RESUMEN

BACKGROUND: Ocular melanoma is a rare but often deadly malignancy that arises in the uvea, conjunctiva, or orbit. Uveal melanoma is the most common type, with conjunctival melanoma being the second most frequently observed. Melanoma accounts for 5-10% of metastatic or secondary orbital malignancies, but only a minute proportion of primary orbital neoplasia. The aim of this study was to characterize the clinical presentation, treatment, and prognosis in patients presenting with melanoma metastatic to, or secondary within, the orbit. METHODS: A retrospective cohort study of patients presenting to a tertiary referral orbital unit from 1982 to 2016 was performed. Eighty-nine patients with biopsy-proven diagnosis of melanoma within the orbit were included in the study. The clinical notes, radiological imaging, histology, surgical notes, and outcome data for the patients were reviewed. The main outcome measures of interest were the interval between primary malignant melanoma and orbital presentation, survival after orbital presentation, and clinical parameters (such as gender, age at presentation, and treatment approach). RESULTS: The commonest primary source of tumor was choroidal melanoma, with conjunctival and cutaneous melanomas being relatively common; eyelid and naso-sinus tumors occurred in a few cases. The mean age at presentation with orbital disease was 65 years (31-97 years). The interval between primary malignancy and orbital disease (either local spread/recurrence or true metastatic disease) showed wide variability, with almost one-third of patients having orbital disease at the time of primary diagnosis, but others presenting many years later; indeed, the longest orbital disease-free interval was over 34 years. Twenty-three patients were considered to have had late orbital metastases-that is, at more than 36 months after primary tumor. The median survival following presentation with orbital involvement was 24 months. Patients with tumors of cutaneous origin had worst survival, whereas those with conjunctival tumors had the best prognosis. CONCLUSION: A high index of suspicion for orbital recurrence should be maintained in any patient with prior history of melanoma, however distant the primary tumor is in site or time. Furthermore, giving a prognosis for orbital melanoma remains problematic due to highly variable survival, and further investigation will be necessary to understand the likely genetic basis of this phenomenon.

RESUMEN

Biological clocks have evolved as an adaptation to life on a rhythmic planet, synchronising physiological processes to the environmental light-dark cycle. Here we examine circadian clock function in Mexican blind cavefish Astyanax mexicanus and its surface counterpart. In the lab, adult surface fish show robust circadian rhythms in per1, which are retained in cave populations, but with substantial alterations. These changes may be due to increased levels of light-inducible genes in cavefish, including clock repressor per2. From a molecular standpoint, cavefish appear as if they experience 'constant light' rather than perpetual darkness. Micos River samples show similar per1 oscillations to those in the lab. However, data from Chica Cave shows complete repression of clock function, while expression of several light-responsive genes is raised, including DNA repair genes. We propose that altered expression of light-inducible genes provides a selective advantage to cavefish at the expense of a damped circadian oscillator.

Asunto(s)

RESUMEN

PURPOSE: There is little published data on pregnancy outcomes in women who had conceived spontaneously after age 45 years. The aim of this review is to provide accurate information on the risks and probable outcomes of spontaneously conceived pregnancies in women over the age of 45 years, which will enable clinicians to counsel such women appropriately, carry out adequate risk assessment, and ensure better care for pregnancies in this population. DESIGN: A literature search was performed using EmBase and PubMed for English language articles published between 1970 and 2011, with extractable data on mothers aged ≥45 at the time of delivery and with ≥95% spontaneous conception in the study population. RESULTS: Six such studies with a total pooled number of 505 women were identified. Overall, there is increased maternal morbidity and rates of caesarean section, as well as higher incidence of premature births and admission to special care baby unit. Contrary to popular belief, career is not always an important factor in delaying childbearing, especially in developing countries. Other factors may include cultural acceptance of large families and lack of contraception, although more research may be carried out in order to explain these hypotheses. CONCLUSION: Pooled retrospective data suggest that women who conceived spontaneously after the age of 45 years have increased maternal morbidity and rates of caesarean section, as well as higher incidence of premature births and admission to special care baby unit.

Asunto(s)