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B Brandt

Publications and source records attributed to B Brandt.

At least 55 records · Page 3Linked to original sources
PubMed1998

Isolation of blood-borne epithelium-derived c-erbB-2 oncoprotein-positive clustered cells from the peripheral blood of breast cancer patients.

Clinical studies including thousands of breast cancer patients have shown that c-erbB-2 is amplified and overexpressed in 20-30% of invasive human breast cancers and that it is associated with distant metastasis in specified patient subgroups. To isolate and characterize hematogeneously spreading c-erbB-2-positive epithelium-derived cells from the peripheral blood of breast cancer patients, a combined buoyant density gradient and immuno-magnetic separation method has been used. The method utilizes a biotinylated anti-cytokeratin monoclonal antibody (MAb) for capturing the epithelium-derived cells. The expression of c-erbB-2 by the captured cells was detected using an anti-c-erbB-2 rabbit antibody (21N) coupled to an anti-rabbit gold-labeled anti-body, whereby immunoenzymatic cytokeratin staining was performed using a silver-enhanced immunogold double staining protocol. In total, 29 of the 46 patients tested had either cytokeratin (24/29) or cytokeratin/c-erbB-2 (19/29) positive clustered cells in their peripheral blood. We thus report here the presence and the frequency of clone-specifically stained clustered cells in the peripheral blood of breast cancer patients. The frequency of cytokeratin/c-erbB2 double-positive clustered cells in the peripheral blood was on average 10 times higher than that of double-positive single cells. The numbers of cytokeratin/c-erbB-2 double-positive clustered cells were positively correlated with the stage of tumors. Results of in vitro motility experiments using single and clustered cells from primary breast cancer tissue strongly support the assumption that cytokeratin/c-erbB-2 double-positive clustered cells have a high potential for locomotion. We suggest that blood-borne epithelium-derived c-erbB-2-positive clustered cells are the possible precursor cells responsible for the formation of distant metastases and bone marrow micrometastases.

Animals↗
PubMed1998

Analysis of a Streptomyces coelicolor A3(2) locus containing the nucleoside diphosphate kinase (ndk) and folylpolyglutamate synthetase (folC) genes.

A 3.6-kb DNA fragment from Streptomyces coelicolor A3(2) with the genes valS probably encoding a valyl-tRNA synthetase, folC encoding folylpolyglutamate synthetase, and ndk encoding a nucleoside diphosphate kinase was analysed. folC and ndk are separated by a small open reading frame of unknown function, orfX. The deduced folC gene product is a protein of 46,677 Da whose sequence is similar to other folylpolyglutamate synthetases and folylpolyglutamate synthetase-dihydrofolate synthetases from both Gram-positive and Gram-negative bacteria. After cloning folC behind the lacZ promoter, the Streptomyces folC complemented a folC mutant of Escherichia coli. An essential function for Streptomyces folC was suggested by the fact that it could not be mutated using a conventional gene disruption technique.

Amino Acid Sequence↗
PubMed1998

Selection of potentially metastatic subpopulations expressing c-erbB-2 from breast cancer tissue by use of an extravasation model.

Overexpression of the crbB-2 gene-encoded p185(c-erbB-2) is correlated with early onset of metastasis in breast cancer patients. Furthermore, the detection of blood-borne epithelium-derived clustered cells expressing p185(c-erbB-2) was related to advanced stages in breast cancer. To further elucidate the receptor's function in the metastatic process of human breast cancers, we analyzed disaggregated cells and cell clusters from freshly dissected breast cancer tissues. We studied whether their capability of extravasation is correlated with their expression of c-erbB-2. A model for the venular wall was constructed by growing human umbilical vein endothelial cells (HUVECs) on porous membranes coated with basement membrane extracellular matrix. In four control breast cancer cell lines (SK-BR-3, MCF-7, MDA-MB-468, and MDA-MB-468, the latter transfected with a full-length c-erbB-2 cDNA vector) producing different levels of the c-erbB-2 receptor, the expression level correlated positively with the invasiveness of the cells. The invasive, predominantly clustered cells from 14 of 23 tumors were positively stained for p185(c-erbB-2) by immunocytochemistry. Furthermore, we show that the invasive cell populations express the metastasis-associated proteins matrix metalloproteinase MMP-2, CD44, and integrins alpha(v)beta3 and alpha6. In this first study on the behavior of cells and cell clusters from disaggregated operated cancers in an extravasation model, we could demonstrate the presence of c-erbB-2-expressing cell subpopulations within the individual breast cancers that are presumably of high metastatic potential.

Blotting, Western↗
PubMed1998

Massive gross hematuria in a sickle cell trait patient with renal papillary necrosis. Conservative approach using a balloon ureteral catheter to tamponade the papilla bleeding.

We report the case of a patient with heterozygous sickle cell trait presenting with massive gross hematuria. Ureteroscopy revealed bleeding from the tip of papilla of the inferior calica and allowed us to tamponade the bleeding with a balloon ureteral dilator set (Cook(R) Urology). We show the value of the endourological approach in the conservative management of these patients at high risk of recurrent hematuria.

Adult↗
PubMed1997

Clinical and genomic influence of sulindac on rectal mucosa in familial adenomatous polyposis.

PURPOSE: A study was performed to evaluate the antiproliferative effects of low doses of the nonsteroidal drug, sulindac, on adenomas and rectal mucosa in familial adenomatous polyposis and to analyze the influence on tumor-suppressor genes and on apoptosis. METHODS: This was a prospective, controlled, nonrandomized Phase II dose-finding study for sulindac. The study group (n = 28) and control group (n = 10) underwent colectomy and ileorectal anastomoses, with repeated proctoscopy with endoluminal ultrasound and biopsies every three months. Dose-reduction of sulindac according to adenoma reversion was predetermined. Proliferation marker, Ki-67 (MIB1 and 5), on frozen or paraffin sections evaluated the antiproliferative effects; mutant p21ras, pantropic p53, mutant p53, and anti-bcl-2 were performed as enzyme-linked immunosorbent assay procedures and/or immunohistochemistry on paraffin sections. RESULTS: All patients responded to sulindac after 24 weeks (at the latest). There was a significant reduction of adenomas and dose reduction to 67 mg/day after three years of therapy (Mann's test for trend, P < 0.001). Results consisted of 78 percent complete reversions, 22 percent partial reversions of adenomas at latest re-examination, and no influence on upper gastrointestinal tract adenomas. No influence was detected on repeated hemograms, liver, or renal function at high or low doses. There was a permanent antiproliferative effect (Ki-67) of low-dose sulindac, significant blocking of ras mutation activation, and a significant difference of untreated and treated mucosa in mutant p53 content (Wilcoxon's or Kruskal-Wallis each, P < 0.05). Reverse correlation of anti-bcl-2 and p53 immunostaining on mucosa sections was an indication of adenoma relapse. CONCLUSIONS: Low-dose antiproliferative sulindac therapy is highly effective in adenoma reversion in familial adenomatous polyposis patients. Sulindac shows influence on tumor-suppressor genes and on apoptosis markers. An immunostaining correlation indicates adenoma relapse in flat microadenomas in advance of macroscopic appearance. Low-dose sulindac treatment may develop into an additive permnanent therapy for colectomized familial adenomatous polyposis patients.

Adenomatous Polyposis Coli↗
PubMed1997

[Molecular genetics and diagnosis of retinoblastoma. Significance for ophthalmologic practice].

Retinoblastoma (RB) is initiated by loss of function of both copies of the retinoblastoma susceptibility gene (RB 1). Hereditary predisposition to RB is caused by germline mutations in the RB 1 gene. Tumor formation is initiated by the somatic loss of the second allele. Most patients with hereditary RB develop multiple tumors that usually affect both eyes. In nonhereditary disease, however, both RB 1 mutations are somatic events that cause the formation of a single tumor focus. Knowledge of the germline mutation is often essential for accurate risk prediction. Applying strategies for efficient mutation detection, germline mutations can be identified in most individuals with hereditary RB. The vast majority of mutant alleles cause premature termination of translation owing to frameshift or nonsense mutations. In patients carrying these mutant alleles, penetrance is almost complete (> 95%) and numerous tumor foci are observed. However, some 5% of the mutations result in comparatively mild alterations at the protein level. Patients with mutations of this kind often show a lower mean number of tumor foci (reduced expressivity) or no tumor at all (incomplete penetrance). Reduced expressivity and incomplete penetrance are also observed in patients with large cytogenetic deletions. By mutation analysis in DNA from fresh frozen tumor samples and peripheral blood, we have detected RB 1 germline mutations in some 20% of patients with unilateral RB. These results emphasize the importance of molecular analysis in patients with isolated unilateral RB.

Chromosomes, Human, Pair 13↗
PubMed1997

Constitutional RB1-gene mutations in patients with isolated unilateral retinoblastoma.

In most patients with isolated unilateral retinoblastoma, tumor development is initiated by somatic inactivation of both alleles of the RB1 gene. However, some of these patients can transmit retinoblastoma predisposition to their offspring. To determine the frequency and nature of constitutional RB1-gene mutations in patients with isolated unilateral retinoblastoma, we analyzed DNA from peripheral blood and from tumor tissue. The analysis of tumors from 54 (71%) of 76 informative patients showed loss of constitutional heterozygosity (LOH) at intragenic loci. Three of 13 uninformative patients had constitutional deletions. For 39 randomly selected tumors, SSCP, hetero-duplex analysis, sequencing, and Southern blot analysis were used to identify mutations. Mutations were detected in 21 (91%) of 23 tumors with LOH. In 6 (38%) of 16 tumors without LOH, one mutation was detected, and in 9 (56%) of the tumors without LOH, both mutations were found. Thus, a total of 45 mutations were identified in tumors of 36 patients. Thirty-nine of the mutations-including 34 small mutations, 2 large structural alterations, and hypermethylation in 3 tumors-were not detected in the corresponding peripheral blood DNA. In 6 (17%) of the 36 patients, a mutation was detected in constitutional DNA, and 1 of these mutations is known to be associated with reduced expressivity. The presence of a constitutional mutation was not associated with an early age at treatment. In 1 patient, somatic mosaicism was demonstrated by molecular analysis of DNA and RNA from peripheral blood. In 2 patients without a detectable mutation in peripheral blood, mosaicism was suggested because 1 of the patients showed multifocal tumors and the other later developed bilateral retinoblastoma. In conclusion, our results emphasize that the manifestation and transmissibility of retinoblastoma depend on the nature of the first mutation, its time in development, and the number and types of cells that are affected.

Actuarial Analysis↗
PubMed1997

Competitive-differential polymerase chain reaction for gene dosage estimation of erbB-1 (egfr), erbB-2, and erbB-3 oncogenes.

Increases in the average gene copy number (AGCN) of the erbB oncogenes, especially the erbB-2 gene, have been found in a variety of human cancers. Such information is useful with respect to prognosis of the disease. Poor reproducibility and DNA damage complicate quantitative polymerase chain reaction (PCR)-based methods. Therefore, we describe a quantitative PCR method for the estimation of AGCN in the oncogenes erbB-1 (egfr), erbB-2, and erbB-3. The method comprises a competitive and differential PCR in a one-tube reaction (competitive-differential PCR, or cdPCR). Genomic sequences of the oncogene and the human beta-globin (HBB) reference gene and two competitors for the oncogene and reference gene were amplified with two primer pairs simultaneously. The competitors were chosen to be amplified with the same efficiency as the genomic sequences. Using this method, we confirmed egfr and erbB-2 amplification in cancer cell lines and tumor tissue, and we also detected erbB-3 amplifications. Furthermore, gene dosage decreases were detectable, e.g., an erbB-2 hemizygosity in MCF-7 cells. Thus, cdPCR facilitates the detection of both increases and decreases in AGCN with high reproducibility, sensitivity, and accuracy. This method is therefore suitable for clinical studies on erbB oncogene dosage deviations.

ErbB Receptors↗
PubMed1997

Assessment of radioisotopic micturating cystography for the diagnosis of vesicoureteric reflux in renal transplant recipients with acute pyelonephritis.

BACKGROUND: The gold standard for documenting vesicoureteric reflux is direct (retrograde) micturating cystography (MC). In children, radioisotopic MC has been advocated for increased sensitivity and lesser radiation exposure. In renal transplant recipients, where reflux can induce acute pyelonephritis, this technique has not been evaluated. The aim of this study was to assess the radioisotopic technique in these patients. METHODS: Seventeen renal transplant recipients had developed acute pyelonephritis following the surgical grafting procedure. They were investigated using both MC techniques. Radioisotopic MC was performed using 99mTc-pertechnetate. RESULTS: Reflux was documented in nine patients by radioisotopic MC but in only seven with the conventional technique. All negative patients remained symptom free after the pyelonephritis was cured and it was assumed that they had no reflux. Consequently, using the radioisotopic MC as gold standard, the conventional X-ray technique had a sensitivity of 78% and a specificity of 100%. CONCLUSIONS: Direct radioisotopic MC allowing continuous cystogram recording is more accurate than conventional X-ray MC for the diagnosis of vesicoureteric reflux in transplanted patients with acute pyelonephritis.

Acute Disease↗
PubMed1997

Comparison of prostate-specific antigen (PSA) measured by four combinations of free PSA and total PSA assays.

We compared prostate-specific antigen (PSA) assay systems [i.e., free PSA (f-PSA) and the corresponding total PSA (t-PSA) assay] from four different manufacturers as well as the f-PSA/t-PSA ratios with regard to their ability to discriminate between benign prostate hyperplasia (BPH) and prostate cancer (PCA). ROC analysis showed similar areas under the curves (AUCs) with different assay systems. For the entire patient population the AUCs of the f-PSA/t-PSA ratio were not or slightly increased compared with the sole measurement of t-PSA (t-PSA, 0.792-0.820; f-PSA/t-PSA ratio, 0.685-0.859). In contrast, for only those patients who showed t-PSA concentrations within the diagnostic gray area of 4-25 micrograms/L t-PSA, the AUCs were greater for the f-PSA/ t-PSA ratio than for measurement of t-PSA alone (t-PSA, 0.608-0.647; f-PSA/t-PSA ratio, 0.690-0.806). These results were confirmed by the predictive values of the negative results (NPVs) of the t-PSA assays and the f-PSA/t-PSA ratios (assay thresholds corresponding to a 95% detection limit). Compared with the sole t-PSA measurement there was no mentionable increase in the NPVs due to the f-PSA/t-PSA ratio for the entire patient population, but an increase up to 49% when limited to t-PSA concentrations within 4-25 micrograms/L. We therefore conclude that the f-PSA/t-PSA ratio may be helpful for differential diagnosis of BPH and PCA within the diagnostic gray area of 4-25 micrograms/L t-PSA.

Aged↗
PubMed1997

[Bilateral nephrectomy before renal transplantation in autosomal dominant polycystic renal disease].

Patients with autosomal dominant polycystic kidney disease are good candidates for renal transplantation, despite the fact that they are older at initiation of dialysis treatment. After grafting, the native polycystic kidneys are, however, at risk of infectious and hemorrhagic complications, in addition to patient's discomfort and technical difficulties with graft placement. We report on 10 successful cases of pretransplant binephrectomy performed in one time and analyse the risk factors of such a surgery. Nowadays, it appears that the disadvantages of an anephric state can be balanced by substitutive therapy. In conclusion, after this short series, we think that bilateral nephrectomy has to be considered in patients with autosomal polycystic kidney disease, especially when they have a prior history of renal infections and/or repeated hematurias.

Adult↗
PubMed1996

Isolation of prostate-derived single cells and cell clusters from human peripheral blood.

The detection of blood-borne prostate cancer (PCA) cells may help with clinical staging and the further understanding of PCA metastases. We discovered prostate-specific antigen (PSA)-positive stained but not PSA mRNA-expressing blood cells by means of cell sorting and PSA reverse transcription-PCR in patients. Therefore, we developed a cytokeratin immunomagnetic method to isolate PSA-positive epithelial cells from the circulating blood of PCA patients. We obtained blood-borne single cells from 6 of 10 PCA patients and clustered cells from 8 of 10 PCA patients. Patients with benign prostate hyperplasia tested negative for cell clusters. The reported isolation method yielded prostate-derived cells or clusters of them from PCA-diagnosed patients.

Humans↗
PubMed1996

Immunophenotyping of lymphocytes obtained by bronchoalveolar lavage: description of an all-purpose tricolor flow cytometric application.

A tricolor flow cytometric application is described which permits the determination of total T lymphocytes, T helper lymphocytes and cytotoxic T lymphocytes, natural killer cells and activated T lymphocytes under the same experimental conditions. Even when the lymphocyte count is low, when there is contamination by dust particles or when the cells are damaged the method works with high specificity and reliability. Lymphocytes are identified on the basis of their expression of the pan-leucocyte marker CD45, their side scatter, and plasma membrane integrity, assessed using the fluorescent DNA dye LDS 751. When lymphocyte subsets assessed by flow cytometry were compared with the standard immunoperoxidase method, a strong correlation was found for the CD3+, CD4+ and CD8+ cells. A weak correlation was found for CD25+ cells (r = 0.5). No correlation was seen for CD56+ cells. The high specificity of the procedure suggests that it could be used routinely for the analysis of lymphocytes in bronchoalveolar lavage fluid (BALF), especially when the BALF is contaminated by inorganic particles. Furthermore the application may contribute to the evaluation of lymphocyte subset analysis in the presence of low cell counts.

Bronchoalveolar Lavage Fluid↗
PubMed1996

Detection of the metastatic potential of blood-borne and immunomagnetically enriched epithelial cells by quantitative erbB-2 RT-PCR.

A quantitative competitive RT-PCR targeting the specific mRNA of c-erbB-2 is described. It is well known that in many cancers the c-erbB-2 gene dosage is elevated and/or the mRNA is overexpressed leading to a poor prognosis. The recently established method to enrich epithelial cells from peripheral blood made it reasonable and logical to develop a sophisticated competitive RT-PCR method to estimate the c-erbB-2 mRNA load of such cells. By this enrichment method it was discovered that cancer cells can be either isolated as single cells or clusters from patients' blood. The plausibility for their metastatic potential is derived from the measurement of the c-erbB-2 mRNA expression. A SKBR3 cell model suggested that the c-erbB-2 mRNA load is between 168 and 336 molecules per cell. Results of the quantitative competitive RT-PCR method can be used as a rational to determine the efficiency of anti-oncogenic therapies and as a criterion in adjuvant therapy decision.

Adenocarcinoma↗
PubMed1996

Fusion rate after posterior lumbar interbody fusion with carbon fiber implant: 1-year follow-up of 51 patients.

Problems associated with posterior lumbar interbody fusion (PLIF) have traditionally included the need for donor bone, prolonged healing time of donor bone, the difficulty of cutting precise bony channels, the risk of retropulsion of graft, postoperative collapse of the bone graft, and pseudarthrosis. To avoid these problems a carbon fiber reinforced polymer implant cage has been developed to facilitate interbody fusion. The aim of the present study was to evaluate the technical problems and fusion rate associated with these new device for PLIF. Between April 1991 and December 1993, 65 pairs of these implant cages were sold in Sweden. They were traced to six hospitals, where they had been used in the treatment of 51 patients operated on at a total of 65 levels. All PLIF were supplemented with VSP (Variable Screw Placement) instrumentation. All medical records were evaluated and all patients were examined with plain radiographs taken at least 1 year after surgery. If that investigation did not show a clear fusion they were also evaluated with CT (18 patients, 27 levels). No intraoperative problems with the device have been reported; 44 patients (86%) and 58 levels (89%) achieved successful fusion. All patients bar one maintained their immediately obtained postoperative disc height. CT with 1-mm slices and sagittal reconstruction is most helpful if radiographs are difficult to interpret.

Adult↗