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Biomedical subjects

T Ebert

Publications and source records attributed to T Ebert.

67 records · Page 4Linked to original sources
PubMed1991

Monoclonal antibody Due ABC 3 directed against transitional cell carcinoma. II. Prospective trial on the diagnostic value of immunocytology using monoclonal antibody Due ABC 3.

Recently, the development of monoclonal antibody Due ABC 3 directed against transitional cell carcinoma has been reported. With this monoclonal antibody an in vitro test system for diagnosis and followup of patients with transitional cell carcinoma has been developed. The clinical value of this assay, designated as quantitative immunocytology, was evaluated in a prospective trial and compared to conventional cytology. We investigated 74 voided urine specimens obtained from patients with histologically proved transitional cell carcinoma and 60 specimens from donors without clinical evidence of transitional cell carcinoma. Sensitivity was 66% versus 47% for immunocytology and conventional cytology. Specificity of conventional cytology (92%) was higher compared to immunocytology (58%). Statistical analysis demonstrated a significantly higher sensitivity of the combined analysis of conventional cytology and immunocytology (p less than 0.001) compared to conventional cytology alone, without significant differences in specificity. The results obtained with immunocytology were impaired by the great number of nonevaluable specimens. Poor preservation of cells, severe pyuria or an insufficient number of urothelial cells prevented evaluation in 25% of the cases, while only 6% could not be evaluated by conventional cytology. The ability of immunocytology to improve the sensitivity of conventional cytology makes this technique a promising adjunct to the noninvasive diagnosis of transitional cell carcinoma.

Antibodies, Monoclonal↗
PubMed1991

Accuracy of imaging modalities in staging the local extent of prostate cancer.

In this study, none of the evaluated clinical staging methods was found to predict reliably the presence or absence of extracapsular growth of histologically proved carcinoma of the prostate. In this respect, digital rectal examination, transrectal ultrasound, CT, and MR imaging cannot contribute to treatment decisions in localized prostate cancer. Further studies are under way to determine the value of 7.5-MHz scanners in transrectal ultrasound and high-resolution surface coils in MR imaging.

Biopsy↗
PubMed1990

Establishment and characterization of human renal cancer and normal kidney cell lines.

We have reviewed our laboratory's efforts to establish continuous human renal cancer cell lines. During the 16-year period of 1972 through 1987, 498 successive attempts resulted in establishment of 63 renal cancer cell lines. Of these lines, 46 were derived from primary kidney tumors and 17 from metastatic sites (lung, brain, bone, and lymph node). Forty-three of these lines have been characterized with regard to morphology, growth kinetics, anchorage-independent growth, tumorigenicity in athymic nude mice, and expression of kidney cell surface antigens. These results were compared with data from primary short term cultures of normal kidney epithelium. The overall success rate of establishing continuous renal cancer cell lines was 12.7%. In general, no significant difference in success was noted based on whether the specimen was derived from a primary or a metastatic lesion. However, all successfully established lines were derived from tumors exhibiting clinically "aggressive" behavior. All cell lines expressed proximal tubular cell differentiation antigens. Significant morphological heterogeneity was observed among normal kidney as well as kidney cancer cell lines in vitro. No significant difference in doubling time was found between cell lines of renal cancer and passage 1 cultures of normal kidney epithelium. Twenty-one of 30 (70%) lines assayed formed clones on soft agar and 26 of 33 (79%) lines grew in athymic mice. Among the 25 lines which were assayed for both soft agar growth and tumorigenicity in nude mice, this pair of phenotypic traits were concordant in 17 lines (60%). Four lines (16%) grew on agar but not in mice, while four other lines (16%) failed to grow in agar but were tumorigenic in mice.

Animals↗
PubMed1990

Immunodiagnosis of renal cell carcinoma.

Development of immunoassays for the diagnosis of RCC offers significant promise of improved clinical treatment of this disease. While this promise remains to be fulfilled, there is reason to believe that advances will soon be forthcoming. MABs have defined numerous kidney-associated antigens. In at least one instance (ADAbp), an immunoassay has already been established that aids in the diagnosis of benign renal diseases. A similar approach may also be useful in renal cancer. Likewise, in at least one instance a previously undefined peptide (the HHM factor) has been closed and sequenced. Synthesis of this peptide and production of antibodies to it cannot be far off. Measurement of this peptide and/or of the many other aberrantly produced peptides associated with this cancer may be anticipated to improve substantially our ability to diagnose early and, therefore, cure renal cancer.

Antibodies, Monoclonal↗
PubMed1990

[Biological markers in renal cell carcinoma].

The development of immunoassays for the diagnosis of renal cancer promises significant improvements in clinical treatment. Monoclonal antibodies have defined numerous kidney-associated antigens. In at least one instance (ADAbp), an immunoassay has already been established that is helpful in the diagnosis of benign renal diseases. A similar approach may also be useful in renal cancer. Similarly, in at least one instance a previously undefined peptide (HHM factor) has been cloned and sequenced. Synthesis of this peptide and the production of antibodies to it is imminent. The possibility of measuring this peptide and/or the many other aberrantly produced peptides associated with this cancer would presumably mean a substantial improvement in early diagnosis and therefore cure rates in renal cancer. The final role of chromosome changes in the diagnosis and determination of prognosis cannot yet be defined.

Biomarkers, Tumor↗
PubMed1989

The conservative treatment of osteonecrosis of the femoral head. A comparison of core decompression and pulsing electromagnetic fields.

Once roentgenographic changes are apparent, osteonecrosis of the femoral head in the adult generally progresses to osteoarthritis within two to three years. A variety of conservative surgical procedures have been devised to conserve the femoral head with varying success. This study examines the effectiveness of pulsing electromagnetic fields and core decompression in the treatment of osteonecrosis of the femoral head. Both techniques reduce the incidence of clinical and roentgenographic progression. Exposure to pulsing electromagnetic fields appears to be more effective in hips with Ficat II lesions than in hips with more advanced lesions.

Adult↗
PubMed1985

[Complications and late sequelae following radical cystectomy and supravesicle urinary diversion].

Until recently radical cystectomy combined with urinary diversion was only justified by most urologists as a therapeutic measure for the management of bladder cancer, when other forms of treatment failed controlling the disease. This attitude was mainly based on a high morbidity and mortality rate of up to 20% of the cases. Improved selection of the patients, progress in improving preoperatively the physical conditions of the patients, intra- and post-operative intensive care and improvement of the surgical technique have contributed considerably to reduce the risks of this procedure. Effective preparation of the small and large bowel, early anticoagulation and digitalis medication as well as an efficient antibiotic treatment starting intraoperatively, and optimal parenteral hyperalimentation are of particular importance. Adjuvant preoperative radiation therapy and a simultaneously performed pelvic lymph node dissection do not contribute to an increased morbidity or mortality rate. Taking into account all available preventive measures, the mortality rate of about 20% 20 years ago has been reduced to about 1-5% at present.

Follow-Up Studies↗
PubMed1980

Rapid radioimmunoassay for diagnosing acute tubular necrosis.

A previously described method for recovering a proximal renal tubular epitheal antigen (HRTE-1) from normal human kidney was modified by using ion-exchange and immunoaffinity chromatography in order to create easily reproducible conditions for antigen isolation. Radioiodinated HRTE-1 was then used to establish a 3-hour, double-antibody radioimmunoassay (RIA) for the purpose of testing whether the urinary excretion of this antigen might seve as a useful marker of acute tubular necrosis (ATN). Urines from 51 patients (ATN, 22: chronic nephropathies, 24; prerenal azotemia, 5) and from 36 normal subjects were assayed for HRTE-1. 79% of ATN patients had abnormal antigen concentrations while 100% of all other urines had urine antigen concentrations within a previously established range for random normal urine samples. When used as a differential diagnostic test of either ATN versus chronic nephropathies, or of ATN versus prerenal azotemia, 90 and 81% discrimination was achieved, respectively. The majority of ATN and prerenal azotemia patients presenting with atypical conventional diagnostic parameters (urine Na, urine osmolality, urine sediment, fractional Na excretion) were correctly diagnosed by RIA. Further study of HRTE-1 excretion in acute and chronic renal diseases seems indicated, both to elucidate pathophysiologic mechanisms and to determine whether HRTE-1 is a clinically useful marker of ATN.

Acute Kidney Injury↗
PubMedDate not supplied

Filter immunocytology: methodologic evaluation of a new assay for the diagnosis of urothelial cancer.

OBJECTIVE: Several investigators have demonstrated the high sensitivity of immunocytology in the diagnosis of transitional cell carcinoma (TCC). A new technique, designated "filter immunocytology" (FLIC), simplifies the technique of quantitative immunocytology, considerable decreases assay time and increases the percentage of assessable specimens. STUDY DESIGN: Voided urine samples were obtained from 89 patients without evidence of TCC and from 91 patients with histologically proven TCC. The cells were transferred onto a polycarbonate membrane. Immunostaining was performed using monoclonal antibody. Due ABC 3, directed against a differentiation antigen on urothelial cells. Specimens containing > 35% positive urothelial cells were regarded as abnormal. RESULTS: Of 153 specimens 180 (85%) were assessable. The investigation of 76 specimens from control patients and 77 from patients with TCC yielded a specificity of 86% and a sensitivity of 75%, respectively. Sensitivity did not correlate with tumor grade. Despite high interobserver and intrapatient variations regarding the amount of antigen-positive cells, a concordant attribution to either "normal" or "abnormal" was made in > 95% of cases. Intraobserver variation was small and did not influence the test result. CONCLUSION: These results suggest that FLIC assay may be a valuable adjunct to conventional cytology. A careful prospective investigation appears to be worthwhile to further define the indications for this technique.

Antibodies, Monoclonal↗
PubMedDate not supplied

Loss of function of the tissue specific transcription factor HNF1 alpha in renal cell carcinoma and clinical prognosis.

BACKGROUND: Human renal cell carcinogenesis is associated with loss of expression of tissue-specific genes and loss of function of tissue-specific transcription factors such as HNF(hepatic nuclear factor)1 alpha. MATERIALS AND METHODS: In this study HNF1 alpha DNA-binding activities and protein amounts were determined by gel retardation assay and Western blot analysis, respectively, in 42 non-metastasized renal cell carcinomas and paired normal tissues. RESULTS: 36 tumors out of 42 (86%) showed diminished binding activity of HNF1 alpha. In most cases (26 out of 42) this appeared to be due to decreased amounts of HNF1 alpha protein, but 10 tumors contained equal or even higher amounts of HNF1 alpha, in spite of reduced binding to DNA. Only 6 tumors out of 42 had unaltered HNF1 alpha binding activity. A clinical follow-up was obtained for 40 patients. Over an average follow-up period of 39 months no significant differences in the survival rate were observed between patients having lost or retained HNF1 alpha function. However, since most of the patients with retained function are still alive, long-term follow-up might be warranted. CONCLUSIONS: The very high incidence of loss of HNF1 alpha function indicates the important biological role of this change in renal cell carcinoma.

Adult↗
PubMedDate not supplied

Differential transfection efficiency rates of the GM-CSF gene into human renal cell carcinoma lines by lipofection.

One of the major questions in any gene therapy approach is the selection of the appropriate vector system. Here, the optimization of a gene transfer protocol for renal cell carcinoma using lipofection as a nonviral gene transduction system was evaluated. To select the promoter which gives the highest expression, different plasmids which are able to express Escherichia coli beta-galactosidase gene as a reporter gene under the control of different promoters were tested: human cytomegalovirus promoter (pCMVbeta), simian virus 40 promoter (pSVbeta), adenovirus promoter (ADbeta), and herpes simplex virus thymidine kinase promoter (TKbeta). The pCMVbeta revealed the highest expression of the beta-gal gene in the renal cell carcinoma (RCC) lines. Thus this CMV promoter was selected for the expression of the granulocyte-macrophage colony stimulator factor (GM-CSF) gene. Three different lipids (LipofectAmine, LipofectAce, and Lipofectin) were compared for their transduction efficiency, and the optimal conditions for quantitatively high lipofection rates were established. The consistently best results regarding gene expression as well as viability of the RCC lines were obtained when Lipofectin was used. Gene expression was monitored by a specific enzyme-linked immunosorbent assay and functionally validated by a cell proliferation test. The GM-CSF expression profile showed a peak at 48 hours after transfection and was still detectable after 5 days. Here the feasibility of efficient lipofection of the GM-CSF gene into RCC lines is demonstrated. Most importantly, considerable differences in the relative quantity of GM-CSF gene transfer into the different RCC lines was observed here. This may be of critical relevance for the design of any clinical gene transduction protocol in tumor cell vaccination attempts.

Carcinoma, Renal Cell↗