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Biomedical subjects

W Meier

Publications and source records attributed to W Meier.

213 records · Page 12Linked to original sources

MRI of pelvic masses: efficacy of the rectal superparamagnetic contrast agent Ferumoxsil.

The purpose of this study was to determine the potential value of rectally administered Ferumoxsil for pelvic MRI. Twenty patients with suspected rectosigmoid and ovarian tumors were prospectively examined before and after rectal administration of 300 to 600 ml of the superparamagnetic contrast agent Ferumoxsil. Imaging parameters (1.5-T system, phased-array coil, transverse T1-weighted spin echo (SE) and T2-weighted turbo-SE sequences, 6-mm slice thickness, 350-mm field of view [FOV], 512 x 512 matrix) were kept constant. Images were evaluated for tumor presence, lymphadenopathy, bowel involvement, and peritoneal implants. Precontrast and postcontrast studies were rated for bowel delineation, lesion/organ-to-bowel differentiation, presence of artifacts, and confidence of diagnosis. Delineation of rectum and sigmoid colon (P < .001) as well as separation of bowel and vagina, uterus/adnexa, dome of the urinary bladder, lymph nodes, and vessels improved significantly (P < .01) on both T1-weighted and T2-weighted postcontrast sequences. The rectal contrast agent did not increase the level of artifacts. Changes in diagnosis in 7 of 20 patients were mainly due to identification of colorectal tumors or bowel involvement on postcontrast images. The readers' diagnostic confidence was significantly higher on contrast-enhanced than on unenhanced studies (93 +/- 6.4% vs 68 +/- 25.2%). Rectal application of Ferumoxsil improves lesion/organ-to-bowel delineation and overall diagnostic confidence in pelvic MRI.

Administration, Rectal↗

Haematopoietic transplant potential of unrelated and related cord blood: the first six years of the EUROCORD/NETCORD Bank Germany.

To date, human umbilical cord blood (CB) has been employed successfully in well over 1000 allogeneic (unrelated and sibling) stem cell transplantations. Because of primary limitations in volume and cell numbers, over 90% of these transplantations were performed in children. Therefore requests for well standardised cord blood units of high quality are now increasing constantly. Examination and standardisation of unrelated and related cord blood stem cell preparations and banking as well as their biological characterisation was already initiated in Düsseldorf in 1992. Hitherto a total of 3236 CB samples with a mean volume of 89 +/- 25 ml, a mean total number of nucleated cells (NC) of 10 +/- 5 x 10(8) and a mean number of CFU-GM of 6 +/- 5 x 10(5) have also been validated by haematological, immunological and microbiological criteria. In addition to that, 97 directed CB donations of siblings with a clinical indication have been characterised and banked along the same lines. All CB units were collected from the umbilical cord vein immediately after vaginal full term delivery or caesarean section, then frozen and stored in liquid nitrogen. 1940 CB units were stored unseparated, the other 1296 were volume reduced using Hetastarch (HES) with a mean recovery of 85 +/- 13% of the nucleated cells, 86 +/- 12% and 84 +/- 13% for CFC and CD34+ cells, respectively. Only 5.0 ml of a CB sample is required for routine laboratory testing as there are HLA-class I typing, HLA-class II typing by sequence specific oligonucleotide probes (PCR-SOP), ABO typing, sterility control, assessment of progenitor and stem cells by colony forming assays, and CD34+ status as well as certain viral infections such as CMV, Hepatitis B, C, HIV, Parvo B19 by PCR technology before releasing the CB unit for transplantation. For apparent viral infections, maternal sera obtained at birth were tested for HBsAg, anti-HBc, anti-HCV, -HAV-(IgG, IgM), -HIV-1-2, -EBV- (IgG, IgM), -HTLVI-II, -CMV (IgM, IgG), toxoplasmosis and syphilis. Within the last three years a total of 4860 preliminary searches and 680 extended unit reports were submitted to the CB bank Düsseldorf by fax or World Wide Web. So far 68 unrelated and 3 related CB units were delivered. From these 70 have been transplanted in 30 different transplant centres world-wide. Until now the evaluation of the first 53 unrelated CB-transplantations was performed together with the EUROCORD transplant registry. Three patients were excluded from the analysis, since they received an unrelated CB-transplant for non-engraftment after previous allotransplants. The median patient age of these 50 patients was 5.0 years (range 0.3-44), the median weight 18 kg (range 4-70 kg). The majority of the patients transplanted for malignancies (66%) suffered from ALL (n = 19), AML (n = 7), CML (n = 4) and lymphoma (n = 2) with two third (75%) in an intermediate (2nd CR) or advanced stage of disease (> 2nd CR); 13 patients had metabolic diseases and immunodeficiencies and three had aplastic anaemia. All CB samples as well as the patients' blood samples were typed in Düsseldorf for HLA-class I by serology confirmed by PCR-SSP and by high resolution DNA typing for HLA-DRB1 and HLA-DQB1 alleles. 96% of the 50 patients receiving unrelated CB were mismatched at one or more HLA-antigens. 41 of the 50 patients transplanted with unrelated CB from Düsseldorf were evaluable for engraftment with an overall engraftment rate of 83%. According to the defined criteria of EUROCORD, 9 of the 50 patients were not evaluable for engraftment, since they died before day 60. The present median follow-up time is 14 months (1.4-38). The Kaplan-Meier estimate of survival at one year is 42 percent. The three paediatric patients after sibling CB transplantations (ALL, amegakaryocytic thrombocytopenia and CML) are alive with a follow-up time of 350, 379 days and 531 days. (ABSTRACT TRUNCATED)

Adolescent↗

Improving first-line therapy of advanced ovarian cancer - the AGO Ovarian Cancer Study Group perspective.

This review displays the AGO Ovarian Cancer Study Group approach towards evaluation of improvement options in first-line therapy of advanced ovarian cancer. Prospectively randomized phase III trials evaluating the addition of newer drugs to standards carboplatin-paclitaxol (TC) as well as pilot trials evaluating new treatment modalities like anti-idiotype CA 125 antibodies or epidermal growth factor receptor (EGFR) modulation are presented.

Antineoplastic Combined Chemotherapy Protocols↗

Ovarian cancer--can intraperitoneal therapy be regarded as new standard in Germany?

The German Arbeitsgemeinschaft Gynaekologische Onkologie (AGO) and the two German cooperative study groups (AGO-OVAR and NOGGO) performed a review of the currently available literature on intraperitoneal first-line treatment in advanced ovarian cancer to consider if this new option should be incorporated into the German guidelines for treatment of ovarian cancer.

Antineoplastic Agents↗

Noninavasive angiography for the diagnosis of carotid artery disease using Doppler ultrasound (carotid artery Doppler).

To detect stenosis in the carotid artery with a bidirectional continuous-wave Doppler ultrasound device, the following noninvasive procedure, applied on 800 patients and compared with 249 angiograms of 186 patients, has proved to be about 90% reliable. Measurements of flow signals were taken over the terminal branches of the ophthalmic artery (supratrochlear and supraorbital arteries) and averaged. Compression of superficial temporal and facial arteries revealed flow direction and common carotid artery compression revealed the supplying blood vessel and the effectiveness of the circle of Willis. Measurements over the common carotid arteries were used to evaluate peripheral resistance. A set of eight criteria was used; the diagnostic value of each criterion was calculated by comparing 138 pathological Doppler findings in 123 patients with the angiograms. If reverse flow direction in supratrochlear or supraorbital artery was used alone, only 43% correct diagnoses would have resulted. A more severe stenosis is not necessarily correlated with a more weighted criterion; a subset of criteria is less efficient than the combination of all criteria. Application during 32 extracranial endarterectomies on 28 patients informed the surgeon immediately about the hemodynamic effect of the surgical intervention. Rethrombosis was diagnosed in two patients by postoperative Doppler examination.

Carotid Artery Diseases↗

Comparison of CYFRA 21-1, TPA and TPS in lung cancer, urinary bladder cancer and benign diseases.

Recently CYFRA 21-1, a new tumor marker measuring a fragment of cytokeratin 19, was introduced and proved to be suitable for therapy monitoring and follow-up of non-small cell lung carcinomas (NSCLC), in particular squamous cell carcinomas. Besides CYFRA 21-1 there are two other tumor markers, tissue polypeptide antigen (TPA) and tissue polypeptide-specific antigen (TPS), which also measure various cytokeratins in serum. In a retrospective study we investigated the clinical significance of these three cytokeratin markers in lung cancer and in carcinoma of the urinary bladder. For this purpose we investigated the sera of 50 healthy persons, 273 patients with various benign diseases, 218 patients with histologically proven lung cancer and 88 patients with carcinoma of the urinary bladder. In a first step the specificity was established for the different reference groups and the cutoff values were fixed at a specificity of 95%. In lung cancer the single and combined sensitivities were calculated versus benign lung diseases (n = 58) as reference group. With single determinations CYFRA 21-1 proved to have the highest sensitivity in lung cancer in general (61%), in non-small cell lung carcinomas (64%), in squamous cell carcinomas (79%), in adenocarcinomas (54%) and in large cell carcinomas (65%). In small cell lung carcinomas (SCLC) NSE was confirmed to be the marker of choice (55%). With combined determinations a clear increase in sensitivity could only be reached in large cell carcinomas (CYFRA 21-1 + TPA: 77%) and in small cell carcinomas (CYFRA 21-1 + NSE: 62%).(ABSTRACT TRUNCATED AT 250 WORDS)

Automation↗

[Three-dimensional visualization of stationary flow behind artificial heart valves].

The visualization and quantitative analysis of flow offers a possibility for the hydrodynamic characterization of artificial heart valves. Different types of valves can be compared if velocity profile and the turbulent shear stress caused by the prosthesis are known. The tracer technique was selected, since it permits visualization also of turbulent flow through the valve. With the aid of a simple optical device the three-dimensional flow pattern behind the valve is determinable. The main features of the method are: The regions of interest can easily be identified. Velocity profiles can be determined and shear stress and turbulence intensities estimated. The experimental setup is simple, calibration is not necessary, and it can be used for turbulent flows. The method can be used only with transparent fluids and vessels; measurements in blood are not possible. Because of the large number of measuring points required the method is very time-consuming. The use of an automatic picture analyzing system would make it possible to increase the number of pictures processed, and thus increase resolution. The velocity profile of a three-finger-valve, the TAD 29, was established at a distance of 20 mm from the ring, and compared with known profiles from the literature. The valve has an opening angle of 70 degrees. All typical regions for the flow of an artificial heart valve, such as jet, stagnation gone, backflow and turbulence were demonstrated.

Blood Flow Velocity↗

Significance of the tumour markers CA 125 II, CA 72-4, CASA and CYFRA 21-1 in ovarian carcinoma.

We compared the tumour marker CA 72-4 and the new markers CASA and CYFRA 21-1 with the established marker CA 125II in follow-up care and control of efficacy of treatment in ovarian cancer in order to determine whether there are differences in recognizing ovarian carcinomas of different histological type. The investigation was done retrospectively on serum samples frozen at -80 degrees C obtained from 262 subjects, among them 50 healthy women, 53 sera with benign gynecological diseases and 159 sera with ovarian cancer, 72 of them at the time of primary diagnosis. We used commercially available kits: CA 125 II: Centocor RIA, CASA: Medac EIA, CA 72-4: Centocor RIA and CYFRA 21-1: Boehringer EnzymunR ELISA. Fixing specificity at 95% versus benign gynecological diseases as a clinically relevant reference group, we found cut-off values of 160 U/mL for CA 125II, 6.5 U/mL for CASA, 6.8 U/mL for CA 72-4 and 2.4 ng/ml for CYFRA 21-1. Based on this specificity we can compare the corresponding sensitivities at the time of primary diagnosis (n = 72): CA 125 II 47%, CA 72-4 47%; CASA 31% and CYFRA 21-1 44%. Regarding histological types of ovarian carcinomas, we found a sensitivity of 50% for CA 125 II and CASA, 36% for CA 72-4 and 33% for CYFRA 21-1 in serous ovarian cancer (n = 53), 21% for CA 125 II and CASA, 36% for CYFRA 21-1 and 43% for CA 72-4 for mucinous ovarian cancer (n = 27). Serous ovarian carcinomas were classified by higher FIGO-stages than mucinous ovarian carcinomas. Additional sensitivities were found at the time of primary diagnosis for the combination of CA 125 II and CA 72-4 and in serous ovarian cancer for CA 125 II and CASA. According to our results, at the time of primary diagnosis the combined determination of CA 125 II and CA 72-4 is useful. If both are negative, determination of CASA can be helpful. For follow-up care and control of efficacy of treatment the preoperative positive or leading marker is sufficient.

Adenocarcinoma, Mucinous↗

Prognostic significance of CA125 in patients with ovarian cancer and secondary debulking surgery.

Prognostic outcome of patients with bulky disease after primary surgery in ovarian cancer remains extremely poor. One possible approach to achieve prolonged survival is secondary debulking surgery, but only in those patients without residual tumor after the second surgery. In 79 patients with secondary debulking surgery preoperative CA125 values were determined. In 52% of the patients with CA125 values below 35 U/ml a tumor free situation could be achieved at secondary debulking. In contrast, the percentage of patients macroscopically free of disease with levels above 35 U/ml was only 22%. Furthermore, there was a significant difference in survival time depending on CA125 values at the time of secondary debulking. Patients with levels below 35 U/ml survived 49 months, women with values above 35 U/ml survived only 30 months respectively. In conclusion, CA125 is an important prognostic tool for predicting a tumor free situation at secondary debulking surgery. In patients with values above 35 U/ml secondary debulking should be indicated restrictively, even if other preoperative diagnostic tools would predict a tumor free situation after secondary cytoreductive surgery.

CA-125 Antigen↗

Significance of tumor marker determinations in the primary therapy of ovarian cancer.

In 296 patients with primary ovarian cancer the sensitivity and specificity of CA125 and carcinoembryonic antigen (CEA) were determined. High CA125 values can be found in serous cystadenocarcinomas, CA125 can also be detected in patients with mucinous carcinomas. Only in cases negative for CA125 should other tumor markers be determined. As a second choice CA72-4 is proposed, since because of its low sensitivity of only 9% CEA should no longer be regularly determined in ovarian cancer. Preoperatively determined CA125 values show no prognostic significance in primary ovarian cancer. The means of CA125 half life in primary therapy demonstrated prognostic significance, and therefore patients with a worse prognostic outcome can be spared the adverse side effects of ineffective chemotherapy.

Biomarkers, Tumor↗

Prognostic significance of squamous cell carcinoma (SCC) antigen in primary advanced and recurrent cervical carcinoma.

Between January 1986 and June 1992 56 patients with cervical carcinoma were treated with cytostatic drugs in our department. In all patients showing primary response to therapy, the SCC and CEA levels fell rapidly to normal after one or two cycles. In contrast, clinical remission was not obtained in those patients with levels which remained high or rose again following an initial decrease. Using tumor markers, treatment can be individualized so that, cases of therapy failure or further tumor progression can be detected early and the patient can be spared the severe side effects of treatment.

Antigens, Neoplasm↗

CA125 based diagnosis and therapy in recurrent ovarian cancer.

Approximately 85% of patients with advanced ovarian cancer will experience recurrence of the disease. In 311 patients CA125 serum levels were determined at follow up investigation in our department. A sensitivity of 92% and specificity of 89% were calculated. Reflecting the further course of disease, specificity could be increased up to 97%. Using 25 U/ml/month as the upper limit of grade of CA125 increase, a 100% specificity for detecting recurrence could be achieved. In conclusion, recurrence diagnosis and even therapy should be started in cases of either significantly raised CA125 levels or elevated grade of CA125 increase.

CA-125 Antigen↗

Value of HAMA--determination in clinical practice--an overview.

HAMAs (human anti mouse antibodies) in serum of patients may be stimulated as an immunologic reaction to the application of animal protein. They are differentiated into heterophilic (species-unspecific) and mouse-specific anti-isotypic (often IgG1) or-idiotypic antibodies as well as according to the human immunoglobulin type (IgG or IgM). Besides infrequent clinically immunologic side effects (anaphylactic reaction), their influence on tumor marker measurements predominates in the follow-up of tumor patients by the possible impairment of newly applied monoclonal antibodies. The detection of HAMAs is performed on suspicion of a tumor by self-made or commercial tests, however, there is no consensus standardization of tests, standards and controls. Experiences are reported herein on the occurrence of heterophilic antibodies, reasons of suspicion, detection and removal, comparative determination of HAMAs by two commercially available tests (ImmunoSTRIP HAMA, Enzygnost) and HAMA induction in patients following immunoscintigraphy (OC-125, n = 27). Besides the rare appearance of HAMAs in patients without pretreatment or following biologic therapy, i.v. application of monoclonal antibodies for diagnosis (immunoscintigraphy) or therapy represents the most frequent reason for HAMA development that should always be ruled out in case of anamnestic indication and clinically unexplained tumor marker changes.

Animals↗