5 Clinical Trials for Various Conditions
Minimal human data exist on actual liver vitamin A compared with blood biomarkers. One blood biomarker, the percent of total serum retinol (vitamin A) in the form of retinyl esters, has been suggested to diagnose hypervitaminosis A with cutoffs of 5% and 10%. In this study, investigators aim to compare total liver vitamin A reserves with the percent total serum retinol as retinyl esters to evaluate hypervitaminosis A using autopsy samples from US adults. Investigators also evaluate the sensitivity (the ability of the biomarker to correctly identify those with deficiency) and specificity (the ability of the biomarker to correctly identify those without deficiency) of serum retinol to determine vitamin A deficiency, variation of liver vitamin A concentration among lobes, and liver alpha retinyl ester concentrations, a cleavage product of alpha-carotene, a vitamin A precursor. To conduct the study, matched serum and liver samples were procured from 27 US adult cadavers (from donors age 49-101 years) and their vitamin A biomarkers were analyzed.
The purpose of this research study is to see if the amount of vitamin D in ones blood makes it more or less likely to develop thyroid gland toxicity when being treated with immunotherapy that blocks the activity of proteins called programed death-1(PD-1) or programmed death ligand-1 (PD-L1). Immunotherapy is treatment that makes changes to the immune system to try to fight cancer. Immunotherapy treatments that block the activity of important parts of the immune system called PD-1 and PD-L1 are used to standardly treat many different types of cancer and can cause thyroid toxicity in certain people. In this study the treatment for your cancer is not research treatment but standard of care determined by your oncologist. Blood will be drawn before starting treatment to determine the amount of Vitamin D and also to assess thyroid function. Also questionnaires will be completed before starting treatment and while on treatment to assess symptoms you are experiencing.
To evaluate the safety and tolerability of two supplements in healthy subjects taken daily for six months.
RATIONALE: Donepezil and vitamin E may be able to decrease side effects caused by radiation therapy given to prevent brain metastases in patients with small cell lung cancer. It is not yet known if donepezil and vitamin E are effective in preventing side effects caused by radiation therapy to the head. PURPOSE: Randomized phase III trial to determine the effectiveness of donepezil and vitamin E in preventing side effects caused by radiation therapy given to prevent brain metastases in patients who have small cell lung cancer.
RATIONALE: 13 Cis retinoic acid may prevent the development of cancer cells. PURPOSE: Randomized double-blinded phase II trial to study the effectiveness of 13-cis retinoic acid with or without vitamin E for chemoprevention or observation of cancer in persons at high risk of developing lung cancer.