Rosiglitazone reduces angiotensin II and advanced glycation end product-dependent sustained nuclear factor-kappaB activation in cultured human proximal tubular epithelial cells

Tubular damage is a major feature in the development of diabetic nephropathy. This study investigates the effects of the thiazolidindione rosiglitazone on angiotensin II and advanced glycation end product-induced tubular activation in human proximal tubular epithelial cells IN VITRO. Angiotensin II and advanced glycation end products, both induced a dose-dependent sustained activation of the redox-sensitive transcription factor, Nuclear Factor KAPPA B (NF-kappaB). Nuclear translocation of NF-kappaB was evident already after one hour and persistent for more than four days. Co-incubation of proximal tubular epithelial cells with rosiglitazone significantly reduced angiotensin II and advanced glycation end product-mediated generation of reactive oxygen species, angiotensin II-dependent advanced glycation end product formation, NF-kappaB activation, and NF-kappaB-dependent pro inflammatory gene expression. Most importantly, rosiglitazone effects on NFkappaB activation were maximal at later time points, indicating that rosiglitazone treatment confers long lasting renoprotective effects.

Continuous ambulatory peritoneal dialysis--developments during changing times

INTRODUCTION

Continuous ambulatory peritoneal dialysis (CAPD) treatment is subject to constant changes. Departing from this thesis, it should be analyzed in which respects CAPD treatment at the Heidelberg outpatient clinic has changed when considering demographic data, and CAPD-specific data including infection rates and clinical parameters.

MATERIALS AND METHODS

A retrospective study was carried out in the course of which a cohort of 67 CAPD patients treated before the year 2000 was compared with a cohort of 53 patients treated from the year 2000 on. Demographic data, CAPD-specific and clinical data at the commencement of treatment and data gathered during the observation period thereafter were recorded.

RESULTS

The patients of the more recent cohort were 5 years older. At the initiation of treatment, the volume of residual diuresis was higher in the patients treated from 2000 on than in those treated before. The blood pressure in patients belonging to the more recently treated group was also lower than the blood pressure of those treated before. The incidence of peritonitis and exit-site infections has decreased. On the other hand, the hemoglobin level has risen.

DISCUSSION

Compared to the past, many parameters have improved. Above all, the findings suggest that medical care and treatment have become better, probably as a result of the modified guidelines. The significant decrease in infections is probably also due to the use of the new dialysis fluids.

Effects of mycophenolic acid on human fibroblast proliferation, migration and adhesion in vitro and in vivo

Mycophenolic acid (MPA) is a potent inhibitor of the inosine monophosphate dehydrogenase and used as an immunosuppressive drug in transplantation. MPA inhibits proliferation of T- and B-lymphocytes by guanosine depletion. Since fibroblasts rely on the de novo synthesis of guanosine nucleotides, it is assumed that MPA interacts with fibroblasts causing an increased frequency of wound healing problems. We show a downregulation of the cytoskeletal proteins vinculin, actin and tubulin in fibroblasts exposed to pharmacological doses of MPA using microarray technology, real-time polymerase chain reaction (PCR) and Western blot. This reduction in RNA and protein content is accompanied by a substantial rearrangement of the cytoskeleton in MPA-treated fibroblasts as documented by immunofluorescence. The dysfunctional fibroblast growth was validated by scratch test documenting impaired migrational capacity. In contrast, cell adhesion was increased in MPA-treated fibroblasts. The results of the cultured human fibroblasts were applied to skin biopsies of renal transplant recipients. Skin biopsies of patients treated with MPA expressed less vinculin, actin and tubulin as compared to control biopsies that could explain potential wound healing problems posttransplantation. The perspective of MPA-induced cytoskeletal dysfunction may go beyond wound healing disturbances and may have beneficial effects on (renal) allografts with respect to scarring.

Renal toxicity mediated by glucose degradation products in a rat model of advanced renal failure

BACKGROUND

In peritoneal dialysis (PD) residual renal function contributes to improved patient survival and quality of life. Glucose degradation products (GDP) generated by heat sterilization of PD fluids do not only impair the peritoneal membrane, but also appear in the systemic circulation with the potential for organ toxicity. Here we show that in a rat model of advanced renal failure, GDP affect the structure and function of the remnant kidney.

MATERIALS AND METHODS

Sprague-Dawley rats were randomly assigned to a two stage subtotal nephrectomy (SNX) or sham operation and were left untreated for 3 weeks. The SNX + GDP group continuously received chemically defined GDP intravenously for 4 weeks; the SNX and the sham-operated rats remained without GDP. The complete follow-up for all groups was 7 weeks postoperatively. We analysed renal damage using urinary albumin excretion as well as a semiquantitative score for glomerulosclerosis and tubulointerstitial damage, as well as for immunohistochemical analyses.

RESULTS

The SNX + GDP rats developed significantly more albuminuria and showed a significantly higher score of glomerulosclerosis index (GSI) and tubulointerstitial damage index (TII) as compared to SNX or control rats. In the SNX + GDP group the expression of carboxymethyllysine and methylglyoxal was significantly higher in the tubulointerstitium and the glomeruli compared to the SNX rats. Caspase 3 staining and TUNEL assay were more pronounced in the tubulointerstitium and the glomeruli of the SNX + GDP group. In SNX + GDP animals, the expression of the slit diaphragm protein nephrin, was significantly lower compared to SNX or control animals.

CONCLUSION

In summary, our data suggests that GDP can significantly advance chronic kidney disease and argues that PD solutions containing high GDP might deteriorate residual renal function in PD.

Thymoglobulin and ischemia reperfusion injury in kidney and liver transplantation

Since the beginning of organ transplantation, graft preservation has been one of the most important concerns. Ischemia reperfusion injury (IRI), which plays an important role in the quality and function of the graft, is a major cause for increased length of hospitalization and decreased long term graft survival. Among numerous attempts which have been made to minimize graft damage associated with IRI, the use of Thymoglobulin (TG) seems to offer potential benefits. TG is a polyclonal antibody which blocks multiple antigens related to IRI, in addition to its better known T cell depleting effects. This review will focus on the use of TG in preventing IRI in kidney transplantation (KTx) and liver transplantation (LTx). Different studies in experimental and clinical transplantation have shown that TG protects renal and liver grafts from IRI. Improvement in early graft function and decreased delayed graft function (DGF) rates are some of the clinical benefits of TG. Additionally, it is used in patients with hepatorenal syndrome to support the recovery of kidney function after LTx, by allowing reduced exposure to nephrotoxic calcineurin inhibitors as well as improving liver graft function by minimizing IRI. TG can reduce acute rejection rates in kidney and liver transplant recipients, decrease the length of hospital stay, and hence reduce transplantation costs. TG can play an important role in expanding the donor pool in both KTx and LTx by improving long-term graft and patient survival rates which increases the possibility of using marginal donors. Although controversial, the development of post-transplant lymphoproliferative disorder is a potential side effect of TG. No single optimal immunosuppressive regimen has given consistent results in decreasing the graft damage following IRI; however, TG usage in KTx and LTx appears to have some benefits in reducing IRI.

[Emerging zoonoses: Hantavirus infections]

Die weltweite Verbreitung und die jährlich steigende Zahl der Infektion mit Hantaviren lässt die Bedeutung der Hantaviren unter den „emerging viruses“ ansteigen. Die Ansteckung verläuft über das Einatmen von Staub oder Aerosolen, die mit Ausscheidungen infizierter Nagetiere kontaminiert sind. Krankheitsbild und Schwere des Verlaufs hängen vom Virustyp ab, dessen geographisch begrenztes Auftreten vom Vorkommen des virustypspezifischen Nagerreservoirs bestimmt wird. Die Infektion mit in Asien und Europa beheimateten Stämmen löst das hämorrhagische Fieber mit renalem Syndrom (HFRS) aus. Die in Deutschland vorherrschende Virusspezies Puumala löst eine mildere Verlaufsform des HFRS, die Nephropathia epidemica (NE), aus. Infektionen mit Hantavirus-Stämmen des amerikanischen Kontinents hingegen führen zu einem Krankheitsbild mit vorwiegend pulmonaler Symptomatik (hantavirales pulmonales Syndrom, HPS). Da für keinen der humanpathogenen Vertreter eine spezifische antivirale Therapie oder ein zugelassener Impfstoff zur Verfügung steht, bleibt zur Eindämmung und Vermeidung der Infektion nur die Kontrolle der Nagerpopulationen und Präventionsmaßnahmen des expositionsgefährdeten Personenkreises.

Anti-chromatin and anti-C1q antibodies in systemic lupus erythematosus compared to other systemic autoimmune diseases

OBJECTIVE

To evaluate the prevalence, sensitivity, and specificity of anti-chromatin and anti-C1q antibodies in systemic lupus erythematosus (SLE) and lupus nephritis compared to small vessel vasculitis and other connective tissue diseases. To provide long-term follow-up data for anti-chromatin antibodies in lupus nephritis.

METHODS

We determined the significance of anti-nuclear antibodies (ANA), anti- double-stranded DNA (anti-dsDNA), anti-chromatin, and anti-C1q antibodies, as well as complement factors C3 and C4, in relation to disease activity in SLE patients with (n = 47; long-term follow-up data for 33 patients) and without (n = 31) biopsy-confirmed lupus nephritis, microscopic polyangiitis (n = 37), Wegener's granulomatosis (n = 66), primary Sjögren's syndrome (n = 17), limited scleroderma (CREST syndrome) (n = 6), and progressive systemic scleroderma (PSS) (n = 11).

RESULTS

Anti-chromatin antibodies were more specific and sensitive than anti-C1q antibodies in distinguishing SLE patients from those with other systemic autoimmune diseases [anti-chromatin: sensitivity 64.1%, specificity 99.2%, odds ratio (OR) 219.6; anti-C1q: sensitivity 50%, specificity 72.6%, OR 2.65]. Anti-C1q antibodies were present in 75% of patients with Sjögren's syndrome and 35.1% of patients with microscopic polyangiitis. Anti-chromatin antibodies could identify SLE in patients with positive ANA but negative anti-dsDNA antibodies. Persisting anti-chromatin antibodies indicated SLE disease activity, even if anti-dsDNA antibodies had become negative. In long-term follow-up, those SLE patients with negative anti-dsDNA antibodies but persisting ANA and anti-chromatin antibodies relapsed if immunosuppression had been tapered. Anti-chromatin antibodies correlated with the SLE disease activity index (SLEDAI) as a marker of disease activity.

CONCLUSIONS

The measurement of anti-chromatin, but not anti-C1q, antibodies in patients with systemic autoimmune diseases increases diagnostic sensitivity and specificity for SLE and assists in treatment decisions in anti-dsDNA-negative patients.

Long-term treatment of central Cushing's syndrome with rosiglitazone

CONTEXT

Central Cushing's syndrome is not always curable by surgery or radiation of the pituitary. Medical treatment is often not possible or effective. Some studies revealed beneficial effects of the PPARgamma (Peroxisome-Proliferator-Activator- Receptor-gamma)-agonist rosiglitazone (RG) in in vitro studies, animal models and short term clinical studies.

OBJECTIVE

of this study was to observe the long-term effects of RG-treatment on cortisol- and ACTH -secretion, clinical outcomes and morphological changes of the pituitary in patients with persistent ACTH-overproduction despite previous operation and radiation.

DESIGN, SETTING AND PATIENTS

14 patients with persistent central ACTH -production were included and monitored over a period up to 12 months. RG was administered daily and increased to a maximum dosage of 24 mg daily, according to the response of ACTH and cortisol secretion. ACTH and cortisol were measured at least every 4 weeks during RG treatment.

RESULTS

Patients were treated between 4 and 12 months with RG (mean 6.8 months). Compared to baseline, ACTH- and cortisol levels dropped significantly (p<0.01) after 12, 16, 20, 24 and 28 weeks but thereafter rose again during the study period, despite continuous RG- treatment and dose increase up to the maximum dosage. This was paralleled by reocurrence of clinical symptoms. MRI-scans were performed in 6 patients because of persisting visible adenoma, but showed no morphological changes.

CONCLUSION

RG seems not to be a long-term treatment option for patients with persistent central ACTH-evcess. Though, in order to reduce perioperative complications, short term treatment of patients could be an alternative.

Efficacy and Safety of Enteric-Coated Mycophenolate Sodium in De Novo Renal Transplant Recipients: Pooled Data From Three 12-Month Multicenter, Open-Label, Prospective Studies

BACKGROUND

The myfortic Prospective Multicenter Study (myPROMS) utilizes a core protocol in which renal transplant patients receive enteric-coated mycophenolate sodium (EC-MPS) and cyclosporine microemulsion. Substudies investigate specific aspects of the immunosuppressive regimen.

METHODS

A pooled analysis of three 12-month myPROMS substudies in de novo renal transplant patients was undertaken. Patients in the US01 and DE01 substudies were randomized to higher or lower cyclosporine C(2) target ranges; patients in FR01 were randomized to early or delayed introduction of cyclosporine. All patients received steroids and interleukin-2 receptor antagonist induction.

RESULTS

In total, 456 patients were included in the pooled analysis. Treatment failure (biopsy-proven acute rejection, graft loss, or death) occurred in 118 patients (25.9%) by month 12, with biopsy-proven acute rejection reported in 101 patients (22.1%). Fourteen patients (3.1%) lost their graft, and six patients died (1.3%). Median calculated creatinine clearance was 62.9 mL/min at month 12 (median serum creatinine, 138 +/- 51 mumol/L). Gastrointestinal (GI) adverse events were reported in 354 patients (77.6%); these were mild or moderate in 323 patients. Within 12 months, 16.2% of patients required EC-MPS dose changes for GI adverse events. GI disorders led to EC-MPS discontinuation in only 10 patients (2.2%). Over the 12-month study, mean EC-MPS dose was 1352 +/- 230 mg/d (94% of recommended dose).

CONCLUSION

Cyclosporine, EC-MPS, and steroids with interleukin-2 antagonist induction offers effective and well-tolerated immunosuppression following renal transplantation. Graft survival was excellent and renal function was stable. High EC-MPS dosing was sustained throughout (>90% recommended dose) and dose modifications due to EC-MPS-related adverse events or infections were infrequent.

Cardiac biomarkers and survival in haemodialysis patients

BACKGROUND

In dialysis patients, cardiac troponin T (cTNT) is often elevated despite the absence of acute myocardial ischaemia, and amino-terminal pro-B-natriuretic peptide (NT-proBNP) is markedly higher compared to non-haemodialysis patients. In a longitudinal observation, we evaluated the association of cTNT and NT-proBNP on cardiovascular morbidity and mortality in haemodialysis patients with and without fluid overload.

MATERIALS AND METHODS

Plasma cTNT levels of 134 haemodialysis patients were measured before and after a dialysis session by 3rd generation electro-chemoluminiscence immunoassay. NT-proBNP was determined using a polyclonal antibody recognizing the N-terminal fragment of BNP (Elecsys autoanalyzer 2010, Roche Diagnostics, Mannheim, Germany). Volume status was determined by a clinical score system. Cardiovascular morbidity and mortality were assessed over a follow-up period of 36 months.

RESULTS

Plasma cTNT > 0.03 ng mL(-1) was found in 39.6% of all patients. Patients with hypervolaemia had significantly higher cTNT levels compared to euvolaemic patients (median 0.054 ng mL(-1), interquartile range 0.019-0.153 vs. 0.005 ng mL(-1), < 0.001-0.034; P < 0.001). All haemodialysis patients had excessively high levels of NT-proBNP (median 4524; interquartile range 2000-10 250 pg mL(-1)), and NT-proBNP was significantly higher in hypervolaemic haemodialysis patients (11 988, 5307-19 242) compared to euvolaemic haemodialysis patients (3247, 1619-5574); P < 0.001. Receiver operator curves showed a threshold of cTNT > 0.026 ng mL(-1) and NT-proBNP > 5300 pg mL(-1) as predictors of hypervolaemia. Asymptomatic chronic haemodialysis patients with cTNT > 0.026 ng mL(-1) and NT-proBNP > 5300 pg mL(-1) were more likely to die due to cardiac events in the follow-up period. Multivariate analysis documented that elevated cTNT and NT-proBNP levels were highly predictive for cardiovascular events.

CONCLUSIONS

Plasma levels of cTNT are elevated in approximately 40% and NT-proBNP levels in 100% of asymptomatic chronic haemodialysis patients. Both parameters depend on volume status. Increased NT-proBNP and cTNT are strongly associated with adverse outcome in end-stage renal disease patients undergoing haemodialysis, and are a useful tool for risk stratification in chronic haemodialysis patients.

Wound complications following kidney and liver transplantation

Advances in surgical techniques and immunosuppression (IS) have led to an appreciable reduction in postoperative complications following transplantation. However, wound complications as probably the most common type of post-transplantation surgical complication can still limit these improved outcomes and result in prolonged hospitalization, hospital readmission, and reoperation, consequently increasing overall transplant cost. Our aim was to review the literature to delineate the evidence-based risk factors for wound complications following kidney and liver transplantation (KTx, LTx), and to present the preventive and therapeutic modalities for this bothersome morbidity. Generally, wound complications are categorized as superficial and deep wound dehiscences, perigraft fluid collections and seroma, superficial and deep wound infections, cellulitis, lymphocele and wound drainage. The results of several studies showed that the most important risk factors for wound complications are IS and obesity. Additionally, there are surgical and/or technical factors, including type of incision, reoperation, and surgeon's expertise, as well as comorbidities such as advanced age, diabetes mellitus, malnutrition, and uremia. Preventive management of wound complications necessitates defining their etiological factors so that their detrimental effects on healing processes can be addressed and reduced. IS modalities and agents, especially sirolimus (SRL), and steroids (ST) should be adjusted according to the patient's co-existing risk factors. SRL should be administered three months after transplantation and ST should be tapered as soon as possible. A body mass index (BMI) lower than 30 kg/m2 is advisable for inclusion in a transplantation program, but higher BMIs do not exclude recipients. Surgical risk factors can be prevented by applying precise surgical techniques. Therapeutic modalities must focus on the most efficient and cost-effective medications and/or interventions to facilitate and improve wound healing.

The role and value of sirolimus administration in kidney and liver transplantation

Enormous advancements in visceral transplantation have led to significant improvements in the quality of life of patients. However, despite these developments, the average graft half-life after transplantation has remained almost unchanged and chronic rejection is still considered a major problem. In this regard, more concerns have shifted to factors influencing long-term graft survival, patient survival, and quality of life. To achieve this goal, detrimental effects of immunosuppressive (IS) agents, which have deleterious influence on the quality of life and/or patient survival, should be reduced. In the course of recent years, the transplant community has worked on reducing these side effects by developing new ISs, employing new combination regimens, or finding and adjusting optimal dosages and blood level concentrations. Among the IS agents, the antifungal, antitumoral and IS activity of mammalian target of rapamycin (mTOR) inhibitors without nephrotoxicity, have received special attention regarding this new class of IS. Sirolimus (SRL), as the first member of mTOR inhibitors, has been utilized in many clinical trials with respect to its benefit-risk assessment. In our review, the clinical evolution of SRL, as well as the evidence-based clinical benefits of SRL in kidney and liver transplantation (KTx, LTx), are summarized. Various studies of SRL in KTx and LTx have shown that combination therapy with SRL will enrich the variety of IS modalities. It also can be regarded as a safe base therapy to which other necessary drugs can be added. In addition to the enhanced acute rejection prophylaxis, and in contrast to the calcineurin inhibitors (CNI) and steroids, this drug solely does not have common side effects such as nephrotoxicity, neurotoxicity, diabetes mellitus and hypertension. Moreover, this agent might diminish vasculopathic processes that mediate chronic allograft nephropathy (CAN). Therefore, by reducing the likelihood of CAN it can decrease the rate of long-term organ failure. One possibly desirable characteristic of SRL is its antiproliferative effect, which could provoke antitumoral or antiatherogenic activity following transplantation. Despite all promising impacts of SRL in organ transplantation, there are some concerns regarding the adverse effects of this drug, for instance dyslipidemia, pneumonitis and wound healing problems. However, the majority of these side effects can be reduced or ceased by careful dose adjustments and correct timing of use. In conclusion, after a decade of both in vivo and in vitro studies on SRL, it can be advocated that SRL is a promising, potent and effective IS agent as it reduces the rate of acute rejection episodes in de novo transplants. It could improve the quality of life, graft and patient survival rate, and achieve excellent outcomes with few adverse effects when wisely used in combination with other immunosuppressants.

Reduced-exposure cyclosporine is safe and efficacious in de novo renal transplant recipients treated with enteric-coated mycophenolic acid and basiliximab

BACKGROUND

The lower limit of exposure to calcineurin inhibitors has not yet been established in de novo renal transplant patients receiving mycophenolic acid therapy with basiliximab.

METHODS

A 12-month, multicenter, randomized, open-label trial was carried out in which de novo renal transplant patients received enteric-coated mycophenolate sodium, cyclosporine microemulsion, steroids and basiliximab. Patients were randomized to receive standard-exposure (n = 45) or reduced-exposure (n = 44) cyclosporine, based on differing C2 target ranges, after the first month post-transplant.

RESULTS

Cyclosporine exposure gradually increased over the first month and was lower than previously recommended. Mean calculated creatinine clearance (primary end-point) was similar in the standard-exposure and reduced-exposure groups at month 6 (55.3+/-3.2 ml/min and 61.5+/-3.7 ml/min respectively, n.s.). There were 4 deaths but no death-censored graft losses, resulting in 95.5% patient and graft survival at one year in both groups. At 6 and 12 months, the incidence of biopsy-proven acute rejection was 17.8% and 17.8% in the standard-exposure group, and 13.6% and 15.9% in the reduced-exposure group. Adverse events were similar between treatment groups. Exploratory analyses could not identify a lower limit for the optimal CsA exposure range, but results suggested that high exposure at one year was associated with deteriorating renal function.

CONCLUSIONS

These results indicate that enteric-coated mycophenolate sodium with reduced-exposure cyclosporine, steroids and basiliximab induction has an excellent therapeutic effect and is safe in de novo kidney transplant recipients. Lower C2 targets than previously recommended, particularly early post-transplant, do not appear to be associated with compromised efficacy.

Four cases of sirolimus-associated interstitial pneumonitis: identification of risk factors

Sirolimus-associated interstitial pneumonitis is a severe side effect of sirolimus therapy; fatal outcomes have been described. We report 4 patients with sirolimus-associated interstitial pneumonitis and review the literature for risk factors for the development of disease. Until June 2005, 48 patients received either de novo sirolimus treatment (n = 7) or were switched from a calcineurin inhibitor-containing regimen to a sirolimus-based protocol for various indications (n = 41). Compared with the 44 patients on sirolimus therapy with no evidence of a disorder, the 4 patients (8.3%) who developed suspected sirolimus-associated interstitial pneumonitis showed no difference in gender, immunosuppressive therapy, days posttransplantation, comorbidity, or preexistent lung disease. Several points, however, are of interest. None of the de novo-treated patients except 4 patients (9.8%) with late administration of sirolimus developed interstitial pneumonitis. The 4 patients with interstitial pneumonitis tended to be older (58.7 +/- 5.5 vs 46.9 +/- 1.7 years) and received higher sirolimus doses (3.5 +/- 0.5 vs 1.4 +/- 0.2 mg/d) with greater trough levels (15.4 +/- 2.9 vs 8.0 +/- 1.2 micro g/L) at the onset of symptoms. Most notably, all patients with interstitial pneumonitis had a loading dose at the start of therapy, and an increase in sirolimus dose (or trough level) within 3 weeks prior to the onset of symptoms. Additional potential risk factors identified from the literature include allograft dysfunction, hypervolemia, and male gender. With careful monitoring (or even exclusion from therapy) of patients at risk for the development of disease, we have had no case of sirolimus-associated interstitial pneumonitis since September 2004.

Proton spin structure in the resonance region

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV<W<1.910 GeV) at an average four momentum transfer of Q2=1.3 GeV2. Using the Jefferson Lab polarized electron beam, a spectrometer, and a polarized solid target, we measured the asymmetries A|| and A(perpendicular) to high precision, and extracted the asymmetries A1 and A2, and the spin structure functions g1 and g2. We found a notably nonzero A(perpendicular), significant contributions from higher-twist effects, and only weak support for polarized quark-hadron duality.

Liquefaction necrosis of mitral annulus calcification in a patient with chronic renal failure: an unrecognized diagnosis

Mitral annulus calcification is one of the most common cardiac calcifications. In patients with end-stage renal disease undergoing echocardiography, it can be detected in more than 40%. A specific form of mitral annulus calcification is liquefaction necrosis. It is often not adequately recognized by echocardiographers or clinicians and can be mistaken for cardiac tumor or infective vegetation. Here we report a case of liquefaction necrosis of mitral annulus calcification, mimicking an infective vegetation of the mitral valve apparatus in a patient with chronic renal failure.

[Renal replacement therapy in the intensive care unit]

Acute renal failure in critically ill patients in the intensive care unit is associated with high morbidity and mortality which is independent of the underlying etiology. Despite improvements in intensive care medicine and renal replacement therapy, patients with acute renal failure have much higher morbidity and mortality rates than patients without acute renal failure in the intensive care unit. In this overview, we summarize the literature on the incidence and mortality of patients with acute renal failure in the intensive care unit. Furthermore, we discuss timing of the initiation of renal replacement therapy, patient outcome with different renal replacement therapies and the adequate dialysis dose to be delivered.

Desensitization strategies enabling successful renal transplantation in highly sensitized patients

Currently, the number of highly sensitized patients awaiting a renal transplant is increasing on the waiting lists of different organ exchange organizations. Due to the presence of antibodies against a broad variety of human leukocyte antigen (HLA) specificities, highly sensitized patients have a markedly reduced chance of receiving a crossmatch-negative organ. It has long been recognized that hyperacute rejection is associated with the presence of donor-specific anti-HLA antibodies at the time of transplantation. Meanwhile treatment protocols have been developed to achieve successful transplantation across antibody barriers. Therefore, the presence of donor-specific anti-HLA antibodies and a positive serological crossmatch are no longer considered as an absolute contraindication to renal transplantation. Mainly, two desensitization protocols have been established in order to overcome a positive crossmatch or to enhance the chance of highly sensitized patients to receive a crossmatch-negative organ: high-dose intravenous immunoglobulin (IVIg) or low-dose IVIg in combination with plasmapheresis. Herein, we summarize the characteristics of these two treatment regimes along with other alternative approaches that are currently used for the management of kidney graft recipients with broad alloantibody reactivity against potential kidney donors.

Immunosuppressive standards in simultaneous kidney?pancreas transplantation

Simultaneous pancreas-kidney transplantation is an established procedure for patients with type I diabetes and end-stage renal disease. Continuous advances in the operation techniques with consequent reduction of perioperative morbidity and mortality and the introduction of modern immunosuppressive agents improved not only patients but also graft survival and significantly decreased rejection episodes of both kidney and pancreas grafts. Availability of a variety of new immunosuppressants in the clinical routine and increasing experience of the transplant specialists allowed further developments of therapeutic schemes with application of induction and maintenance immunosuppressive protocols. In this article, we summarize the current status of immunosuppressive regimens in simultaneous pancreas and kidney transplantation.

Color Doppler indices of renal allografts depend on vascular stiffness of the transplant recipients

A resistance index (RI) of 0.8 or higher was shown to be a strong predictor of kidney allograft and patient survival. Uncertainties persist since the intrarenal RI is closely associated with the vascular stiffness of the allograft recipient. To clarify the diagnostic value of RI further, we analyzed parameters of vascular stiffness of the recipient and intrarenal RI of the renal allograft. In a prospective study laboratory and clinical parameters, pulse wave velocity (PWV), intima media thickness (IMT) and RI were obtained in 76 kidney allograft patients. We found that the RI values significantly correlated with the PWV (p < 0.05) and the recipients age (p < 0.01) but not with the donor age and renal function. Using multiple regression analysis recipient age, PWV, pulse pressure (PP) and IMT were identified as independent factors influencing RI values. For a more correct interpretation of the RI values in renal allografts parameters of vascular stiffness such as IMT, PP or PWV should be included.

Real-time contrast-enhanced sonography of renal transplant recipients predicts chronic allograft nephropathy

Real-time contrast-enhanced sonography (RT-CES) can assess microvascular tissue perfusion using gas-filled microbubbles. The study was performed to evaluate the feasibility of RT-CES in detecting chronic allograft nephropathy (CAN) in comparison to color Doppler ultrasonography (CDUS). A total of 26 consecutive renal transplant recipients were prospectively studied using RT-CES and conventional CDUS. Transplant tissue perfusion imaging was performed by low-power imaging during i.v. administration of the sonocontrast Optison. Renal tissue perfusion was assessed quantitatively using flash replenishment kinetics of microbubbles to estimate renal blood flow A *beta (A = peak signal intensity, beta= slope of signal intensity rise). In contrast to conventional CDUS resistance and pulsatility indices, renal blood flow estimated by CES was highly significant related to S-creatinine (r =-0.62, p = 0.0004). Determination of renal blood flow by CES reached a higher sensitivity (91% vs. 82%, p < 0.05), specificity (82% vs. 64%, p < 0.05) and accuracy (85% vs. 73%, p < 0.05) for the diagnosis of CAN as compared to conventional CDUS resistance indices. Perfusion parameters derived from RT-CES significantly improve the early detection of CAN compared to conventional CDUS. RT-CES using low-power real-time perfusion imaging is a feasible method to evaluate microvascular perfusion in renal allograft recipients.

The first 5 years of the family clinic for HIV at Tygerberg Hospital: family demographics, survival of children and early impact of antiretroviral therapy

BACKGROUND

Family clinics address the problems of HIV-infected children and their families. The aims were to document demographics of the children and caregivers attending the Family Clinic for HIV at Tygerberg Academic Hospital (TAH) and to investigate factors affecting disease progression in children.

METHODS

A retrospective folder review of children and parents attending the Family Clinic at TAH between January 1997 and December 2001, a period noted for its lack of antiretroviral treatment.

RESULTS

Of 432 children seen for testing, 274 children, median age 16.9 months, were HIV-infected. During follow-up, 46 children died (median age 23 months) and 113 were lost to follow-up. The majority of children were malnourished. Those <2 years of age had lower weight for age Z-scores (WAZ) than older children (p<0.001). At presentation, 47 per cent were in clinical stage B and two-thirds had moderate or severe CD4+ T cell depletion. Seventeen children had received highly active antiretroviral therapy (HAART), 12 dual and 31 monotherapy. HAART was associated with improved survival compared to dual or monotherapy. Risk of death was reduced from eleven-fold for a WAZ <-4 to four-fold between -2 and -3. There was no association with immunological and clinical classification at entry and risk of mortality. Only 18 per cent of parents were evaluated in the clinic. Non-parental care was documented for 25 per cent of families.

CONCLUSIONS

A low WAZ is associated with poor survival in children. Nutritional status should receive more attention in HIV disease classification in children. Parent utilization of the clinic was inadequate. Even in the absence of HAART, extended survival in children is possible.

Integriertes Skills-Lab-Konzept für die studentische Ausbildung in der Inneren Medizin

BACKGROUND AND OBJECTIVE

An amendment to the German medical curriculum in April 2002 will place basic practical skills at the centre of medical training. We report here on the implementation and evaluation of an obligatory, tutor-guided, and integrated skills laboratory concept in the field of internal medicine.

METHODS

To test the effectiveness of a skills laboratory training on OSCE performance a pilot study was carried out. The experimental group, of 77 students, participated in seven sessions of communication training, skills laboratory training, and bedside teaching, each lasting one and a half hours. The control group of 66 students had as many sessions but was only offered bedside-teaching. The evaluation of acceptance of skills' training as well as the related increase in individual competence is on-going (summer term 2004: n = 176 students).

RESULTS

The integrated skills laboratory concept was rated at 3.5 (SD = 1.2) on a 5-point scale and was acknowledged as practice-oriented (M = 4.2; SD = 1.0) and relevant for doctors' everyday lives (M = 3.6; SD = 1.1). Increased levels of competence according to individual self-evaluations proved to be highly significant (p<.001), and results of the pilot study showed that the experimental group had a significantly better OSCE performance than the control group (p<.001).

CONCLUSION

This pilot study shows that curriculum changes promoting basic clinical skills are effective and lead to an improved practical education of tomorrow's physicians. The integrated skills laboratory concept is well accepted and leads to a relevant increase in competence in the practice of internal medical. The presented skills laboratory concept in internal medicine is proving to be a viable and efficient learning tool.

Angular distributions for (3,4)(Lambda)H bound states in the (3,4)He(e,e(')K+) reaction

The (3,4)(Lambda)H and (4)(Lambda)H hypernuclear bound states have been observed for the first time in kaon electroproduction on (3,4)He targets. The production cross sections have been determined at Q(2)=0.35 GeV2 and W=1.91 GeV. For either hypernucleus the nuclear form factor is determined by comparing the angular distribution of the (3,4)He(e,e(')K+)(3,4)(Lambda)H processes to the elementary cross section 1H(e,e K+)Lambda on the free proton, measured during the same experiment.

Correlated strength in the nuclear spectral function

We have carried out an (e,e'p) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment locates by direct measurement the correlated strength predicted by theory.

Blood pressure profile and treatment quality in liver allograft recipients—benefit of tacrolimus versus cyclosporine

Organ transplant recipients display a high cardiovascular mortality rate. The type of immunosuppression has a major impact on cardiovascular risk factors (e.g., hypertension [HTN]). We assessed 24-hour blood pressure (BP) and metabolic profiles in a cohort of 106 long-term liver allograft recipients treated with either tacrolimus (Tac) or cyclosporine (CyA). The median age of patients was 50.8 years (range, 11 to 77) and the median time of follow-up was 65.4 months (ranges 12 to 168). Immunosuppression included low-dose steroids and either Tac (n = 46) or CyA (n = 60). Twenty-four-hour BP measurements revealed a significant difference in systolic BP (127.1 mmHg [94 to 163] Tac versus 132.7 mmHg [103 to 177] CyA; P <.03), and in mean arterial and diastolic blood pressures. In addition, the relative number of normotensive patients was significantly higher among Tac-treated patients (69.6% versus 34.8%). It is of note that the true incidence of HTN was higher after the number of patients with a pathological 24-h BP measurement was added to the initial number of patients already known to have HTN. No less than 76.4% of all long-term liver transplanted patients showed HTN. The results were unrelated to cumulative steroid dosage, frequency of antirejection therapy or underlying primary liver disease. In summary, immunosuppression-induced HTN is more common in CyA-treated than Tac-based regimens. Moreover, we found a substantial lack of detection of HTN in long-term liver transplant patients who received an insufficient quality of antihypertensive treatment. These findings have implications for the early diagnosis and treatment of HTN in liver transplant recipients.

Bovine aortic endothelial cells are susceptible to hantavirus infection; a new aspect in hantavirus ecology

Hantaviruses are enveloped RNA viruses that belong to the family Bunyaviridae. They are the causative agents of hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Hantaviruses show a worldwide distribution with specific rodent species as natural hosts. It is known that rodents can transmit the virus via feces, urine, saliva, or bites to humans. Additionally, antibodies against different hantaviruses were also found in domestic animals, For example, Danes et al. documented hantavirus-specific IgG titers in 2% of examined cattle [Ceskoslov. Epidemiol. Mikrobiol. Imunol. 41 (1992) 15]. In order to clarify the possibility of a nonrodent and nonhuman hantavirus infection, the susceptibility of bovine aortic endothelial cells (BAEC) to Hantavirus serotype Puumala infection was investigated. The hantaviral nucleocapsid protein was detected in 95% of infected BAEC at the fourth cell culture passage 12 weeks after initial infection by immunofluorescence assay (IFA). The presence of Puumala virus (PUU) nucleocapsid protein and the viral glycoproteins G1 and G2 in infected cells were additionally confirmed by Western blot analysis. The viral RNA genome was identified in infected BAEC cultures and in cell-free culture medium at the fourth passage by reverse transcription polymerase chain reaction (RT-PCR), verified by cDNA nucleotide sequence analysis, showing a 98-100% homology to the input virus. The infected BAEC cultures were shown to express alpha(V)beta(3)-integrin surface receptors that are known to mediate virus entry in human cells and revealed no major cytopathic effects (CPEs) as assayed by immunofluorescence staining of the cytoskeletal components actin and microtubules. In the present study, we documented for the first time that a nonrodent and nonhuman aortic endothelial cell culture of bovine origin (BAEC) can be efficiently infected with a hantavirus. This finding is of particular importance because it adds new aspects to questions dealing with host species barrier, viral reservoir, virus transmission, and ecology of hantaviruses.

Review of the antiproliferative properties of mycophenolate mofetil in non-immune cells

Mycophenolate mofetil (MMF), the prodrug ofmycophenolic acid (MPA), is a selective, non-competitive and reversible inhibitor of inosine monophosphate dehydrogenase (IMPDH) and of the type II isoform in particular. IMPDH is the rate-limiting enzyme in the de novo biosynthesis of guanosine nucleotides. MMF strongly inhibits both T- and B lymphocyte proliferation and has been used in the prevention of acute and chronic allograft rejection since the mid 1990s. Recent evidence, however, suggests that MMF is also capable of inhibiting the proliferation of non-immune cells. In various cell lines, i.e. smooth muscle cells, renal tubular cells and mesangial cells, MPA reduced or even abrogated proliferation in response to proliferative stimuli. Furthermore, data from our own laboratory demonstrate a dose-dependent inhibition of dermal fibroblast proliferation by MPA. In animal studies, MMF ameliorated renal lesions in immune-mediated disease, i.e. in the anti-thy 1.1 model and experimental lupus nephritis, but was also effective in non-immune-mediated renal damage in the rat remnant-kidney model. These observations prompted several investigators to study the effects of MMF in proliferating (renal) disease of non-immune origin in humans. MMF significantly reduced proteinuria in minimal-change disease and focal segmental glomerulosclerosis. In addition, MMF showed beneficial effects in the treatment of chronic allograft nephropathy and calcineurin inhibitor toxicity through reduction of immune- and non-immune-mediated renal damage. MMF is well tolerated and has proven to be a relatively safe drug causing only minor bone marrow suppression. Taken together, there is a growing body of evidence pointing to therapeutic applications of MMF other than immunosuppression, in particular the prevention of fibrosis.

Bovine aortic endothelial cells are susceptible to Hantaan virus infection

Hantavirus serotype Hantaan (HTN) is one of the causative agents of hemorrhagic fever with renal syndrome (HFRS, lethality up to 10%). The natural host of HTN is Apodemus agrarius. Recent studies have shown that domestic animals like cattle are sporadically seropositive for hantaviruses. In the present study, the susceptibility of bovine aortic endothelial cells (BAEC) expressing alpha(V)beta(3)-integrin to a HTN infection was investigated. Viral nucleocapsid protein and genomic RNA segments were detected in infected BAEC by indirect immunofluorescence assay, Western blot analysis, and reverse transcription-polymerase chain reaction (RT-PCR), respectively. The results of this study strongly support our previous observation on Puumala virus (PUU) that has been propagated efficiently in BAEC. These findings open a new window to contemplate the ecology of hantavirus infection and transmission route from animal to man.

Measurement of the electric form factor of the neutron at Q2=0.5 and 1.0 GeV2/c2

The electric form factor of the neutron was determined from measurements of the d-->(e-->,e'n)p reaction for quasielastic kinematics. Polarized electrons were scattered off a polarized deuterated ammonia (15ND3) target in which the deuteron polarization was perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle detector. We find G(n)(E)=0.0526+/-0.0033(stat)+/-0.0026(sys) and 0.0454+/-0.0054+/-0.0037 at Q(2)=0.5 and 1.0 (GeV/c)(2), respectively.

Risk of mortality in patients with end-stage renal disease: the role of malnutrition and possible therapeutic implications

The mortality rate of dialysis patients is still considerably high. Beside the traditional risk factors, specific uremia-related risk factors are identified. Among them, hypoalbuminemia and malnutrition have a strong association to mortality in chronic dialysis patients. Various studies document a strong relation between reduced calorie and protein uptake and mortality in uremic patients. Several factors responsible for malnutrition in dialysis patients have been identified. These factors may be dialysis-associated, due to intercurrent illnesses or are associated with uremic complications (e.g. hyperparathyroidism, anemia, acidosis, etc.). Malnutrition is treatable and can be avoided by several means. Beside the increase in the dose of dialysis and adequate protein and calorie intake, intradialytic nutrition is an additional choice. The combination with specific drugs (e.g. growth hormone) may potentiate the success of the modified treatment modalities, particularly in patients who need nutritional support during an intercurrent illness. Further studies are required to measure the impact of for example growth hormone supplementation on mortality rate and quality of life in malnourished patients on chronic dialysis.

Underdiagnosis of diabetes mellitus in chronic dialysis patients on the renal transplant waiting list

In diabetic patients long-term patient and graft survival after renal transplantation is reduced compared to nondiabetic graft recipients. Incidence and prevalence of diabetic patients on dialysis is rising continuously; however, there is a surprisingly low prevalence of patients with known diabetes mellitus on our local renal transplant waiting list. In a retrospective study we clarified the underestimation of diabetic dialysis patients on the transplant waiting list. Our local waiting list includes 46 diabetic patients among 377 (12.2%) candidates. Nine patients had type 1 diabetes and 37 type 2 diabetes. Surprisingly, only 20 of 37 patients (ie, 54%) were initially (at the time of wait-listing) classified as (type 2 diabetes mellitus). Primary renal disease in these 17 diabetic patients was classified in only eight patients, whereas the remaining nine were considered as chronic glomerulonephritis (not biopsy-proven and diabetic nephropathy not excluded). We conclude that among uremic patients on the renal transplant waiting list, the prevalence of diabetes mellitus and the number of patients with diabetic nephropathy are notably underdiagnosed.

[Uremic patients--late referral, early death]

BACKGROUND AND OBJECTIVE

A number of reports from various countries document that patients with renal failure who are referred late to renal units, have more complications e. g. lack of vascular access when dialysis has to be started as well as longer hospitalisation and have also a higher risk of early death. No data on these points are available from Germany.

PATIENTS AND METHODS

In a retrospective analysis the timing of referral to the nephrologists was studied in two Departments of Medicine, e. g. Heidelberg and Vienna, for all patients who started renal replacement therapy. For patients in Heidelberg the relation between timing of referral and survival on dialysis was analysed using the Kaplan-Maier-technique.

RESULTS

In Heidelberg 280 patients were analysed, 174 men, 106 women, age 61.8 +/- 14.5 years; 136 diabetic patients (9 type 1). They had been referred from GPs (n = 131), specialists (diabetologists, cardiologists; n = 20), emergency departments (n = 33), other hospitals (n = 90) or other institutions (n = 16). The measured median creatinine clearance at the time of referral was 14 ml/min (5-34). The median interval between referral and start of dialysis was 17 weeks. 137 patients had been referred < 17 weeks and 143 patients > or = 17 weeks prior to the start of dialysis. 97 of the 111 patients referred < or = 4 weeks prior to dialysis and 59 of the 169 patients referred > 4 weeks had to be dialysed with a central catheter. There were clear differences in patient survival. In patients referred < 17 weeks before the start of dialysis, the actuarial risk of death during the first 12 month was 34.2 % compared to 5.5 % (p < 0.0001) in patients referred > or = 17 weeks. Even the mortality in the interval between 12 and 24 months after the start of dialysis was clearly higher (15.3 %) in patients with late compared to early referral (11.4 %).

CONCLUSION

Late referral of patients with impaired renal function to renal units causes more frequent problems of vascular access, longer hospitalisation, more medical complications, higher costs and higher mortality. Early referral of patients with renal failure is indispensable to improve dialysis outcomes.

[Acute renal failure and hypertension crisis after a technoparty]

HISTORY

A 22 year old patient had noted progressive flank pain without recognizable urinary abnormalities for five days.

INVESTIGATIONS

A urologist had noted increased serum creatine (2.1 mg/dl), hypertension (180/100 mmHg) and microhematuria. A post-renal cause was excluded by excretory urography. An interview revealed that the patient had consumed cocaine on weekends since age 19; the acute episode was preceded by a rave party with consumption of a total of 3 g of street quality cocaine.

DIAGNOSIS AND TREATMENT

Because of microhematuria with a suggestive nephritic urinary sediment, the patient underwent renal biopsy. It showed acute tubular necrosis and interstitial edema, but no signs of glomerulonephritis and negative immunohistology. The patient received antihypertensive treatment. This led to rapid reversal of elevated serum creatinine and microhematuria was noted, but hypertension persisted. Currently the patient receives ACE inhibitors.

CONCLUSION

Similar to what is seen in the US, cocaine use has to be considered in the differential diagnosis of acute renal failure with hypertension.

Hypertension after renal transplantation

With current immunosuppression elevated blood pressure is found in almost 90% of renal graft recipients. Major causes of this finding are impairment of renal function, secondary to chronic allograft nephropathy or (less frequently) recurrence of primary renal disease, the use of calcineurin inhibitors as immunosuppresants, uncontrolled renin secretion by the shrunken kidneys of the recipient, stenos- ing lesions of the transplant artery (or the upstream arteries of the recipient), polycytemia and (genetic predisposition to) hypertension of the graft donor. Even minor degrees of blood pressure elevation have a significant impact on survival of the recipient and on graft survival, presumably by amplifying vascular injury to the graft. In this respect, elevation of systolic blood pressure and an abnormal circadian blood pressure profile are of particular relevance. In contrast to previous opinion, ACE inhibitors are indicated in the treatment, but, given the causal role of sodium retention in graft vasoconstriction, diuretics and calcium channel blockers remain main stays of antihypertensive treatment in the renal allograft recipient.

Treatment of life-threatening multiresistant staphylococcal and enterococcal infections in patients with end-stage renal failure with quinupristin/dalfopristin: preliminary report

BACKGROUND

Life-threatening infections with multiresistant gram-positive bacteria are increasing. Treatment with quinupristin/dalfopristin (Q-D) has turned out to be effective against such resistant pathogens.

PATIENTS AND METHODS

We report on treatment of six patients on dialysis (four with additional liver injury) and of one renal graft recipient with normal renal function who had severe infections caused by multiresistant Staphylococus epidermidis (1/7), methicillin-resistant Staphylococcus aureus (4/7) and vancomycin-resistant Enterococcus faecium (2/7).

RESULTS

Six out of seven patients were cured by therapy with Q-D in adjusted doses lasting for 10 to 34 days. Pharmacokinetics of Q-D and its metabolites were determined and remained within the therapeutic range, despite a modest increase of all compounds at the presumed steady state. The concentrations of the metabolites of Q-D were clearly lower than the parent drugs, including those of quinupristin-conjugated derivatives, which has not been reported previously.

CONCLUSION

These preliminary results suggest that: a) neither quinupristin nor dalfopristin or its metabolites accumulated despite the long duration of treatment; b) no adjustment of the standard dosage regimen (three times 7.5 mg/kg/day) is necessary in end-stage renal disease.

Hypertension after renal transplantation

With current immunosuppression, elevated blood pressure is found in almost 90% of renal graft recipients. Major causes of this are impairment of renal function, secondary to chronic allograft nephropathy or less frequently recurrence of primary renal disease, the use of calcineurin inhibitors as immunosuppressants, uncontrolled renin secretion by the shrunken kidneys of the recipient, stenosing lesions of the transplant artery (or the upstream arteries of the recipient), polycytemia and (genetic predisposition) to hypertension of the graft donor. Even minor degrees of blood pressure elevation have a significant impact on survival of the recipient and on graft survival, presumably by amplifying vascular injury to the graft. In this respect elevation of systolic blood pressure and an abnormal circadian blood pressure profile are of particular relevance. In contrast to previous opinion, ACE inhibitors are indicated in the treatment, but, given the causal role of sodium retention and graft vasoconstriction, diuretics and calcium channel blockers remain mainstays of antihypertensive treatment in the renal allograft recipient.

Blood pressure after renal transplantation

Hypertension is extremely common in renal allograft recipients, mainly as the result of impaired renal function and cyclosporin A therapy. Blood pressure is a powerful independent predictor of longterm graft outcome. This adverse effect is presumably mediated by both hemodynamic and non-hemodynamic factors. There is also evidence for activation of the renin angiotensin system in the renal allograft. Antihypertensive treatment is of known benefit on graft outcome in experimental models, but this has so far not been documented in clinical trials. Proteinuria is another independent predictor of longterm graft outcome. There is recent documentation of a specific antiproteinuric effect of ACE inhibitors on proteinuria which is of interest since proteinuria is an independent predictor of longterm graft outcome.