Pathological profiles of systemic infections by Panton-Valentine leukocidin-positive, methicillin-resistant Staphylococcus aureus strains in a murine model.

AIMS: Staphylococcus aureus is one of the most common pathogens in hospital environment and community. Panton-Valentine leukocidin (PVL) production is clinically associated with skin abscesses, soft tissues infections, bacteraemia and sepsis. This study aimed to investigate the effects of the presence of genes lukF/S-PV coding for PVL, in histological and haematological features during systemic infection, using a Swiss mice experimental model. METHODS AND RESULTS: Experiments were performed using 25 mice distributed into five experimental groups, intravenously inoculated with 50 µl suspensions at density 1·0 × 107  CFU per ml of strains: methicillin-susceptible (MSSA) and pvl-negative strains isolated from nasal colonization; MSSA pvl-positive strains isolated from nasal colonization; methicillin-resistant (MRSA) and pvl-positive strains isolated from peripheral blood of a patient with severe pulmonary infection; and a MRSA pvl-positive strains isolated from a peripheral blood culture of a patient with bacteraemia. Haematological analysis was performed at 24, 48, 72 and 96 h post-infection. Morphoanatomy and histopathological analyses were performed at 96 h post-infection. For all S. aureus strains tested, the capability of intravenous dissemination and survival into mice tissues was demonstrated. Inflammatory processes at different levels were related to the presence of pvl genes, and included alterations in the format, size and colour of the organs. Staphylococcus aureus pvl-positive strains were detected in greater numbers in the organs of the infected animals. CONCLUSIONS: The pvl-positive strains isolated from blood cultures were capable to induce the greatest modifications in both haematological and histopathological profiles, and seemed to aggravate the systemic infections. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings are valuable in characterizing infections caused by S. aureus in humans and murine.

Polysaccharide-based aerogel microspheres for oral drug delivery.

Polysaccharide-based aerogels in the form of microspheres were investigated as carriers of poorly water soluble drugs for oral administration. These bio-based carriers may combine the biocompatibility of polysaccharides and the enhanced drug loading capacity of dry aerogels. Aerogel microspheres from starch, pectin and alginate were loaded with ketoprofen (anti-inflammatory drug) and benzoic acid (used in the management of urea cycle disorders) via supercritical CO2-assisted adsorption. Amount of drug loaded depended on the aerogel matrix structure and composition and reached values up to 1.0×10(-3) and 1.7×10(-3) g/m(2) for ketoprofen and benzoic acid in starch microspheres. After impregnation, drugs were in the amorphous state in the aerogel microspheres. Release behavior was evaluated in different pH media (pH 1.2 and 6.8). Controlled drug release from pectin and alginate aerogel microspheres fitted Gallagher-Corrigan release model (R(2)>0.99 in both cases), with different relative contribution of erosion and diffusion mechanisms depending on the matrix composition. Release from starch aerogel microspheres was driven by dissolution, fitting the first-order kinetics due to the rigid starch aerogel structure, and showed different release rate constant (k1) depending on the drug (0.075 and 0.160 min(-1) for ketoprofen and benzoic acid, respectively). Overall, the results point out the possibilities of tuning drug loading and release by carefully choosing the polysaccharide used to prepare the aerogels.

[The Ontario Domestic Assault Risk Assessment (ODARA) - Validity und authorised German translation of an intimate partner violence screening tool]. / Das Ontario Domestic Assault Risk Assessment (ODARA) - Validität und autorisierte deutsche Übersetzung eines Screening-Instruments für Risikobeurteilungen bei Intimpartnergewalt.

On average one third of all women are victimised by intimate partner violence at least once in their life. Many women are affected repeatedly. To efficiently reduce the risk of repeated violence a reliable and valid risk assessment is needed. To date several risk assessment tools have been published in the field of intimate partner violence. There is a strong demand for such tools to be applicable by a wider range of practitioners (e.g., police officers, hospital and victim services' staff) to reliably assess cases of intimate partner violence and recommend further interventions. By developing the Ontario Domestic Assault Risk Assessment (ODARA) it was the authors' aim to provide a brief risk assessment tool which can be scored on the basis of only few and easily collectable information and which efficiently discriminates between low-risk and high-risk offenders of intimate partner violence. Previous replication studies found moderate to good and on average higher power of discrimination of the ODARA compared to other risk assessment tools in the field. However, for the German speaking countries robust findings are still lacking. In the present publication a scientific and authorised translation of the ODARA is provided.

[Renal manifestations of light chain associated diseases - epidemiology and prognosis]. / Renale Manifestationen von Leichtkettenerkrankungen - Epidemiologie und Prognose.

BACKGROUND: An impaired renal function in light chain associated disorders may be caused by myeloma cast nephropathy (MCN) but also by AL-amyloidosis (AL-A) and monoclonal immundeposition disease (MIDD). PATIENTS AND METHODS: In a monocentric, retrospective analysis, patients suffering from multiple myeloma (MM) (n = 392) requiring medical therapy, AL-A (n = 53) or MIDD (n = 12) diagnosed between 1996 and 2008 were evaluated for renal insufficiency. The different patient cohorts were compared in terms of their clinical course and outcome. RESULTS: Renal insufficiency in MM-, AL-A- or MIDD-patients at the time of diagnosis was found in 45,5 % of the patients. MCN, AL-A and MIDD were found in 68, 25 and 6 %, respectively. Dialysis dependency was seen in 17 % of MCN, in 8 % of AL-A and in 50 % of MIDD patients. Signs of hypervolemia were the leading symptoms in MIDD/AL-A. The time between the occurence of first symptoms and diagnosis was as long as 52 weeks in patients with AL-A. Patients with renal involvement showed a reduced median survival of 17 compared with 77 months in patients with a normal renal function. Median survival was only 12 months in AL-A compared to 21 months in MCN. Stabilization of renal function after chemotherapy occurred only in MCN. Multivariate Cox regression analysis showed impaired renal function as independent risk factor (Hazard-Ratio 2,88 [2,06-4,0]. In terms of survival and kidney function, autologous stem cell transplantation (ASCT) was beneficial for patients with renal involvement. CONCLUSION: Renal insufficiency is an independent risk factor in MM, AL-A and MIDD. Specific therapy, especially ASCT may improve prognosis in patients with renal insufficiency and could stabilize renal function in MCN-patients.

An Empirical Model of Slope Ratio Comparisons.

Comparing slopes is a fundamental graph reading task and the aspect ratio chosen for a plot influences how easy these comparisons are to make. According to Banking to 45°, a classic design guideline first proposed and studied by Cleveland et al., aspect ratios that center slopes around 45° minimize errors in visual judgments of slope ratios. This paper revisits this earlier work. Through exploratory pilot studies that expand Cleveland et al.'s experimental design, we develop an empirical model of slope ratio estimation that fits more extreme slope ratio judgments and two common slope ratio estimation strategies. We then run two experiments to validate our model. In the first, we show that our model fits more generally than the one proposed by Cleveland et al. and we find that, in general, slope ratio errors are not minimized around 45°. In the second experiment, we explore a novel hypothesis raised by our model: that visible baselines can substantially mitigate errors made in slope judgments. We conclude with an application of our model to aspect ratio selection.

[The Sex Offender Risk Appraisal Guide (SORAG)]. / Der Sex Offender Risk Appraisal Guide (SORAG).

In North America, the use of actuarial instruments is considered to be state of the art in the assessment of offender recidivism risk. One of these instruments is the "Sex Offender Risk Appraisal Guide" (SORAG), which was developed specifically for the use in sex offender risk assessment. The present review investigates the current state of knowledge regarding the instrument's validity specifically for its use in German-speaking countries. Overall the results speak for the instrument's good discriminatory power. However, this is not true to the same degree for all types of sex offender populations. The discriminatory power is especially good in the subpopulation of child molesters. Part of the present review is a German translation of the instrument authorised by the developers of the SORAG.

Are tissue samples from two different anatomical areas of the kidney necessary for adequate diagnosis?

BACKGROUND: An accurate histological diagnosis is of fundamental importance for the therapy and prognosis of many kidney diseases. However, it remains unclear whether a single biopsy is representative of changes in the whole kidney. METHODS: To compare the quantity and quality of renal biopsy material taken from two separate areas from one kidney, we prospectively biopsied the renal cortex at the central third and at one of the kidney poles of 103 consecutive 61 native and 42 transplanted kidneys. With two biopsy cores from each kidney we sampled 14.5 ± 8.5 glomeruli/procedure. RESULTS: The length of the biopsy core, the number of glomeruli/core and the markers of chronic renal damage (degree of interstitial fibrosis, proportion of global or segmental scared glomeruli) were not influenced by biopsy location (pole compared with central third locations). Moreover, there was no significant difference in the number of arteries in biopsies obtained from the two different biopsy areas. The percentage between renal cortex and medulla was not influenced by the biopsy area in all kidneys, but transplanted kidney biopsies contained more medulla than specimens from native kidneys. In patients with native kidneys and lower estimated creatinine clearances, there was a nonsignificant trend towards higher variations in the degree of interstitial fibrosis between the two cores, but a coincidence cannot be excluded. There was no significant difference in global sclerotic glomeruli in regard to the biopsy location. CONCLUSION: We conclude that a renal biopsy composed of two cores from different areas of the kidney provides enough material for histological diagnosis. However, despite the variety of different renal diseases, sampling errors are minimal and obtaining two biopsies from different areas of the kidney does not lead to clinically useful information which would alter the management of patients.

[Prison violence: prevalence, manifestation and risk factors]. / Gewalt im Strafvollzug: Prävalenz, Erscheinungsformen und Risikofaktoren.

When comparing different studies on prison violence, it must be taken into account that correctional facilities vary considerably among one another. Studies conducted in Switzerland have shown that every one inmate in four is violent at least once during incarceration. These violent acts differ in regard to manifestation and a specific characterization of violence according to type, target, implication and trigger appears to be necessary. Existing criminal prognostic instruments are not suitable for estimating the risk of violent behavior in prisons. Therefore, the development of specific models is essential. International studies have identified various risk factors. However, due to the aforementioned differences in facilities, these predictors can only partly be transferred to a Swiss setting.

Evolution of light chain deposition disease over 8 years.

A 44-year-old female was diagnosed with proteinuria due to nodular glomerulosclerosis secondary to light chain deposition disease (LCDD). After 6 years, deterioration of kidney function occurred and autologous stem cell transplantation was considered, but the patient refused specific therapies. The disease progressed slowly, over a period of 8 years reaching now chronic renal insufficiency stage 4 with a creatinine clearance of 20 ml/min, in spite of no specific therapy. This case, documented by repeated biopsies, demonstrates the very slow loss of kidney function, suggesting the possibility of conservative treatment strategies without taking the risks of chemotherapy or autologous stem cell transplantation, since no long term follow up data of these therapies are available for LCDD.

"Nearly a stairway to heaven"--severe dichromate intoxication in a young man.

A 22-year-old man presented with dichromate intoxication in a suicidal attempt. He exhibited signs of liver and renal toxicity and very high serum chromium levels. Since it has been reported in the literature that hemodialysis and hemoperfusion are not sufficient to remove chromium, we tried plasmapheresis considering the fact that chromium salts bind to protein. Five plasmapheresis treatment sessions significantly lowered his serum and urinary chromium concentrations. The patient survived without organ damage despite ingestion of a lethal dichromate dose and high serum chromium concentration. Thus, plasmapheresis should be considered as a potential therapeutic option to reduce chromium concentrations.

A single-center experience with BK virus nephropathy.

BACKGROUND: BK virus nephropathy has an increasing role in renal transplant dysfunction, since new, highly potent immunosuppressive drugs have been introduced into therapy following renal transplantation. Diagnosis of acute impairment of renal transplant function is complicated by difficulty in differentiating BK virus nephropathy from acute rejection. PATIENTS AND METHODS: We retrospectively described the findings and therapeutic approaches of 6 consecutive patients with BK virus nephropathy in our transplantation center (75 - 80 transplantations/ year). BK virus nephropathy was classified according to Drachenberg et al. [2004]. RESULTS: We observed an incidence rate of < 1% for BK nephropathy in our center. Four patients had a pattern B whereas 2 patients revealed a pattern C of BK virus nephropathy. Focal C4d-positive staining of peritubular capillaries were found in 2 of the 6 cases. For earlier detection of BK nephropathy, a diagnostic algorithm for each patient after renal transplantation was established. Urine was continuously monitored by cytology for decoy cells and PCR for BK virus DNA. If PCR was also positive for the BK virus in plasma, biopsy of the renal allograft was performed. Thereby diagnosis could be confirmed sooner. For treatment of BK nephropathy in our center, we reduced immunosuppressive agents and initiated a virustatic treatment with cidofovir in the first 3 cases. However, results were not satisfactory and two allografts were lost. We then reconsidered our therapeutic approach and switched the immunosuppressive treatment to leflunomide with consistent low dose steroids. We use therapeutic drug monitoring for leflunomide and aim at a target level of 40 - 100 microg/ml. We lost no allograft with BK nephropathy since using this therapeutic approach. CONCLUSION: In our center, leflunomide therapy, but not cidofovir, was effective in patients with BK virus nephropathy of the renal allograft.

Collagen type VIII expression in human diabetic nephropathy.

BACKGROUND: Collagen type VIII is a non-fibrillar short-chain collagen that may modulate migration, proliferation and adherence of various cells. Only very sparse information exists on collagen type VIII expression in human diabetic nephropathy. MATERIAL AND METHODS: We retrospectively studied mRNA expression for the two collagen type VIII chains (COL8A1 and COL8A2) in 20 biopsies with histologically confirmed diabetic nephropathy by real-time PCR, and compared glomerular and tubular expression with normal kidney [pre-transplant biopsies (n = 10)]. Expression of collagen type VIII was also studied in biopsies from patients with benign nephrosclerosis (BNS; n = 16) and focal-segmental glomerulosclerosis (FSGS; n = 9). RESULTS: A strong specific induction of COL8A1 mRNA was found in diabetic nephropathy in both glomerular and tubular compartments. There was also a robust induction of COL8A2 in diabetic nephropathy, but overall expression was lower than that of COL8A1 transcripts. No significant increase in COL8A1 and COL8A2 mRNAs expression was found in biopsies from patients with BNS and FSGS compared with normal kidneys. The cross-reactivity of the used anti-alpha1(VIII) antibody with human tissue was confirmed by Western blots. Immunohistological analysis revealed only little staining for collagen type VIII in the normal kidney, localized to vessels. There was an up-regulation of collagen type VIII protein expression as shown by immunohistochemistry in the diabetic nephropathy biopsies mainly localized to mesangial cells, tubules and the interstitium. Proteinuria and serum creatinine did not correlate with glomerular or tubular COL8A1 and COL8A2 mRNA expression in diabetic patients. CONCLUSION: Our study systemically investigates collagen type VIII expression in human biopsies. Induction of collagen type VIII was specific for diabetic nephropathy and did not occur in the other renal diseases studied. More specific factors of the diabetic environment are likely involved in the stimulated expression because there was no correlation of collagen type VIII mRNA expression with proteinuria. Since collagen type VIII may influence proliferation and migration of cells, it is possible that an increase in renal expression of collagen type VIII initiates other pathophysiological processes (e.g. proliferation of renal fibroblasts) involved in diabetic nephropathy.

Thrombotic microangiopathy in a 17-year-old patient: TTP, HUS or a bit of both?

Thrombotic microangiopathies are characterized by the development of hyaline thrombi in small vessels resulting in thrombocytopenia, microangiopathic hemolysis, and organ dysfunction. Thrombotic-thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are two major clinical syndromes of thrombotic microangiopathies. Although differential diagnosis between TTP and HUS is commonly determined in the clinical setting, recent evidence suggests major pathophysiological differences between the two diseases. Autoimmune inhibitors or genetic mutations of a von Willebrand factor (VWF) cleaving metalloprotease (ADAMTS13) leads to the accumulation of unusually large multimeric forms of VWF in TTP, facilitating adherence of platelets and development of microthrombi. In contrast, classic HUS is caused by infection with verocytotoxin-producing bacteria. This toxin induces endothelial injury, apoptosis and inflammation. Endothelial injury results in increased shear-stress, fostering cleavage of VWF, but thrombosis eventually develops. One would assume that measurement of ADAMTS13 activity and/or detection of verocytotoxin could easily contribute to the differential diagnosis of TTP or HUS. We report on a case of a young patient with thrombotic microangiopathy and renal involvement with low ADAMTS13 concentrations which did not respond well to plasmapheresis therapy, but subsequent to the detection of verocytoxin producing E. coli with the serotype O157:H7, reacted well to antibiotic treatment. Sequencing of the ADAMTS13 gene revealed no mutations and no anti-ADAMTS13 antibodies could be detected. This case shows overlapping presentations as well as etiologies for both TTP and HUS, a finding also underscored by a recent animal model in which verocytoxin triggered development of TTP in ADAMTS13-deficient mice.

[Acute myopia and progressive acute renal failure in a 28-year old active horsewoman]. / Visusverlust und akutes Nierenversagen bei einer 28-jährigen aktiven Reiterin.

A 28-year old active sportswoman was admitted to hospital suffering from fever, menigeal irritation, acute myopia and progressive acute renal failure. Showing signs of polyserositis in combination with pulmonary granulomatous changes a collagenosis as well as an atypical pneumonia was excluded first. Due to the renal loss of function a renal biopsy was taken with the typical histological result of a hantavirus infection. This could be confirmed serologically in the following. With symptomatic treatment the patient had an uneventful complete recovery during the next four weeks.

Transdifferentiation of endothelial and renal tubular epithelial cells into myofibroblast-like cells under in vitro conditions: a morphological analysis.

Renal fibrosis is a hallmark of progressive kidney disease and is characterized by an accumulation of extracellular-matrix-synthesizing cells in the glomerulus and tubulointerstitium. This population of myofibroblast-like cells (MFLC) is heterogeneous. It has been experimentally shown, for example, that tubular epithelial cells could change their phenotype into MFLC under certain circumstances, a process called epithelial-mesenchymal transdifferentiation. However, MFLC may also originate from other sources. Therefore, we examined whether endothelial cells (EDC) are able to transdifferentiate into MFLC in vitro. We compared potential differences between syngeneic tubular epithelial cells (EPC) and EDC during transdifferentiation into MFLC using bovine and porcine EDC isolated from pulmonary arteries, and glomerular capillaries. Renal tubular EPC were prepared from bovine renal cortical tissue by collagenase digestion and isolation from homogeneous cell monolayers. Bovine renal tubular EPC stained positive for cytokeratin. Furthermore, tubular EPC selectively incorporated labeled bovine serum albumin, a typical property of differentiated renal tubular cells. EDC were characterized by the absence of epithelial markers (e.g. cytokeratin), but stained positive for vWF. The transdifferentiation of EDC into MFLC occurs sequentially in two steps: First, by a rapid reversible transformation in postconfluent or clonal cultures without the need of cytokine stimulation and second, by a prolonged secondary step in the presence of the transformation-accelerating cytokines and the absence of adherently growing EDC. Thus, EDC that are able to sprout can also irreversibly transdifferentiate into MFLC. On the other hand, prolonged incubation of EPC in the presence of cytokines such as transforming growth factor-beta1 and tumor necrosis factor-alpha leads only to a very small number of MFLC without the ability to further proliferate. Our in vitro data suggest that EDC can more easily transdifferentiate into MFLC than syngeneic renal tubular EPC.

Effect of L-methionine supplementation on plasma homocysteine and other free amino acids: a placebo-controlled double-blind cross-over study.

OBJECTIVE: The essential amino acid L-methionine is a potential compound in the prophylaxis of recurrent or relapsing urinary tract infection due to acidification of urine. As an intermediate of L-methionine metabolism, homocysteine is formed. The objective was to study the metabolism of L-methionine and homocysteine, and to assess whether there are differences between patients with chronic urinary tract infection and healthy control subjects. DESIGN: A randomized placebo-controlled double-blind intervention study with cross-over design. SETTING: Department of Nutritional Physiology, Institute of Nutrition in cooperation with the Department of Internal Medicine III, Friedrich Schiller University of Jena, Germany. SUBJECTS: Eight female patients with chronic urinary tract infection and 12 healthy women (controls). INTERVENTIONS: After a methionine-loading test, the volunteers received 500 mg L-methionine or a placebo three times daily for 4 weeks. MAIN OUTCOME MEASURES: Serum and urinary concentrations of methionine, homocysteine, cystathionine, cystine, serine, glycine and serum concentrations of vitamin B12, B6 and the state of folate. RESULTS: Homocysteine plasma concentrations increased from 9.4+/-2.7 micromol/l (patients) and 8.9+/-1.8 micromol/l (controls) in the placebo period to 11.2+/-4.1 micromol/l (P=0.031) and 11.0+/-2.3 micromol/l (P=0.000), respectively, during L-methionine supplementation. There were significant increases in serum methionine (53.6+/-22.0 micromol/l; P=0.003; n=20) and cystathionine (0.62+/-0.30 micromol/l; P=0.000; n=20) concentrations compared with the placebo period (33.0+/-12.0 and 0.30+/-0.10 micromol/l; n=20). Simultaneously, renal excretion of methionine and homocysteine was significantly higher during L-methionine intake. CONCLUSIONS: Despite an adequate vitamin status, the supplementation of 1500 mg of L-methionine daily significantly increases homocysteine plasma concentrations by an average of 2.0 micromol/l in patients and in control subjects. An optimal vitamin supplementation, especially with folate, might prevent such an increase.

[Thrombotic thrombocytopenic purpura. Reduced activity of von Willebrand factor cleaving protease]. / Thrombotisch-thrombozytopenische Purpura. Verminderte Aktivität der von-Willebrand-Faktor-spaltenden Protease.

Thrombotic thrombocytopenic purpura (TTP) is a rare thrombotic microangiopathy. Besides anemia and thrombocytopenia, neurological impairment is common in TTP. A 42-year-old woman was admitted to a department of obstetrics/gynecology because of severe vaginal bleeding due to thrombocytopenia. After platelet transfusion, the patient developed a reduced level of consciousness, confusion, headache, and fever. CT scan did not show pathological changes. Transcranial Doppler sonography revealed increased blood flow velocities of all basal cerebral arteries. Because encephalitis was suspected the patient was transferred to the neurological department. CSF and cerebral magnetic resonance imaging studies were normal. Finally, the detection of schistocytes in the peripheral blood smear and the strong elevation of LDH led to the diagnosis of TTP. After plasma exchange over 3 consecutive days the patient achieved complete remission. The diagnosis was confirmed by laboratory tests (activity of ADAMTS13 <5%, IgG antibodies against ADAMTS13). Platelet transfusion may adversely affect the outcome of patients with suspected TTP. Severely deficient activity of the von Willebrand factor cleaving protease (ADAMTS13) is specific for thrombotic thrombocytopenic purpura.

Interleukin 4 co-stimulates the PDGF-BB- and bFGF-mediated proliferation of mesangial cells and myofibroblasts.

BACKGROUND: Although many mediators involved in the pathogenesis of fibrosis are known, its precise mechanism is still unknown. In vitro experiments may contribute to the recognition of cellular changes which also take place during fibrosis. METHODS: Renal tubular epithelial cells (EPC), mesangial cells (MC) and glomerular endothelial cells (GEDC) as well as endothelial cells (EDC) and myofibroblasts (MF) from cattle were isolated to measure the proliferation and protein synthesis in the presence of individual and combined cytokines/growth factors in cell cultures. RESULTS: Cytokines stimulating or permitting the proliferation of myofibroblast-like cells (MFLC) (MC and MF), caused damage of endothelial cells (EDC, GEDC), whereas EPC were stable. The proliferation of MFLC was strongly stimulated by PDGF-BB and bFGF and elevated more than twofold in the presence of interleukin 4 (IL-4), but IL-4 alone had no effect. Furthermore, the proliferation of transdifferentiated endothelial cells (TEC), obtained by incubation of EDC with TNFalpha and bFGF, was stimulated with both PDGF-BB/IL-4 and bFGF/IL-4 in the same way and proved to be stable with respect to TNFalpha. CONCLUSION: Interleukin 4 co-stimulates the PDGF-BB- and bFGF-mediated proliferation of MC, MF, and TEC. TNFalpha does not inhibit the proliferation of extracellular matrix-synthesizing cells, but has an inhibitory or even toxic effect on EDC and GEDC. It may be concluded that cytokines released in inflamed renal tissue influence tubulointerstitial cells in different ways, resulting in progressive tissue damage and fibrosis in which the EDC would be the most sensitive cells. Thus, we speculate that microvascular injury in these areas leads to ischemia and malnutrition of tubular EPC and may be responsible for ongoing tubular damage and resulting renal interstitial fibrosis.

The effects of prolonged physical exercise on renal function, electrolyte balance and muscle cell breakdown.

BACKGROUND: Postexercise proteinuria, hematuria and changes in serum electrolyte balance as well as increased levels of plasma indicators for muscle leakage are believed to be transient and of benign character. METHODS: A group of 51 healthy athletes took part in a 100 km race over 14.25 hours. All of them had to reach the finish together. Urine and blood samples were collected before (a) and immediately after running (b) as well as 6 hours after the race (c). RESULTS: The serum concentrations of potassium (4.8 +/- 0.5 (a) vs. 4.0 +/- 0.3 (c) mmol/l), protein (73.1 +/- 5.2 (a) vs. 71.1 +/- 3.9 (c) g/l) and albumin (44.0 +/- 2.85 (a) vs. 42.9 +/- 2.8 (c) g/l) decreased significantly (p < 0.0001, p < 0.05, p < 0.05, respectively) but remained within physiological ranges. The serum sodium concentration decreased immediately after the race (136.9 +/- 4.5 (a) vs. 131.1 +/- 2.4 (b) micromol/l, p < 0.0001). The fractional sodium excretion decreased 6 hours, but not immediately after the race (0.78 +/- 0.59 (a) vs. 0.48 +/- 0.82 (c), p < 0.05). Myoglobin (31.8 +/- 6.9 (a), 291.5 +/- 197.2 (b) and 182.2 +/- 135.3 (c) microg/l, p < 0.0001) and creatine kinase (1.13 +/- 0.45 (a), 10.76 +/- 6.9 (b) and 9.46 +/- 15.5 (c) pmol/l, p < 0.0001) increased dramatically. Troponin I was also significantly increased at finish (0.0186 +/- 0.0121 (a) vs. 0.0213 +/- 0.0165 (b) ng/ml, p < 0.05) and positively correlated with myoglobin and creatine kinase, but remained far below the pathologic range. Serum creatinine and urea remained almost unchanged. Glucosuria and hematuria occurred 6 hours after the run in 9.1% and 6.8%, respectively. The erythrocytes examined by phase-contrast microscopy were not damaged in terms of dysmorphic cells. Glomerular-type proteinuria was found in 11.4% of the participants 6 hours after the race. CONCLUSIONS: We conclude that long lasting, mild exertion is harmless for renal function, electrolyte balance and skeletal muscle as well as myocardial metabolism in healthy persons.