Publications

2007

Anderson, F. W. J., Morton, S. U., Naik, S., & Gebrian, B. (2007). Maternal mortality and the consequences on infant and child survival in rural Haiti.. Maternal and Child Health Journal, 11(4), 395-401. (Original work published 2007)

OBJECTIVE: To determine the odds of death of children when a woman of reproductive age dies from maternal or non maternal causes in rural Haiti.

METHODS: Deaths among reproductive aged women between 1997 and 1999 in and around Jeremie, Haiti were classified as maternal or non maternal and matched to female, non-deceasesd controls based on village, age, and parity. Information regarding the health and survival of all of the offspring under 12 years old of the identified women was extracted from the Haitian Health Foundation (HHF) Health Information System (HIS). Additional demographic information was obtained through interviews with the mothers for controls and with family members for cases. Two analyses on child death were conducted; 1) the odds of death for each individual child after a mother's death and 2) the odds of one of the children in a family dying after the mother's death.

FINDINGS: If a family experiences a maternal death, that family has a 55.0% increased odds of experiencing the loss of a child less than 12, whereas when a non maternal death occurs, no increased odds exists. When children of cases were compared to children of controls, mean weight z-scores were the same for the periods corresponding to before and after the maternal deaths. After a maternal death, dosage of BCG (Bacillus Calmette-Guerin) TB (tuberculosis) immunization for the surviving child is significantly lower, as are dosage of measles immunization and the first dose of vitamin A.

CONCLUSIONS: This study shows that a maternal death significantly effects the survival of children in a family in a greater way than a non maternal death.

Mitchell, D. A., Morton, S. U., Fernhoff, N. B., & Marletta, M. A. (2007). Thioredoxin is required for S-nitrosation of procaspase-3 and the inhibition of apoptosis in Jurkat cells.. Proceedings of the National Academy of Sciences of the United States of America, 104(28), 11609-14. (Original work published 2007)

S-nitrosation is a posttranslational, oxidative addition of NO to cysteine residues of proteins that has been proposed as a cGMP-independent signaling pathway [Hess DT, Matsumoto A, Kim SO, Marshall HE, Stamler JS (2005) Nat Rev Mol Cell Biol 6:150-166]. A paradox of S-nitrosation is that only a small set of reactive cysteines are modified in vivo despite the promiscuous reactivity NO exhibits with thiols, precluding the reaction of free NO as the primary mechanism of S-nitrosation. Here we show that a specific transnitrosation reaction between procaspase-3 and thioredoxin-1 (Trx) occurs in cultured human T cells and prevents apoptosis. Trx participation in catalyzing transnitrosation reactions in cells may be general because this protein has numerous protein-protein interactions and plays a key role in cellular redox homeostasis [Powis G, Montfort WR (2001) Annu Rev Pharmacol Toxicol 41:261-295], nitrosothiol content in cells [Haendeler J, Hoffmann J, Tischler V, Berk BC, Zeiher AM, Dimmeler S (2002) Nat Cell Biol 4:743-749], and antiapoptotic signaling.

2006

Mitchell, D. A., Morton, S. U., & Marletta, M. A. (2006). Design and characterization of an active site selective caspase-3 transnitrosating agent.. ACS Chemical Biology, 1(10), 659-65. (Original work published 2006)

The oxidative addition of nitric oxide (NO) to a thiol, S-nitrosation, is a focus of studies on cyclic guanosine monophosphate (cGMP)-independent NO signaling. S-Nitrosation of the catalytic cysteine of the caspase proteases has important effects on apoptosis and consequently has received attention. Here we report on a small molecule that can directly probe the effects of S-nitrosation on the caspase cascade. This chemical tool is capable of permeating the mammalian cell membrane, selectively transnitrosating the caspase-3 active site cysteine, and halting apoptosis in cultured human T-cells. The efficacy of this reagent was compared with the commonly used reagent S-nitrosoglutathione and an esterified derivative.