Commencement 2010 - The Graduate School of Biomedical Sciences

Graduate SchoolofBiomedical SciencesCommencement2009-2010

Children with severe burns areknown to have a massive rise in theirmetabolic rate, also associated withsignificant muscle wasting. Wefound that a three-month aerobicand resistance exercise trainingprogram was safe and did notexacerbate their metabolic rate,whilst helping to improve theirmuscle mass and strength.

I investigated the negative effect of high fatmaternal nutrition and preeclampsia on theoffspring's cardiovascular health as an adult .Pre-pregnancy weight was also shown to bestrong risk factor for preeclampsia. I showedthat maternal obesity strongly influences anoffspring's future health, and if present withpreclampsia has an enhanced detrimentaleffect.

I examined the difference in survivalrates among black and white womenwith late stage breast cancer. I foundthat disease complications directlyrelated to the advanced cancer and itstreatment, immobility and depressiondo not explain the observeddifferences in survival betweengroups.

I studied the potential effectivenessof a Nutrition Education Program onfood choices and dietary selfefficacy (DSE) for adolescents at riskfor Type 2 diabetes. While theProgram did not alter the foodselection by these at riskadolescents, there was a highlysignificant improvement in theirDSE.

KLF4 is a protein involved in maintainingthe structure of the normal humancolon, and is important in thedevelopment of colorectal cancer. Ifocused on how KLF4 regulatesexpression of genes as well as how itmodulates a signaling pathway withincells that is critical in the development ofcolorectal cancer.

Titin is a mechanically important,chain-like protein in muscles. Somesegments of titin are tightly wound uplike coiled rope. Some of these ‘coils’require stronger tugs to unravel thanothers. I used several computerprograms to compare the ‘coils’ andfound differences that might explainwhy some require stronger tugs tounravel.

Lower muscle mass is associated withpoorer outcomes in many clinicalconditions and with aging. Myresearch focuses on understandinghow diet modification and exercisecan be used to increase or maintainmuscle mass during such conditions toimprove clinical outcomes and theoverall quality of life.

Anthrax toxins are capable ofdisrupting cell signaling. Thisdisruption has serious effects on theimmune system. I determined the thatthese toxins altered the properties ofB cells. My results showed that thesetoxins were an important way thatanthrax disables the immune system inproducing disease.

Bacterial pneumonia has adisproportional effect on the elderly.Hospitalizations and pneumoniainpatient mortalities are higher amongmales -75+. Among this group, Hispanicshave more hospitalizations than otherethnic groups. Increasing % of Hispanicsin a county led to lower hospitalizationsand pneumonia inpatient mortalities.Other influencing factors are medianincome and hospital size .

Stroke mortality rates are reported tobe lower for Hispanics than non-Hispanic Whites. My researchexplored the role of immigrant statusin stroke incidence and mortality. Ialso investigated the impact of causeof death ambiguity and the role ofthe misreport of ethnicity on deathcertificates.

Burned children may be predisposedto developing hyperthermia duringexercise. We examined core body andskin temperature during exercise inthe heat. While temperatureresponses are altered, hyperthermiadid not occur. However, thesechildren showed intolerance toexercise in the heat.

My research project used nationalnutrition survey data to comparedietary patterns across race/ethnicsubgroups of the US populationand to examine dietary influenceson race/ethnic differences in type 2diabetes.

HIV infects the brain and can causecognitive impairment. HIV-infectedbrains showed changes in proteasomes,which are responsible for proteindegradation. These changes, associatedwith HIV encephalitis, cognitiveimpairment, and viral loads, were shownin neurons. Findings suggest that theproteasome changes contribute to HIVassociatedcognitive impairment.

Yersinia pestis is the bacteria thatcauses the bubonic plague.Rickettsia typhi, another bacteria,causes a murine typhus. Both aretransmitted to humans and othermammals by fleas. This researchinvestigated mechanisms used bythese bacteria to enhance theirtransmission.

In my research I examine the reasonswhy nerves cannot reconnect in thespinal cord after they are injured. Istudied impaired bladder functionafter spinal injury and found that aknown neurotrophin, Artemin,improved bladder function byfacilitating nerve regeneration andovercoming a known inhibitorybarrier to regeneration.

My dissertation focused on theenergetics and kinetics of NTPbinding and hydrolysis by the E. coliDnaB helicase- replication factorDnaC complex in the absence andpresence of nucleic acid. My resultsshow that a DnaB-DnaC-ssDNAcomplex containing six DnaCmolecules is the recognition complexin the initiation of DNA replication.

My project examined changes in theproportion of older adults withcognitive impairment in the US(1993 – 2004). The prevalence ofcognitive impairment declined overthis period, due to increases ineducation of the population.Declines were greater for blacks andHispanics and lower socioeconomicgroups.

Interferon is important for the clearanceof virus infections. Viruses can escape thisprotective interferon response byblocking specific cellular proteins. I haveshown that although SARS, Hep B andinfluenza viruses interact with the samepattern recognition receptors , they evadethe interferon response by differentmechanisms.

My research reveals important knowledgeof the process of cardiovascular diseases. Idemonstrated that a particular cellorchestrates a new amplification loop ofinflammation that accelerates itsprogression. This novel mechanismhighlights a “backdoor” pathway thatcould be targeted for potentiallyrevolutionary treatments of aneurysms,aortic dissections, and atherosclerosis.

I investigated how immunity developsagainst the parasite Leishmaniabraziliensis, which causes a deadlyand disfiguring disease in SouthAmerica. We determined that theresponses of dendritic cells andmonocytes (cells of the immunesystem) play an important role incontrolling this parasite.

The purpose of this study was toexplore reasons homeless youth turnto substance abuse. Thirteenmetropolitan homeless youth werestudied. The findings fit fivecategories of my grounded theorycentered around a core categorycalled Using, consisting of threephase in the process, namely pre,active, and post substance use.

Bacteria of the genus Rickettsiapossess the ability to invade hostcells and quickly escape the host celldefense mechanisms in order tosurvive. My research led to thediscovery of at least two ways thatRickettsia are able to perform thiscomplex task involving aphospholipase enzyme and ahemolysin protein.

My research evaluated RepliVAX WestNile, a new vaccine for West Nilevirus. I showed that this vaccineprotected animals from West Nileinfection. Studies also showed therole various components of theimmune system play in thedevelopment of immunity from thispromising vaccine.

Cerebral palsy (CP) results instiffness of muscles and decreasedmotion of the knee and ankle,making walking difficult. I assessedknee and ankle motion and walkingability, following SelectivePercutaneous MyofascialLengthening Surgery (SPML) inchildren with spastic CP.

I studied the mechanisms involved inphencyclidine-induced neurotoxicity indeveloping rat brain as a model ofschizophrenia. I showed thatphencyclidine inhibited two keycellular signaling pathways importantfor neuronal survival and that both ofwhich were involved in protectionagainst toxicity by lithium and aknown brain neurotrophic factor.

Injury to a nerve may cause pain. Highlevels of molecules called reactiveoxygen species may help produce painby affecting certain neurons, termedGABAergic, that are normally importantfor pain suppression. My studiesshowed that the function of theseneurons in the spinal cord is decreasedby oxidative stress and that thisdecrease contributes to the stressinduced pain.