C3, C4, factor B and HLA-DR alpha mRNA expression in renal biopsy specimens from patients with IgA nephropathy

The deposition of complement in the kidney mesangium is a constant finding associated with renal injury in IgA nephropathy, even though IgA does not bind complement. We have previously reported that complement gene expression in the kidney increases concurrently with the progression of immune complex disease in murine lupus nephritis. We have now studied the expression of C3, C4, factor B and HLA-DR alpha mRNA by in situ hybridization in renal biopsy specimens of patients with IgA nephropathy and compared these findings to those in patients with other immune-mediated diseases of the kidney, hereditary nephritis and normal kidney. In IgA nephropathy, C3 and factor B mRNA were expressed in the renal tubular epithelial cells, while no expression of either C3 or factor B mRNA was apparent in the glomerulus. Specimens from patients with other immune-mediated forms of chronic glomerulonephritis also showed a similar pattern of expression of C3 and factor B mRNA only in the tubules, but not in the glomerules. However, C3 and factor B mRNA were not found in normal kidney tissue or biopsy specimens from patients with hereditary nephritis. C4 mRNA was expressed in the tubular epithelial cells in all specimens examined, indicating that C4 mRNA is constitutively expressed in the human kidney. In IgA nephropathy HLA-DR alpha mRNA was observed in the interstitium, but not the tubules or glomerular cells. In contrast, HLA-DR alpha mRNA was present in the glomerulus and scattered in the interstitium in other immune-mediated kidney diseases. There was no expression of HLA-DR alpha mRNA in hereditary nephritis or normal kidney. Our findings, which reflect the immunopathogenic events in vivo, provide new insights as to the interpretation of the molecular immunology of this immune complex disease.

Metastatic renal carcinoma in a pediatric recipient of an adult cadaveric donor kidney

A 15-year old male with chronic renal failure secondary to obstructive uropathy received an adult cadaveric donor kidney. Evaluation for painless macroscopic hematuria occurring 2 years after transplantation disclosed a metastatic renal cell carcinoma, which by the use of restriction fragment length polymorphism analysis was shown to be of the donor's origin. Transplant nephrectomy and cessation of immunosuppressive therapy resulted in complete regression of multiple pulmonary metastases.

IgA and IgG immune complexes increase human macrophage C3 biosynthesis

We have studied the effect of IgA- and IgG-containing immune complexes on the production of complement proteins C3, factor B and C2 by human monocyte-derived macrophages, using biosynthetic labelling, immunoprecipitation, sodium dodecyl sulphate-polyacrylamide gel (SDS-PAGE) and autoradiography. There was a consistent increase in C3 production and secretion with both IgA and IgG immune complexes. This increase appeared after a 24-hr incubation period of the macrophages in the presence of immune complexes. No change in the biosynthesis of factor B and C2 proteins was observed in these experiments. Concomitant with the enhanced C3 biosynthesis, the immune complexes caused an increase in macrophage tumour necrosis factor (TNF) production; 310 + 24 U/ml/5 x 10(5) cells and 430 + 51 U/ml/5 x 10(5) cells for IgA and IgG immune complexes, respectively, versus 12 + 8 U/ml/5 x 10(5) cells in the control cells. The presence of prednisolone (2 x 10(-5) M) or dexamethasone (1 x 10(-7) M) inhibited the immune complex-induced TNF production, but had no effect on C3-increased synthesis, suggesting that the effect of immune complexes was not mediated by endogenous TNF production. These findings may be relevant to the local inflammatory response in IgA immune complex-mediated diseases, including IgA nephropathy.

HLA-B5 in the diagnosis of Behcet's disease

Behçet's disease, a multisystem disease is, by its nature, difficult to diagnose. The first manifestation of the disease may precede the appearance of other symptoms and signs essential for diagnosis by many years. In patients of Mediterranean origin, the early manifestations of the disease, may be confused with those of familial Mediterranean fever (FMF). Determination of HLA-B5 may, however, contribute to the diagnosis in children with partial manifestations of Beh,cet syndrome.

Activation of monocytes via their Fc alpha R increases procoagulant activity

There is increasing evidence in experimental models of glomerulonephritis, including IgA nephropathy, that macrophages accumulate within the affected kidneys. Increased procoagulant activity (PCA) consequent on the influx of these cells has been associated with the progression of kidney disease. We have studied the effect of activation of the monocyte Fc alpha receptor (Fc alpha R) on PCA. Immune complexes of immunoglobulin A (IgA) isotype formed in situ or the addition of aggregated IgA resulted in a dose-dependent increase of monocyte PCA. Maximal effect was achieved after 6 hours of incubation. PCA induced by Fc alpha R was consistent but was less than that observed after addition of endotoxin to monocyte monolayers or after activation via the Fc gamma R or mannose receptor. Specificity of the interaction of the ligands with Fc alpha R was shown; galactose inhibited effects mediated via the Fc alpha R but not via the Fc gamma R. Corticosteroids inhibited Fc alpha R monocyte-induced PCA. These results are likely to be relevant in the immunopathogenesis of IgA-mediated disease, particularly IgA nephropathy.

Congenital bilateral absence of vas deferens in the absence of cystic fibrosis

The high frequency of mutations in the cystic fibrosis gene in patients with congenital bilateral absence of vas deferens (CBAVD) has raised the question whether all of them have a genital form of cystic fibrosis. We investigated 47 CBAVD patients by ultrasonography, 10 (21%) had renal malformations and 37 (79%) did not. In the former group, no cystic fibrosis mutations were found and sweat chloride concentrations were normal. In the latter group, 18 patients (49%) carried at least one cystic fibrosis mutation and sweat chloride was high in 17 of 26 tested (65%). Our findings suggest that CBAVD patients with renal malformations do not necessarily have cystic fibrosis.

[Endobronchial mass caused by tuberculosis]

A 2-year-old girl who presented with cough, had been started on prednisone and bronchodilators 10 days prior to admission because of presumed hyperactive, small airway obstruction. Fluoroscopy revealed hyperinflation of the right lung and mediastinal shift to the left on expiration. Bronchoscopy disclosed an endobronchial mass. At that time the tuberculin test was negative. Since such lesions are rare in young children, thoracotomy was performed. An enlarged mediastinal lymph node was removed and the histopathological findings were suggestive of tuberculosis. The tuberculin test 1 month following prednisone therapy was positive, suggesting that previously the skin reaction to tuberculin had been altered by the prednisone. Tuberculosis should be considered in the differential diagnosis of an endobronchial mass even in an otherwise apparently healthy child.

Cross-linking of monocyte plasma membrane Fc alpha, Fc gamma or mannose receptors induces TNF production

We have studied and compared the effects of IgA and IgG immune complexes and concanavalin A (Con A) on human monocyte tumour necrosis factor (TNF) production. The presence of IgA-containing immune complexes in monocyte monolayers resulted in a dose-dependent increase of TNF production. Similar results were obtained with IgG-containing immune complexes and Con A. The presence of monomeric IgA or IgG did not increase TNF secretion. Both IgA and IgG immune complexes also increased monocyte interleukin-1 beta (IL-1 beta) production. Galactose inhibited the effect of IgA but not IgG immune complexes, while mannose inhibited the effect of Con A. Prednisolone abrogated TNF production, while indomethacin enhanced TNF production in all instances where cross-linking of plasma membrane receptors was achieved. These results indicate that activation of Fc alpha receptors (Fc alpha R), Fc gamma R or mannose receptors of the human monocyte plasma membrane by cross-linking results in increased TNF and IL-1 beta secretion. These findings may be of particular relevance in the pathogenesis of IgA immune complex-mediated disease.

Effect of short-term hyperthyroxinemia on vitamin D metabolism in congenital hypothyroidism

The circulating concentrations of vitamin D metabolites were measured in nine children (four to ten years of age) with congenital hypothyroidism on L-thyroxine therapy, before and after a short term increase (33%) in dosage. The concentrations of 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D were not altered, but the concentration of 1,25 dihydroxyvitamin D was significantly higher in the serum of the children after three weeks of hyperthyroxinemia. This was associated with an increase in urinary calcium excretion. The increases in serum concentration of 1,25 dihydroxyvitamin D cannot be explained by differences in serum levels of calcium, phosphorus or parathyroid hormone. These findings differ from data obtained in adults.

The human gene encoding cytokeratin 20 and its expression during fetal development and in gastrointestinal carcinomas

The differentiation of the predominant cell types of the mucosal epithelium of the mammalian gastrointestinal tract is characterized by increasing amounts of an intermediate-sized filament (IF) protein designated cytokeratin (CK) 20 which is a major cellular protein of mature enterocytes and goblet cells. Here we report the isolation of the human gene encoding CK 20, its complete nucleotide sequence and the amino acid sequence deduced therefrom that identifies this polypeptide (mol. wt. 48553) as a member of the type I-CK subfamily. Remarkable, however, is the comparably great sequence divergence of CK 20 from all other known type I-CKs, with only 58% identical amino acids in the conserved alpha-helical 'rod' domain of CK 20 and, e.g. CK 14. Using riboprobes corresponding to exon 6 of the gene in Northern blot and ribonuclease protection assays, we show that the approximately 1.75 kb mRNA encoding CK 20 is specifically produced in cells of the intestinal and gastric mucosa, including tumors and cell lines derived therefrom. The appearance of CK 20-positive cells in human embryonic and fetal development and in adult tissues has been studied using immunohistochemistry with CK 20-specific antibodies. CK 20 synthesis has first been recognized at embryonic week 8 in individual 'converted' simple epithelial cells of the developing intestinal mucosa. In later fetal stages, CK 20 synthesis extends over most goblet cells and a variable number of villus enterocytes. The distribution of CK 20-positive cells in the developing gastric and intestinal mucosa is similar to--but not identical with--the pattern in the adult intestine in which all enterocytes and goblet cells as well as certain 'low-differentiated' columnar cells contain CK 20, whereas the neuroendocrine ('enterochromaffin') and Paneth cells are negative. In gastrointestinal carcinomas similarly examined, CK 20 has been detected in almost all cases (50/52) of colorectal adenocarcinomas, including all grades of differentiation and malignancy and also metastatic tumors, whereas CK 20 immunostaining in gastric carcinomas has been found less consistent and more heterogeneous. The possible biological meaning of the specific expression of the CK 20 gene in certain cells of the gastrointestinal tract and carcinomas derived therefrom and the regulatory mechanisms involved in the integration of the protein in the IF cytoskeleton are discussed.

Effect of low-calorie diets on the sympathetic nervous system, body weight, and plasma insulin in overweight hypertension

When weight reduction was found to decrease blood pressure in the overweight hypertensive patient, it was hailed as the causative factor. A growing number of recent studies indicate that this association may be secondary to a correlation between diet-associated metabolic change and the sympathetic nervous system. A select group such as overweight hypertensive patients may have a genetic predisposition for such a correlation. In overweight hypertensive patients, low-calorie diet and especially very-low-calorie diet, correlate with improved glucose metabolism, a decrease in plasma insulin concentration, and altered norepinephrine concentrations and thus sympathetic nervous system activity. Several of these studies also show a lack of effect of salt intake on blood pressure. Thus, it seems that metabolic changes caused by the decrease in caloric intake are responsible for the decrease in blood pressure. These must be investigated to understand the effect of the different diets on blood pressure. Very low-calorie diets were found very useful in breaking the vicious circle of severe nonresponsive hypertension to medication.

Cytokeratin 20 in human carcinomas. A new histodiagnostic marker detected by monoclonal antibodies

The authors have recently identified a new cytokeratin (CK) polypeptide, CK 20, whose expression is almost entirely confined to the gastric and intestinal epithelium, urothelium, and Merkel cells. Seven monoclonal antibodies (MAbs) specific for CK 20 were raised and characterized by applying immunoblotting and immunocytochemical screening. All of them reacted on frozen tissue sections. A further MAb, IT-Ks20.8, recognized CK 20 in sections of formalin-fixed, paraffin-embedded tissue samples. A total of 711 cases of primary and metastatic cancer, mostly carcinomas, were analyzed immunohistochemically for CK-20 expression, using CK-20 specific guinea-pig antibodies and MAbs. The expression spectrum of CK 20 in carcinomas resembled that seen in the corresponding normal epithelia of origin. CK-20 positivity was seen in the vast majority of adenocarcinomas of the colon (89/93 cases), mucinous ovarian tumors, transitional-cell and Merkel-cell carcinomas and frequently also in adenocarcinomas of the stomach, bile system, and pancreas. Most squamous cell carcinomas in general and most adenocarcinomas from other sites (breast, lung, endometrium), nonmucinous tumors of the ovary, and small-cell lung carcinomas were essentially or completely negative. The authors propose to use CK 20 as a diagnostic marker valuable in distinguishing different types of carcinomas, notably when presenting as metastases.

Urolithiasis in children: current medical management

The mechanism of stone formation in the urinary tract is reviewed. Diet, urinary tract infection and metabolic disorders account for the different epidemiological patterns of stone formation. The diagnosis and management of renal tract calculi are discussed. Calcium stones are associated with hypercalciuria, urine acidification defects, the use of furosemide in premature babies, hypercalcaemia, hyperoxaluria, hyperuricosuria, an alkaline urine and hypocitraturia. Uric acid stones occur in acid urine, from increased purine synthesis with lympho- or myeloproliferative disorders or from several inborn errors of purine metabolism which can also cause xanthine or dihydroxyadenine stones. Cystinuria, inherited as an autosomal recessive disorder is best treated with a low sodium diet, a fluid intake exceeding 40 ml/kg per day maintaining urine pH between 7.5 and 8 and, if necessary, with oral penicillamine. Oxalate stones occur in relation to diet, bowel disease and primary inherited defects in oxalate metabolism. Urinary tract infection causing struvite and carbonate apatite formation is the commonest cause of stones in Europe.

Plasma exchange for recurrent nephrotic syndrome following renal transplantation

Patients with steroid-resistant nephrotic syndrome and focal segmental glomerulosclerosis (FGS) who develop end-stage renal disease are at risk for recurrence of the disease following renal transplantation. Recurrence of the nephrotic syndrome in renal allografts of two children with primary FGS was successfully controlled by plasma exchange. This report suggests that plasma exchange instituted early in the course of recurrent nephrotic syndrome may be beneficial in some patients with steroid-resistant nephrotic syndrome and FGS.

Familial vesicoureteral reflux: a study of 16 families

Siblings of patients with vesicoureteral reflux (VUR) are reported to have an increased incidence of reflux. We present 16 families with 33 affected children out of a total of 493 patients with VUR. Twenty-seven had urinary tract infection and 6 were asymptomatic and were examined because a sibling had VUR. Renal scarring was present in 19 cases; reflux was more marked and more often bilateral in the siblings than in sporadically affected children. In view of our findings we suggest that siblings of patients with VUR be screened early for reflux to prevent renal damage from untreated VUR.

Anuria in a premature infant due to ureteropelvic fungal bezoars

Systemic candidiasis with renal involvement is a well recognised complication of intensive care in premature newborns. However, the development of reversible obstructive oliguric acute renal failure has not been well documented. We report a premature infant who developed anuria associated with bilateral candidal bezoar formation in the renal collecting system. The sonographic appearance of the renal fungus balls is described. Treatment by surgical removal of the bezoars, open placement of nephrostomy tubes and intravenous antifungal therapy resulted in apparent complete recovery.

Damage to the middle ear and the inner ear in underwater divers

Postmortem human tissue from recently deceased divers was processed histologically to assess any inner and middle ear damage that could have resulted from the effects of pressure during diving. The following new findings are particularly noteworthy. In one diver, ascent while breath holding resulted in the rupture of the ear drum and blood in the middle ear, in addition to pulmonary barotrauma. In a second diver, following inner ear decompression sickness, new bone growth, similar to that described earlier in experimental studies with the squirrel monkey, was observed in the arms of one of the semicircular canals. These observations are further confirmation that otologic disorders can be a serious threat to divers.

[Cutaneous-mucous hyalinosis (Urbach-Wiethe disease). Histologic and ultrastructural study of a case]

Hyalinosis cutis et mucosae is a rare genetic disorder, primarily involving skin and mucous membranes, that has been described under various titles as lipoidosis lipoproteinosis and Urbach-Wiethe disease. A 17-year-old girl presented cutaneous macular lesions, skin scars, thickened lips and enlarged firm tongue; hoarseness was known since birth. The labial biopsy specimen was investigated by light and electron microscopy. Histologically there are deposits of amorphous, extra-cellular eosinophilic hyaline material in the upper thickened connective tissue. In the lower part changes are focal with hyaline mantle around the vessels. Histochemical studies have revealed that the deposits were PAS-positive and amylase-resistant, indicating the presence of neutral mucopolysaccharides. Lipid stains were positive, especially in vessel walls. Ultrastructurally hyaline substance is composed of 1 to 2 nm protofilaments, larger ones (5 to 10 nm wide) and amorphous material. Fibroblasts contain in their dilated cisternae amorphous material. A frequent feature is marked multilamination of the capillary basal lamina which is interpenetrated by hyaline substance. Pathogenesis is still unknown but recently it is suggested hyalinosis cutis et mucosae could be a systemic disease of basal lamina.