ABSTRACT. Ten years after the foundation of a national diabetic eye screening program in 1980, we have established a low prevalence of blindness and partial sight in type 1 and type 2 diabetics in Iceland. We ask whether the screening program is also associated with a low incidence of blindness in diabetics. We now report the results of a prospective study on the 4-year incidence of diabetic retinopathy and visual impairment in type 1 diabetics with age at onset less than 30 years. Out of 205 patients participating at baseline, 175 patients (85.4%) participated over the full 4-year period. Patients were examined annually and received laser treatment according to Diabetic-and Early Treatment Diabetic Retinopathy Study criteria. The 4-year incidence of any retinopathy was 38.1' 36, of proliferative retinopathy 6.694 and of macular edema 3.4%. Out of 174 patients, 7.4% showed improvement in visual acuity of 2 Snellen lines while 2.5% experienced worsening of visual acuity of 2 Snellen lines during the 4-year period. No diabetic suffered more than 2 lines deterioration of vision and none became legally blind. The incidence of retinopathy in Icelandic type 1 diabetics participating in our annual eye screening program is low and the visual acuity stable. Our results suggest that visual impairment in diabetics can be prevented with active regular screening and standard laser therapy.

Cytogenetic changes are common in breast cancer and have also been described in fibroadenomas and fibrocystic disease, but not in histologically normal breast tissue. Cytogenetic analysis was performed on nonmalignant breast tissue from benign breast lumps (n = 8), reduction mammoplasties (n = 31), and grossly nontumorous tissue from cancerous breasts (n = 84), using standard techniques and G-banding. All samples were reviewed histologically. Clonal chromosomal changes were found in three of eight benign breast tumors (38%). Of the reduction mammoplasties, 17 samples contained nonproliferative changes, and three of these (18%) showed a clonal deletion of 3p. No pathology was identified in the other 14 samples, of which one (7%) contained two clonal changes, apparently balanced translocations. Of nontumorous tissues from cancerous breasts, 15 (18%) showed clonal chromosomal abnormalities. Five of these samples were histologically normal. Two clones were identical to those found in the corresponding cancer. In 18 additional samples, single cells were detected with the same change as that seen in clones or single cells in the cancer. Only 4 of these 20 samples contained detectable cancer cells. Clonal abnormalities found in two or more samples included trisomies X, 7, and 20 and monosomies 19 and 18. Clonal changes were not significantly more frequent in proliferative than in nonproliferative lesions. The Icelandic BRCA2 founder mutation, 999del5, was detected in four samples, all histologically normal, two of which had clonal chromosomal abnormalities. In conclusion, clonal chromosomal changes are not infrequent in nonmalignant breast tissue and can be detected even in the absence of histological abnormalities.

Iron oxide nanoparticles (IONP) are already well-established in the medical field due to their ability to improve contrast in magnetic resonance imaging (MRI) and for their external magnetic control in the body. Moreover, selenium has been shown to kill numerous cancer cells at lower concentrations that IONP (e.g., 1 μg/ml). Selenium is a trace mineral of growing interest in cancer treatment since it is an essential nutrient in the human body and can interfere with thiolcontaining proteins necessary for cancer cells to function. For the above reasons, the goal of this in vitro study was to combine the above chemistries for the first time to develop composite nano-vehicles for magnetically targeted cancer therapy. The suggested design was an IONP core, stabilized by chitosan and decorated with selenium. Two different types of IONP cores were produced. This was followed by different chitosan and selenium coating methods. The particles were characterized for size, shape, zeta potential and magnetic properties. Finally, the most promising products were tested for cancer killing properties on MB-231 breast cancer cells. Results of this pioneering study showed that the most promising iron-selenium nanocomposites consisted of an iron oxide core produced by thermal decomposition, followed by a silane ligand exchange, a chitosan coating and selenium decoration. The particles were 5-9 nm in diameter, with a zeta potential of 29.59 mV and magnetic properties of 35.932 emu/g. Moreover, the novel nanoparticles had concentration dependent cancer killing properties. Specifically, after just 1 day of incubation, breast cancer cell viability was reduced to 40.5% in the presence of 1 μg/ml of these composite nanoparticles (and statistically reduced at even 0.1 μg/ml), without using a chemotherapeutic pharmaceutical drug. This is a significant finding since neither chemotherapeutic pharmaceutical drugs, infrared stimulation, nor magnetism were used. In this manner, this study introduces a brand new composite nanoparticle consisting of iron oxide and selenium which should be further studied for a wide range of magnetically targeted anticancer applications.

SUMMARY A 45, X/46, XY chromosome mosaic is reported in a phenotypic boy fulfilling the criteria for the diagnosis of Russell‐Silver syndrome. Attention is drawn to the relationship between these conditions and congenital asymmetry, in that 45, X/46, XY mosaic and congenital asymmetries share an extremely high incidence of malignancies arising in the organs developing from the urogenital ridge. RÉSUMÉ Mosaique chromosomigue 45, X/46, XY et manifestations du syndrome de Russell‐Silver Une mosaique 45, X/46, XY a été observée chez un garçon présentant phénotypiquement tous les critères permettant de porter le diagnostic du syndrome de Russell‐Silver. L'atten‐tion est attirée sur la relation entre ces conditions et l'asymétrie congénitale, en ce sens que la mosaique 45, X/46, XY et les asymétries congénitales ont en commun une incidence très élevée de tumeur maligne se développant sur les organes provenant de I'ébaucheurogénitale ZUSAMMENFASSUNG 45, X/46, XY Chromosomenmosaik mit Symptomen des Russell‐Silver Syndrom Es wird über ein 45, X/46, XY Mosaik bei einem phänotypisch männlichen Kind mit den Symptomen des Russell‐Silver Syndrom berichtet. Es wird darauf hingewiesen, daß eine Beziehung zwischen diesem Krankheitsbild und der angeborenen Asymmetric besteht, dahingehend daß beim 45, X/46, XY Mosaik und bei den angeborenen Asymmetrien extrem häufig bösartige Tumoren in den Urogenitalorganen auftreten. RESUMEN Mosaicismo con 45, X/46, XY cromosomas con aspecto de síndrome de Russell‐Silver Se aporta un mosaicjsmo con 45, X/46XY en un muchacho con fenotipo quz cumple los criterios para el diagnóstico de síndrome de Russell, Silver. Se atrae la atención sobre la relación entre estas alteraciones y la asimetría congéita, puesto que el mosaicismo y las asirnetrías congénitas comparten una incidencia extremadamente alta de tumores rnalignos desarrollados en los órganos provinentes de la cresta urogenital.

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