Computerized artifact detection and correction of uroflow curves: towards a more consistent quantitative assessment of maximum flow.

OBJECTIVES: To evaluate a computerized method of artifact detection and correction of uroflow and compare the quantitative assessment of maximum flow obtained by the computer with visual correction by experts. METHODS: A total of 90 randomly chosen flows was scanned into the computer whereafter automated artifact detection and correction was performed according to pre-established rules implemented in the software. Three experts visually corrected the flows using the same artifact detection and correction specifications as the computer. Measuring agreement between different methods of assessment of maximum flow was evaluated by calculating the difference and the standard deviation (SD) of the differences. The repeatability of assessing the maximum flow value by the computer and by expert 1 was assessed by calculating the difference between 2 readings and the coefficient of repeatability. RESULTS: The coefficient of repeatability of maximum flow after detection and correction of artifacts by the computer (0.38 ml/s) was slightly better when compared with the coefficient of repeatability between 2 observations by 1 expert (1.12 ml/s). The interobserver variation for the quantitative assessment of maximum flow appeared to be great. A total of 51% of the maximum flow values assessed by expert 2 was 1 ml/s or more greater than those assessed by expert 1. When comparing the results of the computer with those of the experts, the mean value of maximum flow from expert 1 was 0.71 ml/s smaller than the computer value (p < 0.01), the mean value from expert 2 was 0.53 ml/s greater (p < 0.01) and the mean value from expert 3 was not significantly different (0.25 ml/s greater). The SD of maximum flow after correction by the computer was 0.3 ml/s smaller than the SD of the raw data from the flowmeter and the corrected values by 2 experts. CONCLUSIONS: Computerized artifact detection and correction eliminates an important fraction of the variability of manually corrected maximum flow values. This may lead to smaller sample size requirements, especially in studies where the primary objective is to assess a small (+/- 1 ml/s) difference in mean maximum flow between groups.

Effect of intravenous alfuzosin on urethral pressure in patients with neurogenic bladder dysfunction. DORALI Study Group.

In order to assess the ability of a single intravenous (i.v.) injection of alfuzosin, a selective alpha-1 blocker, in reducing high urethral tone in patients with symptomatic neurogenic bladder dysfunction (NBD), 163 patients (mean maximal urethral pressure [MUP] 108 +/- 46 cm H2O) were enrolled in a double-blind, placebo-controlled, parallel-group trial and were randomly allocated to receive 0.5 mg (n = 45), 1 mg (n = 41), 2 mg (n = 39) alfuzosin or placebo (n = 38). The decrease in MUP was dose-dependent and statistically significant (P < or = 0.05) for 1 and 2 mg alfuzosin (respectively, 43 +/- 28 cm H2O and 46 +/- 27 cm H2O decreases vs. baseline) in comparison with placebo (23 +/- 30 cm H2O). The 2 mg dose level was the most effective leading to a > or = 30 or 50% decrease in MUP in, respectively, 69 and 44% of patients. The safety of all three alfuzosin dose levels was satisfactory and comparable to placebo. I.v. alfuzosin induces, in a dose-related manner, a clinically significant decrease in urethral pressure in patients with NBD and high urethral tone, and may be safely used as a pharmacological test as part of an urodynamic investigation.

Isotype and affinity of anti-myeloperoxidase autoantibodies in systemic vasculitis.

The role of immunoglobulin (Ig) isotype and affinity of antimyeloperoxidase (MPO) antibodies in the clinical expression of vasculitis (organ involvement, severity and evolution) remains incompletely defined. We have determined the anti-MPO antibody isotypes, as well as the apparent affinity constant (aK) of anti-MPO IgG by using fluid phase MPO inhibition of IgG binding in an MPO specific ELISA. Twenty-eight patients with anti-MPO antibodies and necrotic and crescentic glomerulonephritis, either isolated or associated to various other organ localizations, were analyzed. Serum samples were obtained before treatment and during follow-up. No association was observed between the isotype, the level or apparent affinity of anti-MPO antibodies and the clinical symptoms, severity, and organ distribution of vasculitis, including alveolar hemorrhage. No significant correlation was found between the apparent affinity and the level of anti-MPO IgG. However, the presence of anti-MPO IgM was clearly associated with low affinity anti-MPO IgG and vice versa. Furthermore, in a longitudinal study, high levels of anti-MPO IgM, when present, were observed early in the course of the disease and in some cases preceded the reappearance of anti-MPO IgG during relapses. High affinity anti-MPO IgG were usually present before treatment. Immunosuppressive therapy resulted in decreased apparent affinity and level of anti-MPO IgG. Importantly, anti-MPO IgG level increased during relapses but the affinity of these IgG autoantibodies remained low.(ABSTRACT TRUNCATED AT 250 WORDS)

Decrease of tumor-like calcification in uremia despite aggravation of secondary hyperparathyroidism: a case report.

Extraskeletal pseudotumoral calcifications generally develop in uremic patients with a high calcium x phosphorus (Ca x P) product and severe secondary hyperparathyroidism. In the present case report we describe a chronic hemodialysis patient presenting with a massive calcification of the left shoulder region, severe aluminum (Al) intoxication and moderate hyperparathyroidism. Her initial serum Ca x P product was only slightly elevated: 5.01 mmol2/l2. Under deferoxamine treatment during the subsequent 4 months, Al overload decreased. On the other hand, parathyroid overfunction worsened, as reflected by an increase of the serum immunoreactive parathyroid hormone [1-84] level from initially 690 to 1052 pg/ml (normal, 15-60 pg/ml) and an increase of alkaline phosphatase activity, and plasma calcitriol increased from undetectable to a low-normal value. Predialysis serum total Ca levels decreased rapidly from 2.9 to 2.5 mM but serum P concentrations remained elevated: 1.6-2.5 mM. Unexpectedly, the extent of the periarticular calcification diminished considerably during the same time period. The present observation shows that in a subset of uremic patients with Al overload, pseudotumoral calcifications may regress during Al chelation therapy despite progression of hyperparathyroidism. Since Al may predispose collagen to develop dystrophic or metastatic calcification, it is suggested that this process is reversible by correcting Al intoxication.

Antigen specificities and clinical distribution of ANCA in kidney diseases.

The antigenic specificity and clinical distribution of the antineutrophil cytoplasmic antibodies (ANCA) in kidney diseases have recently been extensively studied. In patients with systemic vasculitis, the great predominance of two major ANCA antigens, proteinase 3 (PR3) and myeloperoxidase (MPO), is now established. PR3 and MPO are colocalized in the azurophilic granules of neutrophils and translocated to the cell surface during activation, and thus are able to interact with autoantibodies after neutrophil preactivation. Furthermore, by comparison of amino acid and DNA sequences, it has been shown that PR3 is identical to myeloblastin, which has been described independently and is involved in the control of growth and differentiation of leukemic cells. Aside from the two major ANCA antigens, a number of neutrophil cytoplasmic antigens recognized by ANCA have been identified, including human leukocyte elastase, lactoferrin, CAP57, and cathepsin G. These rare ANCA specificities occur in a limited number of patients. The variety of ANCA antigen specificities contrasts, however, with the fact that the vast majority of ANCA-positive sera are monospecific for one single ANCA antigen. With regard to clinical distribution, ANCA have major diagnostic significance in the four conditions in which they are frequently detected: Wegener's granulomatosis (WG), Churg and Strauss Syndrome (CSS), microscopic periarteritis (MPA), and necrotic and crescentic glomerulonephritis (NCGN). However, the initial dichotomy between MPO-associated vasculitis (NCGN, MPA) and that associated with anti-PR3 antibodies (WG) appears far from absolute.

Genetic analysis of CR1 (the C3b complement receptor, CD35) expression on erythrocytes of HIV-infected individuals.

The number of C3b receptor (CR1) molecules on erythrocytes is genetically determined by two codominant autosomal alleles. The genetic polymorphism of CR1 expression correlates with a Hind III restriction fragment length polymorphism (RFLP) of the CR1 gene. The relative frequency of individuals homozygous for the allele coding for low CR1 numbers is approximately 5% of the normal population. CR1 numbers/erythrocytes are significantly decreased in symptomatic HIV-infected individuals. Decreased CR1 expression correlates with the severity of disease. The present study investigated the CR1 genomic Hind III RFLP-related polymorphism in 79 HIV-infected individuals and 84 healthy subjects. Allele frequencies were found to be similar in both populations. Thus, there is no susceptibility nor resistance to HIV-infected linked to the CR1 gene. Defective expression of CR1 in HIV-infected patients is acquired through central and/or peripheral mechanisms.

[Ankylosing spondylitis with type AA amyloidosis. 6 cases]. / Spondylarthrite ankylosante avec amylose de type AA. Six observations.

The authors have studied 6 cases of systemic AA amyloidosis associated with ankylosing spondylitis. Renal failure occurred in all patients a mean of 19 years after the clinical onset of the rheumatic disease. Three patients progressed rapidly (between 3 months and 3 years) to end-stage renal failure. Such an outcome did not depend upon early onset of the renal impairment, degree of inflammation or treatment with colchicine. All patients were alive 2 to 10 years later, and this confirms a better prognosis than with AL amyloidosis. The utility of combining Wright's permaganate reaction with immunological methods to characterize the amyloid deposits was also confirmed. It is concluded that amyloidosis is a rare complication of ankylosing spondylitis and probably depends on a genetic predisposition. The possibility of amyloidosis should be kept in mind when proteinuria or renal failure appear in the course of ankylosing spondylitis.

[Hepatic involvement in HIV 1 virus infection]. / Atteintes hépatiques au cours de l'infection par le virus HIV1.

One hundred consecutive patients with serum antibodies against HIV 1 were evaluated for the prevalence and the type of liver injury. According to the CDC classification, 16 patients belonged to group II (asymptomatic patients), 47 to group III (persistent generalized lymphadenopathy) and 37 to group IV (11 constitutional disease, 19 secondary infectious diseases, 5 secondary cancers, one chronic lymphoid interstitial pneumonitis and one visceral leishmaniasis). Liver histology was studied in 32 patients. Clinical, biological and histologic abnormalities were assessed according to the clinical group and to the number of T4 lymphocytes. The prevalence of HBV infection was determined by HBV DNA and monoclonal antibodies. Clinical hepatic abnormalities were rare (13 p. 100) and no difference was found between groups. Transaminases or GGT activities were elevated in 60 p. 100 of all cases. Serum GGT activity was higher and serum albumin lower in patients in group IV. HBV infection markers were less frequently found in patients with opportunistic infection (74 p. 100) than in asymptomatic patients (100 p. 100; p less than 0.05). Prevalence of serum HBsAg detected by poly- or monoclonal antibodies was very high (29 p. 100) in all clinical groups. Prevalence of serum HBsAg detected only by monoclonal antibodies (10 p. 100) suggest infection of these patients by an HBV variant. Of the 32 patients undergoing liver histology, only 5 (16 p. 100) had signs of activity. There was no association between clinical or histologic signs and the number of T4 lymphocytes per ml. Alkaline phosphatase, ASAT and GGT activities were higher and serum albumin lower in patients with less than 200 T4 lymphocytes per ml.