Anti-neuronal antibodies in patients with HCV-related mixed cryoglobulinemia.

Mixed cryoglobulinemia (MC) is an immunological disorder characterized by immune-complex-mediated systemic vasculitis involving small vessels, which may present with renal, cutaneous, rheumatologic, and/or neurological manifestations. Until recently, the possible appearance of anti-neuronal autoantibodies in peripheral neuropathy occurring in the context of hepatitis C virus (HCV)-associated IgMk/IgG MC has not been extensively addressed. Therefore, a sample of these patients were evaluated by means of immuno-enzyme methods of anti-neuronal autoantibody detection. A significant increase in plasma titers of both anti-GM1 ganglioside and anti-sulfatide was observed. Abnormal titers were associated with evidence of active neuropathy as assessed by electrophysiologic studies. While peripheral neuropathy was traditionally thought to result from axonal ischemic damage caused by deposits of cryoprecipitable immune complexes in the vasa nervorum, a significant association between anti-GM1 and anti-sulfatide antibodies and involvement of the peripheral nervous system was observed in HCV-associated mixed IgMk/IgG cryoglobulinemia. Anti-neuronal reactivity could be a direct trigger of neurologic injury in this disorder.

Mass spectrometry analysis of IgA1 hinge region in patients with IgA nephropathy.

BACKGROUND: Physicochemical alterations of the IgA molecule are supposed to play a pathogenetic role in IgA nephropathy (IgAN). The present study was carried out to analyze the structural variety of O-glycans on the IgA1 hinge region in IgAN. Sera from 9 IgAN patients and 9 healthy controls were individually examined to evaluate the IgA1 content and binding lectins (jacalin and Helix aspersa), using enzyme-linked immunosorbent assay (ELISA) techniques. The IgA1 from pooled sera were separated by affinity chromatography (jacalin), and the fragment containing the hinge region was prepared by pyridylethylation and trypsin treatment. The IgA fragments containing the hinge glycopeptide (33-mer hinge peptide core (HP) + O-glycans) were separated by jacalin affinity chromatography. Because we used jacalin, we only analyzed the Gal-3GalNAc residue containing IgA. The molecular weight (MW) of the IgA1 fragments was estimated using an ion trap mass spectrometer equipped with an electrospray ion source (ESI/MS). RESULTS: IgA1 concentration in pathological sera was higher than in the control serum (p<0.01). Compared with controls, serum IgA1 from IgAN patients showed significantly greater binding to the 2 lectins, jacalin (p<0.01) and Helix aspersa (HA, p<0.001), which are specific for O-linked Gal-beta1,3-GalNAc and GalNAc, respectively. Analyses of pooled sera showed that the number of O-glycosidic chains was comparable in IgAN and normal sera. With regards to the individual residues, we found that IgAN sera contained less sugar and galactose and sialic acid moieties than sera from control subjects, was reduced in IgAN sera, while terminal N-acetylgalactosamine levels were higher when compared with normal serum. CONCLUSIONS: Abnormalities of hinge region O-linked glycans were confirmed using advanced spectrometry technology. The pathogenetic implications for aggregation and defective removal of IgA1 are discussed.

Anti-GM1 and anti-sulfatide antibodies in patients with systemic lupus erythematosus, Sjögren's syndrome, mixed cryoglobulinemia and idiopathic systemic vasculitis.

OBJECTIVES: Over the last two decades, increasing interest has been focused on the association between autoimmune polyneuropathies and anti-neuronal autoantibodies in immune-mediated polyneuropathy. The possible appearance of these autoantibodies in systemic diseases that are not limited to the nervous system has not been fully addressed yet. METHODS: We evaluated 32 patients with systemic lupus erythematosus, 34 patients with hepatitis C virus-associated mixed IgM-k/IgG cryoglobulinemia, 19 with small vessel ANCA-associated vasculitis, and 20 patients with Sjögren's syndrome by means of an immunoenzyme method of anti-neuronal autoantibody detection. RESULTS: As compared to normals, a significant increase (p < 0.001) in plasma titers of both IgM and IgG anti-GM1 ganglioside and IgM and IgG anti-sulfatide was observed in patients with systemic lupus erythematosus, mixed cryoglobulinemia and Sjög-ren's syndrome. Idiopathic systemic vasculitis patients were found to have significantly increased levels of anti-sulfatide IgG autoantibodies (p < 0.001). Clinical and electrophysiologic studies revealed that abnormal titers of anti-neuronal antibodies were associated with evidence of neuropathy in patients with systemic lupus erythematosus and ANCA-related vasculitis (p < 0.05) as well as in patients with mixed cryoglobulinemia and Sjögren's syndrome (p < 0.001). CONCLUSION: Anti-GM1 and anti-sulfatide antibodies are frequently found in patients with small vessel ANCA-associated vasculitis and other multi-organ immune-mediated diseases. Upon detection of these antibodies, accurate neurologic examination should be carried out due to the significant association that can be found between these serologic abnormalities and the involvement of the peripheral nervous system as also detected by electrophysiologic studies. This study supports the unexpected possibility that anti-neuronal reactivity may be a direct trigger of neurologic injury in these systemic disorders.

Mycophenolate mofetil and roscovitine decrease cyclin expression and increase p27(kip1) expression in anti Thy1 mesangial proliferative nephritis.

The response of mesangial cells to a phlogistic challenge includes cell proliferation and mesangial matrix expansion. Cell proliferation is a highly regulated process which includes enhancing factors such as cyclins, cyclin dependent kinases, and inhibitory proteins, such as p27(kip1). The aim of the study was to evaluate the effects of Mycophenolate mofetil (MMF), and roscovitine (R), on the cell cycle regulatory system when administered in the florid phase of the experimental model of mesangial proliferative nephritis induced by the anti Thy-1 antigen monoclonal antibody. Three days after nephritis induction, different groups were given MMF and R. Rats treated with MMF or R showed a slight decrease in mesangial proliferation and matrix expansion. Samples of cortical tissue were tested by 'real time' RT-PCR in order to study gene expression of cyclins B, D1, D2, D3, E, and the cyclin inhibitor p27(kip1). Localization of mRNA was evaluated by in situ hybridization. Real time RT-PCR analysis showed a significant decrease in cyclins B, D1, D2, and D3 in rats treated with either MMF or R as compared to controls. Both MMF and R treatment induced a significant increase in p27(kip1) mRNA expression. In situ hybridization showed a mesangial-endothelial expression pattern in glomeruli. The number of labelled cells per glomerulus, the number of positive glomeruli in each examined slide as well as cyclin D2 and D3 signal intensity was significantly lower in rats treated with MMF or R as compared to controls, whereas MMF or R treatment up-regulated p27(kip1) mRNA expression. Immunohistochemical evaluation of p27(kip1) aimed to examine the influence of MMF or R on protein expression confirmed up-regulation.

[Anti-GM1 and anti-sulphatide antibodies in systemic idiopathic vasculitis, systemic lupus erythematosus and mixed cryoglobulinaemia: Serum detection and clinical and electrophysiologic correlations]. / Gli anticorpi anti-GM1 ed anti-solfatidi nelle Vasculiti sistemiche primitive, nel Lupus eritematoso sistemico e nella Crioglobulinemia mista: dosaggio sierico e correlazioni clinico-elettromiografiche.

BACKGROUND: In the last two decades increasing interest has been focused on the association between autoimmune polyneuropathies and high titers of anti-nervous serum autoantibodies. High titer of IgG anti-GM1 antibody could be detected in Guillain Barre' syndrome and in chronic painful axonal sensory immune-mediated polyneuropathy. The possible occurrence of anti-nervous autoantibodies in autoimmune diseases not limited to the nervous system is still under study. METHODS: We evaluated 29 patients with systemic lupus erythematosus (SLE), 19 with biopsy-proven renal involvement, 28 patients with mixed IgM-K/IgG polyclonal cryoglobulinaemia (18 with glomerulonephritis) and 19 with small-sized vessel ANCA-associated vasculitis (12 with renal involvement) by using a sensitive immunoenzyme method of autoantibody detection. RESULTS: Compared to controls (1/176+/-1/205; 1:204+/-1:103), we found a significant increase in plasma IgM and IgG anti-GM1 titers (1:643+/-1:531; 1:444+/-1:309) in SLE patients (p<0.0001). We also found IgM (1:3032+/-1:2844) and IgG (1:1560) anti-sulphatide titers to be higher than the control group (p<0.0001). Mean plasma IgM and IgG anti-GM1 titers of the cryoglobulinaemic patients were 1:524+/-1:403 and 1:501+/-1:415, respectively, once again higher than the controls (p<0.0001). Mean plasma IgM and IgG anti-sulphatide titers in this group were 1:1864+/-1:1189 and 1:1350 (p<0.0001). We found idiopathic systemic vasculitis patients to have significantly increased levels of anti-sulphatides IgG class autoantibodies (1:1400; p<0.0001). We found no correlation with the serologic markers for vasculitis or the clinical or histologic extent of renal involvement. Electrophysiologic studies revealed that in 38% of SLE patients (p<0.005), 61% of cryoglobulinaemic patients (p<0.01) and 42% of ANCA-related vasculitic patients (p<0.01) the abnormal titers of antineuronal antibodies were associated with clinical or subclinical evidence of neuropathy. CONCLUSIONS: In patients with systemic idiopathic or secondary vasculitis anti-GM1 and anti-sulphatide antibodies can frequently be found. Their presence should prompt an accurate neurological examination because these serologic abnormalities are significantly associated with neurologic, often subclinical, involvement. Antineuronal reactivity might be the epiphenomenon of primary phylogistic damage, which exposes normally segregated neuronal epitopes or be directly involved in triggering neurological injury.

Steroid and cyclophosphamide in IgA nephropathy.

BACKGROUND: IgA nephropathy is associated with a wide spectrum of possible lesions. Therefore, different responses to anti-inflammatory or immunosuppressive therapies should be expected with acute inflammatory changes, which are predominantly reversible, and with prevalently sclerotic lesions. METHODS: The effects of a combined schedule of prednisone and cyclophosphamide was analysed in the specific subset of IgA nephropathy patients with acute inflammatory histologic changes associated with haematuria and proteinuria. Two groups of patients, with similar histologic lesions and clinical presentation, were considered. The first group (12 patients) was treated within 1 week after renal biopsy; starting with three pulses of methylprednisolone (1 g) followed by oral prednisone (0.8 mg/kg body weight for 2 weeks, 0.6 mg/kg for another 2 weeks, 0.4 mg/kg for an additional 4 weeks, then slowly tapered by 5 mg each month until discontinuation) and 1.5 mg/kg cyclophosphamide for 2 months. A second sample of eight untreated patients served as a control group. Treated and untreated patients had diffuse mesangial proliferation with florid crescents (8-60% in treated and 10-40% in untreated patients) with mild degree of glomerular sclerosis and interstitial changes. Basal creatinine (167 micromol/l, range 79-371 vs 132 micromol/l, range 79-256) and proteinuria (3.0 g/24 h, 1.0-4.9 vs 3.3 g/24 h, 1.0-13.7) were not statistically different between treated and untreated patients respectively. Nine treated and six untreated patients were hypertensive. Blood pressure treatment did not include ACE-inhibitors. RESULTS: Untreated patients' 5-year renal survival, as assessed by the Kaplan-Meier method, was found to be significantly lower than treated patients (37.5 vs 91.6%, log-rank P=0.01 and Breslow test P=0.008; relative risk to reach the endpoint of a 100% increase in serum creatinine=3.58, P=0.03). CONCLUSION: This short course of therapy with prednisone and cyclophosphamide has been effective in a subset of IgA nephropathy patients with florid glomerular changes and major urinary abnormalities, turning off phlogistic activity and preventing subsequent progression toward renal failure.

Effects of angiotensin II blockade on nitric oxide blood levels in IgA nephropathy.

BACKGROUND: The effects of renin-angiotensin system blockade on nitric oxide (NO), especially in pathological conditions, are far from being established. The influence of kinins and angiotensin type 2 receptor are largely speculative and based mainly on animal studies. This study was aimed to address these aspects in humans. METHODS: Eight IgA nephropathy patients with documented clinical and histological indicators of poor prognosis were given 50 mg of losartan, 10 mg of enalapril, and 40 mg of the NO donor isosorbide 5 mononitrate (as a control of NO generation) in randomized order for 7 days each. Treatment periods were separated by washout periods of 7 days each. Laboratory investigations were performed before and after each study period. Seven healthy controls received losartan and enalapril according to the same study design. RESULTS: Glomerular filtration rate remained stable while effective renal plasma flow increased with each treatment (P<0.05). Under losartan and enalapril, filtration fraction fell (P=0.02), plasma renin activity increased (P<0.05) and urinary aldosterone concentration decreased (P=0.02). Angiotensin-converting enzyme activity was reduced to the limit of detection under enalapril (P<0.001). Blood NO, detected as nitrosylhaemoglobin by a recently developed technique of spin-trap electron paramagnetic resonance, increased significantly, as expected, during treatment with isosorbide 5 mononitrate (P=0.01), with enalapril (P<0.05), and also with losartan (P<0.05). Unlike losartan, enalapril significantly reduced albuminuria (P=0.01) in this short-term period. In the seven healthy controls, neither enalapril nor losartan were able to increase blood NO levels significantly. CONCLUSIONS: Blood levels of nitrosylhaemoglobin, a surrogate marker of NO, increased under blockade of the renin-angiotensin system in patients with IgA nephropathy, but not in healthy volunteers. This increase could contribute to changes of effective renal plasma flow in renal disease states.

Met overexpression confers HGF-dependent invasive phenotype to human thyroid carcinoma cells in vitro.

The proto-oncogene c-MET encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF), a pleiotropic cytokine controlling growth, survival, motility, invasive migration, and differentiation of epithelial cells. Like several other epithelial neoplasms, thyroid carcinomas have been found to overexpress c-MET at both the mRNA and protein level. The biological relevance of Met overexpression to thyroid carcinoma natural history, however, remains to be elucidated. Therefore, we analyzed Met expression and response to HGF in two cell lines established from human thyroid carcinomas. In both lines we observed that the overexpressed and constitutively tyrosine phosphorylated HGF receptor maintained biochemical responsiveness to the ligand. Both cell lines were also found to respond to HGF by consistently increasing their motility and invading in vitro reconstituted basal membranes. Conversely, no effect of HGF could be observed in proliferation and survival assays. These data show that overexpression of Met specifically confers to transformed thyroid cells a motile-invasive phenotype that is dependent on exogenous HGF stimulation.

Gene expression of 5-lipoxygenase and LTA4 hydrolase in renal tissue of nephrotic syndrome patients.

Leukotrienes (LT) of the 5-lipoxygenase pathway constitute a class of potent biological lipid mediators of inflammation implicated in the pathogenesis of different models of experimental glomerulonephritis. The key enzyme, 5-lipoxygenase (5-LO), catalyses oxygenation of arachidonic acid to generate the primary leukotriene LTA4. This LT, in turn, serves as a substrate for either LTA4 hydrolase, to form the potent chemoattractant LTB4, or LTC4 synthase, to produce the powerful vasoconstrictor LTC4. To investigate the potential role of LT in the pathogenesis of human glomerulonephritis with nephrotic syndrome, we examined the gene expression of 5-LO and LTA4 hydrolase in renal tissue of 21 adult patients with nephrotic syndrome and 11 controls. The patients consisted of 11 cases of membranous nephropathy (MN), seven focal and segmental glomerulosclerosis (FSGS), two non-IgA mesangial glomerulonephritis and one minimal change disease. Total RNA purified from renal tissue was reverse transcribed into cDNA and amplified with specific primers in a polymerase chain reaction (RT-PCR). Eight patients' renal tissue, four MN and four FSGS, co-expressed 5-LO and LTA4 hydrolase. In situ hybridization analysis revealed 5-LO expression and distribution limited to the interstitial cells surrounding the peritubular capillaries. Comparative clinical and immunohistological data showed that these eight patients had impaired renal function and interstitial changes that significantly correlated with 5-LO expression. These findings suggest that leukotrienes may play an important role in the pathogenesis of MN and FSGS. These results are also relevant to elucidating the pathophysiologic mechanisms which underlie progression to renal failure in these diseases.

Intradialytic cytokine gene expression.

Along with the numerous technological improvements in molecular biology, polymerase chain reaction, which permits analysis of sequences of a very small amount of biological material, enables evaluation of hemodialysis-induced gene transcription of inflammatory cytokines. Blood samples drawn from 22 hemodialysis patients, treated with cellulose-derived or synthetic membranes, were collected at 0 and 15 min of hemodialysis. Total RNA, purified from mononuclear cells, was reverse transcribed and cDNA amplified by polymerase chain reaction primed with specific oligomers in order to determine tumor necrosis factor alpha (TNF alpha), interleukin (IL) 1 beta and IL6 gene expression. Plasma samples were collected at 0 and 180 min for detection of mature cytokines by enzyme immunoassay with plates pre-coated with monoclonal antibodies to TNF alpha, IL1 beta and IL6. A significant increase in TNF alpha mRNA was detected at 15 min of hemodialysis in 12 of 22 patients: 5 of 9 treated with cuprophan; 3 of 3 with cellulose triacetate; 3 of 5 with polysulfone, and only 1 of 5 treated with polymethyl-methacrylate membranes. A parallel increase in IL1 beta or IL6 mRNA was detected, and significant relationships were found between TNF alpha and IL1 beta (p < 0.001), and IL1 beta and IL6 gene expression (p < 0.05). Increased levels of mature TNF alpha and IL1 beta molecules in plasma were detected in the majority of patients showing an increased cytokine gene expression. However, the absolute amount of cytokine mRNA transcription at 15 min did not predict the levels of mature molecules reached in plasma at 180 min. Cytokine mRNA transcription is quite common at the beginning of a dialysis run. Possibly due to intracellular degradation of critical sequences of cytokine mRNA, gene expression does not necessarily imply translation into mature protein. It is suggested that mechanisms related to cell-to-cell interaction, which may possibly involve procytokine biology, are needed to drive phenomena of cytokine activation to clinical effectiveness.

5-Lipoxygenase gene expression in hemodialysis.

Leukotrienes (LTs), the end products of the eicosanoid pathway released during inflammation, are markers of polymorphonuclear cell and monocyte activation. The present study focused on the possibility that 5-lipoxygenase (5-LO), the key enzyme for LT synthesis, was involved in the interaction between blood and the hemodialysis (HD) membrane. 5-LO gene expression was examined by reverse transcriptase polymerase chain reaction (RT-PCR) in samples of mononuclear cells isolated from peripheral blood withdrawn at the start and at 15 min of HD from 10 chronic HD patients, 5 treated with Cuprophan and 5 with polymethylmethacrylate (PMMA) membrane. An increased 5-LO gene expression was detected at 15 min in 4 of 5 patients using the Cuprophan membrane but in none of the 5 PMMA treated patients. Our results showed for the first time that the interaction between blood and the HD membrane upregulates 5-LO messenger ribonucleic acid (mRNA).

Nonoperative management of pancreatic injuries in children.

PURPOSE: The safety and efficacy of nonoperative management of pancreatic contusions and transections was examined by reviewing the case histories of 35 consecutive children with pancreatic injuries treated over the past 10 years. METHODS/RESULTS: Surgical exploration was performed for the management of associated injuries only. The diagnosis of pancreatic trauma was suspected in children with abdominal pain, tenderness, elevated serum amylase levels and findings consistent with pancreatic injury on abdominal ultrasound scan or computerized tomography (CT) examination. After children were diagnosed with pancreatic injury, enteral feedings were withheld and total parenteral nutrition administered until abdominal pain resolved and serum amylase levels and radiographic findings improved. Twenty-three children received diagnosis within 24 hours of injury, and in 12, the diagnosis was delayed 2 to 14 days. Hyperamylasemia was found in 27 of 35 children. Twenty-eight children sustaining pancreatic injuries were treated nonoperatively. Abdominal imaging in these children demonstrated pancreatic contusion in 14, transection in 11, and pseudocyst in three. Enteral feeding resumed an average of 15 days after injury. The average hospital stay was 21 days. Pseudocysts formed in 10 children (2 of 14 with contusion; 5 of 11 with transection; three children presented late, and the type of pancreatic injury could not be determined), whose average hospital stay was 25 days. All pseudocysts were successfully managed nonoperatively, although percutaneous aspiration or drainage was required in six children. Children underwent follow-up for an average of 10 months after injury (range, 1 to 144 months). Abdominal pain and radiological abnormalities resolved in all children before discharge from the clinic. CONCLUSIONS: Nonoperative management of pancreatic contusion and transection diagnosed radiologically is effective and safe. Pseudocysts may form after pancreatic injury, and if large or symptomatic, can be managed successfully by percutaneous drainage.

Impaired hepatosplenic elimination of circulating cryoglobulins in patients with essential mixed cryoglobulinaemia and hepatitis C virus (HCV) infection.

The pathogenic mechanisms that lead to renal deposition of the cryoprecipitable IgM rheumatoid factor-IgG complexes in essential mixed cryoglobulinaemia (EMC) are unknown. Defective removal of cryoprecipitable complexes from the circulation has been postulated in EMC-associated nephritis. To test this hypothesis, the kinetics and fate of a trace dose of 123I-radiolabelled autologous cryoglobulins were analysed in 13 patients with EMC grouped according to renal involvement. The time course of radioactivity distribution in the blood and organ uptake were measured by gamma camera scintigraphy. In blood sampled 30-300 s after injection, only a minor fraction (< 15%) of the circulating cryoglobulins bound to the erythrocytes, suggesting the elimination mechanisms are independent of binding to CR1 on erythrocytes. The overall blood disappearance curve showed a fast (< or = 1 min) and slow (> 4 h) biphasic pattern. In patients with quiescent or mild nepthritis, the liver and to a lesser extent the spleen were the major organs that mediated the rapid uptake and processing of the cryoglobulins from the circulation. In contrast, patients with active mesangiocapillary glomerulonephritis showed significantly (P < 0.001) less hepatic uptake, low liver-to-precordium ratio, and slower processing of cryoglobulins, prolonged liver mean transit time, than quiescent patients or mild nephritis patients. To elucidate the role and influence of HCV infection in the pathogenesis of EMC-nephritis, sera and cryoglobulins from all patients were assayed for HCV. None of the control group cases without nephritis showed any evidence of HCV-RNA in serum or cryoglobulin pellet. In contrast, all 10 EMC-nephritis patients' sera, and eight corresponding cryoglobulin pellets contained HCV-RNA. Collectively, these findings suggest an impaired reticuloendothelial system removal of IgM-IgG-HCV complexes may underlie their renal deposition.

Processing of IgA aggregates in a rat model of chronic liver disease.

Heavy alcohol intake and/or lipotrope-deficient diet induced hepatocellular injury and mesangial deposition of IgA and often IgG in Lewis rats. The experimental animals showing more severe urinary abnormalities and histologic damage in the glomeruli had increased levels of IgA antibodies to dietary antigens and altered intestinal permeability. Based on human studies, the prolonged circulation of IgA-containing complexes associated with the liver disease could be envisaged as important for the development of mesangial IgA deposits. In order to verify this hypothesis, four groups (G) of Lewis rats were studied: G1 received thrice a weak an intragastric infusion of 1.5 ml/100 g body wt of whiskey; G2 rats were nourished with lipotrope-deficient diet; G3 rats were given both whiskey and LD diet; G4 rats were nourished with regular chow. After 12 weeks, heat-aggregated rat monomeric IgA was labeled with 133I and intravenously injected. Three control subgroups of rats, one given whiskey, one nourished with LD diet, and one with regular chow, were injected with radiolabeled heat-aggregated rat IgG. A large field-of-view digital gamma camera, equipped with an ultra-high-resolution collimator and interfaced to a dedicated computer, was used to analyze tracer kinetics and fate. The liver was the main organ involved in clearance of both test probes. The hepatic mean transit (MTT) was 11.4 +/- 11 min in G1 (proteinuria of 6.9 +/- 1.41 mg/day and hematuria +/+2), 221 +/- 19 min in G2 (proteinuria 9.1 +/- 0.64 mg/day and hematuria +2/+3), and 230 +/- 15 min in G3 (proteinuria 9.5 +/- 0.58 mg/day and hematuria +2/+3). In each case MTT value was found to be significantly prolonged compared to G4 (85 +/- 4 min). The multiple regression analysis showed that MTT values, proteinuria, and hematuria were significantly correlated (P < 0.01). Controls had trace amount proteinuria (0.82 +/- 0.17 mg/day, significantly lower than for each study group, P < 0.08) and undetectable hematuria. Similar results were obtained in control rats injected with aggregated IgG; i.e., MTT values were more prolonged in rats given whiskey or LD diet than normally nourished rats (P < 0.01). The lipotrope-deficient diet and the chronic alcohol abuse per se seem to lead to critical changes in hepatic uptake and catabolism of both an IgA and an IgG aggregate, which could account in turn for the reported appearance of renal immunoglobulin deposits in this experimental model. Due to the comparable delay in removal of IgA and IgG probes in equally nourished animals, additional factors are likely to be involved in the prominent deposition of IgA.

Diagnosis and management of duodenal injuries in children.

Traumatic duodenal perforations in children pose a diagnostic and therapeutic challenge. To identify specific diagnostic criteria and define an optimal therapeutic protocol, we reviewed all duodenal injuries treated at our institution in the past 10 years. There were 14 hematomas and 13 perforations. The diagnosis was confirmed by computed tomography (CT), ultrasound scan (US), upper gastrointestinal contrast studies (UGI), or at laparotomy. The clinical findings and CT findings of the two groups were compared. Children with suspected duodenal hematomas were treated expectantly, and children with duodenal perforations were treated surgically. Twenty-five associated injuries (10 pancreatic) occurred in 19 children. Children with perforations had higher injury severity scores (ISS) (25 v 9), but the two groups could not be differentiated based on presenting signs, symptoms, or laboratory findings. CT findings of retroperitoneal air or contrast were seen in 9 of 9 perforations and in 0 of 10 hematomas. CT findings of intraabdominal or retroperitoneal fluid, mesenteric enhancement, and thickened duodenal wall did not differentiate the two groups. Duodenojejunostomy was performed in one patient, and primary repair was performed in 11 children who had perforation. In five children, duodenostomy tube drainage with feeding jejunostomy or gastrojejunostomy were added. Complications occurred in three of four children in the first 5 years of the study and in two of nine children in the last 5 years. The decreased morbidity rate correlated with reduced time to definitive therapy (28 v 7.8 hours). Duodenal fistulae resulted in three of seven children treated without duodenostomy tube drainage and zero of five treated with drainage. Enteral feeds resumed faster (average, 12 v 27 days) if repair of perforation was combined with feeding jejunostomy or pyloric exclusion and gastrojejunostomy. Children with duodenal hematoma resumed eating an average of 16 days after injury. Only one child required surgery for persistent obstruction. The findings of retroperitoneal air and contrast extravasation on CT accurately distinguish duodenal perforation from hematoma. Conservative management of hematoma is safe and effective. Primary repair of perforation with duodenal drainage results in fewer postoperative complications, and gastrojejunostomy or feeding jejunostomy shorten the time to resumption of feeds.

[The complement system in kidney diseases]. / Il sistema del complemento in nefropatologia.

The multifaceted relations between complement system and immune-mediated nephropathies are reviewed. Several conditions in which either the complement activation induces renal damage without hypocomplementemia or hypocomplementemia occurs in the absence of circulating IC are reported as well as disorders in which immune complexes promote hypocomplementemia. The complement system is involved in the clearance of immune complexes, both modifying the immune complex size and favouring the physiologic neutralization by the erythrocyte transport system. In certain pathological conditions the immune complex intrinsic characteristic or genetic abnormalities prevent efficient removal from the blood stream. The purpose of the present review is to summarize these conditions, briefly describing their pathological consequences, and indicate a simple scheme to correctly interpret the biochemical abnormalities of the complement system in nephropathology.

Early increase in blood nitric oxide, detected by electron paramagnetic resonance as nitrosylhaemoglobin, in haemodialysis.

The objective of this study was to determine intradialytic blood levels of nitric oxide (NO), in patients undergoing chronic haemodialysis. This was done by detection of nitrosylhaemoglobin by a sensitive technique of spin trap electron paramagnetic resonance at 0, 5, 15, 60, 180 and 240 min of a 4-h standard bicarbonate dialysis, using the same dose (6000 U) of heparin and different dialysis membranes. The study group included 12 patients treated with cellulose-derived dialysis membranes (nine with cuprophan and three with cellulose triacetate) and 10 patients treated with synthetic membranes (five with polysulfone and five with polymethylmethacrylate). Control groups included 11 normal subjects and six patients with end-stage renal failure who were receiving intermittent peritoneal dialysis. Basal blood levels of nitrosylhaemoglobin in haemodialysis patients were significantly higher than normals, but similar to peritoneal dialysis patients. A significant increase (P < 0.01) in nitrosylhaemoglobin level was detected at 15 min of haemodialysis irrespective of the membrane used. A decrease to basal levels at 180 min was observed in all but two cuprophan-treated patients who, in contrast to the others, had a symptomatic hypotension at the end of the session and a further increase in blood nitric oxide. Patients undergoing peritoneal dialysis did not show any change in blood levels of nitrosylhaemoglobin during the first 180 min of the procedure. Thus, a constant increase in nitrosylhaemoglobin levels was observed early in haemodialysis, but not in peritoneal dialysis patients. Very preliminary evidence was obtained for a role of nitric oxide in the vascular instability at the end of haemodialysis in a few patients who had hypotensive episodes.