Preparedness of the CTSA's structural and scientific assets to support the mission of the National Center for Advancing Translational Sciences (NCATS)

The formation of the National Center for Advancing Translational Sciences (NCATS) brings new promise for moving basic science discoveries to clinical practice, ultimately improving the health of the nation. The Clinical and Translational Science Award (CTSA) sites, now housed with NCATS, are organized and prepared to support in this endeavor. The CTSAs provide a foundation for capitalizing on such promise through provision of a disease-agnostic infrastructure devoted to clinical and translational (C&T) science, maintenance of training programs designed for C&T investigators of the future, by incentivizing institutional reorganization and by cultivating institutional support.

Computer simulating a clinical trial of a load-bearing implant: an example of an intramedullary prosthesis

Computational modelling is becoming ever more important for obtaining regulatory approval for new medical devices. An accepted approach is to infer performance in a population from an analysis conducted for an idealised or 'average' patient; we present here a method for predicting the performance of an orthopaedic implant when released into a population--effectively simulating a clinical trial. Specifically we hypothesise that an analysis based on a method for predicting the performance in a population will lead to different conclusions than an analysis based on an idealised or 'average' patient. To test this hypothesis we use a finite element model of an intramedullary implant in a bone whose size and remodelling activity is different for each individual in the population. We compare the performance of a low Young's modulus implant (E=20 GPa) to one with a higher Young's modulus (200 GPa). Cyclic loading is applied and failure is assumed when the migration of the implant relative to the bone exceeds a threshold magnitude. The analysis for an idealised of 'average' patient predicts that the lower modulus device survives longer whereas the analysis simulating a clinical trial predicts no statistically-significant tendency (p=0.77) for the low modulus device to perform better. It is concluded that population-based simulations of implant performance-simulating a clinical trial-present a very valuable opportunity for more realistic computational pre-clinical testing of medical devices.

Locations and outcomes of premature births in Arkansas

Most (57.6%) of the extremely premature infants were born at a hospital without the availability of neonatal and MFM specialists, and 38.4% of the very premature were born at a hospital without a neonatologist. Increasing evidence indicates that delivery at a Level 3 facility results in better survival for these high risk infants. Health professionals, administrators and policy leaders could fashion new approaches to obstetrical care in Arkansas to improve neonatal outcomes.

Relationship of Anthracycline-Free Interval to Outcomes in a Phase 3 Trial of Pegylated Liposomal Doxorubicin Plus Docetaxel Compared with Docetaxel Monotherapy in Patients with Advanced Breast Cancer Treated with Adjuvant Anthracycline

Background: An earlier report showed that pegylated liposomal doxorubicin (PLD) + docetaxel (D) improved time to progression (TTP) vs D alone in patients (pts) with advanced breast cancer (ABC) who had relapsed at least 1 year after adjuvant or neoadjuvant anthracycline therapy. (Sparano et al., SABC 2008, #80) This analysis evaluated whether the time between completion of adjuvant anthracycline therapy until relapse impacts overall outcome. We retrospectively examined outcomes in pts with an anthracycline-free (A-F) interval of 1 to 2 years and pts with an A-F of >2 years.Methods: 751 pts were randomly assigned to receive either D 75 mg/m2 (N=373) or PLD 30 mg/m2 followed by D 60 mg/m2 (N=378) every 21 days. Treatment was continued until disease progression or the occurrence of unacceptable toxicity. The primary endpoint was TTP and secondary endpoints included overall survival (OS), progression free survival (PFS), objective response rate (ORR), and safety. Pts were categorized into groups by anthracycline-free interval of 1-2 years or >2 years. Relationship between the interval and outcomes was examined by proportional hazards model for TTP, OS (updated as of 1-Dec-2008), and PFS.Results: Approximately 60% of pts in both treatment groups had A-F intervals of >2 years. Median TTP, OS, and PFS (months) by A-F interval groups are listed in the Table. A-F interval 1-2 years  A-F interval >2 years   D, n=151PLD+D, n=155HR (CI)*; P**D, n=221PLD+D, n=221HR (CI)*; P**TTP5.77.80.67 (0.52, 0.87); .0027.710.60.63 (0.50, 0.79); <.001OS15.817.90.90 (0.69, 1.16); .40424.722.91.10 (0.86, 1.40); .448PFS5.57.70.67 (0.52, 0.87); .0027.710.00.65 (0.51, 0.81); <.001ORR25%34%P=.086†27%36%P=.042† A-F interval 1-2 years, N=306  A-F interval >2 years, N=442 HR (CI)***; P**TTP6.6  8.9 0.74 (0.63, 0.88); .001OS17.2  23.4 0.63 (0.52, 0.75); <.001PFS6.5  8.7 0.74 (0.62, 0.87); <.001ORR30%  31% P=.826†*Proportional hazard model for PLD+D vs D; **Log-rank test; ***Proportional hazard model for >2 years vs ≤2 years A-F; †Cochran-Mantel-Haenszel test.Overall, HFS and stomatitis occurred more often in pts treated with PLD+D. The overall incidence of CHF was 1%.Conclusions: An A-F interval of >2 years reduced the risk for TTP, OS, and PFS, regardless of treatment. However, similar to results of the overall study, treatment with the combination PLD+D resulted in statistically significant improvement of TTP and PFS, but not OS, compared with D among pts with ABC, regardless of A-F interval. The addition of PLD to a D-based regimen is an active option for pts with ABC previously treated with adjuvant anthracycline regimens.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2095.

Relationship of rapid M protein reduction to outcomes in a trial of pegylated liposomal doxorubicin (PLD) plus bortezomib (B) versus B alone in previously treated multiple myeloma (MM)

8591

Background: An early response in MM results in rapid improvement in symptoms and may benefit outcomes. To investigate the relationship between rapid response and outcomes, we retrospectively evaluated early reduction in M protein (MProt) in a trial of pegylated liposomal doxorubicin + bortezomib (PLD+B) vs B alone in relapsed/refractory multiple myeloma (MM). (Orlowski, JCO 2007) Methods: Patients (pts) were randomized to bolus IV B 1.3 mg/m2 on days 1, 4, 8, & 11 of each 3-week cycle (N=322) or to the same B regimen + IV PLD 30 mg/m2 on day 4 (N=324) of each cycle. % decrease from baseline of MProt was evaluated using a landmark analysis at the end of cycles 2 and 4. Pts were categorized into 4 groups by reduction in MProt at the landmark timepoints. 199 PLD+B and 205 B pts were included in the analysis at end of cycle 2. Time to progression (TTP) post-landmark was evaluated using a Cox proportional hazard model with treatment and the three ≥25% MProt reduction groups compared to the <25% group as factors. Results: Regardless of treatment, a decrease in risk of TTP was observed for greater reduction in MProt. This was significant for the 50–75% and ≥75% MProt reduction groups. Hazard ratios (95% CI) were: [0.84 (0.55, 1.30), P=.438] for 25-<50% vs 25%; [0.41 (0.26, 0.64), P=.001] for 50-<75% vs <25%; and [0.26 (0.15, 0.45), P=.001] for ≥75% vs <25%. PLD+B had a significant benefit over B alone in extending TTP [1.68 (1.19, 2.37), P=.003]. TTP was longer as MProt decreased and improved for PLD+B vs B. Similar results were observed at the end of cycle 4 landmark. Safety profiles for the 2 regimens were consistent with known toxicities of the agents. Conclusions: PLD+B had significant benefit over B alone in extending TTP in landmark analyses similar to the overall study. A >50% reduction in MProt resulted in a significant risk reduction for progression. These data suggest that early reductions in MProt may provide better outcomes.

[Table: see text]

[Table: see text]

Delayed maturation of auditory-evoked responses in growth-restricted fetuses revealed by magnetoencephalographic recordings

OBJECTIVE

The purpose of this study was to investigate fetal brain development of growth-restricted fetuses with auditory evoked responses (AER) that were recorded by the noninvasive magnetoencephalographic technique.

STUDY DESIGN

Serial fetal recordings that started at 27 weeks of gestation were conducted on a fetal magnetoencephalographic device that was especially designed for obstetric assessment. Fifteen normotrophic fetuses were compared with 14 hypotrophic fetuses. After birth, 10 of the hypotrophic fetuses were diagnosed with asymmetric growth restriction; 4 fetuses were classified as symmetrically small for gestational age.

RESULTS

Fetal AER latencies in both groups showed an average developmental decrease of 12.74 msec/wk (P = .0035). Hypotrophic fetuses had longer age-adjusted latencies compared with normotrophic fetuses, with a difference of 73.5 msec (P = .034). The subgroup of symmetrically growth-restricted fetuses showed the longest latencies for age, with a difference from the normotrophic fetuses of 120.0 msec (P = .045).

CONCLUSION

The results indicate that biomagnetically recorded AER can be used to monitor functional brain development in growth-restricted fetuses.

Acoustic backscatter and effective scatterer size estimates using a 2D CMUT transducer

Compared to conventional piezoelectric transducers, new capacitive microfabricated ultrasonic transducer (CMUT) technology is expected to offer a broader bandwidth, higher resolution and advanced 3D/4D imaging inherent in a 2D array. For ultrasound scatterer size imaging, a broader frequency range provides more information on frequency-dependent backscatter, and therefore, generally more accurate size estimates. Elevational compounding, which can significantly reduce the large statistical fluctuations associated with parametric imaging, becomes readily available with a 2D array. In this work, we show phantom and in vivo breast tumor scatterer size image results using a prototype 2D CMUT transducer (9 MHz center frequency) attached to a clinical scanner. A uniform phantom with two 1 cm diameter spherical inclusions of slightly smaller scatterer size was submerged in oil and scanned by both the 2D CMUT and a conventional piezoelectric linear array transducer. The attenuation and scatterer sizes of the sample were estimated using a reference phantom method. RF correlation analysis was performed using the data acquired by both transducers. The 2D CMUT results indicate that at a 2 cm depth (near the transmit focus for both transducers) the correlation coefficient reduced to less than 1/e for 0.2 mm lateral or 0.25 mm elevational separation between acoustic scanlines. For the conventional array this level of decorrelation requires a 0.3 mm lateral or 0.75 mm elevational translation. Angular and/or elevational compounding is used to reduce the variance of scatterer size estimates. The 2D array transducer acquired RF signals from 140 planes over a 2.8 cm elevational direction. If no elevational compounding is used, the fractional standard deviation of the size estimates is about 12% of the mean size estimate for both the spherical inclusion and the background. Elevational compounding of 11 adjacent planes reduces it to 7% for both media. Using an experimentally estimated attenuation of 0.6 dB cm(-1) MHz(-1), scatterer size estimates for an in vivo breast tumor also demonstrate improvements using elevational compounding with data from the 2D CMUT transducer.

ANGELS and University of Arkansas for Medical Sciences paradigm for distant obstetrical care delivery

OBJECTIVE

This article describes the process by which the Arkansas Medicaid Program, the University of Arkansas for Medical Sciences (the state's only academic health center), and Arkansas' practicing physicians are collaborating to improve the process of perinatal regionalization by providing access to expertise, education, and support of maternal-fetal medicine specialists. The described ANGELS model encourages replication among other programs that wish to improve perinatal regionalization attempts in their service areas.

STUDY DESIGN

Through this unique collaboration, ANGELS is composed of 5 distinctive elements: a statewide telemedicine and clinic network, an education and support program for obstetric providers, case management services, a 24-hour Call Center, and an evidence-based guidelines development and distribution network.

RESULTS

Since Arkansas has undertaken perinatal regionalization, technology has allowed the state's only group of board-certified maternal-fetal medicine specialists, located centrally in Little Rock, to provide real-time clinical support to physicians, as well as consultation or direct care to patients statewide.

CONCLUSION

ANGELS' continued efforts have the potential to significantly improve perinatal care in rural areas throughout the state, while the cost of maternal and fetal health care could decline. The program's design, although unique, can be replicated elsewhere to encourage perinatal regionalization.

Serial magnetoencephalographic study of fetal and newborn auditory discriminative evoked responses

The mismatch negativity (MMN) response elicited to auditory stimuli is an indicator for cognitive function of sound discrimination in humans. MMN was successfully recorded in previous studies in newborns and fetuses (33-40 weeks of gestation) with magnetoencephalography (MEG). The aim of our study was to perform systematic serial MMN recordings on fetuses starting at 28 weeks of gestation with a follow up recording within 2 weeks after birth. The recording of weak magnetic fields from the fetal brain were performed with the 151 channel MEG system called SARA (SQUID Array for Reproductive Assessment). Two tone bursts were presented in a sequence of a standard complex tone of 500 Hz intermixed with a deviant complex tone of 750 Hz in 12% of the stimuli, inter-stimulus interval 800+/-100 ms. Eighteen pregnant women between 28th and 39th gestational weeks participated in the study. Measurements were performed every two weeks and once after delivery. The averaged evoked responses to standard and deviant tones were obtained and subtraction between them was calculated. A successful detection of response to the frequency change was found in 66% of the fetal data and 89% of the neonatal data. Responses to the standard tone were detected in 56% of all records. In the 28-39 week gestational age group, the discriminative brain responses to tone frequency change could be detected as early as 28 weeks. Although not statistically significant, a decrease in latency was observed with increase in gestational age. The ability of the fetus to detect changes in sounds is a prerequisite to normal development for cognitive function; related to language learning and clinical aspects of auditory disorders.

Sound frequency change detection in fetuses and newborns, a magnetoencephalographic study

The mismatch negativity (MMN) response to auditory stimuli has been successfully recorded in newborns thus demonstrating the discriminative cognitive ability. The aim of our study was to determine whether and when such an MMN response could be detected in the human fetus. The recordings of weak magnetic fields from the fetal brain were performed with the 151 channel MEG system called SARA (SQUID Array for Reproductive Assessment). Two tone bursts were presented in a sequence of a standard complex tone of 500 Hz intermixed with a deviant complex tone of 750 Hz in 12% of the stimuli. Sound intensity delivered over the maternal abdomen was 110 dB. The interstimulus interval (ISI) varied between 500 ms and 1100 ms. Fetal response, corresponding to sound frequency change detection, was calculated from the records where responses to standard and deviant tones were observed. A successful response was found in 60% of 25 fetal recordings. The MMN response with an average latency of 321 ms was observed in 48% of the fetal data. In 12% of the fetal data, a late component, referred to as the late discriminative negativity (LDN) response, was detected with an average latency of 458 ms. The same paradigm was applied in 5 newborns after birth. The capability for sound discrimination is a prerequisite for normal speech development. The investigation of sound discrimination and related cortical activity of the fetus can help to identify and determine the nature of deficits caused by central processes in the auditory system at very early stages.

Synchronization analysis of the uterine magnetic activity during contractions

Background

Our objective was to quantify and compare the extent of synchronization of the spatial-temporal myometrial activity over the human uterus before and during a contraction using transabdominal magnetomyographic (MMG) recordings. Synchronization can be an important indicator for the quantification of uterine contractions.

Methods

The spatialtermporal myometrial activity recordings were performed using a 151-channel noninvasive magnetic sensor system called SARA. This device covers the entire pregnant abdomen and records the magnetic field corresponding to the electrical activity generated in the uterine myometrium. The data was collected at 250 samples/sec and was resampled with 25 samples/sec and then filtered in the band of 0.1–0.2 Hz to study the primary magnetic activity of the uterus related to contractions. The synchronization between a channel pair was computed. It was inferred from a statistical tendency to maintain a nearly constant phase difference over a given period of time even though the analytic phase of each channel may change markedly during that time frame. The analytic phase was computed after taking Hilbert transform of the magnetic field data. The process was applied on the pairs of magnetic field traces (240 sec length) with a stepping window of 20 sec duration which is long enough to cover two cycle of the lowest frequency of interest (0.1 Hz). The analysis was repeated by stepping the window at 10 sec intervals. The spatial patterns of the synchronization indices covering the anterior transabdominal area were computed. For this, regional coil-pairs were used. For a given coil, the coil pairs were constructed with the surrounding six coils. The synchronization indices were computed for each coil pair, averaged over the 21 coil-pairs and then assigned as the synchronization index to that particular coil. This procedure was tested on six pregnant subjects at the gestational age between 29 and 40 weeks admitted to the hospital for contractions. The RMS magnetic field for each coil was also computed.

Results

The results show that the spatial patterns of the synchronization indices change and follow the periodic pattern of the uterine contraction cycle. Spatial patterns of synchronization indices and the RMS magnetic fields show similarities in few window frames and also show large differences in few other windows. For six subjects, the average synchronization indices were: 0.346 ± 0.068 for the quiescent baseline period and 0.545 ± 0.022 at the peak of the contraction.

Discussion

These results show that synchronization indices and their spatial distributions depict uterine contractions and relaxations.

Development of auditory evoked fields in human fetuses and newborns: A longitudinal MEG study

OBJECTIVE

To investigate the maturation of the auditory cortex by non-invasive recording of auditory evoked magnetic fields in human fetuses and newborns with the relatively novel and completely non-invasive technology of MEG.

METHODS

Serial recordings were performed every 2 weeks on 18 fetuses beginning from week 27 of gestational age until term with a follow-up recording on the newborn. Auditory stimulation consisted of tone bursts in an oddball design with standard tones and deviant tones.

RESULTS

In 52 of 63 fetal and in all of the neonatal recordings an auditory evoked magnetic field was obtained. A decrease in latency with increasing age of the subjects was observed in the combined analysis of fetuses and neonates.

CONCLUSIONS

With advanced study using MEG, 83% of the measurements showed auditory evoked fields in fetuses that correspond with existing literature in electrophysiology in the past. These findings indicate that MEG is a technique that can be used to investigate maturation of the auditory cortex based on auditory evoked fields in fetuses and neonates.

SIGNIFICANCE

Maturational changes have been examined in the past. With the use of this novel technique, applied to a serial study, it is possible to trace the development of auditory responses in utero and newborns.

Analysis of uterine contractions: a dynamical approach

The development of suitable techniques for quantifying mechanical and electrophysiological aspects of uterine contractions has been an active area of research. The uterus is a physiological system consisting of a large number of interacting muscle cells. The activity of these cells evolves with time, a trait characteristic of a dynamical system. While such complex physiological systems are non-linear by their very nature, whether this non-linearity is exhibited in the external recording is far from trivial. Traditional techniques such as spectral analysis have been used in the past, but these techniques implicitly assume that the process generating the contractions is linear and hence may be biased. In this tutorial review, a systematic approach using a hierarchy of surrogate algorithms is used to determine the nature of the process generating the contractions produced during labor. The results reveal that uterine contractions are probably generated by non-linear processes. The contraction segments were obtained through simultaneous recordings of the electrical and magnetic signals corresponding to the electrophysiological activity of the uterus and then analyzed. The electrical activity was recorded by placement of non-invasive electrodes onto the maternal abdomen and magnetic activity was recorded non-invasively using a superconducting quantum interference device (SQUID).

[New perspectives in intrauterine surveillance with the fetal magnetoencephalogram]

PURPOSE

Despite intensive research and surveillance up to now one has failed to reduce cerebral handicaps in newborn. Fetal heart rate tracing (CTG) and Doppler have reduced the number of subpartal severe asphyxia and fetal death. But, 90% of cerebral damage is a result of antepartal problems. Thus only 10% can be avoided by intensive surveillance during labor. Detection of antenatal cerebral injury is a rare case and its impact on later fetal life can only be estimated. Insight in fetal neuronal function is not possible. Factors and time pattern determining fetal cerebral injury are thus not known. This publication explains a new system with whom one might be able to get more insight in cerebral wellbeing during the fetal intrauterine life.

METHODS AND RESULTS

A new diagnostic approach is set up by recording fetal magnet encephalographic signals (fMEG) thus offering the opportunity to detect fetal brain function. An array which was especially designed to fit to the pregnant body consists of 151 sensors which are able to record the fMEG. Clinical testing is performed in the moment at the UAMS in Little Rock, Arkansas in Cooperation with the Institutes for Medical Psychology and the Frauenklinik in Tiibingen. First results and arising questions are published.

CONCLUSION

With this new system a deeper insight into the fetal neuronal development and fetal wellbeing during pregnancy might be achieved thus reforming the fetal surveillance in the 21st century.