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

Although the introduction of cyclosporine-prednisone immunosuppression has improved early renal graft survival, chronic rejection remains a major cause of longterm graft dysfunction. This study retrospectively examined 69 cases of chronic rejection among 643 primary renal allograft recipients treated with cyclosporine-prednisone immunosuppression from July 1981 to October 1989. Chronic rejection was defined as a rejection episode diagnosed greater than 90 days posttransplantation with characteristics of progressive nonacute renal function deterioration, confirmed, in most cases, by renal biopsy. This group was compared with an equal-sized matched cohort. Among cadaveric recipients, 61 of 456 patients (13.4%) displayed chronic rejection, whereas among living-related recipients, 8 of 187 patients (4.3%) developed chronic rejection. The average time from the date of transplantation to diagnosis of chronic rejection was 15 +/- 14 months. One- and three-year graft survivals following diagnosis of chronic rejection were 51% (30/59) and 25% (13/51), respectively, compared with the cohort one- and three-year graft survivals of 98% (58/59) and 86% (32/37) at similar periods posttransplantation. HLA mismatch, PRA status, blood transfusion history, lipid levels, cyclosporine trough levels, incidence of prior acute rejection, and initial graft dysfunction were not significantly different between the chronic rejection group and the matched cohort. Hypertension and proteinuria were significantly associated with chronic rejection (P less than 0.001). Of 58 biopsies performed, findings solely consistent with chronic rejection were observed in 9 cases (15%) and "acute upon chronic" rejection in 49 cases (83%). Treatment of acute concomitants improved the renal function in 43% (27/63) by the time of hospital discharge. Nonetheless, at 12 months the incidence of improved renal function eroded to 22% (13/59), suggesting that the benefit was relatively short-lived. Although the overall incidence of chronic rejection in this group of cyclosporine-prednisone-treated patients was lower than previous azathioprine-prednisone cohorts, the clinical presentation and progression of chronic rejection was similar. Additionally, the incidence of chronic rejection within this series was lower among living-related recipients versus cadaveric recipients of donor organs.
 ...
PMID:Chronic rejection in primary renal allograft recipients under cyclosporine-prednisone immunosuppressive therapy. 199 27

Forty-one patients with aldosterone-producing adenoma (APA) were subjected to a dexamethasone suppression test (DST) before surgery. Serum cortisol and urinary excretion of 17-hydroxycorticosteroids were suppressed by dexamethasone in 39 patients [DST(+)]. In two patients (cases A and B), they were not suppressed [DST(-)]. Clinical manifestations of the two DST(-) patients were similar to those of DST(+) patients. Hypertension, hypokalemia, high serum aldosterone levels, and suppressed PRA were found in all of the patients. The cut surfaces of the adenomas from all of the patients, including cases A and B, were golden yellow, which is typical of APA. However, atrophies of the adjacent normal tissues were evident exclusively in the two DST(-) patients. After removal of the affected adrenals, the serum cortisol level was suppressed by dexamethasone in one of the DST(-) patients (case B). These findings suggested autonomous cortisol production by APA. To evaluate whether cortisol could be produced from the adenoma tissue, the presence of several steroidogenic enzymes was studied by immunohistochemistry and mRNA analysis in the adenomas and the adjacent nonneoplastic adrenals from the 2 DST(-) and 5 DST(+) patients. Immunohistochemical analysis demonstrated that steroidogenic enzymes were expressed in APA tumor tissues from both DST(-) and DST(+) patients. In both groups, mRNAs coding steroidogenic enzymes were present not only in the nonneoplastic but also in the tumor tissues. Quantitative analysis of the mRNA levels revealed that in the adrenals from DST(+) patients, the mRNAs were more abundant in nonneoplastic tissue than in tumor tissue. However, in those from DST(-) cases, the mRNAs were much more abundant in the tumor tissues than in the nonneoplastic tissues. These results indicate that tumor cells of the two DST(-) patients autonomously synthesized not only aldosterone but also cortisol. The diameters of the tumors from the two DST(-) patients exceeded 3 cm, while those from other DST(+) patients were smaller. In patients with large APA, adrenal insufficiency should be anticipated upon removal of the tumor.
 ...
PMID:Dexamethasone-nonsuppressible cortisol in two cases with aldosterone-producing adenoma. 199 11

A total of 42 patients with malignant arterial hypertension (MAH) were examined. Of these, 32 patients had essential hypertension (26 with normal renal function and 6 with renal failure treated by programmed hemodialysis) and 10 suffered from chronic glomerulonephritis. The patients were examined for central hemodynamics, hormonal background (plasma renin activity) (PRA), plasma aldosterone and cortisol concentration. 14 patients underwent closed puncture biopsy of the kidneys. All the patients manifested high PRA associated activation of gluco- and mineralocorticoid adrenal function along with the hyperkinetic syndrome. MAH was characterized by dramatic discrepancy between the stroke and cardiac indices and specific peripheral resistance. Nephrosclerosis whose extent varied, attaining maximum in patients with associated essential hypertension and renal failure and in autopsy material, in addition to severe lesions of the renal vessels appeared to be the common feature of all morphological alterations. Plasmic impregnation and fibrinoid necrosis of the arterioles were not detectable in all the patients, being of focal character. The same alterations were identified in the patients during exacerbation of glomerulonephritis and in the absence of MAH. The data obtained point to the nonuniformity of MAH. Four clinicomorphological variants of MAH are suggested.
 ...
PMID:[The malignant hypertension syndrome: incontrovertible and questionable truths]. 221 9

A direct radioimmunoassay (RIA) for plasma active renin concentration (ARC) was evaluated by using plasma samples obtained from hospitalized normal volunteers and hypertensive patients. The direct renin RIA was performed by using a pair of anti-renin monoclonal antibodies and a sandwich method. It is suggested that an agitator should be used during the incubation, because the magnetic solid phase was precipitated and could not be suspended well in plasmas. Further, the thawed reagents should not be used for the assay. A highly significant correlation (r = 0.96, p less than 0.01) was found between ARC and enzymatic activity of renin (PRA) in plasma samples obtained from hypertensive patients. The mean values of ARC were 22.8 +/- 3.6 pg/ml in normal subjects, 22.5 +/- 5.3 in patients with EH having medium levels of PRA, 113.7 +/- 11.7 in patients with renovascular hypertension, and undetectable in patients with primary aldosteronism. The results indicated good and reliable performance of the direct renin RIA, which is clinically useful to investigate the renin-angiotensin system.
 ...
PMID:Measurement of plasma active renin by solid phase radioimmunoassay using monoclonal antibodies. 224 3

It seems established that hypertension, to some degree, is a frequent consequence of cardiac transplantation. The hypertension occurs de novo and is not related to whether hypertension was present in association with the heart disease that led to the need for transplantation. The etiology of this hypertension is multifactorial and varies depending on the time that has ensued after transplantation. Acutely, it is primarily a problem related to intravascular volume expansion and persistently increased systemic vascular resistance. Although it may be modest in severity, it seems to be particularly resistant to therapy with most antihypertensive drugs. Moreover, the total "hyperbaric impact" of the hypertension is rendered greater because the blood pressure and heart rate in these patients with denervated hearts fails to show the usual 10 to 15 percent fall when recumbent/asleep at night, which occurs in normotensive individuals and in most with hypertension of other etiologies. The major factor in the persistence of the hypertension through the later stages post-transplantation appears to be the cyclosporine that is used as an immunosuppressive. Although cyclosporine has been the major contributor to reduced rejection in these individuals, and to their increasingly prolonged survival, it inevitably produces slowly progressive impairment of renal function. The damage to the kidney is reflected both in tubular as well as glomerular and vascular damage, with a steady fall in glomerular filtration and a rise in creatinine. From our studies it appears that the renal alterations are associated with a gradual rise in plasma renin activity and angiotensin II, which perhaps further damages the kidney and causes persistence of the increased systemic vascular resistance. The use of lower doses of cyclosporine during the ischemic phase in the kidney that immediately follows surgery and of reduced doses over time, often with azathioprine added, seems to minimize the renal damage, or at least to stabilize it and to slow progression of the renal dysfunction and hypertension. Treatment of the hypertension with conventional drugs has definite but limited value. Diuretics and vasodilators have been the mainstay of our approach during the early phases of the hypertension but our recent data indicate that ACE inhibitors may become relatively specific in management during the later phases of the post-transplantation period as PRA levels rise in response to vascular damage by cyclosporine. ACE inhibitors have inherent dangers that require careful monitoring.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Hypertension following orthotopic cardiac transplantation. 240 98

To determine whether clonidine treatment affects cardiopulmonary baroreflex induced sympathetic activation, we assessed the hemodynamic and hormonal responses to lower body negative pressure (LBNP) before and after 3 weeks of treatment with low-dose (0.2 mg daily) clonidine in eight older (mean age, 62 years) patients with established mild-to-moderate hypertension. Arterial pressure, heart rate (HR), forearm vascular resistance (FVR), plasma norepinephrine (NE), and renin activity (PRA) responses were assessed. Our results demonstrate that clonidine treatment had no effect on basal or stimulated PRA and plasma NE levels at baseline and during LBNP. Baseline FVR significantly decreased (48 +/- 3 to 35.5 +/- 6 U) and the FVR responses to LBNP were lower following clonidine therapy. Although baseline mean arterial pressure (MAP) and FVR as well as FVR responses to LBNP were lower after clonidine, the responses to tilt and cold pressor testing were unchanged. Thus clonidine appears to act via peripheral mechanisms, as well as by decreasing central sympathetic outflow to lower peripheral vascular resistance.
 ...
PMID:Reflex vasoconstrictor responses to cardiopulmonary baroreceptor unloading, head-up tilt, and cold pressor testing in elderly mild-to-moderate hypertensives: effect of clonidine. 245 65

The sympathetic nervous system involvement in the pathogenesis of human renovascular hypertension was studied in 10 hypertensive patients with unilateral renal artery stenosis, who underwent percutaneous transluminal angioplasty (PTA). Before PTA, systolic/diastolic BP readings were 185.3 +/- 7.8/123.2 +/- 5.1 mmHg, peripheral PRA values were 8.63 +/- 2.27 ngAl/ml/h, the ratio RVRR was 2.15 +/- 0.27, the ratio V1-IVC/IVC was 1.00 +/- 0.23 (V1 = PRA from the renal vein of the stenotic side, IVC = PRA from the inferior vena cava) and the ratio V2-IVC/IVC was 0.04 +/- 0.02 (V2 = PRA from the renal vein of the non-stenotic side); 30 min after successful PTA the respective values of the above measured parameters were: 144.2 +/- 6.7/98.2 +/- 3.1 mmHg (p less than 0.01), 8.13 +/- 2.21 ngAl/ml/h (p less than 0.005), 1.79 +/- 0.19 (p less than 0.01), 0.68 +/- 0.18 (p less than 0.001) and 0.06 +/- 0.02 (p less than 0.005). Peripheral plasma noradrenaline levels (plNA) were 0.694 +/- 0.058 ng/ml, plNA levels from the renal vein of the stenotic side were 0.962 +/- 0.108 ng/ml and plNA levels from the renal vein of the non-stenotic side were 0.759 +/- 0.092 ng/ml; 30 min after successful PTA the respective values were 0.518 +/- 0.055 ng/ml (p less than 0.01), 0.681 +/- 0.078 ng/ml (p less than 0.005) and 0.510 +/- 0.063 ng/ml (p less than 0.005). It is suggested that the reversal of chronic renal ischaemia by PTA induced statistically significant changes in the sympathetic nervous system activity, parallel to the changes of renin secretion.
 ...
PMID:Changes of plasma noradrenaline levels in the renal and systemic circulation after successful percutaneous transluminal angioplasty in renovascular hypertension. 252 71

Elevations of atrial natriuretic peptide (ANP) in congestive heart failure (CHF) and chronic obstructive lung disease (COLD) are presumably due to atrial hypertension, while secondary hyperaldosteronism in these patients is thought to result from diminished renal perfusion. The responsiveness of the ANP and renin (PRA)-aldosterone (PA) systems to acute increases in right atrial pressure has not been studied in these patients, but in normals a reciprocal relationship between ANP with PRA and PA has been shown. The authors monitored venous pressure (VP, reflective of right atrial pressure), ANP, PRA and PA in 15 stable COLD patients, seven stable CHF patients and three normal controls at baseline and after elevation of VP by antishock trousers. Inflation of the trousers resulted in increased VP and ANP (p less than 0.05): control ANP, 84 +/- 17 to 108 +/- 23 pg/ml; COLD ANP, 176 +/- 5 to 200 +/- 7; and CHF ANP, 388 +/- 20 to 499 +/- 37. PRA and PA were not suppressed by increasing ANP levels and the delta ANP/delta VP ratio was similar among groups. No intergroup differences in resting PRA and PA were noted, but PRA was higher (p = 0.007) and PA tended to be higher (p = 0.08) in a sub-group of six edematous patients, as compared with non-edematous patients and controls. These findings: (1) confirm previously reported ANP differences between COLD and CHF; (2) indicate that the ANP system remains responsive to physiologic manipulations in COLD and CHF; and (3) demonstrate that ANP and the PRA-PA axis are not reciprocally related in either group.
 ...
PMID:Atrial natriuretic peptide, renin and aldosterone in obstructive lung disease and heart failure. 252 64

To assess the hemodynamic characteristics in malignant hypertension, echocardiography was performed in 18 patients with malignant essential hypertension (MH-I, n = 9) and secondary hypertension (MH-II, n = 9). Patients with benign hypertension with or without left ventricular hypertrophy (n = 8 and 7, respectively), patients with hypertensive heart failure (n = 7) and normotensive volunteers (n = 10) were subjected to controls. Plasma noradrenaline (NA) and renin activity (PRA) were also measured prior to the antihypertensive therapy. There were no significant differences in the durations of hypertension before the malignant phase, and the mean arterial pressure between MH-I and MH-II. Although posterior wall thickness (PWTd) in MH-II was similar to that in MH-I, interventricular septal thickness (IVSTd) was less marked in MH-II. The plasma NA and PRA were markedly increased in both MH-I and MH-II. End-diastolic dimension (Dd) of the left ventricle was within normal range, but end-systolic dimension (Ds) was significantly increased in MH-I, MH-II and hypertensive heart failure. The moderate decreases in ejection fraction (EF) and mean velocity of circumferential fiber shortening (mVcf) were observed in both MH-I and MH-II. Marked decreases in EF and mVcf were also observed in patients with hypertensive heart failure. The relationship between systolic blood pressure and Dd/PWTd was shifted toward the right and upper portion of the normal relation in MH-I and MH-II. The present study demonstrated that the hemodynamic characteristics in malignant hypertension are an inappropriate left ventricular hypertrophy due to a marked increase in systolic stress; dilatation of the left ventricle in systole; and a moderate decrease in ventricular systolic function. It is suggested that a decrease in left ventricular systolic function in malignant hypertension might be due in part to a marked increase in the influence of neurohumoral factors on hemodynamics.
 ...
PMID:[Echocardiographic features of left ventricular hypertrophy and contractility in malignant hypertension]. 253 Mar 33

To evaluate the correlations occurring among plasma atrial natriuretic factor (ANF), renin activity (PRA), aldosterone (ALD) and urinary kallikrein (KK) in young hypertensives and in young normotensives with or without a family history of hypertension, 26 essential hypertensives (mean age: 22.5 +/- 2), 21 normotensives (mean age: 22.3 +/- 1.9) and 13 normotensives with hypertensive heredity (mean age 22 +/- 1.8) under normal Na+ intake (120 mEq/daily) were studied. Blood samples for plasma ANF, PRA and ALD evaluations were taken after a night bed sleep (A) and again after 1 hour of deambulation (B). KK was evaluated on 24 hours urine specimens by the chromogenic substrate (S-2266) method. The results showed that ANF plasma levels in hypertensives (A = 44.5 +/- 19.4 pg/ml, B = 24.1 +/- 11 pg/ml) were higher than in normotensives (A = 38.3 +/- 19.4 pg/ml, B = 19.9 +/- 10.6 pg/ml), with a percentage difference of 13.8% in A situation and 17.4% in B situation. Moreover ANF was higher in normotensives with hypertensive heredity than in normotensives without heredity (A = +7.4%; B = +10%). In B situation ANF was inversely correlated with ALD in all groups (p less than 0.001 in hypertensives; p less than 0.05 in both groups of normotensives), and with PRA in hypertensive group (p less than 0.001). KK was significantly lower in hypertensives than in normals (p less than 0.01) showing only in hypertensive patients an inverse correlation with ANF (r = -0.60; p less than 0.001). In conclusion, our data indicate that raised levels of plasma ANF may be present in young hypertensives with low levels of PRA, ALD and KK.
 ...
PMID:[Relation of atrial natriuretic peptide, the renin-angiotensin-aldosterone system and kinin system in hypertensive and normotensive youngsters with or without a family history of essential arterial hypertension]. 253 Apr 12


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>