Gestational diabetes mellitus (GDM) is defined as glucose intolerance of various degrees that is first detected during pregnancy. GDM is detected through the screening of pregnant women for clinical risk factors and, among at-risk women, testing for abnormal glucose tolerance that is usually, but not invariably, mild and asymptomatic. GDM appears to result from the same broad spectrum of physiological and genetic abnormalities that characterize diabetes outside of pregnancy. Indeed, women with GDM are at high risk for having or developing diabetes when they are not pregnant. Thus, GDM provides a unique opportunity to study the early pathogenesis of diabetes and to develop interventions to prevent the disease.

AIDS patients who develop lymphoma are often treated with transplanted hematopoietic progenitor cells. As a first step in developing a hematopoietic cell-based gene therapy treatment, four patients undergoing treatment with these transplanted cells were also given gene-modified peripheral blood-derived (CD34(+)) hematopoietic progenitor cells expressing three RNA-based anti-HIV moieties (tat/rev short hairpin RNA, TAR decoy, and CCR5 ribozyme). In vitro analysis of these gene-modified cells showed no differences in their hematopoietic potential compared with nontransduced cells. In vitro estimates of successful expression of the anti-HIV moieties were initially as high as 22% but declined to approximately 1% over 4 weeks of culture. Ethical study design required that patients be transplanted with both gene-modified and unmanipulated hematopoietic progenitor cells obtained from the patient by apheresis. Transfected cells were successfully engrafted in all four infused patients by day 11, and there were no unexpected infusion-related toxicities. Persistent vector expression in multiple cell lineages was observed at low levels for up to 24 months, as was expression of the introduced small interfering RNA and ribozyme. Therefore, we have demonstrated stable vector expression in human blood cells after transplantation of autologous gene-modified hematopoietic progenitor cells. These results support the development of an RNA-based cell therapy platform for HIV.

To examine the role of breast cancer stem cells (BCSCs) in metastasis, we generated human-in-mouse breast cancer orthotopic models using patient tumor specimens, labeled with optical reporter fusion genes. These models recapitulate human cancer features not captured with previous models, including spontaneous metastasis in particular, and provide a useful platform for studies of breast tumor initiation and progression. With noninvasive imaging approaches, as few as 10 cells of stably labeled BCSCs could be tracked in vivo, enabling studies of early tumor growth and spontaneous metastasis. These advances in BCSC imaging revealed that CD44(+) cells from both primary tumors and lung metastases are highly enriched for tumor-initiating cells. Our metastatic cancer models, combined with noninvasive imaging techniques, constitute an integrated approach that could be applied to dissect the molecular mechanisms underlying the dissemination of metastatic CSCs (MCSCs) and to explore therapeutic strategies targeting MCSCs in general or to evaluate individual patient tumor cells and predict response to therapy.

OBJECTIVE

The outcome of patients with hepatocellular carcinoma (HCC) remains poor because of late diagnosis. The aim of this study was to compare the accuracy of alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) in the early diagnosis of HCC.

METHODS

Among 1031 patients randomized in the Hepatitis C Antiviral Long-term Treatment Against Cirrhosis (HALT-C) Trial, a nested case-control study of 39 HCC cases (24 early stage) and 77 matched controls was conducted to compare the performance of AFP and DCP. Testing was performed on sera from 12 months prior (month -12) to the time of HCC diagnosis (month 0).

RESULTS

The sensitivity and specificity of DCP at month 0 was 74% and 86%, respectively, at a cutoff of 40 mAU/mL and 43% and 100%, respectively, at a cutoff of 150 mAU/mL. The sensitivity and specificity of AFP at month 0 was 61% and 81% at a cutoff of 20 ng/mL and 22% and 100% at a cutoff of 200 ng/mL. At month -12, the sensitivity and specificity at the low cutoff was 43% and 94%, respectively, for DCP and 47% and 75%, respectively, for AFP. Combining both markers increased the sensitivity to 91% at month 0 and 73% at month 12, but the specificity decreased to 74% and 71%, respectively. Diagnosis of early HCC was triggered by surveillance ultrasound in 14, doubling of AFP in 5, and combination of tests in 5 patients.

CONCLUSIONS

Biomarkers are needed to complement ultrasound in the detection of early HCC, but neither DCP nor AFP is optimal.

OBJECTIVE

The objective of this study was to compare insulin resistance relative to body fat and the associated compensatory responses in 57 healthy children living in Los Angeles, California (14 Caucasians, 15 African-Americans, and 28 Hispanics).

METHODS

Insulin sensitivity and acute insulin response were determined by intravenous glucose tolerance test. Insulin secretion, hepatic insulin extraction, and insulin clearance were estimated by C-peptide and insulin modeling.

RESULTS

Insulin sensitivity was significantly lower in Hispanics and African-Americans compared with Caucasian children, and acute insulin response was significantly higher in African-American children. No ethnic differences were noted in the first-phase secretion, but second-phase insulin secretion was significantly higher in Hispanic children than in African-American children (200 +/- 53 vs. 289 +/- 41 nmol/min; P = 0.03). The greater acute insulin response in African-Americans, despite lower secretion, was explained by a lower hepatic insulin extraction in African-Americans compared with Hispanics (36.6 +/- 2.9 vs. 47.3 +/- 2.2%; P = 0.0006).

CONCLUSIONS

In conclusion, Hispanic and African-American children are more insulin resistant than Caucasian children, but the associated compensatory responses are different across ethnic groups.

OBJECTIVE

Rituximab is an effective treatment in patients with established rheumatoid arthritis (RA). The objective of the IMAGE study was to determine the efficacy of rituximab in the prevention of joint damage and its safety in combination with methotrexate (MTX) in patients initiating treatment with MTX.

METHODS

In this double-blind randomised controlled phase III study, 755 MTX-naïve patients with active RA were randomly assigned to MTX alone, rituximab 2×500 mg + MTX or rituximab 2×1000 mg + MTX. The primary end point at week 52 was the change in joint damage measured using a Genant-modified Sharp score.

RESULTS

249, 249 and 250 patients were randomly assigned to MTX alone, rituximab 2×500 mg + MTX or rituximab 2×1000 mg + MTX, respectively. At week 52, treatment with rituximab 2×1000 mg + MTX compared with MTX alone was associated with a reduction in progression of joint damage (mean change in total modified Sharp score 0.359 vs 1.079; p=0.0004) and an improvement in clinical outcomes (ACR50 65% vs 42%; p<0.0001); rituximab 2×500 mg + MTX improved clinical outcomes (ACR50 59% vs 42%; p<0.0001) compared with MTX alone but did not significantly reduce the progression of joint damage. Safety outcomes were similar between treatment groups.

CONCLUSIONS

Treatment with rituximab 2×1000 mg in combination with MTX is an effective therapy for the treatment of patients with MTX-naïve RA. ClinicalTrials.gov identifier NCT00299104.

High hepatic iron concentration (HIC) is associated with cardiac iron overload. However, simultaneous measurements of heart and liver iron often demonstrate no significant linear association. We postulated that slower rates of cardiac iron accumulation and clearance could reconcile these differences. To test this hypothesis, we examined the longitudinal evolution of cardiac and liver iron in 38 thalassemia major patients, using previously validated magnetic resonance imaging (MRI) techniques. On cross-sectional evaluation, cardiac iron was uncorrelated with liver iron, similar to previous studies. However, relative changes in heart and liver iron were compared with one another using a metric representing the temporal delay between them. Cardiac iron significantly lagged liver iron changes in almost half of the patients, implying a functional but delayed association. The degree of time lag correlated with initial HIC (r = 0.47, P < .003) and initial cardiac R2* (r = 0.57, P < .001), but not with patient age. Thus, longitudinal analysis confirms a lag in the loading and unloading of cardiac iron with respect to liver iron, and partially explains the weak cross-sectional association between these parameters. These data reconcile several prior studies and provide both mechanical and clinical insight into cardiac iron accumulation.

BACKGROUND

The Cystic Fibrosis Questionnaire-Revised (CFQ-R) is a validated patient-reported outcome (PRO) containing both generic scales and scales specific to cystic fibrosis (CF). The minimal clinically important difference (MCID) score for a PRO corresponds to the smallest clinically relevant change a patient can detect. MCID scores for the CFQ-R respiratory symptom (CFQ-R-Respiratory) scale were determined using data from two 28 day, open-label, tobramycin inhalation solution (TIS) studies in patients with CF and chronic Pseudomonas aeruginosa airway infection. At study enrollment, patients in the study 1-exacerbation had symptoms indicative of pulmonary exacerbation (n = 84; < 14 years of age, 31 patients;>> or = 14 years of age, 53 patients); patients in study 2-stable had stable respiratory symptoms (n = 140; < 14 years of age, 14 patients;>> or = 14 years, 126 patients).

METHODS

The anchor-based method utilized a global rating-of-change questionnaire (GRCQ) that assessed patients' perceptions of change in their respiratory symptoms after TIS treatment. The mean change from baseline CFQ-R-Respiratory scores were mapped onto the GRCQ to estimate the MCID. The two distribution-based methods were as follows: (1) 0.5 SD of mean change in CFQ-R-Respiratory scores (baseline to end of TIS treatment); and (2) 1 SEM for baseline CFQ-R-Respiratory scores. Triangulation of these three estimates defined the MCIDs.

RESULTS

MCID scores were larger for patients in study 1-exacerbation (8.5 points) than for those in study 2-stable (4.0 points), likely reflecting differences in patient disease status (exacerbation/stable) between these studies.

CONCLUSIONS

Patient benefit from new and current CF therapies can be evaluated using changes in CFQ-R-Respiratory scores. Using the MCID provides a systematic way to interpret these changes, and facilitates the identification of CF treatments that improve both symptoms and physiologic variables, potentially leading to better treatment adherence and clinical outcomes. Trial registration (study 1-exacerbation): Australian-New Zealand Clinical Trials Registry Identifier: ACTRN 12605000602628 Trial registration (study 2-stable): ClinicalTrials.gov Identifier: NCT00104520.

A clinical trial of retroviral-mediated transfer of the adenosine deaminase (ADA) gene into umbilical cord blood CD34(+) cells was started in 1993. ADA-containing peripheral blood mononuclear cells (PBMCs) have persisted in patients from this trial, with T lymphocytes showing the highest prevalence of gene marking. To gain a greater understanding of the nature and number of the transduced cells that were engrafted, we used linear amplification-mediated PCR (LAM-PCR) to identify clonal vector proviral integrants. In one patient, a single vector integrant was predominant in T lymphocytes at a stable level over most of the eight-year time span analyzed and was also detected in some myeloid samples. T-cell clones with the predominant integrant, isolated after eight years, showed multiple patterns of T-cell receptor (TCR) gene rearrangement, indicating that a single pre-thymic stem or progenitor cell served as the source of the majority of the gene-marked cells over an extended period of time. It is important to distinguish the stable pattern of monoclonal gene marking that we observed here from the progressive increase of a T-cell clone with monoclonal gene marking that results from leukemic transformation, as observed in two subjects in a clinical trial of gene therapy for X-linked severe combined immunodeficiency (SCID).

Therapy-related myelodysplasia or acute myeloid leukemia (t-MDS/AML) is a major complication of cancer treatment. We compared gene expression in CD34+ cells from patients who developed t-MDS/AML after autologous hematopoietic cell transplantation (aHCT) for lymphoma with controls who did not develop t-MDS/AML. We observed altered gene expression related to mitochondrial function, metabolism, and hematopoietic regulation in pre-aHCT samples from patients who subsequently developed t-MDS/AML. Progression to overt t-MDS/AML was associated with additional alterations in cell-cycle regulatory genes. An optimal 38-gene PBSC classifier accurately distinguished patients who did or did not develop t-MDS/AML in an independent group of patients. We conclude that genetic programs associated with t-MDS/AML are perturbed long before disease onset, and accurately identify patients at risk for this complication.

OBJECTIVE

Although the antiviral and histological benefits of peginterferon/ribavirin therapy are well established, the effects on health-related quality of life (HRQOL) and sexual health are less certain. This study assessed HRQOL and sexual health in patients with advanced fibrosis or cirrhosis in the HALT-C Trial.

METHODS

Subjects completed SF-36 and sexual health questionnaires prior to and after 24 weeks of peginterferon/ribavirin therapy (n=1144). Three hundred and seventy-three (33%) subjects were HCV RNA negative at week 20 and continued therapy through week 48; 258 were seen at week 72. One hundred and eighty achieved sustained virological responses (SVR) and 78 relapsed.

RESULTS

At baseline, patients had poorer scores for all eight SF-36 domains compared to healthy controls. Patients with cirrhosis had lower HRQOL scores than those with bridging fibrosis, as did patients with higher depression scores. SVR patients had significant improvements in seven domains, whereas relapsers had significant worsening in one domain. Sexual scores improved in SVR patients and decreased in relapsers (p=0.03). In multivariate analyses, improvements in HRQOL and sexual scores were significantly associated with SVR but were less striking in patients with lower depression scores.

CONCLUSIONS

Achievement of SVR after peginterferon/ribavirin therapy improves HRQOL and sexual health in chronic hepatitis C patients with advanced fibrosis or cirrhosis.

Patients with locally advanced/inflammatory breast cancer (LABC/IBC) face a high likelyhood of recurrence and prognosis for relapsed, or de novo stage IV metastatic breast cancer (MBC) remains poor. Estrogen (ER) and HER2 receptor expression on primary or MBC allow targeted therapies, but an estimated 10-18% of tumors do not exhibit these biomarkers and survival in these cases is even poorer. Variations in discordance rates for the expression of ER and HER2 receptors have been observed between primary and metastatic tumors and such discordances may lead to suboptimal treatment. Circulating tumor cells (CTCs) are considered the seeds of residual disease and distant metastases and their characterization could help guide treatment selection. To explore this possibility, we used multiple biomarker assessment of CTCs in comparison to primary and metastatic tumor sites. Thirty-six patients with LABC/IBC, or stage IV MBC were evaluated. Blood samples were procured prior to initiating or changing therapy. CTCs were identified based on presence of cytokeratin and nucleus staining, and the absence of CD45. A multimarker assay was developed to simultaneously quantify expression of HER2, ER, and ERCC1, a DNA excision repair protein. Novel fiber-optic array scanning technology (FAST) was used for sensitive location of CTCs. CTCs were detected in 82% of MBC and 62% LABC/IBC cases. Multiplex marker expression was successfully carried out in samples from18 patients with MBC and in 8 patients with LABC/IBC that contained CTCs. In MBC, we detected actionable discordance rates of 40 and 23%, respectively for ER and HER2 where a biomarker was negative in the primary or metastatic tumor and positive in the CTCs. In LABC/IBC, actionable discordances were 60 and 20% for ER and HER2, respectively. Pilot trials evaluating the effectiveness of treatment selections based on actionable discordances between biomarker expression patterns on CTCs and primary or metastatic tumor sites may allow for a prospective assessment of CTC-based individualized targeted therapies.

OBJECTIVE

To examine changes in risk factors in overweight and obese Hispanic children at high risk of developing type 2 diabetes.

METHODS

We recruited 128 overweight/obese Hispanic children with a family history of type 2 diabetes primarily from clinics in East Los Angeles. Children were evaluated annually for 4 years with an oral glucose tolerance test, applying American Diabetes Association criteria to define diabetes and pre-diabetes. Insulin sensitivity (S(i)), acute insulin response (AIR) to glucose, and beta-cell function (BCF) were determined from frequently sampled intravenous glucose tolerance tests, and total body fat by dual-energy X-ray absorptiometry and intra-abdominal and subcutaneous abdominal adipose tissue (IAAT and SAAT) by magnetic resonance imaging were assessed in years 1, 2, and 4.

RESULTS

No subjects developed type 2 diabetes, 40% never had pre-diabetes, 47% had intermittent pre-diabetes with no clear pattern over time, and 13% had persistent pre-diabetes. At baseline, those with persistent pre-diabetes had lower BCF and higher IAAT. In repeated measures, S(i) deteriorated regardless of pre-diabetes, and there was a significant effect of pre-diabetes on AIR (42% lower in pre-diabetes; P = 0.01) and disposition index (34% lower in pre-diabetes; P = 0.021) and a significant interaction of pre-diabetes and time on IAAT (greater increase over time in those with pre-diabetes; P = 0.034).

CONCLUSIONS

In this group of Hispanic children at high risk of type 2 diabetes, 1) pre-diabetes is highly variable from year to year; 2) the prevalence of persistent pre-diabetes over 3 years is 13%; and 3) children with persistent pre-diabetes have lower BCF, due to a lower AIR, and increasing visceral fat over time.

OBJECTIVE

Visceral adipose tissue (VAT) and hepatic fat are associated with insulin resistance and vary by sex and ethnicity. Recently, pancreatic fat fraction (PFF) has also been linked with increasing obesity. Our aim was to assess ethnic and sex differences in PFF and its relationship to other fat depots, circulating free fatty acids (FFA), insulin secretion and sensitivity, and inflammation in obese adolescents and young adults.

METHODS

We examined 138 (40 males, 98 females) obese Hispanics and African Americans (13-25 years). Subcutaneous adipose tissue and VAT volumes, hepatic fat fraction (HFF), and PFF were determined by magnetic resonance imaging. Insulin sensitivity and β-cell function were assessed during an intravenous glucose tolerance test.

RESULTS

Hispanics had higher PFF than African Americans (7.3 ± 3.8 vs. 6.2 ± 2.6%, P = 0.03); this ethnic difference was higher in young adults compared with children and adolescents (ethnicity × age: P = 0.01). Males had higher PFF than females (P < 0.0001). PFF was positively correlated with VAT (r = 0.45, P < 0.0001), HFF (r = 0.29, P < 0.0001), and FFA (r = 0.32, P = 0.001). PFF positively correlated with inflammatory markers but lost significance when adjusted for VAT. In multiple stepwise regression analysis, VAT and FFA were the best predictors of PFF (adjusted R(2) = 0.40). There were no significant correlations between PFF and markers of insulin sensitivity or β-cell function.

CONCLUSIONS

PFF is higher in Hispanics than African Americans, and this difference increases with age. In young obese individuals, PFF is related to VAT, HFF, and circulating FFA, thus possibly contributing to their increased risk for type 2 diabetes and related metabolic disorders.

Combination treatment with pegylated-interferon-alpha (PEG IFN-alpha) and ribavirin, the current recommended therapy for chronic hepatitis C virus (HCV) infection, results in a sustained virological response (SVR) in only about half of patients. Because genes involved in the interferon-alpha pathway may affect antiviral responses, we analyzed the relationship between variants in these genes and SVR among participants in the Hepatitis C Antiviral Long-Term treatment Against Cirrhosis (HALT-C) trial. Patients had advanced chronic hepatitis C that had previously failed to respond to interferon-based treatment. Participants were treated with peginterferon-alpha2a and ribavirin during the trial. Subjects with undetectable HCV RNA at week 72 were considered to have had an SVR. Subjects with detectable HCV RNA at week 20 were considered nonresponders. We used TaqMan assays to genotype 56 polymorphisms found in 13 genes in the interferon-alpha pathway. This analysis compares genotypes for participants with an SVR to nonresponders. The primary analysis was restricted to European American participants because a priori statistical power was low among the small number (n = 131) of African American patients. We used logistic regression to control the effect of other variables that are associated with treatment response. Among 581 European American patients, SVR was associated with IFNAR1 IVS1-22G (adjusted odds ratio, 0.57; P = 0.02); IFNAR2 Ex2-33C (adjusted odds ratio, 2.09; P = 0.02); JAK1 IVS22+112T (adjusted odds ratio, 1.66; P = 0.04); and ADAR Ex9+14A (adjusted odds ratio, 1.67; P = 0.03). For the TYK2-2256A promoter region variant, a borderline association was present among European American participants (OR, 1.51; P = 0.05) and a strong relationship among African American patients; all 10 with SVR who were genotyped for TYK2 -2256 carried the A variant compared with 68 of 120 (57%) nonresponders (P = 0.006).

CONCLUSIONS

Genetic polymorphisms in the interferon-alpha pathway may affect responses to antiviral therapy of chronic hepatitis C.

OBJECTIVE

Prospective studies of serum hepatocellular carcinoma (HCC) biomarkers in patients with advanced hepatitis C are lacking. The aim of this study was to determine the frequencies and performance of elevated α-fetoprotein (AFP), AFP-L3, and des-γ-carboxy prothrombin (DCP) levels as HCC biomarkers in advanced hepatitis C.

METHODS

Patients in the HALT-C Trial were tested every 3 months for 42 months. Screening ultrasound was performed every 12 months. Levels of biomarkers were compared in patients in whom HCC did or did not develop.

RESULTS

In all, 855 patients were evaluated; HCC developed in 46. Among patients without HCC, 73.2% had AFP consistently <20, 24.5% had at least one AFP between 20 and 199, and 2.3% had at least one AFP value ≥200 ng/ml; 73.7% had DCP consistently <90, 11.6% had at least one DCP between 90 and 149, and 14.7% had at least one DCP value ≥150 mAU/ml. AFP-L3 ≥10% was present at least once in 9.0% and in 17.1% of those with AFP ≥20 ng/ml. Among all patients with elevated biomarkers, a diagnosis of HCC was made in 0-31.6% (depending on the biomarker and cutoff) during the subsequent 24 months. AFP ≥200 ng/ml had the highest specificity (99%), but sensitivity was ≤20%. DCP ≥40 mAU/ml had the highest sensitivity (76%), but specificity was ≤58%. Independent predictors of elevated AFP were gender (female), race (Black), more advanced disease, and HCC. Elevated DCP was associated with more advanced disease and HCC.

CONCLUSIONS

Mild-moderate elevations in total AFP and DCP but not in AFP-L3 occur frequently in patients with chronic hepatitis C and advanced fibrosis, are related to factors other than HCC, and are poor predictors of HCC.

Progress in developing effective gene transfer approaches to treat HIV-1 infection has been steady. Many different transgenes have been reported to inhibit HIV-1 in vitro. However, effective translation of such results to clinical practice, or even to animal models of AIDS, has been challenging. Among the reasons for this failure are uncertainty as to the most effective cell population(s) to target, the diffuseness of these target cells in the body, and ineffective or insufficiently durable gene delivery. Better understanding of the HIV-1 replicative cycle, host factors involved in HIV-1 infection, vector biology and application, transgene technology, animal models, and clinical study design have all contributed vastly to planning current and future strategies for application of gene therapeutic approaches to the treatment of AIDS. This review focuses on the newest developments in these areas and provides a strong basis for renewed optimism that gene therapy will have an important role to play in treating people infected with HIV-1.

OBJECTIVE

To evaluate the efficacy/safety of belimumab in patients with rheumatoid arthritis (RA).

METHODS

Patients fulfilling American College of Rheumatology (ACR) criteria for RA for ≥ 1 year who had at least moderate disease activity while receiving stable disease-modifying antirheumatic drug (DMARD) therapy and failed ≥ 1 DMARD were randomly assigned to placebo or belimumab 1, 4, or 10 mg/kg, administered intravenously on Days 1, 14, and 28, and then every 4 weeks for 24 weeks (n = 283). This was followed by an optional 24-week extension (n = 237) in which all patients received belimumab. Primary efficacy endpoint was the Week 24 ACR20 response.

RESULTS

Week 24 ACR20 responses with placebo and belimumab 1, 4, and 10 mg/kg were 15.9%, 34.7% (p = 0.010), 25.4% (p = 0.168), and 28.2% (p = 0.080), respectively. Patients taking any belimumab dose who continued with belimumab in the open-label extension had an ACR20 response of 41% at 48 weeks. A similar ACR20 response (42%) at 48 weeks was seen in patients taking placebo who switched in the extension to belimumab 10 mg/kg. Greater response rates were observed in patients who at baseline were rheumatoid factor-positive, anticitrullinated protein antibody-positive, or tumor necrosis factor inhibitor-naive, or had elevated C-reactive protein levels, Disease Activity Score 28>> 5.1, or low B lymphocyte stimulator levels (< 0.858 ng/ml). Adverse event rates were similar across treatment groups.

CONCLUSIONS

In this phase II trial, belimumab demonstrated efficacy and was generally well tolerated in patients with RA who had failed previous therapies. [ClinicalTrials.gov identifier NCT00071812].

BACKGROUND

Few studies have investigated the association between sugar intake and insulin dynamics in children, and none have examined this association in overweight Latino youth.

OBJECTIVE

We aimed to examine the relation between dietary components, especially sugar intake, and insulin dynamics in overweight Latino youth.

METHODS

We examined 63 overweight Latino children aged 9-13 y. Dietary intake was determined by 3-d records, and body composition was measured with dual-energy X-ray absorptiometry. Insulin sensitivity (S(I)), acute insulin response (AIR), and disposition index (an index of beta cell function) were measured by using a frequently sampled intravenous-glucose-tolerance test and minimal modeling. Hierarchical regression analysis ascertained the potential independent relation between insulin dynamics and dietary components.

RESULTS

The relation between macronutrient intake and any variable related to insulin dynamics was not significant. However, higher total sugar intake, although not related to S(I), was significantly associated with lower AIR (beta = -0.296, P = 0.045) and lower beta cell function (beta = -0.421, P = 0.043), independent of the covariates age, sex, body composition, Tanner stage, and energy intake. Sugar-sweetened beverage intakes trended toward inverse association with lower AIR (beta = -0.219, P = 0.072) and beta cell function (beta = -0.298, P = 0.077).

CONCLUSIONS

In overweight Latino children, higher intakes of sugar and sugar-sweetened beverages were associated with lower AIR and disposition index, which suggested that these children already have early signs of poor beta cell function. These results emphasize the need for early nutritional interventions to reduce daily sugar intake in overweight Latino children and potentially reduce their risk for type 2 diabetes.

OBJECTIVE

Therapy-related myelodysplasia or acute myelogenous leukemia (t-MDS/AML) is a lethal complication of autologous hematopoietic stem-cell transplantation (aHCT) for Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). Here, we investigated the hypothesis that accelerated telomere shortening after aHCT could contribute to the development of t-MDS/AML.

METHODS

A prospective longitudinal cohort was constructed to investigate the sequence of cellular and molecular abnormalities leading to development of t-MDS/AML after aHCT for HL/NHL. This cohort formed the sampling frame for a nested case-control study to compare changes in telomere length in serial blood samples from patients who developed t-MDS/AML with matched controls who did not develop t-MDS/AML.

RESULTS

An initial increase in telomere length at day 100 after aHCT was followed by an accelerated telomere shortening in t-MDS/AML patients when compared with controls. These telomere alterations preceded the onset of t-MDS and were independent of other known risk factors associated with development of t-MDS/AML on multivariate analysis. Additionally, we observed reduced generation of committed progenitors in patients who developed t-MDS/AML, indicating that these telomere alterations were associated with reduced regenerative capacity of hematopoietic stem cells.

CONCLUSIONS

The development of t-MDS/AML after aHCT is associated with and preceded by markedly altered telomere dynamics in hematopoietic cells. Accelerated telomere loss in patients developing t-MDS/AML may reflect increased clonal proliferation and/or altered telomere regulation in premalignant cells. Genetic instability associated with shortened telomeres may contribute to leukemic transformation in t-MDS/AML.

OBJECTIVE

Trastuzumab is a monoclonal antibody targeted to the Her2 receptor and approved for treatment of Her2-positive breast cancer. Among patients who initially respond to trastuzumab therapy, resistance typically arises within 1 year. BT/Her(R) cells are trastuzumab-resistant variants of Her2-positive BT474 breast cancer cells. The salient feature of BT/Her(R) cells is failure to downregulate phosphoinositide 3-kinase/Akt signaling on trastuzumab binding. The current work addresses the mechanism of sustained signaling in BT/Her(R) cells, focusing on the protein kinase A (PKA) pathway.

METHODS

We performed microarray analysis on BT/Her(R) and BT474 cell lines to identify genes that were upregulated or downregulated in trastuzumab-resistant cells. Specific genes in the PKA pathway were quantified using reverse transcription-PCR and Western hybridization. Small interfering RNA transfection was used to determine the effects of gene knockdown on cellular response to trastuzumab. Electrophoretic mobility shift assays were used to measure cyclic AMP-responsive element binding activity under defined conditions. Immunohistochemistry was used to analyze protein expression in clinical samples.

RESULTS

BT/Her(R) cells had elevated PKA signaling activity and several genes in the PKA regulatory network had altered expression in these cells. Downregulation of one such gene, the PKA-RIIalpha regulatory subunit, conferred partial trastuzumab resistance in Her2-positive BT474 and SK-Br-3 cell lines. Forskolin activation of PKA also produced significant protection against trastuzumab-mediated Akt dephosphorylation. In patient samples, PKA signaling appeared to be enhanced in residual disease remaining after trastuzumab-containing neoadjuvant therapy.

CONCLUSIONS

Activation of PKA signaling may be one mechanism contributing to trastuzumab resistance in Her2-positive breast cancer. We propose a molecular model by which PKA confers its effects.

OBJECTIVE

With the limited efficacy of current therapy for chronic hepatitis C, modifiable risk factors for liver disease progression are important to identify. Because obesity is associated with liver disease, we examined the effects of weight-related conditions on disease outcomes in the Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis (HALT-C) trial.

METHODS

Of 1050 patients, 985 could be evaluated for predefined progression of liver disease not related to hepatocellular carcinoma. Clinical outcomes were determined over 3.5 years for all patients and progression to cirrhosis on protocol biopsy among patients who had bridging fibrosis (56.5% of cohort) at entry.

RESULTS

At study entry, median body mass index was high (29.2 kg/m(2)) and accompanied by other weight-related conditions, including diabetes (24.9%), high median waist circumference, and insulin resistance (by updated homeostasis model assessment of insulin resistance; HOMA2-IR). Among noninvasive measures, HOMA2-IR was most strongly associated with outcomes with hazard ratio (HR) of 1.26 per quartile increase (95% CI, 1.09-1.45). Presence of steatosis on baseline biopsy was associated with an increased outcome rate among patients with bridging fibrosis (P < .0001) and a decreased rate among patients with cirrhosis (P = .006). Presence of Mallory bodies was associated with outcomes (HR, 1.59; 95% CI, 1.10-2.31) as was significant weight change of>>or=5% in the first year after randomization (HR, 1.25 per category increase in weight, 95% CI, 1.01-1.55).

CONCLUSIONS

Insulin resistance, histologic features of fatty liver disease, and weight change were associated with outcomes of chronic hepatitis C. Improvement in these weight-related factors might modify disease progression.

OBJECTIVE

We hypothesized that interaction between PPARG2 Pro12Ala and variants in the promoter region of HNF4A are associated with type 2 diabetes-related quantitative traits in Mexican-American families of a proband with previous gestational diabetes.

METHODS

The BetaGene project genotyped PPARG2 Pro12Ala and nine HNF4A single nucleotide polymorphisms (SNPs) in 473 individuals in 89 families. Members of the proband generation had fasting glucose <126 mg/dl and were phenotyped by oral and intravenous glucose tolerance tests.

RESULTS

Neither PPARG2 Pro12Ala nor any of the nine HNF4A SNPs were independently associated with type 2 diabetes-related quantitative traits. However, the interaction between PPARG2 Pro12Ala and HNF4A rs2144908 was significantly associated with both insulin sensitivity (S(I)) (Bonferroni P = 0.0006) and 2-h insulin (Bonferroni P = 0.039). Subjects with at least one PPARG2 Ala allele and homozygous for the HNF4A rs2144908 A allele had 40% higher S(I) compared with individuals with at least one G allele. S(I) did not vary by rs2144908 genotype among PPARG2 Pro/Pro. The interaction result for S(I) was replicated by the Insulin Resistance Atherosclerosis Family Study (P = 0.018) in their San Antonio sample (n = 484) where subjects with at least one PPARG2 Ala allele and homozygous for the HNF4A rs2144908 A allele had a 29% higher S(I) compared with individuals with at least one G allele. However, the interaction was not replicated in their San Luis Valley sample (n = 496; P = 0.401).

CONCLUSIONS

Together, these results suggest that variation in PPARG2 and HNF4A may interact to regulate insulin sensitivity in Mexican Americans at risk for type 2 diabetes.

OBJECTIVE

As Latinos are a growing ethnic group in the United States, it is important to understand the socio-cultural factors that may be associated with cancer screening and prevention in this population. The socio-cultural factors that may affect preparedness to undergo genetic cancer risk assessment (GCRA) deserve particular attention. The pre-GCRA period can provide insight into variables that may influence how medically underserved Latinas, with limited health resources and access, understand hereditary cancer information and subsequently implement cancer risk management recommendations. This study explores social, cognitive and cultural variables in Latinas prior to undergoing GCRA.

METHODS

The study sample consisted of low-income, underserved Latinas referred for GCRA because of a personal and/or family history of breast or ovarian cancer. Acculturation, cancer-specific fatalism, self-efficacy and social support were assessed prior to GCRA.

RESULTS

Fifty Latinas (mean age=40.1+/-7.7) completed instruments; 86% had invasive cancer, 78% spoke primarily Spanish and 61% were of Mexican ancestry. Low levels of acculturation (n=50, mean=9.0+/-5.8) and cancer-specific fatalism (n=43, mean=5.6+/-3.2), but relatively high self-efficacy (n=49, mean=40.9+/-7.8) and social support (n=49, mean=37.3+/-8.7) were reported. Cancer-specific fatalism and self-efficacy were inversely correlated (r=-0.47, p=0.002). Those over age 38 at the time of cancer diagnosis reported higher acculturation (mean=11.4+/-7.2, p=0.02) and social support (mean=40.5+/-1.2, p=0.05).

CONCLUSIONS

These findings suggest that medically underserved Latinas may already possess some of the necessary skills to successfully approach the GCRA process, but that special attention should be given to cultural factors.