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Biomedical subjects

A van Dalen

Publications and source records attributed to A van Dalen.

At least 37 records · Page 2Linked to original sources
PubMed1997

Ultrasound guided synovial biopsy of the wrist.

Seven patients (4 female and 3 male, mean age 46) with arthritis of the wrist (n = 7) without known etiology were evaluated. High-definition ultrasound equipment was used for localization of synovial hypertrophy, suitable for ultrasound guided biopsy without risk. A 18-gauge diameter Tru-cut biopsy needle was used in an automated gun. Two passes were performed with continuous guidance of the needle-tip. In all patients representative synovial tissue was obtained in adequate amount. No complications were encountered. Ultrasound guided biopsy is proposed as an effective technique which can be performed with low patient discomfort on an outpatient basis.

Adult↗
PubMed1996

[Digital roentgen-guided large-needle biopsy as an alternative to surgical biopsy in patients with nonpalpable mammographic abnormalities].

OBJECTIVE: To compare histopathological findings from stereotaxic needle core biopsies and from excision biopsies performed on patients with impalpable breast lesions suggestive of carcinoma. DESIGN: Prospective and descriptive, with a description of the stereotaxic needle core biopsy procedure. SETTING: Academic Hospital Utrecht, the Netherlands. METHODS: In 36 patients core biopsies were done with 14-gauge biopsy needles, followed by a localisation procedure with surgical biopsy. The pathological features of the core and excision specimens were compared. RESULTS: Results of 35 (97%) core biopsies corresponded to those of excision biopsies. Stereotaxic core biopsy was not possible due to technical problems in 2 cases. CONCLUSION: Stereotaxic core biopsy appears to be an acceptable alternative to excision biopsy.

Adult↗
PubMed1996

[Favorable results of minimally invasive surgery in the treatment of primary hyperparathyroidism].

OBJECTIVE: To study the appropriateness of minimally invasive surgical treatment of primary hyperparathyroidism. DESIGN: Prospective. SETTING: University Hospital Utrecht, the Netherlands. METHOD: In patients with primary hyperparathyroidism, parathyroid adenomas were located preoperatively by means of Doppler assisted ultrasonography and spiral computer tomography. If the results were positive, minimally invasive surgery was performed. RESULTS: Minimally invasive surgery was carried out in 13 out of 15 successive patients with good results (the serum calcium and parathyroid hormone levels returned to normal). Two patients were subjected to conventional neck exploration, also with good results (preoperatively several adenomas were suspected in one, while no adenoma was seen in the other). CONCLUSION: It can be calculated that minimally invasive surgery will probably suffice in 60-70% of the patients with primary hyperparathyroidism, so that conventional neck exploration can be avoided.

Adenoma↗
PubMed1996

A multicentre evaluation of tumour marker determinations using the automatic Enzymun-Test Systems ES 300 and ES 600/700.

A multicentre evaluation of the determination of carcinoembryonic antigen (CEA), the cancer antigens CA 15-3, CA 19-9, CA 72-4 and CA 125 (II generation), the cytokeratin 19 marker Cyfra 21-1 and alpha-foetoprotein (AFP) using the Enzymun-Test System (ES 300 and ES 600/700) was performed in 23 laboratories. The tumour markers were measured in a total of 4266 human serum samples. The intra-assay precision was less than 5% in 80% of all serum samples investigated and in 95% of the serum samples at or above the cut-off level of the tumour markers. Inter-assay precision was less than 10% in 86% of the marker determinations. The interlaboratory survey also showed high reproducibility for the determination of all the tumour markers. In 3 laboratories the results of CA 15-3 in 283 serum samples were compared with the IRMA method of CIS bio international. The regression coefficient, r, was 0.967. In 4 laboratories the results of CEA in 312 samples were compared with the results obtained on the IMx analyser. The regression coefficient, r, was 0.967. In benign gynaecological diseases, CA 125 (II) was most frequently elevated in endometriosis. In gastrointestinal diseases it was proven that CEA is still the marker with the highest sensitivity as compared with CA 19-9 and CA 72-2 (59% with healthy controls as the reference group and 44% with patients having benign gastrointestinal disease as the control group). In pancreatic cancer CA 19-9 showed the highest sensitivity (78% and 62% respectively). In gastric cancer the three markers did not show statistically different results. When the gastric cancer patients were divided according to stage, CA 72-4 appeared to be more sensitive than CA 19-9 only in stage IV.

Antigens, Neoplasm↗
PubMed1995

Validation of the determination of amino acids in plasma by high-performance liquid chromatography using automated pre-column derivatization with o-phthaldialdehyde.

A sensitive and reproducible fully automated method for the determination of amino acids in plasma based on reversed-phase high-performance liquid chromatography and o-phthaldialdehyde pre-column derivatization is described. A 5-microns Spherisorb ODS 2 column (125 x 3 mm I.D.) was selected for routine determination. Over 40 physiological amino acids could be determined within 49 min (injection to injection) and 48 samples could be processed unattended. The coefficients of variation for most amino acids in plasma were below 4%. We were also able to measure trace amounts of amino acids in plasma normally not detected in a routine analysis. The results obtained with the method described compared favourably with those of conventional amino acid analysis (r = 0.997) and were in excellent agreement with those of other laboratories (r = 0.999).

Adult↗
PubMed1995

Analytical requirements and standardization of CA 15-3.

The CA 15-3 assay could play, probably in combination with cytokeratin markers, a role in the detection of early recurrence and in monitoring therapy in metastatic breast cancer patients. The CA 15-3 assay is, however, not useful for early detection of breast cancer and has no prognostic significance. The analyte is not clearly defined and a primary reference material cannot be synthesized. A reference measurement procedure is not available and many commercial assays use the original Centocor IRMA as such. The comparability of different CA 15-3 assays is not sufficient according to the results of EQAS. The general recommendations of analytical requirements for tumour marker determinations specified by the working group "Quality Control and Standardization" (Hamburger Symposia on Tumour Markers) includes intra-assay and inter-assay precision, drift, carry-over, dilution effect and high-dose hook effect. From a medical point of view reference limits should be established. Specificity/sensitivity profiles should preferentially be represented by ROCcurves. Confounding factors should be analyzed. To improve the clinical value of CA 15-3, the following needs for improvement have been identified: > Standardization of response criteria during treatment; > Definition of significant increase at recurrence; > Investigation of the biological variance during follow-up; > Definition of the analyte; > Preparation of reference material; > Development of an accepted reference method; > Integration of different international activities and > Optimizing decision-making criteria and clinical application.

Biomarkers, Tumor↗
PubMed1995

Electronic portal imaging.

In our institute, we have developed an electronic portal imaging system based on a matrix of 256 x 256 ionisation chambers. By improvements to the electronics, the system produces images with the same quality as the original system but 3-10 times faster. Software for automatic image analysis has been applied to more than 10,000 images over the last two years. Using an off-line correction strategy, the systematic patient set-up error has been limited to 5 mm or less for 98% of the patients treated for prostate cancer.

Equipment Design↗
PubMed1994

Monoclonal antibody M3 used in tissue polypeptide-specific antigen assay for the quantification of tissue polypeptide antigen recognizes keratin 18.

Recently, a new 'specific tissue polypeptide antigen (TPA)' test was introduced and designated tissue polypeptide-specific antigen (TPS); it is based on the monoclonal antibody (MAb) anti-TPS, M3. We have tested the specificity of this antibody by immunocyto- and immunohistochemistry, gel electrophoresis and immunoblotting. MAb M3 bound to intermediate filaments of epithelial cells and revealed a staining pattern identical to cytokeratin (CK) 18-specific MAb (DE-K18) on tissue sections of various human tissues. On immunoblots of proteins extracted from various epithelial cell lines, M3 reacted with a 45-kD protein corresponding to CK18, and on immunoblots of proteins isolated from MCF-7 culture fluid M3 stained three bands, 45, 33 and 29 kD. The same bands were stained with CK18-specific MAb, indicating that they represent CK18 and its degradation products. TPA, used as a tumor marker in clinical diagnoses and follow-up, was shown to be a degradation product of CK 8, 18 and 19. In contrast to TPA, MAb M3 did not stain CK8 and CK19 present on immunoblots.

Animals↗
PubMed1993

Gallstone size and the risk of gallbladder cancer.

The relation between gallstone size and gallbladder cancer was investigated in a matched hospital-based case-control study of surgical patients in a predominantly white population. Stone size was considered to be an indicator of the damaging effects of gallstones on gallbladder mucosa, which may enhance carcinogenesis. A radiologist determined the size of the largest gallstone within the gallbladder by reviewing hard copies of the ultrasonographic examinations of cases and controls. Between 1983 and 1989, 83 surgical patients with gallbladder cancer were identified in 18 participating hospitals. Hard copies were available for 72 patients and 208 matched controls. For 43 cancer patients and 98 matched controls stone size could be determined. In contrast to two other studies, no relation was found between stone size and gallbladder cancer. The reasons for this discrepancy are discussed.

Aged↗
PubMed1992

TPS in breast cancer--a comparative study with carcinoembryonic antigen and CA 15-3.

The serum levels of tissue polypeptide antigen were determined using the M3 monoclonal antibody (TPS) and compared with the serum levels of carcinoembryonic antigen (CEA) and breast carcinoma antigen 15-3 (CA 15-3) in 96 patients with benign breast tumors, in 25 breast cancer patients with no evidence of disease, in 139 preoperative breast cancer patients and in 298 samples of 25 breast cancer patients during therapy monitoring (4-22 samples per patient). The 95th percentile of TPS in 89 apparently healthy females was 51 U/l. The 95th percentile of TPS in patients with benign breast tumors was 55 U/l. The maximum TPS level in breast cancer patients with no evidence of disease was 56 U/l. In preoperative breast cancer the number of patients with TPS levels above the 95th percentile of TPS in benign breast tumors was significantly higher in stage III breast cancer as compared with stage I+II. This was not established for CEA and CA 15-3. During therapy monitoring TPS followed the course of the disease faster than CEA and CA 15-3 in patients with bone metastases, liver metastases, lung metastases and pleural effusion, with one exception. TPS levels could be correlated with progression of disease in patients with normal and steady levels of CEA and/or CA 15-3.

Antigens, Neoplasm↗
PubMed1990

Pre-operative tumour marker levels in patients with breast cancer and their prognosis.

The serum levels of carcino-embryonic antigen, tissue polypeptide antigen (TPA), breast carcinoma antigen 15-3 and mucin-like carcinoma-associated antigen were measured pre-operatively in 99 patients with breast cancer receiving no adjuvant hormonal or chemotherapy and in 64 patients with benign breast tumours. Using the 95th percentile of the marker levels in patients with benign breast tumours as the cut-off level, marker levels in patients with breast cancer were related to prognosis. In the follow-up period of 6-36 months (mean = 17.9 months), 20 out of the 99 patients developed metastases. Only 4 out of these 20 patients had elevated pre-operative levels of one or more of the markers. One out of these 4 patients was misclassified having metastatic disease at the time of the operation. On the other hand, in a total of 28 patients the pre-operative levels of one or more markers were noted to be elevated; 26 of the patients remained disease-free at the time of follow-up.

Antigens, Neoplasm↗
PubMed1989

Antibiotic sclerotherapy for renal cysts.

Seven patients with a large symptomatic renal cyst were treated by aspiration under US guidance and injection of a tetracycline solution (5-8 ml; 1%). All patients were relieved of complaints directly after treatment and US follow-up revealed complete remission or only small residual cysts after one week to twenty-one months. The combination of a strong sclerosing action with a long-acting local antibiotic prophylaxis gives tetracycline an advantage over other sclerosing agents, especially in patients with impaired renal function.

Aged↗