[Inflammation markers in daily practice]

Cardiovascular diseases and infections remain the first mortality causes in ESRD patients. European recommendations for good clinical practice in the hemodialysis field advocate to use the inflammation markers in daily practice. These markers foretell both cardiovascular and global mortality. They also enable to detect the silent infections (parodontitis, Heliobacter pilory infection, shunt infection in PTFE), to make sure of the dialysis biocompatibility (microbiological quality of the dialysate, use of biocompatible membrane). The C-reactive protein is the most current and used marker. Its use, combined with the procalcitonin measurement, specific marker for bacterial infection, would enable the diagnostic and therapeutic strategy improvement.

[Acute changes in load: effects of myocardial velocities measured by doppler tissue imaging]

The value of measuring the velocities of myocardial motion in the analysis of regional contractility has been demonstrated. The effects of changes in load on myocardial velocities has not been extensively studied. The aim of this study was to increase the change in myocardial velocities during haemodialysis. The velocities of longitudinal myocardial motion of the posterior wall and mitral annulus were measured by Doppler tissue imaging in 33 chronic haemodialysis patients (16 men: ages 64 +/- 14 years). Using the apical 2 chamber view: systolic (S), diastolic (D) and late (A) velocities were measured before and immediately after haemodialysis. The weight loss and decrease in mean blood pressure was 2.6 +/- 1.2 Kg and 10 +/- 17% respectively. Before dialysis, the systolic and diastolic velocities were maximal at the mitral annulus and decreased from the base to the apical region of the posterior wall. After dialysis, the velocities of the basal, median and apical segments of the posterior wall increased in systole but decreased in early diastole. Conversely, diastolic velocities of the mitral annulus did not change after dialysis. The authors conclude that the systolic and diastolic velocities of myocardial motion are affected by acute changes in left ventricular load induced by haemodialysis whereas those of the mitral annulus are little affected.

The subsoil gamma-ray intensity distribution in the Oriental Region of the Republic of Paraguay

Subsoil gamma-ray intensity measurements are used in uranium prospecting and in the classification of lithologies. This work charts the subsoil gamma-ray intensity distribution in the Oriental Region of the Republic of Paraguay, a centrally located country in South America. Gamma-ray count rates were obtained at depths of 5, 10, 50, and 100 m in 158 wells and count rate contour maps were generated for each of the depths. Three regions of gamma-ray anomalies were identified.

Changes in inpatient psychiatric utilization and quality of care performance measures in a capitated HMO population, 1989-1999

Managed behavioral health care approaches have significantly reduced inpatient utilization and related cost of care, but the relationship between decreased utilization and cost of care to changes in quality of care performance over time remains in question. The trends in utilization and quality of care performance measures over the course of 10 years of the Tufts Health Plan Designated Facility Program, a model health maintenance organization capitated program for inpatient behavioral health care, are presented. The results indicate that substantial decreases in inpatient utilization were sustained while quality of care measures improved over time. The data support the Tufts Health Plan Designated Facility Program as a successful means of balancing cost containment with quality of care.

Adenocarcinoma on renal allograft as a complication at 5 years

We report a new case of renal carcinoma in allograft kidney, 5 years after transplantation, which presented as a suspect allograft abscess in a complex history of recurrent urinary infection. Only surgical management with peroperative histological evaluation permitted us to confirm the diagnosis of malignancy.

Emotional distress in critically-injured patients three months after a potentially life-threatening accident

A case-control study was carried out to determine why some critically-injured patients remained emotionally distressed while other critically-injured patients were found to be minimally distressed three months after a potentially life-threatening accidental injury. Cognitive processing and meaning theories suggest that psychological adjustment following a traumatizing event depends on the successful integration of the event into current or modified cognitive schema and the restoration of a sense of meaning in life. These cognitive processes may be facilitated by coping strategies that share concerns, mobilize support and reframe disturbing elements. The Global Severity Index was used to identify critically-injured patients as either emotionally distressed or minimally distressed. Bradburn's Psychological Well-Being Scale, Impact of Events Scale, the Meaning-of-Illness Questionnaire and Family Crisis-Oriented Personal Evaluation Scale were used to collect cross-sectional data from 51 critically-injured patients during face-to-face interviews 8-12 weeks after the accident. Twenty-seven emotionally distressed patients and 24 minimally distressed patients were compared on the variables of psychological well-being, cognitive processing efforts, restoring a sense of meaning in life and use of coping strategies. Descriptive statistics, ANOVA and MANOVA were used to test for significant differences between the two groups. The findings showed that emotionally distressed patients scored significantly higher on efforts to cognitively process what happened, share concerns and mobilize support. They also had difficulty acknowledging the negative effects of the accident on the self and a poorer sense of psychological well-being. In contrast, minimally distressed patients evidenced a significantly greater ability to acknowledge the negative effects on the self and a higher level of psychological well-being. The potential differences between the two groups in the magnitude of the relationships of meaning, cognitive processing and coping strategies on psychological well-being were assessed by hierarchical regression equations. Psychological well-being of minimally distressed patients was characterized by a significantly higher perception of their capabilities and strengths and by an ability to acknowledge a change in their relations with family and friends.

Learning to listen: serendipitous outcomes of a research training experience

Experience gained in a qualitative research-training project led a group of clinical nurse specialists to discover the value of using research interview strategies in their clinical work. Clinical interviews, designed to garner data sufficient to decide on interventions, narrow the focus of the interviewer to information deemed relevant to that end. Research interview strategies involve a temporary suspension of the search for intervention, encourage a full description of the respondent's story and experience, and emphasise really listening to that story. In this case it is the respondent who decides what the story is and what information is relevant. This leads the interviewer to a fuller understanding of the context and perceptions of the respondent. The understanding and knowledge thus obtained comprise a better foundation for devising interventions which are individualised and specific to the individual and family.

[Coronary involvement in systemic lupus erythematosus]

BACKGROUND

Coronary artery disease is an uncommon event in lupus erythematosus. The mechanisms responsible for coronary occlusion are probably complex and intermixed. We report three patients with lupus erythematosus and antiphospholipid antibodies who had coronary artery disease diagnosed with coronary angiogram.

OBSERVATION

Coronary artery disease occurred in three young patients aged from 21 to 35 years 3 to 11 years after the onset of lupus. They all had antiphospholipid antibodies. They had been treated with corticosteroids for 6 to 36 months. Two of them were smokers. Angiograms showed coronary occlusion two patients while the third one had probable myocardial microvasculopathy. The lupus was quiescent in all cases when coronary artery disease occurred.

DISCUSSION

Antiphospholipid antibodies associated with smoking may be involved in the pathogenesis of coronary artery disease in these 3 patients.

[Massive poisoning by African bee stings]

BACKGROUND

Bee stings can cause severe toxic effects when envenomation is massive.

CASE REPORT

While touring in Casamance (Southern Senegal) a white male was severely stung by a swarm of African bees. The massive envenomation caused rhabdomyolysis, hemolysis and acute renal failure. Pathology examination of kidney and bladder specimens showed vasculitis affecting both arteries and veins. The patient was treated with several hemodialysis sessions and renal function returned to normal three months after the incident.

DISCUSSION

Bees in Africa, known as "killer bees", are particularly aggressive. They have recently been imported from tropical zones in America where a large number of deaths have been reported. Most cases of massive envenomation have shown acute tubular necrosis or renal involvement with myoglobinuria or hemoglobinuria. The renal pathology observed in our case is not usually described.

[Extracapillary glomerulonephritis secondary to D-penicillamine. Apropos of 1 case and review of the literature]

Extracapillary glomerulonephritis was diagnosed in a 51-year-old woman after 11 months of D-Penicillamine treatment given for systemic sclerosis. Antineutrophil cytoplasmic antibodies specific for myeloperoxydase were detected. Penicillamine was stopped and the patient was treated with plasma exchanges, cyclophosphamide and corticosteroids. The renal function progressively deteriorated leading to end stage requiring dialysis. Previous reports of extracapillary glomerulonephritis after D-penicillamine are analysed. Several cases with alveolar haemorrhage are consistent with the diagnosis of microscopic polyangiitis.

Altered flow-dependent vasodilatation of conduit arteries in maintenance haemodialysis

BACKGROUND

An altered arterial nitric oxide (NO) pathway could partly explain the damage to arteries observed in haemodialyzed (HD) patients. The present study was designed to non-invasively evaluate the NO pathway of peripheral conduit arteries in HD patients.

METHODS

Twelve normotensive, non-diabetic HD patients treated with erythropoietin and 12 matched healthy controls (C) were included in the study. The effect of endogenous release of NO was assessed by measuring the flow-dependent vasodilatation of the radial artery (post-ischaemic hyperaemia), and the response to exogenous NO assessed using sublingual glyceryl trinitrate administration (GTN).

RESULTS

Radial artery diameter (echo-tracking), radial blood flow (RBF: Doppler) and mean arterial pressure (Finapres) were identical at baseline in HD patients and in healthy subjects. The flow-dependent vasodilatation of the radial artery was decreased in HD patients (C: 9 +/- 1% vs HD: 3 +/- 05%, P < 0.05). The decrease in radial vascular resistance (C: -44 +/- 4% vs HD: -24 +/- 2%, P < 0.05) and the increase in radial diameter (C: 31 +/- 2% vs HD: 25 +/- 2%, P < 0.05) after GTN administration were less in HD patients than in controls. The ratio between the increase in diameter after hyperaemia to the increase in diameter after GTN, was also diminished in HD patients (C: 30 +/- 3% vs HD: 13 +/- 2%, P < 0.001).

CONCLUSIONS

The flow-dependent vasodilatation of peripheral conduit arteries is altered in HD patients and is associated with a slight but significant decrease in the vasodilating response to exogenous NO. These results suggest, in the absence of changes in basal radial vascular resistance and arterial diameter, more a decrease in endothelial NO bioavailability, than an increase in basal vascular tone.

Effect of the serotonin 5-HT4 receptor agonist cisapride on aldosterone secretion in corticotropic insufficiency and primary hyperaldosteronism

Serotonin (5-HT) stimulates aldosterone secretion in man through activation of 5-HT4 receptors coupled to adenylyl cyclase via a Gs regulatory protein. In adrenocortical cells, the levels of expression of the Gs protein and ACTH receptor are decreased when the cells are deprived of ACTH and angiotensin II (ANG II). In order to examine the possible influence of ACTH and ANG II on the responsiveness of human glomerulosa cells to 5-HT, we have investigated the effect of cisapride, a 5-HT4 receptor agonist, on plasma aldosterone in patients with suppressed plasma ACTH, i.e. patients with corticotropic insufficiency (CI), and in patients with suppressed renin-ANG II activity, i.e. patients with primary hyperaldosteronism (PH) including both aldosterone-producing adenoma and idiopathic hyperaldosteronism. After 2 h of recumbency, all patients received a single oral dose of 10 mg cisapride. In the CI group, cisapride induced a 5-fold increase in plasma aldosterone levels without any modification of plasma renin, potassium or cortisol levels. Combined administration of cisapride and ACTH caused an increase in plasma aldosterone similar to that produced by ACTH alone. In the PH group, cisapride was still able to cause a 3.6-fold increase in plasma aldosterone levels while renin remained suppressed throughout the study. Taken together, these data show that cisapride stimulates aldosterone secretion in CI and PH patients, indicating that prolonged suppression of plasma ACTH or renin-ANG II activity does not affect the sensitivity of glomerulosa cells to 5-HT. The present study also demonstrates that the stimulatory effects of 5-HT and ACTH on aldosterone secretion are not additive.

[Interstitial nephropathies of toxic or drug origin. New causes, new prospects]

PHENOTYPING INTERSTITIAL INFILTRATIONS: Recent progress has led to the distinction between type I and type II fibroblasts in the renal interstitium. The cellular phenotype of pathological infiltrations can be identified with monoclonal antibodies. DRUG-INDUCED INTERSTITIAL NEPHROPATHIES: Extrarenal manifestations (skin eruptions, fever, joint pain) often suggests the diagnosis but may be absent, in which case renal histology is required. CAUSAL DRUGS: Among the different causal agents, nonsteroid anti-inflammatory drugs cause abnormal leakage from glomerular capillaries favoring the development of a nephrotic syndrome associated with renal failure and major cell infiltration into the interstitial tissue. CHRONIC DISEASE: Chronic interstitial nephropathy is nearly asymptomatic and may only be discovered at an advanced stage. Briefly, there are three categories which result from long-term administration of 5-aminosalicylate, use of Chinese herbal medicines to lose weight, and chronic intoxication with ochratoxin (a mycotoxin). COMPLEX PHYSIOPATHOLOGY: Immunological mechanisms are involved although it is not always easy to distinguish between manifestations of humoral and cellular reactions. Both could be implicated as indicated in recent experimental animal models which throw more light on the pathological process in humans. RENAL PROGNOSIS: Different strategies can be used to halt or limit the development of fibrosis and thus improve prognosis of toxic interstitial nephropathies: counteract cellular immunity reactions, inhibit fibroblast proliferation and activation, reduce synthesis and stimulate degradation of the extracellular matrix, and inhibit collagen formation.

Crescentic glomerulonephritis in juvenile chronic arthritis

Juvenile chronic arthritis (JCA) was diagnosed in 2 young girls. In one of them, antinuclear antibodies (ANA) were strongly positive during the course of erosive polyarthritis. After 5 years followup, severe renal insufficiency occurred. Antineutrophil cytoplasmic antibodies (ANCA) were positive with a perinuclear pattern on indirect immunofluorescence (IIF) and antimyeloperoxidase (MPO) specificity. Renal biopsy showed severe crescentic glomerulonephritis without significant deposits on IIF. Treatment consisted of prednisone and monthly intravenous cyclophosphamide pulse. Renal failure worsened and hemodialysis was necessary. A 2nd patient was referred for polyarthritis with positive rheumatoid factors without positive ANA. The presence of microscopic hematuria led to the discovery of crescentic glomerulonephritis with positive ANCA of anti-MPO specificity. At latest examination, after prednisone for 10 months and azathioprine for 6 months, the patient had moderate proteinuria with normal renal function. These observations emphasize that in juvenile onset chronic polyarthritis, renal microscopic angiitis with ANCA of anti-MPO specificity may occur.

Pharmacokinetics of netivudine, a potent anti-varicella zoster virus drug, in patients with renal impairment

The pharmacokinetics of a single oral 200 mg dose of netivudine (1-(beta-D-arabinofuranosyl)-5-(1-propynyl)uracil), a nucleoside analogue under development for use in varicella zoster virus infections, were studied in 12 renal failure (RF) subjects (creatinine clearance 15 +/- 7 mL/min) and 12 age-matched healthy subjects with normal creatinine clearance. Blood and urine samples were collected up to nine days after drug administration. Concentrations of netivudine and of its main metabolite, the pyrimidine base 5-(1-propynyl)uracil (5 PU), were determined by a specific high performance liquid chromatography assay. The mean peak plasma concentrations of netivudine, Tmax, and volume of distribution were not significantly affected by RF. The elimination half-life of netivudine was approximately 15 h in subjects with normal renal function and 60 h in RF patients. Plasma and renal clearances of netivudine were significantly reduced in RF patients and AUC was three to four times higher in these patients. Cmax and AUC of 5 PU were higher in RF patients, and the half-life was also significantly longer. However, the half-life of this metabolite was much lower than that of the parent compound. Tmax and the lag time were similar in the two groups. There were highly significant correlations for netivudine and 5 PU between half-life and creatinine clearance and between renal clearance and creatinine clearance. These findings suggest that netivudine dosage may need to be reduced in patients with severe renal failure, and confirm that formation of the 5 PU is independent of the elimination of netivudine from plasma.

Kinetics, safety, and efficacy of ramipril after long-term administration in hemodialyzed patients

We studied the efficacy and safety of ramipril and the kinetics of its active moiety ramiprilat in 12 hypertensive patients receiving regular hemodialysis, after a single dose and after long-term (28 days) administration. Patients received 2.5 mg ramipril after each hemodialysis. On days 1 and 29, ramipril was administered 4 h before the hemodialysis and serial blood samples were obtained for 9 h for determination of pharmacokinetic parameters. Tolerability was good, and all patients completed the study. There was a high degree of angiotensin-converting enzyme (ACE) inhibition throughout the study. Ramipril had a clear-cut antihypertensive effect. Long-term administration of ramipril did not modify the time to peak ramiprilat concentration, but increased the mean maximal concentration significantly: 20.2 +/- 12.7 vs. 10.4 +/- 7.1 ng center dot ml-1. The mean accumulation ratio was 2.2. Ramiprilat hemodialysis clearance was 31.7 ml/min (range 4.2-64.9 ml/min) on day 1 and 21.0 ml/min (range 7.9-56.5 ml/min) on day 29. Ramipril 2.5 mg, administered after hemodialysis, appears to be safe and effective in hypertensive patients receiving periodic hemodialysis. Despite an increase in ramiprilat concentration from day 1 to day 29, the steady state was reached. We describe the role of nonrenal clearance of ramiprilat.

[Course of ischemic risk in treated atheromatous hypertensive patients. The PRIHAM study (Prognosis of Ischemic Risk in Atheromatous Patients under Mediatensyl)]

Hypertension is one of the major cardiovascular risk factors. However it seldom occurs alone in a patient and the antihypertensive treatment should be taken into account when assessing global cardiovascular status. The PRIHAM study was an open study which enrolled 3,216 hypertensive atheromatous patients who already has had a clinical ischaemic accident. Patients were followed-up for 3 years. The lowering effect on cardiovascular risk, starting from the fifteenth month was confirmed to the end of 36-month study. The effect on blood pressure was observed from the third month. Stabilized blood pressure observed within the first year persisted throughout the three years without tachyphylaxis. It was effective on SBP (-14.4%) and on DBP (-15%) while maintaining a stable heart rate both in the supine position or immediately upon standing or after 3 minutes in the standing position. Tolerance was globally judged as good or very good by the investigating practitioners and the patients expressed an improvement in their feeling of well-being. In conclusion, from the level of effectiveness obtained and the low incidence of adverse effects, urapidil appears well adapted and easy to manage in a population with a particularly high cardiovascular risk.

[Functional acute kidney failure]

Prerenal acute renal failure is defined as a reduction in the glomerular filtration rate due to a primary disturbance in renal hemodynamics in the absence of any structural kidney damage. In case of moderate hypotension or hypovolemia, a number of adaptative systemic and intrarenal responses preserve renal perfusion and filtration rates, particularly by inducing a marked reduction in preglomerular arteriolar resistance and an increase in postglomerular resistance. However, these mechanisms are inherently limited. In the presence of advanced circulatory failure or iatrogenic pharmacologic interventions compromising these renal defense mechanisms, prerenal failure becomes evident. Therefore, prerenal failure may occur during acute hemodynamic disturbances due to hypovolemia or systemic vasodilatation, in severe cardiac failure, in cirrhosis with ascites, and in certain clinical situations following administration of nonsteroidal antiinflammatory agents or angiotensin converting enzyme inhibitors. The treatment depends on the underlying cause.

Renal hemodynamics and sodium excretion after acute and chronic administration of cicletanine in normotensive and hypertensive subjects

We examined the effects of two therapeutic oral (p.o.) doses of cicletanine (50 and 100 mg daily) on renal hemodynamics and segmental tubular handling of sodium. Six normotensive (NT) healthy subjects (group 1) received 50 mg cicletanine, and 12 moderately hypertensive (HT) patients with normal sodium diet and randomly divided into two groups of 6 were treated either with cicletanine 50 mg (group II) or with cicletanine 100 mg (group III). Studies were performed both acutely and after 4 weeks of cicletanine administration. After 28-day treatment, blood pressure (BP) was significantly reduced in HT patients. In NT subjects (group I) and HT patients (groups II and III), acute administration of cicletanine 50 or 100 mg at day 0 did not significantly modify glomerular filtration rate (GFR) or renal blood flow (RBF), but markedly increased fractional excretion of Na (FENa) by 67% in group I and by 62 and 135% in groups II and III, respectively. Fractional distal reabsorption of Na (FDRNa) was significantly reduced in the three groups after cicletanine administration. After 4-weeks treatment, GFR and RBF were not significantly modified. The increase in FeNa and decrease in FDRNa were of the same magnitude as that at day 0. No major changes occurred in hormonal profile [renin, aldosterone, atrial natriuretic factor (ANF)]. Even at low doses, cicletanine has a natriuretic effect in NT and HT subjects. Unchanged fractional reabsorption of lithium and a significant decrease in FDRNa in the three groups suggest that this natriuretic effect occurs at the distal tubule.

Influence of sympathetic tone on mechanical properties of muscular arteries in humans

Although smooth muscle tone is a key determinant of mechanical properties of arteries in animal experiments, it has not yet been studied in humans because of technical limitations. To assess the influence of tone on arterial properties in humans and to emphasize the interest of calculation at specific stress, we used echo tracking and photoplethysmographic measurement of arterial pressure to study radial arterial mechanics during a cold pressor test (CPT) in 12 healthy volunteers (28 +/- 2 yr). During CPT, mean arterial pressure rose from 83 +/- 3 to 106 +/- 5 mmHg (P < 0.05), internal diameter decreased from 2.75 +/- 0.15 to 2.54 +/- 0.14 mm (P < 0.05), and wall thickness increased from 0.576 +/- 0.027 to 0.634 +/- 0.029 mm (P < 0.05). At a specific pressure (105 mmHg), midwall stress and incremental modulus decreased whereas arterial compliance increased. The incremental modulus of elasticity and compliance were fitted as functions of pressure and of midwall stress. CPT decreased the modulus about equally at all wall stresses measured. The modulus decreased and the compliance increased at every level of pressure measured. At all levels of midwall stress, the compliance was decreased. Thus acute sympathetic stimulation induced by CPT decreases the wall stiffness of human arteries in vivo. This may be explained by an unloading of stiffer wall components during active arterial constriction.

[Course of ischemic risk in treated atheromatous hypertensive patients. The PRIHAM study]

Hypertension is one of the major cardiovascular risk factors. However seldom occurs alone in a patient and the antihypertensive treatment should be taken into account when assessing global cardiovascular status. The PRIHAM study was an open study which enrolled 3,216 hypertensive atheromatous patients who already has had a clinical ischaemic accident. Patients were followed-up for 3 years. The lowering effect on cardiovascular risk, starting from the fifteenth month was confirmed to the end of 36-month study. The effect on blood pressure was observed from the third month. Stabilized blood pressure observed within the first year persisted throughout the three years without tachyphylaxis. It was effective on SBP (-14.4%) and on DBP (-15%) while maintaining a stable heart rate both in the supine position or immediately upon standing or after 3 minutes in the standing position. Amongst diabetic and dyslipidemic patients, an absence of deleterious metabolic effects was noticed, parallel with the effectiveness. Tolerance was globally judged as good or very good by the investigating practitioners and the patients expressed an improvement in their feeling of well-being. In conclusion, from the level of effectiveness obtained and the low incidence of adverse effects, urapidil appears well adapted and easy to manage in a population with a particularly high cardiovascular risk.

Randomised controlled trial of enalapril and beta blockers in non-diabetic chronic renal failure

OBJECTIVE

To compare the ability of angiotensin converting enzyme inhibitors and beta blockers to slow the development of end stage renal failure in non-diabetic patients with chronic renal failure.

DESIGN

Open randomised multicentre trial with three year follow up.

SETTING

Outpatient departments of six French hospitals.

PATIENTS

100 hypertensive patients with chronic renal failure (initial serum creatinine 200-400 mumol/l. 52 randomised to enalapril and 48 to beta blockers (conventional treatment).

INTERVENTIONS

Enalapril or beta blocker was combined with frusemide and, if necessary, a calcium blocker or centrally acting drug in patients whose diastolic pressure remained above 90 mm Hg.

RESULTS

17 patients receiving conventional treatment and 10 receiving enalapril developed end stage renal failure. The cumulative renal survival rate was significantly better in the enalapril group than in the conventional group (P < 0.05). The slope of the reciprocal serum creatinine concentration was steeper in the conventionally treated patients (-6.89 x 10(-5)l/mumol/month) than in the enalapril group (-4.17 x 10(-5)l/mumol/month; P < 0.05). No difference in blood pressure was found between groups.

CONCLUSION

In hypertensive patients with chronic renal failure enalapril slows progression towards end stage renal failure compared with beta blockers. This effect was probably not mediated through controlling blood pressure.

A perspective on di-2-ethyl-hexyphthalate in intravenous therapy

Di-2-ethyl-hexyphthalate (DEHP) is a major component of polyvinyl chloride (PVC), which is the plastic of choice used to fabricate disposable medical devices. Most containers and tubings used to administer intravenous therapy are made with PVC, and DEHP controls the strength and pliability of these PVC products. Certain infusates have been shown to leach DEHP from plastic. The possibility of harmful effects to the human body is a concern, especially to infants and pregnant females. Carcinogenicity, hepatotoxicity, teratogenicity, and more recently, cardiotoxic effects have been documented, yet we continue to use these products that leach DEHP when alternatives are available. Exposure to this substance can be minimized with careful adherence to manufacturers' recommendations when administering substances that leach DEHP.

[Mechanical adaptation of muscular arteries to acute increase of blood pressure in man. Contribution of the measurement of arterial wall thickness]

Although it was usually admitted that hypertension is associated with a reduction in conduit artery compliance and distensibility, recent experiments using newly developed high precision echo-tracking devices allowing simultaneous, non-invasive measurements of blood pressure and arterial diameter have suggested that compliance and distensibility, when calculated at equal transmural pressure, could indeed be maintained, or even increased, in hypertensive subjects. Such a maintained arterial compliance could be explained best by a decrease in wall stress despite the increase in arterial blood pressure, through either an increase in wall thickness or a decrease in arterial wall elastic modulus. Thus, the goal of the present study was to assess the role of the changes in these determinants of vessel compliance in the arterial response to an acute increase in arterial pressure in 7 healthy volunteers. Arterial pressure (AP, Finapress) as well as right radial artery internal diameter and wall thickness (Echo-Tracking, NIUS 2, Asulab) were measured continuously before and after a 2 min cold pressor test (CPT). The following parameters were then calculated at fixed (105 mmHg) pressure from the pressure/diameter curve: compliance (mm2/mmHg) and distensibility (mmHg-1) mid-wall stress (dynes/cm2) and incremental elastic modulus (dynes/cm2). During CPT, mean AP increased (from 83 +/- 4 to 106 +/- 8 mmHg; p < 0.01), compliance distensibility; and mean internal diameter (mm) decreased, mean wall thickness (mm) increased, whereas wall stress and elastic modulus remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies to Sm, RNP and SSB detected by solid-phase ELISAs using recombinant antigens: a comparison study with counter immunoelectrophoresis and immunoblotting

Sera from 64 patients with systemic lupus erythematosus (SLE) were tested for the presence of anti-Sm, anti-RNP, and anti-SSB antibodies using commercially available solid-phase enzyme-linked immunosorbent assays (ELISAs) and recombinant nuclear proteins as substrates. The results were compared to those obtained with counterimmunoelectrophoresis (CIE) and immunoblotting (IBT) using a rabbit thymus extract (RTE) as the substrate. The ELISAs detected antibodies to Sm, RNP, and SSB in, respectively, 25%, 36%, and 15% of the SLE sera. Neither IBT-positive/ELISA-negative nor CIE-positive/ELISA-negative sera were found, regardless of the specificity considered, suggesting that ELISAs using recombinant nuclear antigens are highly sensitive. Discrepancies were observed between the results obtained with these different techniques. In addition to sera positive by both IBT and ELISA but negative by CIE, a substantial number of sera had ELISA-detectable anti-Sm, anti-RNP, and anti-SSB antibodies which failed to react with the corresponding polypeptides by IBT. The reasons for ELISA/IBT discrepancies were explored; however, no single explanation was found. Instead, a higher sensitivity of the ELISA to detect antibodies directed against certain polypeptides, the possible inability of IBT using RTE as the substrate to detect antibodies reacting with conformational antigenic determinants, and false-positive reactions in the ELISAs were suggested. Thus, it is still advisable to perform both IBT and ELISAs simultaneously in well-defined autoimmune diseases to further analyze the potential advantages of ELISAs using recombinant antigens.

[Renal aging in man]

Renal morphological and functional changes occur in the elderly. Between the ages of 50 and 80 years the renal mass diminishes by a mean of 20 percent, to the expense of the renal cortex. Glomerular sclerosis results in a gradual fall in the number of functioning glomeruli. Simultaneously, a decrease of about 7 percent in glomerular filtration rate per decade after the age of 40 years and a 10 percent decrease in renal plasma flow per decade, and therefore an increase in filtration fraction, are observed. These haemodynamic abnormalities are accompanied by changes in tubular function, including a delay in renal adjustment to sodium overload, and above all to sodium restriction, together with a decrease in concentrating and, to a lesser extent, diluting capacity. In actual fact, the intensity of glomerular sclerosis varies considerably from one subject to another, and the decrease in glomerular filtration rate is far from being constant. These changes are perhaps not ineluctably associated with aging; they might result from pathological processes that have gone unnoticed.

A low molecular weight heparin decreases plasma aldosterone in patients with primary hyperaldosteronism

Four patients with primary hyperaldosteronism were treated with nadroparin 4100 or 6150 antiXa IU daily for 4 days. Plasma and urine sodium and potassium, and plasma aldosterone and renin were monitored before, during and after the study. After four days of treatment, and for the following two days, plasma aldosterone was decreased (by a mean of 49% on Day 6), and urinary Na/K was increased (3.7-fold). The direction of the changes was reversed on Day 8. The study has confirmed the effect of low molecular weight heparin on aldosterone, and makes it unlikely that it is related to inhibition of angiotensin II stimulation in these patients, as renin could not be detected in their plasma.