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C J Schultz

Publications and source records attributed to C J Schultz.

41 records · Page 3Linked to original sources
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Carcinoma of the larynx in patients with gastroesophageal reflux.

PURPOSE: To study the relationship between gastroesophageal reflux disease (GERD) and the development of laryngeal cancer in patients who lack other accepted risk factors for the development of squamous cell carcinoma of the larynx. PATIENTS AND METHODS: A retrospective review of patients either treated surgically or with radiation therapy for stage 1 or stage 2 laryngeal carcinoma with specific reference to smoking history and the presence of GERD. RESULTS: We present 9 lifetime nonsmoking patients with stage 1 or 2 laryngeal carcinoma in whom GERD was clinically and/or radiographically shown. Also, 14 patients are identified who quit smoking more than 15 years before the development of laryngeal cancer and who also had evidence of GERD. CONCLUSION: We propose that the development of laryngeal carcinoma in this cohort of patients who lack typical risk factors supports the notion that GERD plays a role in the etiology of carcinoma of the larynx. Because the accepted risk factors for laryngeal carcinoma such as smoking and alcohol use increase the likelihood of reflux, GERD may act as a cocarcinogen in smokers and drinkers. Of interest, the treatment of GERD can reverse the signs of chronic laryngitis and should be instituted in patients with laryngeal pathology who have GERD.

Adult↗
PubMedDate not supplied

Iododeoxyuridine radiosensitization of human glioblastoma cells exposed to acute and chronic gamma irradiation: mechanistic implications and clinical relevance.

PURPOSE: Iododeoxyuridine (IdUrd) is a recognized sensitizer of sparsely and some densely ionizing radiations. The mechanism of sensitization remains uncertain. Sensitization is likely to involve increased production of DNA damage and/or inhibition of DNA damage repair. To test these possibilities, we have characterized acute and chronic radiosensitization, and the sublethal damage repair capacity of two human glioblastoma cell lines, with or without clinically relevant concentrations of IdUrd. MATERIALS AND METHODS: Exponentially growing human glioblastoma cell lines, G18 and U251, were irradiated with acute (1.4 Gy/min) and chronic (20, 40, and 80 cGy/hr) cobalt 60 exposures in the presence and absence of 0 to 10 microM IdUrd. Clonogenic survival was determined. Sensitizer enhancement ratios and global survival curve comparisons were determined with and without IdUrd. Repair half-times for chronic exposures with and without IdUrd were calculated. Split-dose recovery following acute fractions of 5 Gy separated by 0, 0.5, 1, 2, and 5 hours was evaluated. RESULTS: Following acute exposure, a sensitizer enhancement ratio at 10% survival of 1.85 and 1.75 was observed at concentrations of 10 microM IdUrd for the G18 and U251 cell lines, respectively. A global comparison of the survival curves similarly revealed significant sensitization at 10 microM IdUrd. Sensitizer enhancement ratios and global comparisons of the chronic exposures showed significant sensitization in the presence of 2 microM IdUrd for both lines. No significant interaction between dose rate and IdUrd effect could be shown using a global comparison. Repair half-times for chronic exposures were similar in the presence or absence of IdUrd. Both cell lines demonstrate capacity for sublethal damage repair in the presence of 2 microM IdUrd in split-dose experiments. CONCLUSION: The results of the chronic clonogenic and split-dose studies suggest that increased DNA damage production contributes to the mechanism of IdUrd radio-sensitization, perhaps more so than repair inhibition. A capacity for sublethal damage repair is not necessarily a prerequisite for sensitization. IdUrd remains an attractive sensitizer of ionizing irradiation delivered at high or low dose rates, particularly for actively growing tumors located in quiescent normal tissues.

DNA Damage↗