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Biomedical subjects

U Helmchen

Publications and source records attributed to U Helmchen.

At least 73 records · Page 4Linked to original sources
PubMed1994

Treatment of atypical leishmaniasis with interferon gamma resulting in progression of Kaposi's sarcoma in an AIDS patient.

Visceral leishmaniasis (kala-azar) affecting HIV-infected patient is being reported in increasing frequency. A 40-year-old German bisexual patient with full-blown AIDS is described who presented with Kaposi's sarcoma, epigastric pain, diarrhea, and weight loss but without fever. Leishmania amastigotes were initially found in biopsies from stomach, duodenum, and a cutaneous Kaposi's sarcoma lesion but were later also recovered from bone marrow and lymph node. The patient received three courses of a combination of pentavalent antimony and interferon-gamma. In addition to the common side effects such as fever, thrombocytopenia, and elevated amylase and lipase, a vivid progression of the Kaposi's sarcoma was noted. Tumor progression was temporally closely associated with treatment with interferon-gamma. Because this phenomenon has also been observed in other patients, we advise caution when using interferon-gamma in patients with Kaposi's sarcoma.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Combination treatment of enalapril with nitrendipine in rats with renovascular hypertension.

We have recently shown that treatment with the calcium channel blocker nitrendipine may aggravate albuminuria and glomerular injury in rats with two-kidney, one clip renovascular hypertension if arterial blood pressure is not reduced. To test whether nitrendipine also exerts its adverse renal effects when normotension is achieved, we examined the effect of combined therapy with nitrendipine and the converting enzyme inhibitor enalapril on blood pressure, albuminuria, glomerular filtration rate, and morphology of the nonclipped kidney. Rats treated with enalapril alone or in combination with the diuretic hydrochlorothiazide or rats treated with nitrendipine alone served as controls. Therapy was started 6 weeks after clipping of one renal artery. Nitrendipine alone did not reduce blood pressure but significantly increased albuminuria, diuresis, glomerular filtration rate, and glomerular volume and injury compared with untreated hypertensive controls. Increase of glomerular filtration rate, diuresis, and albuminuria was reversible after withdrawal of nitrendipine. Treatment with enalapril alone decreased blood pressure significantly but not to normotensive levels and was without significant effect on albuminuria and glomerular morphology. The combination of nitrendipine and enalapril reduced blood pressure to normotensive levels and not only prevented the increase of glomerular volume, glomerular filtration rate, diuresis, and albuminuria caused by nitrendipine alone but furthermore improved glomerular injury and albuminuria to levels not significantly different from normotensive controls. Enalapril in combination with the diuretic had similar beneficial effects on blood pressure, albuminuria, and glomerular injury. These data demonstrate that the adverse effects of nitrendipine monotherapy on glomerular structure and function can be prevented by the combination of nitrendipine and enalapril when blood pressure is normalized.

Albuminuria↗
PubMed1994

Cyclosporin A nephropathy: standardization of the evaluation of kidney biopsies.

An advisory board of nephropathologists with personal experience in the evaluation of biopsies from patients treated with cyclosporin A (CyA) was set up to address the following problems: 1. Definition of CyA nephropathy as seen in patients with autoimmune diseases; 2. Evaluation of the reliability and reproducibility of the diagnostic criteria for the different morphological lesions seen in CyA nephropathy; 3. Classification of the morphological lesions according to their clinical relevance; 4. Estimation of the possible progression of CyA nephropathy with continuous CyA therapy. The most frequent lesions attributable to CyA therapy in patients with autoimmune diseases are tubular atrophy, interstitial fibrosis, and arteriolar hyalinosis. All other lesions are rare. The reproducibility and diagnostic reliability is high for tubular atrophy and interstitial fibrosis, but low for arteriolar lesions even among experienced nephropathologists. The biopsies may be classified according to the severity of tubular atrophy, interstitial fibrosis and arteriolar hyalinosis with regard to their clinical relevance: In group I (within normal limits), CyA therapy can be continued; in group III (moderate-to-severe CyA-related lesions), CyA should be stopped if possible. Among group II biopsies (slight CyA-related abnormalities), no recommendation can be made in the absence of a second biopsy after a further year of CyA therapy. No clear-cut answer can be given concerning the progression of CyA-induced lesions. However, no significant progression has been found in the cases studied to date.

Adolescent↗
PubMed1993

[Cyclophosphamide bolus therapy in lupus nephritis].

A pilot study of 21 patients (17 women; 4 men; mean age 35 [18-59] years), randomized into two groups, was undertaken to test how many cycles of intravenous pulse cyclophosphamide administration were required in lupus nephritis to achieve remission. It was planned that patients randomized to group A should be treated for 3 months, those in group B for over 12 months. In the first cycle the cyclophosphamide dosage was 500 mg/m2, in the subsequent cycles, 4 weeks apart, it was raised by 250 mg/m2 to a maximum of 1,000 mg/m2, if the WBC count was over 2,000/microliters. Three women in group B gave up treatment prematurely after 5-8 cycles, because a remission had occurred. In group A only one patient went into remission after only three cycles. Of the total of 18 patients in both groups whose data could be evaluated, 15 achieved remission after an average of 7.3 cycles and a cumulative total cyclophosphamide dosage of 9.3 g. The disease progressed in two patients, one died. No recurrence has so far been observed after a follow-up period of 1-41 months. Three patients had infections and two had developed leukopenia as side effects. Pulse cyclophosphamide has thus been shown to be an effective treatment in lupus nephritis, but it must be continued for more than 3 months.

Adolescent↗
PubMed1993

[Interstitial nephritis in typhus].

A 58-year-old man developed continuous fever of around 40 degrees C and a macular rash on the trunk and limbs one week after an eight-day visit to the island of Rhodos. Typhus was diagnosed on the basis of the clinical findings, the characteristic rash and a rise in antibody titre against Rickettsia prowazekii and mooseri (1:1280). The fever subsided and the patient's general state markedly improved within three days of starting antibiotic treatment with doxycycline. Five days after hospital admission renal function deteriorated, serum creatinine rising from 1.7 to maximally 8.7 mg/dl. Renal biopsy on the eighth day of illness revealed, in concordance with the diagnosis of a rickettsial infection, acute granulomatous interstitial nephritis. Doxycycline administration was continued for a total of 18 days and renal function improved. Two weeks after discharge serum creatinine had fallen to 1.8 mg/dl and to 1.2 mg/dl after 6 months. The antibody titre against Rickettsia prowazekii had fallen to 1:20 about 12 weeks after discharge. Early antibiotic treatment of typhus is of importance to avoid irreversible renal damage.

Antibodies, Bacterial↗
PubMed1993

Myocardial infarction in young patients with Hodgkin's disease--potential pathogenic role of radiotherapy, chemotherapy, and splenectomy.

Among a total of 2147 patients admitted to our hospital for acute myocardial infarction between 1978 and 1987, three young patients aged 24, 29, and 39 years had previously been treated for Hodgkin's disease. Staging laparotomy, including splenectomy, had been performed in all three patients. Two patients had both mediastinal irradiation (21 and 27 months before infarction) and chemotherapy. In the first patient, postmortem histologic examination of the coronary arteries revealed fibrotic changes, which were probably induced by radiotherapy. In our second patient, myocardial infarction developed 5 days after vinblastine treatment; early angiography showed thrombotic occlusion of the proximal right coronary artery, which was recanalized using the diagnostic Sones catheter. Subsequent angiography revealed normal coronary arteries. This is, to our knowledge, the first case of documented coronary artery thrombosis after treatment with vinca-alkaloids. In our third patient, neither mediastinal irradiation nor chemotherapy had been performed prior to myocardial infarction. However, a marked increase in platelet counts following splenectomy was observed in this patient. The role of radiotherapy, chemotherapy, and splenectomy with consecutive thrombocytosis as a third possible pathogenic factor for subsequent development of myocardial infarction is discussed.

Adult↗
PubMed1993

Increased expression of monocyte chemoattractant protein-1 in anti-thymocyte antibody-induced glomerulonephritis.

The infiltration of monocytes-macrophages in the glomerulus is one of the hallmarks of glomerulonephritis and may play an important pathogenetic role. Monocyte chemoattractant protein-1 (MCP-1) and colony stimulating factor-1 (CSF-1) are monocyte-specific cytokines with chemoattractant and activating activities for monocytes. MCP-1 and CSF-1 can be generated by several cell types, including glomerular mesangial cells, and can be stimulated by cytokines and immune complexes. To study the expression of CSF-1 and MCP-1 in a model of proliferative glomerulonephritis we used Northern blot analysis and immuno-histochemistry. The glomerular lesion was induced in rats by the i.v. injection of a heterologous anti-thymocyte antiserum (ATS), directed against an antigen which is localized on glomerular mesangial cells. Northern blot analysis revealed comparable amounts of CSF-1 in glomeruli isolated from control untreated rats, and from rats after 30 minutes to three weeks of injection of ATS antibody. In control glomeruli no mRNA levels for MCP-1 were detectable, but increased markedly 30 minutes after the induction of the nephritis, were then reduced at 24 hours and increased again at 5 and 21 days after induction of the disease. The increase in mRNA levels for MCP-1 30 minutes or 24 hours after ATS injection was markedly attenuated if rats were complement depleted by cobra venom injection. These time points following antibody injection were associated with mesangial immune complex formation (30 min), mesangiolysis (24 hr) and proliferative glomerulonephritis (5 and 21 days). By immunohistology the presence of MCP-1 was demonstrated in glomeruli with a predominant mesangial distribution. The mesangial immunofluorescence for MCP-1 followed a pattern similar to that of the mRNA for MCP-1 after induction of the disease process, that is, it increased after 30 minutes, decreased after 24 hours and was increased again at three weeks. Within 30 minutes of the antibody injection an increased infiltration of monocytes-macrophages was observed in the glomeruli, which was maintained up to three weeks of induction of the glomerulonephritis. When the rats were decomplemented with cobra venom factor prior to the i.v. injection of ATS, the expression of MCP-1 in glomeruli remained low and the influx of monocytes/macrophages did not appear. We conclude that MCP-1 is increased early on in glomeruli of rats with immune-mediated mesangial proliferative glomerulonephritis. This increase is mediated by complement activation secondary to the in situ immune complex formation at the glomerular mesangium.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

Glomerulonephritis associated with inflammatory demyelinating polyradiculoneuropathy: a case report and review of the literature.

A patient developed relapsing inflammatory demyelinating polyradiculoneuropathy associated with nephrotic syndrome. Renal biopsy showed focal-segmental glomerulosclerosis. The review of the literature disclosed that glomerulonephritis with and without nephrotic syndrome seems to be not uncommon in inflammatory demyelinating polyradiculoneuropathy, such as Guillain-Barré syndrome. membranous glomerulonephritis is the most frequent histologic diagnosis while minimal change nephropathy, 'acute glomerulonephritis' and postinfectious type glomerulonephritis are not often present. This is the first case of inflammatory demyelinating polyradiculoneuropathy associated with nephrotic syndrome due to focal-segmental glomerulosclerosis. Larger prospective studies are necessary and may contribute to the understanding of the pathogenesis of both, glomerulonephritis and inflammatory demyelinating polyradiculoneuropathy.

Adult↗
PubMed1992

[Interstitial lupus nephritis].

A 17-year old-male presented with a 6-week history of weight loss, lassitude and calf pains. On examination he was very pale. Laboratory tests showed a very high erythrocyte sedimentation rate (155 mm in the first hour), anaemia (haemoglobin 10.1 g/dl), and a raised serum creatinine of 1.54 mg/dl. Microhaematuria (5-10 erythrocytes/microliter) and pronounced pyuria (500 leucocytes/microliter) were present, but the urine was sterile and there was no increase in albumin excretion. The serum IgG was raised to 75.7 g/l, suggesting an autoimmune disorder. Anti-nuclear antibodies (titre 1 : 1920) and anti-double-stranded DNA antibodies (31 U/ml) were present, while the serum complement C4 was decreased to 0.11 g/l. Renal histology showed an interstitial nephritis without glomerular involvement, while the bone marrow showed vasculitis accompanied by a prominent plasma-cell infiltrate. A diagnosis of interstitial nephritis associated with systemic lupus erythematosus was made, with asymptomatic cardiac and hepatic involvement. Renal function recovered rapidly with prednisolone therapy (initial dose 2 mg/kg.d). While glomerulonephritis is the most common lupus-associated renal disorder, isolated interstitial nephritis may occur in some cases, often with an absence of proteinuria.

Adolescent↗
PubMed1992

Tubular function and histological findings in ifosfamide-induced renal Fanconi syndrome--a report of two cases.

Two patients developed renal Fanconi syndrome (RFS) after intensive long-term chemotherapy for metastatic Ewing sarcoma and disseminated neuroblastoma. Whereas RFS was diagnosed in patient 1 before he developed osteomalacia, patient 2 experienced severe rickets and growth retardation. Renal function studies revealed slight glomerular impairment and severe tubular defects leading to increased excretion of glucose, amino acids, inorganic phosphate and low molecular weight proteins, indicating proximal tubular damage. Patient 2 additionally showed distal tubular dysfunction with acidosis and diminished concentrating capacity. Renal biopsy in patient 1 revealed marked proximal tubular defects without interstitial lymphocytic infiltration. In both patients renal damage could most likely be ascribed to previous ifosfamide (IFOS) therapy. Our patients showed no improvement in renal function after cessation of IFOS treatment, indicating a poor prognosis of once established RFS after IFOS therapy. Measurement of tubular reabsorption capacities provides exact information on the extent of tubular toxicity induced by IFOS and may be used to monitor IFOS treated patients.

Adolescent↗
PubMed1992

Adverse effect of the calcium channel blocker nitrendipine on nephrosclerosis in rats with renovascular hypertension.

The effect of a 6-week treatment with the calcium channel blocker nitrendipine or the angiotensin converting enzyme inhibitor enalapril on blood pressure, albuminuria, renal hemodynamics, and morphology of the nonclipped kidney was studied in rats with two-kidney, one clip renovascular hypertension. Six weeks after clipping of one renal artery, hypertensive rats (178 +/- 4 mm Hg) were randomly assigned to three groups: untreated hypertensive controls (n = 8), enalapril-treated (n = 8), or nitrendipine-treated (n = 10). Sham-operated rats served as normotensive controls (128 +/- 3 mm Hg, n = 8). After 6 weeks of treatment, renal hemodynamics (glomerular filtration rate and renal plasma flow) were measured in the anesthetized rats. Renal tissue was obtained for determination of glomerular size and sclerosis. Enalapril but not nitrendipine reduced blood pressure significantly. After 6 weeks of therapy, glomerular filtration rate was not different among the studied groups. Renal plasma flow increased, but albumin excretion and glomerulosclerosis did not change after enalapril treatment. In contrast, in the nitrendipine-treated group albuminuria increased from 12.8 +/- 2 progressively to 163 +/- 55 compared with 19.2 +/- 9 mg/24 hr in the hypertensive controls. Furthermore, glomerulosclerosis index was significantly increased in the nitrendipine-treated group compared with the hypertensive controls (0.38 +/- 0.1 versus 0.13 +/- 0.04). In addition, glomerular size was higher in the nitrendipine-treated group (14.9 +/- 0.17 10(-3) mm2) but lower in the enalapril-treated group (11.5 +/- 0.15 10(-3) mm2) compared with the hypertensive controls (12.1 +/- 0.17 10(-3) mm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Albuminuria↗
PubMed1992

Morphologic and functional consequences of immune-mediated mesangiolysis: development of chronic glomerular sclerosis.

The i.v. injection of a rabbit anti-rat thymocyte serum (ATS) induces mesangiolysis in rats, followed by a mesangioproliferative glomerulonephritis (4 to 7 days after antibody). This proliferative lesion disappears 4 to 6 wks after antibody. In order to induce an antibody-mediated sclerotic glomerular disease, uninephrectomized rats received ATS twice at 6-wk interval. At 6 months after the first antibody injection, albuminuria, arterial blood pressure, and inulin clearances were evaluated and renal morphologic studies were performed. At the time of evaluation, mean arterial blood pressure and inulin clearances were not different between animals that received the antibody and uninephrectomized controls. Rats that were injected with antibody, however, had significantly higher albuminuria compared with that of controls. Glomeruli of rats with ATS revealed expansion of the glomerular mesangial matrix and focal sclerosis. A semiquantitative morphologic analysis revealed an increased incidence of glomerular lesions and a higher glomerular damage index in kidneys of nephritic rats. These data demonstrate that the repetitive injection of ATS to unilaterally nephrectomized rats induces a model of chronic glomerular sclerosis.

Albuminuria↗
PubMed1992

A rat model of progressive chronic glomerular sclerosis: the role of thromboxane inhibition.

In order to evaluate a possible role of thromboxane A2 (TxA2) in the pathophysiology of chronic glomerular disease, we studied the effect of a 12-wk combined treatment with the thromboxane receptor blocker Daltroban (D) and the thromboxane synthesis inhibitor UK 38485 (UK) on glomerular function and morphology in a rat model of chronic progressive glomerular injury. The glomerular lesion was induced in unilaterally nephrectomized rats by the repeated i.v. injection of an antibody directed against mesangial cells. Control rats were uninephrectomized. Three months after the first antibody injection before D and UK treatment, albuminuria (35.8 +/- 3.6 mg/24 h) and glomerular TxB2 formation (146 +/- 20 pg/mg of protein/min) were significantly higher compared with control values (albuminuria, 14.3 +/- 3.5 mg/24 h; TxB2, 59 +/- 16 pg/mg/min). Six months after antibody, albuminuria in nephritic rats had increased to 135 +/- 17 mg/24 h. In nephritic rats treated with D plus UK, albuminuria (44 +/- 12 mg/24 h), however, was significantly (P less than 0.001) inhibited. Quantitative morphological analysis (glomerular damage index) 6 months after antibody revealed significantly (P less than 0.001) increased glomerular lesions in nephritic rats (0.353 +/- 0.095) compared with that in uninephrectomized controls (0.045 +/- 0.014). The treatment of rats with D and UK significantly (P less than 0.001) reduced the glomerular damage index (0.101 +/- 0.004) in nephritic rats. D plus UK treatment reduced glomerular TxB2 formation but increased prostaglandin E2 and 6-keto prostaglandin F1 alpha release by isolated glomeruli. This study demonstrates that interventional treatment with D and UK ameliorates albuminuria and glomerular morphological lesions in a rat model of immunologically induced progressive glomerular injury.

Albuminuria↗
PubMed1992

Cytomegalovirus detection in kidney transplants: results obtained from the polymerase chain reaction.

Kidneys from twelve renal transplant recipients were examined prior to and after graft failure and explantation. The investigations included conventional light and electron microscopy and the analysis of human cytomegalovirus-related viral proteins and viral DNA. Nucleic acid hybridization studies were conducted on kidney explants by an in situ method using DNA probes and by the polymerase chain reaction employing primers and probe for immediate early gene targets. In none of the cases did light and electron microscopy including immunohistochemistry for human cytomegalovirus reveal active infection in punch biopsies or explants. Interestingly, in situ hybridization also failed to detect human cytomegalovirus even in two cases with seroconversion, while the polymerase chain reaction was positive. The polymerase chain reaction disclosed only two additional positive cases within the residual group of explanted kidneys. In our hands, the polymerase chain reaction was the only potent direct detection method for cytomegalovirus in transplanted human kidneys.

Adult↗
PubMed1992

Kidney transplantation in Alport's syndrome: long-term outcome and allograft anti-GBM nephritis.

Anti-glomerular basement membrane (anti-GBM) nephritis occurring in kidneys transplanted in patients with Alport's syndrome (AS) has been reported repeatedly. Therefore, we studied graft survival and course of renal function in all 30 AS patients grafted at Hannover Medical School and compared them with non-diabetic, age and sex matched patients, transplanted on the date closest to the transplantation of the AS patient. Serum creatinine, proteinuria, urinary sediment and anti-GBM antibodies were examined in all AS patients with functioning grafts. Cases of patient or graft loss in the AS group were analyzed retrospectively. One- and five-year patient survival was 100 and 91% in AS and 89 and 78% in controls (p > 0.05, respectively). One- and five-year first graft survival was 79 and 66% in both groups. Graft histology was available in 34 biopsies obtained from 21 kidneys in 15 AS patients. Anti-GBM nephritis was not detected in any of the biopsies. No graft was lost due to anti-GBM nephritis. Anti-GBM antibodies were detectable temporarily only in one AS patient. He also had linear IgG staining in his graft GBM, but no other signs of anti-GBM nephritis. We conclude that patient survival and graft survival in AS patients following kidney transplantation is not different from non-AS patients. Allograft anti-GBM nephritis is a rare complication in patients with Alport's syndrome.

Adult↗
PubMed1991

[Anti-basal membrane glomerulonephritis after homologous kidney transplantation in hereditary Alport's nephropathy].

A patient, born in 1968, was found at the age of 9 years to have Alport's syndrome. In his 20th year, when in terminal renal failure, his father's kidney was transplanted into him. 14 months later there was a sudden worsening of his renal function after a varicella infection; for the first time antibodies against the glomerular basal membrane (GBM) were detected. Despite an increase in prednisolone dosage and 6 plasmaphereses chronic haemodialysis again became necessary. Renal biopsy revealed necrotizing intra- and extracapillary glomerulonephritis. Simultaneously there was a raised anti-NC-1-antibody titre (1:80) in the serum. After removal of the transplant the titre fell to normal. The NC-1 antigen, a component of the GBM in healthy persons, may be absent in Alport's syndrome. An analysis of the few cases of anti-GBM glomerulonephritis in renal transplants of patients with Alport's syndrome may make it possible to recognize factors which precipitate or favour this form of glomerulonephritis.

Adult↗