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Biomedical subjects

E Ritz

Publications and source records attributed to E Ritz.

At least 145 records · Page 8Linked to original sources
PubMed1999

Differential regulation of transforming growth factor receptors by angiotensin II and transforming growth factor-beta1 in vascular smooth muscle.

Angiotensin II (Ang II) and transforming growth factor (TGF) beta1 play a role in vascular remodeling in hypertension. In this process they may interact on various levels, including that of receptor regulation. This consideration prompted the present study on transcriptional regulation of TGF-beta receptors by Ang II and TGF-beta in vascular smooth muscle cells. Transcriptional expression of the components of the TGF-beta system was demonstrated for TGF-beta and for TGF-beta receptors I, II, and III. As measured by quantitative reverse transcriptase polymerase chain reaction, TGF-beta mRNA increased about 2.4-fold in the presence of 40 pM exogenous TGF-beta. Ang II at 10(-6) M increased TGF-beta mRNA 2.5-fold compared to control cells (P<0.05). Ang II also significantly increased TGF-beta protein concentration in the supernatant of confluent vascular smooth muscle cells. Ang II caused the induction of TGF-beta, but short-term experiments showed TGF-beta receptor II mRNA to be differentially regulated by Ang II and TGF-beta; while TGF-beta caused a 40% decrease in TGF-beta receptor II mRNA after 4 h (P<0.05), Ang II caused an increase by about 70%. In contrast, both TGF-beta and Ang II increased TGF-beta receptor I mRNA to about 260% or 180% of controls (P<0.05). TGF-beta effects were abrogated by coincubation with a TGF-beta neutralizing antibody, and Ang II effects were abrogated by losartan, an AT-1 receptor antagonist. Coincubation of Ang II with the TGF-beta neutralizing antibody did not inhibit the effect of Ang II, indicating that the short-term effects of Ang II on the expression of the TGF-beta receptors are not mediated via TGF-beta. Furthermore, Ang II stimulated DNA synthesis even in the presence of the TGF-beta neutralizing antibody. In conclusion, this study indicates (a) that in vascular smooth muscle TGF-beta receptors are regulated on the RNA level by TGF-beta and Ang II, and (b) that Ang II dependent regulation of TGF-beta receptors is at least partially independent of endogenous TGF-beta. Stimulation of the transcriptional expression of TGF-beta receptors by Ang II may increase sensitivity of vascular smooth muscle cells to TGF-beta.

Angiotensin II↗
PubMed1999

Peripheral blood mononuclear cells isolated from patients with diabetic nephropathy show increased activation of the oxidative-stress sensitive transcription factor NF-kappaB.

Increased oxidative stress and subsequent activation of the transcription factor NF-kappaB has been linked to the development of late diabetic complications. To determine whether oxidative stress dependent NF-kappaB activation is evident in patients with diabetic nephropathy we used an Electrophoretic Mobility Shift Assay based semiquantitative detection system which enabled us to determine NF-kappaB activation in ex vivo isolated peripheral blood mononuclear cells. We examined 33 patients with diabetes mellitus (Type I and Type II). Patients with diabetic nephropathy showed higher NF-kappaB binding activity in Electrophoretic Mobility Shift Assays and stronger immunohistological staining for activated NF-kappaBp65 than patients without renal complications. NF-kappaB binding activity correlated with the degree of albuminuria (r = 0.316) and with thrombomodulin plasma concentrations (r = 0.33), indicative for albuminuria associated endothelial dysfunction. In a 3 day intervention study in which 600 mg of the antioxidant thioctic acid (alpha-lipoic acid) per day were given to nine patients with diabetic nephropathy oxidative stress in plasma samples was decreased by 48% and NF-kappaB binding activity in ex vivo isolated peripheral blood mononuclear cells by 38%. In conclusion, activation of the transcription factor NF-kappaB in ex vivo isolated peripheral blood mononuclear cells of patients with diabetes mellitus correlates with the degree of diabetic nephropathy. NF-kappaB activation is at least in part dependent on oxidative stress since thioctic acid (alpha-lipoic acid) reduced NF-kappaB binding activity.

Adult↗
PubMed1999

Renal handling of drugs in the healthy elderly. Creatinine clearance underestimates renal function and pharmacokinetics remain virtually unchanged.

OBJECTIVE: It is commonly assumed that renal function, and in parallel the excretion of drugs, is considerably reduced in the elderly. Endogenous creatinine clearance or indirect estimates of this parameter are generally recommended for adapting drug dosage. The present study evaluates the validity of both assumptions. METHODS: We compared pharmacokinetics (and pharmacodynamics) of 50 mg atenolol, 800 mg piracetam and 25 mg hydrochlorothiazide plus 50 mg triamterene in ten healthy young [25 (2) years] and 11 healthy elderly subjects [68 (5) years]. Inulin (Cin) and para-aminohippurate [PAH (CPAH)] clearance (infusion clearance technique), endogenous (C(Cr)) and calculated (Cockroft-Gault) creatinine clearance, analysis of drugs and their metabolites (HPLC), were performed. Renal haemodynamics and the pharmacokinetics of beta-adrenergic blocking agent, diuretics and the nootropic agent piracetam, respectively, were measured on separate days. RESULTS: Cin was significantly (P < 0.01) lower in the healthy elderly subjects [104 (12) vs 120 (14) ml x min(-2) x 1.73 m(-2) in the young], but remained within the normal range (> 90 ml x min(-2) x 1.73 m(-2)). In contrast, C(Cr) was even lower in healthy elderly subjects [95 (24) vs 121 (20) ml x min(-1) in the young], and the Cockroft-Gault clearance underestimated true glomerular filtration rate (GFR) even more seriously [74 (17) vs 122 (16) ml min(-1)]. For atenolol the mean area under the curve (AUC) was similar in both groups [3.16 (0.48) microg x h(-1) x ml(-1) in the elderly vs 3.01 (0.30) in the young], as was the mean maximal plasma concentration [0.42 (0.07) vs 0.44 (0.06) microg x ml(-1)], but the proportion of the drug excreted in urine was marginally (P < 0.025) lower in the elderly. Similar results were obtained for hydrochlorothiazide, whereas no marked differences between the groups were found for triamterene and its metabolite. Furthermore, the pharmacodynamic action of diuretics was not significantly altered in the elderly. CONCLUSIONS: The true GFR of the healthy elderly remains within the normal range and is underestimated by creatinine clearance and more so by its surrogate (Cockroft-Gault clearance). In parallel, pharmacokinetics of renally excreted drugs are not affected in the healthy elderly to a clinically significant extent. For drugs with a narrow therapeutic window, indirect estimates of GFR appear to be an unreliable means for calculating correct dosage in the elderly.

Adrenergic beta-Antagonists↗
PubMed1999

End-stage renal failure in type 2 diabetes: A medical catastrophe of worldwide dimensions.

The incidence of patients with end-stage renal failure and diabetes mellitus type 2 as a comorbid condition has increased progressively in the past decades, first in the United States and Japan, but subsequently in all countries with a western lifestyle. Although there are explanations for this increase, the major factor is presumably diminishing mortality from hypertension and cardiovascular causes, so that patients survive long enough to develop nephropathy and end-stage renal failure. This review summarizes the striking differences between countries against the background of a similar tendency of an increasing incidence in all countries. Survival on renal replacement therapy continues to be substantially worse for patients with type 2 diabetes. A major reason for this observation is that patients enter renal replacement programs with cardiovascular morbidity acquired in the preterminal phase of renal failure. It is argued that the challenge for the future will be better patient management in earlier phases of diabetic nephropathy to attenuate or prevent progression, as well as cardiovascular complications.

Cross-Cultural Comparison↗
PubMed1999

Febrile lady with acute renal failure and desquamating erythema.

A 63-year-old woman developed acute renal failure and streptococcal toxic shock syndrome caused by streptococcus group G. Initially, an erythema resembling vasculitis was misleading. The subsequent clinical course, however, was typical for streptococcal toxic shock syndrome and met the criteria put forward by The Working Group on Severe Streptococcal Infections. In patients infected with streptococcus group G, toxic shock syndrome is rare. The streptococcus group G strains isolated from this patient did not produce pyrogenic exotoxins. Instead they produced an M-like protein related to group C and G streptococci that do not act as superantigens.

Acute Kidney Injury↗
PubMed1999

Physiological doses of calcium regulatory hormones do not normalize bone cells in uraemic rats.

BACKGROUND: Low bone turnover despite normal parathyroid hormone (PTH) concentrations has been found in many patients with end-stage renal failure. Hyporesponsiveness to the calcaemic action is also a known feature of uraemia. Hyporesponsiveness of bone surface cells involved in bone modelling has not been demonstrated to date. It was the purpose of this study using a rat model of moderate renal failure to investigate whether doses of PTH and calcitriol that reverse the effect of parathyroidectomy on calcaemia also normalize bone surface cell activity. MATERIALS AND METHODS: Sham-operated pair-fed male Spraque-Dawley rats were compared with subtotally nephrectomized (SNX), parathyroidectomized (PTX) rats that received either solvent or calcitriol (5 pmol kg -1 h-1) + 1,34 rat PTH (100 ng kg -1 h-1) by osmotic mini-pump. Histomorphometric measurements were carried out in the vertebral body (L5). RESULTS: In SNX/PTX animals, calcitriol + 1,34 rat PTH caused a modest increase in serum calcium (S-Ca) within the normal range. Osteoclast surface per cent was significantly lower in solvent-treated SNX/PTX rats than in sham-operated controls [3.7 +/- 2.8 osteoclast surface/bone surface (OcS/BS%) vs. 6.3 +/- 3.9], and this was not normalized by PTH + calcitriol (3.3 +/- 3). In contrast, osteoblast surface per cent and osteoid surface per cent were increased over values in sham-operated rats; as a result, co-administration of calcitriol and 1,34 rat PTH caused a highly significant increase in fractional bone volume (BV/TV). CONCLUSIONS: The results show that administration of PTH and calcitriol in doses that raise serum calcium fails to normalize the percentage of osteoclast surface, but was effective in raising osteoblast number and osteoblast volume in experimental renal failure. The results argue for abnormal response of bone cells to calcium-regulating hormones and/or the action of factors other than calcium regulatory hormones in the genesis of skeletal abnormalities of renal failure.

Animals↗
PubMed1999

Renal hemodynamic changes during smoking: effects of adrenoreceptor blockade.

BACKGROUND: Cigarette smoking accelerates progression of renal failure in diabetic and nondiabetic renal disease. Renal hemodynamics during smoking are characterised by a reversible decrease in glomerular filtration rate (GFR) and filtration fraction (FF) accompanied by increased renovascular resistance (RVR), systemic blood pressure, heart rate and plasma catecholamine concentrations. MATERIALS AND METHODS: To further assess the role of sympathetic overactivity we compared the effects of different pharmacological interventions on smoking-induced changes of renal hemodynamics in occasional smokers. In a first series, placebo pretreatment plus smoking was compared to Prazosin pretreatment (3 mg) plus smoking. In a second study, placebo pretreatment plus smoking was compared to Atenolol pretreatment (50 mg) plus smoking. RESULTS: Basal blood pressure was significantly lower with Prazosin and Atenolol. On placebo, GFR and FF decreased significantly during smoking and RVR increased. With Prazosin pretreatment compared to placebo pretreatment no statistically significant differences for the changes of GFR, FF, RPF and RVR were seen. In contrast, with Atenolol pretreatment compared to placebo pretreatment, the smoking-induced changes in active renin, GFR and RVR were significantly smaller. CONCLUSION: It is suggested that the acute renal hemodynamic effects of smoking are mediated, at least in part, via increased sympathetic activity operating mainly through beta-1 adrenergic mechanisms.

Adrenergic alpha-Antagonists↗
PubMed1999

Nephropathy in type 2 diabetes.

End-stage renal failure (ESRF) in diabetic patients, mostly type 2, has become the most frequent cause of renal replacement therapy in western Europe. The majority of patients with type 2 diabetes and renal failure suffer from diabetic glomerulosclerosis, but nondiabetic renal disease and atypical presentations, e.g. as irreversible acute renal failure or ischaemic nephropathy, play an increasingly important role. Known risk factors for the onset of diabetic nephropathy include (1) genetic predisposition (indicated by a history of hypertension and cardiovascular events in first-degree relatives), (2) quality of glycaemic control, (3) level of blood pressure, and (4) smoking. At the time when type 2 diabetes is diagnosed, an abnormal blood pressure profile is found in approximately 80%. In patients with established diabetic nephropathy, hypertension is the most important factor which promotes progression, and this is susceptible to intervention. Although less data are available for type 2 diabetes (compared with type 1 diabetes), ACE inhibitors appear to be the antihypertensive agent of first choice, but monotherapy is rarely sufficient to achieve the blood pressure goal. Although, at least in principle, diabetic nephropathy is a preventable condition, currently only a minority of type 2 diabetic patients in western Europe receives adequate medical treatment to prevent onset or progression of diabetic nephropathy. Consequently, novel approaches to patient management and interdisciplinary interaction are necessary to fulfil the postulate of the St Vincent declaration concerning prevention of diabetic complications.

Albuminuria↗
PubMed1999

Renal disease and hypertension in non-insulin-dependent diabetes mellitus.

Recent epidemiologic data demonstrate a dramatic increase in the incidence of end-stage renal disease (ESRD) in patients with non-insulin-dependent diabetes mellitus (NIDDM), thus dispelling the mistaken belief that renal prognosis is benign in NIDDM. Currently, the leading cause of ESRD in the United States, Japan, and in most industrialized Europe is NIDDM, accounting for nearly 90% of all cases of diabetes. In addition to profound economic costs, patients with NIDDM and diabetic nephropathy have a dramatically increased morbidity and premature mortality. NIDDM-related nephropathy varies widely among racial and ethnic groups, genders and lifestyles; and gender may interact with race to affect the disease progression. While the course of insulin-dependent diabetes mellitus (IDDM) progresses through well-defined stages, the natural history of NIDDM is less well characterized. NIDDM patients with coronary heart disease have a higher urinary albumin excretion rate at the time of diagnosis and follow-up. This greater risk may also be associated with hypertension and hyperlipidemia, and genes involved in blood pressure are obvious candidate genes for diabetic nephropathy. Hyperglycemia appears to be an important factor in the development of proteinuria in NIDDM, but its role and the influence of diet are not yet clear. Tobacco smoking can also be deleterious to the diabetic patient, and is also associated with disease progression. Maintaining euglycemia, stopping smoking and controlling blood pressure may prevent or slow the progression of NIDDM-related nephropathy and reduce extrarenal injury. Treatment recommendations include early screening for hyperlipidemia, appropriate exercise and a healthy diet. Cornerstones of management should also include: (1) educating the medical community and more widely disseminating data supporting the value of early treatment of microalbuminuria; (2) developing a comprehensive, multidisciplinary team approach that involves physicians, nurses, diabetes educators and behavioral therapists; and (3) intensifying research in this field.

Diabetes Mellitus, Type 2↗
PubMed1999

Endothelin receptor antagonists influence cardiovascular morphology in uremic rats.

BACKGROUND: In is generally held that renal failure results in blood pressure (BP)-independent structural changes of the myocardium and the vasculature. The contribution, if any, of endothelin (ET) to these changes has been unknown. METHODS: We morphometrically studied random samples of the left ventricle myocardium and small intramyocardial arteries in subtotally (5/6) nephrectomized (SNx) male Sprague-Dawley rats treated with either the selective ETA receptor antagonist BMS182874 (30 mg/kg/day) or the nonselective ETA/ETB receptor antagonist Ro46-2005 (30 mg/kg/day) in comparison with either sham-operated rats, untreated SNx, or SNx rats treated with the angiotensin-converting enzyme inhibitor trandolapril (0.1 mg/kg/day). RESULTS: Eight weeks later, systolic BP was lower in trandolapril-treated SNx compared with untreated SNx animals. No decrease in BP was seen following either ET receptor antagonist at the dose used. A significantly increased volume density of the myocardial interstitium was found in untreated SNx rats as compared with sham-operated controls. Such interstitial expansion was prevented by trandolapril and either ET receptor antagonist. SNx caused a substantial increase in the wall thickness of small intramyocardial arteries. The increase was prevented by trandolapril or BMS182874 treatment. The arteriolar wall:lumen ratio was significantly lower in all treated groups when compared with untreated SNx. In contrast, only trandolapril, but not the ET receptor antagonists, attenuated thickening of the aortic media in SNx animals. CONCLUSIONS: The ETA-selective and ETA/ETB-nonselective receptor antagonists appear to prevent development of myocardial fibrosis and structural changes of small intramyocardial arteries in experimental chronic renal failure. This effect is independent of systemic BP.

Animals↗
PubMed1999

Coadministration of albumin and furosemide in patients with the nephrotic syndrome.

BACKGROUND: In patients with nephrotic syndrome, the natriuretic effect of furosemide (FU) is diminished. The effect of coadministration of FU and human albumin (HA) has remained controversial. METHODS: In a double-blind, placebo-controlled study, nine nephrotic patients (six males, 48 +/- 4 years) on standardized sodium chloride intake, in random order on three separate days, received by intravenous administration for 60 minutes either (a) 60 mg FU plus a sham infusion, (b) 60 mg FU plus 200 ml of a 20% solution of HA, or (c) sham infusion plus 200 ml of a 20% solution of HA. Urinary volume, sodium, albumin and FU excretion, renal hemodynamics, and plasma atrial natriuretic factor concentration were assessed. RESULTS: Administration of FU alone significantly (P < 0.01) increased mean cumulative urinary sodium (259 +/- 30 mmol) and volume excretion (2684 +/- 167 ml) in the first eight hours as compared with the HA infusion alone (118 +/- 12 mmol, 1827 +/- 141 ml). The coadministration of FU and HA caused an even more marked increase (P < 0.01 vs. HA alone) of urinary sodium (312 +/- 28 mmol) and volume excretion (3230 +/- 201 ml); the difference to FU administration alone was significant (P < 0.05). Plasma atrial natriuretic factor, serum albumin concentration, and urinary albumin excretion increased significantly on both HA infusion days, whereas urinary excretion of FU remained unchanged with HA coadministration. Glomerular filtration rate (CIn) was not significantly affected by any of the infusion protocols, but effective renal plasma flow (CPAH) increased significantly on both HA infusion days. CONCLUSIONS: Coadministration of HA potentiates the action of FU in patients with the nephrotic syndrome, but only modestly. This effect is mediated by changes in renal hemodynamics.

Adult↗
PubMed1999

Increased frequency of G-protein beta 3-subunit 825 T allele in dialyzed patients with type 2 diabetes.

BACKGROUND: A polymorphism (C825T) in exon 10 of the gene encoding the beta 3 subunit of heterotrimeric G proteins (GN beta 3) has recently been described, and the T allele was found to be associated with late-onset hypertension. Because hypertension is a known risk factor for the development of clinically manifest progressive renal disease, we examined the C825T polymorphism in older hemodialysis patients suffering from nondiabetic renal disease or type 2 diabetes with presumed diabetic nephropathy, respectively, and in older healthy controls. METHODS: Genotyping was performed by polymerase chain reaction, followed by restriction enzyme analysis. RESULTS: The study showed that the frequency of the T allele in the nondiabetic patients on dialysis (0.232) was significantly (P < 0.03) lower than in older healthy controls (0.293). In contrast, the frequency was significantly (P < 0.02) higher in older patients with type 2 diabetes on dialysis. No significant change in T-allele frequency was noted in older patients with type 2 diabetes without microangiopathy (0.286). The odds ratios for patients with type 2 diabetes on dialysis versus nondiabetic patients on dialysis were 3.24 (1.3 to 7.9, P < 0.00079) for TT/CC and 1.82 (1.07 to 3.09, P < 0.02) for CT/CC. The respective odds ratios for patients with type 2 diabetes on dialysis versus controls were 2.05 (1.07 to 3.9, P < 0.028) for CT/CC and 1.216 (0.79 to 1.87; P < 0.37) for CT/CC. CONCLUSION: The data do not support a role of the hypertension-associated T allele in the genesis of dialysis-dependent end-stage renal failure in general, but are compatible with a specific role of the T allele in the development or progression of diabetic nephropathy.

Aged↗
PubMed1999

Edmund Randerath (1899-1961): experimental proof for the glomerular origin of proteinuria.

A century ago, Edmund Randerath (1899-1961), who was one of the pioneers in nephrology that provided indirect experimental proof for the glomerular origin of proteinuria, was born. In the first decades of this century, the concept prevailed that "nephrosis" was a process of primary tubular cell degeneration. In contrast to prevailing opinion, he interpreted these changes to be the result of the uptake and storage of serum proteins after they had been filtered in the glomerulus. Edmund Randerath proved the glomerular origin of proteinuria by astute experiments in amphibia. In the salamander, an intraperitoneal injection of albumin provoked the supposedly "degenerative" changes of tubular epithelial cells in only those nephrons that drained the coelomic cavity and were devoid of glomeruli, but not in those nephrons that were closed and attached to glomeruli. This observation provided incontrovertible evidence that the presence of serum proteins in tubular fluid was a prerequisite for the development of the tubular epithelial cell changes typically seen in nephrotic patients.

Animals↗
PubMed1999

Rationale and design of a trial improving outcome of type 2 diabetics on hemodialysis. Die Deutsche Diabetes Dialyse Studie Investigators.

BACKGROUND: Non-insulin-dependent diabetes mellitus dialysis patients have the highest cardiovascular mortality known in any group of patients. Mixed dyslipidemia with moderately elevated low-density lipoprotein (LDL) cholesterol and high levels of triglyceride-rich lipoproteins is common in this condition. It is not known, however, whether patients with type 2 diabetes on dialysis with this form of dyslipidemia derive benefit from lipid-lowering therapy. Recently, drugs have become available that potently lower triglyceride-rich, apoB-containing lipoproteins and thus permit testing of this issue. This is the first trial to address specifically the issue of whether the excessive cardiovascular mortality of patients with type 2 diabetes on dialysis can be lowered by statins. METHODS: The Die Deutsche Diabetes Dialyse Studie is a prospective randomized placebo-controlled trial that tests the hypothesis that atorvastatin, a hydroxymethyl-glutaryl coenzyme A reductase inhibitor, decreases the rate of cardiovascular mortality and of nonfatal myocardial infarction in patients with type 2 diabetes who have been on hemodialysis treatment for no more than two years. The primary endpoint, cardiovascular mortality, includes fatal myocardial infarction, sudden death, death during coronary intervention, death from heart failure, and other coronary causes. Secondary endpoints comprise overall mortality, nonfatal cardiovascular events, fatal and nonfatal cerebrovascular disease, and the mean percentage change in lipid profile from baseline. The trial enrolls 1200 men and women on hemodialysis for less than two years and with type 2 diabetes at 150 centers throughout Germany. Inclusion criteria are age of 18 to 80 years, low-density cholesterol of 80 to 190 mg/dl (2.1 to 4.9 mmol/liter), and triglyceride levels of less than 1000 mg/dl (11.4 mmol/liter). Patients are randomized to cither inactive (placebo) or active (atorvastatin, 20 mg/day) drug therapy. The average duration of follow-up is more than 2.5 years. To protect against a lower than expected rate of events, the trial will be continued until a predetermined fixed number of endpoints occurs in the entire cohort so that the predefined power of the trial will be guaranteed. CONCLUSIONS: This trial was designed to demonstrate that lipid lowering with atorvastatin will improve life expectancy and quality of life in type 2 diabetics on hemodialysis. The resolution of this question is important because the genesis of vascular lesions in this condition is multifactorial and the precise role of dyslipidemia has not been defined.

Adolescent↗
PubMed1999

Phosphate binders on iron basis: a new perspective?

Uremic patients on maintenance hemodialysis are in positive phosphate balance. This is mainly the result of the complex elimination kinetics of phosphate during dialysis. Removal of phosphate is less than net dietary intake. Classical phosphate binders such as calcium carbonate, calcium acetate, and aluminum-based compounds are limited by side effects (hypercalcemia) and outright toxicity (aluminium). There have been numerous recent attempts to develop alternative phosphate binders, e.g., polyallylamine-hydrochloride (Renagel), lanthanum carbonate, and trivalent iron-containing compounds. The latter is based on old observations that iron salts may cause hyperphosphatemia and rickets in experimental animals and in patients. This idea has recently been taken up again, and effective inhibition of net intestinal phosphate uptake in non-uremic and uremic rats has been shown using simple iron salts (citrate, chloride, ammonium citrate) and complex compounds (cross-linked dextran and stabilized polynuclear iron hydroxide). In uremic rats, the latter compound reduces urinary phosphate excretion as an indicator of reduced intestinal phosphate uptake and has also been shown to be effective in subjects with preterminal renal failure. So far, no side effects or short-term toxicity has been observed. The compound appears promising and deserves further evaluation.

Animals↗
PubMed1999

Osteodystrophy in the millennium.

Despite three decades of intensive research on the derangements of calcium phosphate metabolism of renal failure, several unresolved issues are still with us at the turn of the millennium: poor control of hyperphosphatemia, relative inefficacy of active vitamin D to prevent progressive parathyroid hyperplasia, and persistence of bone disease despite lowering of parathyroid hormone (PTH) and administration of active vitamin D. Although predictions are problematic, it is not unreasonable to hope that, barring unforeseen side effects, calcimimetics will prove to be valuable for suppressing or even preventing hyperparathyroidism, thus potentially replacing, at least in part, active vitamin D. There is also reason to hope that more effective phosphate binders with fewer side effects will become available and that controlled studies will provide a rationale for the administration of estrogens to dialyzed women. As regards understanding the pathological mechanisms, one can anticipate that the disturbances leading to autonomous growth of parathyroid cells will be elucidated and the signals involved in osteoclast/osteoblast differentiation pathways and osteoclast/osteoblast coupling will be clarified, with obvious impact on patient management.

Animals↗