PubMed Health⌕ Search

Biomedical subjects

R Oyen

Publications and source records attributed to R Oyen.

At least 19 recordsLinked to original sources
PubMed1995

Extramedullary hematopoiesis encasing the pelvicalyceal system: CT findings.

A rare case of symmetric renal extramedullary hematopoiesis is hypothesized in a patient with long-standing Vaquez' disease and myelofibrosis. At CT, soft tissue densities were found in the renal hilar area encasing the pelvicalyceal system. Although there is nothing specific about the CT findings, the diagnosis can be suggested in the proper clinical setting. The association with generalized osteosclerosis is another diagnostic clue.

Diagnosis, Differential↗
PubMed1995

Selective protection against IgG binding to red cells treated with phthalocyanines and red light for virus inactivation.

BACKGROUND: Irradiation with red light of red cells (RBCs) containing the photodynamically active phthalocyanine (Pc) dyes is being studied for inactivation of lipid-enveloped viruses. One of the outstanding problems with this treatment is the binding of IgG to RBCs. The effects of oxygen and type I or type II quenchers on this IgG uptake were evaluated. STUDY DESIGN AND METHODS: The Pc compounds used were aluminum phthalocyanine tetrasulfonate (AIPcS4), HOSiPcOSi(CH3)2(CH2)3N(CH3)2 (Pc 4); HOSiPcOSi(CH3)2(CH2)3N+(CH3)3I- (Pc 5); and SiPcOSi[(CH3)2(CH2)3N+(CH3)3](2)2I- (Pc 6). RBCs were analyzed by flow cytometry for the presence of IgG. RESULTS: Irradiation with red light for 30 minutes of RBCs containing either 2 microM Pc 4, 2 microM Pc 5, 2 microM Pc 6, or 6.5 microM AIPcS4 resulted in an uptake of IgG. These conditions completely inactivated the lipid-enveloped vesicular stomatitis virus (VSV) (> 5 log10 kill). IgG uptake was reduced when oxygen was depleted. The addition of reduced glutathione (GSH) or mercaptoethanol prevented the binding of IgG with RBCs treated with AIPcS4, Pc 4, Pc 5, and Pc 6. Specific binding of IgG2 but not of C3d was observed upon irradiation of RBCs with Pc 5 and Pc 6 in the absence of GSH. No gross changes were observed in RBC antigen strength after irradiation with the dyes in the presence of GSH. Inactivation of VSV by Pc plus light was not affected by GSH. CONCLUSION: Sulfhydryl compounds are useful in preventing IgG binding to RBCs following Pc photosensitization. Since virus inactivation proceeds at the same rate in the presence and the absence of sulfhydryl compounds, their addition to treated RBCs should allow crossmatching for transfusion after treatment. The binding of IgG depends to a large extent on the generation of reactive oxygen species.

Antiviral Agents↗
PubMed1995

Neoadjuvant hormonal therapy before radical prostatectomy decreases the number of positive surgical margins in stage T2 prostate cancer: interim results of a prospective randomized trial. The Belgian Uro-Oncological Study Group.

PURPOSE: We investigated the effect of neoadjuvant treatment before radical prostatectomy for clinically localized prostate cancer. MATERIALS AND METHODS: A total of 130 patients with stages T2b and T3 prostate cancer was randomized in a multicenter study: 62 underwent immediate radical prostatectomy and 65 received 560 mg. estramustine phosphate daily for 6 weeks preoperatively. RESULTS: For clinical stage T2b tumors the neoadjuvant treatment resulted in a significant decrease in positive surgical margins compared to the nonpretreated group. This difference was not found for clinical stage T3 tumors. The impact on progression and survival still must be analyzed. CONCLUSIONS: Neoadjuvant treatment can be beneficial for clinical stage T2 prostate cancer. Optimal treatment for stage T3 tumors remains controversial.

Aged↗
PubMed1995

A novel common Kell antigen, TOU, and its spatial relationship to other Kell antigens.

A 47-year-old native American (TOU) was admitted to hospital for hip surgery. His serum agglutinated all red blood cells (RBCs) tested except Ko and DTT-treated RBCs and was weakly reactive with RBCs known to have a weak expression of Kell antigens, namely Kmod, McLeod, Kp(a+b-) (KEL:3,-4) and K:-13 (KEL:-13) phenotypes. RBCs from three siblings, a son and a daughter were incompatible with TOU's antibody. TOU's RBCs had the common Kell phenotype: K-k+Kp(a-b+c-)Ku+Js(a-b+)Ul(a-)K:11,-17K:14,-24K:12,13,18,19, 22,-23(KEL:-1,2,-3,4,5,-6,7,-10,11,12,13,14,-17,18,19,-21,22,-23,-24). Since TOU's RBCs were not agglutinated by an unidentified Kell-related antibody (IAN), tests were performed to show that TOU and IAN were mutually compatible. IAN is a Latino female hospitalised for a hysterectomy. The TOU antigen was shown to be located on the Kell glycoprotein by a monoclonal antibody immobilisation of erythrocyte antigen (MAIEA) assay. The unique pattern of reactivity obtained with TOU and IAN antibodies using this assay indicated the TOU epitope to be in an area remote from other Kell antigens, namely K, k, Kpa, Kpb, Kpc, Ku, Jsa, Jsb, U1a, K11, K12, K13, K14, Wka, K18, K19, K22 and K24 (KEL1, KEL2, KEL3, KEL4, KEL5, KEL6, KEL7, KEL11, KEL12, KEL13, KEL14, KEL17, KEL18, KEL4, KEL5, KEL6, KEL7, KEL11, KEL12, KEL13, KEL14, KEL17, KEL18, KEL19, KEL21, KEL22 and KEL24) but close to the low-incidence antigen K23 (KEL23).(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1995

K12 is located on the Kell blood group protein in proximity to K/k and Jsa/Jsb.

K12 is a high-prevalence antigen, with no known antithetical partner, that is associated with the Kell blood group system. We report studies on the 5th propositus (MS) with the K:-12 phenotype and the second case to show that the K12 is inherited. The anti-K12 in his serum did not destroy antigen-positive incompatible red cells transfused on at least 3 occasions over 6 years. Red cell membranes from MS possessed the Kell protein that was indistinguishable from control membranes. K12 antigen was shown by immunoprecipitation to be on a protein with an apparent molecular mass of 93,000 and by monoclonal antibody immobilization of erythrocyte antigens (MAIEA) assay to be on the Kell protein in proximity to K/k and Jsa/Jsb antigens. These data remove the K:-12 phenotype from its current Kell-related (or para Kell) status and elevates the K12 antigen to a bona fide member of the Kell blood group system.

Antibodies, Monoclonal↗
PubMed1995

Juxtaglomerular cell tumor: importance of clinical suspicion.

This case report of a reninoma or juxtaglomerular cell tumor illustrates that careful preoperative radiological investigation and preoperative frozen-section examination does not always lead to a correct diagnosis. The preoperative diagnosis of juxtaglomerular tumors should therefore primarily depend upon clinical suspicion, eventually followed by directed renal vein renin ratio blood sampling. The importance of early preoperative diagnosis and treatment is stressed.

Adenocarcinoma↗
PubMed1995

Case report: pseudotumoral pelvic retroperitoneal fibrosis associated with orbital fibrosis.

We report the case of a man with bilateral orbital fibrous pseudotumours and a large pelvic mass which was initially thought to be malignant. Sonographically guided transrectal core biopsies showed it to be a fibrotic retroperitoneal pseudotumour. The mass decreased after steroid therapy. The computed tomography and magnetic resonance imaging features of this unusual form of pelvic fibrosis as well as the association with heterotopic fibrosis are discussed.

Fibrosis↗
PubMed1995

Retroperitoneal schwannoma.

A case of an incidentally found retroperitoneal schwannoma is reported. A schwannoma is a rare, benign tumor affecting the soft tissues and the viscera. In the presented case, the US and CT images suggested the nature of this benign tumor. Angiography confirmed the mass effect on the portal vein and subsequently the potential risk of portal thrombosis. The diagnosis was confirmed at surgery.

Angiography↗
PubMed1995

[Spiral CT in parenchymatous disorders of the kidney].

Spiral-CT enables accurate diagnosis of renal parenchymal diseases and tumors, and when necessary, staging. Important prerequisites are optimal timing after injection of contrast medium and problem-tailored reformatting. In the optimal setting, this allows to reduce the examination time, the radiation dose, and the dose of contrast medium. Moreover, many other so-called complementary examinations as MRI, angiography, cavography, and diagnostic puncture can be avoided.

Adenocarcinoma↗
PubMed1994

Accuracy of combined computerized tomography and fine needle aspiration cytology in lymph node staging of localized prostatic carcinoma.

The sensitivity and accuracy rate of computerized tomography (CT) in lymph node staging of localized prostatic carcinoma is commonly considered to be low. Fine needle aspiration cytology of pathological lymph nodes seen on radiological staging can enhance this low accuracy rate. We prospectively investigated the accuracy of CT and fine needle aspiration cytology in lymph node evaluation of 285 patients with clinically locally confined prostatic carcinoma. The sensitivity, specificity and accuracy rates of this combined method were 77.8%, 100% and 96.5%, respectively. False-negative staging results were found in only 10 patients with minimal nodal disease. Although in contrast with previous reports, combined CT and fine needle aspiration cytology in our hands seems to be a highly efficient staging method for lymph node involvement. This method could be considered as an alternative to surgical lymphadenectomy in the preoperative evaluation of the nodal status of patients with localized prostatic carcinoma who are scheduled for radical prostatectomy or curative radiotherapy.

Aged↗
PubMed1994

Primary lymphoma of the uterine cervix.

A case of primary non-Hodgkin lymphoma of the uterine cervix is reported. The ultrasonographic and computed tomographic findings are described as well as the MRI appearance of this peculiar cervical mass. The best tumor delineation was achieved by T2-predominant and contrast-enhanced T1-weighted images. The lesion was treated successfully with external radiotherapy.

Adult↗
PubMed1994

[Hormone therapy before radical prostatectomy. Effects on surgical method and resection margins. Belgian Uro-Oncological Study Group (B.U.O.S.)].

127 patients with a clinical stage T2b and T3 prostate cancer were randomized in order to undergo either a radical prostatectomy alone or a radical prostatectomy after hormonal treatment (560 mg of estramustine phosphate daily for 6 weeks) in a prospective multi-center study. The clinical or radiological evaluation of an eventual downstaging being extremely difficult, the authors compared in the 2 groups the influence on the surgical act and the number of positive surgical margins at pathological examination of the resected specimen. There was no significant difference between the 2 groups concerning the surgery (duration of the procedure, blood transfusion, degree of difficulty). For clinical T2 prostate tumors the number of positive surgical margins was significantly lower in the group that had preoperative hormonal treatment. In the group with clinical T3 prostate cancer this difference was not found. The influence of positive margins on the later development of local or systemic recurrence and on survival still has to be awaited. At this moment one could conclude that only patients with a T2 prostate cancer benefit of a preoperative hormonal treatment.

Estramustine↗
PubMed1993

Tuberculosis of the adrenal glands: diagnosis by CT-guided fine needle biopsy.

Bilateral adrenal masses were found in a 64-year-old man with pulmonary tuberculosis and a pulmonary mass lesion suspicious for carcinoma. CT-guided fine needle biopsy of the left adrenal gland revealed tuberculosis. Adrenal metastases were thus excluded and probably Addison's disease, considered to be a potential complication of adrenal tuberculosis, could be prevented.

Adrenal Gland Diseases↗
PubMed1992

Temperature steering in prostate by simultaneous transurethral and transrectal hyperthermia.

Localized hyperthermia (HT) is presently under investigation as a treatment for benign prostatic hyperplasia and carcinoma of the prostate (CaP). One popular approach employs a transrectal (TR) device, a directional microwave (MW) applicator inserted into the rectum and aimed at the prostate. Alternatively, in the transurethral (TU) technique, a symmetrically radiating MW antenna is placed directly within the prostatic urethra. Used individually, TR applicators are capable of effectively heating (> 42 degrees C) the prostate up to 2 cm from the rectum, whereas TU applicators selectively heat the periurethral tissue with effective radial penetration of about 0.6 cm. Neither technique is of much value in heating the anterior prostate. In general, the highest temperatures are produced in the tissue immediately adjacent to the surface of intracavitary microwave devices. However, when MW antennas are used in arrays, the resulting heating pattern can differ significantly from that of the individual antennas. Heating at depth can be selectively enhanced and "steered" by adjusting the phase relationship between the devices. Prostatic temperature profiles were measured in 6 patients treated with TR alone, TU alone, and simultaneous TR and TU heating. In the combined treatments different phase relationships between the antennas were applied. We found that a higher temperature could be produced in the center of the prostate than on the surface of either applicator for certain phase relationships, and that the temperature profiles could be changed by shifting phase. The results of these measurements are in agreement with those of a computer simulation. Based on the above data we feel the combined use of TU and TR hyperthermia may be justified in Phase I-II trials for patients with locally advanced CaP.

Aged↗