothelium. The relaxation to $ET_B$ agonists was completely abolished by pretreatment with BQ788, but not by BQ610. $N_{\omega}-nitro-L-arginine$ methyl ester and soluble guanylate cyclase inhibitors, methylene blue or LY83583 significantly attenuated the relaxant responses to $ET_B$ agonists, respectively. When the expression of eNOS and iNOS was evaluated on agarose gel stained with ethidium bromide, the expression of eNOS mRNA in diabetic rats was significantly decreased, but the expression of iNOS was increased compared with control rats. Furthermore, the iNOS-like immunostaining was densely detected in the endothelium and slightly in the arterial smooth muscle of diabetic rats, but not in control rats. These observations suggest that $ET_B$ receptor may not play a role in maintaining mesenteric vascular tone in normal situation. However, the alterations in $ET_B$ receptor sensitivity were found in diabetic rats and lead to the $ET_B$ agonist-induced vasorelaxation, which is closely related to NO production. In the state of increased vascular resistance of diabetic mesenteric vascular bed, enhanced NO production by activation of iNOS could lead to compensatory vasorelaxation to modulate adequate perfusion pressure to splanchnic area.

Expression, subcellular localization, and antioxidant role of mammalian methionine sulfoxide reductases in Saccharomyces cerevisiae

  • Kwak, Geun-Hee;Kim, Jae-Ryong;Kim, Hwa-Young
    • BMB Reports
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    • 제42권2호
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    • pp.113-118
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    • 2009
  • Despite the growing body of evidence suggesting a role for MsrA in antioxidant defense, little is currently known regarding the function of MsrB in cellular protection against oxidative stress. In this study, we overexpressed the mammalian MsrB and MsrA genes in Saccharomyces cerevisiae and assessed their subcellular localization and antioxidant functions. We found that the mitochondrial MsrB3 protein (MsrB3B) was localized to the cytosol, but not to the mitochondria, of the yeast cells. The mitochondrial MsrB2 protein was detected in the mitochondria and, to a lesser extent, the cytosol of the yeast cells. In this study, we report the first evidence that MsrB3 overexpression in yeast cells protected them against $H_2O_2$-mediated cell death. Additionally, MsrB2 overexpression also provided yeast cells with resistance to oxidative stress, as did MsrA overexpression. Our results show that mammalian MsrB and MsrA proteins perform crucial functions in protection against oxidative stress in lower eukaryotic yeast cells.

과당식이 고혈압 흰쥐에서 혈관 Endothelin-1과 산화질소합성효소의 발현 (Expression of Vascular Endothelin-1 and Nitric Oxide Synthase in Fructose-fed Hypertensive Rats)

  • 백윤웅;김명훈
    • 대한물리치료과학회지
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    • 제9권4호
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    • pp.45-52
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    • 2002
  • Rats that are fed a fructose-rich diet develop hypertension, insulin resistance, and hypertriglyceridemia. To elucidate whether altered expression levels of endothelin-1 and nitric oxide synthase are related to the development of insulin-resistant hypertension, we examined the present study. Male Sprague-Dawley rats were fed a fructose-rich diet for 5 weeks. Systolic blood pressure significantly increased in fructose-fed rats. While serum free fatty acid and plasma nitrite/nitrate levels did not significantly differ between the fructose-fed and control groups, plasma insulin and serum triglyceride concentrations significantly increased in the former. Endothelin-1 mRNA expression in the aorta increased in fructose-fed rats. Neither the protein expression of constitutive nitric oxide synthase nor that of inducible nitric oxide synthase were significantly affected by fructose feeding. However, nitrite/nitrate levels in the aorta were significantly increased. These results suggest that an increase in vascular endothelin-1 is an important contributing factor to the development of hypertension in fructose-fed rats. However, the vascular nitric oxide pathway may not be causally related to the development of fructose-induced hypertension.

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제2형 당뇨병 환자에서 인슐린저항성과 심혈관질환 위험요인 및 식이요인과의 관계 (The Association of Insulin Resistance with Cardiovascular Disease Risk and Dietary Factors in Korean Type 2 DM Patients)

  • 유소영;홍혜숙;이현숙;최영주;허갑범;김화영
    • Journal of Nutrition and Health
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    • 제40권1호
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    • pp.31-40
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    • 2007
  • The purpose of this study was to investigate the association between insulin resistance and cardiovascular disease risk factors in Korean type 2 diabetes patients. The subjects were 429 (male: 218, female: 211) type 2 DM patients visited DM clinic, and they were classified into quartiles based on $K_{ITT}$ index (%/min, Insulin Tolerance Test). Anthropometric and biochemical characteristics, and dietary intakes by Food Frequency Questionnaire were assessed. The means of waist circumference, fat mass, percent body fat and abdominal fat thickness were significantly higher in the lowest quartile (the most insulin resistant group) than in the highest quartile (the least insulin resistant group) of $K_{ITT}$ index (%/min)(p<0.05), For hematological values, the lowest quartile showed significantly higher fasting blood glucose, HbA1c, C-peptide, insulin, triglyceride, ApoB/apoA-1 ratio and C-reactive protein compared to the highest quartile (p < 0.05). Moreover, $K_{ITT}$ index (%/min) was negatively correlated with waist circumference, fat mass, percent body fat, abdominal fat thickness and fasting blood concentrations of glucose, HbA1c, C-peptide, insulin, cholesterol, triglyceride, ApoB/apoA-1 ratio and C-reactive protein (p < 0.05). Nutrient intakes were not significantly different among the quartile groups of $K_{ITT}$ index (%/min) and also not correlated with insulin resistance, however, they showed correlation with obesity parameters (BMI, waist circumference, waist-hip ratio, vat mass, abdominal fat thickness), which were strongly associated with insulin resistance. In conclusion, cardiovascular disease risk would be higher as the insulin resistance grows in Korean type 2 DM patients, and nutrient intakes would affect to the insulin resistance through the effect on anthropometric parameters.

운동과 신경가소성에 대한 고찰 (A Review of Exercise and Neural Plasticity)

  • 송주민
    • PNF and Movement
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    • 제6권2호
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    • pp.31-38
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    • 2008
  • Purpose: The purpose of this study were to overview the effect of exercise on neural plasticity and the proteins related to neural plasticity. Results: Exercise increased levels of BDNF(brain-derived neurotrophic factor), Insulin-like growth factor-I (IGF-I), Synapsin, Synaptophysin, VEGF(vascular endothelial growth factor) and other growth factors, stimulate neurogenesis, increase resistance to brain insult and improve learning and mental performance. These proteins improved synaptic plasticity by directly affecting synaptic structure and potentiating synaptic strength, and by strengthening the underlying systems that support plasticity including neurogenesis, metabolism and vascular function. Conclusion: Exercise-induced structural and functional change by these proteins can effect on functional movement, cognition in healthy and brain injured people and animals.

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Management of Persistent Pulmonary Hypertension in Preterm Infants

  • Lee, Byong Sop
    • Neonatal Medicine
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    • 제28권1호
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    • pp.1-6
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    • 2021
  • Persistent pulmonary hypertension of the newborn (PPHN) is a consequence of the failure of a decrease in the elevated pulmonary vascular resistance after birth. Pulmonary vasodilators, including inhaled nitric oxide (iNO), have been the mainstream of targeted therapy for PPHN, but no drugs have been proven to be effective in preterm infants with PPHN. The fetus remains hemodynamically stable despite lower arterial oxygen tension and pulmonary blood flow as compared to full-term newborns. This adaptation is due to the lower oxygen requirement and high oxygen-carrying capacity of fetal circulation. The immature lungs of preterm infants are more vulnerable to reactive oxygen species, and the response of pulmonary vascular dilatation to blood oxygen tension is blunted in preterm infants. Recently, iNO has been reported to be effective in a selected group of preterm infants, such as those with prolonged preterm rupture of membrane-oligohydramnios-pulmonary hypoplasia sequence. PPHN in preterm infants, along with maximum supportive treatment based on fetal physiology and meticulous assessment of cardiovascular function, is in dire need of new treatment guidelines, including optimal dosing strategies for pulmonary vasodilators.