Long-term follow-up of invasive ocular surface squamous cell carcinoma treated with excision, cryotherapy, and topical mitomycin C

Background

To evaluate the efficacy of surgical excision, cryotherapy and topical Mitomycin C (MMC) for ocular surface squamous cell carcinoma (SCC) with at least 24?months follow-up.

Methods

Seventeen patients with primary and recurrent invasive SCC of ocular surface underwent surgical excision and map biopsy of the margins, and double freeze-thaw cryotherapy of the bed and margins. Topical MMC (0.04%, 4 times daily) was commenced 7–10?days after operation. It was delivered in cycles that consisted of medication 4 times daily for 7 consecutive days followed by 7 consecutive days of no medication. Patients with primary SCC received two cycles (protocol 1) and those with recurrent SCC received three cycles (protocol 2). Patients with intra-ocular and or orbital extension or those with less than 24?months of follow-up were excluded. The frequency of tumor recurrence and complications associated with treatment were measured.

Results

Mean age was 70.7?years (SD?=?10, range: 48–80). Mean follow-up time was 48?months (SD?=?21, range: 24–89). There were 12 patients with primary SCC and five with recurrent SCC. Mean largest diameter was 9.7?mm (3–20). Surgical margins were free in 12 cases. One patient with recurrent SCC who received protocol 2 treatment developed recurrence 9?months after excision, and remained free of recurrence 24?months after second treatment. Complications comprised transient mild punctate corneal epithelial erosion (eight), irritation and conjunctival hyperemia (11), corneal scar (six), and scleral thinning (three). All except one responded well to conservative management. One scleral thinning required scleral patch graft 1?year after treatment.

Conclusion

The combination of surgical excision, cryotherapy, and post-operative topical mitomycin-C was effective treatment for ocular surface invasive SCC in long-term follow-up.     

Assessment of oestrogenic potency of chemicals used as growth promoter by in-vitro methods

Three in-vitro bioassays were used to compare the oestrogenic potency of chemicals used as growth promoter in beef cattle in certain non-European Union countries (17beta-oestradiol, alpha-zearalanol, testosterone, trenbolone, trenbolone acetate, melengestrol acetate) or found as food contaminant such as the mycotoxin zearalenone and some of their metabolites (17alpha-oestradiol, oestrone, 17alpha-epitestosterone, 19-nortestosterone, androstendione, zearalanone, alpha-zearalanol, beta-zearalanol, alpha-zearalenol, beta-zearalenol). The strong oestrogens 17alpha-ethinyl oestradiol and diethylstilboestrol were used as standards. The first bioassay was based on the activation of a reporter gene by oestrogens in recombinant yeast expressing human or rainbow trout oestrogen receptor. In the second bioassay, the vitellogenin gene induction of rainbow trout hepatocyte cultures was used as a biomarker for the exposure to oestrogens. The third bioassay was based on the alkaline phosphatase gene induction by oestrogens in the human endometrial Ishikawa cell line. The assessment of oestrogenic potency of these chemicals clearly demonstrates the strong oestrogenicity of the mycotoxin zearalenone and its metabolites and particularly alpha-zearalenol which was as potent as ethinyl oestradiol and diethylstilboestrol in the human endometrial Ishikawa cell line.     

Remarkable capacity for perception of the direction of skin pull in man

We determined the ability to appreciate the direction of a skin pull caused by a moving pin that was glued to the forearm skin. A majority of the subjects were able to tell the direction of pin movements with an excursion of 0.13 mm (≥66% correct responses, p<0.05). Local skin anaesthesia showed that stretch sensitive receptors located over 15 mm in front and behind the pin correctly signalled the direction of these minute skin pulls. It was concluded that information about patterns of skin stretch is an important component of the somatosensory system that may contribute not only to kinaesthetic, but also to cutaneous sensations.     

Synthesis of estrogens in progenitor cells of adult fish brain: Evolutive novelty or exaggeration of a more general mechanism implicating estrogens in neurogenesis?

In contrast to other vertebrates, in which the adult brain shows limited adult neurogenesis, teleost fishes exhibit an unparalleled capacity to generate new neurons as adults, suggesting that their brains present a highly permissive environment for the maintenance and proliferation of adult progenitors. Here, we examine the hypothesis that one of the factors permitting establishment of this favourable environment is estradiol. Indeed, recent data showed that radial glial cells strongly expressed one of two aromatase duplicated genes. Aromatase is the estrogen-synthesizing enzyme and this observation is of great interest, given that radial glial cells are progenitor cells capable of generating new neurons. Given the well-documented roles of estrogens on cell fate, and notably on cell proliferation, these data suggest that estradiol could be involved in maintaining and/or activating these progenitors. Examination of recent data in birds and mammals suggests that the situation in fish could well be an exaggeration of a more general mechanism implicating estrogens in neurogenesis. Indeed, there is accumulating evidence that estrogens are involved in embryonic, adult or reparative neurogenesis in other vertebrates, notably in mammals.     

Effective production of carcinoembryonic antigen by conversion of the membrane-bound into a recombinant secretory protein by site-specific mutagenesis

Carcinoembryonic antigen (CEA), the most widely used human tumor marker, is a heavily glycosylated protein over-expressed by a wide range of tumors. It has been indicated that CEA might be a useful target for human anti-tumor immunotherapy. CEA assay for research as well as clinical trials demands a continuous source of CEA protein preparations. In a multi-purpose research program to provide a reliable source for large production of CEA, we converted the membrane-bound carcinoembryonic antigen into a secretory protein by site-specific mutagenesis. We made the secretory CEA protein by introducing a new stop codon at 99 bp upstream of the original stop codon in CEA cDNA by PCR-based mutagenesis. The glycosylation of recombinant CEA proteins, especially those destined for administration to human trials is crucially important. To produce CEA with the same glycosylation pattern and immunogenicity as the native CEA expressed by human tumorsin vivo, the truncated CEA cDNA which does not encode the last C-terminal 33-amino acid hydrophobic domain was transfected into HT29, a human colon carcinoma cell line by the calcium phosphate method. Stable transfectants were selected and pooled. CEA secretion from the cells was verified by analysis of the transfectant culture supernatant for CEA protein. As determined by ELISA, 16 μg/L of recombinant CEA was secreted per 10⁶ transfectants within 48 hrs, an increase over 40 times relative to the untransfected cells. The size of the recombinant CEA secreted by HT29 transfectants in our experiment is identical to that of reference CEA secreted from tumors and is fully antigenic. It seems that the C-terminal truncation does not affect CEA glycosylation in HT29 cells. It is predicted that human cancer immunotherapy using recombinant CEA expressed in this system would be more effective than the commercial protein which is usually prepared from bacterial or other heterologous expression systems.