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Biomedical subjects

N Bornfeld

Publications and source records attributed to N Bornfeld.

135 records · Page 8Linked to original sources

Development and ultrastructure of peripheral subretinal neovascularizations.

Anterior to the equator an additional vascular layer can regularly be found between peripheral retina and choroid. The vessels are located within Bruch's membrane, subjacent to the retinal pigment epithelium. Apparently, this layer is not present at birth and develops at a relatively young age. With the electron microscope all steps of vasculogenesis could be followed. The presence of such vessels also in the eye of a 29-year-old individual suggests that they represent a physiologic condition rather than an ageing change. In contrast to the subretinal neovascular membranes of the posterior fundus, these peripheral neovascularizations show no relation to any known fundus disease.

Adult↗

The architecture of the most peripheral retinal vessels.

The vascular bed of the extreme periphery of the human retina is characterized by the occurrence of relatively wide arcades and bridging vessels connecting the peripheral portions of arteries and veins. These vessels differ from the more posterior capillaries not only by their larger diameter but also by the presence of a perivascular halo, which consists of an electron-translucent ground substance containing fine collagen fibrils, basement membrane material, dense bodies, vesicles, and portions of macrophages. The appearance of the external portion of the halo and the relationship of its collagen fibrils to the basement membrane of the surrounding Müller cells is indistinguishable from that of the cortical vitreous and the inner limiting membrane located at the vitreoretinal interface. Toward the periphery the thickness of the halo increases from vessel to vessel. As a rule, one or more of the vessel loops closet to the ora serrata are occluded. The structure of these occluded vessels is identical with the structure of the halo.

Animals↗

Whole-body fluorine-18 fluordeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in staging of advanced uveal melanoma.

Fluorine-18 fluordeoxyglucose positron emission tomography (FDG-PET) is an useful tool in diagnosing and monitoring of malignant cutaneous melanoma. However, the feasibility and usefulness of FDG-PET in uveal melanoma is not yet established. We present a patient with suspected advanced uveal melanoma who underwent combined FDG-PET/computed tomography (CT) for staging. FDG-PET/CT images demonstrated vital intraocular tumor. Anatomical assignment of the malignancy to the choroid was possible by means of the coregistered computed tomography. Furthermore, PET revealed an unknown otherwise undetected vital liver metastasis. We conclude that combined FDG-PET/CT has potential to further improve staging and therapy planning in patients with advanced uveal melanoma.

Aged↗

Preliminary results of primary chemotherapy in retinoblastoma.

BACKGROUND: Eye retention rates after external beam therapy for advanced retinoblastoma are close to 90% with very few ocular side effects like radiation retinopathy or radiation induced optic neuropathy. Late complications, however, comprise a sixfold increase of secondary non-ocular cancers like soft tissue sarcomas demanding alternative treatment options in the management of advanced retinoblastoma. PURPOSE: A phase I study on primary chemotherapy using vincristine, cyclophosphamide, etoposide and carboplatin in advanced bilateral retinoblastoma was undertaken to evaluate the potential of a treatment regimen not including external beam therapy. PATIENTS AND METHODS: 12 eyes with 17 tumors in 9 children were treated with primary chemotherapy as first treatment option with a mean follow-up of 16.7 months. Planned enucleation of a tumor containing eye was performed in 2 eyes. In one of these enucleated eyes no viable tumor cells were visible on histopathological examination while in the other eye marked tumor regression was detectable. Of the remaining 10 eyes clinical regression of the intraocular tumors was present in all eyes; on average the tumor size was reduced by 50% within 3-6 weeks. Most of the tumors showed a type I (cottage cheese) regression indistinguishable from regression patterns found after external beam radiotherapy. Ancillary treatments including laser photocoagulation, beta-ray brachytherapy, external beam radiotherapy and cryotherapy were performed in 15 out of the 17 tumors. CONCLUSION: Based on the results of this study and on the results published by others primary chemotherapy may result in the same eye retention rate as conventional external beam therapy avoiding the unacceptable high rate of secondary non-ocular cancers in the latter. A prospective study to be undertaken by the GPOH (Gesellschaft für Pädiatrische Onkologie und Hämatologie) and the RG (Retinologische Gesellschaft) is planned to further evaluate this new and promising approach.

Antineoplastic Combined Chemotherapy Protocols↗

[Retinopathy of prematurity: an analysis of risk factors].

In 29 infants with retinopathy of prematurity we retrospectively studied the influence of various clinical factors on the severity of the disease and compared this group of patients with controls without retinopathy. Infants presenting with different stages of retinopathy showed significant differences in gestational age, length of mechanical ventilation, additional supplemental oxygen, and the number of episodes of acidosis and hypocarbia. Compared with controls, hyperoxemia with paO2-levels above 100 mmHg and hypocarbia with pCO2-levels below 35 mmHg was more often observed in infants with retinopathy (p < 0.05, respectively p < 0.01). Besides, these infants were more often treated with surgical ligation of a patent ductus arteriosus than with indomethacin (p < 0.001). In our patients we were not able to assess the incidence and the severity of retinopathy of prematurity by calculation of risk scores or safety indices.

Birth Weight↗