Is bilateral lung transplantation in pulmonary artery hypertension related to congenital heart disease a real therapeutic option? Experience of a national referral centre

Background

Pulmonary arterial hypertension (PAH) affects almost 10% of patients with congenital heart disease, markedly worsening their prognosis. Bilateral lung or cardiopulmonary transplantation is therefore the last therapeutic option. The presence of underlying congenital heart disease (CHD) leads many of these patients directly to cardiopulmonary transplantation. However, this option is increasingly limited due to the shortage of organs and the high risk of the procedure.

Purpose

Demonstrate that isolated bilateral lung transplantation (BLT) associated with repair of simple heart defects is an option that leads to good prognostic outcomes and adequate positive cardiac chamber remodelling.

Methods

We retrospectively analysed the cases of PAH-CHD in our centre who underwent BLT from September 2010 to January 2022.

Results

During the recorded time 12 of the 135 PAH-CHD patients followed in our unit were considered for transplantation. Six BLT were finally performed. The reasons for rejecting the option of transplantation in patients with congenital heart disease included, in addition to the usual ones (age, histocompatibility, comorbidities, ...) the presence of abundant collateral circulation or repeated thoracic interventions. Of the 6 patients who underwent transplantation of both lungs, the mean age was 39±10 years and 4 were women (66.6%). All of them had previous symptoms of heart failure, 4 of them presented recurrent supraventricular arrhythmias requiring ablation, one of them required stent implantation in the left coronary trunk due to extrinsic compression by the pulmonary artery trunk and another had presented threatening haemoptysis requiring embolization of bronchial branches. Regarding the aetiology of PAH-CHD, two of the patients had residual PAH after previous closure of the intracardiac defect years earlier and the remaining four patients (66.6%) had an incidental intracardiac shunt (2 ASD and 2 VSD). Both incidental ASD were closed in the main intervention. The course of the operation and immediate post-transplantation was similar to other PAH transplants, with a mean ICU stay of 10 days. All patients were discharged home and remain alive to date without recurrence of cardiovascular symptoms. On post-transplant echocardiographic re-evaluation, all patients had normalized right chambers in terms of both size and function (Table 1).

Conclusion

Isolated bilateral lung transplantation is a real option for most cases of pulmonary arterial hypertension associated with congenital heart disease with simple or previously repaired defects. BLT in these patients is not accompanied by a higher rate of complications in the immediate postoperative period and in the long term means the resolution of cardiovascular symptoms with the adequate positive remodelling of the right chambers.

Funding Acknowledgement

Type of funding sources: None.

How Mechanical Forces Shape Plant Organs

Plants produce organs of various shapes and sizes. While much has been learned about genetic regulation of organogenesis, the integration of mechanics in the process is also gaining attention. Here, we consider the role of forces as instructive signals in organ morphogenesis. Turgor pressure is the primary cause of mechanical signals in developing organs. Because plant cells are glued to each other, mechanical signals act, in essence, at multiple scales, through cell wall contiguity and water flux. In turn, cells use such signals to resist mechanical stress, for instance, by reinforcing their cell walls. We show that the three elemental shapes behind plant organs - spheres, cylinders and lamina - can be actively maintained by such a mechanical feedback. Combinations of this 3-letter alphabet can generate more complex shapes. Furthermore, mechanical conflicts emerge at the boundary between domains exhibiting different growth rates or directions. These secondary mechanical signals contribute to three other organ shape features - folds, shape reproducibility and growth arrest. The further integration of mechanical signals with the molecular network offers many fruitful prospects for the scientific community, including the role of proprioception in organ shape robustness or the definition of cell and organ identities as a result of an interplay between biochemical and mechanical signals.

Beta-blockers in elderly patients with left ventricular systolic dysfunction and chronic kidney disease: danger or benefit?

Introduction

Beta-blockers (BB) have been shown to reduce mortality in patients with HFrEF. However, there is little data on the benefit of these therapies in patients with chronic kidney disease and even less in older patients. The aim of this work is to evaluate the role of beta-blockers in patients ≥75 years along the spectrum of kidney disease.

Methods

From January 2008 to July 2014, we consecutively enlisted 802 patients aged >75 years that had ejection fraction ≤35%. From this group we included 380 patients that had CKD (defined as a glomerular filtration rate (GFR) ≤60 ml/min/1.73m2). Clinical, echocardiographic and electrocardiographic data were taken from hospital records. Follow-up was made via telephone and hospital records as well. Propensity score matching analysis was made to assess the relationship between treatment with BB and occurrence of major adverse cardiovascular event (MACE) composite of death for any cause or heart failure. hospitalization. Multivariate Cox regression analysis was also made in the different groups of CKD (45–60 ml/min/1.73m2, 30–45 ml/min/1.73m2, <30 ml/min/1.73m2) in order to assess the effect of BB over mortality and CV events in each subgroup.

Results

390 patients were included. Male represented 62.3% of all participants, and the mean age was 82.6±4.1 years. The mean ejection fraction was 27.9±6.5%. Ischemic etiology was found in 50.6% of cases. Glomerular filtrate (GF) was 60 to 45 ml/min/1.73 m2 in 50.3% of patients, 45–30 ml/min/1.73 m2 in 37.4% and <30 ml/min/1.73 m2 in 12.3%. At the end of the follow-up, 67.4% of the patients were on beta-blocker treatment. The mean follow-up was 32±23 months. During the study period, 211 patients (54.1%) died and 257 patients (65.9%) had a major cardiovascular event (death or hospitalization for heart failure). After propensity score matching analysis, 178 were considered (89 each group) and they have no significant difference in baseline characteristics. BBs were found to significantly reduce mortality (HR 0.45 (95% CI, 0.27–0.75). When the effect of BB over the different subgroups of CKD was analyzed, it was seen also that BB reduced mortality in patients with eGFR 45–60 ml/min/1.73 m2 (HR 0.47 (95% CI, 0.26–0.86), in patients with eGFR 30–45 ml/min/1.73 m2 (HR 0.55 (95% CI, 0.26–1.06)and in eGFR <30 ml/min/1.73 m2 (HR 0.29 (95% CI, 0.11–0.76)

Conclusion

The use of beta-blockers in elderly patients with HFrEF and kidney DISEASE was associated with increased survival, regardless of the degree of kidney failure. There is a need to raise awareness of the benefits of beta-blocker use in these patients to promote their use where possible.

Funding Acknowledgement

Type of funding source: None

Paf1c defects challenge the robustness of flower meristem termination in Arabidopsis thaliana

Although accumulating evidence suggests that gene regulation is highly stochastic, genetic screens have successfully uncovered master developmental regulators, questioning the relationship between transcriptional noise and intrinsic robustness of development. To identify developmental modules that are more or less resilient to large-scale genetic perturbations, we used the Arabidopsis polymerase II-associated factor 1 complex (Paf1c) mutant vip3, which is impaired in several RNA polymerase II-dependent transcriptional processes. We found that the control of flower termination was not as robust as classically pictured. In angiosperms, the floral female organs, called carpels, display determinate growth: their development requires the arrest of stem cell maintenance. In vip3 mutant flowers, carpels displayed a highly variable morphology, with different degrees of indeterminacy defects up to wild-type size inflorescence emerging from carpels. This phenotype was associated with variable expression of two key regulators of flower termination and stem cell maintenance in flowers, WUSCHEL and AGAMOUS. The phenotype was also dependent on growth conditions. Together, these results highlight the surprisingly plastic nature of stem cell maintenance in plants and its dependence on Paf1c.

Summary: Using a mutant with increased transcriptional noise, we reveal that stem cell maintenance is not as robust as anticipated in plants, even leading to major defects in essential developmental processes such as flower indeterminacy.

P6251Prognostic value of ACEi/ARBS in elderly patients with heart failure with reduced ejection fraction with and without chronic kidney disease

Introduction

Angiotensin-converting enzyme inhibitors/ angiotensin receptor blockers therapy (ACEI/ARB) have shown to reduce mortality in patients with heart failure and reduced left ventricular ejection fraction (HFrEF). However, there is lack of information about the benefit of these drugs in patients with chronic kidney disease (CKD), and even less in elderly patients. Our aim is to compare the prognostic impact of ACE/ARB if CKD is present or not

Methods

From January 2008 to July 2014, we consecutively enlisted 802 patients aged >75 years that had ejection fraction ≤35%. Clinical, echocardiographic and ECG data were taken from hospital records. Follow-up was made via telephone and hospital records as well. We analyzed the relationship between treatment with ACEi/ARBs (with different doses) and occurrence of mortality or MACE (major adverse cardiovascular events: composite of death from any cause or hospitalization for heart failure).

Results

From the total population 410 (51%) patients that had not CKD (glomerular filtration rate (GFR) >60ml/min/1,73m2) and 390 (49%) patients had CKD (with GFR ≤60ml/min/1,73m2). We analyze the population according the presence or not of CKD. Both groups had similar characteristics except the age: 81.5±4.5 years vs. 82.6±4.1 (p<0.05) and the percentage of use of ACEi/ARB 78.8% of the total vs 66.9% of the total (p<0.05). The mean ejection fraction was 27.9±6.5% vs 28.12±6.5% (p>0.05). The mean follow up was 33±22 vs 32±23 months (p>0.05). In patients with no CKD 170 (42%) patients died and 239 (58%) patients had a MACE. In the CKD group 211 (54.1%)patients died and 257 (65.9%)patients had a major cardiovascular event. In the univariate analysis in both groups the use of ACEi/ARB reduced the mortality and the MACE. After a multivariate analysis ACEi/ARB appear to be beneficial in the CKD group (OR 0.71 [0.50–0.98]) but not in no CKD group

Conclusions

According to our data, treatment with ACEI/ARB in elderly patients HFrEF and CKD should be encouraged even more than in those without CKD.

P1579Impact of Renal Dysfunction on Real-world Outcome of the ESC 0/1-hour Algorithm

Background

The ESC recommends the use of a 0/1h-algorithm for rapid triage of patients with suspected non-ST-elevation myocardial infarction (NSTEMI) using high-sensitivity cardiac troponin (hs-cTn) concentrations irrespective of renal function. Patients with renal dysfunction (RD, defined as a GFR <60ml/min) are at higher risk of NSTEMI and are presenting more often with elevated levels of hs-cTn even in absence of NSTEMI, which may contribute to an impaired efficacy and safety of the ESC 0/1h-algorithm.

Purpose

We aimed to assess and directly compare the real-world adherence, effectiveness, efficacy, and ultimately safety of the ESC 0/1h-algorithm when applied in patients with RD and normal renal function.

Methods

In a prospective international multicenter study enrolling unselected patients presenting with suspected NSTEMI to the ED, patients were assessed according to the ESC 0/1h-algorithm embedded in routine clinical care. Safety was quantified by the 30-day incidence of major adverse cardiac events (MACE, defined as the composite of cardiovascular death and myocardial infarction including the index event) in the rule-out group and in outpatients.

Results

Among 2296 enrolled patients, RD was present in 129 (6%) patients. NSTEMI prevalence was substantially higher in RD as compared with normal renal function (19% versus 9%, p<0.001). Adherence to the ESC 0/1h-algorithm protocol was excellent with no violations observed in patients with RD as compared with 132 (6%) violations in patients with normal renal function (p=0.004). Effectiveness was very high in RD and comparable to normal renal function: 94% of patients triaged towards rule-out by the ESC 0/1h-algorithm did not require additional cardiac investigations including hs-cTnT measurements at later time points (e.g. 3–12h) or coronary CT-angiography in the ED as compared with 98% in normal renal function. Median time to discharge or transfer from the ED was significantly longer in RD (285 minutes [q1174, q3392]) as compared with normal renal function (150 minutes [q1132, q3222]). Efficacy of the ESC 0/1h-algorithm was lower in RD as it triaged 13% of patients towards rule-out and 34% towards rule-in of NSTEMI as compared with 65% and 12% in normal renal function, respectively (p<0.001). Overall, 30% of patients with RD underwent outpatient management as compared with 73% in normal renal function (p<0.001). Safety of rule-out and outpatient management were excellent in RD with a 30-day MACE incidence of both 0% and comparable with 0.2% and 0.1% in normal renal function, respectively (p=0.010).

Conclusions

These real-world data document for the first time the excellent adherence, effectiveness, and safety of the ESC 0/1h-algorithm when routinely applied in patients with RD. Compared with patients with normal renal function, fewer patients with RD could be triaged towards rule-out or were treated as outpatients, most likely due to the higher prevalence of NSTEMI and comorbidities in RD.

Equity-focused health impact assessment of Portuguese tobacco control legislation

The World Health Organization recommend the Equity-Focused Health Impact Assessment (HIA) as a means to assess the impact of social and economic policies on the health of populations, and acknowledges their contribution to health inequality. We describe the application of the Equity-focused Impact Assessment methodology on the Portuguese law on Smoking Prevention and Tobacco Control (Law No. 37/2007). A rapid assessment was carried out to issue recommendations which could be incorporated into the law during a revision in 2014. Quantitative (consumption and health status indicators; equity analysis) and qualitative (Focus Group) approaches were taken to evaluate the impact of the law and formulate recommendations. Young people, men and women of low socioeconomic status, and pregnant women were identified as requiring specific and appropriate interventions to prevent smoking and support smoking cessation.

RNAseq profiling of primary microglia and astrocyte cultures in near-term ovine fetus: A glial in vivo-in vitro multi-hit paradigm in large mammalian brain

BACKGROUND

The chronically instrumented fetal sheep is a widely used animal model to study fetal brain development in health and disease, but no methods exist yet to interrogate dedicated brain cell populations to identify their molecular and genomic phenotype. For example, the molecular mechanisms whereby microglia or astrocytes contribute to inflammation in the brain remain incompletely understood.

NEW METHOD

Here we present a protocol to derive primary pure microglial or astrocyte cultures from near-term fetal sheep brain, after the animals have been chronically instrumented and studied in vivo. Next, we present the implementation of whole transcriptome sequencing (RNAseq) pipeline to deeper elucidate the phenotype of such primary sheep brain glial cultures.

RESULTS

We validate the new primary cultures method for cell purity and test the function of the glial cells on protein (IL-1β) and transcriptome (RNAseq) levels in response to a lipopolysaccharide (LPS) challenge in vitro.

COMPARISON WITH EXISTING METHODS

This method represents the first implementation of pure microglial or astrocytes cultures in fetal sheep brain.

CONCLUSIONS

The presented approach opens new possibilities for testing not only supernatant protein levels in response to an in vitro challenge, but also to evaluate changes in the transcriptome of glial cells derived from a large mammalian brain bearing high resemblance to the human brain. Moreover, the presented approach lends itself to modeling the complex multi-hit paradigms of antenatal and perinatal cerebral insults in vivo and in vitro.

Improvement of quality of life in allergic rhinoconjunctivitis patients using nasal filters, a preliminary study

BACKGROUND

Allergic rhinoconjunctivitis is a clinical condition that impairs quality of life. The use of traditional drugs in many cases is not enough to improve quality of life in these patients.

METHODS

In this pilot study we used the Sanispira Nasal filters in 15 patients (mean age 34,7 years) affected by allergic rhinoconjunctivitis for 18 days. At each follow-up visit, patients were assessed with a specific quality of life questionnaire, a symptoms form and a drugs form that evaluates the use of antiallergic drugs in the last week. Patients sensitive to environmental allergens wore Sanispira nasal filters during the day, while patients sensitive to domestic allergens wore the device during the night.

RESULTS

Thirteen patients completed the study. We found an improvement significative (p=0,0241) of the total score of RQLQ of 23,10 points between baseline and 18 days ( total score at baseline prior to nasal filter insertion= 60,60, at 1 week = 42, 28, at 18 days= 34, 10). A significative improvement in the nasal symptoms domain between baseline and 18 days (in particular stuffy nose p=0,047; runny nose p=0,012; sneezing p=0,0021; ) and one item of practical problems domain, the need to repeatedly blow the nose(p=0,082). The total score of symptoms evaluated with the symptoms form improved significantly from baseline to 18 days. Total symptoms score at baseline was 9,7; at 1 week it was 8,1 and at 18 days it was 4,7. The improvement was statistically significant (p=0,0092). Three of the thirteen patients that completed the study eliminated completely the use of drugs during of the study.

CONCLUSIONS

The use of SANISPIRA ®, has shown encouraging results, with an improvement in the quality of life in Rhinoconjunctivitis patients specially an improvement in nasal and ocular symptoms.

Human hepatocyte transplantation in patients with hepatic failure awaiting a graft

BACKGROUND

Hepatocyte transplantation (HT) has the potential to become a promising treatment to temporarily support liver function in patients with liver failure.

METHODS

Two patients, who had already received a liver transplant (LT) in the past, with an end-stage liver disease due to recurrent hepatitis C virus cirrhosis, suffering acute-on-chronic liver failure while on the waiting list for an LT, received HT as a bridge to whole-organ retransplantation. After HT and during intensive care unit admission, blood tests and ammonia levels were determined every 12 and 24 h, respectively, before and after each hepatocyte infusion.

RESULTS

The present study describes monitoring of analytical and clinical parameters and improvement of liver function following HT. In both patients, we managed to lower the blood ammonia levels and clinically improve the degree of hepatic encephalopathy, thus serving as a bridge to liver retransplantation in 1 patient.

CONCLUSIONS

We believe that this therapy may be an alternative treatment in patients with chronic liver disease who suffer episodes of acute decompensation as a bridge to conventional LT.

Mortality on the waiting list for liver transplantation: management and prioritization criteria

The excellent outcomes of liver transplantation (OLT) have increased its demand and the size of the waiting list, resulting in a substantial mortality rate before OLT, which is a treatment failure owing to disease development. We have reviewed the medical literature on this theme, focusing on prioritization methods.

New alternatives to the treatment of acute liver failure

INTRODUCTION

Acute-on-chronic liver failure (ACLF) is defined as an acute deterioration of a chronic liver disease. The most effective treatment in these patients is orthotopic liver transplantation (OLT), which is highly limited by the donor shortage. The aim of this study was to increase the usefulness of hepatocyte transplantation (HT) as a bridge or alternative to OLT.

METHODS

During the last 2 years, we have performed HT in 3 patients with ACLF. The diagnosis was graft cirrhosis due to hepatitis C virus in 2 of them, who were already included on waiting lists for retransplantation, and the third, unknown alcoholic cirrhosis.

RESULTS

After the first HT infusion, we observed an improvement in the clinical condition in all patients, hyperammonemia, and a partial correction of the degree of encephalopathy; 1 patient was retransplanted 6 days after the first HT.

DISCUSSION

The main indications for HT are inborn errors of metabolism in children. Other indications especially in adults, are acute liver failure, ACLF in patients with end-stage-liver disease who are a waiting OLT, and acute liver failure after an hepatectomy. HT may be a new treatment to improve the clinical condition in patients awaiting OLT.

Systematic review and meta-analysis of randomised clinical trials on topical treatments for vernal keratoconjunctivitis

AIMS

The aim of this study was to assess the efficacy of currently available topical drugs for vernal keratoconjunctivitis (VKC) through a meta-analysis of randomised clinical trials (RCTs).

METHODS

Twenty-seven RCTs (n = 2184 eyes) that had evaluated the efficacy of topical drugs for the treatment of VKC were selected according to the set criteria; 10 of these trials were suitable for statistical analysis and were enrolled in the meta-analysis. Articles published up to December 2005 were identified from the following

DATA SOURCES

Medline, Embase, Lilacs, the Cochrane Controlled Trials Register, and references from relevant articles. Articles in any language published with an English abstract, were screened, and those selected for inclusion were written in English, French, German, Italian, Portuguese or Spanish. The quality of the trials was assessed by the Delphi list. Statistical analysis was performed using STATA software.

RESULTS

A significant improvement in all signs and symptoms, except photophobia, was observed after topical treatment for active VKC, independent of the type of treatment. Comparison of the efficacy of different drugs was not possible due to a lack of standardised criteria among studies.

CONCLUSION

The currently available topical drugs are effective in treating acute phases of VKC. However, there is a lack of evidence to support the recommendation of one specific type of medication for treating this disorder. There is a need for standard criteria to assess diagnosis and therapy based on severity. There is also a need for RCTs assessing long-term effects of single drugs to control the disease and to prevent complications.

LMO4 can interact with Smad proteins and modulate transforming growth factor-beta signaling in epithelial cells

LIM-only protein 4 (LMO4) plays critical roles in mammalian development, and has been proposed to play roles in epithelial oncogenesis, including breast cancer. As LMO4 is highly expressed in the epithelial compartments at locations of active mesenchymal-epithelial interactions, we reasoned that LMO4 might act by modulating signaling pathways involved in mesenchymal-epithelial signaling. One such candidate signal is the transforming growth factor-beta (TGFbeta) cytokine pathway, which plays important roles both in development and cancer. We show here that the transcriptional response to TGFbeta in epithelial cells is sensitive to LMO4 levels; both up- and downregulation of LMO4 can enhance TGFbeta signaling as assessed by a TGFbeta-responsive reporter gene. Furthermore, LMO4 can interact with the MH1 and linker domains of receptor-mediated Smad proteins, and associate with the endogenous TGFbeta-responsive Plasminogen Activator Inhibitor-1 gene promoter in a TGFbeta-dependent manner, suggesting that such interactions may mediate the effects of LMO4 on TGFbeta signaling. When introduced into mammary epithelial cells, LMO4 potentiated the growth-inhibitory effects of TGFbeta in those cells. These results define a new function for LMO4 as a coactivator in TGFbeta signaling, and provide a potential novel mechanism for LMO4-mediated regulation in development and oncogenesis.

Upregulation of ICAM-1 expression in the conjunctiva of patients with chronic graft-versus-host disease

PURPOSE

To correlate conjunctival intercellular adhesion molecule 1 (ICAM-1) expression with cytologic and clinical findings of chronic graft-versus-host disease (GVHD).

METHODS

Seven patients with chronic GVHD-related keratoconjunctivitis and five age-matched normal controls were recruited for the study. Clinical examination included medical history, visual acuity, evaluation of ocular signs and symptoms (scored from 0 to 3), corneal fluorescein staining (scored from 0 to 5 on the basis of the number of corneal sectors involved), Schirmer test type I, and break-up time (BUT). Impression cytology samples were collected from the nasal and inferior bulbar conjunctiva of patients and controls. Goblet cells were counted in three randomly selected fields and averaged. Immunofluorescent staining for ICAM-1 was carried out and the percentage of cells expressing the marker was evaluated.

RESULTS

All patients showed signs and symptoms of keratoconjunctivitis sicca. Schirmer test type I and BUT were reduced (4.8+/-6.7 mm/5 min and 3.9+/-2.7 seconds, respectively). Goblet cells were significantly reduced in GVHD eyes with respect to normal eyes (65+/-30.5 and 192+/-16.9 cells/field respectively; p<0.001). Goblet cell number was directly related to Schirmer test values (p<0.01, rho=0.817) and inversely related to total sign score (p<0.01, rho=-0.939). ICAM-1 expression was increased in GVHD eyes with respect to normal controls, in which no staining was observed. ICAM-1 expression showed an inverse relation to goblet cell number (p<0.01, rho=-0.852) and Schirmer test values (p<0.01, rho=-0.926), and was directly correlated to total sign score (p<0.01, rho=0.982).

CONCLUSIONS

Conjunctival ICAM-1 expression is increased in GVHD patients. The severity of the disease is associated with tear parameters, goblet cell decrease, and inflammatory markers, such as ICAM-1.

Antileishmanial activity of polycyclic derivatives

33 polycyclic derivatives have been studied and tested on Leishmania donovani and L. major promastigotes. Their antileishmanial activity was assessed in vitro and an assay of their cytotoxicity was realized on human myelomonocytic cell line. The reference molecules used in the assays were amphotericin B and pentamidine. Among the compounds tested, 29 possess an antileishmanial activity; 25 of those were more active against L. donovani than amphotericin B, and nine were as effective as amphotericin B against L. major. Many synthesized derivatives were more active against L. donovani than against L. major. The cytotoxicity studies have shown that among the thirty-three derivatives tested, 12 molecules have an IC50 towards THP-1 cells about equal than that reference drugs, the 21 other derivatives are much less toxic. A 3D QSAR study was undertaken and has permitted to predict activity against L. donovani and L. major and to highlight critical area to optimize activity against the two species.

Genetic variation in the vulnerable and endemic Monkey Puzzle tree, detected using RAPDs

Araucaria araucana (Monkey Puzzle), a southern South American tree species of exceptional cultural and economic importance, is of conservation concern owing to extensive historical clearance and current human pressures. Random amplified polymorphic DNA (RAPD) markers were used to characterise genetic heterogeneity within and among 13 populations of this species from throughout its natural range. Extensive genetic variability was detected and partitioned by analysis of molecular variance, with the majority of variation existing within populations (87.2%), but significant differentiation was recorded among populations (12.8%). Estimates of Shannon's genetic diversity and percent polymorphism were relatively high for all populations and provide no evidence for a major reduction in genetic diversity from historical events, such as glaciation. All pairwise genetic distance values derived from analysis of molecular variance (Phi(ST)) were significant when individual pairs of populations were compared. Although populations are geographically divided into Chilean Coastal, Chilean Andes and Argentinean regions, this grouping explained only 1.77% of the total variation. Within Andean groups there was evidence of a trend of genetic distance with increasing latitude, and clustering of populations across the Andes, suggesting postglacial migration routes from multiple refugia. Implications of these results for the conservation and use of the genetic resource of this species are discussed.

The validity of self-reported seatbelt use: Hispanic and non-Hispanic drivers in El Paso

The validity of self-reported seatbelt use among low belt use populations has not been evaluated directly, despite the importance of such data for estimating the effectiveness of community-wide interventions and compliance with state laws. To address this gap in knowledge 612 drivers were recruited from convenience stores located in 12 randomly generated zip code areas located in El Paso, TX. Self-reported seatbelt use was compared with observed seatbelt use in a single sample of participants. Both data sets were collected almost contemporaneously and no participant was aware of having their seatbelt use observed. Hispanic (n = 388) and white/non-Hispanic (n = 126) drivers over reported seatbelt use by 27 and 21%, respectively. These findings suggest that response bias within low belt use populations may be greater than suggested by state and national data.

Control of lymphocyte development by the Ikaros gene family

Lymphoid cell differentiation relies on precisely orchestrated gene activation and repression events. Gene targeting studies have demonstrated crucial roles for the transcription factors Ikaros and Aiolos in regulating multiple stages of B and T cell development. Recent experiments suggest that Ikaros and Aiolos set B cell antigen-receptor (BCR)- and TCR-mediated signaling thresholds and that the molecules exist within T cells in nuclear complexes that contain nucleosome remodeling and histone deacetylase activities.

Seatbelt use and belief in destiny among Hispanic and non-Hispanic drivers

In order to determine if fatalism is associated with seatbelt use, 312 drivers were recruited from convenience stores located within 12 randomly generated zip-code areas along the Texas-Mexico border. The seatbelt use of drivers was recorded unobtrusively; self-reported seatbelt use and belief in destiny (fatalism) were subsequently obtained by interview. The majority of respondents rejected a fatalistic orientation, although Hispanic drivers were significantly less likely to do so. Fatalism was not associated with observed seatbelt use. Our results suggest that ethnic differences in seatbelt use are not due to ethnic differences in fatalism. These findings have implications for developing health interventions in Hispanic and non-Hispanic communities.

ETS-core binding factor: a common composite motif in antigen receptor gene enhancers

A tripartite domain of the murine immunoglobulin mu heavy-chain enhancer contains the muA and muB elements that bind ETS proteins and the muE3 element that binds leucine zipper-containing basic helix-loop-helix (bHLH-zip) factors. Analysis of the corresponding region of the human mu enhancer revealed high conservation of the muA and muB motifs but a striking absence of the muE3 element. Instead of bHLH-zip proteins, we found that the human enhancer bound core binding factor (CBF) between the muA and mu elements; CBF binding was shown to be a common feature of both murine and human enhancers. Furthermore, mutant enhancers that bound prototypic bHLH-zip proteins but not CBF did not activate transcription in B cells, and conversely, CBF transactivated the murine enhancer in nonlymphoid cells. Taking these data together with the earlier analysis of T-cell-specific enhancers, we propose that ETS-CBF is a common composite element in the regulation of antigen receptor genes. In addition, these studies identify the first B-cell target of CBF, a protein that has been implicated in the development of childhood pre-B-cell leukemias.