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B Vogt

Publications and source records attributed to B Vogt.

At least 19 recordsLinked to original sources
PubMed2006

BOLD-MRI for the assessment of renal oxygenation in humans: acute effect of nephrotoxic xenobiotics.

Hypoxia of renal medulla is a key factor implicated in the development of drug-induced renal failure. Drugs are known to influence renal hemodynamics and, subsequently, affect renal tissue oxygenation. Changes in renal oxygenation can be assessed non-invasively in humans using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI). This study was designed to test the acute effects of administration of specific drugs in healthy human kidney oxygenation using BOLD-MRI. Acute changes in renal tissue oxygenation induced by the non-steroidal anti-inflammatory drug indomethacin, the iodinated radio-contrast media (RCM) iopromidum, and the calcineurin inhibitors cyclosporine micro-emulsion (CsA-ME) and tracrolimus were studied in 30 healthy volunteers. A modified Multi Echo Data Image Combination sequence was used to acquire 12 T(2)(*)-weighted images. Four coronal slices were selected to cover both kidneys. The mean R(2)(*) (1/T(2)(*)) values determined in medulla and cortex showed no significant changes induced by indomethacin and tacrolimus administration. CsA-ME decreased medullary (P=0.008) and cortical (P=0.004) R(2)(*) values 2 h after ingestion. Iopromidum caused a significant increase in medullary R(2)(*) within the first 20 min after injection (P<0.001), whereas no relevant changes were observed in renal cortex. None of the measurements showed left-right kidney differences. Significant differences in renal medullary oxygenation were evidenced between female and male subjects (P=0.013). BOLD-MRI was efficient to show effects of specific drugs in healthy renal tissue. Cyclosporine increased renal medullary oxygenation 2 h after ingestion of a single dose, whereas indomethacin and tacrolimus showed no effect on renal oxygenation. Injection of iodinated RCM decreased renal medullary oxygenation.

Adolescent↗
PubMed2006

[Obesity: what impact on renal function?].

The increasing prevalence of obesity is a major public health concern, affecting more than one third of the Swiss population. The renal effects of obesity per se, independent of hypertenison or diabetes, though, are less known. Obesity is positively correlated with proteinuria and the development of glomerulomegaly and focal segmental glomerulosclerosis. The pathophysiology of the obesity-associated kidney disease is complex, including hemodynamic and physical factors and increased synthesis of vasoactive and fibrogenic substances by adipose tissue. The most important therapeutic approach is weight reduction. Angiotension converting enzyme (ACE) inhibition is effective in reducing proteinuria, but longer follow-up is required to determine the long term benfits of ACE inhibition.

Humans↗
PubMed2006

Efficacy and safety of enteric-coated mycophenolate sodium (myfortic) in de novo renal transplant recipients: results of a 12-month multicenter, open-label, prospective study.

Enteric-coated mycophenolate sodium (EC-MPS) has been developed as an alternative formulation of mycophenolate acid aiming for improved gastrointestinal (GI) tolerability. This 12-month, open-label, multicenter, prospective study investigated the efficacy and tolerability of EC-MPS (720 mg twice a day) given in combination with cyclosporine microemulsion (CsA-ME) in de novo renal transplant recipients (n=140). The efficacy evaluation was the incidence of treatment failure (defined as biopsy-proven acute rejection [BPAR], graft loss, or death) after 6 and 12 months of treatment. The incidences of treatment failure, BPAR, and graft loss were comparable at 6 and 12 months (18.6% vs 22.1%, 15.7% vs 19.3%, and 1.4% vs 2.1%, respectively). Renal function at 6 and 12 months (creatinine clearance) was 60.6+/-19.8 mL/min and 63.2+/-27.1 mL/min, respectively. EC-MPS was generally well tolerated; 95.9% of the reported GI adverse events (AEs) were rated as mild or moderate. The rate of EC-MPS dose reduction was 26.4%; 4.3% were due to GI AEs. The rate of EC-MPS dose interruption was 10%; 2.1% were due to GI AEs. In summary, EC-MPS given in combination with CsA-ME demonstrates good efficacy and tolerability in de novo renal transplant recipients.

Adult↗
PubMed2006

[Crystalluria].

Crystalluria is often present in routine urinalysis. The precipitation of crystals occurs in supersaturated urine. "Non-specific crystalluria" may be caused by food intake, pH and/or temperature changes of the urine, specially when urine is not analysed immediately. This randomly observed "non-specific crystalluria" is of no clinical value. In contrast, "specific" crystalluria can be associated with diseases such as nephrolithiasis, primary hyperoxaluria or ethylene glycol poisoning. Some drugs are excreted as crystals and may cause heavy crystalluria leading to kidney injury; this is the case of retroviral drugs and some antibiotics used in clinical practice. In these situations the diagnosis can be made by urinalysis and therapy be adapted accordingly. Important for the analysis of crystalluria is the correct handling of the fresh urine, knowledge of urinary pH and, of course, training in microscopic techniques.

Crystallization↗
PubMed2006

Successful kidney transplantation from donor with Marfan's syndrome.

Marfan's syndrome is caused by mutations in the extracellular matrix protein fibrillin-1 with aortic aneurysm and dissection being its most life-threatening manifestations. Kidney transplantation from donors with Marfan's syndrome has never been reported in the literature, possibly because of reticences due to the underlying connective tissue disease. Here, we report two patients with end-stage renal disease, transplanted with the kidneys from a donor with Marfan's syndrome who died of aortic dissection and cerebral hemorrhage. After delayed graft function in both recipients, renal function normalized with no renovascular complications and negative proteinuria for 6 years in one patient and 2 years in the other patient, who died from an ischemic cerebrovascular insult. Kidneys from organ donors with Marfan's syndrome might be suitable for transplantation.

Adult↗
PubMed2005

Kidney transplantation improves survival and is indicated in Fabry's disease.

BACKGROUND: Fabry's disease (FD) is an inborn error of glycosphingolipid catabolism with progressive systemic deposition of globotriaosylceramide thereby leading to renal and cardiac failure. Current therapy involves symptomatic medical management, dialysis, enzyme replacement therapy, kidney transplantation (KTx), and more recently gene therapy. Case fatalities occur in the fourth decade of life resulting from uremia unless dialysis or KTx is undertaken. STUDY DESIGN: This is a retrospective study aimed at determining the effect of KTx on the long-term outcome of patients with FD. RESULTS: Between 1964 and 1998, ten patients with FD received KTx at our institutions. Actuarial patient and graft survivals were 100% and 90% at 5 years; 76% and 66% at 10 years. One kidney graft was lost due to rejection. Patient survival data compared favorably at 5 years with survival of FD patients on hemodialysis alone (41%, P < .05). Five patients are alive at the time of this study, and five patients died with median survival time after KTx of 128 months (range: 74-160 months). CONCLUSIONS: This study demonstrates an excellent outcome in patients with FD in the first decade after KTx. In the absence of a severe contraindication, we advocate KTx to improve the overall prognosis of patients with renal failure due to FD. Based on the data, enzyme replacement therapy after KTx seems indicated, as FD progresses posttransplant, leading to case fatalities in the second decade after KTx.

Adolescent↗
PubMed2004

[Edema and the nephrotic syndrome].

If proteinuria is of sufficient amount, and persists for long enough, then a series of consequences arises which is called the nephrotic syndrome. The most notable consequence of massive proteinuria is salt and water retention leading to edema formation. This edema is found in association with proteinuria usually greater than 3.5 g/day, accompanied by hypoalbuminemia, usually less than 25 g/l. The underlying disease is usually a glomerulonephritis, albeit in rare situations severe renal artery stenosis can lead to proteinuria by hyperfiltration. Two theories have been proposed. In the classical "underfill" theory edema is considered to be secondary to salt retention resulting from renal hypoperfusion. According to this theory the primary event is the decrease in plasma volume due to the diminution of plasma oncotic pressure resulting from hypoalbuminemia, causing transfer of fluid from the plasma to the interstitial space "underfilling" the blood compartment and resulting to secondary renal sodium retention. This mechanism applies mainly to the nephrotic syndrome associated with minimal change disease observed in children. By contrast, in most adults with the nephrotic syndrome due to minimal change disease or other glomerular lesions such as membranous or proliferative glomerulonephritis, an initial plasma volume expansion is observed. Therefore, the primary event responsible for the sodium retention is a renal intrinsic excretory defect, which leads to extracellular fluid expansion and edema formation. Therapy is specific for the specific glomerular disease and symptomatic for the edema (diuretics), anticoagulation therapy for prevention of venous thrombosis and embolism, antibiotics for infections, and most of all, omission of triggering factors such as specific xenobiotics.

Adult↗
PubMed2004

[Rasburicase (Fasturtec)].

Rasburicase (Fasturtec) is an enzyme that transforms uric acid to the more water soluble allantoin to be excreted by the kidneys. Rasburicase fulfills an unmet clinical need in the treatment of hyperuricemia in that it produces a more rapid action of controlling serum uric acid compared with allopurinol. Tumours with high proliferative rate and sensitive to chemotherapy such as hematological malignancies (mainly) solid tumours (occasionally) may lead to a tumor lysis syndrome. In this situation rasburicase can effectively lower serum uric acid concentrations with a secondary improvement in renal function. Hyperuricemia is the hallmark of severe gout with tophi formation. Rasburicase represents an interesting new option in controlling serum uric acid in patients with severe tophaceous gout.

Crystallization↗
PubMed2003

Standardization of two immunological HbA1c routine assays according to the new IFCC reference method.

The measurement of HbA1c is meanwhile well established as the most important parameter in clinical chemistry for monitoring the long term metabolic control of diabetic patients. However, the comparability of HbA1c values obtained by different methods in different laboratories and different countries is limited since there was no internationally agreed reference method available. Additionally the % HbA1c values, based on the most common DCCT values are too high due to well known non specificity of the DCCT standardization protocol. Recently a new reference method for the determination of HbA1c was developed and has been approved by the IFCC as the future basis for the worldwide standardization of HbA1c routine assays. The two routine methods from Roche Diagnostics (both based on the immunoturbidimetric determination of the stable glucose adduct to the N-terminal group of the hemoglobin beta chain, Roche-Hitachi/Tina-quant [a] and COBAS INTEGRA) are directly standardized against this new reference method. Both routine methods are based on a two step approach: in a first step the total Hb is quantified by a colorimetric method and in a second step the stable glucose adduct to the N-terminal group of the hemoglobin beta chain is quantified by immunoturbidity (HbA1c mass). Consequently, first the standardization of the total Hb assay was reconfirmed by method comparisons against the cyanomethemoglobin reference method. Second, the standardization of the HbA1c mass was done by running method comparisons against the new IFCC reference method. The resulting new calibrator values for HbA1c [mass] and total Hb [mass] allow a direct estimation of % HbA1c according to IFCC just by calculating the HbA1c [mass]/total Hb [mass] ratio. Good linear correlations were obtained when comparing the routine methods against the new IFCC reference, indicating the high specificity of these immunological approaches. The following correlations are obtained: Hitachi / Tina-quant [a] (Y) versus IFCC reference method (X): Y = -0.031 + 1.009 x X; r = 0.995. COBAS INTEGRA (Y) versus IFCC reference method (X): Y = -0.156 + 1.006 x X; r = 0.997. Hitachi / Tina-quant [a] (Y) versus Integra (X); (both standardized according to IFCC): Y = 0.057 + 1.003 x X; r = 0.997. The HbA1c values obtained with this new IFCC standardization are significantly lower than the well known DCCT values. Due to the specificity of the immunological approach which is very close to the analyte as defined by the IFCC reference method, no further corrections of the obtained % HbA1c values are necessary. A slope/intercept correction formula is derived which allows the transformation of IFCC values into the DCCT numbers if requested.

Blood Chemical Analysis↗
PubMed2002

Search for physical interaction between BICP0 of bovine herpesvirus-1 and p53 tumor suppressor protein.

The immediate-early (IE) protein BICP0 of bovine herpesvirus-1 (BHV-1) may have other functions besides transactivation of viral promoters. Recently, we observed that BICP0, delivered to cultured cells by a helpervirus-free amplicon system, forms spherical or doughnut-like structures in which the tumor suppressor protein p53 is sequestered. The objective was to determine whether BICP0 and p53 interact physically, we used both yeast and mammalian two-hybrid systems. As a bait plasmid, pVA3 which encodes a hybrid protein consisting of the Gal4 DNA binding domain fused to murine p53 was used. The BICP0 gene or its truncated versions were inserted into the prey plasmid pGAD424. Bait and prey plasmids were cotransformed into yeast strain Y153, which has LacZ and HIS3 reporter genes under the control of Gal4 upstream activating sequence. After 4-6 days, colonies were stained for beta-galactosidase activity. In the mammalian two-hybrid system, pM-53 was used as a bait where truncated p53 fused to Gal4 DNA binding domain is expressed. The BICP0 gene was cloned into prey plasmid pVP16. The interaction between p53 and SV40 T-antigen was evaluated as a positive control in both systems. Neither full-length BICP0 nor its truncated derivatives induced beta-galactosidase activity in yeast whereas the positive control turned blue under the same conditions. The mammalian two-hybrid system, in which chloramphenicol acetyltransferase (CAT) activity was used as a reporter, also failed to show an interaction between these two proteins. Co-localization of p53 with BICP0 in spherical structures is unlikely to result from a direct physical interaction between these two proteins. Mediation by additional cellular proteins may be required.

Animals↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMed2002

The effect of the 5-HT3 receptor antagonist, alosetron, on brain responses to visceral stimulation in irritable bowel syndrome patients.

AIM: To conduct a placebo-controlled functional brain imaging study to assess the effect of the 5-hydroxytryptamine-3 receptor antagonist, alosetron, on irritable bowel syndrome symptoms, regional brain activation by rectosigmoid distension and associated perceptual and emotional responses. METHODS: Fifty-two non-constipated irritable bowel syndrome patients (28 female) were enrolled in a randomized, placebo-controlled trial with alosetron (1-4 mg b.d.). Thirty-seven patients completed both brain scans following randomization. Rectosigmoid stimulation was performed with a computer-controlled barostat. Changes in regional cerebral blood flow were assessed using H215O positron emission tomography. Stimulus ratings and changes in gastrointestinal symptoms were assessed using verbal descriptor scales. RESULTS: Alosetron, but not placebo, treatment was associated with a decrease in symptom ratings, and reductions in emotional stimulus ratings. Compared to baseline, alosetron treatment was associated with reduced regional cerebral blood flow in bilateral frontotemporal and various limbic structures, including the amygdala. Compared to placebo, decreases in activity of the amygdala, ventral striatum, hypothalamus and infragenual cingulate gyrus were significantly greater after alosetron. CONCLUSIONS: In non-constipated irritable bowel syndrome patients, 3 weeks of treatment with a 5-hydroxytryptamine-3 receptor antagonist decreases brain activity in response to unanticipated, anticipated and delivered aversive rectal stimuli in structures of the emotional motor system, and this is associated with a decrease in gastrointestinal symptoms.

Adult↗
PubMed2002

Glucocorticoids and 11 beta-hydroxysteroid dehydrogenase type 2 gene expression in the aging kidney.

BACKGROUND: Aging is associated with increased concentrations of circulating glucocorticoids, a situation expected to induce a glucocorticoid-mediated mineralocorticoid effect, resulting in sodium retention and hypertension unless counteracting mechanisms are operative. Conversion of glucocorticoids to inert 11 beta-keto compounds by the enzyme 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD2) is one of these mechanisms. We hypothesized therefore that 11 beta-HSD2 gene expression and/or activity increase with age in male WAG/Rij rats, a strain without increased blood pressure with age or senescence-related obesity or kidney disease. MATERIALS AND METHODS: Corticosterone (B) concentrations in plasma and urinary excretion of corticosterone and dehydrocorticosterone (A) tetrahydro metabolites, THB + 5 alpha-THB + THA, were assessed by gas chromatography-mass spectrometry (GC-MS) in 10-month-old-rats (n = 6) and in 30-month-old rats (n = 6). Renal 11 beta-HSD2 messenger ribonucleic acid (mRNA) abundance was measured by real-time quantitative TaqMan polymerase chain reaction and microarray assays. RESULTS: Thirty-month-old rats had significantly higher corticosterone concentrations in plasma and increased urinary excretion of corticosterone and dehydrocorticosterone tetrahydro metabolites. Conversion of B to A in kidney microsomes from 30-month-old rats was moderately but not significantly increased compared with 10-month-old rats. The urinary ratios of (THB + 5 alpha-THB)/THA and free B/A and renal 11 beta-HSD2 mRNA abundance were equal in 10- and 30-month-old rats. CONCLUSIONS: There is no evidence for an enhanced gene expression or activity of renal 11 beta-HSD2 in these aging rats, suggesting either that endogenous 11 beta-HSD2 is able to cope with the increased corticosterone concentrations characteristic of the aging process or that alternative mechanisms contribute to the maintenance of a normal sodium excretion in these animals.

11-beta-Hydroxysteroid Dehydrogenase Type 2↗
PubMed2001

Prophylactic hemodialysis after radiocontrast media in patients with renal insufficiency is potentially harmful.

PURPOSE: Acute renal failure induced by contrast media is an important cause of hospital-acquired renal insufficiency. Preexisting renal failure and the dose of contrast media are known risk factors for the development of radiocontrast nephropathy. We performed a randomized trial to test whether radiocontrast nephropathy can be avoided by prophylactic hemodialysis immediately after the administration of contrast media in patients with impaired renal function. SUBJECTS AND METHODS: Renal function and other parameters, hemodialysis requirement, and relevant clinical events were recorded before and during the 6 days after administration of contrast media in 113 patients with a baseline serum creatinine level >200 microm/L (>2.3 mg/dL). Patients were randomly assigned to either hemodialysis (n = 55) or nonhemodialysis (n = 58) treatment after parenteral low-osmolality contrast media. RESULTS: The characteristics of the patients in the two groups were similar. Compared with baseline levels, the mean [+/- SD] serum creatinine level decreased at day 1 (277 +/- 95 microm/L), peaked at day 4 (353 +/- 126 microm/L), and returned to baseline at day 6 (327 +/- 119 microm/L, P <0.05 by analysis of variance) after administration of contrast media in the hemodialysis group, whereas in the nonhemodialysis group, no significant changes in mean serum creatinine level were observed. Eleven patients required 1 or more hemodialyses (8 in the hemodialysis group and 3 in the nonhemodialysis group, P = 0.12), 6 of whom (4 vs. 2, P = 0.44) required 3 or more hemodialyses. Clinically relevant events included pulmonary edema (1 vs. 4 patients, P = 0.36), myocardial infarction (2 vs. 2), stroke (2 vs. 0, P = 0.24), and death (1 vs. 1). CONCLUSIONS: The strategy of performing hemodialysis immediately after the administration of low-osmolality contrast media in all patients with a reduced renal function did not diminish the rate of complications, including radiocontrast nephropathy.

Acute Kidney Injury↗
PubMed2001

Sirolimus-associated eyelid edema in kidney transplant recipients.

BACKGROUND: The immunosuppressant sirolimus is effective in preventing acute rejection episodes. So far, unusual edema formation has not been reported as a side effect. METHODS: Two groups of patients with renal transplants, consisting of 11 patients each, were followed for up to 29 months. The immunosuppressive regimen was either sirolimus and prednisone with or without cyclosporine or azathioprine/mycophenolate and prednisone with cyclosporine. Routine follow-up included a thorough clinical investigation. Edema formation was documented photographically. RESULTS: In 5 of the 11 patients treated with sirolimus uni- or bilateral, non-itching, eyelid edema was observed. After discontinuation of sirolimus, lid edema disappeared. The duration until recovery varied from weeks to months. No cause of edema formation other than the treatment with sirolimus was detected. CONCLUSIONS: Severe eyelid edema formation seems to be associated with sirolimus treatment. The underlying mechanism is unknown.

Adolescent↗
PubMed2001

Lack of superinfection interference in retroviral vector producer cells.

Vesicular stomatitis virus G protein (VSV-G)-pseudotyped retroviral vectors have become more feasible for clinical gene transfer protocols since stable tetracycline (tet)-regulated packaging cell lines have become available. Here, we analyzed superinfection interference in VSV-G-pseudotyped and classic amphotropic packaging cell lines. No superinfection interference was observed in VSV-G-pseudotyped packaging cell lines. Thus, integrated retroviral vector genomes accumulated during culture. Similar results were obtained with the amphotropic packaging cells, but to a lesser degree. In addition, VSV-G packaging cells were susceptible to infection with vector particles devoid of envelope proteins, which are produced by these cells in high titers when VSV-G expression is suppressed by tetracycline. For both packaging systems, superinfection could be blocked by azidothymidine (AZT). With regard to safety, this study suggests that in clinical protocols amphotropic producer clones should be tested for superinfection interference and VSV-G packaging cells should always be cultured in the presence of AZT.

Cells, Cultured↗