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T Ebert

Publications and source records attributed to T Ebert.

At least 55 records · Page 3Linked to original sources
PubMed1995

Angiocentric lymphoma of the kidney in the acquired immunodeficiency syndrome.

Angiocentric lymphoma, which is the malignant counterpart of angiocentric immunoproliferative lesions, comprises a rare group of non-Hodgkin's lymphomas of T-cell origin. It is characterized by marked invasion and destruction of small vessels by lymphomatoid cells, predominantly in the lungs. The prognosis is poor and many patients die within several months. To our knowledge primary involvement of the genitourinary tract has not been previously reported. We report a case of a solitary primary angiocentric lymphoma of the kidney in a patient with the acquired immunodeficiency syndrome. Therapy consisted of nephrectomy without adjuvant treatment. Histological characteristics as well as diagnostic and therapeutic options are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Dual-parameter immunoflow cytometry--a new technique in the noninvasive diagnosis of bladder cancer.

The introduction of monoclonal antibodies into the diagnosis of transitional cell carcinoma (TCC) has been a further step toward the use of biological parameters to support conventional cytological diagnosis of this tumor entity. Several investigators have demonstrated the high sensitivity and good specificity of immunocytology. Nevertheless this technique is hampered by the inconvenient and time-consuming microscopic analysis. The purpose of this study was to combine the advantages of immunocytology with the capabilities of an automated flow-cytometric system. Since all monoclonal antibodies (mAbs) currently used for immunocytology cross-react with granulocytes a preselection of urothelial cells becomes necessary for immuno-flow cytometry (immuno-FCM). Based on earlier analyses mAb Due AUT 2, reactive against urothelium and not against granulocytes, was chosen to preselect for urothelial cells. mAb Due ABC 3 was used to discriminate between normal and malignant urothelial cells. Initial experiments including 10 barbotage specimens from patients with histologically proven TCC and concomitant urinary tract infection yielded a high sensitivity (90%) of immuno-FCM. In 10 control patients with malignancies other than bladder TCC and benign diseases ABC 3 expression was not increased. Flow-cytometric examination of irrigation specimens from 10 patients with a history of bladder cancer but without cystoscopic and cytologic evidence of tumor recurrence showed abnormal results in 6 patients. Rebiopsy and/or cystectomy confirmed tumor recurrence in 5 of these patients and in 1 patient with negative immuno-FCM. Ongoing prospective trials will further define the clinical impact of this approach in the diagnosis and follow-up of patients with bladder cancer.

Antibodies, Monoclonal↗
PubMed1995

High-intensity focused ultrasound (HIFU) in the treatment of benign prostatic hyperplasia (BPH).

Transurethral resection of the prostate (TURP) and open adenectomy are regarded the golden standard in the management of patients with symptomatic benign prostatic hyperplasia (BPH). Various alternative treatment forms (microwaves, laser, radiofrequency, focused ultrasound) have been introduced recently. They all aim at reduction of morbidity related to TURP keeping a comparable efficacy at the same time. Since December 1992, 50 patients with BPH have been treated by high intensity focused ultrasound (HIFU-P) at our department. Six weeks following HIFU-P mean Qmax improved from 5.7 ml/s to 11.6 ml/s. Post voiding residual volume (RV) dropped from 215 ml to 100 ml, the International Prostate Symptom Score (IPSS) from 19.8 to 9.9. Both, IPSS and RV further improved during the following weeks. Follow-up data one year after treatment demonstrate that results remained stable in the majority of patients. Urinary tract infections were observed in 3 patients, macrohematospermia in all and macrohematuria (caused by the suprapubic catheter) requiring blood transfusion in 1 patient.

Aged↗
PubMed1995

[High energy focused ultrasound in treatment of benign prostatic hyperplasia].

Transurethral resection of the prostate (TURP) and open adenectomy are regarded the "golden standard" in the treatment of benign prostate hyperplasia (BPH). Various alternative treatment forms (microwaves, laser, radio frequency, focused ultrasound) have been introduced recently. They are all aimed at reducing the morbidity related to TURP while achieving comparable efficacy at the same time. Since December 1992, 35 patients with BPH have been treated with high-intensity focused ultrasound (HIFU-P) in our department. By 6 weeks after HIFU-P, mean Qmax had improved from 6.5 ml/s to 12.1 ml/s. Residual volume dropped from 207 ml to 95 ml, IPSS from 20.1 to 9.7. Both subjective as well as objective improvements remained stable after 3 and 6 months. Urinary tract infections were observed in 3 patients, macrohemato-spermia in all, and macrohematuria (caused by the suprapubic catheter) requiring blood transfusion in 1 patient.

Aged↗
PubMed1994

Lowered amounts of the tissue-specific transcription factor LFB1 (HNF1) correlate with decreased levels of glutathione S-transferase alpha messenger RNA in human renal cell carcinoma.

Human renal cell carcinoma is characterized by the loss of differentiation markers such as glutathione S-transferase alpha (GST-alpha). In this paper we show that the promoter of a GST-alpha gene contains a functional binding site for the cell-specific transcription factor LFB1 (HNF1). To investigate the potential role of LFB1 in the down-regulation of GST-alpha expression, we have compared the amount and the binding activity of the LFB1 protein between normal kidney and tumor tissue. By Western analysis and gel retardation assay using a monoclonal antibody specific for LFB1 we show that in 11 of 14 carcinomas the amount of LFB1 is clearly reduced compared to the corresponding normal tissue and that in all 14 renal carcinomas LFB1 binding activity is diminished. As in the same samples the abundance of GST-alpha mRNA is lower than in the normal tissue, we postulate that the loss of LFB1 binding activity might be responsible for the decreased expression of the GST-alpha gene in renal cell carcinoma.

Antibodies, Monoclonal↗
PubMed1994

P53 accumulation in precursor lesions and early stages of bladder cancer.

Recent investigations have demonstrated alterations of the p53 tumor-suppressor gene in a considerable number of transitional-cell carcinoma (TCC) specimens. Thus far, these investigations have been restricted to either papillary TCC or invasive bladder cancer. To obtain further information on a possible involvement of p53 in bladder cancer development or tumor progression, investigations of precursor lesions and early stages of this disease are required. Immunohistochemical examination of 6 dysplasias and 24 carcinomas in situ (TIS) showed p53 accumulation, which is suggestive of p53 inactivation, in 2 (33%) and 9 (38%) of these specimens, respectively. This ratio was similar in 9 T1 lesions (33%) and in 14 cases of muscle-infiltrative disease (35%). In papillary tumors, p53 accumulation was observed exclusively in 3/10 moderately differentiated or high-grade lesions but not in 1 Ta G1 tumor. The expression of p53 accumulation was a consistent finding. The examination of tumor recurrences yielded either the presence or the absence of p53 overexpression in the primary and recurrent tumors of 7/8 patients. Similarly, in multifocal TCC, p53 accumulation was also either present or absent in 10/11 cases examined. These results suggest the existence of at least two different subgroups of TCC, with p53 accumulation being present in one of these groups. The observation of p53 accumulation in dysplasia and in TIS is a prerequisite for a possible involvement of p53 in bladder cancer carcinogenesis, although it does not prove this assumption.

Carcinoma in Situ↗
PubMed1994

Expression of NAD(P)H:quinone oxidoreductase and glutathione S-transferases alpha and pi in human renal cell carcinoma and in kidney cancer-derived cell lines.

NAD(P)H:quinone oxidoreductase (NQOR) and glutathione S-transferases (GST) are enzymes of interest in cell defence and drug resistance. Relative levels of NQOR mRNA in renal cell carcinomas were 28 +/- 24% (n = 21) of those in non-neoplastic tissue and the enzyme activity decreased from 41 +/- 39 to 18 +/- 27 mU/mg protein (n = 23). In three of the cases, there was no measurable NQOR enzyme activity at all, indicating a polymorphism in the population for this gene. Relative GST-alpha mRNA levels in the tumours were on average 6 +/- 6% (n = 22) of the control value, whereas for GST-pi mRNA smaller decreases as well as increases were found in the tumours as compared to control tissue, but, on average, the level remained unchanged. Overall GST activity measured with CDNB as a substrate was 152 +/- 157 mU/mg protein in tumour tissue and 342 +/- 177 mU/mg protein in non-neoplastic tissue (n = 23). In all kidney tumour-derived cell lines NQOR mRNA was strongly expressed and on a per protein basis NQOR activity was about 10-fold higher than in the kidney tumour samples. GST-pi but not GST-alpha mRNA was also present. Total GST enzyme activities in these cell lines were similar to those in kidney tumour samples. HepG2 cells exhibited expression of NQOR and GST-alpha; GST-pi was not detectable. NQOR activity in HepG2 was about four-fold higher than in kidney-derived cell lines. Thus, NQOR and GST-alpha are both down-regulated in renal carcinoma, but their expression diverges in carcinoma cell lines.

Aged↗
PubMed1994

Imaging in the diagnosis and assessment of prognosis in localized prostate cancer. Consensus Conference on Diagnosis and Prognostic Parameters in Localized Prostate Cancer. Stockholm, Sweden, May 12-13, 1993.

As part of a WHO consensus conference on diagnosis and prognostic parameters in localized prostate cancer, a working group of experts discussed the role of various modern imaging techniques. Special attention was focused on transrectal ultrasound (TRUS) in combination with biopsies, magnetic resonance imaging (MRI) using endorectal coil and recent advances in these techniques. Some experimental techniques, especially hormone receptor scintigraphy and positron emission tomography were also discussed and new results were presented. We concluded that MRI seems to be superior to other imaging techniques in the preoperative assessment of local tumor stage. TRUS defends its place in the diagnostic armament; it is easily combined with multiple biopsies, the results of which are important in the assessment of the biological aggressiveness of prostate cancer. The present development in the field of nuclear medicine may result in techniques for in vivo characterization of tumors and will most certainly have important implications for diagnosis of prostate cancer in the future.

Animals↗
PubMed1993

[A study of the quantitative dual-parameter flow cytometry analyses of cellular antigens on transitional cells for the diagnosis of bladder cancer].

To establish a quantitative dual-parameter flow cytometry (FCM) analysis of cell surface antigens, possible obstacles caused by contaminated leucocytes in a specimen and staining and measuring conditions were investigated using human bladder cancer cell lines, 5637, T24 and SW1710. The first monoclonal antibody (MoAb) used to select urothelial cells in a specimen was applied with the second MoAb used to discriminate between normal and transformed urothelial cells. MoAbs Due AUT 2 and CD45 appeared to be suitable for the selection of urothelial cells, while Due ABC 3 and Due ABC 5 were applied to detect transformed cells. Tumor cell-leucocyte suspension was simultaneously stained with combinations of these MoAbs. The results demonstrated that Due AUT 2 and CD45 effectively eliminated contaminated leucocytes by means of positive and negative selection of the urothelial cells, respectively. Based on these experiments, dual-parameter FCM analyses of bladder washing from 5 patients with bladder cancer were performed using MoAbs Due AUT 2 and Due ABC 3. The results indicated that by dual-parameter FCM distinct antigenic features of transitional cells could be investigated even if considerable amounts of contaminated leucocytes were present. The clinical impact of this approach is a subject of ongoing trials.

Antibodies, Monoclonal↗
PubMed1993

[Immunotherapy of superficial bladder cancer].

Because patients with superficial bladder cancer are in a high-risk group where tumor progression is concerned, topical therapeutic strategies are necessary to prevent tumor recurrence and tumor progression. Based on experimental studies and several case reports, during the last two decades immunotherapy for superficial bladder cancer has been developed. The effects of topical instillation of bacillus Calmette-Guerin (BCG) has been carefully investigated in numerous clinical trials. Especially patients with carcinoma in situ appear to benefit from BCG therapy. Other types of local immunotherapy, e.g., instillation of interferons, interleukins, and keyhole limpet hemocyanin have been found to have fewer side effects than BDG. These new approaches are currently under clinical investigation.

Administration, Intravesical↗
PubMed1992

Monoclonal antibody Due ABC 3 directed against transitional cell carcinoma. I. Production, specificity analysis, and preliminary characterization of the antigen.

The development of the hybridoma technology allows the identification of tumor associated antigens with monoclonal antibodies (mAbs). Employing this technology mAb Due ABC 3 was obtained by immunization of a BALB/c mouse with bladder tumor cell line SW 1710 and subsequent cell fusion of spleen cells with P3. X63.Ag8.653 mouse myeloma cells. MAb Due ABC 3, an IgM antibody, was found to recognize an antigen present in the membrane of tumor cells in 25 out of 28 (89%) transitional cell carcinoma specimens but rarely (three out of 25 specimens, 12%) on normal urothelial cells. Cross reactions were seen with proximal tubular epithelium of the kidney and seven out of 12 renal cell carcinomas examined. Furthermore, the antigen was expressed by granulocytes, some gastrointestinal epithelia, ovarian and breast carcinoma. The antigen recognized by mAb Due ABC 3 was stable to fixation with formaldehyde and paraffin emmbedding, different proteases, alkaline treatment and heat exposure up to 70C. Antigenicity was abandoned by incubation with periodate but not with neuraminidase treatment. The antigen could be extracted with chloroform/methanol suggesting the involvement of a glycolipid. Immuno-thin layer chromatography revealed a single lipid band reacting with mAb Due ABC 3 but not with anti-CD15, directed against the Lewis X antigen. Although not tumor-specific, mAbs directed against differentiation antigens may be of value for the investigation of cell transformations as well as for diagnostic use.

Animals↗
PubMed1991

Assessment of clinical skills of residents utilizing standardized patients. A follow-up study and recommendations for application.

OBJECTIVE: To determine the reliability and validity of "standardized patients" to assess clinical performance of internal medicine residents. DESIGN: Each resident spent 2 half-days interacting with 19 standardized patients (nonphysicians taught to portray patients in a reproducible fashion). Each resident was asked to obtain focused histories, perform relevant physical examinations, and provide patient education or counseling. At the end of each 10- to 15-minute encounter, the resident was asked to identify positive findings on physical examination and to prioritize a differential diagnosis. Other, more traditional indicators of clinical skills were also obtained. PARTICIPANTS: Three hundred ten residents from nineteen internal medicine training programs in the New England region of the United States. RESULTS: Reproducible estimates of data gathering and interviewing skills were achieved with 1 day of testing. Validity analyses were difficult to interpret because of the lack of an external "gold standard." However, faculty judgments of performance from reviewing videotapes corresponded with standardized-patient-based scores. Differences in group performance were also demonstrated across years of training and between U.S. or Canadian and foreign medical graduates. CONCLUSIONS: Systematic and effective procedures for developing standardized-patient-based test materials and for training standardized patients have been developed. This technique is best used for measuring data gathering and interviewing skills. Correlations with commonly used evaluation methods were generally low; this may be because standardized patients measure different skills. Local use of this technique by residency programs and the development of regional consortia sharing resources, costs, and expertise are advocated.

Clinical Competence↗