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Biomedical subjects

J Rapola

Publications and source records attributed to J Rapola.

At least 19 recordsLinked to original sources

Cyclosporin reduces renal prostanoid excretion in type 1 diabetic patients.

Prostacyclin and thromboxane A2 are important regulators of kidney blood flow. To examine whether changes in their metabolism could be involved in the nephrotoxicity of cyclosporin, we determined urinary excretion of 6-keto PGF1a and dinor-6-keto PGF1a (prostacyclin metabolites) and dinor-TxB2 (thromboxane metabolite) in five newly diagnosed type 1 diabetic patients during and after stopping cyclosporin therapy. In the resting state, cyclosporin had no effect on prostanoid excretion. In response to exercise, urinary excretion of 6-keto PGF1a was reduced by 50% (P less than 0.02), dinor-6-keto PGF1a by 15% (P less than 0.05) and dinor-TxB2 by 45% (P less than 0.02), while albumin excretion increased 4.5-fold (P less than 0.05) during cyclosporin therapy. Simultaneously, there was a rise in serum creatinine concentration, and renal biopsy specimens obtained from three patients showed periglomerular and interstitial fibrosis and tubular atrophy. After the discontinuation of cyclosporin therapy, serum creatinine concentrations returned to normal, histological changes improved and there was an associated rise in urinary prostanoid excretion. These data suggest that a reduction in renal prostanoid synthesis by cyclosporin may diminish renal blood flow and function, and lead to histological changes in the kidney.

6-Ketoprostaglandin F1 alpha

The glycosaminoglycan content of renal basement membranes in the congenital nephrotic syndrome of the Finnish type.

A decrease in the concentration of heparan sulphate proteoglycan (HSPG) in the glomerular basement membrane (GBM) is supposed to cause the increased GBM permeability in the congenital nephrotic syndrome (CNS). Therefore, we analysed the glycosaminoglycan (GAG) content and composition of the GBM and tubular basement membrane (TBM) from 3 patients with CNS of the Finnish type (FCNS) and 16 control infants. The GAG content, determined by spectrophotometric assay after papain digestion, was not significantly different in FCNS patients compared with controls. In addition, the GAG composition was comparable in the two groups, with heparan sulphate (HS) constituting at least 75% of the total GAG content. The urinary GAG content (expressed as mg GAG/mmol creatinine) was age dependent, but similar in both groups. Indirect immunofluorescence studies on kidney tissue from normal human infants, using monoclonal or polyclonal antibodies against the core protein of human GBM HSPG, showed linear staining of almost all renal basement membranes. A monoclonal antibody directed against the HS chain of HSPG showed strong GBM and a weak TBM staining. Kidney tissue from three patients with FCNS displayed no discernible differences in the distribution or quality of staining with the same antibodies. These biochemical and immunohistochemical results are in contrast to the decrease in anionic sites (by polyethyleneimine staining) and the replacement of GBM HS by chondroitin sulphate, observed by others in CNS of the diffuse mesangial sclerosis type.

Basement Membrane

Nonvacuolar myopathy in a large family with both late adult onset distal myopathy and severe proximal muscular dystrophy.

Late adult onset distal myopathies usually show vacuolar degeneration as a characteristic feature in muscle pathology. In this study vacuolar degeneration was not present in 12 patients with late adult onset distal myopathy. All patients were members of a large kindred, with 26 patients showing this new form of distal leg myopathy. Additionally, a severely disabling proximal muscular dystrophy appeared in eight other members of the large consanguineous kindred. Muscle biopsies were obtained from clinically affected muscles, and from clinically unaffected muscles in patients with distal myopathy. For comparison specimens from various muscles of patients with severe proximal dystrophy were also studied. Histopathological changes correlating to muscular dystrophy were extensive in all muscles studied in patients with proximal dystrophy, and in tibial anterior muscles in patients with distal myopathy. Mild myopathic changes, mainly increased internal nuclei in muscle fibers, were detected in clinically unaffected muscles in the distal myopathy. The spectrum of findings is compatible with the hypothesis of previous clinical and genetic studies, indicating that the severe proximal dystrophy could be a homozygous manifestation of the dominantly inherited gene of the distal tibial muscle dystrophy.

Adult

Reversible mitochondrial myopathy with cytochrome c oxidase deficiency.

Two siblings, a boy and a girl born in a nonconsanguineous marriage, presented with a similar clinical course. Sucking and breathing difficulties appeared within a few weeks of birth. Clinical examination revealed profound muscular hypotonia, hepatomegaly, increased serum creatine kinase activities, and lactic acidosis. Both infants were treated with gavage feeding, the boy also needing ventilatory support. Clinically they improved gradually. Now, the boy aged 4 years and the girl aged 28 months are free of clinical signs. Muscle biopsy specimens taken at 3 months showed, in both, ragged red fibres, abnormal mitochondria, and reduced cytochrome c oxidase (COX) staining. Biochemical analysis showed COX activity to be reduced to about 25% of the normal mean. The second biopsy specimen from the boy at 16 months was normal on morphological examination, but the girl's second specimen at 13 months still showed abnormal features. These cases are examples of the rare benign reversible COX deficiency. Early diagnosis is crucial to provide intensive treatment until spontaneous clinical improvement appears.

Biopsy

Chronic rejection of rat renal allograft. III. Ultrastructure of vascular and glomerular changes.

The main histological features for 'chronic' rejection of rat renal allograft are ongoing perivascular and interstitial inflammation, vascular intimal hyperplasia and glomerular sclerosis. In this communication we have investigated the ultrastructural features of renal parenchyma by comparing chronically rejecting rat renal allografts immunosuppressed initially with cyclosporine to similarly immunosuppressed syngeneic transplants. Electron microscopy confirmed that the primary arterial change was smooth muscle cell proliferation in media, thickening and focal destruction of the internal elastic lamina, and influx of smooth muscle cells and their proliferation in the intima, leading to a nearly complete occlusion of the lumen. In the glomeruli, the most prominent features were mesangial matrix increase, narrowing of capillary lumen, and basement membrane thickening with a double contour appearance in capillary walls. A thin membrane, similar to lamina densa, appeared beneath the endothelium in some segments. Mesangial interposition, formation of new basement membrane and mesangial widening due to increase of basement membrane-like material was nearly always present. As none of these vascular and glomerular changes were observed in similarly immunosuppressed syngeneic transplants, we consider these ultrastructural alterations characteristic for chronic rejection in a rat renal allograft.

Animals

Kidney biopsy findings in cyclosporine-treated patients with insulin-dependent diabetes mellitus.

Renal biopsy specimens of 40 patients with recent-onset insulin-dependent diabetes mellitus treated with cyclosporine (CSA) for 6-29 months were examined. Cyclosporine-associated chronic vascular interstitial toxicity of moderate intensity was found in 10 patients (25%). The most prominent lesions were interstitial fibrosis and tubular atrophy. Arteriolopathy was less pronounced and glomerular damage unremarkable. A significant correlation exists between the extent of tubular atrophy and CSA trough whole blood levels. These data indicate that the development of CSA-associated chronic nephropathy is dose-dependent.

Adolescent

DNA-based prenatal diagnosis of the infantile form of neuronal ceroid lipofuscinosis (INCL, CLN1).

Eleven fetuses at risk for the infantile form of neuronal ceroid lipofuscinosis (INCL, CLN1) were studied using DNA markers and the results were compared with the results of electron microscopy (EM) of chorionic villus specimens from pregnancies in the first or early second trimester of pregnancy. In four cases, the prenatal diagnosis was made independently with both methods, and in seven cases, the EM diagnosis was confirmed postnatally or from autopsy material using RFLP analysis. The two methods gave concordant results in all cases. The DNA analysis based on RFLP haplotypes also for the first time facilitates reliable carrier diagnostics. RFLP analysis based on polymorphic markers closely linked to the INCL locus is now available for prenatal diagnosis of this fatal brain disease, whose biochemical background is totally unknown and for which no treatment is available.

Chorionic Villi Sampling

The spectrum of Jansky-Bielschowsky disease.

A series of five patients with a variant type of Jansky-Bielschowsky disease is presented. The disease initiated between four and a half and seven years with mental and slight motor symptoms. The additional neurological symptoms and signs, i.e. visual failure, retinal degeneration, ataxia, myclonia and epilepsy developed in all children before the age of ten years. The present series differs from our previous series of 16 cases especially in regard of neurophysiological findings (photic spikes, high visual evoked potential, VEP and high somatosensory evoked potential, SEP). VEP became abnormally high between 8.0 and 9.5 years instead of being an early finding as in the previous series. Photic spikes appeared also later in the present series. Electromicroscopic investigation revealed cytosomes with fingerprint profiles (FP) in the autonomic ganglion cells and cytosomes with both FP and curvilinear (CP) profiles in many extraneural cells including smooth muscle, Schwann cells, capillary endothelium and macrophages. In the light of our 21 Finnish patients and the literature, the spectrum of Jansky-Bielschowsky disease seems to be much wider than previously assumed. The diagnosis should be based on clinical, ophthalmological, neurophysiological and ultrastructural findings. Repeated neurophysiological studies may be necessary.

Age Factors

Cell-surface ganglioside GD2 in the immunohistochemical detection and differential diagnosis of neuroblastoma.

The expression of the disialoganglioside GD2 was analyzed in 67 solid tumors and normal tissues from children by using the GD2-specific murine monoclonal antibody 3A7 and the indirect immunoperoxidase method. GD2 was expressed in all of 28 neuroblastomas and was most abundant in stroma-poor tumors. In differentiating stroma-rich neuroblastomas, neuroblastic clusters, neurofibrils, and most ganglion-like cells were positive, whereas Schwann's-cell stroma did not express GD2. In ganglioneuromas, only a few ganglion-like cells showed GD2, whereas all other structures were negative. Scattered foci of ganglioside GD2 also were found in some non-neuronal tumors, such as rhabdomyosarcomas and osteosarcomas, but not in lymphomas, Askin tumors, or most Wilms' tumors. The monoclonal antibody 3A7 is a useful aid in the immunohistochemical diagnosis of neuroblastoma. In addition, the intense cell surface staining of neuroblastoma cells by this reagent makes it potentially useful for detecting residual neuroblastoma in bone marrow samples and lymph node biopsies.

Antibodies, Monoclonal

Prenatal diagnosis of the infantile type of neuronal ceroid lipofuscinosis by electron microscopic investigation of human chorionic villi.

Chorionic villus biopsy specimens were studied electron microscopically in six pregnancies at risk of the infantile type of neuronal ceroid lipofuscinosis (INCL). The biopsy was performed in all cases in the first trimester of pregnancy (8-10 gestation weeks) by the transcervical route. In one case, the biopsy was repeated at 17 weeks by the transabdominal procedure. In two pregnancies, the endothelial cells and, to a lesser extent, the mesenchymal cells of the chorionic villi contained unit membrane-bound inclusions typical of INCL. In both cases, the pregnancy was terminated and in one of them identical inclusions were found in the brains and kidneys of the fetus at 20 weeks of gestational age. The children from the remaining four pregnancies are healthy and have shown no signs of the disease.

Chorionic Villi Sampling

The rectourogenital connection in anorectal malformations is an ectopic anal canal.

Histological investigation of the rectal blind pouch and rectourogenital or rectoperineal connection was performed in 10 patients with high or intermediate anorectal malformations. Nine of the patients underwent postoperative manometric evaluation. In nine of the 10 patients, transitional epithelium typical of the normal anal canal could be found in the distal rectum or rectal end of the fistulous connection. The zone of transitional epithelium was aganglionic and showed abnormally strong acetylcholinesterase reaction. A positive rectoanal inhibitory reflex was found manometrically in all cases in which the distal rectal pouch was utilized in the reconstruction of the anal canal. The slow pressure wave activity of the reconstructed anal canal was characteristic of a normal anal canal. The manometric evidence strongly suggests that there is a functional internal sphincter in high and intermediate anorectal malformations. The present study shows that in anorectal malformations the distal rectal pouch with the fistulous connection is actually an ectopic anal canal.

Anal Canal

Cell differentiation in sacrococcygeal teratomas. An immunohistochemical and follow-up study.

The cell differentiation properties of thirty-four sacrococcygeal teratomas (SCT) and their five recurrences were immunohistochemically studied for the expression of different classes of intermediate filament proteins, muscle actin (MA) and S-100 protein. Out of thirty-nine tumors twenty-three were SCTs with only mature tissue elements, seven immature teratomas, five pure endodermal sinus tumors (EST) and four ESTs or embryonal carcinomas (EC) combined with mature components. Cytokeratin positivity was found in all epithelial structures and sometimes also in smooth muscle and primitive mesenchymal cells. An intense cytokeratin immunoreactivity was observed in EC and EST components. Muscle markers, desmin and MA were present in smooth and striated muscle cells. Focal desmin positivity was also found in some epithelial structures in two cases. Glial tissue positive for glial fibrillary acidic protein (GFAP) was found in twenty-eight out of thirty-nine tumors. Some cases with no apparent glial tissue in hematoxylin and eosin staining showed glial differentiation as proved by GFAP positivity. In six out of eleven choroid plexus-like tissues GFAP positive cells were observed. S-100 protein showed an intense distribution of immunoreactivity outside neural tissue, and focal positivity was observed in malignant epithelial structures. Immunohistochemical markers did not reveal any prognostic significance in teratomas. Our findings, however, showed some aberrant features of cell differentiation from normal mature tissue components but closely parallel to those found in normal fetal development.

Actins