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Biomedical subjects

P Thorner

Publications and source records attributed to P Thorner.

At least 73 records · Page 4Linked to original sources
PubMed1991

Dietary modification reduces splitting of glomerular basement membranes and delays death due to renal failure in canine X-linked hereditary nephritis.

Affected male (AM) Samoyed dogs with X-linked hereditary nephritis (HN) demonstrate splitting of all of their glomerular basement membranes (GBM) and rapidly develop renal failure within the first year of life, features reminiscent of those seen in male patients with X-linked HN. In contrast, carrier female (CF) dogs with X-linked HN show only isolated foci of splitting of GBM, and renal failure is never seen at such an early age. In the present study, we assessed whether a diet designed for dogs in renal failure could modify the changes seen in GBM of AM and CF dogs and improve the clinical outcome in the AM dogs. Beginning at 35 days of age, one group of dogs (unaffected, AM, and CF) was fed a regular diet, while a second group was fed a modified diet (i.e., restricted in protein, lipid, calcium, and phosphorus). AM dogs fed the modified diet showed less of a reduction in glomerular filtration rate than AM dogs fed the regular diet, indicative of a delay in the onset and a decrease in the severity of renal damage. Nevertheless, all of the AM dogs eventually died of renal failure regardless of diet. However, the onset and progression of renal failure were delayed and the severity of splitting of GBM was reduced in the AM dogs fed the modified diet; these dogs lived 53% longer than AM dogs fed the regular diet. CF dogs fed the modified diet also showed a reduced severity of splitting of GBM. In addition, when two CF dogs on the modified diet were switched to the regular diet, splitting of their GBM increased, indicating that continual administration of the modified diet was required to maintain the reduced rate of splitting. These studies indicate that dietary modification is beneficial in canine X-linked HN, and suggest that similar benefits (i.e., reduction in severity of splitting of GBM and delay in development of renal failure) might be observed in patients with HN who are treated with an appropriately modified diet.

Animals↗
PubMed1990

Pediatric onset of Behçet's syndrome with myositis: case report and literature review illustrating unusual features.

We report a case of Behçet's syndrome with myositis in a pediatric patient, emphasizing the importance of muscle involvement in the differential diagnosis of calf pain and swelling in Behçet's syndrome. A review of the English-language literature from 1965 to the present suggests that the clinical picture of Behçet's syndrome in children differs from that in adults, in that there is a lower frequency of ocular disease, and unusual manifestations appear to be more common.

Adolescent↗
PubMed1990

Maxillary myxoma in children.

Myxoma of the maxilla is a rare, slowly growing, benign mesenchymal tumor. Pathologically, it may be difficult to differentiate from other tumors with myxoid stroma and is occasionally misinterpreted as malignant. This tumor is particularly uncommon in children; in a search of the literature, we were able to document only 17 cases of myxomas in the maxilla in patients aged 14 years or less. This report on two children with myxoma of the maxilla emphasizes the importance of including myxoma in the differential diagnosis of children with maxillofacial tumors, and underlines the difficulties in making a correct diagnosis.

Diagnosis, Differential↗
PubMed1990

Submucosal injection of polyvinyl alcohol foam in rabbit bladder.

Submucosal injection of either polytetrafluoroethylene (Teflon) or collagen has been used in the treatment of vesicoureteral reflux. Although the methods and principles of this treatment are effective, there are concerns regarding the safety and long-term effectiveness of these substances. We present a pilot study to explore the potential of an alternate substance (polyvinyl alcohol foam) for this treatment. Polyvinyl alcohol foam (Ivalon) particles measuring 150 to 250 mu. were injected submucosally into the bladder of New Zealand white rabbits. The bladder was examined macroscopically and microscopically at 1 and 2 weeks, and 1, 2 and 3 months after the injection. The particles created a raised lesion under the mucosa that was visible to the naked eye as late as 3 months after the submucosal injection. The particles remained in a submucosal location after 3 months. At 1 week after injection there was a foreign body giant cell response to the particles. At 3 months the giant cell response persisted and the particles were surrounded by a fibrotic reaction. There was little inflammatory response otherwise. These preliminary results indicate that polyvinyl alcohol foam may be suitable for subureteral injection in the treatment of vesicoureteral reflux.

Animals↗
PubMed1990

Recurring giant-cell granuloma at the site of previous radiation therapy.

A 15-year-old girl presented with an aggressive giant-cell granuloma (GCG) of the maxilla with local invasiveness and bony destruction. The tumor recurred twice and attained a diameter of 6 cm. Previously, this patient had had two hematologic malignancies for which she had received therapeutic doses of radiation to the site where the GCG occurred. It is therefore possible that this tumor was radiation induced.

Adolescent↗
PubMed1989

Depletion of CD8+ cells in human thymic medulla results in selective immune deficiency.

CD8 molecules expressed on the surface of a subset of T cells participate in the selection of class I MHC antigen-restricted T cells in the thymus, and in MHC-restricted immune responses of mature class I MHC antigen-restricted T cells. Here we describe an immune-deficient patient with lack of CD8+ peripheral blood cells. The patient presented with Pneumocystis carinii pneumonia and was unable to reject an allogeneic skin graft, but had normal primary and secondary antibody responses. Examination of the patient's thymus revealed that the loss of CD8+ cells occurred during intrathymic differentiation: the patient's immature cortical thymocytes included both CD4+ and CD8+ cells while the mature medullary cells expressed the CD4 but not the CD8 protein on their surface. Northern blot and polymerase chain reaction analyses revealed the presence of CD8 alpha and beta mRNA in the patient's thymus but not in the peripheral blood. Both class I MHC antigen expression and the expressed TCR V beta repertoire are normal in this patient. These data are consistent with an impaired selection of CD8+ cells in the patient's thymus and support the role of the CD8 surface protein in thymic selection previously characterized in genetically manipulated and inbred mice.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1989

Abnormalities in the NC1 domain of collagen type IV in GBM in canine hereditary nephritis.

Samoyed hereditary glomerulopathy (SHG) in dogs serves as a model for human X-linked hereditary nephritis (HN). We previously showed that glomerular capillaries of affected males did not stain by immunofluorescence (IF) using serum from a patient with Goodpasture's syndrome. Our goal in the present study was to determine whether the NC1 domain of the collagen type IV molecule, which contains Goodpasture antigen (GPA), could be demonstrated in these dogs, and to assess its immunological reactivity. By SDS-PAGE, NC1 in collagenase digests of glomerular basement membranes (GBM) of unaffected and carrier female dogs in the family with SHG showed 24 kilodalton (kD), 26 kD and 28 kD monomer, and 46 kD and 47 kD dimer components, but the 24 kD monomer was diminished in the affected males. By IF, a rabbit antibody to NCl stained glomerular capillaries of unaffected, affected male, and carrier female dogs. In contrast, a human anti-GBM plasmapheresis fluid (PPF) stained glomerular capillaries of only the unaffected and carrier female dogs. By RIA, both antibodies reacted strongly with NCl in collagenase digests of GBM of the unaffected and carrier female dogs, but showed reduced reactivity with NCl of affected males. By Western blotting, both antibodies bound to dimers and 24 kD and 26 kD monomers of the NCl domain in collagenase digests of GBM of unaffected and carrier female dogs. However, in affected males, the rabbit anti-NCl antibody did not bind to the 24 kD monomer, while the human anti-GBM PPF showed weak binding to the 24 kD and 26 kD monomers.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

The NC1 domain of collagen type IV in neonatal dog glomerular basement membranes. Significance in Samoyed hereditary glomerulopathy.

Patients with hereditary nephritis (HN) present with renal disease after infancy, suggesting that the lesion of glomerular basement membranes (GBM) may not be congenital. Therefore, the NC1 domain of collagen type IV in normal neonatal dog GBM was compared with NC1 in normal adult GBM by SDS-PAGE and Western blotting, using two anti-NC1 antibodies. Similar results were obtained, indicating that the NC1 domain is present and immunoreactive in the neonatal period. Next, serial renal biopsies were performed on a family of Samoyed dogs with hereditary glomerulopathy (SHG), an animal model of HN, and assessed by immunofluorescence. One of the anti-NC1 antibodies produced global staining of GBM in unaffected dogs, and global/segmental staining in carrier females; however, no staining was seen in affected males as early as the neonatal period. Electron microscopy (EM) failed to demonstrate any lesion of GBM in neonatal dogs. Thus, in SHG, and presumably in human HN, the abnormality in the NC1 domain is congenital, and precedes the changes seen by EM in GBM.

Animals↗
PubMed1988

Primary Ewing's sarcoma of the orbit presenting with visual loss.

A case of primary Ewing's sarcoma of the orbit and paranasal sinuses in a 6-yearold boy is reported. The child presented with headaches and unilateral visual loss. Loss of vision as a result of optic nerve involvement with primary Ewing's sarcoma is extremely rare.

Blindness↗
PubMed1988

Characterization of glomeruli by immunohistochemistry and electron microscopy in a case of Wilms' tumor.

A patient with an abdominal mass was found to have a Wilms' tumor. Light microscopic examination showed that, in addition to blastema, stroma, and tubules, the tumor contained an unusually large number of glomeruli. Glomerular basement membranes stained positively by immunohistochemistry for laminin, collagen type IV, fibronectin, and Goodpasture antigen. Staining for Goodpasture antigen was seen only after acid-urea treatment, which was similar to findings in fetal and infant glomeruli. Glomerular cells stained positively for actin, myosin, and desmin, but there was no staining for factor VIII or Ulex europaeus agglutinin I, indicating an absence of endothelial cells. These findings were supported by electron microscopy, which showed basement membrane material, visceral epithelial cells, and mesenchymal cells (presumably primitive mesangial cells) in glomeruli, but no patent capillaries or capillary endothelium. Hence, the glomeruli in this case of Wilms' tumor were immature and also showed aberrant glomerulogenesis.

Female↗
PubMed1988

A sensitive method for immunocytochemical detection of P-glycoprotein in multidrug-resistant human ovarian carcinoma cell lines.

P-glycoprotein, a molecular weight 170 kilodalton membrane component can be accurately detected in a series of human ovarian carcinoma cells with increasing degrees of multidrug resistance by using a modified immunoperoxidase "sandwich" method. Drug-resistant derivatives were selected from a drug-sensitive parent ovarian carcinoma cell line, SKOV3, by continuous exposure to increasing concentrations of the cytotoxic drug vincristine. These cells had corresponding overexpression of P-glycoprotein demonstrable at both protein and mRNA levels. Monoclonal antibodies against P-glycoprotein localized staining for P-glycoprotein to the plasma membrane and the Golgi region in individual drug-resistant cells, in proportion to their P-glycoprotein expression. P-glycoprotein was not demonstrable in drug-sensitive SKOV3 cells by either immunoblotting or immunocytochemical staining methods. The immunocytochemical staining method allowed detection of P-glycoprotein in the least drug-resistant cell line with as low as 8-fold relative resistance to vincristine. This method is as sensitive as Northern blot, and more sensitive than standard Western blot in detection of P-glycoprotein. We conclude that this highly sensitive immunocytochemical staining method for P-glycoprotein can be suitable for determination of P-glycoprotein expression in biopsy samples of tumors, and it can be a powerful diagnostic and prognostic tool in the study of the natural history of drug resistance. This may have important applications in the clinical management of cancer chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1987

Cyclosporin A in children with persistent renal transplant rejection and progressively deteriorating graft function.

The effect on renal function and growth of switching from azathioprine to cyclosporin A (CyA) was prospectively evaluated in ten children with persistent renal transplant rejection. Progression of renal insufficiency during CyA therapy was compared with that before using CyA. Prednisone administration decreased after CyA was introduced and although growth retardation persisted, height velocity improved significantly. Renal function stabilized in seven patients treated with CyA for a variable time period, and four of these children remain off dialysis 0.44-1.42 years later. Renal biopsies were obtained in seven children when they were converted from azathioprine to CyA. The response to CyA could not be predicted from renal morphology or clinical features.

Adolescent↗
PubMed1987

Demonstration by light microscopy of cytomegalovirus on a renal biopsy of a renal allograft recipient: confirmation by immunohistochemistry and in situ hybridization.

A 14-year-old boy with end-stage renal failure secondary to reflux nephropathy received a renal transplant and was immunosuppressed with prednisone, azathioprine, and Minnesota antilymphoblast globulin, followed by cyclosporine A. A renal biopsy was performed 43 days post-transplantation because of fever and an elevated serum creatinine. The biopsy showed a mild interstitial lymphocytic infiltrate and immunosuppression was not changed. A second renal biopsy was performed 66 days after transplantation because of a persistent elevation of the serum creatinine following a cytomegalovirus (CMV) infection. CMV inclusions were seen by light microscopy (LM) in glomerular and peritubular capillary endothelial cells and tubular epithelial cells but no viral inclusions were present on the grids examined by electron microscopy (EM). However, the inclusions seen by LM were confirmed as CMV by immunohistochemistry, using polyclonal and monoclonal antibodies to CMV, and by in situ hybridization, using a biotinylated CMV DNA probe, emphasizing the usefulness of these techniques when studies by EM are not contributory.

Adolescent↗
PubMed1987

Samoyed hereditary glomerulopathy. Immunohistochemical staining of basement membranes of kidney for laminin, collagen type IV, fibronectin, and Goodpasture antigen, and correlation with electron microscopy of glomerular capillary basement membranes.

Recent immunofluorescence studies on the kidneys of most males with hereditary nephritis have demonstrated an absence of Goodpasture antigen (GPA) from glomerular capillary basement membranes (GCBM). In the present study, we used immunofluorescence to determine whether laminin, collagen type IV, fibronectin, and GPA could be detected in basement membranes of the kidneys of dogs with Samoyed hereditary glomerulopathy, which was previously shown to be a model for human hereditary nephritis. The results obtained were correlated with the appearance of GCBM by electron microscopy (EM). The rabbit polyclonal antibodies used (antilaminin, anti-collagen type IV, and antifibronectin) showed specificity for the appropriate antigens in a plate-binding radioimmunoassay. Serum from a patient with Goodpasture syndrome was used to detect the GPA component of dog GCBM. Laminin and collagen type IV were present in GCBM, mesangium, tubular basement membrane, vascular basement membrane, and Bowman's capsule of neonatal, unaffected, and affected male and carrier female dogs. Fibronectin was present in mesangial, perivascular, and interstitial regions of the kidneys of all dogs and, in addition, in GCBM of neonatal, affected male, and carrier female dogs. GPA was not detected in the kidneys of neonatal dogs and its absence from GCBM correlated with their immature appearance by EM. However, a fully formed, trilaminar GCBM was observed by 3 weeks of age in unaffected, affected male, and carrier female dogs, before the detection of GPA in GCBM, which occurred at 4 weeks in unaffected and carrier female dogs, but still not in affected males. In the unaffected dogs, the presence of GPA correlated with the persistence of a fully formed trilaminar GCBM, which lasted throughout life, while in the carrier females, the presence of GPA correlated with focal areas of multilaminar splitting of GCBM by EM. In the affected male dogs, although a trilaminer GCBM was seen by 3 weeks of age, the persistent absence of GPA correlated with the eventual onset of multilaminar splitting of GCBM. These immunofluorescence and EM results suggest that GPA is not required to form a trilaminar GCBM initially but is necessary subsequently to maintain its integrity. GPA is normally present in the C terminal (NC1) domain of the collagen type IV molecule. It is hypothesized that Samoyed hereditary glomerulopathy in dogs and human hereditary nephritis result from a defect in the NC1 domain.

Animals↗
PubMed1987

Samoyed hereditary glomerulopathy: serial, clinical and laboratory (urine, serum biochemistry and hematology) studies.

Human hereditary nephritis refers to familial glomerular diseases which may progress to renal failure. Samoyed hereditary glomerulopathy has been shown previously to be a model for hereditary nephritis. Clinical and laboratory studies were performed to follow progression to renal failure in 44 dogs in a family with Samoyed hereditary glomerulopathy. Affected males appeared healthy for their first three months but then became progressively wasted. Proteinuria was detected between two to three months of age; after five months, urine protein electrophoresis showed pre-albumin, albumin and alpha and beta globulin peaks. From three months onward, a reduced glomerular filtration rate was detected. Serum albumin decreased while amylase, urea, creatinine and phosphate increased from four to five months of age. Death from renal failure occurred by 15 months. Carrier females also became thinner and developed proteinuria between two and three months of age, but neither renal failure nor death ensured. Hence, SHG progressed rapidly in affected males but not in carrier females.

Animals↗
PubMed1986

Cyclosporine and experimental renal ischemic injury.

To investigate the interaction of cyclosporine nephrotoxicity and renal ischemia, an animal model in rats with bilateral renal artery clamping was used. Rats given cyclosporine had a lower rate of recovery from ischemia. However, the percentages of reduction in glomerular filtration rate in vehicle and cyclosporine groups were the same in sham-operated or ischemically treated group. This suggests a superimposition of cyclosporine nephrotoxicity on the recovering kidneys rather than synergistic potentiation between ischemia and cyclosporine nephrotoxicity.

Animals↗
PubMed1986

Focal adrenal hemorrhage: a new US appearance.

The ultrasonographic (US) appearance of neonatal adrenal hemorrhage has been described as a mass obliterating the normal contour of the entire gland. In the four cases described, different US appearances were found: In three, the hemorrhage was focal with the uninvolved portion of the gland visualized adjacent to the hemorrhage; in the fourth patient, hemorrhage involved primarily the medulla. Excellent computed tomographic or pathologic correlation with the US appearance was demonstrated. These findings suggest that adrenal hemorrhage should be considered in the differential diagnosis of focal adrenal masses in the neonate.

Adrenal Gland Diseases↗