Sixto García Castiñeiras, MD. Ph.D. Professor,
Depts. of Ophthalmology and Biochemistry
University of Puerto Rico, Medical Sciences Campus, School of Medicine
Tel. (787) 758-2525 Ext. 1934
Fax: (787) 274-8724 Dept. Biochemistry
Age-related cataract biochemistry.

1967, Complutense, Madrid
Ph.D., 1976, University of Puerto Rico, Medical School
Phone: (787) 758-2525 ext. 1934

Research Interests

Main research interest is centered around the biochemistry of age-related cataracts, specifically including (1) postsynthetic modifications of lens proteins; (2) chemistry and immunochemistry of lens pigments; (3) metabolic interactions of the lens with surrounding ocular fluids and tissues, particularly those involving antioxidants, redox-active metabolites and oxidative stress end-products (ascorbate, proteins, hydrogen peroxide, malondialdehyde, glutathione and other sulfhydryls, etc.); (4) immunogenicity of lens proteins.

Interest in the biochemistry of oxidative stress in the eye led to increasing attention given to human cardiovascular diseases (coronary artery disease, atherosclerosis, cardiac failure) and their underlying biochemical mechanisms, including the metabolism of homocysteine.

For analytical purposes, high performance liquid chromatography (HPLC) has been amply used to accomplish these research objectives. HPLC methods have been developed in the laboratory to support clinical research in human inborn errors of metabolism and hereditary diseases.

Selected Publications

  • Garcia-Castineiras, S., Dillon, J. and Spector, A. Detection of bityrosine in cataractous human lens protein. Science, 199: 897-899 (1978).PubMed Entry
  • Garcia-Castineiras, S. and Miranda-Rivera, M.N. Loss of free amino groups in the water-soluble fraction of nuclear senile cataracts. Invest. Ophthal. Vis. Sci., 24: 1181-1187 (1983).PubMed Entry
  • Figueroa-Nieves, R., Kessler, M.J. and Garcia-Castineiras, S. in vivo transfer of ascorbate and dehydroascorbate to the aqueous humor of the eye in the domestic cat and the rhesus monkey. PR Health Sci J., 3: 141-153 (1985).
    Garcia-Castineiras, S., Velazquez, S., Martinez, P. and Torres, N. Aqueous humor hydrogen peroxide analysis with dichlorophenol-indophenol. Exp. Eye Res., 55: 9-20 (1992).PubMed Entry
  • Cuevas, A.A. and Garcia Castineiras, S. Melanins and lens pigments: a comparative study. PR Health Sci. J. 12: 129-135 (1993).PubMed Entry
  • Diaz-Velez, C.R., Garcia-Castineiras, S., Mendoza-Ramos, E. and Hernandez-Lopez E. Increased malondialdehyde In peripheral blood of patients with congestive heart failure. Am. Heart J. 1996; 131: 146-152. PubMed Entry