Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 24
Filter
1.
Minerva Pediatr ; 67(1): 99-104, 2015 Feb.
Article in Italian | MEDLINE | ID: mdl-25602749

ABSTRACT

As a result of advances in treatment, almost 90% of children diagnosed with Wilms tumor became long-term survivors, and have a sustainable quality of life. These patients' involvement in sports during their childhood is hopefully increasing too. The cornerstone of renal tumor cure remains radical nephrectomy, however, so survivors live with a solitary kidney. In most European countries and the USA, the involvement in sports of children with a solitary kidney depends on a responsible physician saying a "qualified yes", pending individual assessment. Unlike the case in the rest of Europe, in Italy having only one kidney automatically disqualifies an individual wishing to participate in any organized "competitive" sports carrying some risk of renal trauma, including basketball, soccer and sometime volleyball. This absolute restriction is based on ad hoc Ministerial rulings concerning "Health protection in sport activities". But available data do not seem to support such an absolute limitation on participation in sports based exclusively on the fact of having a single kidney. The sport-specific incidence of kidney injuries has been estimated at 2.3 injuries per million male athlete/exposures for basketball (2.5 for females), and 2.6 for soccer (6.0 for girls). Kidney injuries are significantly more rare than head or spine injuries. This article aims to provide Italian sport medicine specialists and policy-makers with the necessary background so that the current, over-protective "unquestionably no" response can be reconsidered, and converted into a still well-founded, more permissive attitude to the sports activities suitable for any children with a solitary normal kidney.


Subject(s)
Athletic Injuries/epidemiology , Kidney/injuries , Sports , Adolescent , Child , Europe , Female , Humans , Incidence , Italy , Kidney Neoplasms/surgery , Male , Nephrectomy , Quality of Life , Sports Medicine , Survivors , Wilms Tumor/surgery
3.
Transfus Apher Sci ; 51(2): 134-6, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25294113

ABSTRACT

The atypical HUS (aHUS) is a rare genetic disease, with poor prognosis, characterized by microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. This syndrome is often related to mutations in the genes encoding complement regulatory proteins. A 26-year-old woman with homozygous mutation in complement factor H (CFH) developed a relapse of aHUS at 17th week of pregnancy. Despite treatment with plasma exchange (PEX), at the 26th week of gestation eculizumab was started. The sequential treatment with eculizumab after PEX was well tolerated and it has led to clinical remission.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Atypical Hemolytic Uremic Syndrome/therapy , Genetic Diseases, Inborn/therapy , Plasma Exchange , Pregnancy Complications, Hematologic/therapy , Atypical Hemolytic Uremic Syndrome/genetics , Complement Factor H/genetics , Female , Genetic Diseases, Inborn/genetics , Homozygote , Humans , Mutation , Pregnancy , Pregnancy Complications, Hematologic/genetics
4.
J Thromb Haemost ; 12(9): 1440-8, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24853860

ABSTRACT

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy characterized by hemolysis, platelet consumption, and renal injury. Eculizumab, a mAb that blocks complement activity, has been successfully used in aHUS. OBJECTIVES: To optimize eculizumab therapy in aHUS patients by monitoring complement functional tests and markers of disease activity. PATIENTS/METHODS: We studied 18 patients with aHUS (10 males; eight females; age range, 2-40 years) treated with eculizumab to induce and/or maintain disease remission. Patients were followed up for a cumulative observation period of 160 months, during which blood samples were obtained at various time intervals to measure complement activity (Wieslab for the classical, alternative and mannose-binding lectin complement pathways) and the parameters of disease activity (haptoglobin and lactate dehydrogenase serum levels, and platelet count). The intravenous eculizumab doses of 12-33 mg kg(-1) were initially administered every week, with the interval between doses being gradually extended to 2 weeks, 3 weeks and 4 weeks on the basis of strict laboratory and clinical control. RESULTS: Complement activity was normal before eculizumab treatment, regardless of the state of the disease (activity or remission). It was completely suppressed 1 week, 2 weeks and 3 weeks after the last eculizumab infusion (mean values ± standard deviation: 1% ± 1% to 3% ± 5% for both the classical and alternative pathways; P = 0.0001 vs. baseline), and partially suppressed after 4 weeks (22% ± 26% and 16% ± 27%; P = 0.0001 vs. baseline). The increase in the time interval between eculizumab infusions did not change disease activity markers. CONCLUSIONS: Monitoring complement tests can allow a safe reduction in the frequency of eculizumab administration in aHUS while keeping the disease in remission.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Atypical Hemolytic Uremic Syndrome/drug therapy , Complement C3/antagonists & inhibitors , Complement C5/antagonists & inhibitors , Adolescent , Adult , Atypical Hemolytic Uremic Syndrome/genetics , Blood Platelets/metabolism , Child , Child, Preschool , Complement C3/chemistry , Complement C5/chemistry , Complement Factor H/chemistry , Female , Hemolysis , Humans , Kidney Transplantation , Male , Mutation , Platelet Count , Remission Induction , Thrombotic Microangiopathies/drug therapy , Time Factors , Young Adult
5.
Am J Transplant ; 12(12): 3337-54, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22958221

ABSTRACT

Eculizumab (anti-C5) has been sporadically reported as an efficient therapy for atypical hemolytic uremic syndrome (aHUS). However, the lack of series precludes any firm conclusion about the optimal use of anti-C5 for preventing or treating aHUS posttransplant aHUS recurrence. We thoroughly studied 22 renal transplant recipients with aHUS who received off-label therapy with anti-C5, including 12 cases, which have not been reported yet. Nine patients, all carrying a complement genetic abnormality associated with a high risk of aHUS recurrence, received prophylactic anti-C5 therapy to prevent posttransplant recurrence. Eight of them had a successful recurrence-free posttransplant course and achieved a satisfactory graft function, while the remaining patient experienced early arterial thrombosis of the graft. Thirteen renal transplant recipients were given anti-C5 for posttransplant aHUS recurrence. A complete reversal of aHUS activity was obtained in all of them. Importantly, the delay of anti-C5 initiation after the onset of the aHUS episode inversely correlated with the degree of renal function improvement. Three patients in whom anti-C5 was subsequently stopped experienced a relapse. Altogether these data suggest that long-term eculizumab is highly effective for preventing and treating posttransplant aHUS recurrence. Our study also indicates that anti-C5 should be promptly started if a recurrence occurs.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Hemolytic-Uremic Syndrome/drug therapy , Kidney Transplantation/adverse effects , Postoperative Complications , Secondary Prevention , Adolescent , Adult , Atypical Hemolytic Uremic Syndrome , Child , Child, Preschool , Complement C5/antagonists & inhibitors , Complement C5/immunology , Female , Hemolytic-Uremic Syndrome/etiology , Humans , Infant , Male , Prognosis , Retrospective Studies , Young Adult
6.
Pediatr Med Chir ; 34(5): 234-6, 2012.
Article in Italian | MEDLINE | ID: mdl-23342748

ABSTRACT

We describe a case of nephrotic syndrome (NS) after a 7 months treatment with D-penicillamine in a 14 years old girl with Wilson's disease, with a prompt regression at the discontinuation of the drug. Kidney function, proteinuria in particular, must be always monitored during the chelating therapy, and the drug must be discontinued as soon as signs of renal injury are detected.


Subject(s)
Chelating Agents/adverse effects , Hepatolenticular Degeneration/complications , Nephrotic Syndrome/chemically induced , Penicillamine/adverse effects , Adolescent , Chelating Agents/administration & dosage , Female , Hepatolenticular Degeneration/drug therapy , Humans , Penicillamine/administration & dosage , Time Factors , Treatment Outcome , Zinc Acetate/administration & dosage
7.
G Ital Nefrol ; 23(2): 149-62, 2006.
Article in Italian | MEDLINE | ID: mdl-16710820

ABSTRACT

Arterial hypertension (AH), either primary or secondary, is an important issue in childhood for its short- and long-term cardiovascular morbidity. Renal diseases are the most frequent causes of AH in children, but essential hypertension can also be detected early in life. It is important for blood pressure (BP) to be checked regularly (at least once every 5 years) in healthy children and adolescents and every year in those belonging to at-risk categories (family history of AH, low birth weight, obesity, etc). In children, AH is defined as BP recorded in three non-consecutive measurements with an appropriate device and cuff size > or = 95th centile for age, gender and height. Ambulatory BP monitoring is a valuable diagnostic tool and once AH is confirmed, a specific primary cause should always be ruled out (renovascular, cardiac, vascular, endocrine, pharmacologic, other). In case of border-line or significant AH (between 90th and 99th centile) a non-pharmacological treatment should be considered, whereas severe hypertension (>99th centile for height and age) will require pharmacological treatment (Diuretics, Angiotensin Converting Enzyme Inhibitors, Angiotensin Receptor Blockers, beta - and Calcium blockers).


Subject(s)
Hypertension/diagnosis , Hypertension/drug therapy , Child , Female , Heart Diseases/etiology , Humans , Hypertension/complications , Hypertension/etiology , Kidney Diseases/complications , Male
11.
Pediatr Nephrol ; 16(10): 773-6, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11605779

ABSTRACT

Like cyclosporine (CsA), tacrolimus acts through the inhibition of renal phosphatase calcineurin. CsA induces reversible vasoconstriction, causing a transient reduction of renal plasma flow in patients with renal transplantation. The aim of this study was to determine the effect of tacrolimus on renal plasma flow in renal transplanted children. Eight children were studied with a median age of 10.6 years, a mean glomerular filtration rate (inulin clearance) of 55 ml/min per 1.73 m2 (range 29-95), and a mean follow-up after transplantation of 5.6 months. Effective renal plasma flow (ERPF) was studied in each patient for 12 h after tacrolimus administration. Clearances were obtained every 2 h for 12 h after drug administration. Tacrolimus pharmacokinetics was also studied. Average ERPF at the start of the test was 289 ml/min per 1.73 m2 (range 177-404, SD +/- 106). Variation in each of the 2-h periods was not significant, although a mild reduction of plasma flow was observed in three of the eight children. No correlation was found between tacrolimus AUC, peak, or trough levels and renal blood flow variations. Despite the relatively small number of patients studied, these data suggest that, in vivo, a therapeutic oral dose of tacrolimus is not necessarily followed by a significant reduction of ERPF in renal transplanted children.


Subject(s)
Immunosuppressive Agents/adverse effects , Kidney Transplantation/physiology , Renal Circulation/drug effects , Tacrolimus/adverse effects , Adolescent , Area Under Curve , Child , Female , Humans , Immunosuppressive Agents/pharmacokinetics , Kidney Function Tests , Male , Tacrolimus/pharmacokinetics , Transplantation, Homologous , p-Aminohippuric Acid/metabolism
12.
Clin Nephrol ; 55(6): 453-9, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11434356

ABSTRACT

AIMS: L-arginine (LA), the precursor of nitric oxide (NO), was suggested to be beneficial in many forms of renal disease: hypertension, ureteral obstructive nephropathy and cyclosporin A (CsA) nephrotoxicity. METHODS: Thus, we investigated the effects of LA supplementation on renal function, proteinuria and blood pressure (BP) in young renal allograft recipients with chronic renal transplant dysfunction treated with CsA. Eleven CsA-treated renal allograft recipients with chronic transplant dysfunction, aged 11-22 years, were randomly assigned to a 6-week treatment period with placebo (P), followed by 2 subsequent 6-week periods with LA supplementation (0.1 g/kg body weight/day) or a 6-week treatment period with LA, followed by 2 subsequent 6-week periods with P. At the end of each treatment period 24-hour BP recordings were made, and GFR (Inutest), RPF (PAH clearance) and the urinary excretion of protein, albumin, nitrate, cGMP and urea were evaluated. RESULTS: In comparison to placebo, LA treatment did not significantly change GFR, RPF, proteinuria and albuminuria, mean systolic or diastolic BP. The urinary excretion of urea and NO3 increased after LA supplementation (uUrea: LA 26.3 +/- 4.6 compared to P 23.5 +/- 4.7 g/day/1.73 m3, p < 0.05, uNO3: LA 514 +/- 152 compared to P 95 +/- 41 mM/day/1.73 m3, p < 0.05), whereas urinary excretion of cGMP remained unchanged. CONCLUSION: LA supplementation did not improve renal function and did not decrease proteinuria in CsA-treated renal allograft recipients with chronic transplant dysfunction possibly because of inhibition of NO-cGMP forming mechanism.


Subject(s)
Arginine/therapeutic use , Kidney Transplantation/physiology , Adolescent , Child , Cyclosporine/therapeutic use , Double-Blind Method , Female , Follow-Up Studies , Humans , Immunosuppressive Agents/therapeutic use , Male , Time Factors
13.
Perit Dial Int ; 21(2): 172-9, 2001.
Article in English | MEDLINE | ID: mdl-11330562

ABSTRACT

OBJECTIVE: To evaluate the sensitivity of anthropometry and bioelectrical impedance analysis (BIA) in detecting alterations in body composition of children treated with peritoneal dialysis (PD), and to determine the prevalence of malnutrition in this population, in short- and long-term PD duration, using anthropometric and BIA-derived indices. PATIENTS: Eighteen children treated with automated PD (11 males, 7 females; mean age 8.7 +/- 4.7 years). DESIGN: Eighteen patients were studied using anthropometry and BIA at the start (t0) and after 6 months (t1) of PD, 15 of these patients at 12 months (t2), and 8 at 24 months (t3) of PD. Midarm muscle circumference (MAMC), arm muscle area (AMA), and arm fat area (AFA) were calculated from anthropometric measures according to Frisancho (FrisanchoAR. New norms of upper limb fat and muscle areas for assessment of nutritional status. Am J Clin Nutr 1981; 34:2540-5.). The bioelectrical measures of resistance (R) and reactance (Xc) were obtained directly from the impedance signal; phase angle (PA) and distance (D) were calculated using mathematical formulas. Nutritional status was assessed by anthropometric measurements and BIA-derived indices, expressed as standard deviation scores (SDS), and by a score system based on BIA and anthropometric parameters. The percentage of children with values of anthropometric and BIA-derived indices below the 3rd percentile or between the 3rd and 25th percentiles, and the percentage of children with scores of 7-12 and 4-6 were calculated in order to detect patients with severe or moderate derangement of nutritional status. RESULTS: The mean SDS values of Xc, PA, and D significantly improved (p = 0.05, p = 0.001, p = 0.02) during the first 6 months of PD and remained almost stable during the following months. The SDS values of the anthropometric indices were less compromised than those of the BIA-derived indices, particularly at the start of dialysis. By 6 months, the percentages of children with values of BIA and anthropometric indices below the 3rd percentile had decreased. The percentages of patients with moderate and severe derangement of BIA and anthropometric indices remained substantially unchanged after 12 months. However, at 24 months, the percentage of patients with moderate derangement of BIA indices increased. All these findings were confirmed by the nutritional score system. CONCLUSION: BIA is more sensitive than anthropometry in detecting alterations in body composition of children on PD. The prevalence of malnutrition, high at the commencement of PD, decreases during the first year of treatment but not over the long term.


Subject(s)
Anthropometry , Body Composition , Nutrition Disorders/diagnosis , Peritoneal Dialysis/adverse effects , Adolescent , Child , Child, Preschool , Electric Impedance , Female , Humans , Infant , Male , Nutrition Disorders/etiology , Nutritional Status , Sensitivity and Specificity
14.
Kidney Int ; 58(3): 981-8, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10972662

ABSTRACT

BACKGROUND: Oral and intravenous calcitriol bolus therapy are both recommended for the treatment of secondary hyperparathyroidism, but it has been claimed that the latter is less likely to induce absorptive hypercalcemia. The present study was undertaken to verify whether intravenous calcitriol actually stimulates intestinal calcium absorption less than oral calcitriol and whether it is superior in suppressing parathyroid hormone (PTH) secretion. METHODS: Twenty children (16 males, age range of 5.1 to 16.9 years, mean creatinine clearance 21.9 +/- 11.5 mL/min/1.73 m2, range of 7.4 to 52.7) with chronic renal failure (CRF) and secondary hyperparathyroidism [median intact PTH (iPTH), 327 pg/mL; range 143 to 1323] received two single calcitriol boli (1.5 mg/m2 body surface area) orally and intravenously using a randomized crossover design. iPTH and 1,25(OH)2D3 levels were measured over 72 hours, and intestinal calcium absorption was measured 24 hours after the calcitriol bolus using stable strontium (Sr) as a surrogate marker. Baseline control values for Sr absorption were obtained in a separate group of children with CRF of similar severity. RESULTS: The peak serum level of 1,25(OH)2D3 and area under the curve baseline to 72 hours (AUC0-72h) were significantly higher after intravenous (IV) calcitriol (AUC0-72h oral, 1399 +/- 979 pg/mL. hour vs. IV 2793 +/- 1102 pg/mL. hour, P < 0.01), but the mean intestinal Sr absorption was not different [SrAUC0-240min during the 4 hours after Sr administration 2867 +/- 1101 FAD% (fraction of the absorbed dose) vs. 3117 +/- 1581 FAD% with oral and IV calcitriol, respectively]. The calcitriol-stimulated Sr absorption was more then 30% higher compared with control values (2165 +/- 176 FAD%). A significant decrease in plasma iPTH was noted 12 hours after the administration of the calcitriol bolus, which was maintained for up to 72 hours without any differences regarding the two routes of administration. CONCLUSIONS: These results demonstrate that under acute conditions, intravenous and oral calcitriol boli equally stimulate calcium absorption and had a similar efficacy in suppressing PTH secretion.


Subject(s)
Calcitriol/administration & dosage , Calcium Channel Agonists/administration & dosage , Hyperparathyroidism, Secondary/drug therapy , Hyperparathyroidism, Secondary/metabolism , Intestinal Absorption/drug effects , Strontium/pharmacokinetics , Administration, Oral , Adolescent , Calcitriol/blood , Calcium/blood , Calcium/pharmacokinetics , Calcium Channel Agonists/blood , Child , Child, Preschool , Creatinine/blood , Female , Humans , Hypercalcemia/drug therapy , Hypercalcemia/etiology , Hypercalcemia/metabolism , Hyperparathyroidism, Secondary/etiology , Injections, Intravenous , Kidney Failure, Chronic/complications , Male , Parathyroid Hormone/blood , Phosphates/blood
15.
Pediatr Nephrol ; 14(7): 664-8, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10912539

ABSTRACT

Calcitriol oral pulse therapy has been suggested as the treatment of choice for secondary hyperparathyroidism, but its efficacy and safety are still under discussion. The present randomized multicenter study compares the effect of an 8-week course of daily versus intermittent (twice weekly) calcitriol therapy on parathyroid hormone (PTH) suppression in 59 children (mean age 8.4+/-4.7 years) with chronic renal insufficiency (mean Ccr 22.4+/-11.6 ml/min per 1.73 m2) and secondary hyperparathyroidism. After a 3-week washout period, the patients were randomly assigned to treatment with daily oral calcitriol (10 ng/kg per day) or intermittent oral calcitriol (35 ng/kg given twice a week). The calcitriol dose was not changed throughout the study period of 8 weeks. At start of the study, the median intact PTH (iPTH) level was 485 pg/ml (range 83-2032) in the daily group (n=29) and 315 pg/ml (range 93-1638) in the intermittent group (n=30). After 8 weeks, the respective median iPTH concentrations were 232 pg/ml (range 63-1614) and 218 pg/ml (range 2-1785) (ns). The mean iPTH decrease from baseline was 19.2+/-57.8% and 13.7+/-46.7% respectively (not significant). Calcitriol reduced the iPTH concentration in 23/29 patients in the daily group and in 21/30 in the intermittent group. One episode of hypercalcemia (>11.5 mg/dl) was observed in both groups and a single episode of hyperphosphatemia (>7.5 mg/dl) was observed in the daily group. It is concluded that oral calcitriol pulse therapy does not control secondary hyperparathyroidism more effectively than the daily administration of calcitriol in children with chronic renal failure prior to dialysis.


Subject(s)
Acute Kidney Injury/complications , Calcitriol/administration & dosage , Calcium Channel Agonists/administration & dosage , Hyperparathyroidism, Secondary/drug therapy , Hyperparathyroidism, Secondary/etiology , Administration, Oral , Adolescent , Calcitriol/therapeutic use , Calcium Channel Agonists/therapeutic use , Child , Child, Preschool , Drug Administration Schedule , Female , Humans , Hyperparathyroidism, Secondary/blood , Male , Parathyroid Hormone/blood , Prospective Studies
16.
J Bone Miner Res ; 14(10): 1789-95, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10491227

ABSTRACT

It has been suggested that 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) stimulates intestinal calcium absorption less via the intravenous (iv) than the oral route, because the first avoids direct contact of the drug with the enterocytes. However, no study has addressed the issue directly. This investigation was designed to measure the effect of a single oral or iv dose of 1,25(OH)2D3 on calcium absorption, using stable strontium (Sr) as a surrogate for calcium, and measuring the Sr fractional absorbed dose (FAD%) over 240 minutes after Sr administration. In 10 healthy volunteers, five tests were performed in a cross-over design, with a wash-out period between two consecutive tests: Sr absorption without 1,25(OH)2D3 (test A); Sr absorption immediately after either oral (test B) or iv (test C) 1,25(OH)2D3 (1.5 microg/m2 of body surface area [BSA]); Sr absorption (24 hr after either oral (test D) or iv (test E) 1, 25(OH)2D3 (1.5 microg/m2 BSA). The concurrent administration of 1, 25(OH)2D3 and Sr (tests B and C) did not significantly change the area under the Sr FAD%-time curve with respect to test A (test A: 4090 +/- 345; test B: 4510 +/- 345; test C: 4210 +/- 345), whereas Sr absorption was significantly increased (p < 0.001) when Sr was given 24 hr after either oral or iv 1,25(OH)2D3 (test D: 5710 +/- 345; test E: 5510 +/- 345). It was concluded that 1,25(OH)2D3 is likely to influence calcium absorption significantly only via its genomic effect, independent of its administration route.


Subject(s)
Calcitriol/therapeutic use , Intestinal Absorption , Strontium/pharmacokinetics , Administration, Oral , Adult , Cross-Over Studies , Female , Humans , Injections, Intravenous , Male , Reference Values
17.
Clin Nephrol ; 52(1): 37-43, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10442494

ABSTRACT

AIM AND METHODS: In order to investigate the role of kidney damage on renal response to L-arginine (L-Arg) infusion in transplant patients receiving cyclosporine A (CsA) treatment, we assessed systemic and glomerular hemodynamic variables, the fraction excretion of urinary sodium, albumin, cyclic GMP (as an index of nitric oxide (NO) production from L-Arg) and urea excretion (as an index of ureagenesis), and glucoregulatory hormone levels in five normal volunteers and 21 renal allograft recipients (aged 10-20 years) treated with CsA, 10 with normal renal function and 11 with chronic renal insufficiency. RESULTS: In the normal subjects, L-Arg infusion (290 mg/min/1.73 m2 for 1 h) significantly reduced mean arterial pressure (MAP) (76+/-7 to 70+/-5 mmHg) and renal vascular resistance (RVR), and increased GFR (103+/-9 to 122+/-7 min/1.73 m2), RPF, urinary cyclic GMP excretion (0.40+/-0.1 to 0.60+/-0.1 nmol/100 ml glomerular filtrate (GF)), and sodium and albumin excretion. Neither the patients with chronic graft dysfunction nor those with a normal graft responded to L-Arg infusion: RVR remained high, and MAP, GFR, RPF, fractional excretion of sodium and urinary excretion of albumin and cyclic GMP were unchanged in both groups of patients. Glucagon, insulin and urinary urea excretion rose significantly in controls and both patient groups. CONCLUSION: The hemodynamic effects of L-Arg infusion were inhibited in the patients, regardless of their degree of renal function, possibly because L-Arg-NO production was blunted.


Subject(s)
Arginine/pharmacology , Hemodynamics/drug effects , Kidney Transplantation/physiology , Adolescent , Adult , Arginine/administration & dosage , Child , Cyclic GMP/biosynthesis , Cyclosporine/therapeutic use , Female , Glomerular Filtration Rate/drug effects , Graft Rejection/drug therapy , Graft Rejection/metabolism , Graft Rejection/physiopathology , Humans , Immunosuppressive Agents/therapeutic use , Infusions, Intravenous , Male , Reference Values , Sodium/urine , Vascular Resistance/drug effects , p-Aminohippuric Acid/urine
18.
Am J Physiol ; 276(1): F137-42, 1999 01.
Article in English | MEDLINE | ID: mdl-9887089

ABSTRACT

We investigated the effects of hypotonic saline-induced modifications of extracellular volume and sodium handling on the renal and metabolic response to amino acids (AA). Renal hemodynamics (Inutest, p-aminohippurate clearance), plasma AA, and glucagon levels, as well as urea and sodium excretion, were studied in seven adult volunteers infused for 2 h, on six separate occasions, according to the following protocols: 1) high-AA solution (300 mg. min-1. 1.73 m-2); 2) low-AA solution (150 mg. min-1. 1.73 m-2); 3) low AA + 2,000 ml/1.73 m2 of 0.23% saline solution; 4) high AA + 0. 23% saline; 5) high AA + 0.45% saline; and 6) 0.45% saline alone. The glomerular filtration rate (GFR) rise induced by the high-AA solution was similar to that induced by the low-AA solution (DeltaGFR = +24 +/- 6 and +20.2 +/- 7 ml. min-1. 1.73 m-2, respectively), whereas the plasma AA and glucagon levels and urea excretion rate increases were related to AA dose. The addition of 0. 23% saline to the low-AA solution and of 0.45% saline to the high-AA solution blunted the renal hemodynamic response (DeltaGFR = +6.6 +/- 10.1 and +11.4 +/- 8.3 ml. min-1. 1.73 m-2, respectively) without modifying the pattern of plasma AA and glucagon levels and urea excretion observed with the AA infusion alone. Urinary sodium excretion increased from baseline with each protocol and rose even further when saline was added to AA. A negative correlation (r = -0. 38, P < 0.05) was found between the changes from basal values in GFR and those in sodium excretion rate with high-AA infusion at different levels of sodium concentration. These data suggest that AA-induced hyperfiltration might be blunted by hypotonic saline infusion, possibly through an acute modification of renal sodium handling and extracellular volume.


Subject(s)
Amino Acids/pharmacology , Kidney/drug effects , Sodium Chloride/pharmacology , Adult , Amino Acids/blood , Diuresis/drug effects , Dose-Response Relationship, Drug , Glomerular Filtration Rate/drug effects , Glucagon/blood , Hemodynamics/drug effects , Humans , Male , Metabolism/drug effects , Natriuresis/drug effects , Renal Circulation/drug effects
19.
Am J Nephrol ; 18(5): 359-66, 1998.
Article in English | MEDLINE | ID: mdl-9730557

ABSTRACT

In order to investigate the renal effects of amino acids (AA) with different metabolic fate, we compared the changes in glomerular and tubular function, nitrogen metabolism and glucoregulatory hormones in 7 volunteers during two infusions, one of a complete solution of amino acids (MIX-AA), which included five AA electively metabolized at the splanchnic level, and the other of a solution containing only essential AA (EAA), which escape splanchnic metabolism. MIX-AA increased GFR and RPF (from 104 +/- 6 to 122 +/- 13 and from 488 +/- 46 to 572 +/- 34 ml/min/1.73 m2), stimulated splanchnic metabolism as demonstrated by rises in urinary urea excretion (from 20.7 +/- 2 to 30.6 +/- 7.5 mg/min/1.73 m2) and the plasma glucagon/insulin ratio (from 21.4 +/- 13 to 26.7 +/- 15), and caused increases in fractional excretion of AA, FeNa and free-water clearance. During MIX-AA infusion significant correlations were observed between the individual values of GFR and the urea excretion rate (r = 0.66), and between GFR modifications (DeltaGFR) and the plasma glucagon/plasma insulin ratio (r = 0.40). No change in renal function, urea excretion and the glucagon/insulin ratio was observed with EAA. An intermediate splanchnic step (increased plasma glucagon/insulin ratio and ureagenesis) seems necessary in the pathway leading to the nonessential AA-induced rise in GFR; this might stimulate an ultimate intrarenal pathway (possibly involving the diluting segment) via a still undefined mechanism.


Subject(s)
Amino Acids/administration & dosage , Kidney/physiology , Adult , Amino Acids/metabolism , Amino Acids/pharmacology , Amino Acids, Essential/administration & dosage , Amino Acids, Essential/metabolism , Amino Acids, Essential/pharmacology , Glomerular Filtration Rate/drug effects , Glucagon/blood , Humans , Infusions, Intravenous , Insulin/blood , Kidney/drug effects , Male , Osmolar Concentration , Renal Plasma Flow/drug effects , Urea/blood , Viscera/metabolism
20.
Perit Dial Int ; 18(1): 71-4, 1998.
Article in English | MEDLINE | ID: mdl-9527033

ABSTRACT

OBJECTIVE: To analyze the data from 347 peritoneal catheters implanted in 249 pediatric patients aged < or = 15 years at start of chronic peritoneal dialysis (CPD). DESIGN: Restrospective study of the data collected between 1986 and 1995, in 20 dialysis centers, from the Italian Registry of Pediatric Chronic Peritoneal Dialysis. Data collection for each pediatric catheter included: catheter type, site and technique of insertion, complications, duration, and reason for removal or replacement. RESULTS: Fifty catheters were inserted in patients under 2 years of age, 50 in patients aged 2 - 5 years and 247 in patients over 5 years of age. Catheter types included 307 (88.5%) Tenckhoff (286 double cuff, 21 single cuff) and 40 (11.5%), double-cuff, Valli-type catheters. All catheters were surgically implanted and omentectomy was performed in 83.5% of cases; the entry-site was in the midline in 136 cases (39.2%) and paramedian in 211 (60.8%). During 6076 CPD months we observed 274 catheter-related complications: 182 catheter infections (exit-site and/or tunnel infection), 23 leakages, 19 obstructions, 19 cuff-extrusions, 14 dislocations, 6 hemoperitoneum, 10 other (incidence of one complication every 21.8 dialysis-months). A significant reduction of catheter-related complications occurred in the last five years, compared with the first 5 years. One hundred and six catheters were removed due to catheter-related causes: infection (83 cases), obstruction (11), dislocation (4), outer-cuff extrusion (3), leakage (2), bowel incarceration (2), and bowel infarction (1). Catheter survival was 72.2% at 12 months, 52.3% at 24 months, 32.8% at 36 months, and 25.7% at 48 months. Significantly lower catheter survival was found in younger children (0 - 2 years) compared with two other age groups (2 - 5 years, and > 5 years). No significant correlation was found between catheter survival and catheter entry-site (midline vs paramedian). CONCLUSIONS: Catheter-related infections were confirmed to be the most common complication and most frequent cause of peritoneal catheter removal. In addition, catheter survival rate was worse in younger children, indicating that more effort should be made to improve peritoneal catheter survival particularly in this age group.


Subject(s)
Catheters, Indwelling/adverse effects , Peritoneal Dialysis, Continuous Ambulatory/instrumentation , Adolescent , Child , Child, Preschool , Humans , Infant , Italy , Registries , Retrospective Studies , Treatment Outcome
SELECTION OF CITATIONS
SEARCH DETAIL
...