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Biomedical subjects

O M Jensen

Publications and source records attributed to O M Jensen.

At least 19 recordsLinked to original sources
PubMed1998

Objective assessment of photoreceptor displacement and metamorphopsia: a study of macular holes.

BACKGROUND: We have developed a binocular perimetry technique for the quantitative assessment of retinal photoreceptor displacement and metamorphopsia. OBJECTIVE: To study the direction and amplitude of retinal photoreceptor displacement in eyes with idiopathic macular holes using our binocular perimetry technique. SUBJECTS: Five healthy control subjects and 10 patients with unilateral stage 3 to 4 macular holes in one eye and a healthy fellow eye. METHOD: Kinetic perimetry using red and green filter glasses, black binocular fixation targets, red and green selective monocular stimuli (Goldmann III-4-e), and fundus image superimposition of perimetry data. RESULTS: We found no discrepancy between the 2 visual fields in any healthy subjects. In patients with a unilateral macular hole, the central scotoma invariably extended beyond the rim of the hole. In 8 patients, each point on the rim of the scotoma had a perceptually corresponding location in the visual field of the fellow eye that was closer to the center of the visual field. In the 2 patients with the longest duration of symptoms (>2 years), no such discrepancy was found. CONCLUSIONS: Differential perimetry enables the objective study of retinal photoreceptor displacement and metamorphopsia. We found objective evidence for radial centrifugal photoreceptor displacement in most patients with idiopathic macular holes.

Aged↗
PubMed1998

Prognostic factors in soft tissue sarcomas: the Aarhus experience.

In the present study, the outcome, patterns of local recurrence and survival, as well as prognostic factors, were evaluated in patients surgically treated for soft tissue sarcomas. Between January 1979 and July 1993, 316 consecutive patients were referred to the Sarcoma Centre in Aarhus with localised malignant soft tissue sarcoma of the extremities or trunk. If possible, the patients were treated with a limb-sparing resection, primarily by use of a wide excision. 50 patients received adjuvant radiotherapy. There were 161 men (51%) and 155 women (49%) median age 56 years (range 1-94 years). 94 patients (30%) had tumours in the trunk, including shoulder and buttock lesions, 163 (52%) in the lower extremity and 59 (19%) in the upper extremity. 52 patients (16%) had grade 1 tumour, 60 (19%) grade 2 and 204 (65%) grades 3A-3B. The 5-year local recurrence rate was 18% and the 5-year survival rate was 75%. Multivariate analysis indicated the following variables as independent unfavourable factors for local recurrence: extracompartmental location, histological high grade, local excision, no adjuvant radiotherapy and intralesional/marginal excision. Independent unfavourable factors for survival were advanced age, extracompartmental location, histological high grade, lower extremity location and large tumour size. If the variable local recurrence was included in the analysis, it was found to have a very strong influence on survival. Based on these variables, a prognostic model was developed.

Adolescent↗
PubMed1998

Proliferative activity (MIB-1 index) is an independent prognostic parameter in patients with high-grade soft tissue sarcomas of subtypes other than malignant fibrous histiocytomas: a retrospective immunohistological study including 216 soft tissue sarcomas.

AIMS: To evaluate the prognostic value of tumour proliferative activity, p53 accumulation and bcl-2 expression in a retrospective series of 216 patients with soft tissue sarcomas (STS). METHODS AND RESULTS: The immunohistochemical analyses were performed on formalin-fixed, paraffin-embedded tissue. The proliferative activity was assessed by use of the monoclonal antibody MIB-1 and evaluated in multiple, random systematic sampled fields of vision. The percentage of proliferating cells (the MIB-1 index) ranged between 1% and 85% (median 12%). A significant increase in mean MIB-1 index was seen with increasing histological malignancy grade. Variation in the incidence of p53 accumulation and bcl-2 positivity among different histological subtypes was observed. p53 accumulation was frequent in synovial sarcomas and leiomyo- and rhabdomyosarcomas, whereas bcl-2 preferentially was expressed in synovial sarcomas. Univariate analysis identified patient age, tumour size, histological grade of malignancy, MIB-1 index and p53 accumulation as significant prognostic parameters. Multivariate Cox analysis, including tests for interaction terms between histological subtypes and MIB-1 index, showed independent prognostic effect of MIB-1 index and tumour size in patients with high-grade tumours of other subtypes than malignant fibrous histiocytoma (MFH). CONCLUSIONS: Histopathological malignancy grading is the most important single prognostic factor for overall survival in STS, but estimation of MIB-1 index is useful for identifying the least favourable subgroup of high grade STS of other subtypes than MFH, for whom adjuvant therapy may be indicated.

Adolescent↗
PubMed1996

The relationship between tumor oxygenation and cell proliferation in human soft tissue sarcomas.

PURPOSE: In malignant tumors the oxygenation status and tumor cell proliferation are known to influence local tumor control after radiotherapy. However, the relationship between oxygenation status and tumor cell kinetics in human tumors has not yet been described. Newly developed clinically applicable techniques such as oxygen electrode measurements and assessment of tumor cell proliferation rates have been suggested as promising predictive assays. The purpose of the present study was to characterize tumor oxygenation status in soft tissue sarcomas and to compare this with tumor cell kinetics and clinical parameters. METHODS AND MATERIALS: Pretreatment tumor oxygenation status was measured by polarographic oxygen needle electrodes and evaluated as the median pO2 and the percentage of pO2 values < or = 5 mmHg and < or = 2.5 mmHg in 22 patients with primary soft tissue sarcomas. All tumors were characterized by histology, grade of malignancy, the level of microscopic necrosis, the level of effective hemoglobin, and magnetic resonance imaging estimation of tumor volume. The tumor cell potential doubling time and labeling index were measured by flow cytometric and immunohistochemical analysis of tumor biopsy specimens after in vivo incorporation of iododeoxyuridine. RESULTS: There was a significant correlation between the median pO2 and the tumor cell potential doubling time (p = 0.041), whereas no correlation was found between the level of hypoxia expressed by the percentage of pO2 values < or = 2.5 and < or = 5 mmHg, respectively, and tumor cell potential doubling time. Furthermore, no correlation was found between either of the three tumor oxygenation parameters and labeling index. The material represented large intertumor heterogeneity in oxygenation status, cell kinetics, and tumor volume, and no correlation was found between oxygenation status and either volume, histopathology, grade of malignancy, or effective hemoglobin. CONCLUSION: This report is the first to suggest a correlation between tumor oxygenation and tumor cell doubling time, as the fastest proliferating tumor cells were found in the poorest oxygenated soft tissue sarcomas. More data are needed to clarify if this relation is really a true biological phenomenon. Furthermore, tumor oxygenation status of soft tissue sarcomas was heterogeneous and independent of clinical and histopathological parameters.

Adult↗
PubMed1996

[Can magnetic resonance imaging differentiate between benign and malignant conditions in patients with skeletal or soft tissue tumors?].

The records of 437 patients referred preoperatively for magnetic resonance imaging (MRI) due to clinical or radiological suspicion of a bone or soft-tissue malignancy were examined retrospectively in order to evaluate how good MRI is at distinguishing malignant from benign lesions. The MR-examination tends to overestimate malignancy. In all cases, the preoperative MR-examination correctly identified all malignant tumours as malignant, but also estimated a number of benign lesions as malignant. Sensitivity, specificity and predictive value was 100%, 71.2% and 76.4% respectively. In case of bursa/ganglion and pseudotumour, MR was able to correctly identify these lesions as benign. MR could not differentiate between the different types of sarcomas.

Diagnosis, Differential↗
PubMed1996

MIB-1 expression and iododeoxyuridine labelling in soft tissue sarcomas: an immunohistochemical study including correlations with p53, bcl-2 and histological characteristics.

We investigated the relationship between immunohistochemical estimates of proliferative activity and expression of bcl-2 protein and mutant p53 protein in 23 cases of soft tissue sarcoma. Furthermore, the reproducibility of estimates of proliferative activity was analysed and correlations between the variables and with mitotic score were investigated. Proliferative activity was assessed by use of monoclonal antibody MIB-1 and staining for iododeoxyuridine (IdUrd), and evaluated in multiple, random, systematically sampled fields of vision. MIB-1 indices were higher than those of IdUrd but for each case the two values were positively correlated (r = 0.78). The MIB-1 index correlated positively with mitotic score (2P < 0.001) and malignancy grade (2P = 0.001). The intraobserver reproducibility of the MIB-1 and IdUrd indices were excellent (r = 0.98 and r = 0.90, respectively). p53 expression was detected in 43% and strong bcl-2 expression was present in 57% of the studied cases. Expression of p53 and bcl-2 were not significantly correlated to proliferative activity or the histological features. We conclude, that the MIB-1 index is a reliable and reproducible estimate of proliferative activity and might improve the accuracy of conventional malignancy grading of soft tissue sarcomas. Furthermore, the results indicate that neither mutant p53 protein nor bcl-2 oncogene alone are sufficient to induce increased proliferation in these sarcomas.

Antigens, Nuclear↗
PubMed1996

Genital anomalies and risk for testicular cancer in Danish men.

In a cohort of Danish boys characterized by (1) being born between 1941 and 1957, (2) having attended schools in a defined area of Denmark, and (3) having a school health record available, 183 were registered in the Danish Cancer Registry with testicular cancer diagnosed before January 1, 1985. We selected 366 age- and sex-matched controls from the same cohort. Using information recorded by school physicians, we performed logistic regression analyses to estimate the relative risks (RR) associated with various genital anomalies. We found the risk for testicular cancer to be raised for men with a history of cryptorchidism [RR = 5.2; 95% confidence interval (CI) = 2.1-13.0], inguinal hernia (RR = 1.8; 95% CI = 0.9-3.7), hypospadias (RR = 4.2; 95% CI = 0.4-42.7), and hydrocele (RR = 2.4; 95% CI = 0.6-9.0). We observed no decrease in the risk associated with cryptorchidism after correction of the maldescent in early childhood. The RR of testicular cancer in the contralateral, normally descended testis in unilateral cryptorchid men was increased to 3.6. The results add to the growing evidence for a common causal factor for both testicular cancer and cryptorchidism and support the findings from other studies of associations between other genital anomalies involving the closure of the processus vaginalis and the risk of testicular cancer.

Adolescent↗
PubMed1996

Intradermal and subcutaneous leiomyosarcoma: a clinicopathological and immunohistochemical study of 41 cases.

Superficial leiomyosarcomas are rare tumours. The lesions confined to the dermis, contrary to those involving the subcutis, have been reported to carry a favourable prognosis. A retrospective study of 41 consecutive cases of surgically treated intradermal and subcutaneous leiomyosarcomas was undertaken in order to determine the prognostic factors that may influence the survival of these patients. Seven tumours were predominantly intradermal and 34 involved the subcutaneous tissue. Fifty-four percent of the tumours were located in the lower extremities. All cases stained positively for smooth muscle antigen and 66% for desmin. The tumours were classified with regard to tumour grade I (low grade, 3%), II (intermediate, 12%), IIIA (high grade, 46%) and IIIB (high grade, 39%). In all patients, follow-up information was available. Mean follow-up time was 5 years. The patients with intradermal tumours were all alive without signs of recurrence, whereas 14 of those with leiomyosarcomas involving the subcutis have died with pulmonary metastases. Our study confirms that "pure" intradermal leiomyosarcomas independent of tumour grade behave in a benign fashion, probably due to small tumour size. Tumour size > or = 5 cm, deep localization with fascia involvement, and high malignancy grade (IIIB) were found to deteriorate survival based on a univariate analysis. However, in a multivariate analysis only tumour size was found to be an independent prognostic factor.

Adult↗
PubMed1996

The bone-marrow infiltration pattern in B-cell chronic lymphocytic leukemia is not an important prognostic factor. Danish CLL Study Group.

In a multicentre study of 635 consecutive newly diagnosed patients with B-CLL, the histological bone marrow (BM) specimens were reviewed independently by each of 3 pathologists and found evaluable for BM infiltration pattern in 575 patients, 404 of whom had a CD5+, mainly FMC7-, faint surface-membrane immunoglobulin (SIg) fluorescence-intensity ppenotype. In these 404 patients the following BM infiltration patterns were found: mixed nodular-interstitial (30%), moderate interstitial (44%), heavy interstitial (20%) and diffuse packed (6%). In univariate survival analysis, significant differences were found according to BM pattern (p < 0.05), the presence of nodules being a favorable prognostic sign. In multivariate survival analysis in a model including age, clinical stage, BM pattern, BM lymphocytosis, WBC and sex, only age and stage but not BM pattern or BM lymphocytosis had independent prognostic significance. In stage A, progression-free survival was significantly longer in patients with nodular than in patients with non-nodular bone-marrow pattern. The overall survival of these patients, however, did not differ, possibly owing to the prompt and prolonged treatment given to most patients at the time of progression to stage B or C. We conclude that in CD5+, SIg(faint), mainly FMC7-B-CLL, bone-marrow histology may predict unstable disease in early clinical stage but is not important for treatment decisions, when these are based on clinical stage.

Age Factors↗
PubMed1995

Conjugation to preactivated proteins using divinylsulfone and iodoacetic acid.

Two methods for the preactivation of proteins and conjugation of peptides to proteins under mild conditions are presented. Preactivation of proteins with divinylsulfone (DVS) permits peptide conjugation through either amino, hydroxyl or sulphydryl groups depending on the coupling pH used, while preactivation with iodoacetic acid (IAA) N-hydroxy-succinimide ester permits selective conjugation through sulphydryl groups. In addition, the latter method allows quantitation of the conjugation ratio through determination of carboxymethyl cysteine after acid hydrolysis. The divinylsulfone activated proteins can be stored for extended periods of time at -20 degrees C until required for conjugation, while the iodoacetic acid activated protein can be stored for a few days at -20 degrees C. These conjugation methods were investigated with respect to obtaining peptide/protein conjugates for immunization purposes and for use as reagents in immunoassays. The DVS activated proteins permitted direct conjugation of luteinizing releasing hormone (LHRH) through its tyrosine side chain and allowed synthesis of well defined conjugates. The DVS derivatives of bovine serum albumin (BSA), reduced and carboxymethylated BSA and purified protein derivative (PPD) were compared with respect to their potential value as carriers for obtaining antibodies to LHRH (M(r) 1000) and epidermal growth factor (EGF, M(r) 5000). IAA-PPD was evaluated as a carrier for the conjugation of glutathione specifically through its cysteine side chain and for obtaining antibodies to glutathione. The antisera obtained were specific and of high titer, and the methods described here will thus allow the convenient synthesis of carrier conjugates with well defined characteristics.

Amines↗
PubMed1995

Penetrating keratoplasty and transscleral fixation of posterior chamber lens.

We reviewed the charts of 21 patients who underwent penetrating keratoplasty and transscleral fixation of a posterior chamber lens. One lens was sutured in an aphakic eye and 20 lenses were sutured after removal of an anterior chamber lens. Postoperative follow-up averaged 13 months (2-39 months). Visual acuity improved in 20 patients (95%) and remained the same in 1 patient (5%). Postoperative visual acuity was less than 0.1 in 5 patients (23.8%), 0.1 to 0.33 in 14 patients (66.7%) and better than 0.33 in 2 patients (9.5%). Twelve patients (57.1%) expressed a substantial reduction in ocular pain, 7 patients (33.3%) had no pain either before or after the operation, 2 patients (9.5%) expressed no reduction in pain. No cases of endophthalmitis, choroidal hemorrhage or retinal detachment were found. In one case, the sutured lens was dislocated without disturbing vision. Intraocular pressure increased in 3 of 9 patients with preoperative glaucoma. New-onset glaucoma developed in 1 patient. We find transscleral fixation of a posterior chamber lens to be an acceptable procedure in penetrating keratoplasty with IOL implantation where capsular support is inadequate for conventional implantation of a posterior chamber lens.

Adult↗
PubMed1994

Modulation and intracellular transport of CD20 and CD21 antigens induced by B1 and B2 monoclonal antibodies in RAJI and JOK-1 cells--an immunofluorescence and immunoelectron microscopy study.

By fluorescence microscopy (FM), flow cytometry (FCM) and immunoelectron microscopy (IEM) we have shown that B1 and B2 monoclonal antibodies (MoAbs) were able to induce modulation of CD20 and CD21 in RAJI and JOK-1 cell lines. Redistribution and internalization of both antigens (Ags) after binding with MoAbs was readily demonstrated by FM, and by IEM CD20 and CD21 were found to be processed by the pathway of receptor-mediated endocytosis. The rate of intracellular transport varied: CD21 > CD20 and RAJI > JOK-1. Approximately 65 and 55% of CD20 and 60 and 45% of CD21 were cleared from the surface of RAJI and JOK-1 cells, respectively (FCM and IEM). These values, however, clearly exceeded those corresponding to internalization (11, 9, 24 and 16%) indicating shedding of Ag-MoAb complexes. No evidence of recycling was found. The present data support the hypothesis that the kinetics of modulation vary from one Ag to another and probably also reflect the stage of differentiation of the malignant B-cells. The results are discussed in the context of the possible usefulness of B1 and B2 MoAbs in the therapy of B-cell malignancies.

Antibodies, Monoclonal↗
PubMed1994

Changing indications for penetrating keratoplasty.

The indications for penetrating keratoplasty have changed over the past several years. One hundred and eighty cases of penetrating keratoplasty performed in the Department of Ophthalmology, Naestved Centralsygehus, Denmark, from January 1984 to December 1993, were analysed. Overall pseudophakic bullous keratopathy was the most common indication for penetrating keratoplasty (28.3%). This was followed by keratitis (13.9%), Fuchs' dystrophy (13.9%), regraft (11.1%), aphakic bullous keratopathy (10.0%) and keratoconus (6.7%). Pseudophakic bullous keratopathy was the most common indication for penetrating keratoplasty in 1989 and in each year from 1991 to 1993. Before 1989 the most common indications were keratitis (18.0%) and aphakic bullous keratopathy (14.8%). The emergence of pseudophakic bullous keratopathy, as the most common indication for penetrating keratoplasty, correlates well with the dramatic increase in the number of cataract extractions with intraocular lens implantation performed since the early 1980s. Especially semiflexible, closed-loop anterior chamber lenses used in our department in the early years of the period, have been the cause of subsequent corneal edema.

Adolescent↗
PubMed1994

Quantitation of immunogold with an interactive image analysis system. A new, practical approach to antibody-induced modulation, internalization and intracellular transport of surface antigens in viable hematopoietic cells.

This work aimed to evaluate the value of computerized quantitative analysis in ultrastructural studies on internalization and intracellular transport of leukocyte antigens traced with immunogold in viable lymphoid cells. The time of analysis and the results were compared with those obtained with a standard method based on counting gold particles on electron micrographs. A commercially available, personal computer-based, single-screen system was used for capturing and processing the ultrastructural images, counting gold particles and presenting data. The viable lymphoblasts of RAJI and NALM-6 cell lines were labeled with B4 (anti-CD19) murine monoclonal antibody followed by rabbit antimouse immunoglobulins coupled to 12.8-nm colloidal gold, cultured for six hours to allow internalization of CD19 antigen, collected after various periods of time and processed for electron microscopy. Each sample was analyzed by counting the gold particles on 30 randomly chosen, equatorial cell sections. Surface-bound particles and those located within certain intracellular compartments (that is, cytoplasmic vesicles, multivesicular bodies and lysosomes) were counted separately. No significant differences were found between the results obtained using electron micrographs and those yielded by on-screen analysis of digitized images. However, the time of analysis varied considerably--approximately eight and two hours, respectively. Also, using computerized analysis saved the cost of photographic processing. In conclusion, the system provided a reliable, rapid and inexpensive alternative for quantitation of immunogold-labeled leukocyte antigens at the ultrastructural level.

Antibodies↗
PubMed1993

Antibody-induced modulation and intracellular transport of CD10 and CD19 antigens in human B-cell lines: an immunofluorescence and immunoelectron microscopy study.

Antibody-induced antigenic modulation (AIAM) of CD10 and CD19 was studied on NALM-6, RAJI, and JOK-1 cell lines using fluorescence microscopy (FM), flow cytometry (FCM), and immunoelectron microscopy (IEM). Cross-linking with monoclonal antibodies (MoAbs) induced rapid redistribution of CD10 and CD19 on the cell surface (FM) followed by internalization involving uptake through plasmalemmal pits, transfer through endosomal compartment (receptor-mediated endocytosis), and, finally, delivery to lysosomes for degradation or exocytosis and recycling (IEM). Significant quantitative differences regarding modulation and intracellular processing were shown by FCM and IEM. Thus, 35%, 30%, and 25% of CD10 compared with 80%, 60%, and 40% of CD19 were internalized in NALM-6, RAJI, and JOK-1 cells, respectively. Also, the rate of intracellular transfer as well as externalization and recycling was more pronounced in the case of CD19 than of CD10 and in the NALM-6 and RAJI cells compared with the JOK-1 cells. These differences may possibly reflect the functional significance of CD10 and CD19 as well as the stage of differentiation of the malignant B cells. Although both antigens can be useful in MoAb-targeted immunotherapy, our findings suggest that anti-CD19 MoAbs would be preferable for delivery of cytotoxic agents to malignant B cells.

Animals↗
PubMed1993

Case-control study of risk factors for cervical squamous-cell neoplasia in Denmark. III. Role of oral contraceptive use.

The role of oral contraceptive (OC) use in relation to the risk of cervical neoplasia (squamous cell) was investigated in a population-based case-control study in Denmark of 586 women with histologically verified cervical carcinoma in situ (CIS), 59 women with invasive cervical cancer from Copenhagen, and 614 controls drawn at random from the female population in the study area. Ever use of OCs was associated with an increased crude risk for carcinoma in situ (relative risk [RR] = 1.8, 95 percent confidence interval [CI] = 1.3-2.5). The crude risk in relation to invasive carcinoma was 1.6 (CI = 0.7-3.5). After adjustment for potential confounders (excluding human papillomavirus), the risks were marginally increased, but not statistically significant (CIS: RR = 1.4, CI = 0.9-21: invasive: RR = 1.3, CI = 0.5-3.3). The risk increased with duration of use; compared with never users, the adjusted RR for carcinoma in situ was 1.9 (CI = 1.1-3.1) for women who had used OCs for six to nine years, and 1.7 (CI = 1.0-2.7) for women who used OCs for 10 years or more. This was independent of years since last use since both recent and non-recent long-term users were at an increased risk. This trend in risk with duration did not apply to the same extent to invasive lesions. The observation that the risks related to OC use were found both in women who had ever had a Pap smear and in women who had never been screened previously may speak against detection bias as an important factor.

Adult↗