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)

From 1986 to February 1993, 40 children aged 2 months to 18 years (average age 10.4 +/- 5.8 years) underwent heart transplantation. Indications for transplantation were idiopathic cardiomyopathy (52%), congenital heart disease (35%) with and without prior repair (71% and 29%, respectively), hypertrophic cardiomyopathy (5%), valvular heart disease (3%), and doxorubicin cardiomyopathy (5%). Patients were managed with cyclosporine and azathioprine. No prophylaxis with antilymphocyte globulin was used. Steroids were given to 39% of patients for refractory rejection, but weaning was always attempted and generally successful (64%). Five patients (14%) received maintenance steroids. Four patients died in the perioperative period and one died 4 months later. There have been no deaths related to rejection or infection. Average follow-up was 36 +/- 19 months (range 1 to 65 months). Cumulative survival is 88% at 5 years. In patients less than 7 years of age, rejection was monitored noninvasively. In the first postoperative month, 89% of patients were treated for rejection. Freedom from serious infections was 83% at 1 month and 65% at 1 year. Cytomegalovirus infections were treated successfully with ganciclovir in 11 patients. No impairment of growth was observed in children who underwent transplantation compared with a control population. Twenty-one patients (60%) have undergone annual catheterizations and no sign of graft atherosclerosis has been observed. Seizures occurred in five patients (14%) and hypertension was treated in 10 patients (28%). No patient was disabled and no lymphoproliferative disorder was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pediatric heart transplantation without chronic maintenance steroids. 831 43

We retrospectively studied 12 Japanese children (8 boys, 4 girls) with idiopathic membranous nephropathy (IMN), aged 2.9-15.8 (mean 7.7) years at onset. All patients were identified through either screening or a routine urinalysis; proteinuria was present in all, haematuria, which was macroscopic in 4, in 11. Three had nephrotic syndrome (NS) at or soon after onset. Stages on electron microscopy, performed in 10 patients, were I in 3, II in 5 and III in 2. Steroids alone or with cyclophosphamide were administered to 5 patients, including the 3 patients showing NS. Complete remission of proteinuria occurred in 8 patients 0.3-1.6 (mean 0.6) years after onset, and proteinuria did not recur. After a follow-up of 1.6-11.6 (mean 5.9) years, these 8 patients were in complete remission and the remaining 4 had only mild proteinuria; none had hypertension or impaired renal function. Thus, we infer that IMN in Japanese children may have a better course and outcome than IMN in non-Japanese children. Based on a comparative study of Japanese (previously reported cases added to ours) and non-Japanese (mostly Caucasian) children with IMN, this was confirmed; it is possible that steroid therapy in Japanese patients is more effective in inducing remission of NS and preserving renal function.
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PMID:Clinical course and outcome of idiopathic membranous nephropathy in Japanese children. 839 47

The spontaneously hypertensive rat (SHR) has a Y chromosome locus that increases blood pressure. This locus requires an androgen receptor and testosterone for maximum expression. Steroid sulfatase (STS) catalyzes the conversion of steroid sulfates to their active nonconjugated form. In some mammals the steroid sulfatase locus (Sts) is on the Y chromosome, although the rat Sts is on the X chromosome. We measured STS activity levels in SHR and normotensive Wistar Kyoto (WKY) males. SHR had significantly higher STS activity in testes, adrenal gland, liver, and hypothalamus. The Km values for STS in the two strains were not significantly different; thus, activity differences were likely due to differences in enzyme amounts. STS activity was measured in the backcross strains SHR/y and SHR/a to test and/or confirm a Y chromosome influence on STS. STS activity levels in these strains were intermediate between those of SHR and WKY. Because the blood pressures of SHR/y and SHR/a were also intermediate between SHR and WKY, the STS activity could be a secondary response to the hypertension. An alternative hypotheses is that a regulatory locus in addition to the structural locus is responsible for STS activity levels, and this regulatory locus is on the rat Y chromosome. Further study is needed to discriminate between these possibilities, and until the second hypothesis can be eliminated, the Sts locus or its modifier loci remain a potential component of the Y chromosome hypertensive locus.
Steroids 1995 Oct
PMID:Steroid sulfatase and the Y chromosome hypertensive locus of the spontaneously hypertensive rat. 853 76

11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD) modulates glucocorticoid interactions with mineralocorticoid and glucocorticoid receptors in vivo, by converting 11 beta-hydroxyglucocorticoids to their inactive 11-ketone derivatives. Defective 11 beta-oxidation of glucocorticoids has been associated with hypertension. The objective of this study was to investigate whether 11 beta-HSD contributes to the occurrence of hypertension in spontaneously hypertensive rats (SHRs). The liver and kidney microsomal oxidations of corticosterone (the physiological glucocorticoid in rats) in organs from juvenile (3 weeks old) and adult (3 months old) SHR and Wistar-Kyoto (WKY) rats, with NAD and NADP, show no differences between rat strains. For cortisol, with NADP, adult SHRs show (1.3-3 times; P < 0.05) lower kidney microsomal oxidation rates. The liver microsomal reduction of cortisone shows remarkable interstrain differences; with NADH, reduction is conducted only by adult WKY rats, whereas with NADPH, juvenile animals show similar reduction rates, but at adulthood, only WKYs reduce cortisone. Using Western blot analysis with antibodies against 11 beta-HSD1, positive signals are obtained only for liver microsomes, appearing somewhat lower in SHRs for juvenile but not adult animals. Urinary corticosterone/11-dehydrocorticosterone ratios (measured in adult animals) are not different between rat strains, but are elevated after administration of corticosterone in both strains (although significant only in SHRs). The data provide no indications for exaggerated stimulation of renal corticosteroid receptors, due to modified 11 beta-HSD, in SHRs. However, the experiments suggest the existence of multiple 11 beta-HSDs, in addition to 11 beta-HSD1 and 11 beta-HSD2, some of which may be modified in SHR, but the nature and physiological role of these 11 beta-HSDs is unclear.
Steroids 1995 Nov
PMID:Comparison of 11 beta-hydroxysteroid dehydrogenase in spontaneously hypertensive and Wistar-Kyoto rats. 858 2

Essential hypertensive patients often respond to treatments mitigating mineralocorticoid action, even though circulating levels of these steroids are within normal ranges. In addition to the kidney, mineralocorticoid or Type I receptors are found in the brain and vascular smooth muscle where they mediate effects associated with several forms of experimental hypertension. Studies in which discrete anatomic or functional areas of the brain have been ablated demonstrate that the periventricular areas of the hypothalamus and the central sympathetic and baroreceptor systems are crucial for the development of hypertension in the renoprival, DOCA salt, and Dahl salt-sensitive rat. Intracerebroventricular (i.c.v.) infusion of aldosterone in both rats and dogs at doses that do not raise serum levels above normal produce hypertension. The hypertension produced by systemic mineralocorticoid excess, adrenal regeneration, and i.c.v. or oral administration of glycyrrhetinic acid or carbenoxolone in genetically normotensive rats and by dietary salt in the Dahl salt-sensitive rat is inhibited by the i.c.v. infusion of a mineralocorticoid receptor antagonist or a Na+ channel-selective amiloride analog. Recent data demonstrate the extraadrenal synthesis of steroids in aortic endothelial cells, smooth muscle cells and the brain. The role of the extraadrenal synthesis of steroids raises new avenues for research into the causes of hypertension.
Steroids 1996 Apr
PMID:Mineralocorticoids, salt and high blood pressure. 873 97

The syndrome of apparent mineralocorticoid excess (AME) is a heritable form of hypertension due to an inborn error of cortisol metabolism and is characterized by hypokalemia and low renin levels despite subnormal or normal levels of aldosterone and other known mineralocorticoids. The syndrome is attributable to congenital deficiency of the enzyme 11 beta-hydroxydehydrogenase (11 beta-HSD), which converts cortisol (F) to biologically inactive cortisone. This results in a prolonged half-life of F, which acts at the kidney level as a potent mineralocorticoid (MC). In fact, both F and aldosterone have similar affinities in vitro for type I MC receptor (MR), and 11 beta-HSD activity protects the MR in vivo from the higher circulating levels of F. The biochemical marker of this disorder is an increased ratio of tetrahydrocortisol (THF) + allo-THF/tetrahydrocortisone (THE) in the urine, which has been found in more than 20 patients described to date, together with evidence of a more general defect in steroid ring A reduction. Only a few cases (the so-called type II form) described in Italy differ from the classic form having a normal THF/THE ratio, but in both forms the ratio of free urinary F/E has recently been found to be similarly high. Dexamethasone is the treatment of choice but is often inadequate in long term control of high blood pressure. Acquired forms of AME are those consequent on abuse of licorice or carbenoxolone, which both inhibit 11 beta-HSD; the latter also inhibits the reverse 11-oxoreductase reaction leading to somewhat different abnormalities of urinary cortisol/cortisone. So far, two isoenzymes of 11 beta-HSD have been purified and cloned; 11 beta-HSD type 1 is NADP-dependent, abundant in liver, lung, and testis, and catalyzes both 11 beta-dehydrogenation and 11 beta-oxoreduction; no mutation in its gene was detected in patients with AME. A second NAD-dependent isoenzyme is present in kidney and placenta and catalyzes dehydrogenation only. Very recently (1995) two groups have independently demonstrated the presence of mutations in its gene, located in chromosome 16q22. New and co-workers found a point mutation in exon 6 of two affected siblings of an Iranian family, while White and co-workers in parallel studies showed point mutations or small deletions in both alleles in nine unrelated patients; importantly, expression studies showed minimal or absent activity for almost all the mutant sequences. No definite mutations have been so far identified in patients with AME type II. AME is thus the third single gene cause of human hypertension to be described, after glucocorticoid remediable aldosteronism in 1992 and Liddle's syndrome in 1994.
Steroids 1996 Apr
PMID:Apparent mineralocorticoid excess: type I and type II. 873 99

The 11 beta-hydroxysteroid dehydrogenase type II enzyme (11 beta HSD2) converts cortisol to cortisone, allowing the non-selective mineralocorticoid receptor to bind aldosterone. When the activity of this enzyme is compromised, as occurs in licorice intoxication or in the congenital syndrome of apparent mineralocorticoid excess (AME), there is marked sodium retention, hypokalemia, and hypertension. The first proof that this enzyme was defective in AME came from the identification of the R337C mutation in a number of siblings with the syndrome. Subsequent expression studies showed that the mutant had a Km one order of magnitude higher than the wild-type enzyme while in the cell-free system it was without detectable activity. In the present work we have extended our studies on this mutant and provide evidence that the mutant protein may also partially inhibit the wild-type enzyme in heterozygotes. Furthermore, experiments incorporating the protein synthesis inhibitor cycloheximide show that the mutant enzyme is less stable than the wild-type activity in intact cells. These results suggest that mutations in the 11 beta HSD2 enzyme may have multiple consequences for the mineralocorticoid target cell.
Steroids 1996 Apr
PMID:The 11 beta-hydroxysteroid dehydrogenase type II enzyme: biochemical consequences of the congenital R337C mutation. 873

Recent studies have demonstrated that the interconversion of active and inactive glucocorticoids plays a key role in determining the specificity of the mineralocorticoid receptor and controlling local tissue glucocorticoid receptor activation. Two distinct isoforms of the enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) have been identified. 11 beta-HSD1 is NADPH-dependent and at its major site of action (the liver) is a reductase, converting cortisone to cortisol (11-dehydrocorticosterone to corticosterone in the rat). 11 beta-HSD2 is NAD-dependent, is present in tissues such as the kidney and placenta, and converts cortisol to cortisone (corticosterone to 11-dehydrocorticosterone in the rat). Congenital or acquired deficiency of 11 beta-HSD2 produces the syndrome of apparent mineralocorticoid excess (SAME) in which cortisol gains access to the unprotected nonspecific mineralocorticoid receptor. The congenital deficiency is associated with mutations in the gene encoding the kidney isoform of 11 beta-HSD2; the acquired form results from inhibition of the enzyme by licorice, carbenoxolone, ACTH-dependent steroids in the ectopic ACTH syndrome, and possibly circulating inhibitors of the enzyme. This paper focuses on recent evidence, which suggest that low levels of placental 11 beta-HSD2 result in increased exposure of the fetus to maternal glucocorticoid and low birth weight. In animal studies using the rat we have shown that birth weight is correlated positively and placental weight negatively with the level of placental 11 beta-HSD. Thus animals with low birth weight and large placentae were those likely to be exposed to the highest level of maternal glucocorticoid. In man a similar relationship was found with birth weight being significantly correlated either with placental 11 beta-HSD activity or with the extent of cortisol inactivation by isolated perfused placental cotyledons. Administration of dexamethasone (which is poorly metabolized by placental 11 beta-HSD2) to pregnant rats resulted in decreased birth weight and the development of hypertension in the pups when adult. The same results were obtained when pregnant rats were given carbenoxolone, an inhibitor of placental 11 beta-HSD2. Low protein diet during pregnancy in the rat resulted in low birth weight of the pups, increased placental weight but decreased placental 11 beta-HSD activity, and adult hypertension. Thus increased glucocorticoid exposure of the fetus secondary to a failure of the normal inactivation of maternal glucocorticoid by the placental may be an important mechanism linking changes in the in utero environment and common adult diseases.
Steroids 1996 Apr
PMID:11 beta-Hydroxysteroid dehydrogenases: key enzymes in determining tissue-specific glucocorticoid effects. 873 12

A 63-year old man presented with severe nephrotic syndrome and acute renal failure, accompanied by congestive circulatory insufficiency and hypertension. During the next four days, despite intense symptomatic treatment of nephrotic syndrome impairment of glomerular filtration continued to progress (serum creatinine rose from 6.5 mg/dl to 7.5 mg/dl) and 24-hour proteinuria reached 26.7 g, while proteinaemia was 43.7 g/l. After having excluded malignancy and systemic disease, patient was given two doses of methylprednisolone (750 mg every other day) along with haemodialyses on three consecutive days. On the fourth day dialyses were stopped due to development of poliuria. Patient's circulation parameters have improved and so did the renal function. Kidney biopsy revealed scarce glomerular proliferation and interstitial mononu: clear infiltrates. Steroids being continued (prednisone 50 mg on alternate days), patient's condition continued to improve, results of laboratory tests practically returned to normal and two subsequent hospital observations within monthly intervals confirmed stability of remission.
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PMID:[Fulminant course of glomerulonephritis with acute renal failure in a 63-year old man]. 883 51

We prospectively withdrew prednisone in 28 adult patients who had stable graft function more than 2 years after orthotopic liver transplantation (OLTx) and had been on 5 mg/d prednisone for at least 6 months. Prednisone was decreased from 5 mg/d to 2.5 mg/d for 1 month then stopped completely. Cyclosporine monotherapy was maintained at a level of approximately 200 ng/mL (TDX). Nineteen patients had prednisone withdrawn without complications. Four (14.2%) had modest elevations in liver function tests (two biopsy proven mild rejections and two were not biopsied). These four were treated with methylprednisolone boluses and then withdrawal of steroids again. Prednisone was restarted in five patients because of generalized fatigue and body aches (n = 4) and colitis (n = 1). Steroids later were successfully withdrawn in two of these patients. After prednisone withdrawal, three of five insulin-dependent diabetic patients were able to discontinue insulin therapy and their glycosylated hemoglobin levels improved. Four of fourteen hypertensive patients were able to discontinue antihypertensive medicines. Mean serum cholesterol decreased from 222.6 +/- 43.3 to 188.3 +/- 33.3 mg/dL (P < .001). The number of patients with serum cholesterol levels > 220 mg/dL decreased from 13 to 4. A control group of 24 patients maintained on 5 mg/d prednisone at least 2 years after liver transplantation also was studied. In this group during the study period, no diabetic became normoglycemic, no patient decreased their antihypertensive medicine, and the mean serum cholesterol levels did not change significantly. We conclude that prednisone withdrawal using cyclosporine monotherapy late after liver transplantation does not lead to graft loss and decreases the prevalence of diabetes, hypertension, and hypercholesterolemia. Symptoms occurring during withdrawal may be minimized by earlier or slower tapering.
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PMID:Prednisone withdrawal late after adult liver transplantation reduces diabetes, hypertension, and hypercholesterolemia without causing graft loss. 898 86


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