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Biomedical subjects

G H Thoenes

Publications and source records attributed to G H Thoenes.

At least 19 recordsLinked to original sources
PubMed2002

A case of idiopathic nodular glomerulosclerosis mimicking diabetic glomerulosclerosis (Kimmelstiel-Wilson type).

A case of idiopathic nodular glomerulosclerosis mimicking diabetic Kimmelstiel-Wilson glomerulopathy is reported. The patient was a 45-year-old man suffering from nephrotic syndrome. Light and electron microscopy revealed diffuse and nodular glomerulosclerosis indistinguishable from diabetic nodular glomerulosclerosis. Diabetes mellitus, however, had been excluded both by extensive clinical and by laboratory investigation. The differential diagnosis also included amyloidotic and non-amyloidotic fibrillary glomerulopathy, light chain glomerulopathy, collagen type III disease, immunotactoid glomerulopathy, and the sclerosing variant of membranoproliferative glomerulonephritis. Immunohistochemistry and ultrastructural investigations, however, excluded these entities, and the diagnosis of idiopathic nodular glomerulosclerosis was made. This variant has to be included in the differential diagnosis of nodular glomerulopathy associated with nephrotic syndrome.

Amyloidosis↗
PubMed1998

[Chronic HIV- and chronic HBV infection with hematuria and proteinuria].

HISTORY AND CLINICAL FINDINGS: A medical examination, undertaken in an apparently healthy 30-year-old man because of his occupational exposure to chemicals, revealed haematuria and proteinuria. Physical examination was unremarkable except for oral hair-leukoplakia and swelling of the cervical, supraclavicular, axillary and inguinal lymph nodes. INVESTIGATIONS: Examination of the urine demonstrated selective glomerular proteins (1.5 g/24 h) and dysmorphic erythrocytes. SGOT and SGPT activities were raised (73 and 129 IU/l, respectively). Active hepatitis B virus (HBV) and human immunodeficiency virus (HIV-1) infections were demonstrated virologically. The CD4+ count in blood was reduced to 200 cells/microliter. Renal biopsy showed an IgA nephropathy. TREATMENT AND COURSE: Antiretroviral treatment with zidovudine and lamivudine were started. SGOT and SGPT activities and HIV load fell steadily, while CD4+ cell count rose markedly. Renal functions have remained stable during the past 6 months. CONCLUSION: Signs of glomerular damage are not unusual in systemic diseases, tumors or infections (Hepatitis B and HIV in this case) and they may be the first manifestations of the underlying disease.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Distribution of the granulocyte serine proteinases proteinase 3 and elastase in human glomerulonephritis.

The serine proteinases proteinase 3 (PR3) and elastase are target antigens of antineutrophil cytoplasmic autoantibodies (ANCAs), which are found in various systemic vasculitides with rapidly progressive glomerulonephritis (RPGN). The expression of both proteinases was studied immunohistologically (avidin-biotin complex method) with murine monoclonal antibodies against PR3 (WGM2) and elastase (NP 57) in 122 human renal biopsy specimens to investigate their role in mediating renal damage. Expression of PR3 predominated in ANCA-associated RPGN and was independent of the serologic ANCA pattern (c-/p-ANCA). The PR3 staining pattern was patchy and not always related to distint granulocytes due to antigen spreading by disintegrating cells. It was found in crescentic glomeruli and the interstitum of ANCA-positive RPGN. In contrast, glomerular and interstitial elastase staining pattern was much more granulocyte related and was even found in noncrescentic glomeruli in c-ANCA- and p-ANCA-positive pauci-immune RPGN. Endothelial cell and glomerular basement membrane-bound PR3 or elastase expression were not observed. A faint glomerular PR3/elastase expression was seen in Goodpasture's syndrome and within the interstitium in crescentic mesangioproliferative glomerulonephritis (granulocyte related). Both serine proteinases were found in the glomeruli in ANCA-negative acute postinfectious glomerulonephritis. In conclusion, this study provides evidence, for the first time, for the implication of the granulocyte serine proteinases PR3 and elastase in mediating pauci-immune ANCA-positive RPGN and different forms of proliferative glomerulonephritis. The expression of ANCA antigens in ANCA-negative glomerulonephritis suggests that this finding is a marker of neutrophil activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1994

Prevention of the acute graft-versus-host disease (GVHD) in rats by the immunomodulating drug leflunomide.

The grafting of immunocompetent allogeneic cells into MHC-discordant, genetically nonresponsive F1 hybrids of inbred rat strains consistently leads to an acute, lethal graft-versus-host disease (GVHD). The novel immunomodulating drug leflunomide, which has been shown to be efficacious in animal models of autoimmunity and adverse transplantation reactions, was studied in a rat model of GVHD. It was found that this drug not only was a powerful agent to prevent this otherwise terminal disorder, but was also proficient when used as a therapy of an established GVHD. Since leflunomide has been shown to be efficacious and safe in patients with chronic rheumatoid arthritis, it would also be reasonable to investigate this drug in clinical trials for bone marrow transplantation and GVHD in human beings.

Acute Disease↗
PubMed1991

Leflunomide (HWA 486), a novel immunomodulating compound for the treatment of autoimmune disorders and reactions leading to transplantation rejection.

Leflunomide has been shown to be very effective in preventing and curing several autoimmune animal diseases. Further, this agent is as effective as cyclosporin A in preventing the rejection of skin and kidney transplants in rats. Preliminary results from patients suffering from severe cases of rheumatoid arthritis demonstrated that clinical and immunological parameters could be improved with leflunomide therapy. Mode of action studies revealed that this substance antagonizes the proliferation inducing activity of several cytokines and is cytostatic for certain cell types. In this light, we could show that tyrosine phosphorylation of the RR-SRC peptide substrate and the autophosphorylation of the epidermal growth factor (EGF) receptor were, dose dependently, inhibited by leflunomide. EGF activates the intrinsic tyrosine kinase of its receptor, which stimulates the phosphorylation of a variety of peptides, the amino acid residue in all cases is tyrosine. These results indicate that much of leflunomide's activity could be due to the inhibition of tyrosine-kinase(s), which is an important general mechanism for the proliferation of various cell types. Thus, leflunomide, which is effective against autoimmune diseases and reactions leading to graft rejection, would seem to have a mode of action separating it from known immunosuppressive drugs.

Amino Acid Sequence↗
PubMed1989

Spontaneous immune complex orchitis in brown Norway rats.

Immune complexes occur spontaneously in the testis of Brown-Norway (BN) inbred rats between the basal lamina of the seminiferous tubules and the outer lamina of the myoid testicular cells. The deposits can be detected immunohistologically (IgG; C3) and by electron microscopy. The immune complexes appear between the 8th and 12th weeks of life, increase in amount up to the 30th week and decrease thereafter. After about the 20th week, of life, 15% of the animals show destruction of the germinal epithelium accompanied by an infiltration of lymphocytes and plasma cells. The final stage of this disease, which initially shows no signs of inflammation, is characterized by diffuse tubular atrophy. However, up to the 70th week of life, 85% of the animals with immune complexes show no pathological alterations. Antibodies eluated from the testes react with spermatocytes I and structures close to the lumen of the seminiferous tubules, but not with mature sperms. Serum antibodies to sperms occur in about 25% of the BN rats, but the presence of these antibodies shows no correlation with the immunohistological findings. This newly described spontaneous immune complex orchitis is regarded as a further example of an in-situ-induced immune complex disease. The observations made here can be compared with those in (peri-) membraneous glomerulonephritis, another example of a disorder resulting from in-situ-formation of immune deposits.

Animals↗
PubMed1989

Leflunomide (HWA 486) inhibits experimental autoimmune tubulointerstitial nephritis in rats.

Experimental tubulointerstitial nephritis (TIN), induced in Brown Norway rats, is an autoimmune disorder in which afflicted animals display high levels of serum autoantibodies directed against antigens present on the tubular basement membrane (TBM). Serious functional damage, due to lesions of the kidney cortex, is evident 10 days after disease initiation. In an earlier study, we could show that cyclosporin A (CsA), an immunosuppressive drug, effectively prevented the onset of this illness, although it did not inhibit the formation of TBM autoantibodies. In the present study, the protective effects of CsA in autoimmune TIN was compared to those of drugs currently used to combat inflammatory ailments (i.e. prednisolone, indomethacin, naproxen, azathioprine) and a novel immunomodulating agent, leflunomide (HWA 486). Leflunomide is known to specifically inhibit the formation of T-dependent antibodies and is effective in preventing and curing animal autoimmune diseases, i.e. adjuvant arthritis disease of rats and murine lupus-like disorders. We found that not only could leflunomide inhibit TIN, but the drug-effects seemed to be more effective than those of CsA. Further, leflunomide was extremely effective in inhibiting the formation of autoantibodies to TBM, whereas CsA displayed only partial suppression. Neither prednisolone, indomethacin nor naproxen were effective in reducing the autoantibody titer, and did not offer any protection to the development of this disease. Together with the known effects on other autoimmune diseases we conclude that leflunomide is a novel immunointerventive drug protecting against several types of autoimmunity.

Animals↗
PubMed1989

[The value of immunofluorescence on frozen sections and immunoperoxidase methods on paraffin sections with different types of glomerulonephritis comparative study].

171 kidney biopsies were tested with the peroxidase- antiperoxidase (PAP)-method on paraffin sections. A comparison of the PAP-results with corresponding ones for the immunofluorescence method (IMF) on frozen sections was possible in 131 of the biopsies. When results of the 2 techniques were compared, outcomes showed a very strong accordance for both methods in tissues of postinfectious and perimembraneous GN an a strong accordance in mesangioproliferative GN tissue. In membrano-proliferative GN the immunopathological findings were more readily delinated with the PAP-method than with IMF. Cases involving IgA-nephritis, focal sclerosis and lupus nephritis with smaller deposits did not show consistant reactivity in the PAP-method as compared with IMF. 40 kidney biopsies, not examined by IMF, were diagnosed as GN by light microscopy and could be shown in 29 cases to contain evidence of an immune pathogenesis with the PAP-method.

Biopsy↗
PubMed1987

Cyclosporin A inhibits autoimmune experimental tubulointerstitial nephritis.

Tubulointerstitial nephritis, regularly induced in Brown Norway rats by autosensitization with tubular basement membranes, appeared acutely at about 10 days and was completely inhibited by Cyclosporin A (CyA) when this was given before and at the time of onset of the disease. It did not recur after the end of therapy. In spite of this disease inhibition, autoantibodies against tubular basement membranes persisted in the circulation and in the kidney. It is therefore suggested that it is not so much the antibodies that are the decisive factors in the pathogenesis of this and other autoimmune diseases but, rather cellular factors that are directly influenced by CyA. Although in this model CyA application was a preventive measure, the experiments provide a cogent reason for the application of CyA as early as possible in acute and seriously damaging diseases.

Animals↗
PubMed1987

[Kidney biopsy].

Explore the source record for details and available documents.

Biopsy↗
PubMed1987

Follow-up studies of three subtypes of acute postinfectious glomerulonephritis ascertained by renal biopsy.

Quantitative correlative investigations by means of light, immunofluorescence and electron microscopy carried out in the early phase of the disease on 58 patients (children and adults) with acute postinfectious glomerulonephritis (APGN) formed the basis of subtyping APGN into a starry sky type, a mesangial type and a garland type [Sorger et al. 1982 and 1983]. The subtypes also showed differences in the clinical picture. The garland type was of special interest since most patients had severe proteinuria. This caused us to follow-up the patients with these three subtypes (up to 10 years and 7 months). Proteinuria proved to be the most reliable follow-up parameter. A comparison of the three groups showed that proteinuria rapidly declined as a rule in the patients with the starry sky and the mesangial patterns. In the garland pattern there were also cases with a complete disappearance of proteinuria, especially in younger patients, but other patients still had a distinct proteinuria after months to years indicating a protracted or chronic course. The morphological findings of the rebiopsies correlated with the clinical courses, especially with the course of proteinuria. The three morphological subtypes are thus significant for estimating the prognosis of APGN, which is favorable as a rule in patients with the starry sky and mesangial types, but much more unfavorable in patients with the garland type. Even if fewer cases with demonstrated streptococcal etiology were found in the garland pattern group, i.e., among patients with the most uncertain prognosis, than in the remaining groups, these differences were not statistically significant. Therefore, our investigations do not provide any indications that different etiological factors are responsible for the three subtypes. The individual immune response of the host body is likely to be very much more decisive.

Acute Disease↗
PubMed1985

[Recurrent pulmonary hemorrhage with normal kidney function].

A case of Goodpasture's syndrome with normal renal function is described. Clinical, morphological and prognostic features of the diagnosis are compared with the findings in Goodpasture's syndrome with progressive renal failure and with the findings in idiopathic pulmonary hemosiderosis.

Adult↗