Longitudinal profiling identifies co-occurring BRCA1/2 reversions, TP53BP1, RIF1 and PAXIP1 mutations in PARP inhibitor-resistant advanced breast cancer

BACKGROUND

Resistance to therapies that target homologous recombination deficiency (HRD) in breast cancer limits their overall effectiveness. Multiple, preclinically validated, mechanisms of resistance have been proposed, but their existence and relative frequency in clinical disease are unclear, as is how to target resistance.

PATIENTS AND METHODS

Longitudinal mutation and methylation profiling of circulating tumour (ct)DNA was carried out in 47 patients with metastatic BRCA1-, BRCA2- or PALB2-mutant breast cancer treated with HRD-targeted therapy who developed progressive disease-18 patients had primary resistance and 29 exhibited response followed by resistance. ctDNA isolated at multiple time points in the patient treatment course (before, on-treatment and at progression) was sequenced using a novel >750-gene intron/exon targeted sequencing panel. Where available, matched tumour biopsies were whole exome and RNA sequenced and also used to assess nuclear RAD51.

RESULTS

BRCA1/2 reversion mutations were present in 60% of patients and were the most prevalent form of resistance. In 10 cases, reversions were detected in ctDNA before clinical progression. Two new reversion-based mechanisms were identified: (i) intragenic BRCA1/2 deletions with intronic breakpoints; and (ii) intragenic BRCA1/2 secondary mutations that formed novel splice acceptor sites, the latter being confirmed by in vitro minigene reporter assays. When seen before commencing subsequent treatment, reversions were associated with significantly shorter time to progression. Tumours with reversions retained HRD mutational signatures but had functional homologous recombination based on RAD51 status. Although less frequent than reversions, nonreversion mechanisms [loss-of-function (LoF) mutations in TP53BP1, RIF1 or PAXIP1] were evident in patients with acquired resistance and occasionally coexisted with reversions, challenging the notion that singular resistance mechanisms emerge in each patient.

CONCLUSIONS

These observations map the prevalence of candidate drivers of resistance across time in a clinical setting, information with implications for clinical management and trial design in HRD breast cancers.

Blood pressure reduction in higher cardiovascular risk patients in the Global SYMPLICITY Registry

Background/Introduction

The Global SYMPLICITY Registry (GSR) was designed to evaluate the safety and efficacy of renal denervation (RDN) in real-world patients. Inclusion and exclusion criteria are limited to allow assessment of the effects of RDN on patients with a wide range of comorbidities. The current analysis examines blood pressure (BP) reduction after RDN in higher cardiovascular risk patients.

Purpose

To evaluate blood pressure reduction after RDN in higher cardiovascular risk patients in GSR.

Methods

GSR is a prospective all-comers registry to evaluate the safety and efficacy of RDN. Patients are enrolled in GSR and receive radiofrequency RDN using the Symplicity Flex or Symplicity Spyral catheter. Office and ambulatory BP are measured at each follow-up (3, 6, 12, 24, and 36 months). In this post-hoc analysis, changes from baseline in office and 24-hour ambulatory systolic blood pressure were assessed in patients at higher cardiovascular risk. Higher risk was defined using baseline office systolic or diastolic BP as well as additional risk factors (Figure 1).

Results

As of March 2021, there were 2621 patients characterized as higher cardiovascular risk in GSR. Baseline characteristics included mean age 60.7±12.1 years, 57.6% male, 37.9% type 2 diabetes, 35.8% hypocholesterolemia, 19.7% eGFR <60 mL/min/1.73 m2, 16.2% left ventricular hypertrophy, 10.2% previous stroke and 9.3% previous myocardial infarction. Baseline office systolic BP (OSBP) was 168.8±22.7 mmHg and baseline ambulatory systolic BP (ASBP) 155.3±18.6 mmHg. Mean OSBP reductions after RDN in this higher risk population ranged from −13.1 mmHg at 3 months to −17.5 mmHg at 24 months and −18.9 mmHg at 36 months, and mean ASBP reductions ranged from −7.8 mmHg at 3 months to −9.8 mmHg at 24 months and −9.3 mmHg at 36 months (Figure).

Conclusions

Higher risk patients in GSR had sustained office and ambulatory systolic BP reductions out to 3 years after catheter-based radiofrequency RDN.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic

Impact of coronary atherosclerotic plaque metrics and CT reader skills on inter-observer variation of repeated on-site CT-FFR

Funding Acknowledgements

Type of funding sources: None.

Background and Purpose

 

Little is known about the on-site CT-FFR inter-reader reproducibility and its variability in different atherosclerotic plaque scenarios. The aim of this study was to determine the variation of repeated CT-FFR analyses between two CCTA readers with different training skills across different atherosclerotic features. 

Methods

 

Patients referred for invasive coronary angiography who accepted to undergo a CCTA/CT-FFR study were prospectively included. Patients with contraindications for CCTA, atrial fibrillation, chronic total occlusions or previous coronary revascularization were excluded. Quantification of atherosclerotic plaque metrics and CT-FFR was performed for each coronary vessel by two different CT readers, one Level I and one Level III. Inter-reader agreement for CT-FFR was assessed using kappa index, Bland-Altman and Lin’s concordance correlation agreement (LCCA). The impact of each atherosclerotic feature was assessed by dividing the dataset based on the corresponding median and assessing inter-reader variability for both the lower and upper half.

Results

47 patients (137 vessels) were included. Mean age was 66 ± 10 years, 89% were males, 63% had hypertension, 76% dyslipidemia and 38% diabetes. Degree of stenosis was moderate (50-69%) in 29% and severe (≥70%) in 28% of vessels with a positive CT-FFR (≤0.80) in 39%. CT-FFR showed good correlation between the two readers based on a kappa index of 0.77 with a mean CT-FFR difference of -0.017 ± 0.12. The inter-reader agreement was good in the main epicardial vessels (LCCA of 0.70 for LAD, 0.74 for LCX and 0.76 for RCA, p < 0.001 for all) and better in proximal than in distal segments (LCCA of 0.83 vs 0.63, p < 0.001). Likewise, in different atherosclerotic plaque scenarios, the agreement was better in those vessels with lower plaque volume, less calcified and longer lesions (see table 1). 

Conclusions

 

In our cohort, on-site CT-FFR showed good inter-reader agreement without relevant impact by reader experience level and atherosclerotic plaque features.

Table 1 Mean difference Bland-Altman Lin’s concordance correlation coefficient p value Plaque volume < median (556 mm3) -0.01 ± 0.12 0.85 <0.001 Plaque volume > median (556 mm3) -0.035 ± 0.13 0.64 <0.001 Calcified plaque burden < median (34%) -0.03 ± 0.11 0.82 <0.001 Calcified plaque burden > median (34%) -0.02 ± 0.14 0.75 <0.001 Lesion length < median (55 mm) -0.005 ± 0.12 0.68 <0.001 Lesion length > median (55 mm) -0.031 ± 0.12 0.83 <0.001 *p values indicate inter-reader agreement by two independent observers for each category

P6174On-site CT-derived FFR predicts the need for revascularization

Background and purpose

Coronary computed tomography angiography (CTA) in combination with CT-derived fractional flow reserve (CT-FFR) is a solid tool for assessing both the anatomical and functional impact of coronary atherosclerotic disease (CAD) in a single study. The development of new software for on-site CT-FFR quantification may reduce costs and increase availability. The aim of this study was to analyze the incremental value of CT-FFR over CTA alone and its ability to predict the need for revascularization.

Methods

Patients referred for invasive coronary angiography (ICA) who accepted to undergo a CTA/CT-FFR study were prospectively included. Patients with any contraindication for CT, atrial fibrillation, chronic total occlusions, severe ventricular hypertrophy or previous coronary revascularization were excluded. On-site CT-FFR was calculated for each coronary vessel. Invasive FFR was quantified during ICA, considering ≤0.8 as a surrogate for the need for revascularization.

Results

33 patients (90 vessels) were included. Mean age was 65±10 years, 88% were males, 60% had hypertension, 77% dyslipidaemia and 40% diabetes. The average analysis time of CT-FFR was 16±4 minutes. There was a good correlation between CT-FFR and FFR in all three main epicardial vessels as well as in proximal segments or in moderate to severe stenosis (see Table). 83% of vessels with FFR≤0.8 were predicted by CT-FFR study (89% of LAD lesions, 86% of LCX and 66% of RCA). CT-FFR added incremental diagnostic value over CTA alone to predict FFR≤0.8 (ΔAUC 0.0336 with a net reclassification index 1.4±0.23; p<0.001) (see Image).

n Mean difference from Bland-Altman Pearson's r coefficient p value All-vessels 90 0.037±0.1 0.8 <0.001 Lesions in LAD 40 0.005±0.11 0.81 <0.001 Lesions in LCX 32 0.061±0.094 0.85 <0.001 Lesions in RCA 18 0.06±0.11 0.83 <0.001 Moderate lesions (50–69% QCA stenosis) 24 0.02±0.06 0.88 <0.001 Severe lesions (70–99% QCA stenosis) 25 0.034±0.18 0.4 <0.001 Proximal lesions 42 0.012±0.11 0.84 <0.001 Non-proximal lesions 48 0.061±0.1 0.78 <0.001

Conclusions

On-site CT-FFR is a good predictor of the need for revascularization in all three main coronary vessels and adds incremental diagnostic value over CTA alone. There is higher dispersion of the values in severe stenosis, lesions in LCX or RCA although this do not result in misclassification.

P6185Impact of coronary atherosclerotic plaque metrics on the correlation between on-site CT-FFR and invasive FFR

Background

Developed in the last years, coronary computed tomography-derived fractional flow reserve (CT-FFR) has shown good correlation with invasive fractional flow reserve (FFR). However, little is known about the interaction of coronary atherosclerotic plaque characteristics in the correlation between CT-FFR and FFR.

Purpose

This study sought to determine the effect of main coronary atherosclerotic plaque metrics (APM) on the correlation between on-site CT-FFR and invasive FFR.

Methods

Patients referred for invasive coronary angiography (ICA) who accepted to undergo a CT-FFR study were prospectively included. We excluded patients with atrial fibrillation, chronic total occlusions, severe ventricular hypertrophy or previous coronary revascularization, and those with any contraindication for CT. On-site CT-FFR and APM were calculated for each coronary vessel. Continuous variables of APM were dichotomized as above and below the median and their interaction on the correlation between on-site CT-FFR and invasive FFR was assessed by multiple linear regression model.

Results

33 patients (90 vessels) were included. Mean age was 65±10 years, 88% were males, 60% had hypertension, 77% dyslipidaemia and 40% diabetes. The mean delay time between CTA and ICA of 21 days. The average analysis time of CT-FFR was 16±4 minutes. Overall, correlation between FFR and CT-FFR showed a Pearson's r coefficient of 0.77±0.06 and a standardized beta coefficient of 0.8 (p<0.001). The beta coefficients between CT-FFR and FFR did not change significantly after the interaction with different APM (p>0.05 for all) (see Table).

Standardized Beta coefficients for on-site CT-FFR with invasive FFR as a gold standard Below the median Above the median p value for interaction Total atheroma volume (TAV) (mm3) 0.66 0.93 0.071 Percent atheroma volume (PAV) (%) 1.00 0.69 0.063 Calcified atheroma plaque volume (%) 0.89 0.68 0.175 Remodeling index 0.94 0.71 0.129 Lesion length (LL) (mm) 0.67 0.89 0.158 Minimal lumen area (mm2) 0.73 0.71 0.955

Conclusions

There is a good correlation between on-site CT-FFR and invasive FFR, which is not affected by main atherosclerotic plaque characteristics.

Autologous dental pulp mesenchymal stem cells for inferior third molar post-extraction socket healing: A split-mouth randomised clinical trial

Background

Since the discovery of adult mesenchymal stem cells extensive research has been conducted to determine their mechanisms of differentiation and effectiveness in cell therapy and regenerative medicine.

Material and Methods

To assess the efficacy of autologous dental pulp mesenchymal stem cells delivered in a collagen matrix for post-extraction socket healing, a single-centre, double-blind, randomised, split-mouth, controlled clinical trial was performed. Both impacted mandibular third molars were extracted from 32 patients. Dental pulp was collected and dissociated; the resulting cell suspension, obtained by centrifugation, was incorporated into a resorbable collagen matrix and implanted in 32 experimental post-extraction sockets. Collagen matrices alone were implanted in 32 contralateral, control post-extraction sockets. Two neuroradiologists independently assessed the extent of bone repair at 6 months after the extractions. Computed tomography (CT, Philips Brilliance) and an advanced display platform (IntelliSpace Portal) was used to record extraction socket density, expressed as Hounsfield units (HU) and height (mm) of the distal interdental bone septum of the second molar. Measurements at 6 months post-extraction were compared with measurements obtained immediately after extraction. Data were analysed with the statistical program STATA 14.

Results

Two patients dropped out of the study. The final sample consisted of 22 women and 8 men (mean age, 23 years; range: 18–30 years). Clinical, radiological, and surgical characteristics of impacted third molars of the control and experimental groups were homogeneous. Measurements obtained by the two neuroradiologists showed agreement. No significant differences were found in the extent of bone repair during analyses of density (p=0.4203 neuroradiologist 1; p=0.2525 neuroradiologist 2) or interdental septum height (p=0.2280 neuroradiologist 1; p=0.4784 neuroradiologist 2).

Conclusions

In our clinical trial, we were unable to demonstrate that autologous dental pulp mesenchymal stem cells reduce socket bone resorption after inferior third molar extraction.

Key words:Clinical trial, autologous, pulpal stem cells, extraction socket healing.

Electron Beam Irradiation Treatment of Cantaloupes: Effect on Product Quality

Despite the impressive advances in electron beam irradiation, the technology is not ready for application to all types of fresh and/or minimally processed fruits and vegetables. The relationships between food product quality (nutrients, colour and texture) and irradiation dose are still needed. Cantaloupes ( Cucumis melo, L.) have become a product of interest due to the recent food-borne illness outbreaks related to their consumption in the United States and other countries. The main goal of this study was to verify whether treatment of cantaloupes using electron beam technology has any detrimental effects on the product quality. Whole and fresh-cut packaged cantaloupes were irradiated using a linear electron beam accelerator with the single beam (10MeV) fixture. Samples were stored at 10°C for zero, 4, 8 and 12 days along with control (non-irradiated) samples and tested for colour, texture (firmness), size (density), sugars and carotene content to determine the effect of irradiation dose level (1.0, 1.5 and 3.1kGy). Results indicated that irradiation of cantaloupes, as whole fruits with dose up to 1.0kGy, caused no significant changes on the fruit’s physical and nutritional quality attributes. Irradiating at higher doses had an undesirable effect on product quality. The fresh-cut packaged cantaloupe may be irradiated up to 1.5kGy without worsening the product quality attributes. In both cases, carotene content slightly increased as irradiation dose increased. In general, samples irradiated with dose levels between 1.0-1.5kGy had better quality attributes than the non-irradiated samples.

Sorption of indium (III) onto carbon nanotubes

Indium has numerous applications in different industrial sectors and is not an abundant element. Therefore appropriate technology to recover this element from various process wastes is needed. This research reports high adsorption capacity of multiwalled carbon nanotubes (MWCNT) for In(III). The effects of pH, kinetics, isotherms and adsorption mechanism of MWCNT on In(III) adsorption were investigated and discussed in detail. The pH increases improves the adsorption capacity for In(III). The Langmuir adsorption model is the best fit with the experimental data. For the kinetic study, the adsorption onto MWCNT could be fitted to pseudo second-order. The adsorption of indium(III) can be described to a mechanism which consists of a film diffusion controlled process. Metal desorption can be achieved with acidic solutions.

[Computerized ranking test in three French universities: Staff experience and students' feedback]

BACKGROUND

The year 2016 will be pivotal for the evaluation of French medical students with the introduction of the first computerized National Ranking Test (ECNi). The SIDES, online electronic system for medical student evaluation, was created for this purpose. All the universities have already organized faculty exams but few a joint computerized ranking test at several universities simultaneously. We report our experience on the organization of a mock ECNi by universities Paris Descartes, Paris Diderot and Paris 13.

METHODS

Docimological, administrative and technical working groups were created to organize this ECNi. Students in their fifth year of medical studies, who will be the first students to sit for the official ECNi in 2016, were invited to attend this mock exam that represented more than 50% of what will be proposed in 2016. A final electronic questionnaire allowed a docimological and organizational evaluation by students. An analysis of ratings and rankings and their distribution on a 1000-point scale were performed.

RESULTS

Sixty-four percent of enrolled students (i.e., 654) attended the three half-day exams. No difference in total score and ranking between the three universities was observed. Students' feedback was extremely positive. Normalized over 1000 points, 99% of students were scored on 300 points only. Progressive clinical cases were the most discriminating test.

CONCLUSION

The organization of a mock ECNi involving multiple universities was a docimological and technical success but required an important administrative, technical and teaching investment.

Association of genetic variants of membrane receptors related to recognition and induction of immune response with Helicobacter pylori infection in Ecuadorian individuals

Helicobacter pylori (Hp) has a worldwide distribution showing its higher prevalence of infection in developing countries. Toll-like receptors (TLRs) and C-type lectin receptors (CLRs) are proteins that recognize pathogen-associated molecular patterns (PAMPs) and initiate an innate immune response by promoting growth and differentiation of specialized hematopoietic cells for host defense. Gastric infections led by Hp induce a Th-1 cellular immune response, regulated mainly by the expression of IFN-γ. In this retrospective case-control study, we evaluated the TLR1 1805T/G, TLR2 2029C/T, TLR4 896A/G, CD209 -336A/G and IFNGR1 -56C/T polymorphisms and their relationship with susceptibility to Hp infection. TLR1 1805T/G showed statistical differences when the control (Hp-) and infected (Hp+) groups (P = 0.041*) were compared; the TLR1 1805G allele had a protective effect towards infection (OR = 0.1; 95% CI = 0.01-0.88, P = 0.033*). Similarly, the IFNGR1 -56C/T polymorphism showed statistical differences between Hp+ and Hp- (P = 0.018*), and the IFNGR1 -56TT genotype exhibited significant risk to Hp infection (OR = 2.9, 95% CI = 1.27-6.54, P = 0.018*). In conclusion, the pro-inflammatory TLR1 1805T and IFNGR1 -56T alleles are related with susceptibility to Hp infection in Ecuadorian individuals. The presence of these polymorphisms in individuals with chronic infection increases the risk of cellular damage and diminishes the cellular immune response efficiency towards colonizing agents.

Barrier Layer Morphological Stability and Adhesion to Porous Low-κ Dielectrics

Two particularly important reliability issues facing the integration of low- κ dielectric films are the fracture energy of the barrier-dielectric interface and the barrier layer integrity during processing. We have noticed that the compressive stresses in the barrier layers on low- κ dielectrics lead to spontaneous delamination and formation of telephone-cord like morphologies. These morphologies allow the measurement of fracture energy and are advantageous over artificially contrived features to yield realistic debonding parameters. The fracture energy of common barrier films, TaN and Ta, was determined using this method for varying porosity nanoporous silica and MSQ. Detailed characterization of the telephone cord morphology using a combination of Optical Microscopy, SEM and Profilometry was done. The fracture energy for Ta on different low-κ dielectrics was evaluated using a 1-D model for straight buckles. The kinetic coefficient of buckling was also evaluated.

Optimal dose and timing in phytohaemagglutinin skin-testing of deer

AIM

To establish the optimal dose of the mitogen phytohaemagglutinin (PHA) and the optimal time for measuring increased skin-fold thickness in red deer following intradermal injection, as an indicator of cell-mediated immune response.

METHODS

Three doses (10, 50 and 250 microg) of PHA were injected intradermally in the right side of the neck, and phosphate buffered saline (PBS) was injected at a fourth site as a control, in 20 captive Iberian red deer (Cervus elaphus hispanicus) hinds. Skin-fold thicknesses were measured at 0, 12, 24, 36, 48, 60, 72, 84 and 96 h following injection.

RESULTS

The highest dose of PHA tested (250 microg) resulted in a clear and long-lasting cellular response; increases in skin-fold thickness between 48 and 84 h post-injection varied minimally and response correlated positively with liveweight. No correlations with liveweight and no clear increases in skin-fold thickness occurred at the lower doses of PHA or the PBS.

CONCLUSIONS AND CLINICAL RELEVANCE

This technique could be applied with minimal training and without specialised equipment in deer, for immunological and ecological research.

Effect of Dielectric Pore Size Distribution on Interfacial Adhesion of the Tantalum-Porous Dielectric Interface

In this work we report the adhesion of a thin Tantalum (Ta) barrier films deposited on nanoporous dielectric substrates (Xerogel and Methyl Silesquioxanes (MSQ)). The high compressive stresses in the Ta barrier layer lead to spontaneous delamination from the underlying substrate resulting in a telephone cord like morphology, which allows the measurement of critical interfacial adhesion (fracture) energy. The fracture energy of Ta barrier films on different porous substrates is evaluated using the above two methods and the resulting differences are explained. Fracture energy varies inversely as a power law with the dielectric pore size indicating pores are essential to delamination in the barrier-dielectric interface. The observed trend of fracture energy is related to other mechanical properties of the porous substrate offering insights into the underlying mechanisms governing fracture of films deposited on porous substrates.

Pulmonary imaging of pandemic influenza H1N1 infection: relationship between clinical presentation and disease burden on chest radiography and CT

The potential for pulmonary involvement among patients presenting with novel swine-origin influenza A (H1N1) is high. To investigate the utility of chest imaging in this setting, we correlated clinical presentation with chest radiographic and CT findings in patients with proven H1N1 cases. Subjects included all patients presenting with laboratory-confirmed H1N1 between 1 May and 10 September 2009 to one of three urban hospitals. Clinical information was gathered retrospectively, including symptoms, possible risk factors, treatment and hospital survival. Imaging studies were re-read for study purposes, and CXR findings compared with CT scans when available. During the study period, 157 patients presented with subsequently proven H1N1 infection. Hospital admission was necessary for 94 (60%) patients, 16 (10%) were admitted to intensive care and 6 (4%) died. An initial CXR, carried out for 123 (78%) patients, was abnormal in only 40 (33%) cases. Factors associated with increased likelihood for radiographic lung abnormalities were dyspnoea (p<0.001), hypoxaemia (p<0.001) and diabetes mellitus (p = 0.023). Chest CT was performed in 21 patients, and 19 (90%) showed consolidation, ground-glass opacity, nodules or a combination of these findings. 4 of 21 patients had negative CXR and positive CT. Compared with CT, plain CXR was less sensitive in detecting H1N1 pulmonary disease among immunocompromised hosts than in other patients (p = 0.0072). A normal CXR is common among patients presenting to the hospital for H1N1-related symptoms without evidence of respiratory difficulties. The CXR may significantly underestimate lung involvement in the setting of immunosuppression.

Feeding behaviour of Belminus ferroae (Hemiptera: Reduviidae), a predaceous Triatominae colonizing rural houses in Norte de Santander, Colombia

Belminus ferroae (Hemiptera: Reduviidae) was collected from houses in the localities of San Alberto and Santa Catalina in the municipality of Toledo, Department of Norte de Santander, Colombia. Precipitin tests revealed that the main hosts of B. ferroae are insects belonging to the order Blattodea, whose haemolymph serves as food (89.43%). A low rate of haematophagy was indicated on rodents, dogs and humans (7.32%) and no natural infection with Trypanosoma cruzi was found by either microscopic examination or polymerase chain reaction. The finding of B. ferroae inside houses, feeding primarily on Blattodea with only a minor tendency to feed on vertebrate blood, is indicative of both the evolutionary path from predator to blood-sucker taken by Triatominae and their tendency to adapt from silvatic to domestic habitats.

Long‐term accumulation and microdistribution of uranium in the bone and marrow of beagle dog

The accumulation and microdistribution of uranium in the bone and marrow of Beagle dogs were determined by both neutron activation and neutron-fission analysis. The experiment started immediately after the weaning period, lasting till maturity. Two animal groups were fed daily with uranyl nitrate at concentrations of 20 and 100 microg g(-1) food. Of the two measuring techniques, uranium accumulated along the marrow as much as in the bone, contrary to the results obtained with single, acute doses. The role played by this finding for the evaluation of radiobiological long-term risks is discussed. It was demonstrated, by means of a biokinetical approach, that the long-term accumulation of uranium in bone and marrow could be described by a piling up of single dose daily incorporation.

The effects of sex and age on phytohaemagglutinin skin-testing of deer

AIM

To determine if there are sex- or age-related differences in the increase in skinfold thickness in response to the mitogen phytohaemagglutinin (PHA) in red deer.

METHODS

One dose of 250 mug PHA was injected intradermally in the right side of the neck, and phosphate buffered saline (PBS) was injected at a second site as a control, in 110 (51 males and 59 females) captive Iberian red deer (Cervus elaphus hispanicus), ranging in age from 21 months to > or =5 years. Skinfold thicknesses were measured immediately before and 72 h following injection.

RESULTS

There was a significant effect of gender on the average increase in skinfold thickness; males had greater increases (8.8 (SEM 0.57) mm) than females (4.23 (SEM 0.39) mm) after correcting for other confounding variables. No age-related differences were evident, but differences between sexes were more marked with increasing age.

CONCLUSIONS AND CLINICAL RELEVANCE

Effects of gender, probably due to differences in energetic and reproductive constraints in red deer, should be taken into account when interpreting skinfold-test data, both in ecology and in the control of tuberculosis (Tb). Males tend to have a thicker skin than females, so skinfold increase relative to the thickness of the skin, rather than skinfold increase per se, should be used as a more appropriate measure of skinfold increase. This may also have clinical relevance in the interpretation of tuberculin skin testing.

In vitro effects of gamma radiation from 60Co and 137Cs on plasmid DNA

The effects of gamma radiation from (60)Co and (137)Cs on DNA in aqueous solution are studied experimentally. Using an improved plasmid purification protocol and improved electrophoretic gel analysis techniques provided results with relatively small uncertainties. The results are compared with both theoretical and experimental results. In particular, the results obtained here are discussed in the light of recent discussion on supposed differences of the effects induced by gamma radiation from (60)Co and (137)Cs. We find that the effects of both types of gamma radiation are similar.

Uranium levels in the diet of São Paulo City residents

Natural levels of uranium in the diet of São Paulo City residents were studied, and radionuclide concentrations were measured by the fission track method on samples of typical adult food items. This information was used to evaluate the daily intake of uranium in individuals living in São Paulo City which is, according to our findings, around 0.97 microg U/day. Using the ICRP Uranium-model, we estimated the uranium accumulation and committed doses in some tissues and organs, as function of time. We compared the output of the ICRP uranium biokinetic model, tailored for the conditions prevailing in São Paulo, with experimental data from other localities. Such comparison was possible by means of a simple method we developed, which allows normalization among experimental results from different regions where distinct values of chronic daily intake are observed.

Long-term accumulation of uranium in bones of Wistar rats as a function of intake dosages

Groups of Wistar rats were fed with ration doped with uranyl nitrate at concentration A ranging from 0.5 to 100 ppm, starting after the weaning period and lasting until the postpuberty period when the animals were sacrificed. Uranium in the ashes of bones was determined by neutron activation analysis. It was found that the uranium concentration in the bones, as a function of A, exhibits a change in its slope at approximately 20 ppm-a probable consequence of the malfunctioning of kidneys. The uranium transfer coefficient was obtained and an analytical expression was fitted into the data, thus allowing extrapolation down to low doses. Internal and localized doses were calculated. Absorbed doses exceeded the critical dose, even for the lowest uranium dosage.

Defective regulation of the protective IgE response against intestinal helminth Ascaris lumbricoides in malnourished children

It is well established that malnutrition affects the immune response and increases the susceptibility to parasitic infection. In the present study we evaluated some aspects of the cellular and cytokine network that regulate the IgE responses, which are important components of host defence mechanisms against helminthic parasites in children infected with the intestinal helminth Ascaris lumbricoides, and with differing degrees of malnutrition. We found a defective T cell response in malnourished children, as indicated by diminished levels of circulating total (CD3+), helper (CD4+), IL-2-receptor-bearing (CD4+CD25+) and memory helper T cell responses (CD4+CD45RO+) in keeping with the decreased specific IgE levels against Ascaris lumbricoides. In contrast, the proportions of total B cells (CD20+), and those bearing the low-affinity IgE receptor (CD23+) were increased in the moderated malnourished children. Moreover, serum IL-4 levels and total IgE were also increased in these children. We suggest that malnutrition can cause an imbalance in T cell subpopulations that may lead to a defective T cell maturation and a decreased specific anti-Ascaris IgE response thus increasing the susceptibility to such infections. The high levels of total IgE observed may be related to a non-specific stimulation of the proliferation of activated B cells, probably caused by helminthic parasites and other infectious agents that are frequent in malnourished children.

Effects of a splitter plate in the near wake of a divergent trailing edge

This paper discusses experimental research aimed at defining a base drag reduction device based on splitter plates. The unsteady three-dimensional nature of the flow is studied by Schlieren photography, particle image velocimetry, and measurement of the total unsteady lift and drag loads.

Safety of ergot stress echocardiography for non-invasive detection of coronary vasospasm

BACKGROUND

The safety of ergonovine/ergometrine stress testing for coronary vasospasm when performed outside the cardiac catheterization laboratory (cath lab) has been questioned vigorously.

AIM

To assess the tolerability and safety of ergonovine/ergometrine stress testing performed in the echocardiographic laboratory (echo lab).

METHODS

We retrospectively reviewed the data prospectively collected in the echo lab of the Institute of Clinical Physiology from 1 January 1985 to 1 June 2000, from 587 tests performed on 573 patients (either ergonovine or ergometrine stress echocardiography testing). By selection, all patients had a history of chest pain, consistent with vasospastic angina, negative exercise stress testing or stress echocardiography (with dipyridamole, dobutamine or exercise), and normal or near normal resting left ventricular function. Ergonovine or ergometrine maleate was injected up to a total cumulative dosage of 0.35 mg, under continuous 12-lead electrocardiographic and two-dimensional echocardiographic monitoring.

RESULTS

There were no deaths, myocardial infarctions, ventricular fibrillations or third degree AV blocks. One patient had non-sustained ventricular tachycardia associated with transient ST segment elevation 30 min after the test. Three patients had second degree AV block associated with a positive echocardiography test that was promptly reversed by nitrates administration. Transient regional myocardial dysfunction occurred in 79 patients (13%). Limiting ischaemia-independent side effects were present in 17 patients (3%): hypotension in one, arterial hypertension in five, non-sustained ventricular tachycardia in two and nausea or vomiting in ten. The test was well tolerated and echocardiograms were interpretable in 97% of the tests performed.

CONCLUSION

Pharmacological stress echocardiography with either ergonovine or ergometrine is well tolerated and can be performed with relatively low risk in the echo lab in properly selected patients in whom coronary vasospasm is suspected.

Detection of epithelial messenger RNA in the plasma of breast cancer patients is associated with poor prognosis tumor characteristics

PURPOSE

Free plasma RNA has been scarcely studied in patients with cancer. Here we examine the presence of RNA from epithelial tumors in plasma from a series of breast cancer patients and its correlation with tumor characteristics and circulating tumor cells.

EXPERIMENTAL DESIGN

beta-actin mRNA was analyzed to check the viability of plasma RNA in samples from 45 patients with breast cancer and 25 controls. Nested primers were used to detect the presence of cytokeratin 19 (CK19) and Mammaglobin in the same samples. Eleven clinicopathological parameters were studied and correlated with molecular parameters. Additionally, we looked for circulating tumor cells in 16 of these patients and in 10 of the controls.

RESULTS

All samples showed detectable quantities of beta-actin RNA. In controls, 3 cases (12%) were positive for Mammaglobin, and 5 (20%) were positive for CK19 RNA; of the 45 patients, 27 cases (60%) were positive for Mammaglobin, and 22 (49%) were positive for CK19. These differences were statistically significant (P = 0.001). Tumor size (P = 0.01) and proliferative index (P = 0.02) were associated with the presence of Mammaglobin, CK19, or both RNAs in plasma. Pathological stage (P = 0.06) was close to significance. Although a statistical relationship was not demonstrated, 9 of the 10 patients with circulating tumor cells showed epithelial mRNAs in plasma.

CONCLUSIONS

We conclude that epithelial tumor RNA is detectable in plasma from breast cancer patients and that this finding is associated with a probable poor prognosis and circulating tumor cells.

Transfer coefficient measurements of uranium to the organs of Wistar rats, as a function of the uranium content in the food

Groups of animals (Wistar rats) were fed with rations doped with uranyl nitrate at concentrations ranging from 0.5 to 100 ppm. The uranium content in the ashes of the organs was measured by the neutron-fission track counting technique. The most striking result is that the transfer coefficients, as a function of the uranium concentration, exhibit a concave shape with a minimum around 20 ppm-U for all organs. Explanations to interpret this finding are tentatively given.

Non-invasive prediction of angiographic progression of coronary artery disease by dipyridamole-stress echocardiography

BACKGROUND

Coronary angiography is the currently accepted standard means for assessing progression of coronary artery disease. A dipyridamole-echocardiography test (DET) might provide an alternative non-invasive functional imaging method for this purpose.

OBJECTIVE

To assess whether variations in results of serial DET match variations in angiographic assessments of coronary artery disease.

METHODS

From the Pisa Institute of Clinical Physiology stress-echocardiography data bank (1983-1998), we selected 60 patients satisfying the inclusion criteria of coronary angiography and DET having each been performed and interpreted twice independently and within 1 week. The second angiographic and stress-echocardiographic assessment was performed 45+/-31 months after the initial one. Angiographic progressors were defined a priori as patients with any progression of stenosis to occlusion and those with any stenosis > 30% with > 20% progression of stenosis measured by visual and quantitative coronary angiography. Stress-echocardiography progressors were defined as those patients who had previously had a negative test of a test having a positive result and those patients who had positive results of tests both in initial testing and in a second session of testing with the latter having a peak wall-motion-score index > 0.12 (on a scale of 1, normal to 4, dyskinetic in a 16-segment model) larger than the former.

RESULTS

Of the 60 patients, 44 were angiographic 'progressors' and 16 were 'non progressors'. Stress-echocardiographic responses were concordant with angiographic identification for 39 of 44 progressors and 15 of 16 non-progressors, with an overall concordance of 90%.

CONCLUSIONS

Measurement of dipyridamole-stress-echocardiographic response allows one to separate angiographic progressors and non-progressors efficiently, simply by taking into account the presence, extent and severity of stress-induced abnormalities of wall motion.

Presence of human T-cell responses to the Mycobacterium leprae 45-kilodalton antigen reflects infection with or exposure to M. leprae

The ability of the 45-kDa serine-rich Mycobacterium leprae antigen to stimulate peripheral blood mononuclear cell (PBMC) proliferation and gamma interferon (IFN-gamma) production was measured in leprosy patients, household contacts, and healthy controls from areas of endemicity in Mexico. Almost all the tuberculoid leprosy patients gave strong PBMC proliferation responses to the M. leprae 45-kDa antigen (92.8%; n = 14). Responses were lower in lepromatous leprosy patients (60.6%; n = 34), but some responses to the 45-kDa antigen were detected in patients unresponsive to M. leprae sonicate. The proportion of positive responses to the M. leprae 45-kDa antigen was much higher in leprosy contacts (88%; n = 17) than in controls from areas of endemicity (10%; n = 20). None of 15 patients with pulmonary tuberculosis gave a positive proliferation response to the 45-kDa antigen. The 45-kDa antigen induced IFN-gamma secretion similar to that induced by the native Mycobacterium tuberculosis 30/31-kDa antigen in tuberculoid leprosy patients and higher responses than those induced by the other recombinant antigens (M. leprae 10- and 65-kDa antigens, thioredoxin, and thioredoxin reductase); in patients with pulmonary tuberculosis it induced lower IFN-gamma secretion than the other recombinant antigens. These results suggest that the M. leprae 45-kDa antigen is a potent T-cell antigen which is M. leprae specific in these Mexican donors. This antigen may therefore have diagnostic potential as a new skin test reagent or as an antigen in a simple whole-blood cytokine test.

Stent thrombosis in the modern era: a pooled analysis of multicenter coronary stent clinical trials

BACKGROUND

There are limited studies of stent thrombosis in the modern era of second-generation stents, high-pressure deployment, and current antithrombotic regimens.

METHODS AND RESULTS

Six recently completed coronary stent trials and associated nonrandomized registries that enrolled 6186 patients (6219 treated vessels) treated with >/=1 coronary stent followed by antiplatelet therapy with aspirin and ticlopidine were pooled for this analysis. Within 30 days, clinical stent thrombosis developed in 53 patients (0.9%). The variables most significantly associated with the probability of stent thrombosis were persistent dissection NHLBI grade B or higher after stenting (OR, 3.7; 95% CI, 1.9 to 7.7), total stent length (OR, 1.3; 95% CI, 1.2 to 1.5 per 10 mm), and final minimal lumen diameter within the stent (OR, 0.4; 95% CI, 0.2 to 0.7 per 1 mm). Stent thrombosis was documented by angiography in 45 patients (0.7%). Clinical consequences of angiographic stent thrombosis included 64.4% incidence of death or myocardial infarction at the time of stent thrombosis and 8.9% 6-month mortality.

CONCLUSIONS

Stent thrombosis occurred in <1.0% of patients undergoing stenting of native coronary artery lesions and receiving routine antiplatelet therapy with aspirin plus ticlopidine. Procedure-related variables of persistent dissection, total stent length, and final lumen diameter were significantly associated with the probability of stent thrombosis. Continued efforts to eliminate this complication are warranted given the serious clinical consequences.

Administration of abciximab to patients receiving tirofiban or eptifibatide: effect on platelet function

OBJECTIVES

The goal of this study was to evaluate platelet function and to preliminarily assess the clinical safety of sequential treatment with tirofiban or eptifibatide followed by abciximab in patients undergoing percutaneous coronary intervention (PCI).

BACKGROUND

An increasing number of acute coronary syndrome (ACS) patients are treated early with tirofiban or eptifibatide. Some later require PCI and may benefit from switching to abciximab, for which long-term benefits have been reported.

METHODS

Fifty ACS patients planned for PCI were enrolled. Twenty-five patients received tirofiban followed by abciximab. Ten patients received eptifibatide followed by abciximab. Fifteen patients received only abciximab. All patients had blood samples drawn six times during the therapeutic course. Platelet function was evaluated by ADP- and TRAP-induced aggregation, flow cytometry analysis of fibrinogen binding and the cone and plate(let) analyzer, which tests shear rate-dependent platelet activation.

RESULTS

Administered after tirofiban, abciximab caused a significant further decline in platelet function, as evidenced by all methods. Administered after eptifibatide, abciximab caused a significant further reduction in platelet function, as assessed by the cone and plate(let) analyzer and fibrinogen binding methods. The platelet inhibition achieved by the combination therapy was always greater than or equal to that achieved by abciximab alone. There were no major bleeding or severe thrombocytopenia episodes. Three of the 35 combination therapy patients and one of the 15 who received abciximab alone had minor bleeding.

CONCLUSIONS

This is the first in vivo study of combination intravenous platelet glycoprotein IIb/IIIa inhibitor therapy. Administration of abciximab immediately after tirofiban or eptifibatide therapy effectively inhibits platelet function and appears to be safe.

Effect of coronary bypass and cardiac valve surgery on systemic endothelial function

Seventeen patients scheduled for a cardiac procedure necessitating cardiopulmonary bypass underwent serial perioperative assessment of brachial artery flow-mediated dilation. Patients who underwent coronary bypass surgery had a sustained systemic endothelial dysfunction in the perioperative period, whereas those undergoing cardiac valve surgery experienced transient postoperative systemic endothelial dysfunction.

Conducting research in culturally diverse inner-city neighborhoods: some lessons learned

Social, behavioral, and health research among disenfranchised groups in inner cities poses problems in collecting data. It is a challenge to achieve data of sufficient quantity and quality necessary to be scientifically usable. This article describes the experiences of a research team during two phases of data collection in a mental health intervention study in New York's South Bronx. Challenges in addressing human subject concerns, the formation of a fieldwork team, enrollment and retention of respondents, and administration of instruments are described and solutions are discussed. Emphasis is placed on researchers' approaches to the selection, orientation, and safety of interviewers, interviewer-respondent race and ethnic matching, contacts and rapport with respondents, and the handling of such interpersonal issues as distrust, poor cooperation, and family dynamics. The procedures developed took into consideration the culture and life conditions of the population to ensure a satisfactory response rate and high-quality data.