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I Vollmer

Publications and source records attributed to I Vollmer.

6 recordsLinked to original sources
PubMed2001

Antidepressants do not modulate estrogen receptor alpha-mediated gene expression.

The estrogen receptor alpha has been shown to be activated both in a ligand-dependent and in a ligand independent fashion. We investigated whether antidepressants may directly activate the estrogen receptor alpha or enhance ligand-dependent or ligand-independent activation of the estrogen receptor alpha. Whereas both ligand-dependent and ligand-independent activation of the estrogen receptor alpha could be demonstrated in transient transfection studies, antidepressants neither directly activated the estrogen receptor alpha nor did they enhance ligand-dependent or ligand-independent activation. Thus, there are differences between the glucocorticoid receptor and the estrogen receptor alpha with regard to ligand-independent activation and action of antidepressants.

Animals↗
PubMed2000

Comparative methodological analysis of erbB-2/HER-2 gene dosage, chromosomal copy number and protein overexpression in breast carcinoma tissues for diagnostic use.

AIMS: This study was performed to test the validity of different methods for determining the status of the erbB-2/HER-2 oncogene in breast cancer tissues for diagnostic use. METHODS AND RESULTS: Forty formalin-fixed, paraffin-embedded breast carcinomas were investigated by fluorescence in situ and comparative genomic hybridization (FISH, CGH) as well as by immunohistochemistry (IHC) using Dako-HercepTest and CB11 antibody (Ventana). Additionally, competitive-differential polymerase chain reaction (cdPCR) was performed on frozen samples to estimate gene dosage alterations of erbB-2/HER-2. Amplification was detected in 12-23% and protein overexpression in 16-68% of the cases, depending on the methodology and/or the reagent used. Perfect concordance (100%) was found between the results of cdPCR and CB11-IHC, and a 97% concordance between FISH and CB11-IHC. The concordance between Dako-HercepTest and CB11-IHC was 78%: seven of eight 2+ carcinomas with the Dako-HercepTest were classified as nonamplified using FISH. CONCLUSIONS: Our results indicate that high-level expression as well as normal erbB-2/HER-2 status of breast carcinomas can be detected reliably both by IHC and gene dosage assessment in paraffin material for diagnostic use. However, borderline results, especially those with 2 + immunopositivity, should be interpreted with caution and increased emphasis should be given to other clinical and prognostic information available.

Adenocarcinoma↗
PubMed2000

Tacrolimus reversibly reduces insulin secretion in paediatric renal transplant recipients.

BACKGROUND: Conflicting reports exist about the mechanism of tacrolimus-induced post-transplant diabetes mellitus. METHODS: We analysed intravenous glucose tolerance tests (IVGTT) of 14 paediatric renal transplant recipients on cyclosporin (CsA) microemulsion and 15 patients on tacrolimus (FK506). The groups were similar in age (13.2+/-4.2 vs 13.0+/-3.7 years), body mass index, serum creatinine concentrations (96+/-60 vs 97+/-44 micromol/l), time after renal transplantation, and cumulative steroid dose over 12 weeks prior to the test (3.4 vs 3.5 mg/m(2)/day, NS, Mann-Whitney). Parameters of glucose tolerance included glucose, insulin, C-peptide concentrations, and HbA1c. The mean concentrations of the primary immunosuppressant were similar to treatments employed in other centres (CsA 165+/-59 ng ml and FK506 7. 5+/-2.2 ng ml). RESULTS: Baseline glucose concentrations were significantly higher on FK506 therapy compared with CsA microemulsion therapy. Baseline insulin concentrations and C-peptide concentrations were identical in both treatment groups. FK506 trough levels correlated negatively with k values (glucose constant decay) in the FK506 group. There was a significant reduction of the insulin first-phase concentrations, both after 1 min and after 3 min in the FK506 group compared with the CsA group (112+/-17 vs 237+/-57 microU/ml, P=0.034). In patients with repetitive IVGTTs, glucose constant decay and insulin production improved after lowering FK506 whole-blood trough levels. CONCLUSIONS: We conclude that post-transplant glucose intolerance could be due to a dose-dependent, direct effect of FK506 on the pancreatic beta cell function, which can be controlled by dose reduction.

Adolescent↗
PubMed1999

Diagnostic sensitivity of serum cystatin for impaired glomerular filtration rate.

Recently, the reciprocal of cystatin C (Cys-C), a non-glycosylated 13-kilodalton protein that is produced by all investigated nucleated cells, was found to correlate closely with glomerular filtration rate (GFR). In order to determine the diagnostic validity in children for the detection of impaired GFR, venous blood samples from 381 children (aged 1.7-18 years) with various renal pathology referred for 51Cr-EDTA clearance investigations were obtained for measurement of Cys-C as well as beta2-microglobulin (beta2-MG) and serum creatinine. Two hundred and sixteen children with clearance values >90 ml/min per 1.73 m2 constituted a control group, with a normal GFR. In the control group, Cys-C values were normally distributed with a mean of 0.94+/-0.27 mg/l and an upper reference limit (97.5th percentile) of 1.47 mg/l. In all children, there was a positive correlation between 51Cr-EDTA clearance and the reciprocal of Cys-C (r=0.64, P<0.0001), beta2-MG (r=0.59, P<0.0001), creatinine (r=0.55, P<0.0001), and the height/creatinine ratio (r=0.73, P<0.0001). Receiver-operating characteristics analysis showed that there were no significant differences between these three parameters for discriminating between patients with normal and reduced GFR, although there was a tendency towards the best diagnostic sensitivity of the GFR estimate according to the Schwartz formula. We conclude that for the detection of mildly impaired GFR, a full clearance study cannot be replaced by measurement of serum Cys-C or beta2-MG concentrations.

Adolescent↗
PubMed1999

Long-term prognosis of hemolytic uremic syndrome and effective renal plasma flow.

The long-term prognosis of diarrhea-associated hemolytic uremic syndrome (D+ HUS) was evaluated in a cohort of 127 of 149 children who had survived the acute phase. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were estimated by serial (51)Cr-EDTA and (123)iodine-hippurate clearances. All children had acute renal failure during the initial phase and 74% of patients were dialyzed. During the 1st year, mean GFR and ERPF increased continuously until a plateau was reached. In the 2nd year after the diagnosis of HUS, GFR was below 80 and ERPF below 515 ml/min per 1. 73 m(2) in 16% and 47% of patients, respectively. At the end of a median follow-up of 5.0 (range 2.0-13.2) years, the proportion of children with renal sequelae such as proteinuria >/=300 mg/l, hypertension, or a GFR <80 ml/min per 1.73 m(2) was 23%. Anuria of more than 7 days' duration and hypertension during the acute phase were statistically significant risk factors for an unfavorable outcome. A reduced ERPF in the 2nd year was found in 93% of patients with sequelae. Mean filtration fraction (SD) in these patients was 0. 26 (+/-0.07) versus 0.19 (+/-0.05) in patients without sequelae (P<0. 0001). These data suggest that loss of nephrons during the acute phase may implicate hyperfiltration in the residual functioning kidney mass leading to progressive renal disease. ERPF in the 2nd year after D+ HUS may serve as an excellent parameter to detect patients with a high risk of an unfavorable long-term outcome.

Child↗