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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The use of a single lung transplant, modified with removal of the middle lobe of the donor right lung, has been described for a term neonate with respiratory distress secondary to right-sided congenital diaphragmatic hernia. The successful transplant allowed the patient to be successfully weaned from extracorporeal membrane oxygenation. Because of the early age of the patient at transplantation (3 weeks), it was unclear how the patient's left lung would develop, and there was uncertainty regarding the risk of life-time immunosuppression. By the age of 4 years, 10 months, she was demonstrating some failure to thrive, hypertension, and hirsutism, obvious side effects of chronic immunosuppression. The question was raised as to the potential for transplant pneumonectomy. A ventilation-perfusion scan demonstrated a decrease of right lung ventilation compared with the immediate postoperative period (27% versus 43%); right heart catheterization with balloon occlusion of the right main pulmonary artery suggested that the patient would tolerate right pneumonectomy. After discussion with the family, the patient underwent transplant pneumonectomy via a right posterolateral approach. Findings at the time of operation included mild to moderate adhesions as well as recurrence of the diaphragmatic hernia. She tolerated the procedure well and was discharged home on the fifth postoperative day with cessation of her immunosuppression. The immediate and medium-term success of this procedure suggests the potential for temporizing transplantation as a palliation to promote survival until the remaining native lung can provide sufficient ventilation.
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PMID:Elective transplant pneumonectomy. 957 74

Severe low-renin hypertension has few known causes. Apparent mineralocorticoid excess (AME) is a genetic disorder that results in severe juvenile low-renin hypertension, hyporeninemia, hypoaldosteronemia, hypokalemic alkalosis, low birth weight, failure to thrive, poor growth, and in many cases nephrocalcinosis. In 1995, it was shown that mutations in the gene (HSD11B2) encoding the 11beta-hydroxysteroid dehydrogenase type 2 enzyme (11beta-HSD2) cause AME. Typical patients with AME have defective 11beta-HSD2 activity, as evidenced by an abnormal ratio of cortisol to cortisone metabolites and by an exceedingly diminished ability to convert [11-3H]cortisol to cortisone. Recently, we have studied an unusual patient with mild low-renin hypertension and a homozygous mutation in the HSD11B2 gene. The patient came from an inbred Mennonite family, and though the mutation identified her as a patient with AME, she did not demonstrate the typical features of AME. Biochemical analysis in this patient revealed a moderately elevated cortisol to cortisone metabolite ratio. The conversion of cortisol to cortisone was 58% compared with 0-6% in typical patients with AME whereas the normal conversion is 90-95%. Molecular analysis of the HSD11B2 gene of this patient showed a homozygous C-->T transition in the second nucleotide of codon 227, resulting in a substitution of proline with leucine (P227L). The parents and sibs were heterozygous for this mutation. In vitro expression studies showed an increase in the Km (300 nM) over normal (54 nM). Because approximately 40% of patients with essential hypertension demonstrate low renin, we suggest that such patients should undergo genetic analysis of the HSD11B2 gene.
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PMID:A genetic defect resulting in mild low-renin hypertension. 970 24

The most potent corticosteroids are 11beta-hydroxylated compounds. In humans, two cytochrome P450 isoenzymes with 11beta-hydroxylase activity, catalysing the biosynthesis of cortisol and aldosterone, are present in the adrenal cortex. CYP11B1, the gene encoding 11beta-hydroxylase (P450c11), is expressed on high levels in the zona fasciculata and is regulated by ACTH. CYP11B2, the gene encoding aldosterone synthase (P450c11Aldo), is expressed in the zona glomerulosa under primary control of the renin-angiotensin system. Aldosterone synthase has 11beta-hydroxylase activity as well as 18-hydroxylase activity and 18-oxidase activity. The substrate for CYP11B2 is 11-deoxycorticosterone, that of CYP11B1 is 11-deoxycortisol. Mutations in CYP11B1 cause congenital adrenal hyperplasia (CAH) due to 11beta-hydroxylase deficiency. This disorder is characterized by androgen excess and hypertension. Mutations in CYP11B2 cause congenital hypoaldosteronism (aldosterone synthase deficiency) which is characterized by life-threatening salt loss, failure to thrive, hyponatraemia and hyperkalaemia in early infancy. Both disorders have an autosomal recessive inheritance. Classical and nonclassical forms of 11beta-hydroxylase deficiency can be distinguished. Studies in heterozygotes for classical 11beta-hydroxylase deficiency show inconsistent results with no or only mild hormonal abnormalities (elevated plasma levels of 11-deoxycortisol after ACTH stimulation). In infants with congenital hypoaldosteronism, a comparable frequency of 18-hydroxylase deficiency (aldosterone synthase deficiency type I) and of 18-oxidase deficiency (aldosterone synthase deficiency type II) can be found. Molecular genetic studies of the CYP11B1 and CYP11B2 genes in 11beta-hydroxylase deficiency or aldosterone synthase deficiency have led to the identification of several mutations. Transfection experiments showed loss of enzyme activity in vitro. In some of the patients with 18-oxidase deficiency (aldosterone synthase deficiency type II) no mutations in the CYP11B2 gene were identified. Refined methods for steroid determination are the basis for the diagnosis of inborn errors of steroidogenesis. Molecular genetic studies are complementary; on the one hand, they have practical importance for the prenatal diagnosis of virilizing CAH forms and on the other hand, they are of theoretical importance in terms of our understanding of the functioning of cytochrome P450 enzymes. Copyrightz1999S.KargerAG, Basel
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PMID:Disorders of the aldosterone synthase and steroid 11beta-hydroxylase deficiencies. 1055 65

Chronic renal failure (CRF) is the irreversible deterioration of renal function that gradually progresses to end stage renal disease (ESRD). The chief causes of CRF include obstructive uropathy, primary glomerular diseases, reflux nephropathy and hypoplastic or dysplastic kidneys. Progressive hyperperfusion and hyperfiltration causes increasing glomerular injury and further renal damage. Symptoms of CRF are usually seen when GFR is between 10-25% of normal. Children with severe CRF often suffer from failure to thrive, growth retardation, acidosis, anemia and renal osteodystrophy. Management of CRF aims at retarding progression of renal damage and treatment of complications related to renal dysfunction. Measures suggested to retard progression include protein restriction, strict control of hypertension, use of angiotensin converting enzyme inhibitors and control of hyperlipidemia. Appropriate amounts of protein and calories are recommended to prevent growth failure. Nutritional supplements are often required. The availability of recombinant erythropoietin, calcitriol and human growth hormone has significantly improved the management of these patients. Once ESRD supervenes, renal replacement therapy in the form of chronic peritoneal or hemodialysis and transplantation is necessary.
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PMID:Evaluation and treatment of chronic renal failure. 1079 66

Pediatricians are in a unique place in society by being able not only to care for the health and well-being of mothers and which, are their clinical responsibility, but also by being able to act as advocates for those patients who are often among the most vulnerable of our population. This article illustrates some of these points by referring to Australian Aboriginals from the vast desert areas of Westerns Australia. In remote areas of Western Australia, Aboriginal infants have high rates of low birth weight, failure to thrive and undernutrition. They also have high rates of respiratory, gastrointestinal and other infections. Aboriginal infant mortality has improved significantly over recent years, but Aboriginal health and mortality rates are still much worse than those of non-Aboriginal children and tend to be worst in more remote parts of the state. Overall, Aboriginal infants less than one year in age were hospitalized 9.5 times more frequently than non-Aboriginal infants for respiratory diseases (such as pneumonia, acute bronchiolitis and asthma); diarrheal diseases and skin infections were other very important causes of hospitalization for Aboriginal infants. Another poorly understood aspect of Aboriginal health is their widespread proneness to urinary tract infections. This is very important now in Australian Aboriginals in whom end-stage renal failure is becoming very prevalent. Rapid social and lifesyle changes have been very important in the poor health status of Aboriginals. They are also subject to severe socio-economic discrimination, underemployment, limited education, overcrowding, social depression and severely depressed housing conditions, relative inaccessibility to adequate and nutritious foodstuffs, and limited access to clinical services. Aboriginal people are prone to obesity, hypertension, type-2 diabetes mellitus and cardiovascular diseases. Overuse of alcohol and tobacco smoking have also become important challenges, particularly among adolescents and young adults. For the past twenty years or so, special programs have been developed to help overcome some of these problems; these include immunization programs, an extensive child health care program, special childhood screening programs, and oral rehydration therapy to reduce the high rates of mortality and morbidity associated with diarrheal diseases. These improvements have been achieved despite a set of socio-economic circumstances that face Aboriginal infants and children who live with adverse social factors. This was termed "Down and Out in 1996" in an editorial in The New Scientist (27 January 1996). A strategy that Australian Aboriginals are using now is to increase their own role through Aboriginal-controlled health and medical services including child health programs.
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PMID:A pediatrician and his mothers and infants. 1086 86

Sleep-related breathing disorders in children are common. Nearly 10% of preschool-aged children snore, and 1% of 4- to 5-year-old children present with an obstructive sleep apnea syndrome (OSAS), mostly due to an adenotonsillar hyperplasia. OSAS in children differs markedly from adults concerning etiology, clinical symptoms, polysomnographic findings, and course of the disease. Therefore, results of adult sleep medicine cannot easily be applied to children. The disease may result in pulmonary or systemic hypertension, failure to thrive, and neurocognitive misbehavior. Up to now, there is no consensus concerning diagnosis and therapy. In this article, we summarize and discuss what is known so far about sleep-related breathing disorders in children, focussing on the OSAS as the most important diagnosis for the ENT specialist.
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PMID:[Sleep-associated respiratory disorders in childhood]. 1138 7

A girl with failure to thrive and a haemoglobin of 140 g/l at 1.3 years died from a brain haemorrhage 2.5 years later. Renal artery stenosis had caused severe, chronic hypertension and increased erythropoietin secretion (haemoglobin 182 g/l). Blood pressure should be measured in all unwell children, including those failing to thrive.
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PMID:Polycythaemia and hypertension caused by renal artery stenosis. 1191 16

Abdominal aortic coarctation and renal artery stenosis associated with neurofibromatosis is an unusual cause of renovascular hypertension in children and young adults. Sustained hypertension despite pharmacological treatment carries significant end-organ deterioration, failure to thrive, and potentially lethal complications. Timely arterial reconstruction can render these children normotensive, allowing normal development and reducing long-term morbidity. Progression of the arterial occlusive process, however, may occur after surgery. Therefore, careful follow-up is mandatory following aortorenal reconstruction in children with neurofibromatosis.
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PMID:Abdominal aortic coarctation, renovascular, hypertension, and neurofibromatosis. 1195 15

The effects of high blood pressure on growth are not fully understood and while hypertension may be associated with failure to thrive, hypertension causing failure to thrive in children is poorly documented. We describe four children presenting with failure to thrive due to hypertension consequent to various aetiologies. Control of hypertension with appropriate therapy resulted in improved growth. The exact pathogenesis of failure to thrive in hypertensive children is not known. These cases demonstrate the importance of careful measurement of blood pressure in children with failure to thrive.
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PMID:Hypertension: a cause of growth impairment. 1208 99

We describe an uncommon pediatric finding of unilateral renal artery stenosis, which presented as nephrotic syndrome, hypertension, failure to thrive, and hyponatremia. The child was a previously well 8-month-old male who looked well but had mild periorbital edema with severe hypertension. After 3 days of captopril therapy, the nephrotic-range proteinuria significantly improved. However, the hypertension persisted. Renal imaging revealed a small left kidney with reduced parenchymal uptake and no significant excretion. A renal angiogram demonstrated left renal artery stenosis with increased left renal vein renin activity. The hypertension resolved within 24 h of a left nephrectomy, but non-nephrotic-range proteinuria persisted for 8 months post operatively. Pathology of the left kidney was consistent with fibromuscular dysplasia. Although a few glomeruli (1%) had changes consistent with focal segmental glomerulosclerosis, such a few abnormal glomeruli were unlikely to account for the nephrotic syndrome. Hypertension-induced changes in the unaffected right kidney probably caused the nephrotic-range proteinuria.
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PMID:Renal artery stenosis and nephrotic syndrome: a rare combination in an infant. 1264 23


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