Selective elevation of c-{\it myc} RNA transcripts during clonal evolution of N-methyl-N-nitrosourea induced thymic lymphomas in AKR/J mice

Untreated AKR mice develop spontaneous thymic lymphomas by 6-12 months of age. Lymphoma development is accelerated when young mice are injected with the carcinogen N-methyl-N-nitrosourea (MNU). Selected molecular and cellular events were compared during the latent period preceding "spontaneous" (retrovirally-induced) and MNU-induced thymic lymphoma development in AKR mice. These studies were undertaken to test the hypothesis that thymic lymphomas induced in the same inbred mouse strain by endogenous retroviruses and by a chemical carcinogen develop by different mechanisms.^ Immunofluorescence analysis of differentiation antigens showed that most MNU-induced lymphomas express an immature CD4-8+ profile. In contrast, spontaneous lymphomas represent each of the major lymphocyte subsets. These data suggest involvement of different target populations in MNU-induced and spontaneous lymphomas. Analyses at intervals after MNU treatment revealed selective expansion of the CD4-8+ J11d+ thymocyte subset at 8-10 weeks post-MNU in 68% of the animals examined, suggesting that these cells are targets for MNU-induced lymphomagenesis. Untreated age-matched animals showed no selective expansion of thymocyte subsets.^ Previous data have shown that both spontaneous and MNU-induced lymphomas are monoclonal or oligoclonal. Distinct rearrangement patterns of the J$\sb2$ region of the T-cell receptor $\beta$-chain showed emergence of clonal thymocyte populations beginning at 6-7 weeks after MNU treatment. However, lymphocytes from untreated animals showed no evidence of clonal expansion at the time intervals investigated.^ Activation of c-myc frequently occurs during development of B- and T- cell lymphomas. Both spontaneous and MNU-induced lymphomas showed increased c-myc transcript levels. Increased c-myc transcription was first detected at 6 weeks post-MNU, and persisted throughout the latent period. However, untreated animals showed no increases in c-myc transcripts at the time intervals examined. Another nuclear oncogene, c-fos, did not display a similar change in RNA transcription during the latent period.^ These results supports the hypothesis that MNU-induced and spontaneous tumors develop by multi-step pathways which are distinct with respect to the target cell population affected. Clonal emergence and c-myc deregulation are important steps in the development of both MNU-induced and spontaneous tumors, but the onset of these events is later in spontaneous tumor development. ^

Molecular and biochemical analysis of the {\it Drosophila\/} segmentation gene {\it runt\/}

Genetic evidence has indicated that the segmentation gene runt plays a key role in regulating gene expression of the pair-rule genes hairy, even-skipped, and fushi tarazu. In contrast to other pair-rule genes, sequence data of the runt open reading frame did not reveal homologies to DNA-binding motifs of known transcriptional regulatory proteins. This thesis project examined several properties of the runt gene based on the sequence of the transcription unit, including the subcellular localization of the protein in vivo, its ability to bind DNA, and the functionality of a putative nucleotide binding domain.^ A runt-specific antibody was generated and used to demonstrate that runt is localized in the nucleus. Since the precise overlap of the pair-rule stripes is thought to be critical for the determination of cellular identity along the anterior-posterior axis, phasing of early runt expression in the blastoderm was examined with regard to the segmentation genes hairy, even-skipped, and fushi tarazu. runt was also expressed at later stages of embryogenesis, including expression in neuroblasts, and ganglion mother cells of the developing nervous system. Expression at this stage was required for the subsequent formation of specific neurons and runt was extensively expressed in the central and peripheral nervous systems.^ Several experiments were done to address the biochemical function of the runt protein. A direct interaction of runt with DNA was first examined. Although bacterial expressed runt was found to bind dsDNA-cellulose, subsequent experiments failed to detect sequence-specific interactions with DNA. Inter-species conservation of the putative nucleotide binding domain suggested that this region was functionally important, and runt protein bound a labeled ATP analog with high affinity in vitro. Finally, the effect of substitution of a critical residue of the nucleotide binding domain on runt activity was examined in vivo. Ectopic expression of the mutant protein indicated that this conserved substitution altered, but did not eliminate, runt activity as evaluated by segmentation phenotype and viability. ^

The effect of v-{\it mos\/} expression on the regulation of the {\it fos\/} promoter in 490N3T cells

The v-mos oncogene acquired by Moloney murine sarcoma viruses by recombination with the c-mos proto-oncogene encodes a 37kD cytoplasmic serine/threonine protein kinase which can phosphorylate tubulin and vimentin, as well as the cyclin B component of the maturation promotion factor complex (MPF). Our earliest experiments asked whether the v-mos protein could activate the transcription of transin. Since the transcription of transin was known to be mediated by both fos-dependent and fos-independent pathways, it seemed possible that the induction of transin transcription by v-mos might be mediated by p55$\sp{\rm c-}\sp{fos}$. Surprisingly, when we examined the effect of v-mos on the fos promoter, we observed a significant inhibition of transcription in 49ON3T cells, a subclone of N1H3T3 mouse fibroblasts.^ In this thesis we show that in mouse 49ON3T cells, transcription from the fos promoter is up to 10-fold repressed in the presence of v-mos. Moreover, in this cell line several other transforming constructs (v-ras, v-src, neu) also cause repression of the fos promoter. Interestingly, nontransforming oncogenes (e.g. myc) do not repress fos transcription. The repressive effect was lost in v-mos mutants lacking in ATP-binding or kinase domain, arguing that the effect on fos transcription was mediated by v-mos transforming kinase activity. As mos is a cytoplasmic protein, it was assumed that transcriptional repression was mediated by conversion of a transcriptional regulator to a repressor by mos-induced phosphorylation. As a first approximation of the identity of this factor, we mapped the position of the mos effect on the fos promoter using reporter (CAT) constructs. We found that repression was mediated by regions $-$221 to $-$106 and $-$122 to $-$65 relative to the fos transcriptional start site, both of which regions regulate baseline fos transcription. There are direct repeats containing E2F transcriptional activator/repressor recognition motifs in these regions which bind similar nuclear proteins independently of v-mos presence or absence. Our data show that the contribution of the direct repeat to baseline fos transcription is mediated by these E2F sites with perhaps some contribution from the overlapping retinoblastoma control element (RCE). We have shown that there is a separate DNA protein interaction in the direct repeat which is more pronounced in the presence of v-mos. The recognition site for this protein, which we speculate mediates the mos-induced downregulation of fos transcription, overlaps but is distinct from the E2F and RCE binding sites. (Abstract shortened by UMI.) ^

A study of the {\it in vivo\/} role of myogenin

Myogenin is a member of the MyoD family of skeletal muscle specific bHLH transcription factors. All of the members of this family have been shown to initiate the muscle differentiation cascade in a variety of nonmuscle cell lines. Many of the properties of the MyoD family have been studied in vitro, but their in vivo roles had not yet been examined. In this thesis, I study the in vivo role of myogenin by creating mice that carry a mutation at the myogenin locus.^ Mice lacking the myogenin protein are born alive, but immobile. Histological examination showed that these mice are severely deficient in skeletal muscle; they show a reduction in the number and density of myofibers. In addition to the reduction in fiber number, these mice express lower levels of a variety of muscle-specific markers. The undifferentiated cells in the muscle forming regions of these mice do express some muscle-specific markers, indicating that these cells are determined but undifferentiated myoblasts. Additional studies show that the major muscle defect arises late in embryogenesis, at a time coincident with secondary myogenesis. Moreover, studies regarding the nature of the remaining myofibers indicate that they are representative of a normal population of myofibers, merely reduced in numbers. In addition, I studied the effects of combining the myogenin mutation with mutations in two other members of the MyoD family, MyoD and myf5. Mice mutant in myogenin + MyoD and myogenin + myf5 show no increase in the severity of the myogenin single mutation, as indicated by histological or molecular examination. These results reveal the unique and essential role of myogenin in mammalian skeletal myogenesis. ^

Gene expression in sea urchin development: Study of {\it LpS1\/} gene regulation and cloning and characterization of the {\it SpKrox}-{\it 1\/} gene

Cell differentiation are associated with activation of cell lineage-specific genes. The $LpS{\it 1}\beta$ gene of Lytechinus pictus is activated at the late cleavage stage. $LpS{\it 1}\beta$ transcripts accumulate exclusively in aboral ectoderm lineages. Previous studies demonstrated two G-string DNA-elements, proximal and distal G-strings, which bind to an ectoderm-enriched nuclear factor. In order to define the cis-elements which control positive expression of the $LpS{\it 1}\beta$ gene, the regulatory region from $-$108 to +17 bp of the $LpS{\it 1}\beta$ gene promoter was characterized. The ectoderm G-string factor binds to a G/C-rich region larger than the G-string itself and the binding of the G-string factor requires sequences immediately downstream from the G-string. These downstream sequences are essential for full promoter activity. In addition, only 108 bp of $LpS{\it 1}\beta\ 5\sp\prime$ flanking DNA drives $LpS{\it 1}\beta$ gene expression in aboral ectoderm/mesenchyme cells. Therefore, for positive control of $LpS{\it 1}\beta$ gene expression, two regions of 5$\sp\prime$ flanking DNA are required: region I from base pairs $-$762 to $-$511, and region II, which includes the G/C-rich element, from base pairs $-$108 to $-$61. A mesenchyme cell repressor element is located within region I.^ DNA-binding proteins play key roles in determination of cell differentiation. The zinc finger domain is a DNA-binding domain present in many transcription factors. Based on homologies in zinc fingers, a zinc finger-encoding gene, SpKrox-1, was cloned from S. purpuratus. The putative SpKrox-1 protein has all structural characteristics of a transcription factor: four zinc fingers for DNA binding; acidic domain for transactivation; basic domain for nuclear targeting; and leucine zipper for dimerization. SpKrox-1 RNA transcripts showed a transient expression pattern which correlates largely with early embryonic development. The spatial expression of SpKrox-1 mRNA was distributed throughout the gastrula and larva ectodermal wall. However, SpKrox-1 was not expressed in pigment cells. The SpKrox-1 gene is thus a marker of a subset of SMCs or ectoderm cells. The structural features, and the transient temporal and restricted spatial expression patterns suggest that SpKrox-1 plays a role in a specific developmental event. ^

Isolation, characterization and functional analysis of the {\it xnf7\/} gene from {\it Xenopus laevis\/}

A fundamental problem in developmental biology concerns the mechanisms involved in the establishment of the embryonic axis. We are studying Xenopus nuclear factor 7 (xnf7) which we believe to be involved in dorsal-ventral patterning in Xenopus laevis. Xnf7 is a maternal gene product that is retained in the cytoplasm during early embryogenesis until the mid-blastula transition (MBT) when it reenters the nuclei. It is a member of a novel zinc finger proteins, the B-box family, consisting mainly of transcription factors and protooncogenes.^ The xnf7 gene is reexpressed during embryogenesis at the gastrula-neurula stage of development, with its zygotic expression limited to the central nervous system (CNS). In this study we showed that there are two different cDNAs coding for xnf7, xnf7-O and xnf7-B. They differ by 39 amino acid changes scattered throughout the cDNA. The expression of both forms of xnf7 is limited primarily to the central nervous system (CNS) and dorsal axial structures during later stages of embryogenesis.^ In order to study the spatial and temporal regulation of the gene, we screened a Xenopus genomic library using part of xnf7 cDNA as a probe. A genomic clone corresponding to the xnf7-O type was isolated, its 5$\sp\prime$ putative regulatory region sequenced, and its transcriptional initiation site mapped. The putative promoter region contained binding sites for Sp1, E2F, USF, a Pu box and AP1. CAT/xnf7 fusion genes were constructed containing various 5$\sp\prime$ deleted regions of the xnf7 promoter linked to a CAT (Chloramphenicol Acetyl Transferase) reporter vector. These constructs were injected into Xenopus oocytes and embryos to study the regions of the xnf7 promoter responsible for basal, temporal and spatial regulation of the gene. The activity of the fusion genes was measured by the conversion of chloramphenicol to its acetylated forms, and the spatial distribution of the transcripts by whole mount in situ hybridization. We showed that the elements involved in basal regulation of xnf7 lie within 121 basepairs upstream of the transcriptional inititiation site. A DNase I footprint analysis performed using oocyte extract showed that a E2F and 2 Sp1 sites were protected. During development, the fusion genes were expressed following the MBT, in accordance with the timing of the endogenous xnf7 gene. Spatially, the expression of the fusion gene containing 421 basepairs of the promoter was localized to the dorsal region of the embryo in a pattern that was almost identical to that detected with the endogenous transcripts. Therefore, the elements involved in spatial and temporal regulation of the xnf7 gene during development were contained within 421 basepairs upstream of the transcriptional initiation site. Future work will further define the elements involved in the spatial and temporal regulation and the trans-factors that interact with them. ^

The association of genetic groups 1, 2, and 3 of Mycobacterium tuberculosis with pulmonary and extra-pulmonary tuberculosis

Objective. To investigate the association of the three major genetic groups of Mycobacterium tuberculosis with pulmonary and extra-pulmonary tuberculosis in clustered and non-clustered TB cases in the Houston area. ^ Study design. Secondary analysis of an ambi-directional study. ^ Study population. Three hundred fifty-eight confirmed cases of tuberculosis in the Houston that occurred between October 1995 and May 1997, who had been interviewed by the Houston T13 Initiative staff at Baylor College of Medicine, and whose isolates have had their DNA fingerprint and genetic group determined. ^ Exclusions. Individuals whose mycobacterial genotype was unknown, or whose data variables were unavailable. ^ Source of data. Laboratory results, patient interviews, and medical records at clinics and hospitals of the study population. ^ Results. In clustered cases, the majority of both, pulmonary and extra-pulmonary TB cases were caused by genetic group 1. Independent factors were assessed to determine the interactions that may influence the site of infection or increase the risk for one site or another. HIV negative males were protected against extra-pulmonary TB compared to HIV negative females. Individuals ages 1–14 years were at higher risk of having extra-pulmonary TB. Group 3 organisms were found less frequently in the total population in general, especially in extra-pulmonary disease. This supports the evidence in previous studies that this group is the least virulent and genetically distinct from the other two groups. Group 1 was found more frequently among African Americans than other ethnic groups, a trend for future investigations. ^ Among the non-clustered cases, group 2 organisms were the majority of the organisms found in both sites. They were also the majority of organisms found in African Americans, Caucasians, and Hispanics causing the majority of the infections at both sites. However, group 1 organisms were the overwhelming majority found in Asian/Pacific Islander individuals, which may indicate these organisms are either endemic to that area, or that there is an ethnic biological factor involved. This may also be due to a systematic bias, since isolates from individuals from that geographic region lack adequate copies of the insertion sequence IS6110, which leads to their placement in the non-clustered population. ^ The three genetic groups of Mycobacterium tuberculosis were not found equally distributed between sites of infection in both clustered and non-clustered cases. Furthermore, these groups were not distributed in the same patterns among the clustered and non-clustered cases, but rather in distinct patterns. ^

An evaluation of the personal response system program for the elderly in Harris County, Texas

The Personal Response System Program at Huffington Center on Aging, Baylor College of Medicine, provides emergency call systems for elderly people living independently in Houston, Texas. The goal of the project was to complete a formative evaluation of the Personal Response System Program. The specific aims of the evaluation were three-fold. One aim was to evaluate participant health status and level of disability. The second aim was to develop a health care cost estimation strategy. Finally, a preliminary cost-effectiveness analysis was completed to evaluate the program's impact on health care costs and health status among the elderly target population. ^ The evaluation was a longitudinal, randomized experimental design. After the screening of 120 volunteers for eligibility, clients were asked to complete a written questionnaire and a monthly health service contact diary. Volunteers were contacted by telephone interviewers to collect health status information from 100 eligible clients (83%) on three occasions during the six months of follow-up. ^ Initially, volunteers were randomized to two experimental groups. The two groups were found to be comparable at the beginning of the study. No significant differences were detected related to health status, level of disability, or history of physician visits at baseline. However, the group with the Personal Response System (PRS) device had more adverse health events, higher IADL scores, more frequent use of walkers, lower average health status scores, and fewer community volunteers hours than the usual care comparison group. ^ The health care costs were estimated based on an algorithm adapted from the American Medical Association guidelines. Average total health care costs for the group with the PRS device ($912) were greater than the usual care group ($464). However, median health care values for the PRS group ($263) were similar to the usual care comparison group ($234). The preliminary findings indicated that the use of the PRS device was not associated with health care cost savings. ^ In the preliminary cost-effectiveness analysis, use of the personal response system was found to be associated with increased mental health status among elderly clients. The cost-effectiveness evaluation indicated that the associated cost for six months was $710 per unit increase in mental component score when the $150 PRS subscription was included. However, clients with the PRS device were found to have a greater decline in physical health status during the six-month follow-up. The beneficial effect on mental health status was found to be in contrast to negative findings associated with changes in physical health status. The implications for future research relate to the need to identify risk factors among geriatric populations to better target groups that would most likely benefit from PRS Program enrollment. ^

Mean corpuscular volume as a marker for adherence to antiretroviral therapy among HIV infected children and adolescents in Uganda

Mean corpuscular volume, which is an inexpensive and widely available measure to assess, increases in HIV infected individuals receiving zidovudine and stavudine raising the hypothesis that it could be used as a surrogate for adherence.^ The aim of this study was to examine the association between mean corpuscular volume and adherence to antiretroviral therapy among HIV infected children and adolescents aged 0–19 years in Uganda as well as the extent to which changes in mean corpuscular volume predict adherence as determined by virologic suppression.^ The investigator retrospectively reviewed and analyzed secondary data of 158 HIV infected children and adolescents aged 0–19 years who initiated antiretroviral therapy under an observational cohort at the Baylor College of Medicine Children's Foundation - Uganda. Viral suppression was used as the gold standard for monitoring adherence and defined as viral load of < 400 copies/ml at 24 and 48 weeks. ^ Patients were at least 48 weeks on therapy, age 0.2–18.4 years, 54.4% female, 82.3% on zidovudine based regimen, 92% WHO stage III at initiation of therapy, median pre therapy MCV 80.6 fl (70.3–98.3 fl), median CD4% 10.2% (0.3%–28.0%), and mean pre therapy viral load 407,712.9 ± 270,413.9 copies/ml. For both 24 and 48 weeks of antiretroviral therapy, patients with viral suppression had a greater mean percentage change in mean corpuscular volume (15.1% ± 8.4 vs. 11.1% ± 7.8 and 2.3% ± 13.2 vs. -2.7% ± 10.5 respectively). The mean percentage change in mean corpuscular volume was greater in the first 24 weeks of therapy for patients with and without viral suppression (15.1% ± 8.4 vs. 2.3% ± 13.2 and 11.1% ± 7.8 vs. -2.7% ± 10.5 respectively). In the multivariate logistic regression model, percentage change in mean corpuscular volume ≥ 20% was significantly associated with viral suppression (adjusted OR 4.0; CI 1.2–13.3; p value 0.02). The ability of percentage changes in MCV to correctly identify children and adolescents with viral suppression was higher at a cut off of ≥ 20% (90.7%; sensitivity, 31.7%) than at ≥ 9% (82.9%; sensitivity, 78.9%). Negative predictive value was lower at ≥ 20% change (25%; specificity, 84.8%) than at ≥ 9% change (33.3%; specificity, 39.4%).^ Mean corpuscular volume is a useful marker of adherence among children and adolescents with viral suppression. ^

Evaluation of the T-SPOT(RTM).TB test in the diagnosis of latent tuberculosis infection in HIV-infected children in Uganda

Background. About a third of the world’s population is infected with tuberculosis (TB) with sub-Saharan Africa being the worst hit. Uganda is ranked 16th among the countries with the biggest TB burden. The burden in children however has not been determined. The burden of TB has been worsened by the advent of HIV and TB is the leading cause of mortality in HIV infected individuals. Development of TB disease can be prevented if TB is diagnosed during its latent stage and treated with isoniazid. For over a century, latent TB infection (LTBI) was diagnosed using the Tuberculin Skin Test (TST). New interferon gamma release assays (IGRA) have been approved by FDA for the diagnosis of LTBI and adult studies have shown that IGRAs are superior to the TST but there have been few studies in children especially in areas of high TB and HIV endemicity. ^ Objective. The objective of this study was to examine whether the IGRAs had a role in LTBI diagnosis in HIV infected children in Uganda. ^ Methods. Three hundred and eighty one (381) children were recruited at the Baylor College of Medicine-Bristol Meyers Squibb Children’s Clinical Center of Excellence at Mulago Hospital, Kampala, Uganda between March and August 2010. All the children were subjected to a TST and T-SPOT ®.TB test which was the IGRA chosen for this study. Sputum examination and chest x-rays were also done to rule out active TB. ^ Results. There was no statistically significant difference between the tests. The agreement between the two assays was 95.9% and the kappa statistic was 0.7 (95% CI: 0.55–0.85, p-value<0.05) indicating a substantial or good agreement. The TST was associated with older age and higher weight for age z-scores but the T-SPOT®. TB was not. Both tests were associated with history of taking anti-retroviral therapy (ART). ^ Conclusion. Before promoting use of IGRAs in children living in HIV/TB endemic countries, more research needs to be done. ^

Hypogonadism in male cancer patients: A cross-sectional study

Introduction. Cancer is the second most common cause of death in the USA (2). Studies have shown a coexistence of cancer and hypogonadism (9,31,13). The majority of patients with cancer develop cachexia, which cannot be solely explained by anorexia seen in these patients. Testosterone is a male sex hormone which is known to increase muscle mass and strength, maintain cancellous bone mass, and increase cortical bone mass, in addition to improving libido, sexual desire, and fantasy (14). If a high prevalence of hypogonadism is detected in male cancer patients, and a significant difference exists in testosterone levels in cancer patients with cachexia versus those without cachexia, testosterone may be administered in future randomized trials to help alleviate cachexia. Study group and design The study group consisted of male cancer patients and non-cancer controls aged between 40 and 70 years. The primary study design was cross-sectional with a sample size of 135. The present data analysis is done on a subset convenience sample of 72 patients recruited between November 2006 and January 2010. ^ Methods. Patients aged 40-70 years with or without a diagnosis of cancer were recruited into the study. All patients with a BMI over 35, significant edema, non-melanomatous skin cancer, current alcohol or illicit drug abuse, concomitant usage of medications interfering with gonadal axis, and anabolic agents, patients on tube feeds or parenteral nutrition within 3 months prior to enrollment were excluded from the study. The study was approved by the Institutional Review Board of Baylor College of Medicine and is being conducted at the Michael E. DeBakey Veterans Affairs Medical Center at Houston. My thesis is a pilot data analysis that employs a smaller subset convenience sample of 72 patients determined by using the data available for the 72 patients (of the intended sample of 135 patients) recruited between November 2006 and January 2010. The primary aim of this analysis is to compare the proportion of patients with hypogonadism in the male cancer and non-cancer control groups, and to evaluate if a significant difference exists with respect to testosterone levels in male cancer patients with cachexia versus those without cachexia. The procedures of the study relevant to the current data analysis included blood collection to measure levels of testosterone and measurement of body weight to categorize cancer patients into cancer cachexia and cancer non-cachexia sub-groups. ^ Results. After logarithmic transformation of data of cancer and control groups, the unpaired t test with unequal variances was done. The proportion of patients with hypogonadism in the male cancer and non-cancer control groups was 47.5% and 22.7% with a Pearson chi2 statistic of 1.6036 and a p value of 0.205. Comparing the mean calculated Bioavailable testosterone in male cancer patients and non-cancer controls resulted in a t statistic of 21.83 and a p value less than 0.001. When the cancer group alone was taken, the mean free testosterone, calculated bioavailable testosterone and total testosterone levels in the cancer non-cachexia sub-group were 3.93, 5.09, 103.51 respectively and in the cancer cachexia sub-group were 3.58, 4.17, 84.08 respectively. The unpaired t test with equal variances showed that the two sub-groups had p values of 0.2015, 0.1842, and 0.4894 with respect to calculated bioavailable testosterone, free testosterone, and total testosterone respectively. ^ Conclusions. The small sample size of this exploratory study, resulting in a small power, does not allow us to draw definitive conclusions. For the given sub-sample, the proportion of patients with hypogonadism in the cancer group was not significantly different from that of patients with hypogonadism in the control group. Inferences on prevalence of hypogonadism in male cancer patients could not be made in this paper as the sub-sample is small and therefore not representative of the general population. However, there was a statistically significant difference in calculated Bioavailable testosterone levels in male cancer patients versus non-cancer controls. Analysis of cachectic and non-cachectic patients within the male cancer group showed no significant difference in testosterone levels (total, free, and calculated bioavailable testosterone) between both sub-groups. However, to re-iterate, this study is exploratory and the results may change once the complete dataset is obtained and analyzed. It however serves as a good template to guide further research and analysis.^

Implications of Health Care Reform (Medical Ethics Series, 2011)

A video of a panel discussion on how Obama's Health Care Reform would affect Texas Medical Center institutions and health care in general.Speakers include Tom Cole (moderator), Roberta Schwartz (Methodist Hospital), Pauline Rosenau (UT-Houston School of Public Health), and Laurence McCullough (Baylor College of Medicine).

Evaluation of the impact of access to free influenza vaccine on immunization rates for children with cystic fibrosis

Children with cystic fibrosis are at increased risk of seasonal influenza associated complications, which makes them a judicious target of interventions designed to increase influenza vaccination rates. The Baylor College of Medicine/Texas Children's Hospital Pediatric Cystic Fibrosis (BCM/TCH CF) Care Center implemented an enhanced multi-component initiative designed to increase influenza vaccination rates in its patient population during the 2011-2012 influenza season. We evaluated the impact of specific components of this intervention on vaccination rates among the clinic's patient population via a historical medical chart review and examined the relationship between vaccination status and the number of pulmonary exacerbations requiring hospital admission during the influenza season. The multi-component intervention was comprised of providing influenza free of charge in the CF Care Center, reminders via phone call and letters, and drive through influenza vaccine clinics on nights and weekends. The intervention to increase influenza vaccination rates led to overall improved vaccination rates among the patients at the BCM/TCH CF Care Center, increasing from 90% adherence observed during the 2010-2011 season to 94% adherence during the 2011-2012 season. The availability of free influenza vaccine in the CF Care Center, combined with reminders about being vaccinated early in the season proved to be the most effective practices for improving the vaccination rate in the CF Care Center.^

Transcriptional regulation of the {\it neu\/} oncogene and its negative regulation by the c-{\it myc\/} oncogene

The first part of my research involved the characterization of the neu gene promoter. I subcloned a 2.2-kb sequence located upstream to the extreme 5$\sp\prime$ end of the neu gene, in front of the bacterial reporter gene, chloramphenicol acetyltransferase (CAT). Transfection of this construct into different cell lines and subsequent CAT assays demonstrated that this 2.2-kb fragment was functional as a promoter. A series of deletion constructs was engineered to study the contribution of different fragments to transcription. Subcloning of individual fragments was followed by a cotransfection competition experiment, which demonstrated the involvement of protein factors interacting with the promoter. A gel retardation assay was also performed to show the physical binding of protein factors to the promoter. The combined results suggested that both positively and negatively acting protein factors are involved in interacting with different regions of the promoter, contributing to the overall transcription activity. My findings provide an insight into the regulation of neu gene expression, which in turn provides the tools to understand the molecular mechanisms of overexpression of the neu gene in some breast cancer and ovarian cancer cell lines.^ In the second part of my research, I discovered that another oncogene, c-myc, was able to reverse the transformed morphology that was induced by the neu oncogene. Utilizing the promoter constructs that I made, I was able to show that the c-myc oncogene has a negative regulatory effect on the expression of the neu oncogene. Further studies suggested that c-myc is able to lower the effective concentration of a positive factor(s) that interact with a 139-bp fragment of the neu gene promoter. These findings may provide a direct evidence of the long suspected role of the c-myc gene in transcriptional regulation. The neu gene may very well be the first identified mammalian target gene that is regulated by the c-myc oncogene. Since c-myc is known to be stimulated by various mitogenic signals and the neu gene is likely to be a growth factor receptor, it is possible that c-myc, when stimulated by the signal transduction pathway of the neu gene, would function as a negative feedback regulator on the neu gene receptor. (Abstract shortened with permission of author.) ^