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Biomedical subjects

P Alessandrini

Publications and source records attributed to P Alessandrini.

At least 37 records · Page 2Linked to original sources
PubMed1997

In vivo formation of 8-Epi-prostaglandin F2 alpha is increased in hypercholesterolemia.

F2-isoprostanes are bioactive prostaglandin (PG)-like compounds that are produced from arachidonic acid through a nonenzymatic process of lipid peroxidation catalyzed by oxygen free-radicals. 8-Epi-PGF2 alpha may amplify the platelet response to agonists, circulates in plasma, and is excreted in urine. We examined the hypothesis that the formation of 8-epi-PGF2 alpha is altered in patients with hypercholesterolemia and contributes to platelet activation in this setting. Urine samples were obtained from 40 hypercholesterolemic patients and 40 age- and sex-matched control subjects for measurement of immunoreactive 8-epi-PGF2 alpha. Urinary excretion of 11-dehydro-thromboxane (TX) B2, a major metabolite of TXA2, was measured as an in vivo index of platelet activation. Low-dose aspirin, indobufen, and vitamin E were used to investigate the mechanism of formation and effects of 8-epi-PGF2 alpha on platelet activation. Urinary 8-epi-PGF2 alpha was significantly (P = .0001) higher in hypercholesterolemic patients than in control subjects: 473 +/- 305 versus 205 +/- 95 pg/mg creatinine. Its rate of excretion was inversely related to the vitamin E content of LDL and showed a positive correlation with urinary 11-dehydro-TXB2. Urinary 8-epi-PGF2 alpha was unchanged after 2-week dosing with aspirin and indobufen despite complete suppression of TX metabolite excretion. Vitamin E supplementation was associated with dose-dependent reductions in both urinary 8-epi-PGF2 alpha and 11-dehydro-TXB2 by 34% to 36% and 47% to 58% at 100 and 600 mg daily, respectively. We conclude that the in vivo formation of the F2-isoprostane 8-epi-PGF2 alpha is enhanced in the vast majority of patients with hypercholesterolemia. This provides an aspirin-insensitive mechanism possibly linking lipid peroxidation to amplification of platelet activation in the setting of hypercholesterolemia. Dose-dependent suppression of enhanced 8-epi-PGF2 alpha formation by vitamin E supplementation may contribute to the beneficial effects of antioxidant treatment.

Antioxidants↗
PubMed1996

[Closed traumas of the kidney in children. Conservative treatment].

Therapeutic approach to 36 children with blunt trauma of the kidney is reported. Generally, conservative attitude was applied. In case of type II or type III lesions, according to the Hodges classification, or when a urohematoma does not regress or worsens, we propose endoscopic drainage to avoid complications. Seventy percent of the patients, seen 2 years after the trauma, were free of complications. These patients will be reassessed again, many years after the initial trauma in order to determine the long-term results of this conservative attitude.

Child↗
PubMed1994

Dynamic liver radionuclide scanning in the evaluation of liver failure and portal hypertension in cirrhotic patients.

Dynamic liver radionuclide scanning was performed in cirrhotic patients to correlate three parameters derived by this technique to the severity of liver function impairment and clinical-endoscopic signs of portal hypertension. We found a close association between the severity of liver failure (Child-Pugh criteria) and both the relative blood flow (p < 0.05) and the shape (shifting to the left) of the early flow curve (p < 0.01). A significant association between the presence of portal hypertension and shifting to the left of the flow curve was demonstrated in all cases in which tense ascites was associated with varices (p < 0.05). Finally, a statistically significant association (p < 0.05) was found between the degree of esophageal varices (Beppu's criteria) and the liver-to-spleen uptake ratio. These data suggest that dynamic isotope liver scanning could be an important tool in the diagnostic evaluation of liver function impairment and portal hypertension.

Aged↗
PubMed1993

[Adenocarcinoma of the kidney in children. Apropos of 2 cases with 8 and 17 years of follow-up].

The authors report on two cases of renal cell carcinoma in boys of 8 and 13 years of age revealed by gross hematuria. Following nephrectomy the evolution remains good after 8 and 17 years of follow-up. Despite the fact that renal cell carcinoma is rare in children, it must be evoked as a possible etiology in the presence of spontaneous and relapsing hematuria in a child older than 8 years of age. Early nephro-ureterectomy with regional lymph nodes resection is the only efficient treatment, chemotherapy and radiotherapy having not yet demonstrated their efficiency.

Adenocarcinoma↗
PubMed1993

[Parathyroid adenoma in a child].

We report the case of a 13 year-old white teenager who was referred for chronic bone pain. Physical examination showed a swelling of the anterior part of the neck and biological findings clearly evoked a primary hyperparathyroidism. The surgical treatment was successful and confirmed the diagnosis of parathyroid adenoma. Primary hyperparathyroidism being unusual in childhood, the eventuality of a multiple endocrine neoplasia is discussed.

Adenoma↗
PubMed1993

Effect of selective inhibition of thromboxane synthesis on renal function in diabetic nephropathy.

Studies of nondiabetic renal disease suggest that thromboxane may be an important mediator of abnormal renal function. The role of thromboxane in diabetic nephropathy is not fully understood. We measured in a double-blind, randomized, placebo-controlled crossover study the effect of a thromboxane synthase inhibitor (FCE 22178, 400 mg two or three times per day) on urinary excretion of thromboxane B2 and 6-keto-prostaglandin F1 alpha, glomerular filtration rate (measured as clearance of polyfructosan), effective renal plasma flow (clearance of para-aminohippuric acid), fractional clearances of albumin and immunoglobin G and the reabsorption rate of beta 2-microglobulin in 15 patients with type 1 (insulin-dependent) diabetic nephropathy. In seven additional patients, the effect of the thromboxane synthase inhibitor given as 400 mg twice per day was compared with that of the thromboxane synthase inhibitor given as 400 mg three times per day. FCE 22178 administration caused a significant inhibition in the excretion of urinary thromboxane B2 and 2,3-dinor-thromboxane B2 compared with placebo (12.3 +/- 2.1 vs 24.6 +/- 5.1 ng/gm creatinine, p = 0.006, and 78.5 +/- 20.3 vs 335.5 +/- 84.1 ng/gm creatinine, p = 0.004, respectively) without any compensatory increase of 6-keto- prostaglandin F1 alpha or 2,3-dinor-6-keto-prostaglandin F1 alpha that reflect prostacyclin I2 biosynthesis. Glomerular filtration rate, effective renal plasma flow, renal vascular resistance, and filtration fraction were not significantly different after placebo or thromboxane synthase inhibitor treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Blind-ending bifid ureters--report of five pediatric cases.

We report 5 cases of blind-ending ureters according to Culp's criteria. Occurrence of vesicoureteral reflux allowed us to make the diagnosis of retrograde cystography in all our patients. We wish to emphasize that this procedure must be done as the first step of urinary tract examination in children.

Child↗
PubMed1992

[Rectal angioma ruptured into the peritoneum].

The authors report on a case of rectal hemangioma ruptured into the peritoneum, successfully treated by a conservative surgical procedure. The problems associated with diagnosis and treatment are discussed.

Child, Preschool↗
PubMed1992

[Congenital umbilical fistulas. A report of 12 cases].

A brief report of 12 cases of congenital anatomical fistula (CUF) has been presented (4 cases of persistent omphalo-mesenteric, 3 persistent urachus, 4 urachal sinus, 1 persistent omphalo-mesenteric duct with urachus) with some general comments. CUF are discovered at birth or later in case of umbilical granuloma, redness, local swelling or umbilical discharge. Diagnosis and anatomical type are determined by instrumental exploration and fistulogram. Lower urinary obstruction should be eliminated in the case of persistent urachus. Complete excision is the correct treatment.

Catheterization↗
PubMed1991

Gastric duplication communicating with an aberrant pancreas.

A case of gastric duplication in connection with an aberrant pancreas in a 14 months old boy is related. The non-specificity of signs and symptoms explains why the diagnosis of these lesions has been often mislead and usually made at laparotomy. Ultrasound and technetium scan could adequately characterize these anomalies pre-operatively. Simple excision is the treatment of choice.

Gastrointestinal Hemorrhage↗
PubMed1990

Multicenter survey of endoscopic treatment of vesicoureteral reflux in children.

17 centers answered an inquiry on the endoscopic treatment of vesicoureteral reflux. 844 children were reviewed representing 1,290 ureters treated by endoscopic injection of Teflon. The first results in cases of primary or secondary reflux showed a success rate of 82.3%. All authors report low morbidity and excellent tolerance of this technique. In view of the long-term prognosis, these results should be reanalyzed, the median follow-up presently being 1 year. The next logical step should be the development of implant material with a higher biocompatibility but the identical physical properties as Teflon.

Belgium↗
PubMed1988

Thromboxane biosynthesis and platelet function in type I diabetes mellitus.

It has been speculated that platelet activation may contribute to the evolution of vascular complications in patients with Type I diabetes mellitus. To address this hypothesis, we measured the plasma and urinary metabolites of thromboxane, presumably of platelet origin, and of prostacyclin, derived from endothelial cells, in addition to more conventional indexes of platelet function. Urinary excretion of the metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1 alpha did not differ between diabetics with or without retinopathy and nondiabetic controls. Furthermore, measurement of platelet granule constituents, the aggregation responses to ADP or arachidonic acid, and levels of serum thromboxane B2 failed to discriminate between the groups. The institution of tight diabetic control with multiple daily injections of insulin failed to alter either urinary metabolite excretion or plasma levels of 11-dehydro-thromboxane B2. Conversely, insulin-induced hypoglycemia failed to alter the concentrations of plasma or urinary thromboxane metabolites in nondiabetic volunteers, despite a mean 60-fold increase in plasma epinephrine. These studies suggest that platelet activation does not precede the development of microvascular complications in patients with Type I diabetes who lack clinical evidence of macrovascular disease and have normal renal function. Furthermore, it is unlikely that platelet activation due to intermittent hypoglycemia contributes to the reportedly accelerated development of retinopathy in such patients, when they are subject to tight diabetic control.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

[Extracorporeal lithotripsy in a young child. Use of the EDAP LT 01 apparatus in a 20-month-old girl].

The possibility for treating adults with renal stone by extracorporeal shock wave lithotripsy is proved to be an effective method. However, up to now, a few cases in the world were reported in childhood, never before the patient was 3 years old; although 65% of urinary stones in children can be observed before 3 years. We report the first successful application of the EDAP lithotriptor in the management of a twenty months little girl with upper urinary stone. We conclude that this treatment must be developed in future.

Age Factors↗
PubMed1986

In vivo indexes of platelet and vascular function during fish-oil administration in patients with atherosclerosis.

Populations that consume a diet rich in marine lipids may have a lower risk of atherosclerotic disease. Fish oil contains the N-3 polyunsaturated fatty acid eicosapentaenoate, and the biosynthesis of thromboxanes and prostacyclins from eicosapentaenoate (thromboxane A3 and prostaglandin I3), rather than from the usual precursor arachidonate (thromboxane A2 and prostaglandin I2), may help to reduce the risk. To examine this hypothesis, we studied the effect of eicosapentaenoate supplementation (10 g per day) for one month on the synthesis of thromboxanes and prostacyclins, as assessed by urinary metabolite excretion, in six patients with peripheral vascular disease and seven normal controls. Supplementation markedly increased the eicosapentaenoate content of phospholipids from red cells and platelets. Synthesis of the platelet agonist thromboxane A2, which was elevated in the patients at base line, declined by 58 percent during supplementation but did not reach normal values. The decline in thromboxane A2, which is synthesized from arachidonate, coincided with the formation of the inactive thromboxane A3, which is synthesized from eicosapentaenoate. A lower dose of eicosapentaenoate (1 g per day) was not sufficient to maintain the changes in thromboxane A2 synthesis. Platelet function was only moderately inhibited during eicosapentaenoate supplementation, consistent with incomplete suppression of thromboxane A2 synthesis. These studies show that a high dose of eicosapentaenoate alters the pattern of synthesis of thromboxanes and prostacyclins. However, effects comparable to those of aspirin require long-term administration in high doses. Whether other properties of fish oil might render it a more attractive antithrombotic therapy remains to be determined.

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Physiologic variables affecting thromboxane B2 production in human whole blood.

Thrombin-induced thromboxane (TX) A2 production in whole blood, as reflected by serum TXB2 measurements, has proven to be a simple and reproducible capacity-related index of platelet TXA2 production ex vivo. In the present study we have determined the influence of a number of physiologic variables on serum TXB2 measurements performed by radioimmunoassay in a group of 177 subjects undergoing evaluation for atherosclerosis risk factors. Serum TXB2 averaged 300 +/- 108 ng/ml in the whole group, with a normal distribution. No statistically significant correlation was found between serum TXB2 and the continuous variables examined (age, BMI, blood pressure, cigarettes, serum cholesterol, triglyceride, glucose and wine consumption) except for the number of platelets. Platelet TXB2 production did not differ between men and women (296 +/- 119 vs 302 +/- 100 ng/ml). We conclude that, within the limits of the examined variables, serum TXB2 is an easily measurable and highly reproducible capacity index primarily related to platelet cyclooxygenase and TX-synthase activity, which can be used for monitoring drug- or disease-induced changes of these enzyme activities.

Adolescent↗