Introduction of a normal human chromosome 6 into human melanoma cell lines results in suppression of tumorigenicity. This suggests that a gene(s) on chromosome 6 controls the malignant phenotype of human melanoma. Because antioxidants can suppress the tumor-promotion phase of carcinogenesis, and because the antioxidant enzyme manganese superoxide dismutase (MnSOD) has been localized to a region of chromosome 6 frequently lost in melanomas, we have examined the effect of transfecting sense and antisense human MnSOD cDNAs into melanoma cell lines. Cell lines expressing abundant (+)-sense MnSOD-5 cDNAs significantly altered their phenotype in culture and lost their ability to form colonies in soft agar and tumors in nude mice. In contrast, the introduction of antisense MnSOD or +psv2neo had no effect on melanoma tumorigenicity. These findings indicate that stable transfection of MnSOD cDNA into melanoma cell lines exerts a biological effect that mimics that observed after introduction of an entire human chromosome 6.
The OS-MRS was found to stratify mortality risk in 4431 patients from 4 validation centers that were nonparticipants in the original defining cohort study. The score represents the first validated scoring system for risk stratification in bariatric surgery and is anticipated to aid informed consent discussions, guide surgical decision-making, and allow standardization of outcome comparisons between treatment centers.
In a review of 125 percutaneous endoscopic gastrostomies (PEG) and 88 Stamm gastrostomies performed at Duke University Medical Center since 1978, the average operating room time for PEG (50 +/- 20 min) was shorter than for Stamm (96 +/- 26 min) (p less than 0.0001). General anesthesia was administered in only 13% of PEG placements compared with 64% of Stamm gastrostomies. The cost of PEG was about $1000 less than for Stamm gastrostomies. The average time after surgery until use of the feeding tube was 1.8 days for PEG compared with 3.4 days for Stamm (p less than 0.0001). The overall complication rate after PEG was 8.8% (4.0% major) compared with 23.9% for Stamm gastrostomies (10.2% major) (p less than 0.005). PEG reduces operative time, necessity for general anesthesia, expense of insertion, incidence of complications, and requires less recovery time before use. PEG is the procedure of choice for gastric feeding access.
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