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Biomedical subjects

J R Salcedo

Publications and source records attributed to J R Salcedo.

At least 19 recordsLinked to original sources

Maternal cocaine abuse and fetal renal arteries: a morphometric study.

The purpose of the present study was to evaluate the pathological findings and perform morphometric analysis of the renal arteries of fetuses exposed to cocaine in utero. The control group consisted of 22 stillborn fetuses of unknown etiology whose mothers' urine was negative for cocaine or any other vasoactive substances. The study group comprised 29 stillborn fetuses whose mothers' urine was positive only for cocaine on the day of admission. Sections of fetal kidneys (4 microm), stained with hematoxylin and eosin and periodic acid-Schiff reagent, were examined under light microscopy (x40) to identify interlobular arteries. Morphometric analysis of these arteries was performed using a self-assembled system with a touch-sensitive screen as an interactive peripheral. Their inner and outer circumferences were measured by outlining them on the screen with a stylus. The radius (r) was calculated from the measurement of the circumference (2.pi.r). The difference of the radii of the outer and inner circumferences was the thickness of the arterial wall. The interlobular arterial thickness was significantly greater (P<0.001) in the cocaine-exposed group (mean 15.46+/-5.8 microm, 2SD) compared with the normal (mean 9.03+/-3.96 microm, 2SD). There was a significantly (P<0.001) positive relation with advancing gestational ages in both groups. The circumferences of the lumen of the arteries showed a significant (P<0.05) relation with advancing gestational ages in the normal group only. In the cocaine-exposed group, the arterial lumen circumference (mean 167.88+/-17.58 microm, 2SD) was significantly (P<0.001) smaller than in the normal group (mean 227.73+/-6.82 microm, 2SD). Thus, maternal cocaine abuse is associated with thickening of the interlobular arterial wall of the fetal kidney and narrowing of the lumen.

Cocaine↗

Nephrosis in childhood.

Succinct aspects of clinical features, pathophysiology and prognosis of nephrotic syndrome in childhood, and indications for performing renal biopsy are enumerated in this review. Orthodox treatment of the nephrotic syndrome with more recent therapeutic approaches, and the role of diuretics, albumin infusions and immunizations in patients with the nephrotic syndrome are reviewed. The etiology of peritonitis, acute renal failure, and renal transplantation are re-examined to update nephrologists on the associated complications of this common childhood disease.

Child↗

Hyperlipidemia in childhood nephrotic syndrome.

Hyperlipidemia is an important characteristic of nephrotic syndrome (NS). Elevation of plasma total cholesterol, or more specifically low-density lipoprotein cholesterol, is the major lipid abnormality in NS, although hypertriglyceridemia may develop as the disorder progresses. The pathophysiology of nephrotic hyperlipidemia is complex. The prevailing view is that both hepatic synthesis of lipids and of apolipoproteins is increased, and that the clearance of chylomicrons and very low-density lipoproteins is reduced. The precise contribution of increased lipogenesis and decreased lipid catabolism to hyperlipidemia, and their relationship to urinary protein loss, hypoalbuminemia and reduced serum oncotic pressure remain controversial. There are two potential risks of elevated plasma lipids: atherosclerosis and progression of glomerular injury. Although neither of these complications has been proved with certainty, there is growing evidence that both may be long-term consequences of NS. Therefore, the diagnosis and treatment of lipid abnormalities, important aspects of the management of nephrotic children, is summarized here to provide pediatric nephrologists with an informed choice.

Child↗

Intravenous immunoglobulin in minimal change nephrotic syndrome: a crossover trial.

To determine whether intravenous immunoglobulin (IVGG) would be an efficacious adjunct in the treatment of childhood minimal change nephrotic syndrome (MCNS), we enrolled ten patients with frequently relapsing or steroid-dependent MCNS in a double-blind crossover clinical trial. At the time of relapse of the nephrotic syndrome, patients were assigned to treatment with a single outpatient infusion of IVGG (800 mg/kg) or intravenous albumin as a control. The relapse was treated concurrently with standard doses of oral prednisone. At the time of the next relapse, patients who had first received IVGG were treated with albumin, and vice versa. There were no significant differences in the length of remission between the IVGG and albumin treatments. The study had a power of 0.72 to detect a true difference of 45 days between the two therapies. We conclude that in the dose of drug used in this trial, administered at the time of relapse in conjunction with prednisone therapy to children with frequently relapsing or steroid-dependent MCNS, IVGG does not lead to a clinically important extension of the period of remission.

Adolescent↗

Calcium-activated potassium channels in human platelets.

The cationic fluorescent probe, DiSC3(5) was used to measure the membrane potential in human platelets. Hyperpolarization was induced by the addition of Ca2+ to the medium and also by the addition of the Ca2+ ionophore, A23187. In the absence of extracellular Ca2+ ([Ca2+]o) there was no response to A23187. The threshold concentration for [Ca2+]o was 20 microM and for A23187 was 12 nM. The increase polarity induced by [Ca2+]o was not affected by various K+ channel blockers. However, the effect of A23187 was inhibited by quinine and charybdotoxin, while apamin, tetraethylammonium, and the calmodulin inhibitors trifluoperazine and compound R24571 were ineffective. The resting membrane potential was -66 +/- 0.9 mV and was decreased by quinine. There are three conclusions from this study: (i) Ca2+-activated K+ channels exist in human platelets; (ii) they are the type that are apamin insensitive, charybdotoxin sensitive; and (iii) they may contribute to the resting membrane potential.

Adult↗

Renal histology of mucocutaneous lymph node syndrome (Kawasaki disease).

Renal involvement is well described in patients with mucocutaneous lymph node syndrome (MCLNS), or Kawasaki disease and is manifested by mild azotemia, hematuria, pyuria or cylinduria, and more often, proteinuria. Renal morphology during the acute stages of the illness has never been reported. In this paper we describe the renal histopathologic changes in a child with MCLNS. The glomerular histopathologic findings suggest immune complex damage to the kidney as a possible mechanism of nephrotoxicity in MCLNS. Presence of kidney lesions, which speak in favor of the injurious role of immune complexes in MLCNS may be relevant to the understanding of the pathogenesis of the vascular lesions that are characteristic of this disease.

Antigen-Antibody Complex↗

Urinothorax: report of 4 cases and review of the literature.

Urinothorax should be considered when pleural effusion occurs in patients with urinary tract obstruction accompanied by retroperitoneal urinoma. This recommendation is based on our experience with 4 cases and a review of the literature. In 2 patients urinary obstruction was owing to retroperitoneal fibrosis secondary to malignancy, including one who had a neuroectodermal undifferentiated small round cell tumor and the other who had a metastatic epithelial neoplasm. In the 2 other patients urinary obstruction resulted from a failed ureteroneocystotomy following renal allograft transplantation. All 4 patients had a urinoma, which may be a predisposing factor to urinothorax.

Adolescent↗

Accelerated recovery from immune-mediated thrombocytopenia with plasmapheresis.

Autoimmune thrombocytopenia unresponsive to corticosteroid therapy developed in a 16-year-old female with long-standing Sjögren's syndrome. Serial plasma exchange caused a linear decrease in platelet antibody titer associated with a concomitant rise in platelet count. Statistical analysis of sequential platelet counts revealed an increase with plasmapheresis and immunosuppression that was significantly greater than that achieved with immunosuppression alone (p less than 0.005).

Adolescent↗

Hematuria after renal allograft biopsy: treatment with aminocaproic acid.

Aminocaproic acid (EACA) was used in 2 patients with cadaveric renal allografts because gross hematuria developed after percutaneous renal biopsies. Marked improvement was noted within twelve hours with no recurrence after discontinuation of EACA. EACA was effective in moderate renal failure.

Adolescent↗

Vancomycin prevents polytetrafluoroethylene graft infections in pediatric patients receiving chronic hemodialysis.

Polytetrafluoroethylene (PTFE) grafts have been a useful addition to the pediatric hemodialysis vascular access armamentarium. In this study, 17 pediatric patients underwent 331 total months of hemodialysis via PTFE grafts. There was a statistically significant (P less than .025) decrease in the incidence of graft infections in 12 patients (235 patient-months) while receiving prophylactic parenteral vancomycin compared with 9 patients (96 patient-months) while receiving no vancomycin (0% v 44%). Vancomycin side effects were uncommon and mild. Vancomycin is a safe and effective agent for the prevention of PTFE graft infections in pediatric patients receiving chronic hemodialysis.

Adolescent↗

Urinothorax as a manifestation of nondilated obstructive uropathy following renal transplantation.

A 12-year-old patient developed prolonged nondilated urinary obstruction and pleural effusion shortly after undergoing renal transplantation. Renal sonography, angiography, and isotope renography failed to identify an obstructive process. On the 18th postoperative day, pleural effusion was noted in the right hemithorax, and by day 24, increased perinephric fluid was observed on renal scan. Following a nephrostomy, the pleural effusion resolved and renal function improved remarkably. A ureterovesical junction obstruction and renal pelvis tear that were later discovered were repaired. Whenever a ureteral obstruction is suspected the diagnosis should be pursued vigorously, despite normal radiologic findings, especially in the presence of pleural effusion. Consideration of the possibility of urinothorax in such cases may obviate the need for lung biopsy.

Child↗

Nephritis associated with an infected peritoneovenous LeVeen shunt.

A patient with chronic active hepatitis and medically unmanageable ascites developed staphylococcal bacteremia after insertion of a peritoneovenous LeVeen shunt. The patient developed glomerulonephritis, manifested by moderate proteinuria, microscopic hematuria with red cell casts, azotemia, and evidence of complement activation. The protracted infection, urinary, and renal abnormalities subsided after removal of the LeVeen shunt and a 3-week course of antibiotics. The clinical course of this patient is typical of the immune-complex mediated glomerulonephritis that has been previously well described in hydrocephalic patients with chronically infected ventriculoatrial shunts.

Ascites↗

The role of ambulatory blood pressure monitoring in the evaluation of adolescent hypertension.

We performed 24-hour ambulatory blood pressure monitoring in a group of adolescents with hypertension induced by dynamic exercise and a group of normotensive controls. Ambulatory blood pressure monitoring was performed using a Del-Mar Avionics PIII recorder with readings taken every 7 1/2 minutes. There was little inter-individual variation in mean hourly blood pressure and the difference between mean hourly readings was not significant in hypertensives. Mean 24-hour ambulatory blood pressure was 130.2/80.7 mmHg for hypertensives and 115.2/70.8 in normotensives. Mean 24-hour variability was 18.3/12.9 mmHg in hypertensives and 14.6/11.5 in normotensives. There was no significant change in blood pressure or variability between day-time and evening for hypertensives. Normotensives showed a significant reduction in both BP and variability compared to hypertensives. In adolescents with systolic hypertension, ambulatory blood pressure monitoring confirmed a failure to reduce blood pressure following routine activity. This technique maybe used as a predictive marker of early, adult essential hypertension.

Adolescent↗