Contrast medium in power Doppler ultrasound for assessment of synovial vascularity: comparison with arthroscopy

OBJECTIVE

To evaluate the reliability of contrast-unenhanced power Doppler (CUPD) and contrast-enhanced power Doppler (CEPD) ultrasound (US) assessment of synovial vascularity of knee joint synovitis by prospective comparison with the "gold standard," arthroscopy.

METHODS

A total of 18 knees of 17 patients with refractory rheumatoid and psoriatic knee joint synovitis were examined by US. Recognition of PD synovial vessel flow and its spatial arrangement in relation to the pannus/cartilage interface (P/CI) or fluid/synovium interface (F/SI) were studied by CUPD- and CEPD-US after a single intravenous bolus of galactosel palmitic acid (Levovist). Arthroscopy video recordings were reanalyzed by computer image analysis to assess synovial vascular marking. CUPD and CEPD flow signal scores were compared with each other and with corresponding vascular marking scores. Using villous vascular marking as reference, CUPD and CEPD sensitivity and specificity were measured. Interobserver variability was evaluated.

RESULTS

Compared with the unenhanced PD method, contrast administration increased the PD flow signal score in 13/18 knees (72.2%), allowing increased detection of F/SI PD flow signal configuration (p < 0.018) and of the coexistence of P/CI and F/SI PD imaging (p < 0.0078). With arthroscopy as reference, contrast-enhanced PD was found to be more useful than the unenhanced method, showing more reproducible PD signal scores (p = 0.05 vs p = nonsignificant), as well as higher sensitivity (80% vs 30%), but lower specificity (62% vs 87%), in the recognition of increased vascularity of synovial villi. Interobserver agreement was 100%.

CONCLUSION

The prospective comparison with arthroscopy showed the reliability of the CEPD method in synovial vessel recognition and its potential clinical usefulness in assessment of knee joint synovitis.

Body composition measurements: interpretation finally made easy for clinical use

PURPOSE OF REVIEW

This review presents the latest clinical applications of bioelectrical impedance analysis. It discusses the evaluation of nutritional status by using fat-free mass and body fat, percentiles of fat-free mass and body fat, height-normalized fat-free mass and body fat mass indices and a resistance/reactance vector graph.

RECENT FINDINGS

Fat-free mass and body fat can be used to evaluate nutritional status by comparing individuals or groups of individuals with themselves or with reference values. Percentile distributions are also useful in determining whether individuals or groups fall within the population range. Percentile ranks can also be used to define nutritional depletion and obesity. The use of the fat-free mass and body fat mass indices has the advantage of compensating for differences in body height. The use of low, normal, high and very high fat-free mass and body fat mass indices ranges that correspond to underweight, normal, overweight and obese body mass index categories further aid in the nutritional assessment process. With vector bioelectrical impedance analysis, an individual impedance vector is compared with the 50, 75, and 95% tolerance ellipses calculated in the reference, healthy population, allowing evaluation in any clinical condition. More accurate estimates of conventional bioelectrical impedance analysis equations might be obtained in individuals with a normal impedance vector.

SUMMARY

The assessment of fat-free mass and body fat provides valuable information about changes in body composition with weight gain or loss and physical activity, and during ageing. The use of percentiles and height-normalized fat-free mass and body fat permit the classification of patients as under or overnourished.

Bioimpedance vector pattern in cancer patients without disease versus locally advanced or disseminated disease

OBJECTIVE

Bioelectrical impedance vector analysis allows non-invasive evaluation of soft tissue hydration and mass through pattern analysis of vector plots as height, normalized resistance, and reactance measurements.

METHODS

Whole-body impedance measurements were made with a single frequency (50 kHz) analyzer (BIA-101, Akern/RJL Systems) in 148 adult, white, male subjects 45 to 85 y old: 56 healthy control subjects, 31 cancer patients after surgical procedure (without disease), and 61 patients with locally advanced (30 patients) or disseminated (31 patients) disease with the same body mass index and age. All patients were free from antineoplastic treatment and active nutritional intervention.

RESULTS

Mean vectors of cancer groups without disease and locally advance disease versus the control group were characterized by a comparable normalized resistance component with a reduced reactance component (separate 95% confidence limits, P < 0.05), indicating a comparable ionic conduction (hydration) with loss of dielectric mass (cell membranes and tissue interfaces) of soft tissues. Overlapping 95% confidence limits of their mean vectors indicated comparable electrical tissue properties in less versus more advanced disease.

CONCLUSION

Monitoring vector displacement trajectory toward the reference target vector position may represent useful feedback in support therapy planning of individual patients.

Effect of epoetin on HO-1 mRNA level and plasma antioxidants in hemodialysis patients

OBJECTIVE

Patients with renal failure and undergoing hemo- (HD) or peritoneal dialysis are under oxidative stress which is thought to contribute to the long-term complications noted in this patient population. One effect of HD-induced oxidative stress is via red blood cell (RBC) membrane lipid peroxidation leading to RBC destruction and anemia. Interaction of this oxidative stress with epoetin (EPO) treatment to increase RBC number and Hb concentration remains unexplored.

PATIENTS AND METHODS

This preliminary study used RT-PCR as well as colorimetric based assay approaches to evaluate the effect of EPO-alpha treatment on markers of oxidative stress in hemodialysis patients. Eighteen patients (12 males, 6 females, age range 45 - 68), were treated with EPO-alpha (Eprex) 50 UI/kg thrice weekly over an 8-month study period. Monocytes were isolated at baseline, then monthly thereafter, monocyte heme-oxygenase-1 (HO-1) and plasma Hb and antioxidant power (AOP) were determined.

RESULTS AND CONCLUSIONS

Treatment with EPO increased Hb (9.4 +/- 0.7 g/dl to 10.9 +/- 0.5, mean +/- SD p < 0.001). In addition, both monocyte HO-1 mRNA (0.34 +/- 0.08 vs. 0.59 +/- 0.02 d.u. p < 0.001) and plasma AOP (1,379.8 +/- 175 micromol/l to 1,624 +/- 170, p < 0.04) increased. While AOP changes showed no correlation with other indices, increases in HO-1 and Hb were positively correlated using 2 different measures: delta Hb (peak Hb - baseline Hb) vs. delta HO-1 (peak HO-1 mRNA - baseline HO-1 mRNA) as well as delta Hb(5 months-baseline) vs. delta HO-1 (5 months - baseline) mRNA (r = 0.81, p < 0.001 and r = 0.76, p < 0.001; respectively). In conclusion, the increases upon EPO treatment of both HO-1 gene expression and plasma AOP as well as the significant correlation between delta Hb and delta HO-1 mRNA suggest that EPO treatment reduces oxidative stress via a combination of effects. These could potentially include effects on oxidative stress directly as well as effects on the levels and types of antioxidants present in plasma.

Subcutaneous epoetin-alpha every one, two, and three weeks in renal anemia

BACKGROUND

The same epoetin dose administered subcutaneously (SC) once weekly instead of thrice or twice weekly to patients with renal anemia is reported to be equally effective. The aim of this study was to verify whether a target hemoglobin (Hb) could be maintained with SC epoetin administered at longer intervals - every one, two or three weeks.

METHODS

This was a single-center, retrospective cohort study on 67 consecutive outpatients (35 adult caucasian males) with anemia secondary to chronic renal insufficiency, all in follow-up for at least 12 months, who maintained the target Hb of 11 to 13 g/dL for six months with one SC injection of 10,000 U epoetin-alpha every five days (14,000 U/wk), or every one (Epo/1, 10,000 U/wk), two (Epo/2, 5,000 U/wk) or three weeks (Epo/3, 3,333 U/wk) according to their Hb concentrations after the induction phase.

RESULTS

The target Hb > or = 11 g/dL was maintained over six months of treatment with SC epoetin > 10,000 U/week in 4 patients (6.0%, 95% CI 1.5-14.6) and with SC epoetin < or = 10,000 U/week in 63 patients (94.0%, 95% CI 85.4-98.4). Among the latter, 16 (25.4 %, 95% CI 15.3-37.9) maintained the target with Epo/1, 25 (39.7 %, 95% CI 27.6 to 52.8) with Epo/2, and 22 (34.9 %, 95% CI 23.3 to 48.0) with the Epo/3 regimen. On average, they received 5,688 U/week (86.2 U/kg/week) and the expected number of injections was 30 per year.

CONCLUSIONS

Epoetin 10,000 U SC every two or three weeks maintained the target Hb concentration of 11-13 g/dL over a six month period in 75% of patients. Prospective, randomized and controlled trials are needed to establish the validity of this simplified regimen.

Pulse pressure and coronary mortality in elderly men and women from general population

The aim of this work was to evaluate whether pulse pressure (PP) in elderly people is a better predictor of coronary mortality than systolic and diastolic blood pressure taken alone. For this aim, 3282 elderly subjects aged >or=65 years were studied in a population-based frame. Blood pressure was repeatedly measured and averaged; historical data, anthropometrics, blood tests and 14-year coronary mortality were recorded. Statistics included analysis of covariance, Cox analysis and bivariate vectorial analysis. Coronary mortality in women was predicted by PP (1.01 excess risk/mm Hg PP) and was significantly higher in the 3rd than in the 1st tertile of PP (relative risk 2.90); neither systolic nor diastolic pressure taken alone influenced mortality. When systolic and diastolic pressures were both entered into a Cox model, the former had a positive and the latter a negative effect on survival, confirming a prognostic role of PP. For any given level of systolic pressure, mortality was inversely associated with diastolic pressure. Finally, the mean vector representing both systolic and diastolic pressures of non-surviving women was characterised by higher systolic and lower diastolic components than in non-surviving. No significant trend of mortality in relation to either systolic blood pressure or PP was observed in men. In conclusion, the combination of systolic and diastolic pressure called PP is an independent predictor of coronary mortality in elderly females, and a better predictor than systolic or diastolic pressure alone.

[Latent celiac disease in subjects with serum anti-endomysial antibodies and normal intestinal biopsy]

OBJECTIVES

Data on the follow-up of a group of subjects with serum antiendomysial antibodies (EMA) and normal mucosal architecture at the intestinal biopsy are reported. Clinical problems concerning possible evolution of potential celiac disease (CD) towards gluten-induced histological damage are discussed.

METHODS

Eleven patients belonging to high-risk groups for CD (5 with type-1 diabetes, 2 with familiarity for CD and 4 with symptoms suggesting CD) who had a normal intestinal biopsy, despite positive antiendomysial test, were followed-up. Antigliadin and antitransglutaminase antibodies (anti-tTG) and HLA genotyping were also assessed. According to clinical and serological data a second biopsy was performed in six of them.

RESULTS

At the time of the first normal biopsy, all patients were positive for EMA and 5/8 for anti-tTG. Five of 6 subjects genotyped were HLA-DQ2+ or DQ8+. Six patients were rebiopsed after 1 to 4 years. Three had mucosal atrophy, 1 had mild increase of intraepithelial lymphocytes and 2 were morphologically normal.

CONCLUSIONS

Subjects with antiendomysial antibodies and normal intestinal biopsy deserve clinical and serological follow-up to reduce the time of possible latency of CD. Although good predictors of progression of the disease are not still available, antiendomysial antibodies assessment and HLA genotyping may help to suggest individuals at higher risk to develop gluten-induced enteropathy. This study confirms that subjects with persistent signs of gluten sensitivity and normal biopsy should be re-examined.

Reference values of the bioelectrical impedance vector in neonates in the first week after birth

OBJECTIVE

To determine the reference, bivariate, tolerance intervals of the whole-body impedance vector for healthy white neonates, we performed an observational, cross-sectional study in two university hospitals.

METHODS

The impedance vector (standard, tetrapolar analysis at 50-kHz frequency) was measured in 163 consecutive subjects (87 boys and 76 girls) with postnatal ages of 1 to 7 d. Bivariate vector analysis was conducted with the resistance-reactance (RXc) graph method.

RESULTS

The age-specific 95% confidence intervals of mean vectors and the 95%, 75%, and 50% tolerance intervals for individual vector measurements were plotted using R and Xc components standardized by the subject's crown-to-heel length (height). Mean vectors from the groups (1, 2, and 3 to 7 d) with overlapping 95% confidence ellipses were considered representative of only one age class of 1 to 7 d. The impedance vector distribution of neonates also was compared with healthy white children (1014 boys and 1030 girls, age 2-15 y) and adult subjects (354 men and 372 women, age 15-85 y) from the same geographic area. There was a definite, progressive, vector shortening from birth, through ages 2 to 15 y, toward the adults' vector position.

CONCLUSIONS

We established the reference, bivariate, 95%, 75%, and 50% tolerance intervals of the impedance vector in the first postnatal week for healthy white neonates, with which the vectors from infants with altered body composition can be tested (free software is available from apiccoli@ unipd.it).

Determination of triclosan in personal health care products by liquid chromatography (HPLC)

An isocratic reversed-phase liquid chromatographic (HPLC) method is proposed for the practical and reliable determination of triclosan, an antimicrobic agent incorporated into a variety of personal heath care products. Chromatographic separations were performed on a C-18 column using acetonitrile-TEA phosphate (70 mM; pH 3.5) 55:45 (v/v) as mobile phase and UV detection at 230 and 280 nm. The selectivity of the method was assured by the on-line photodiode array detector. The identity of the triclosan peak was also confirmed by HPLC MS. The method was successfully applied to the determination of triclosan in commercially available health care products (deodorant stick, dentifrice gel, mouthrinse, toothpaste and handwash). All the products displayed triclosan concentrations in compliance with the EEC directive (< or = 0.3%,).

Is menopause an independent cardiovascular risk factor? Evidence from population-based studies

The question on whether menopause is an independent cardiovascular risk factor is still under debate. The results of four studies conducted by our staff in North East Italy, including > 11,000 subjects from the general population and covering a range of ages from 18 to 95 years, have been employed. We found apparently higher blood pressure (BP) values in naturally menopausal than in fertile women, but this difference disappeared after age-correction, or after identifying fertile and menopausal age-matched women. Significantly higher levels of serum lipids were also observed in menopausal than in fertile women but, in this case too, any difference disappeared after age-correction/matching. In a 16-year longitudinal analysis we found that BP increase and incidence of hypertension were the same in the women who remained fertile, in those becoming naturally menopausal and in those already menopausal at baseline; going through the menopause period, therefore, has no effect on BP. A mild and transitory BP increase was only observed during the climacterium. The BP increase during a follow-up and the incidence of new cases of hypertension were also similar in the women who remained fertile and in those who underwent bilateral ovariectomy, indicating no direct effect on BP for surgical menopause. In contrast, vectorial analysis demonstrated an excess increment of serum lipids among the women who underwent oophorectomy. In our populations, menopause had no predictive role and was rejected from the multivariate equations of risk, cardiovascular risk being completely explained by age and BP (both higher in menopausal then in fertile women).

Steroid hormones and disease activity during pregnancy in systemic lupus erythematosus

OBJECTIVES

To analyze the variation of steroid hormone levels during pregnancy in patients with systemic lupus erythematosus (SLE). Moreover, to investigate whether, during gestation, there is any relationship between steroid concentration and SLE activity.

METHODS

Seventeen consecutive pregnant SLE patients and 8 matched healthy pregnant controls were studied prospectively. Disease activity was evaluated by European Consensus Lupus Activity Measure (ECLAM) score modified for pregnancy. The following hormones were evaluated: testosterone, 17beta-estradiol (estradiol), cortisol, dehydroepiandrosterone sulfate (DHEAS), and progesterone.

RESULTS

Disease activity score significantly varied during pregnancy and postpartum (P< 0.05), being decreased in the third trimester and increased in the second trimester and postpartum. Serum levels of all steroids varied significantly during pregnancy and the postpartum period both in patients and in healthy subjects. In SLE patients, estradiol, progesterone, and DHEAS concentrations were found to be significantly reduced compared with controls. Serum level profiles of estradiol and progesterone were different from those observed in controls. No differences in the steroid levels were observed between patients taking prednisone <or=5 mg/day or >5 mg/day, apart from cortisol, which was, as expected, lower in the latter group.

CONCLUSIONS

The major hormonal alteration observed during pregnancy in SLE patients was an unexpected lack of estrogen serum level increase, and, to a lesser extent, progesterone serum level increase, during the second and-even more-the third trimester of gestation. This lack of increase probably was due to placental compromise. Therefore, these steroid hormone variations may result in a lower humoral immune response activation, probably related to a change in the estrogen/androgen balance, that in turn could account for the decrease in disease activity observed during the third trimester in pregnant SLE patients.

Impedance vector distribution by sex, race, body mass index, and age in the United States: standard reference intervals as bivariate Z scores

Bioelectrical impedance measurements were collected in the Third National Health and Nutrition Examination Survey (NHANES III), but their results have not been published. In the NHANES III population, resistance (R) and reactance (Xc) values at 50-kHz frequency were obtained with a Valhalla Scientific meter (model 1990B; San Diego, CA, USA). The RXc graph method was used to identify bivariate pattern distributions of mean vectors (95% confidence ellipses by sex, race, age, and body mass index [BMI]), and individual impedance vectors (50%, 75%, and 95% tolerance ellipses). Data from 10 222 adults (5261 men and 4961 women) formed 90 four-way classification groups, with two sexes, three races or ethnicities (non-Hispanic white, non-Hispanic black, Mexican American), five age classes (20-29, 30-39, 40-49, 50-59, and 60-69 y), and three BMI classes (19-24.9, 25-29.9, and 30-34.9 kg/m(2)). Sex, race or ethnicity, BMI and age, in decreasing order, influenced the vector distribution pattern. Mean vectors in women were significantly longer than those in men. Within each sex, the mean vector of non-Hispanic white subjects was shorter and with a smaller phase angle than that of corresponding BMIs from the two other race/ethnic populations. Tolerance ellipses were calculated from sex- and race-specific reference populations 20 to 69 y old and 19 < or = BMI < 30 kg/m(2) (8022 subjects, 4226 men and 3796 women). After transformation of impedance vector components into bivariate Z scores (standardized deviates, as differences from the mean divided by the standard deviation of the reference population), we constructed one standard, reference, RXc-score graph (50%, 75%, and 95% tolerance ellipses) that can be used with any analyzer in any population. The pattern of impedance vector distribution and reference bivariate intervals for the individual impedance vector are presented for comparative studies (free software at E-mail: apiccoli@unipd.it).

Platelet/polymorphonuclear leukocyte adhesion: a new role for SRC kinases in Mac-1 adhesive function triggered by P-selectin

Adhesion of polymorphonuclear leukocytes (PMNLs) to activated platelets requires a P-selectin-triggered, tyrosine kinase-dependent adhesiveness of Mac-1 and is accompanied by tyrosine phosphorylation of a 110-kd protein (P-110) in PMNLs. Inhibitors of SRC tyrosine kinases were found to inhibit PMNL adhesion to activated platelets or to P-selectin expressing Chinese hamster ovary (CHO-P) cells and the tyrosine phosphorylation of P-110. Adhesion of PMNLs to activated platelets or to CHO-P cells stimulated activity of LYN and HCK. Monoclonal antibody blockade of P-selectin or beta2-integrins reduced the activation of both kinases. In PMNLs either adherent to platelets or aggregated by P-selectin-IgG chimera, Mac-1 was rapidly redistributed to the Triton X-100-insoluble cytoskeletal fraction, and large clusters of Mac-1 colocalized with patches of F-actin at the sites of cell-cell contact. In PMNLs stimulated by P-selectin-IgG chimera, SRC kinase inhibition impaired Mac-1 clustering, F-actin accumulation, and CD18 redistribution to the cytoskeleton. Disruption of the actin filament network by cytochalasin D prevented PMNL-platelet adhesion and P-selectin-induced PMNL aggregation and impaired the clustering of Mac-1. In agreement with the requirement for the beta2-integrin in the functional up-regulation of LYN and HCK, integrin blockade by monoclonal antibodies resulted in a complete inhibition of P-selectin-induced Mac-1 clustering and F-actin accumulation. Taken together, the results indicate that, after an initial P-selectin-triggered beta2-integrin interaction with the ligand, SRC kinases are activated and allow the remodeling of cytoskeleton-integrin linkages and integrin clustering that finally strengthen cell-cell adhesion. This model highlights a new role for SRC kinases in a regulatory loop by which the Mac-1 promotes its own adhesive function.

Renal involvement in subjects with peripheral atherosclerosis

BACKGROUND

Ischemic nephropathy is an important cause of renal failure in western countries. Subclinical renal function abnormalities may exist in patients with extrarenal atherosclerosis, and may precede the onset of overt ischemic nephropathy.

METHODS

To assess the impact of extrarenal atherosclerosis on the kidney, we evaluated renal function in 89 subjects with differing degrees of peripheral atherosclerosis, without manifest clinical or laboratory signs of ischemic nephropathy and renovascular hypertension. All laboratory testing, ultrasonography with Doppler analysis for the localization of peripheral vascular disease (carotid and lower limb arteries), and non-invasive evaluation of renal function by radionuclide studies of renal plasma flow (MAG3 clearance) and glomerular filtration (DTPA clearance), as well as total, LDL and HDL cholesterol, and triglycerides were determined; smoking habit was recorded. By combining sonographic data on arterial tree stenosis (ATS), the subjects were grouped according to the atherosclerotic vascular damage (ATS involvement).

RESULTS

Despite no change in plasma creatinine and DTPA clearance (from 91.58+/-26.53 mL/min/1.73 m2 to 93.47+/-24.82), MAG3 clearance progressively declined with the severity of vascular damage (from 244.86+/-60.60 mL/min/1.73 m2 to 173.59+/-58.74). Stepwise multiple regression analysis indicated that MAG3 clearance was best explained by ATS involvement (standardized beta coefficient -0.40; p<0.001), smoking habit (-0.34; p= 0.004), and serum LDL-cholesterol (-0.24; p<0.035).

CONCLUSIONS

The renal hemodynamic profile in atherosclerotic patients might constitute functional evidence of the silent phase of ischemic renal disease. The findings suggest that renal function should be carefully assessed in patients with extrarenal atherosclerosis, particularly in those with classic cardiovascular risk factors.

BMI centile as an indicator of degree of obesity in childhood

OBJECTIVE

To evaluate body mass index (BMI centile) as an indicator of degree of obesity in childhood.

DESIGN

Random.

SETTING

Obese and nonobese healthy children were recruited in the Verona University Department of Pediatrics and Division of Pediatrics of the Verona City Hospital.

SUBJECTS AND METHODS

70 males aged 9.7 +/- 2.75 years and 55 females aged 9.9 +/- 3 years. Percentage fat mass was estimated by bioelectrical impedance analysis using Kushner's equation, and Italian BMI charts (A. Luciano et al. 1997) were used to calculate the BMI centile (BMI > 90 degrees in 76 subjects and BMI < 90 degrees in 59 subjects).

RESULTS

Linear regression analysis and correlations between percentage fat mass and BMI centile were significant in males (P = 0.000, r = 0.6) and females (P = 0.000, r = 0.7) in both obese and nonobese subjects.

CONCLUSIONS

BMI is a reliable, easy-to-use indicator of degree of obesity in childhood. Pediatricians should be encouraged to use BMI centiles to assess childhood obesity and particularly the onset of overweight, its evolution and its response to different types of management.

Endothelial dysfunction in small resistance arteries of patients with non-insulin-dependent diabetes mellitus

OBJECTIVE

Arterial hypertension is frequently associated with the presence of endothelial dysfunction in human subcutaneous small resistance arteries, as evaluated by responses to acetylcholine or bradykinin; however it is not known whether patients with diabetes mellitus show similar alterations. Therefore, we have investigated endothelial function in subcutaneous arteries of normotensive subjects (NT), of patients with essential hypertension (EH), of patients with non-insulin-dependent diabetes mellitus (NIDDM), as well as of patients with both essential hypertension and non-insulin-dependent diabetes mellitus (NIDDM+EH).

PATIENTS AND METHODS

All subjects were submitted to a biopsy of the subcutaneous fat Small arteries were dissected and mounted on a micromyograph. The media to lumen ratio (M/L) was calculated. A concentration-response curve to acetylcholine, to bradykinin as well as to the endothelium-independent vasodilator sodium nitroprusside were performed. We also evaluated the contractile response to endothelin-1. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) plasma levels were also measured.

RESULTS

The vasodilatation to acetylcholine and bradykinin (but not to sodium nitroprusside) was significantly and similarly reduced in EH, in NIDDM, and in NIDDM+EH compared with NT. The contractile response to endothelin-1 was similarly reduced in EH, in NIDDM and in NIDDM+EH. Plasma ICAM-1 and VCAM-1 concentrations were higher in EH, NIDDM and NIDDM+EH than in NT.

CONCLUSIONS

An evident endothelial dysfunction was detected in patients with NIDDM, and the simultaneous presence of EH did not seem to exert an additive effect. The contractile responses to endothelin-1 were reduced possibly as a consequence of ET(A) receptor down-regulation.

Plasma protein synthesis in patients with low-grade nephrotic proteinuria

Overt nephrotic syndrome is characterized by albumin and fibrinogen hyperproduction and reduced very low density lipoprotein apolipoprotein B-100 (VLDL apoB-100) clearance. Whether similar changes also occur in low-grade proteinuria is not known. Thus we measured albumin, fibrinogen, and VLDL apoB-100 kinetics in six patients with modest proteinuria and normal creatinine clearance (P) and in ten control subjects (C) by leucine tracer infusion and precursor-product relationships. In P, plasma albumin concentration was decreased (P < 0.003), whereas concentrations of fibrinogen and VLDL apoB-100 were increased (P < 0.001). In P, albumin fractional secretion rate (FSR) was increased (P < 0.01), fibrinogen FSR was normal, and VLDL apoB-100 FSR was decreased (P < 0.03). As a result, in P, absolute secretion rates (ASR) of albumin and fibrinogen were increased (P < 0.03), whereas VLDL apoB-100 ASR was normal. Albumin FSR was inversely correlated to oncotic pressure in P but not in C. These findings suggest that low-grade nephrotic proteinuria is characterized by simultaneous multiple alterations in turnover rates of albumin, fibrinogen, and VLDL apoB-100. Their pathogenesis, however, appears to be multifactorial.

Blood pressure and metabolic profile after surgical menopause: comparison with fertile and naturally-menopausal women

In 1978 a random sample (367 men and 568 women aged 18-65 years) taken from the general population of a north-eastern Italian town was screened for cardiovascular risk; 16 years later, the women were invited to a second screening. Three groups were identified at the initial screening (fertile, naturally menopausal and surgically menopausal) and four in the longitudinal study (137 remained fertile during the whole study, 205 became naturally menopausal, 56 were ovariectomised and 127 were already going through the menopause). The protocol included a questionnaire, blood pressure (BP) measurement, and blood exams. Continuous variables were adjusted for confounders. Systolic BP, prevalence of hypertension, cholesterol, glycaemia and uricaemia were similar, whereas diastolic and triglycerides (TG) were lower in surgically-menopausal than in fertile women (P < 0.001). No significant difference in 16 years' variation from baseline was observed between the four groups, although women who remained fertile showed the smallest increases. In particular, neither systolic or diastolic BP increases differed between the women who were oophorectimised and those who remained fertile. 'Fertile status' was rejected from the logistic equation of incidence of hypertension, and 'age of menopause' was also rejected when this analysis was repeated in ovariectomised women. New coronary artery disease (angina pectoris or myocardial infarction) was observed in one ovariectomised woman, in three naturally menopausal, and in 13 already menopausal women which seemed to reflect the age trend. No new cases were observed in women who remained fertile. In conclusion, in Italian women surgical menopause, similarly to natural menopause, is devoid of any negative prognostic effect. Journal of Human Hypertension (2000) 14, 799-805

Elementary clinical decision analysis in evidence-based nephrology

To assess the potential contribution of elementary decision analysis to evidence-based medicine in nephrology, the treatment of primary membranous nephropathy with nephrotic syndrome is taken as an example involving quantity and quality of life, and the treatment of uremic anemia in hemodialysis patients as an example involving economic constraints of interventions. Technical details on decision tree calculation procedures, outcome quantitative assessment, and probability assignment to branches are outlined. Indications strictly based on significance tests of individual outcomes of randomized controlled trials can either miss clinical advantages or disregard economic constraints that can be easily established by decision analysis and that may have a major impact in practice.

Time course of apoptosis in small resistance arteries of spontaneously hypertensive rats

OBJECTIVE

The time course of programmed cell death (apoptosis) in the vasculature of spontaneously hypertensive rats (SHRs) is still unclear. Moreover, no data are presently available about the possible inter-relationships between apoptosis and vascular remodelling. The aim of this study was to investigate the mesenteric small resistance arteries and large arteries (aortas) of SHRs and normotensive Wistar-Kyoto (WKY) rats at different ages, before and after the development of overt hypertension.

METHODS

Twenty-four SHRs (4, 8 or 12 weeks old) and 24 age-matched WKY rats were included in the study. Blood pressure was measured non-invasively. Rats were killed by decapitation and segments of aortas and small mesenteric arteries were dissected free from the surrounding tissue. Mesenteric arteries were mounted on a micromyograph and structural characteristics were measured (media thickness, media:lumen ratio, etc.). Apoptotic cells in the tunica media of large and small vessels were then stained using modified TdT-mediated dUTP Nick-End Labeling (TUNEL).

RESULTS

At 4 weeks of age no difference in the blood pressure and percentage of apoptosis in mesenteric arteries between SHRs and WKY rats was detected; however, the media:lumen ratio of mesenteric small resistance arteries was significantly greater in SHRs. At 8 and 12 weeks of age systolic blood pressure, media:lumen ratio and apoptosis rate in mesenteric small arteries was significantly higher in SHRs. The rate of apoptosis in the aortas was similar in the two strains at all three ages.

CONCLUSIONS

An increased prevalence of apoptosis was observed in mesenteric small arteries of 8- and 12-week-old SHRs. It is possible that apoptosis may exert a role in small resistance artery remodelling during the development and establishment of hypertension.