Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the recent years, a tremendous amount has been learned about the pathophysiology of atrial fibrillation (AF). AF induces electrophysiological changes in the atria causing a perpetuation of the arrhythmia ("electrical remodeling"). Besides such AF-induced electrophysiological changes, which involve the downregulation of L-type calcium channels and thereby the calcium inward current, AF induces structural and ultrastructural changes in atrial tissue ("structural remodeling"). Calcium-dependent tissue alterations are induced by proteases and phosphatases like calpain and calcineurin. Furthermore, cardiac diseases like hypertension, heart failure, etc. activate the atrial angiotensin II system, and thereby, a progressive pro-arrhythmogenic atrial fibrosis is induced. Besides first clinical trials assessing the antiarrhythmic effects of angiotensin II receptor blockers in patients with AF, experimental data suggest that viral gene transfer can be used to transform fibroblasts to electrically conducting cardiomyocytes. This highly interesting methodology may be helpful to restore electrical conduction in fibrotic cardiac tissue.
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PMID:[Morphological remodeling in atrial fibrillation]. 1673 31

Heart failure is a growing epidemic, with systemic hypertension a major risk factor for development of disease. However, the molecular determinants that prevent the transition from a state of hypertensive load to that of overt cardiac failure remain largely unknown. Here in experimental hypertension, knockout of the KCNJ11 gene, encoding the Kir6.2 pore-forming subunit of the sarcolemmal ATP-sensitive potassium (K(ATP)) channel, predisposed to heart failure and death. Defective decoding of hypertension-induced metabolic distress signals in the K(ATP) channel knockout set in motion pathological calcium overload and aggravated cardiac remodeling through a calcium/calcineurin-dependent cyclosporine-sensitive pathway. Rescue of the failing K(ATP) knockout phenotype was achieved by alternative control of myocardial calcium influx, bypassing uncoupled metabolic-electrical integration. The intact KCNJ11-encoded K(ATP) channel is thus a required safety element preventing hypertension-induced heart failure, with channel dysfunction a molecular substrate for stress-associated channelopathy in cardiovascular disease.
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PMID:KCNJ11 gene knockout of the Kir6.2 KATP channel causes maladaptive remodeling and heart failure in hypertension. 1678 3

Ongoing improvements in survival following liver transplantation have necessitated a re-evaluation of immunosuppression protocols. Corticosteroids and calcineurin inhibitors (CNIs) are the most frequently used immunosuppressive drugs for liver transplantation but are associated with a wide range of adverse effects, such as hypertension, hyperlipidemia and nephrotoxicity. The need for hemodialysis after liver transplantation is associated with poor outcomes. Renal dysfunction in this setting may be caused by pre-existing renal disease, hepatorenal syndrome and/or post-transplant factors, including the use of nephrotoxic drugs, most notably CNIs such as cyclosporine and tacrolimus. The methods that address this problem include the diligent control of metabolic factors (eg, hypertension and hyperlipidemia), therapeutic monitoring of CNIs and withdrawal or reduction of the dosage of CNIs, combined with the use of newer non-nephrotoxic agents. Although there is no clear consensus about the most effective strategy, the optimal long-term immunosuppressive regimen would prevent rejection without causing nephrotoxicity or other significant adverse effects. Recent evidence suggests that the liver is a tolerogenic organ and that some patients may need little, if any, long-term immunosuppression.
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PMID:Renal dysfunction in liver transplantation: the problem and preventive strategies. 1680 24

The calcineurin inhibitors (CNIs) ciclosporin (CsA) and tacrolimus are currently an important part of immunosuppressive regimens, but are associated with increased cardiovascular risk factors, including hyperlipidaemia, hypertension and diabetes mellitus. Conversion from CNI-based regimens to proliferation signal inhibitors or mammalian target of rapamycin inhibitors, such as everolimus and sirolimus, has been associated with an improvement in cardiovascular risk. This case study describes a 59-year-old renal transplant recipient who presented with angina pectoris while receiving immunosuppression with CsA, azathioprine and steroids. The patient developed angina pectoris 5 years after receiving a cadaveric renal transplant. At the time, the patient was obese, with hypertension controlled with diuretics and calcium channel blockers, and hyperlipidaemia controlled with statins. A scintigram revealed plurisegmental myocardial ischaemia, and a coronary angiogram showed the presence of occlusions in the left anterior descending artery and circumflex coronary artery. The patient also had 70% stenosis of the right coronary artery, which was corrected by angioplastic percutaneous intervention. The patient was converted from azathioprine to sirolimus 2 mg/day (trough blood level, 6-10 ng/ml), while the CsA dose was tapered and withdrawn. The angina pectoris subsequently resolved, no progression of coronary artery disease (CAD) has been observed during follow-up and stable renal function has been maintained throughout. Conversion to an immunosuppressive regimen of sirolimus with CsA withdrawal, along with angioplastic percutaneous correction of right coronary artery stenosis, therefore led to the complete resolution of angina pectoris and no progression of the CAD was noticed in this obese renal transplant patient with drug-controlled hypertension and hyperlipidaemia.
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PMID:Conversion to a proliferation signal inhibitor in a patient with coronary artery disease--a case report. 1681 56

Although IGF-II activating the IGF-II receptor signaling pathway has been found to stimulate cardiomyocyte hypertrophy, the role of IGF-II in cardiac cell apoptosis remains unclear. This study aimed to identify the roles of IGF-II and/or IGF-II receptors (IGF-II/IIR) in cardiomyoblast apoptosis and in hypertensive rat hearts with abdominal aorta ligation. Cultured rat heart-derived H9c2 cardiomyoblasts and excised hearts from Sprague-Dawley rats with 0- to 20-day complete abdominal aorta ligation, a model of ANG II elevation and hypertension, were used. IGF-II/IIR expression, caspase activity, DNA fragmentation, and apoptotic cells were measured by RT-PCR, Western blot, agarose gel electrophoresis, and TUNEL assay following various combinations of ANG II, IGF-II/IIR antibody, CsA (calcineurin inhibitor), SP-600125 (JNK inhibitor), SB-203580 (p38 inhibitor), U-0126 (MEK inhibitor), or Staurosporine (PKC inhibitor) in H9c2 cells. ANG II-induced DNA fragmentation and TUNEL-positive cells were blocked by IGF-II/IIR antibodies and antisense IGF-II, but not by IGF-II sense. IGF-II-induced apoptosis was blocked by IGF-IIR antibody and CsA. The increased gene expressions of IGF-II and -IIR induced by ANG II were reversed by U-0126 and Sp600125, respectively. Caspase 8 activities induced by ANG II were attenuated by U-0126, SP-600125, and CsA. DNA fragmentation induced by ANG II was totally blocked by SP-600125, and CsA and was attenuated by U-0126. In rats with 0- to 20-day complete abdominal aorta ligation, the increases in IGF-II/IIR levels in the left ventricle were accompanied by hypertension as well as increases in caspase 9 activities and TUNEL-positive cardiac myocytes. ANG II-induced apoptosis was reversed by IGF-II/IIR blockade and coexisted with increased transactivation of IGF-II and -IIR, which are mediated by ERK and JNK pathways, respectively, both of which further contributed to cardiomyoblast apoptosis via calcineurin signaling. The increased cardiac IGF-II, IGF-IIR, caspase 9, and cellular apoptosis were also found in hypertensive rats with abdominal aorta ligation.
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PMID:Roles of insulin-like growth factor II in cardiomyoblast apoptosis and in hypertensive rat heart with abdominal aorta ligation. 1682 5

Estrogen exerts complex biological effects through the two isoforms of estrogen receptors (ERs): ERalpha and ERbeta. Whether through alteration of gene expression or rapid, plasma membrane-localized signaling to non-transcriptional actions, estrogen-activated ERs have significant implications in cardiovascular physiology. 17-beta-estradiol (E2) generally has a protective property on the vasculature. Estrogen treatment is anti-atherogenic, protecting injured endothelial surfaces and lowering LDL oxidation in animal models. Increased NO production stimulated by E2 results in vasodilation of the coronary vascular bed, and involves rapid activation of phosphotidylinositol-3 kinase (PI3K)/Akt signaling to eNOS in carotid and femoral arteries. Both isoforms of ERs impact various vascular functions, modulating ion channel integrity, mitigating the response to arterial injury, inducing vasodilation, and preventing development of hypertension in animal models. In addition to reducing afterload by vasodilation, ERs have a direct antihypertrophic effect on the myocardium. E2-activated ERs (E2/ER) antagonize the hypertrophic pathway induced by vasoactive peptides such as angiotensin II by activating PI3K, subsequent MICIP gene expression, leading to the inhibition of calcineurin activity and the induction of hypertrophic genes. In models of ischemia-reperfusion, E2/ER is antiapoptotic for cardiomyocytes, exerting the protective actions via PI3K and p38 MAP kinases and suppressing the generation of reactive oxygen species. In sum, E2-activated ERs consistently and positively modulate multiple aspects of the cardiovascular system.
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PMID:Estrogen signaling in the cardiovascular system. 1686 19

Pediatric solid organ transplantation is so successful that >80% of children will survive to become teenagers and adults. Therefore, it is essential that these children maintain a good quality life, free of significant long-term side effects. While intensive immunosuppressive regimens (containing CsA, tacrolimus, MMF, and steroids) effectively reduce acute or chronic rejection, they can produce long-term side effects including viral infection, renal dysfunction, hypertension, and stunting. The development of effective methods of diagnosis, prevention, and treatment of CMV means that this is no longer a significant cause of mortality, but morbidity remains high. In contrast, infection rates of EBV remain high in EBV-negative pre-transplant patients. However, pre-emptive reduction of immunosuppression or treatment with rituximab or adoptive T-cell therapy is effective in preventing/treating post-transplant lymphoproliferative disease. Recent protocols have concentrated on reducing CsA immunosuppression, to prevent unacceptable cosmetic effects, and to reduce the hypertension, hyperlipidemia, and nephrotoxicity. Both CsA and tacrolimus cause a 30% reduction in renal function, with 4-5% of patients developing severe chronic renal failure. The use of IL-2 inhibitors for induction therapy with low-dose calcineurin inhibitors, in combination with renal-sparing drugs such as MMF or sirolimus for maintenance immunosuppression, should prevent significant renal dysfunction in the future. The concept of steroid-free immunosuppression with IL-2 inhibitors, tacrolimus, and MMF is an attractive option, which may reduce stunting and renal dysfunction. However, these regimens may be associated with the increased development of de-novo autoimmune hepatitis in 2-3% of children. The most important challenge to long-term survival in transplanted children is the management of non-adherence and other adolescent issues, particularly when transferring to adult units, as this is the time when many successful transplant survivors lose their grafts.
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PMID:Current issues in pediatric transplantation. 1691 96

Chronic Allograft Nephropathy (CAN) is one of the most common cause of kidney transplant loss. CAN may be caused by immunologic as well as nonimmunologic factors which may interfere and increase response. Immunologic factors include acute rejection, degree of HLA mismatch, inadequate immunosuppression. Nonimmunologic factors contain delayed graft function, ischemia-reperfusion injury, nephrotoxicity of calcineurin inhibitors, hyperfiltration, hypertension and hyperlipidemia. The histopatological description of CAN may indicate two phases of injury. An initial phase by one year include tubulointerstitial infiltration in the late phase of CAN arteriolar hyalinosis and glomerulosclerosis were revealed. Modification of the immunosuppressive treatment with reduction or withdrawal of calcineurin inhibitors may prevent graft loss, while addition of nonnephrotoxic agents such as mycophenolate mofetil or sirolimus should be considered by the risk of acute rejection. Additionally effective management by hypertension and hyperlipidemia is essential.
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PMID:Chronic allograft nephropathy--immunologic and nonimmunologic factors. 1702 23

Both calcineurin inhibitors (CNIs), cyclosporine and tacrolimus, are widely used in pediatric liver transplant recipients and currently data are limited with regards to long-term results using the one drug or the other in comparable low doses. We conducted the present study to assess the advantages and disadvantages of both drugs in children at least five yr post-liver transplantation. A total of 129 children were enrolled in the study. Thirty-eight of the children were switched to tacrolimus monotherapy for different reasons [steroid resistant graft rejection (n = 15), chronic rejection (n = 5), severe acute rejection (n = 4), repetitive acute graft rejection (n = 5), dysfunction of the transplant (n = 3), insufficient CsA metabolism (n = 3), hypertrichosis (n = 2), and CsA toxicity (n = 1)], four patients had primary tacrolimus therapy, and 87 patients are receiving cyclosporine. Mean trough levels were 5.3 +/- 2.3 ng/mL (tacrolimus) and 73.6 +/- 44.5 micro/L (cyclosporine), respectively at least five yr post-orthotopic liver transplantation (OLT). There was no significant difference in the calculated glomerular filtration rate between children on cyclosporine and tacrolimus (142.7 + 39.5 mL/min/1.73 m(2) vs. 151.1 +/- 44.1 mL/min/1.73 m(2)). The incidence of arterial hypertension was 7.1% vs. 9.2%, that of hepatotoxicity was 0% vs. 2.3%. Cosmetic changes were found in more than one-third of the patients on cyclosporine and in 4.8% of the patients receiving tacrolimus. Quality of life was excellent in both groups (self assessment). The impact of CNIs on chronic graft dysfunction cannot be assessed by our present study. We conclude from the results that cyclosporine and tacrolimus are both excellent drugs for maintenance immunosuppression in the long-term course following pediatric liver transplantation. However, this retrospective analysis is limited by the bias between children on CsA as compared with patients receiving tacrolimus. A prospective randomized controlled trial is needed in order to assess which CNI is the best for children following OLT.
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PMID:Long-term evaluation of cyclosporine and tacrolimus based immunosuppression in pediatric liver transplantation. 1709 62

Enormous advancements in visceral transplantation have led to significant improvements in the quality of life of patients. However, despite these developments, the average graft half-life after transplantation has remained almost unchanged and chronic rejection is still considered a major problem. In this regard, more concerns have shifted to factors influencing long-term graft survival, patient survival, and quality of life. To achieve this goal, detrimental effects of immunosuppressive (IS) agents, which have deleterious influence on the quality of life and/or patient survival, should be reduced. In the course of recent years, the transplant community has worked on reducing these side effects by developing new ISs, employing new combination regimens, or finding and adjusting optimal dosages and blood level concentrations. Among the IS agents, the antifungal, antitumoral and IS activity of mammalian target of rapamycin (mTOR) inhibitors without nephrotoxicity, have received special attention regarding this new class of IS. Sirolimus (SRL), as the first member of mTOR inhibitors, has been utilized in many clinical trials with respect to its benefit-risk assessment. In our review, the clinical evolution of SRL, as well as the evidence-based clinical benefits of SRL in kidney and liver transplantation (KTx, LTx), are summarized. Various studies of SRL in KTx and LTx have shown that combination therapy with SRL will enrich the variety of IS modalities. It also can be regarded as a safe base therapy to which other necessary drugs can be added. In addition to the enhanced acute rejection prophylaxis, and in contrast to the calcineurin inhibitors (CNI) and steroids, this drug solely does not have common side effects such as nephrotoxicity, neurotoxicity, diabetes mellitus and hypertension. Moreover, this agent might diminish vasculopathic processes that mediate chronic allograft nephropathy (CAN). Therefore, by reducing the likelihood of CAN it can decrease the rate of long-term organ failure. One possibly desirable characteristic of SRL is its antiproliferative effect, which could provoke antitumoral or antiatherogenic activity following transplantation. Despite all promising impacts of SRL in organ transplantation, there are some concerns regarding the adverse effects of this drug, for instance dyslipidemia, pneumonitis and wound healing problems. However, the majority of these side effects can be reduced or ceased by careful dose adjustments and correct timing of use. In conclusion, after a decade of both in vivo and in vitro studies on SRL, it can be advocated that SRL is a promising, potent and effective IS agent as it reduces the rate of acute rejection episodes in de novo transplants. It could improve the quality of life, graft and patient survival rate, and achieve excellent outcomes with few adverse effects when wisely used in combination with other immunosuppressants.
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PMID:The role and value of sirolimus administration in kidney and liver transplantation. 1710 Jun 99


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