Accelerated diabetic glomerulopathy in galectin-3/AGE receptor 3 knockout mice.

Several molecules were shown to bind advanced glycation end products (AGEs) in vitro, but it is not known whether they all serve as AGE receptors and which functional role they play in vivo. We investigated the role of galectin-3, a multifunctional lectin with (anti)adhesive and growth-regulating properties, as an AGE receptor and its contribution to the development of diabetic glomerular disease, using a knockout mouse model. Galectin-3 knockout mice obtained by gene ablation and the corresponding wild-type mice were rendered diabetic with streptozotocin and killed 4 months later, together with age-matched nondiabetic controls. Despite a comparable degree of metabolic derangement, galectin-3-deficient mice developed accelerated glomerulopathy vs. the wild-type animals, as evidenced by the more pronounced increase in proteinuria, extracellular matrix gene expression, and mesangial expansion. This was associated with a more marked renal/glomerular AGE accumulation, indicating it was attributable to the lack of galectin-3 AGE receptor function. The galectin-3-deficient genotype was associated with reduced expression of receptors implicated in AGE removal (macrophage scavenger receptor A and AGE-R1) and increased expression of those mediating cell activation (RAGE and AGE-R2). These results show that the galectin-3-regulated AGE receptor pathway is operating in vivo and protects toward AGE-induced tissue injury in contrast to that through RAGE.

Kidney transplantation in a girl with methylmalonic acidemia and end stage renal failure.

Methylmalonic acidemia (MMA) is an inborn error of organic acid metabolism that occurs in infancy with hypotonia, vomiting, dehydration, lethargy and failure to thrive and is biochemically characterized by metabolic ketoacidosis, hyperammonemia and sometimes hyperglycinemia. It results from deficiency of methylmalonyl-CoA mutase activity due to a defect in the mutase apoenzyme or to deficient function of one of the enzymes required for metabolism of its cofactor vitamin B12. Tubulointerstitial nephritis with progressive impairment of renal function is one of the most frequent long-term complications. We describe a case of a 17-year-old girl with methylmalonic acidemia unresponsive to vitamin B12 therapy. The clinical symptoms appeared at 4 months of life. She progressed into end stage renal disease and in January 1996 she started on hemodialytic treatment. In November 1996 we performed a kidney transplant. At present, urinary excretion of methylmalonic acid is normal and the renal function of the transplanted kidney is normal without any rejection episodes. We think that a kidney transplant could be a good therapeutic choice for the metabolic alterations in MMA with end stage renal disease. Indeed it would seem that the small methylmalonyl-CoA mutase activity present in the transplanted kidney could be sufficient to ensure normal metabolism of organic acids. Otherwise, the therapeutic goal can be achieved with a protein-restricted diet.

Distribution of alpha-chains of type IV collagen in glomerular basement membranes with ultrastructural alterations suggestive of Alport syndrome.

BACKGROUND: In Alport syndrome (AS) impaired production and/or assembly of col IV alpha-chain isoforms results in abnormal structure of glomerular basement membrane (GBM), haematuria and, frequently, progressive renal disease. We investigated the relationship between col IV alpha-chains expression and morphology of GBM, as a possible key to the better understanding of the pathogenesis of renal disease in AS. METHODS: GBM distribution of col IV alpha1-, alpha3-, and alpha5-chain was investigated by immunohistochemistry in 32 patients (21 males and 11 females, mean age at biopsy of 11.5 years) with ultrastructural findings suggestive of AS. Ten patients had a proven COL4A5 mutation. Based on the severity of ultrastructural findings, the biopsies were grouped in three (I-III) electron microscopy (EM) classes. Significant EM changes of GBM (thinning, thickening, splitting, basket weaving of the lamina densa) were singularly evaluated using a semiquantitative scale (0-3). RESULTS: Col IV alpha1-chain was demonstrated in GBM of all patients. Three patterns of staining for col IValpha3- and alpha5-chains were observed: positive, negative, and alpha3(IV)-positive/alpha5(IV)-negative. By chi(2)-test, EM class III lesions and complete loss of alpha3(IV)- and alpha5(IV)-antigen were significantly more frequent (P<0.05 and P<0.01) in male patients, but no significant relation was observed between EM classes and immunohistochemical patterns. GBM alterations did not correlate with staining for alpha5(IV)-chain. Intensity of alpha3(IV)-chain staining, however, had a negative correlation (P<0.05) with the severity of GBM basket weaving. CONCLUSIONS: Our results suggest that the alpha3(IV)-chain-containing col IV-network plays a fundamental role in structural and, possibly, functional organization of GBM. Absence of alpha3(IV)-chain in GBM could indicate a more severe renal disease in AS.

Increased retinal endothelial cell monolayer permeability induced by the diabetic milieu: role of advanced non-enzymatic glycation and polyol pathway activation.

BACKGROUND: Increased vascular permeability could be involved in the pathogenesis of diabetic retinopathy. The present study was aimed at assessing whether high glucose concentrations can impair retinal endothelial cell barrier function directly, irrespective of changes in other determinants of permeability, and the role of non-enzymatic glycation and polyol pathway activation in these alterations. METHODS: Bovine retinal endothelial cells (BREC) were exposed for various periods to high glucose vs iso-osmolar mannitol and normal glucose containing media+/-agents mimicking or inhibiting advanced glycation end product (AGE) formation and polyol pathway activation. Monolayer permeability was assessed by measuring the transendothelial passage of (125)I-labeled proteins. RESULTS: Permeability increased significantly (up to +70%) in BREC exposed to high glucose, but not to mannitol, for 1-30 days, vs normal glucose control cells. Exposure to AGE-modified bovine serum albumin (BSA) (> or = 90%) and, to a lesser extent, sorbitol (+28%) mimicked the high glucose effect. The AGE formation and nitric oxide synthase (NOS) inhibitor aminoguanidine significantly reduced (by 60%) changes induced by 30-day exposure to high glucose, whereas methylguanidine, which inhibits only NOS activity, did not affect permeability. Aldose reductase or sorbitol dehydrogenase inhibitors decreased (by approximately 40%) the enhanced leakage produced by 1-day, but not 30-day, incubation in high glucose. CONCLUSIONS: The present results indicate that high glucose is capable of impairing retinal endothelial cell barrier function directly and that non-enzymatic glycation and polyol pathway activation may mediate these changes, with AGEs participating in the long-term alterations and increased flux through the sorbitol pathway in the short-term effect.

Pathogenesis of the glomerular abnormality in cyanotic congenital heart disease.

We present evidence of 2 distinct glomerular abnormalities in cyanotic congenital heart disease--vascular and nonvascular--each believed to reflect a distinct pathogenesis. Glomeruli from both kidneys were studied with light microscopy in 13 necropsied cyanotic patients and in 8 controls. The vascular study characterized hilar arteriolar dilatation, capillary diameter, glomerular diameter, and capillary engorgement with red blood cells. The nonvascular study characterized juxtaglomerular cellularity, mesangeal cellularity, mesangeal matrix, focal interstitial fibrosis, and megakaryocytic nuclei per cm2 of renal cortex. There was a significant increase in each of the above vascular and nonvascular items of interest relative to controls. Electron microscopy identified whole megakaryocytes with their cytoplasm in glomeruli. The vascular abnormality is believed to result from intraglomerular release of nitric oxide. The nonvascular abnormality is believed to result from platelet-derived growth factor and transforming growth factor-beta.

Role of galectin-3 as a receptor for advanced glycosylation end products.

The advanced glycosylation end product (AGE)-binding proteins identified so far include the components of the AGE-receptor complex p60, p90 and galectin-3, receptor for advanced glycosylation end products (RAGE), and the macrophage scavenger receptor types I and II. Galectin-3 interacts with beta-galactoside residues of several cell surface and matrix glycoproteins through the carbohydrate recognition domain and is also capable of peptide-peptide associations mediated by its N-terminus domain. These structural properties enable galectin-3 to exert multiple functions, including the modulation of cell adhesion, the control of cell cycle, and the mRNA splicing activity. Moreover, in macrophages, astrocytes, and endothelial cells, galectin-3 has been shown to exhibit a high-affinity binding for AGEs; the lack of a transmembrane anchor sequence or signal peptide suggests that it associates with other AGE-receptor components rather than playing an independent role as AGE-receptor. In tissues that are targets of diabetic vascular complications, such as the mesangium and the endothelium, galectin-3 is not expressed or only weakly expressed under basal conditions, at variance with p90 and p60 but becomes detectable with aging and is induced or up-regulated by the diabetic milieu, which only slightly affects the expression of p90 or p60. This (over)expression of galectin-3 may in turn modulate AGE-receptor-mediated events by modifying the function of the AGE-receptor complex, which could play a role in the pathogenesis of target tissue injury. Up-regulated galectin-3 expression may also exert direct effects on tissue remodeling, independently of AGE ligands, by virtue of its adhesive and growth regulating properties.

Delayed onset of systemic lupus erythematosus in patients with "full-house" nephropathy.

Three patients are described who presented with a glomerulopathy suggestive of lupus nephritis in the absence of other clinical and biological evidence of systemic lupus erythematosus (SLE). Renal biopsies showed a "full-house" immunofluorescence pattern and two patients also had cytoplasmic tubuloreticular inclusions by electron microscopy. All these patients developed antinuclear and anti-double-stranded DNA antibodies 3, 5, and 10 years after their original presentation. Subsequently, 1 patient also developed clinical symptoms of lupus. Reviewing all renal biopsies performed in our department, we found 14 additional patients who presented with a "full-house" immunofluorescence glomerulonephritis in the absence of other features of SLE. After a mean follow-up of 5.8 years, these patients have not developed serological or clinical evidence of SLE. We conclude that a "full-house" glomerulopathy in children may be the first symptom of SLE, especially when cytoplasmic tubuloreticular inclusions are detected. The appearance of other clinical and biological symptoms may be delayed by several years.

[Supraventricular arrhythmia after pneumonectomy. Apropos of 100 cases and review of the literature]. / Troubles du rythme supraventriculaire après pneumonectomie. A propos de 100 cas et d'une revue de la littérature.

Supraventricular arrhythmias are frequently observed in pneumonectomy surgery. We retrospectively studied a series of 100 consecutive patients undergoing pneumonectomy for cancer between 1994 and 1996. We found 24% of significant supraventricular arrhythmias, corresponding to atrial fibrillation in 75% of cases, occurring in 80% of cases until the third postoperative day. The only risk factor significantly associated with these arrhythmias was the patient's age. These arrhythmias are easily reduced, spontaneously in 25% of cases, and usually by amiodarone, alone or associated with digitalis alkaloids. While the mortality of the overall group was 12%, 8% of patients with arrythmia died. These deaths concerned patients whose arrythmias occurred after the fourth postoperative day in a context of a pulmonary infection.

Cervical bronchogenic cyst mimicking thyroid adenoma.

Bronchogenic cysts are congenital malformations of the foregut which are generally encountered within the mediastinum. We explored a patient presenting with a cystic, partially calcified tumor in a cervical and retrotracheal location. This lesion was interpreted as a thyroid adenoma preoperatively, but identified as a bronchogenic cyst at pathology.

Ultrastructural and immunohistochemical findings in Alport's syndrome: a study of 108 patients from 97 Italian families with particular emphasis on COL4A5 gene mutation correlations.

A total of 108 patients affected by Alport's syndrome, taken from 97 families, were enrolled in a genetic and ultrastructural study. Sixty-four families (75 patients) were X-linked, seven autosomal recessive, two autosomal dominant, five uninterpretable, and 19 sporadic. The ultrastructural features were consistent with Alport's syndrome in 66, doubtful in 20, and not significant for Alport's syndrome in 22 patients in the X-linked, sporadic, and genetically uninterpretable groups (without significant differences), as well as in the autosomal group. Mutations of the COL4A5 gene were present in 36 patients in the first three groups, without significant differences. More severe mutations were more frequently present in patients with an ultrastructural pattern consistent with Alport's syndrome. Nevertheless, there seems to be no strict correlation between mutation and ultrastructure, because a major rearrangement was found in a patient with no significant lesions, and different morphologic patterns were detected in patients Belonging to the same family. Immunohistochemical investigation into 24 patients for alpha (IV) chains showed that both alpha 3(IV) and alpha 5(IV) were lacking in the glomerular basement membrane of 13 patients (five with mutations) and were expressed in another six (three with mutations and one in the autosomal group). On the contrary, in this study the retained expression of alpha 3(IV) chain was found, despite the lack of alpha 5(IV) in the glomerular basement membrane of five patients (two with mutation). These different patterns could be related to both the type and severity of the COL4A5 mutations. All of the ultrastructural patterns were identified in all three immunohistochemical groups. Ultrastructural features and alpha 5(IV) chain production, even if an expression of a genetic mutation, do not strictly correlate. The combined use of analysis of collagen expression and electron microscopy made it possible to diagnose Alport's syndrome in 92% of the cohort, and therefore this approach is advisable. A multidisciplinary approach is recommended in the study of Alport's syndrome in an attempt to achieve a better diagnostic definition of and insight into the pathogenetic mechanisms.

Operative risk and prognostic factors of typical bronchial carcinoid tumors.

BACKGROUND: This study estimated operative risk and examined factors determining long-term survival after resection of typical carcinoid tumors. METHODS: From 1976 to 1996, 139 consecutive patients (66 male and 73 female patients with a mean age of 47 +/- 15 years) underwent thoracotomy for typical carcinoid tumor. The tumors were centrally located in 102 patients (73.4%). RESULTS: Radical resection was performed in 106 patients (7 pneumonectomies, 13 bilobectomies, and 86 lobectomies) and conservative resection in 33 (3 segmentectomies, 3 wedge resections, 20 sleeve lobectomies, and 7 sleeve bronchectomies). There were no postoperative deaths. Complications occurred in 19 patients (13.7%). The morbidity rate was not increased after bronchoplastic procedures (chi 2 = 0.033, not significant). Staging was pT1 in 107 patients (77.0%) and pT2 in 32 (23.0%); 13 patients (9.4%) had nodal metastases. Seventeen patients have died (12.2%), during follow-up, but only three deaths were related to the disease. The overall survival rate at 5, 10, and 15 years was estimated to be 92.4%, 88.3%, and 76.4%, respectively; estimated disease-free survival was 100% at 5 years and 91.4% at 10 and 15 years. Estimated survival of patients with lymph node metastasis was 100% at 5, 10, and 15 years. Univariate analysis failed to demonstrate any prognostic significance for sex, tumor size (T1 versus T2), tumor location (central versus peripheral), and type of resection. CONCLUSIONS: These data confirm an excellent prognosis after complete resection of typical carcinoid tumors, including those with lymph node metastases. Parenchyma-saving resections should be preferred.

Bronchopulmonary aspergilloma: a reappraisal.

BACKGROUND: Classically, most complications observed after operations for aspergilloma occurred in patients with sequelae of tuberculosis. Because the incidence of tuberculosis has declined over the past two decades, aspergilloma is expected to develop with increasing frequency in patients without previous tuberculosis. Therefore, our hypothesis was that operative outcome should have improved during the most recent years in comparison with our previous experience. METHODS: Operative outcome of 12 recently accrued patients was evaluated and compared with a historic control group of 55 patients, previously reported by the same center. RESULTS: As expected, only 17% of patients of the present series had a history of tuberculosis, compared with 57% in the former series. Postoperatively, there was no mortality. Major morbidity has decreased, although this difference is not statistically significant: bleeding decreased from 44% to 9% of patients; space problems decreased from 47% to 18%; and prolonged hospital stay (>30 days) decreased from 32% to 9%. CONCLUSIONS: Our results support a trend toward improved postoperative outcome of operations for aspergilloma owing to a decreased incidence of aspergilloma growing in tuberculous cavitations.

Long-term complications of extraperiosteal plombage.

BACKGROUND: As soon as complications due to migration of extraperiosteal plombage material had been documented, early removal became the rule. Some patients who have escaped this rule may still present with long-term complications. METHODS: Since 1980, 14 patients aged 54 +/- 10 years were admitted 28 +/- 11 years after collapse therapy. Eight presented with signs of infection, 4 with hemoptysis, and 2 with periscapular pain. Vascular erosion, suspected in 3 patients, was demonstrated with angiograms in 1. RESULTS: Ablation of the material was combined with excision of the devitalized ribs in 13 patients. Femorofemoral bypass was used in 2 patients for repair of an aortic erosion. Single ablation of subcutaneously migrated material was performed in a poor-risk patient. Operative bleeding was moderate except in 2 patients; 1 of them died intraoperatively during repair of an aortic erosion. A second patient died postoperatively with a massive pulmonary embolus on day 11. Infection was diagnosed in 8 patients (Mycobacterium tuberculosis, 4; and pyogens, 4). Operative outcome was satisfactory in all 12 operative survivors. A single patient presented with an infected apical space at 1 year and underwent complementary resection of the first rib. CONCLUSIONS: We recommend routine ablation of any residual plombage material whenever operative risk is acceptable because of the high incidence of spontaneous complications.

Pneumonectomy for chronic infection is a high-risk procedure.

BACKGROUND: The purpose of this study was to estimate operative risk, and to identify indicators of adverse prognosis, in patients undergoing pneumonectomy for chronic infection. METHODS: Twenty-five patients aged 41 +/- 15 years underwent pneumonectomy (three completions) for chronic infection: sequelae of tuberculosis, 15; cystic bronchiectasis, 9; and radiation pneumonitis, 1. Eight patients had aspergilloma (7 after tuberculosis, 1 with radiation pneumonitis). RESULTS: Operative mortality was 4%. Operative blood loss was estimated at 1,983 +/- 1,424 mL, ranging from 150 to 5,600 mL. A single patient required reexploration. Eight patients (32%) had empyema, and a further 3 (12%) had bronchopleural fistula; thoracoplasty was required for 10 (40%). Sequelae of tuberculosis heralded increased operative bleeding (t = 2.884; p < 0.005). Incidence of empyema or bronchopleural fistula was increased in patients with sequelae of tuberculosis (chi 2 = 3.896; p < 0.05), patients with aspergilloma (chi 2 = 4.588; p < 0.05), patients in whom the parenchymal cavities were entered (chi 2 = 11.5; p < 0.001), and those in whom blood loss was in excess of 1,000 mL (chi 2 = 4.911; p < 0.05). CONCLUSIONS: We conclude that pneumonectomy is a high-risk procedure, especially in patients with sequelae of tuberculosis.

[Do pericardial strips (Peri-Strip) facilitate the follow-up after pulmonary surgery in emphysematous patients?]. / Les bandelettes de péricarde (Peri-Strip) facilitent-elles les suites après chirurgie pulmonaire chez le patient emphysémateux?

The aim of this study was to evaluate the contribution of bovine pericardial strips (Peri-Strip) to achieve aerostasis within emphysematous lungs. A preliminary evaluation included 15 patients (13 men and 2 women, mean age 57 years) with severe emphysema (mean FEV-1: 28.6 +/- 10.2% of predicted, mean RV: 18.4 +/- 41.3% of predicted). Two patients were on ventilator owing to acute respiratory failure. Indication for surgery was elective surgery for emphysema in 9 patients, emergency surgery for emphysema in 2, and resection for bronchogenic cancer in 4 patients. The various procedures included single aerostasis in 1, unilateral bullectomy in 6, bilateral volume reduction in 4, thoracoscopic wedge resection for peripheral cancer in 1 and lobectomy for cancer in 3 (2 of which underwent simultaneous bullectomy) Peri-Strip were used to buttress the staple lines at the base of bullae, on parenchymatous transsection lines, and on the borders of fissures. One patient who underwent emergency thoracotomy for single aerostasis died 8 days post-operatively due to multiple organ failure. Another patient developed pneumonia which resolved under treatment. Mean duration of air leaks was 5.6 days (0-21, median 8). Two patients required tube thoracotomy for residual effusions. Mean hospital stay was 17 days (6-53; median 16). We conclude that use of Peri-Strip offered a real benefit to 12 patients; no evidence of benefit was noted in 3 patients.

[Cystic dystrophy on an aberrant duodenal pancreas. Apropos of a case]. / Dystrophie kystique sur pancréas aberrant duodénal. A propos d'une observation.

Cystic dystrophy of the aberrant pancreas is a rare poorly understood condition which is difficult to diagnose and treat. The primary clinical signs are epigastralgia associated with poor general health and complications due to stenosis of the duodenum. Endoscopy gives the most information on tissue lesions and cystic formations in the duodenal mucosa. Although the condition is benign, and due to the lack of sufficient history in endoscopically treated cases, cystic dystrophy of the aberrant duodenal pancreas appears to require duodenopancreatectomy.