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We report a simple and reliable high performance liquid chromatography method for measuring creatinine in serum and urine. The chromatographic run is performed on a C(18) column after protein precipitation with acetone and addition of cimetidine as an internal standard. The separation is carried out in 20 min at a flow rate of 0.8 ml/min, with a mobile phase consisting of 100 mmol/l sodium dihydrogen phosphate solution, containing 30 mmol/l sodium lauryl sulfate pH 3.0 and acetonitrile (60:36, v/v). The absorbance is monitored at 200 nm. The relationship between creatinine concentration and the creatinine/internal standard peak area is linear up to 1,088 micromol/l. Within-run precision measured at three different creatinine concentrations ranges from 0.89% to 2.34% in serum and from 0.34% to 1.10% in urine. Between-run precision varies from 1.68% to 3.17% in serum and from 1.58% to 1.85% in urine over a wide range of concentrations. Analytical recovery is between 98.71% and 101.25% in serum and between 98.96% and 100.27% in urine. The detection limit is 3.24 micromol/l for a signal-to-noise ratio of 3. The method shows a good linearity with the reference isotope dilution gas chromatography-mass spectrometry procedure (r=0.999), without interferences, even in the presence of high bilirubin concentrations.

Tapeto-retinal degeneration is frequent in patients with nephronophthisis. Association of the most severe forms of tapeto-retinal dystrophy with NPH identifies a syndrome described first by Senior et al and Loken et al. This syndrome is distinct on molecular grounds from pure renal nephronophthisis (NPH1), which has its gene locus mapped on chromosome 2q13. We describe three families with large homozygous deletion of the NPH1 locus in which mild to moderate ocular lesions due to tapeto-retinal degeneration coexisted and were correlated to renal defects. This new association of NPH1 with retinal dystrophy is characterized by focal lesions of retina and is pauci-symptomatic in clinical presentation. For this reason it may remain unrecognized in most NPH1 patients.

Photopheresis (ECP) is a new form of photochemotherapy that induces a selective inhibition of the host response to foreign histocompatibility antigens and reverses allograft rejection after organ transplantation. This report describes four adolescent patients with recurrent rejection episodes after renal transplantation, all uncontrolled using standard protocols of immunosuppression (intravenous steroids and OKT3), yet successfully treated with a 6-mo course of ECP. The ECP treatment was performed at weekly intervals during the first month, at 2-wk intervals during the second and third months, and then monthly for another 3 mo. Creatinine clearance improved throughout the treatment in three patients and remained unchanged in one. All patients had a pre-ECP biopsy with a grade 2 or 3 rejection (Banff) with a diffuse infiltrate CD8, CD14, LFA-1 (166 cells positive/0.048 mm2), and VLA-4 (51 cells positive/0.048 mm2) positive, as well as a tubular expression of HLA-DR (6.2 sections of tubule positive/0.048 mm2), ICAM-1, and VCAM-1 (3.1 and 2.9 sections of tubule positive/0.048 mm2). A strong reduction of cell infiltrate and expression of LFA-1 (6.6 cells positive/0.048 mm2). VLA-4 (0.7 cells positive/0.048 mm2), HLA-DR (0.2 section of tubules positive/0.048 mm2), ICAM-1 (0.3 section of tubules positive/0.048 mm2), and a disappearance of VCAM-1 staining were observed in the biopsies performed after 3 mo of ECP. All patients remained rejection-free during ECP, without infections or other complications commonly observed with increasing doses of standard immunosuppression. The clinical improvement allowed a progressive reduction of oral steroids in three of the four patients treated.

We report a simple and rapid HPLC procedure for measuring p-aminohippuric acid in serum and urine. After deproteinization with acetonitrile and addition of p-aminobenzoic acid as an internal standard, the chromatographic run is performed on a C18 column with the absorbance detector set at 275 nm. The separation is carried out in 10 min at a flow-rate of 1.0 ml/min with a mobile phase composed of 7 mmol/l 1-decanesulfonic acid, pH 3.70, and acetonitrile (82:18, v/v). The relationship between p-aminohippuric acid concentration and the p-aminohippuric acid/internal standard peak area is linear up to 100 microg/ml. Within-run precision measured at three different p-aminohippuric acid concentrations ranges from 1.73 to 1.98% in serum and from 0.72 to 1.32% in urine. Between-run precision varies from 1.80 to 4.06% in serum and from 1.05 to 2.66% in urine. Analytical recovery is between 98.26 and 99.44% in serum and from 99.57 to 100.45% in urine. The method is very simple, sensitive, and requires small volumes of sample for the assay (100 microl). Therefore, it could be a useful tool for the analysis of p-aminohippuric acid in the evaluation of renal plasma flow.

We investigated the immunohistochemical distribution of endothelin (ET) in 22 graft biopsies from kidney-transplanted patients. Like normal kidney tissue, 6/22 biopsies showed either no or only very weak ET positivity in the vascular endothelium. In the other 16 cases ET staining was marked on the vascular endothelium and wall (9/16), inflammatory infiltrates (11/16), glomeruli (7/16) and tubules (5/16). ET positivity in glomeruli and inflammatory infiltrates correlated with the degree of glomerular damage and interstitial inflammation but no correlation was found between the immunohistochemical results and the clinical variables considered. ET plasma levels (ET-PL) in patients (5.13 + 1.77 pmol/L) did not differ significantly from age-matched healthy controls (3.76 + 0.93 pmol/L), nor did ET urinary excretion (ET-U/CR-U) (33.94 + 21.89 and 24.94 + 8.5 pmol/mmol/L respectively). Neither ET-PL nor ET-U/CR-U was correlated with histological and immunohistochemical data or with the clinical variables. Our study suggests a potential role of ET as a local pro-inflammatory and growth factor in renal allografts and confirms its importance in the sequence of events involved in the progression of kidney damage.

We report the clinical and morphological features of an unusual hepatorenal disorder in 2 patients. The main clinical features were early onset of cholestatic liver disease and progressive tubulointerstitial nephritis, leading to renal death in early childhood. Renal histology showed interstitial fibrosis, tubular atrophy and dilatation, glomerular cysts in the cortex and periglomerular fibrosis; liver histology was characterized by portal fibrosis and bile duct abnormalities. Evaluating the 12 patients published in the literature, the long-term prognosis of the liver function appears bad, suggesting the possibility of a combined liver and kidney transplantation.

Photopheresis (ECP) is a new type of photochemotherapy, used for the treatment of oncological and autoimmune diseases. Lymphocytes are drawn from the patients by leukapheresis, treated with 8-methoxypsoralen (8-MOP) and ultraviolet light A (UVA) in an extracorporeal system and then reinfused. Skin exposure to 8-MOP and UVA (PUVA) has been shown to relieve cutaneous symptoms of graft-versus-host disease (GVHD) in bone marrow transplant (BMT) recipients. ECP, which is similar in some ways to PUVA, has been used in this study to treat four paediatric patients who developed chronic GVHD following BMT and in whom GVHD had failed to respond to conventional immunosuppressive therapy. Following ECP, skin lesions cleared almost completely and pulmonary function tests improved in two of three patients with cutaneous and lung involvement. Serum bilirubin and transaminases gradually normalized, and gammaGT decreased considerably in the remaining patient who had a severe cholestatic hepatopathy. The Karnofsky performance score increased to 90% in the three patients with positive responses to ECP and remained unchanged (40%) in the patient who did not respond. Immunosuppressive therapy was reduced in three patients and eventually discontinued in two. No significant side-effects were observed during the treatment. Our results suggest that ECP is a non-aggressive treatment that may benefit patients with chronic GVHD who do not respond to standard immunosuppressive therapy.

The increased frequency of prenatal detection of urinary tract abnormalities has brought to the attention of the pediatrician a high number of neonates and infants with asymptomatic hydronephrosis, which represents the most common form of uropathy. As it becomes clear that hydronephrosis does not necessarily mean obstruction, the purpose of the evaluation is to identify those infants in whom hydronephrosis will cause progressive renal deterioration, because of an ongoing restriction to urinary outflow. In the present paper, the discussion of the post-natal diagnosis and management focuses on the embryologic background, the pathophysiology of the obstruction and the rationale to utilise the different diagnostic techniques (ultrasonography, associated with the use of the Doppler; intravenous urography; avoiding cystourethrography; renal scintigraphy).

Recurrent rejection is an uncommon, severe complication after heart transplantation that is associated with a poor long-term prognosis. Photopheresis (ECP), a new form of extracorporeal photo-chemotherapy used for the treatment of cutaneous T cell lymphoma and several autoimmune diseases, has also been used for prevention and treatment of acute rejection in heart transplant recipients. It seems to induce specific suppression of both cellular and humoral rejection. In this study, we evaluated whether ECP added to standard therapies allowed better control of rejection and reduction of conventional immunosuppressive drugs in patients with repeated rejection episodes. Eight heart transplant recipients (6 men and 2 women, mean age 48 yr), with recurrent rejection were treated with ECP for 6 months. Endomyocardial biopsies (EMB) were performed monthly. As a result of treatment, 7 patients on ECP experienced a reduction of the number and severity of rejection episodes. The fraction of EMB negative for rejection increased from 13 to 41%, whereas the fraction of specimens with multifocal and/or diffuse moderate lymphocytes infiltration (grades 3A and 3B) decreased from 41 to 21%. ECP allowed reductions of daily immunosuppressive therapy: prednisone by 44% (16.9 vs. 9.4 mg), cyclosporine by 21% (366 vs. 291 mg), and azathioprine by 29% (137 vs. 97 mg). No major side effects were observed. We conclude that, although the number of patients is small, the use of ECP was safe and associated with improved control of recurrent rejection. This allowed tapering of immunosuppressive drugs, which was particularly useful in two patients with insulin-dependent diabetes and one with sternal wound osteomyelitis.

Objectives: To report the complications and outcome of 10 newborns affected by acute renal failure (ARF), treated by continuous peritoneal dialysis (CPD)., Design: All newborns admitted for tertiary treatment to the Neonatal Intensive Care Unit of the University of Padova, who underwent CPD between February 1986 and December 1990, were analyzed retrospectively., Patients: Ten newborns (mean weight 2077 g, range 540-4930 g) received CPD, 6 of whom were preterm. All the survivors completed the study., Interventions: A number 9, 5 French Tenckhoff catheter was used, and a closed circuit was created by means of a modified continuous ambulatory peritoneal dialysis (CAPD) technique. The mean duration of dialytic therapy was 7 days., Results: At the end of the dialytic period, 7 of the 10 patients had normal serum potassium and sodium values. CPD produced two different types of complications: leakage of the dialytic fluid in very low weight newborns and one episode of peritonitis during a chronic dialysis treatment. Six died of severe respiratory failure (in no case, however, was this attributable to ARF or CPD procedure). All but one of the survivors regained normal renal function. The only exception necessitated a kidney transplant., Conclusion: We believe that this technique, although invasive, improves the outcome of both preterm and low birth weight newborns affected by ARF.

In a retrospective, double-blind study, we analyzed, utilizing an immunohistochemical technique, the distribution of Endothelin (Et) in 20 renal biopsies of 17 children with nephrotic syndrome (NS): 9 cases of steroid-responsive and 8 of steroid-resistant minimal-change disease (MCD) and 3 cases of focal segmental glomerulosclerosis (FSGS). Thirteen out of 20 biopsies (9/9 steroid-responsive MCD and 4/8 steroid-resistant MCD) showed a weak positivity of the vascular endothelial cells, as the normal renal tissue samples obtained from tumor nephrectomies. Seven out of 20 biopsies, all steroid-resistant NS, showed a marked positivity of the vascular endothelium and of the tubules and/or interstitial cells. In 4 of these 7 cases (1 MCD, 3 FSGS) a positivity of glomeruli was also revealed. The positivity of vascular endothelium seems to confirm its central role in Et production. The marked immunoreactivity detected in the endothelial cells and other renal components reveals a local increase in Et in some steroid-resistant MCD and, particularly, in FSGS. These preliminary observations suggest that Et may participate (cause or epiphenomenon) in the mechanisms underlying the development of glomerulosclerosis and the progression of renal damage.

Photopheresis (ECP) is a new therapy for oncological and autoimmune diseases consisting in the reinfusion of 3-9 x 10(9) leukocytes, taken from the patient by leukapheresis, and treated in an extracorporeal system with 8-methoxypsoralen and ultraviolet light A. Nine patients affected by T cell immunomediated diseases (2 scleroderma, 1 chronic GVHD, 1 polyarteritis, 1 rheumatoid arthritis and 4 heart transplant patients with numerous episodes of acute rejection) were treated with ECP. Photopheresis was performed on 2 consecutive days every 3-4 weeks. All patients affected by autoimmune diseases experienced an improvement during treatment with ECP. In 2 of the 4 patients with heart transplant, rejection was reversed by photopheresis. No major side effects were observed during the treatment. In conclusion ECP is a safe and well tolerated therapy. Although the number of patients is small, ECP seems to be an effective modality in many diseases.

A nonradioactive in situ hybridization technique was utilized for the rapid and early diagnosis of cytomegalovirus (CMV) infection in children undergoing kidney transplantation. The cellular samples were obtained directly from the organs thought to be affected on the basis of clinical findings: bronchoalveolar lavage during interstitial pneumonia (7 samples from 6 cases); fine-needle aspiration biopsy (FNAB) of the liver during acute hepatitis (1 case); kidney FNAB and peripheral blood where there was a greater than or equal to 25% creatinine rise with or without fever (26 episodes). Standard virus isolation procedures and an immunofluorescent technique on short-term cultures of human fibroblast cells were performed as a control. 6/23 children followed had a symptomatic CMV infection (4 had interstitial pneumonia; 1 had acute hepatitis, and there was 1 case of creatinine rise with fever). In all cases, the diagnosis was provided by in situ hybridization in less than 24 h. These results were confirmed 48 h later by immunofluorescence and after 5-25 days by standard viral cultures. In situ hybridization with a biotinylated probe proved to be a rapid and sensitive method for diagnosis of CMV disease, when performed on specimens obtained from the involved organs at an early stage of the infection. This diagnostic approach allowed a specific antiviral therapy to be undertaken promptly.

The effect of intragastric nutrion and its complications, especially the reflux pattern, were studied in 104 patients, who had to be intensively treated for more than 10 days. Patients suffering from polytrauma without abdominal injury (group I) or with abdominal injury (group III) and patients with isolated head/brain injury (group II) were included in this study. Parenteral nutrition was changed to intragastric administration as soon as possible and enteral nutrition was softly increased from 327 calories per day during the first week to 1800 calories or more in the next weeks. The general duration of feeding by nasogastric tube was between 16,1 and 19,8 days. The occurrence of reflux varied from 23,2% in patients of group II to 29,4% in patients of group I. Significant changes of reflux pattern were seen during the different weeks of treatment. The amount of reflux fluid was between 184,8 ml in group II and 355,4 ml in group III. The percentage of reflux fluid, if compared with the total enteral fluid administration revealed the maximum (16,6%) in patients of group III. Patients in group I had the highest frequency of defecation, the highest incidence of diarrhea was in all the groups really the same. Diarrhoea was seen in 6,7% of all patients. The underlying mechanism for these complications were discussed.