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Retention of cellular radiation sensitivity in cell and xenograft lines established from human melanoma surgical specimens
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symptoms is an abnormal regeneration of cholinergic parotid fibers to the sweat glands. A variety of surgical interventions has been described in interrupt aberrant communication between the secretomotor parotid fibers and the sweat gland. The authors describe their experience with a prophylactic approach to Frey’s syndrome that is performed as part of the parotidectomy. The authors interpose a flap of the superficial aponeurotic system (SMAS) between the parotid bed and skin flap. In a prospective study in 55 patients, the flap was elevated and used if there was no compromise in tumor excision. In all cases at follow-up there was no evidence of Frey’s syndrome. The authors hypothesize that this flap prevents the regrowth of the nerve fibers into the sweat glands. This is an effective means of preventing an otherwise disabling problem and warrants replication by other surgeons.
Gold Eyelid Weights in Patients With Facial Palsy: A Patient Review. SA Kelly, DT Sharpe. Plastic Reconst Surg 89:436-440, 1992 Complete facial palsy is accompanied by open eyes with danger to the integrity of the cornea. A recently popularized technique for eye closure is achieved by the effect of gravity when the levator palpebrae superior is relaxed. This method uses a gold eyelid weight that was first described in 1966. The present report details the results of 31 patients who underwent this procedure over a 26-year period. Surprisingly, there was a 68% incidence of complications, including infection 7%, loss of position 18%, and extrusion 43%. Extrusion occurred a long time after insertion, even as late as 46 months. This did not prevent replacement of a new weight. One reason for the high rate of extrusion may be the use of a laterally situated incision. Currently most authors are using medially placed incisions. The high rate of extrusion may also represent a foreign body reaction. More recently, the weight has been fixed to the tarsal plate with a permanent suture and this may decrease the extrusion rate. This article is a rather frank description of the complications encountered by one group and should be studied by anyone who uses this popular technique.
Retention of Cellular Radiation Sensitivity in Cell and Xenograft Lines Established From Human Melanoma Surgical Specimens. EK Rofstad. Cancer Res 52:1764-1769, 1992 Human tumor cell lines can be established in monolar cultures and human cell lines transplanted serially into nude mice. These can be used for model systems in the study of radiation biology of certain tumors. Six melanoma lines were previously established and retain several biologic fea-
ABSTRACTS
tures of the donor patient tumors, eg, cell ultrastructure and tumor histology. This report investigates to what extent the cellular radiation sensitivity of the donor patient tumors were retained during serial transplantation of these lines. Cellulary radiation sensitivity of the cells were measured in vitro using several mathematical models. The donor tumors differed considerably in radiation sensitivity, as would be expected from the biologic behavior of melanoma. The xenograft lines showed similar survival curves in cultures as well as following transplantation. These were not significantly different from that of the donor patient tumors regardless of which survival parameter was used. Because recurrent melanoma is notoriously difficult to treat, this novel model system offers great promise to examine the radiobiologic properties of metatastic melanoma.
Natural History of Intraepitbelial Neoplasia in Humans With Implications for Cancer Chemoprevention Strategy. CW Boone, GJ Kelloff, VE Steele. Cancer Res 52:1651-1659, 1992 Human epithelial neoplasia begins as a focal, clonal overgrowth of morphologically altered stem cells. A better understanding of human intraepithelial neoplasia is critical to investigate the effectiveness of chemoprevention. This clonal overgrowth is the target condition for which drugs are being sought to arrest progression. The current article nicely reviews and examines the issues relevant to the natural history of intraepithelial neoplasia using different models. One model is the mouse skin papillomas induced by application of chemicals. This model is associated with cells of increased nuclear size and nuclear atypia. Disordered genetic makeup has also been found in many human epithelial tumors in association with other forms of genetic instability. Two examples of the induction of regression of intraepithelial neoplasia include treatment of oral leukoplakia with carotenoids or retinoic acid. Chemoprevention seeks to prevent invasive neoplasia. Chemopreventive drugs may prevent epithelial hyperproliferation either by blocking stimulated proliferation or suppressing the process of proliferation itself. In addition to developing good models of intraepithelial neoplasia, the authors point out the need for biomarkers to be used that parallel the appearance of abnormal cells. These biomarkers can be proliferating cell antigens or differentiation specific antigens. It would be highly desirable if a group of biomarkers could be developed that correlate with the presence of neoplasia and that can be followed in an objective and quantitative manner. Such biomarkers would be expected to disappear concurrently with the regression of lesions. More research is needed on the induction of regression of intraepithelial neoplasia. This sound review examines critical issues in un-
symptoms is an abnormal regeneration of cholinergic parotid fibers to the sweat glands. A variety of surgical interventions has been described in interrupt aberrant communication between the secretomotor parotid fibers and the sweat gland. The authors describe their experience with a prophylactic approach to Frey’s syndrome that is performed as part of the parotidectomy. The authors interpose a flap of the superficial aponeurotic system (SMAS) between the parotid bed and skin flap. In a prospective study in 55 patients, the flap was elevated and used if there was no compromise in tumor excision. In all cases at follow-up there was no evidence of Frey’s syndrome. The authors hypothesize that this flap prevents the regrowth of the nerve fibers into the sweat glands. This is an effective means of preventing an otherwise disabling problem and warrants replication by other surgeons.
Gold Eyelid Weights in Patients With Facial Palsy: A Patient Review. SA Kelly, DT Sharpe. Plastic Reconst Surg 89:436-440, 1992 Complete facial palsy is accompanied by open eyes with danger to the integrity of the cornea. A recently popularized technique for eye closure is achieved by the effect of gravity when the levator palpebrae superior is relaxed. This method uses a gold eyelid weight that was first described in 1966. The present report details the results of 31 patients who underwent this procedure over a 26-year period. Surprisingly, there was a 68% incidence of complications, including infection 7%, loss of position 18%, and extrusion 43%. Extrusion occurred a long time after insertion, even as late as 46 months. This did not prevent replacement of a new weight. One reason for the high rate of extrusion may be the use of a laterally situated incision. Currently most authors are using medially placed incisions. The high rate of extrusion may also represent a foreign body reaction. More recently, the weight has been fixed to the tarsal plate with a permanent suture and this may decrease the extrusion rate. This article is a rather frank description of the complications encountered by one group and should be studied by anyone who uses this popular technique.
Retention of Cellular Radiation Sensitivity in Cell and Xenograft Lines Established From Human Melanoma Surgical Specimens. EK Rofstad. Cancer Res 52:1764-1769, 1992 Human tumor cell lines can be established in monolar cultures and human cell lines transplanted serially into nude mice. These can be used for model systems in the study of radiation biology of certain tumors. Six melanoma lines were previously established and retain several biologic fea-
ABSTRACTS
tures of the donor patient tumors, eg, cell ultrastructure and tumor histology. This report investigates to what extent the cellular radiation sensitivity of the donor patient tumors were retained during serial transplantation of these lines. Cellulary radiation sensitivity of the cells were measured in vitro using several mathematical models. The donor tumors differed considerably in radiation sensitivity, as would be expected from the biologic behavior of melanoma. The xenograft lines showed similar survival curves in cultures as well as following transplantation. These were not significantly different from that of the donor patient tumors regardless of which survival parameter was used. Because recurrent melanoma is notoriously difficult to treat, this novel model system offers great promise to examine the radiobiologic properties of metatastic melanoma.
Natural History of Intraepitbelial Neoplasia in Humans With Implications for Cancer Chemoprevention Strategy. CW Boone, GJ Kelloff, VE Steele. Cancer Res 52:1651-1659, 1992 Human epithelial neoplasia begins as a focal, clonal overgrowth of morphologically altered stem cells. A better understanding of human intraepithelial neoplasia is critical to investigate the effectiveness of chemoprevention. This clonal overgrowth is the target condition for which drugs are being sought to arrest progression. The current article nicely reviews and examines the issues relevant to the natural history of intraepithelial neoplasia using different models. One model is the mouse skin papillomas induced by application of chemicals. This model is associated with cells of increased nuclear size and nuclear atypia. Disordered genetic makeup has also been found in many human epithelial tumors in association with other forms of genetic instability. Two examples of the induction of regression of intraepithelial neoplasia include treatment of oral leukoplakia with carotenoids or retinoic acid. Chemoprevention seeks to prevent invasive neoplasia. Chemopreventive drugs may prevent epithelial hyperproliferation either by blocking stimulated proliferation or suppressing the process of proliferation itself. In addition to developing good models of intraepithelial neoplasia, the authors point out the need for biomarkers to be used that parallel the appearance of abnormal cells. These biomarkers can be proliferating cell antigens or differentiation specific antigens. It would be highly desirable if a group of biomarkers could be developed that correlate with the presence of neoplasia and that can be followed in an objective and quantitative manner. Such biomarkers would be expected to disappear concurrently with the regression of lesions. More research is needed on the induction of regression of intraepithelial neoplasia. This sound review examines critical issues in un-