Evaluation of the K-wire technique for external urinary drainage in pediatric laparoscopic pyeloplasty.

INTRODUCTION: Urinary drainage is usually left in place after laparoscopic pyeloplasty to limit the risk of complications, such as urinary leakage. The procedure is sometimes laborious and complications may occur. PURPOSE: Prospective evaluation of the Kirschner technique for urinary drainage during pediatric laparoscopic pyeloplasty. STUDY DESIGN: This technique (Upasani et al., J Pediatr Urol 2018) involves introducing a nephrostomy tube (Blue Stent) with a Kirschner wire during laparoscopic transperitoneal pyeloplasty. We evaluated this technique by analyzing 14 consecutive pyeloplasties (53% on female patients, median age 10 years (6-16 years), on the right side in 40%) performed by a single operator between 2018 and 2021. The drain and urinary catheter were clamped and the perirenal drain removed on day 2. The stent was removed during consultation between days 7 and 15. RESULTS: The median duration of surgery was 155 ± 7 min. Urinary drainage was installed within 5 min, without the need for radiological control and with no complications. All drains were correctly placed, with no drain migration or urinoma. Median hospital stay was 2 ± 1 days. One patient developed pyelonephritis (D8). The stent was removed without difficulty or complications. One patient presented an 8-mm lower calyx urinary stone at two months, revealed by macroscopic hematuria, necessitating extracorporeal shock wave lithotripsy. DISCUSSION: The study design was based on a homogeneous series of patients, without comparison with another drainage technique or procedures performed by another operator. A comparison with other techniques might have been informative. Before this study, we tested various types of urinary drainage, to optimize performance. This technique was considered the simplest and least invasive. CONCLUSION: External drain placement with this technique was rapid, safe, and reproducible in children. It also made it possible to test the tightness of the anastomosis and to avoid the need for anesthesia for drain removal.

Sialic acid content of LDL in coronary artery disease: no evidence of desialylation in subjects with coronary stenosis and increased levels in subjects with extensive atherosclerosis and acute myocardial infarction: relation between desialylation and in vitro peroxidation.

We recently showed that sialic acid content of LDL was not a marker of early cardiovascular disease (Arterioscler Thromb Vasc Biol. 1995;15:334-339). Here, we investigated this parameter in patients with advanced coronary artery disease (CAD). We first examined 100 patients having undergone coronary angiography. The distribution of LDL sialic acid values was very similar in subjects with no coronary stenosis (31.3+/-3.7 nmol/mg LDL protein, mean+/-SD) and those with > or = 75% stenosis in at least one main coronary artery or > or = 50% stenosis in at least two main coronary arteries (32.1+/-5.5 nmol/mg LDL protein). In contrast, LDL sialic acid content was significantly increased in patients with both coronary stenosis and peripheral arterial atherosclerotic lesions compared with those with either no lesion or only one or the other type of lesion. We then examined LDL sialic acid content in 20 patients with acute myocardial infarction. LDL sialic acid content was significantly higher (35.9+/-3.2 nmol/mg LDL protein) than that in the CAD(-) control group. These data suggest that LDL sialic acid content increases with the extension of atherosclerosis and its progression to acute complications. To explain the discordance with Orekhov and coworkers (Atherosclerosis. 1991;86:153-161), who showed that LDL sialic acid content in patients with advanced CAD was lower than that in healthy subjects, we studied the time courses of sialic acid, TBARS, and vitamin E levels in LDL dialyzed in different experimental conditions. A continuous decrease in both sialic acid and vitamin E levels and an increase in TBARS levels were observed in LDL samples containing less than 1 mmol/L EDTA, the intensity and rapidity of which varied with the EDTA concentration in the buffer. Our data support the idea that desialylation may result from in vitro peroxidation of LDL.

Oxidative modification of low-density lipoprotein by the human hepatoma cell line HepG2.

The human hepatoblastoma cell line HepG2 is a liver model commonly used for lipid metabolism studies. Numerous cell types have been found to oxidize low-density lipoprotein (LDL) but, to our knowledge, the effects of HepG2 cells on LDL have not been investigated. We found that LDL is modified by HepG2 cells through a peroxidative mechanism, as judged by an increase in TBARS content (which was prevented in the presence of the antioxidants vitamin E, 2,6-di-tertbutyl-cresol and probucol), increased degradation by J774 macrophages, decreased internalization by MRC5 fibroblasts, and aggregation of apo B. Aspirin and allopurinol, which inhibit cyclooxygenase and xanthine-oxidase activities, respectively, had no effect on HepG2-induced LDL modification, and neither did catalase, which dismutates hydrogen peroxide; or mannitol, which scavenges hydroxyl radicals. In contrast, superoxide dismutase, a superoxide anion scavenger, and glutamate and threonine, which alter cellular cystine uptake, prevented LDL modifications, as did the removal of cysteine/cystine from the culture medium. Oxidation of LDL by HepG2 cells might thus involve superoxide anion production and/or thiol metabolism.

A cytotoxic electronegative LDL subfraction is present in human plasma.

By using fast protein liquid chromatography, we isolated from human plasma a minor electronegative LDL subfraction designated LDL(-). After immunoaffinity chromatography against apolipoprotein (apo)(a) and apo A-I, LDL(-) represented 6.7 +/- 0.9% (mean +/- SD; n = 18) of total LDL. Compared with the major LDL subfraction, designated LDL(+), LDL(-) contained similar amounts of thiobarbituric acid-reactive substances, conjugated dienes, and vitamin E and had a similar lipid/protein ratio and mean density. Moreover, the apo B of LDL(-) was not aggregated and its LDL receptor-binding activity was slightly increased. These results were consistent with the nonoxidized nature of LDL(-). LDL(-) showed increased contents of sialic acid (38.1 +/- 5.2 versus 28.9 +/- 3.3 nmol/mg protein; n = 7; P < .01), apo C-III (1.43 +/- 0.21% versus 0.14 +/- 0.04%; n = 7; P < .01), and apo E (1.64 +/- 0.26% versus 0.10 +/- 0.05%; n = 7; P < .0005). Compared with LDL(+), LDL(-) displayed enhanced cytotoxic effects on cultured human umbilical vein endothelial cells, as shown by lactate dehydrogenase assay (P < .003; n = 6), neutral red uptake (P < .02; n = 6), and morphological studies. We also studied the relationship of LDL(-) to age and plasma lipid levels in 133 subjects. The percentage of contribution of LDL(-) to total plasma LDL correlated with age (P < .05), total cholesterol (P < .05), and LDL cholesterol (P < .003). In conclusion, this study shows that LDL(-), a circulating human plasma LDL, is an electronegative native LDL subfraction with cytotoxic effects on endothelial cells. This subfraction, which correlates positively with common atherosclerotic risk factors, might induce atherogenesis by actively contributing to alteration of the vascular endothelium.

[Charge heterogeneity of low density lipoproteins]. / Hétérogénéité de charge des lipoprotéines de basse densité (LDL).

Traditionally, low-density lipoprotein (LDL) are separated with respect to their size, density and apolipoprotein composition. Fractionation of LDL according to their electrical charge is also interesting as modified LDL have been implicated in the onset of atherosclerosis. This review discusses possible mechanisms underlying charge heterogeneity of human plasma LDL, such as oxidation, glycation, conjugation with aldehydes, carbamylation and changes in sialic acid content and protein composition.

Characteristics of ten charge-differing subfractions isolated from human native low-density lipoproteins (LDL). No evidence of peroxidative modifications.

Native plasma low-density lipoproteins (LDL) were fractionated into ten subfractions with increasingly negative charges (LDL-1, the least electronegative, to LDL-10) using an anion-exchange column coupled to a fast protein-liquid chromatography system. Prior to fractionation, contaminating Lp(a) and apo A-I-containing lipoproteins were removed from LDL preparations by immunoaffinity chromatography. No significant difference in thiobarbituric acid-reactive substances, vitamin E or free aminogroup was found among subfractions, and no peptide with a higher molecular weight than apo B was observed on SDS-PAGE. We observed a gradual increase in cholesterol esters and a concomitant decrease in triglycerides from LDL-1 to LDL-7, and a reverse tendency from LDL-8 to LDL-10 (P < 0.01). Free cholesterol increased linearly from LDL-1 to LDL-10 (P < 0.01). LDL-1 to -3 had a homogeneous density profile, while other more electronegative subfractions showed a bimodal distribution with a second, minor peak of slightly higher density. A gradual increase in apolipoprotein C-III content related to LDL electronegativity was observed (P < 0.001). Apolipoprotein E content was also increased in the last two subfractions (P < 0.01). LDL subfractions displayed a similar binding fate on human fibroblasts, with the exception of the most electronegative subfractions [LDL-(9 + 10)], which bound more actively to apo B/E receptors (P < 0.05). This study shows that charge heterogeneity of native LDL is not related to lipid peroxidation or derivatization of free aminogroups of apolipoprotein B. In contrast, the enrichment of LDL in apolipoproteins other than apo B may explain, in part, the difference in their particle charge.

Evaluation of the sialic acid content of LDL as a marker of coronary calcification and extracoronary atherosclerosis in asymptomatic hypercholesterolemic subjects. PCVMETRA Group.

Recent studies have shown that the sialic acid content of LDL isolated from patients with angiographically demonstrated advanced coronary atherosclerosis is lower than that of LDL isolated from healthy subjects. These observations raise the question as to whether LDL sialic acid content could be used as an early marker of atherosclerosis. We screened for carotid, aortic, and femoral plaques by ultrasonography and for coronary calcifications by ultrafast computed tomography in 160 hypercholesterolemic subjects free of cardiovascular disease to investigate the relation between LDL sialic acid content and the prevalence of these early atherosclerotic lesions. LDL sialic acid values varied from 19.6 to 46.6 nmol/mg LDL protein (33.9 +/- 4.4, mean +/- SD) in the whole population, but the distribution was very similar: (1) in subjects with no plaque (34.1 +/- 4.9) relative to those with one or several plaques at one (34.2 +/- 4.4), two (33.0 +/- 3.6), or three (34.8 +/- 3.4) different arterial sites; (2) in subjects with (33.9 +/- 3.7) and without (34.1 +/- 4.8) coronary calcification; and (3) in subjects with both extracoronary and coronary lesions (33.8 +/- 3.9) relative to those with no arterial lesions (34.2 +/- 4.5). LDL sialic acid content was not related to sex, age, body mass index, smoking, blood pressure, or serum total cholesterol and lipoprotein(a) levels but correlated negatively with serum triglyceride levels (P < .001). These results suggest that LDL sialic acid content is not a discriminant marker of early atherosclerosis in asymptomatic hypercholesterolemic subjects.

In-vitro activity of azithromycin against Chlamydia trachomatis.

We evaluated the efficacy of azithromycin, erythromycin and doxycycline in controlling in-vitro propagation of Chlamydia trachomatis in HeLa 229 cells. Eight recent clinical isolates of C. trachomatis and two fast-growing strains were tested with inocula of 10(3)-10(5) inclusion forming units per well of a 96-well microtitre plate. C. trachomatis inclusions were detected by an immunoperoxidase-antiperoxidase procedure (PAP), including a genus-specific monoclonal antibody. MIC ranges were 0.064-0.25 mg/l azithromycin, 0.064-0.128 mg/l erythromycin and 0.016-0.064 mg/l doxycyline; MBC ranges were 2-8 mg/l azithromycin, 4-64 mg/l erythromycin and 0.5-8 mg/l doxycycline. Since azithromycin appears to be effective against C. trachomatis, clinical studies in sexually transmitted diseases are indicated.