Comparison between different prognostic models to be used for metastatic bone disease on appendicular skeleton in a Chilean population.

PURPOSE: Several preoperation prognosis models used on the treatment of metastatic bone disease on appendicular skeleton have been devised. The purpose of this study was to compare the performance of different survival prognostic models on patients with metastatic bone disease in long bones in a Chilean population. METHODS: This is a multicentric retrospective study. We retrospectively reviewed the medical records of 136 patients who were confirmed with metastatic bone disease of the appendicular skeleton and who were treated surgically from 2016 to 2019. The minimum follow-up time was 12 months. All patients were assessed using four appendicular metastatic bone disease scoring systems. A preoperative predicted survival time for all 136 patients was retrospectively calculated making use of the revised Katagiri, PathFx, Optimodel and IOR score model. RESULTS: The PathFx model demonstrated an accuracy at predicting 3 (area under the curve [AUC] = 0.61) and 6-month (AUC = 0.65) survival time after surgical management. IOR score model demonstrated an accuracy at predicting 12-month survival time (AUC = 0.64). The survival rate reached the 44% in a year. The median survival time to death or last follow-up time was 14.9 months (SD ± 15). CONCLUSION: PathFx score model demonstrated the highest accuracy at predicting a survival time of 3 and 6 months. IOR score model was the most accurate measure at predicting a survival time of 12-months. To our knowledge, this is the first study reporting a comparative analysis of metastatic bone disease with predicting models in a country located in Latin America. PathFx's and IOR score models are the ones to be used in the Chilean population as the predictive models in metastatic bone disease of the appendicular skeleton.

[Effects of vitamin C administration on cholesterol gallstone formation]. / Efecto de la ingesta de vitamina C en el proceso de formación de cálculos biliares de colesterol.

BACKGROUND: Biliary cholesterol is transported by vesicles and micelles. Cholesterol microcrystals are derived from thermodynamically unstable vesicles. In experimental animals vitamin C deficiency leads to a super-saturation of biliary cholesterol and to the formation of gallstones. AIM: To search for a possible relationship between serum levels of vitamin C and the formation of cholesterol gallstones in patients with cholelithiasis. MATERIAL AND METHODS: Thirteen patients with cholelithiasis and a programmed surgical intervention were treated with 2 g/day of vitamin C per os for two weeks before surgery. Forty nine patients subjected to a cholecystectomy not supplemented with vitamin C were studied as controls. Plasma concentrations of vitamin C and lipid profiles were measured. The cholesterol saturation index, crystallization time, cholesterol and phospholipid content in vesicles and micelles, separated by gel filtration chromatography, were studied in bile samples obtained from the gallbladder. RESULTS: Vitamin C supplementation did not change significantly plasma lipids and bile lipid concentrations. However, in supplemented patients, significant reductions in vesicular cholesterol content (6.5 ± 4.8% compared to 17.9 ± 14.0% in the control group; p < 0.05) and vesicular cholesterol/phospholipid ratio (0.71 ± 0.53 compared to 1.36 ± 1.15 in controls; p < 0.05), were observed. CONCLUSIONS: Vitamin C administration may modify bile cholesterol crystallization process, the first step in cholesterol gallstone formation.

Efecto de la ingesta de vitamina C en el proceso de formación de cálculos biliares de colesterol / Effects of vitamin C administration on cholesterol gallstone formation

Background: Biliary cholesterol is transported by vesicles and micelles. Cholesterol microcrystals are derived from thermodynamically unstable vesicles. In experimental animals vitamin C deficiency leads to a super-saturation of biliary cholesterol and to the formation of gallstones. Aim: To search for a possible relationship between serum levels of vitamin C and the formation of cholesterol gallstones in patients with cholelithiasis. Material and Methods: Thirteen patients with cholelithiasis and a programmed surgical intervention were treated with 2 g/day of vitamin C per os for two weeks before surgery. Forty nine patients subjected to a cholecystectomy not supplemented with vitamin C were studied as controls. Plasma concentrations of vitamin C and lipid profiles were measured. The cholesterol saturation index, crystallization time, cholesterol and phospholipid content in vesicles and micelles, separated by gel filtration chromatography, were studied in bile samples obtained from the gallbladder. Results: Vitamin C supplementation did not change significantly plasma lipids and bile lipid concentrations. However, in supplemented patients, significant reductions in vesicular cholesterol content (6.5 ± 4.8% compared to 17.9 ± 14.0% in the control group; p < 0.05) and vesicular cholesterol/phospholipid ratio (0.71 ± 0.53 compared to 1.36 ± 1.15 in controls; p < 0.05), were observed. Conclusions: Vitamin C administration may modify bile cholesterol crystallization process, the first step in cholesterol gallstone formation.