Electron Temperature Measurements Using a Two-Filter Soft X-ray Array in VEST

A multichannel soft X-ray (SXR) array has been developed to measure the electron temperature in the Versatile Experiment Spherical Torus (VEST). To estimate electron temperature using the two-filter method applied to SXR intensity, we designed a pinhole camera that has two photodiode arrays with different metallic filters. We also adopted a filter wheel and tested various filter parameters to find the optimal filter set. Through tests, the combination of aluminum and beryllium was found to be the most suitable for the current experimental conditions in VEST. The filtered SXR signals were acquired with a low-noise preamplifier, exhibiting sufficient signal-to-noise ratios for electron temperature estimation based on the intensity ratio of two signals obtained with different filters. The estimated electron temperature from the developed two-filter SXR array showed reasonably matched levels and consistent trends with Thomson scattering measurements. Error contribution from impurity line emission is also discussed.

GS-DeepNet: mastering tokamak plasma equilibria with deep neural networks and the Grad-Shafranov equation

The force-balanced state of magnetically confined plasmas heated up to 100 million degrees Celsius must be sustained long enough to achieve a burning-plasma state, such as in the case of ITER, a fusion reactor that promises a net energy gain. This force balance between the Lorentz force and the pressure gradient force, known as a plasma equilibrium, can be theoretically portrayed together with Maxwell's equations as plasmas are collections of charged particles. Nevertheless, identifying the plasma equilibrium in real time is challenging owing to its free-boundary and ill-posed conditions, which conventionally involves iterative numerical approach with a certain degree of subjective human decisions such as including or excluding certain magnetic measurements to achieve numerical convergence on the solution as well as to avoid unphysical solutions. Here, we introduce GS-DeepNet, which learns plasma equilibria through solely unsupervised learning, without using traditional numerical algorithms. GS-DeepNet includes two neural networks and teaches itself. One neural network generates a possible candidate of an equilibrium following Maxwell's equations and is taught by the other network satisfying the force balance under the equilibrium. Measurements constrain both networks. Our GS-DeepNet achieves reliable equilibria with uncertainties in contrast with existing methods, leading to possible better control of fusion-grade plasmas.

Development of a scintillator-based optical soft x-ray (OSXR) diagnostic system for KSTAR tokamak

We have developed a new scintillator-based optical soft x-ray (OSXR) diagnostic system for KSTAR. By utilizing fiber optic faceplates, mm-size lens arrays, and fiber bundles, we have successfully constructed a novel optical system for scintillator-based soft x-ray detection to overcome the limited vacuum-port conditions in KSTAR. P47 (Y2SiO5), which has a fast rise (∼7 ns) and decay (∼100 ns) time sufficient for detecting plasma instabilities observed in the kHz-MHz spectral range, was selected as the scintillator material for the KSTAR OSXR system. Scintillation toward each detection channel is collected by the lens arrays coupled to optical fiber cores, which are connected to the photodetector system. Initial results obtained during the 2022 KSTAR experimental campaign support the validity of the OSXR data through the consistency of OSXR measurement results with other diagnostics. We also observe that the OSXR system can capture magnetohydrodynamic activities, such as sawtooth oscillations, and provide valuable information for disruption mitigation studies using shattered pellet injection.

Development of a soft x-ray (SXR) array diagnostic system on versatile experiment spherical torus (VEST)

A new soft x-ray (SXR) array diagnostic system has been developed on versatile experiment spherical torus (VEST) for measurements of 2D SXR emissivity profile and identification of poloidal mode structure. Through tomographic inversion techniques, 2D SXR emissivity profile can be acquired from the line-integrated SXR data, which enables the visualization of mode structure of plasma instability, such as the magnetohydrodynamics mode. The SXR array diagnostic system consists of two 20-channel arrays positioned at the middle and the top on the same poloidal plane for horizontal and vertical lines of sight, respectively. Each array of the diagnostic system uses absolute extreme ultraviolet photodiode array as the detector. To apply appropriate filters (up to four) for different energy regimes without breaking the vacuum, a filter wheel and its rotatable vacuum feed-through are installed behind the pinhole. SXR data are acquired with a digitizer at the sampling rate of up to 125 MHz. Finally, we discuss initial measurement data obtained from Ohmic plasma in VEST.

P-117 A novel method to select spermatozoa with the best morphokinetic characteristics and superior genomic integrity

Study question

Can an automated device based on membrane electrophoresis be used to select spermatozoa with superior morphokinetic characteristics and lower sperm chromatin fragmentation (SCF)?

Summary answer

Albeit at an expense of concentration, a membrane-electrophoretic device was able to isolate a proportion of spermatozoa with the highest motility, morphology, and genomic integrity.

What is known already

Conventional sperm selection based on density gradient centrifugation (DGC) can enhance the proportion of progressively motile spermatozoa; however, DGC methods are limited in their ability to select spermatozoa with higher genomic integrity. Membrane-based microfluidic technologies (MFSS) have already been used clinically to select for spermatozoa with a superior chromatin status; however, these methods are based on the intrinsic characteristics of motile spermatozoa capable of selecting themselves. By incorporating an extrinsic electrophoretic drive, membrane electrophoresis would overcome a limitation of progressive motility in the semen sample and be able to isolate viable gametes with better morphology and reduced SCF.

Study design, size, duration

From August 2020 to December 2021, semen samples from 68 men were evaluated by standard semen analysis and simultaneously processed by DGC or a novel membrane-electrophoretic sperm sorter (EPSS) to select for progressively motile spermatozoa. Concentration, motility, progressive motility, morphology, and SCF were measured and compared between raw, DGC-, and EPSS-processed specimens.

Participants/materials, setting, methods

Fresh ejaculates were evaluated by standard semen analysis according to WHO 2021 criteria. Following complete liquefaction, specimens were divided into two equal aliquots for DGC and EPSS sorting. SCF was assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay under fluorescent microscopy; at least 500 spermatozoa were evaluated for each specimen with a normal threshold of ≤ 15%.

Main results and the role of chance

A total of 68 men with an average age of 38.1±6 years had the following average semen parameters: volume of 3.1±1 mL, concentration of 58.2±33 x106/mL, 43.3±9% motility, 40.5±9% forward progression motility, and a normal morphology of 2.9±0.8%. When comparing the final parameters between the EPSS and DGC methods, despite a reduced sperm concentration (7.3±9 x106/mL vs 45.0±36 x106/mL, P<0.0001, respectively), EPSS was highly selective for motile spermatozoa, yielding significantly higher motility (93.1±16% vs. 86.8±15% P<0.0001) and forward progressive motility (92.3±17% vs 85.2±15%, P<0.0001). Despite an overall lower sperm recovery rate (21.4±25% vs 75.4±17%, P<0.0001), normal morphology improved to 3.4±0.8% (P<0.0001) after EPSS but remained unchanged in the DGC-processed sample. Although both EPSS and DGC improved SCF from 12.2±9% in the raw specimen to 4.8±6% and 6.6±7% (P < 0.0001), respectively, EPSS outperformed DGC (P < 0.05). Moreover, the DGC method took up to 60 min to process, whereas the EPSS technique took a total of 6 min.

Limitations, reasons for caution

The selection of spermatozoa by EPSS is a promising technique to isolate progressively motile spermatozoa with enhanced morphology and superior chromatin integrity, albeit at a lower concentration. This is a preliminary study; the benefit and safety of this method must be further demonstrated by insemination or IVF treatment.

Wider implications of the findings

A membrane electrophoresis device may be a viable alternative method to MFSS to identify spermatozoa with superior morphokinetic characteristics and intact chromatin. Moreover, incorporating an automated device can reduce gamete processing time while minimizing labor costs and inter-operator errors.

Trial registration number

N/A

P-111 Spermiogenic maturation in relation to sperm genomic integrity throughout the epididymis

Study question

Which portion of the epididymis yields spermatozoa with the highest chromatin integrity and embryo developmental competence?

Summary answer

Spermatozoa retrieved from the distal portion of the epididymis retains the highest chromatin integrity, characterized by higher fertilization, implantation, and clinical pregnancy rates.

What is known already

Surgical sperm retrieval from the proximal male reproductive tract has proven to be an effective treatment for couples with recurrent pregnancy loss due to high DNA fragmentation in the ejaculate. Although spermatozoa retrieved directly from the germinal epithelium displays the highest genomic integrity, epididymal spermatozoa maintain a similar DNA integrity profile but yield higher fertilization and pregnancy rates. Although the caput is the preferred site for sperm aspiration procedures in the epididymis, it is unclear which epididymal region yields the best-quality gametes.

Study design, size, duration

Over a 10-year period, we identified 51 obstructive azoospermic (OA) men who underwent surgical sperm retrieval. These men were grouped according to the different epididymal regions from which their spermatozoa were obtained. Sperm chromatin fragmentation (SCF) was assessed and compared among these groups. The epididymal spermatozoa were then used for ICSI cycles. Fertilization and clinical outcomes were compared among the epididymal regions. All female partners (≤37 years old) had negative infertility workups.

Participants/materials, setting, methods

Epididymal spermatozoa were retrieved from the caput (n = 39), corpus (n = 8), and cauda (n = 4) regions. SCF was assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, with a normal threshold of ≤ 15%. Unpaired t and Fisher’s exact tests were used to compare the SCF as well as ICSI and pregnancy outcomes according to the epididymal sperm source. P < 0.05 was considered statistically significant.

Main results and the role of chance

A total of 51 men were categorized based on the site of spermatozoa retrieval: caput, corpus, and cauda. Maternal age was comparable among all three groups (37.9±5, 37.3±4, and 38±3, respectively). Sperm concentration was 23.9±30x106/ml (caput), 24.3±30x106/ml (corpus), and 29.3±36x106/ml (cauda), with 10.8±15% (caput), 14.3±20%(corpus), and 15.2±13% motility (cauda). Average oocytes injected per group was 13.3, 12.3, and 13.2, respectively. Average SCF scores were 19.8%, 9.2% (P < 0.05), and 8.4% (P < 0.05), respectively. The fertilization rates rose from 69.0% in the caput to 78.6% in the corpus and 86.2% (P < 0.05) in the cauda. Implantation rates followed a similar trend: 35.3% in the caput and 44.4% and 50.1% in the corpus and cauda, respectively. In cycles using caput epididymal spermatozoa, there was a 52.9% delivery rate with a 5.5% pregnancy loss rate. Cycles using corpus epididymal sperm showed a 75.0% delivery rate with no pregnancy loss. Finally, cycles using spermatozoa from the cauda resulted in a 100% delivery rate.

Limitations, reasons for caution

Although spermatozoa retrieved from the cauda epididymis has superior genomic integrity and yielded satisfactory clinical outcomes, this approach may be restricted to patients with obstructive azoospermia. While we attempted to control for an eventual confounding female factor, it cannot be entirely ruled out.

Wider implications of the findings

The epididymis plays an important role in sperm maturation; epididymal spermatozoa retain adequate chromatin integrity as demonstrated by the fertilization and pregnancy rates achieved with sperm retrieved from the cauda region. Confirmation of these findings in larger studies may help determine the most favorable site for epididymal sperm retrieval.

Trial registration number

Not applicable

O-251 Defining the exclusive role of male genome integrity on conceptus development

Study question

To determine the effect of sperm DNA fragmentation on embryo development by ruling out a female factor component.

Summary answer

By utilizing healthy donor oocytes, it is possible to quantify the sole deleterious effect of sperm DNA fragmentation and explore the ooplasmic repair mechanism.

What is known already

In approximately 50% of couples with unexplained ART failure, a subtle male factor is present that is missed in a conventional semen analysis assessing concentration, motility, and morphology. Additional information on male gamete competence can be acquired by assessing Sperm Chromatin Fragmentation (SCF). Indeed, a fragmented male genome can give rise to poorly developing embryos, leading to impaired implantation, lower pregnancy, and higher miscarriage rates. It has been previously seen that an oocyte, according to its age, can repair the damaged DNA contributed by the male gamete.

Study design, size, duration

In last decade, 316 couples, who have an elevated SCF, underwent ICSI cycles and resulted in disappointing clinical outcomes. To exclude an eventual confounding female factor, couples who utilized donor oocytes were identified and clinical outcome was compared to a control. To measure the role of an impaired sperm genome and a concurrent oocyte repair mechanism, we compared clinical outcomes between cycles in the same couples who used their own and subsequently donor oocytes.

Participants/materials, setting, methods

We included 381 couples screened for SCF; 65 underwent ICSI cycles with donor oocytes; of these, 46 underwent a previous ICSI cycle with their own oocytes. Fertilization, implantation, clinical pregnancy, and delivery rates were compared between above-mentioned groups. A TUNEL assay was used to measure SCF (≥500 spermatozoa were assessed/sample at a 15% threshold). Paired t and Chi-square tests were used to compare ages and clinical outcomes, respectively.

Main results and the role of chance

We included 381 couples (maternal age, 37.8 ± 4.2; paternal age, 41.8 ± 8.2), whose male partners had the following semen parameters: average volume of 2.5 mL, concentration of 25.4x106/mL, 33% motility, and normal morphology of 1.7. Of these, 316 had elevated average DNA fragmentation of 25.5% and utilized their own oocytes in 683 ICSI cycles, resulting in a 67.5% fertilization, 12.2% implantation, 27.9% clinical pregnancy, and a 22.5% ongoing/delivery. Of the 381 couples, 65 underwent ICSI utilizing donor oocytes (SCF of 24.3%) resulting in a significantly higher fertilization (78.4%) (P < 0.00001) and embryo implantation rates (34.2%) (P < 0.0001). Similarly, albeit not statistically significant, the clinical pregnancy and ongoing/delivery rates increased from 27.9% to 37.1% and from 22.5% to 30.0%, respectively.

To further explore the exclusive role of the male gamete in embryo development, we identified a cohort of patients (n = 46), with an elevated average DNA fragmentation of 23.6%, who underwent an ICSI cycle using their own oocytes and a subsequent cycle using donor oocytes. Compared to cycles where couples used their own oocytes, fertilization, embryo implantation, clinical pregnancy, and ongoing/delivery rates rose from 67.5% to 76.6% (P < 0.0001), 2.8% to 24.7% (P < 0.00001), 8.4% to 38.8% (P < 0.0001), and 1.2% to 28.6% (P < 0.00001), respectively.

Limitations, reasons for caution

Although this study attempts to control for a concurrent confounding female factor, it cannot be completely excluded. It is difficult to assess the extent and contribution of the ooplasmic repair mechanisms on the male genome.

Wider implications of the findings

Ooplasmic repair mechanisms of healthy female gametes appear to repair or improve the deleterious impact of sperm DNA fragmentation on ART outcomes.

Trial registration number

not applicable

O-314 Epigenetic Profiling of Seminal Plasma in NOA Men to Predict Successful Testicular Sperm Retrieval

Study question

Can epigenetic profiling of seminal plasma be used to predict successful testicular sperm retrieval for men with non-obstructive azoospermia (NOA)?

Summary answer

Epigenetic screening of cell-free seminal RNA identified gene imbalances in NOA men, with specific correlation to those who failed to yield spermatozoa at testicular biopsy.

What is known already

Although the chance of a successful microdissection testicular sperm extraction (micro-TESE) in men with NOA can be up to 60%, the procedure may still fail to yield spermatozoa. Several factors have been proposed to predict a successful retrieval, including FSH, inhibin B, genetics, and histopathology. Although histopathology would be the most reliable of these to predict successful micro-TESE, it is equally invasive to perform. Indeed, cell-free RNA extracted from testicular biopsy specimens has been shown to be differentially expressed in infertile men according to the origin of their azoospermia, whether obstructive or nonobstructive, and in relation to a normozoospermic control.

Study design, size, duration

Over a 2-year period, we identified men in whom no spermatozoa were identified despite extensive semen analyses conducted by multiple embryologists. These patients, who were negative for Y microdeletion, subsequently underwent micro-TESE. For consenting men, we performed epigenetic analyses on their seminal plasma by RNAseq. Significant differentially expressed gene (DEG) profiles were then assessed and compared according to whether surgical sperm retrieval successfully yielded spermatozoa (+TESE) or not (-TESE).

Participants/materials, setting, methods

RNA was isolated from the ejaculates for RNAseq using a commercially available spin column kit. RNA isolates were sequenced by Illumina HiSeq at 2x150bp. An absolute log2fold change of > 1 and a P-value of < 0.05 was considered significant. DEG profiles were compared within, as well as between, the +TESE and -TESE cohorts in comparison to a donor control.

Main results and the role of chance

All 12 men (37.3±6yrs) had normal peripheral karyotypes. Six (38.0±7yrs) underwent successful testicular sperm retrievals, defining the +TESE cohort. These men exclusively shared 10 significantly imbalanced genes involved in processes such as spermatogenesis (n = 4), sperm function (n = 2), and testis development (n = 1).

For the 6 men (36.6±5 yrs) who underwent testicular sperm retrievals that failed to yield spermatozoa (-TESE), we identified 16 significantly imbalanced genes, exclusively shared by these patients. These genes are mainly involved in spermatogenesis (n = 9), sperm maturation (n = 1), and cell cycle regulation (n = 4).

We then compared the DEG profiles between the +TESE and -TESE cohorts and identified 8 imbalanced genes that were shared among all 12 NOA men.

Of interest, TPTE2 was partially (67%) expressed in patients from the +TESE group, while IGSF11-AS1 was underexpressed in all men from the -TESE group. Both of these genes are implicated in spermatogenic defects and are normally highly expressed in the testis.

Interestingly, we identified a gene (NA) that was solely and specifically underexpressed in all men from the -TESE group, yet simultaneously overexpressed in all men from the +TESE group. NA, which is well known for its role in sialic acid metabolism, is also present on the sperm acrosome.

Limitations, reasons for caution

Using non-invasive RNAseq on the seminal plasma of NOA men, we were able to identify DEGs according to whether spermatozoa were successfully retrieved or had failed retrieval with micro-TESE. Although intriguing, these are preliminary results that should be further validated in a larger study cohort.

Wider implications of the findings

RNAseq identified genes shared within the same prognostic cohort. Moreover, differential expression of some specific genes predicted micro-TESE outcome. This epigenetic assessment, carried out on the ejaculate, can therefore be used as a non-invasive biomarker tool to predict loss of spermatogenesis in NOA men, sparing them from unnecessary surgery.

Trial registration number

N/A

P-112 Utilizing surgical sperm retrieval to improve clinical outcomes for men with high sperm chromatin fragmentation in their ejaculates

Study question

In men with elevated sperm chromatin fragmentation (SCF), can surgical sperm retrieval from the proximal area of the male genital tract improve clinical outcomes?

Summary answer

Spermatozoa retrieved from the epididymis or testes demonstrate higher genomic integrity and are associated with enhanced embryo implantation, clinical pregnancy, and delivery rates.

What is known already

Sperm genomic integrity is a key factor in achieving a successful pregnancy. During spermiogenesis, alteration of DNA topology involving nuclease and ligase mechanisms is required for supercoiling and DNA compaction. If a proper DNA repair mechanism fails during this intricate process, spermatozoa with DNA fragmentation should be picked up by the epididymis and phagocytized. When this mechanism fails, along with the presence of superimposed reactive oxygen species in the male genital tract, spermatozoa with DNA fragmentation may reach the ejaculates. We have previously demonstrated that retrieving spermatozoa directly from the epididymis and testes yields gametes with higher conserved genomic integrity.

Study design, size, duration

In a nine-year timespan, we identified over 1,000 men with high SCF in their ejaculates; 144 patients consented to undergo surgical retrieval of spermatozoa. In a preliminary assessment, their clinical outcomes were compared to those from men with normal SCF (n = 539). Of these men, 53 consented to undergo subsequent ICSI cycles with their female partners using surgically retrieved spermatozoa from the epididymis (n = 15) or testes (n = 38). Fertilization and clinical outcomes were compared.

Participants/materials, setting, methods

Ejaculated, epididymal, and testicular specimens were screened by terminal deoxynucleotidyl dUTP nick-end labeling (TUNEL) to assess SCF using a commercially available kit. A total of 500 spermatozoa/sample were screened with a normal threshold of 15%. Surgical samples from the epididymis and testes were cryopreserved in multiple vials for subsequent ICSI cycles.

Main results and the role of chance

In the preliminary assessment, ICSI outcomes utilizing ejaculated spermatozoa were compared between men with normal (n = 539, 9.3±3%) and abnormal (n = 144, 28.2±13%) SCF. Although fertilization did not differ, implantation (24.1% vs. 7.8%) and clinical pregnancy rates (CPR, 35.8% vs. 14.6%) were significantly impaired (P < 0.001) in men with elevated SCF.

SCF assessment on surgically retrieved spermatozoa revealed a decreasing trend from 28.2±13% in the ejaculate to 16.6±9.2% in the epididymis and 10.1±5.7% in the testes.

A total of 53 men underwent 79 subsequent ICSI cycles using surgically retrieved spermatozoa. Compared to their historical cycles using ejaculates (n = 65), ICSI with surgically retrieved sperm substantially improved implantation (18.8% vs. 2.1%; P < 0.001), CPR (36.5% vs. 5.3%; P < 0.0001), and ongoing/delivery rates (33.8% vs. 4.1%; P < 0.0001).

Among these couples, 15 underwent 21 ICSI cycles utilizing epididymal spermatozoa with a mean SCF of 16.6±9%. Implantation (26.5% vs. 3.7%; P < 0.05), CPR (68.4% vs. 4.2%; P < 0.0001), and ongoing/delivery rates (57.1% vs. 4.2%; P < 0.0001) were significantly improved compared to the historical cycles.

The remaining 38 patients underwent ICSI with testicular spermatozoa with an average SCF of 10.1±6%. Implantation (15.0% vs. 2.6%; P < 0.01), CPR (25.5% vs. 6.1%; P < 0.01), and ongoing/delivery rates (23.6% vs. 3.0%; P < 0.05) were higher when compared to historical cycles.

Limitations, reasons for caution

Although surgically retrieved spermatozoa can be used to enhance clinical outcomes in couples with high SCF, epididymal spermatozoa yielded higher pregnancy rates despite the higher level of SCF in these specimens compared to testicular spermatozoa. This can be explained by the corrective action of the ICSI procedure itself.

Wider implications of the findings

Our study demonstrated that sperm DNA integrity progressively increases through the journey of the male genital tract. In couples with a compromised sperm genome, surgically retrieved spermatozoa can be beneficial. Therefore, assessing SCF might be used a routine tool to evaluate the male gamete.

Trial registration number

N/A

RRAM-based synapse devices for neuromorphic systems

Hardware artificial neural network (ANN) systems with high density synapse array devices can perform massive parallel computing for pattern recognition with low power consumption. To implement a neuromorphic system with on-chip training capability, we need to develop an ideal synapse device with various device requirements, such as scalability, MLC characteristics, low power operation, data retention, and symmetric/linear conductance changes under potentiation/depression modes. Although various devices have been proposed for synapse applications, they have limitations for application in neuromorphic systems. In this paper, we will cover various RRAM synapse devices, such as filamentary switching RRAM (HfOx, TaOx, Cu-CBRAM) and analog RRAM devices, based on interface resistive switching (Pr0.7Ca0.3MnOx and TiOx) and ferroelectric polarization (HfZrOx). By optimizing potentiation/depression conditions, we could improve the conductance linearity and MLC characteristics of filamentary synapse devices. Interface RRAM has better MLC characteristics with limited retention and conductance linearity. By controlling the reactivity of metal electrodes and the oxygen concentration in oxides, we can modulate the synapse characteristics. Metal-Ferroelectric-Insulator-Semiconductor (MFIS) FET devices exhibit good retention characteristics and analog memory characteristics due to polarization. Based on various synapse device characteristics, we have estimated the pattern recognition accuracy of MNIST handwritten digits and CIFAR-10 datasets. We have confirmed that synapse device characteristics directly affect the pattern recognition accuracy of ANNs. In order to simultaneously satisfy all the requirements of synapse devices, it is necessary to develop new technology capable of controlling the movement of oxygen vacancies and metal ions at the atomic scale. Considering the limited synapse characteristics of current 2-terminal RRAM devices, hardware ANNs capable of only off-chip training can be constructed by optimizing the current RRAM devices by limiting the bit number. A 3-terminal synapse device or a device based on a new operation principle should be developed as an alternative for on-chip training applications.

Achievement of Reactor-Relevant Performance in Negative Triangularity Shape in the DIII-D Tokamak

Plasma discharges with a negative triangularity (δ=-0.4) shape have been created in the DIII-D tokamak with a significant normalized beta (β_{N}=2.7) and confinement characteristic of the high confinement mode (H_{98y2}=1.2) despite the absence of an edge pressure pedestal and no edge localized modes (ELMs). These inner-wall-limited plasmas have a similar global performance as a positive triangularity (δ=+0.4) ELMing H-mode discharge with the same plasma current, elongation and cross sectional area. For cases both of dominant electron cyclotron heating with T_{e}/T_{i}>1 and dominant neutral beam injection heating with T_{e}/T_{i}=1, turbulent fluctuations over radii 0.5<ρ<0.9 were reduced by 10-50% in the negative triangularity shape compared to the matching positive triangularity shape, depending on the radius and conditions.

Calcium-dependent, non-apoptotic, large plasma membrane bleb formation in physiologically stimulated mast cells and basophils

Large membrane derangements in the form of non-detaching blebs or membrane protrusions occur in a variety of cell stress and physiological situations and do not always reflect apoptotic processes. They have been studied in model mast cells under conditions of cell stress, but their potential physiological relevance to mast cell function and formation in primary mast cells or basophils have not been addressed. In the current study, we examine the large, non-detaching, non-apoptotic, membrane structures that form in model and primary mast cells under conditions of stimulation that are relevant to allergy, atopy and Type IV delayed hypersensitivity reactions. We characterized the inflation kinetics, dependency of formation upon external free calcium and striking geometric consistency of formation for large plasma membrane blebs (LPMBs). We describe that immunologically stimulated LPMBs in mast cells are constrained to form in locations where dissociation of the membrane-associated cytoskeleton occurs. Mast cell LPMBs decorate with wheat germ agglutinin, suggesting that they contain plasma membrane (PM) lectins. Electrophysiological capacitance measurements support a model where LPMBs are not being formed from internal membranes newly fused into the PM, but rather arise from stretching of the existing membrane, or inflation and smoothing of a micro-ruffled PM. This study provides new insights into the physiological manifestations of LPMB in response to immunologically relevant stimuli and in the absence of cell stress, death or apoptotic pathways.

Turbulence measurements on the high and low magnetic field side of the DIII-D tokamak

In this paper, we address the challenging question of measuring turbulence levels on the high magnetic field side (HFS) of tokamak plasmas. Although turbulence measurements on the HFS can provide a stringent constraint for the turbulence model validation, to date only low magnetic field side (LFS) measured turbulence has been used in validation studies. To address this issue, an eight channel Correlation Electron Cyclotron Emission (CECE) system at DIII-D was modified to probe both LFS and HFS. In contrast to the second harmonic extraordinary mode electron cyclotron resonance emission that is typically used in CECE, we show that it is possible to probe the HFS using fundamental O-mode electron cyclotron resonance emission. The required hardware modifications for the HFS measurements are presented here, and the potential issues in this measurement are discussed.

A free-standing wire scattering technique to monitor calibration variations of the DIII-D density profile reflectometer

Real-time phase calibration of the ITER profile reflectometer is essential due to the long plasma duration and expected waveguide path length changes during a discharge. Progress has been recently made in addressing this issue by employing a phase calibration technique on DIII-D that monitors calibration variations that occur during each plasma discharge. By installing a thin free-standing metallic wire (1 mm diameter) near the end of the overmoded waveguide transmission system (oriented perpendicular to the waveguide axis), the round-trip phase shift from the wire is detected simultaneously with the plasma phase shifts. Variations in the reflectometer round trip path length (∼26 m) are then calculated after each DIII-D plasma discharge, allowing the calibration phase to be accurately monitored and updated. The round-trip reflectometer path length is observed to vary by ∼3 mm (root mean square value) during a typical DIII-D discharge. Using the variations in calibration phase, the density profile measurement accuracy can be improved. Since the wire retro-reflected power is ∼0.01 of the plasma signal, minimal effect is observed on the reflected signal from the plasma. Importantly, through a suitable choice in wire diameter, the calibration signal can be made approximately independent of the V-band reflectometer launch polarization. This is particularly important on DIII-D since orthogonal X- and O-mode polarized beams are coupled into the same transmission waveguide and launch antenna.

Impact of a (poly)phenol-rich extract from the brown algae Ascophyllum nodosum on DNA damage and antioxidant activity in an overweight or obese population: a randomized controlled trial

Background

Epidemiologic evidence suggests that a diet rich in (poly)phenols has beneficial effects on many chronic diseases. Brown seaweed is a rich source of (poly)phenols.

Objective

The aim of this study was to investigate the bioavailability and effect of a brown seaweed (Ascophyllum nodosum) (poly)phenol extract on DNA damage, oxidative stress, and inflammation in vivo.

Design

A randomized, double-blind, placebo-controlled crossover trial was conducted in 80 participants aged 30-65 y with a body mass index (in kg/m2) ≥25. The participants consumed either a 400-mg capsule containing 100 mg seaweed (poly)phenol and 300 mg maltodextrin or a 400-mg maltodextrin placebo control capsule daily for an 8-wk period. Bioactivity was assessed with a panel of blood-based markers including lymphocyte DNA damage, plasma oxidant capacity, C-reactive protein (CRP), and inflammatory cytokines. To explore the bioavailability of seaweed phenolics, an untargeted metabolomics analysis of urine and plasma samples after seaweed consumption was determined by ultra-high-performance liquid chromatography-high-resolution mass spectrometry.

Results

Consumption of the seaweed (poly)phenols resulted in a modest decrease in DNA damage but only in a subset of the total population who were obese. There were no significant changes in CRP, antioxidant status, or inflammatory cytokines. We identified phlorotannin metabolites that are considered potential biomarkers of seaweed consumption including pyrogallol/phloroglucinol-sulfate, hydroxytrifurahol A-glucuronide, dioxinodehydroeckol-glucuronide, diphlorethol sulfates, C-O-C dimer of phloroglucinol sulfate, and C-O-C dimer of phloroglucinol.

Conclusions

To the best of our knowledge, this work represents the first comprehensive study investigating the bioactivity and bioavailability of seaweed (poly)phenolics in human participants. We identified several potential biomarkers of seaweed consumption. Intriguingly, the modest improvements in DNA damage were observed only in the obese subset of the total population. The subgroup analysis should be considered exploratory because it was not preplanned; therefore, it was not powered adequately. Elucidation of the biology underpinning this observation will require participant stratification according to weight in future studies. This trial was registered at clinicaltrials.gov as NCT02295878.

Animatronic soft robots by additive folding

This paper presents a new class of animatronic soft robots created by a desktop fabrication mechanism called additive folding. In this method, two-dimensional (2D) slices are threaded by multiple strings, accordion-folded by flexure hinges and finally stacked into a predefined three-dimensional (3D) structure. As the 3D assembly of the slices is controlled by embedded strings, it becomes an animatronic soft robot that moves like a biological creature and that shows life-like movements. We create a computational design algorithm that takes as input a desired 3D geometry of the robot, and that produces a 2D surface with built-in folds and string-based actuators. This paper describes the entire robot design process and demonstrates various animatronic motions, highlighting the vision of desktop fabrication technology and its potential applications in animatronics and robotic art.

Development and validation of algorithms for the detection of statin myopathy signals from electronic medical records

The purpose of this study was to develop and validate sensitive algorithms to detect hospitalized statin-induced myopathy (SIM) cases from electronic medical records (EMRs). We developed four algorithms on a training set of 31,211 patient records from a large tertiary hospital. We determined the performance of these algorithms against manually curated records. The best algorithm used a combination of elevated creatine kinase (>4× the upper limit of normal (ULN)), discharge summary, diagnosis, and absence of statin in discharge medications. This algorithm achieved a positive predictive value of 52-71% and a sensitivity of 72-78% on two validation sets of >30,000 records each. Using this algorithm, the incidence of SIM was estimated at 0.18%. This algorithm captured three times more rhabdomyolysis cases than spontaneous reports (95% vs. 30% of manually curated gold standard cases). Our results show the potential power of utilizing data and text mining of EMRs to enhance pharmacovigilance activities.

A novel technique for real-time estimation of edge pedestal density gradients via reflectometer time delay data

A new model-based technique for fast estimation of the pedestal electron density gradient has been developed. The technique uses ordinary mode polarization profile reflectometer time delay data and does not require direct profile inversion. Because of its simple data processing, the technique can be readily implemented via a Field-Programmable Gate Array, so as to provide a real-time density gradient estimate, suitable for use in plasma control systems such as envisioned for ITER, and possibly for DIII-D and Experimental Advanced Superconducting Tokamak. The method is based on a simple edge plasma model with a linear pedestal density gradient and low scrape-off-layer density. By measuring reflectometer time delays for three adjacent frequencies, the pedestal density gradient can be estimated analytically via the new approach. Using existing DIII-D profile reflectometer data, the estimated density gradients obtained from the new technique are found to be in good agreement with the actual density gradients for a number of dynamic DIII-D plasma conditions.

A frequency tunable, eight-channel correlation ECE system for electron temperature turbulence measurements on the DIII-D tokamak

A new eight-channel correlation electron cyclotron emission diagnostic has recently been installed on the DIII-D tokamak to study both turbulent and coherent electron temperature fluctuations under various plasma conditions and locations. This unique system is designed to cover a broad range of operation space on DIII-D (1.6-2.1 T, detection frequency: 72-108 GHz) via four remotely selected local oscillators (80, 88, 96, and 104 GHz). Eight radial locations are measured simultaneously in a single discharge covering as much as half the minor radius. In this paper, we present design details of the quasi-optical system, the receiver, as well as representative data illustrating operation of the system.

Renal functional outcomes are not adversely affected by selective angioembolization following percutaneous nephrolithotomy

Objective

Selective angioembolization (SAE) effectively diagnoses and treats iatrogenic vascular complications following percutaneous nephrolithotomy (PCNL).

Methods

We retrospectively reviewed 1329 consecutive PCNLs and identified patients who underwent SAE following PCNL with at least 12-month follow-up. Estimated glomerular filtration rate (eGFR) was calculated for all patients preoperatively, postoperatively and at last follow-up. A 1:2 matched cohort analysis was performed.

Results

Twenty-three patients underwent SAE and matched to 46 controls. There was no statistically significant difference in preoperative, postoperative, and follow-up eGFR when comparing patients who underwent SAE and those with an uneventful course.

Conclusion

Long-term eGFR is comparable in patients who undergo uncomplicated PCNL and those requiring SAE.

Measurement of electron temperature fluctuations using a tunable correlation electron cyclotron emission system on Alcator C-Mod

A tunable correlation electron cyclotron (CECE) system was recently installed on the Alcator C-Mod tokamak to provide local, quantitative measurement of electron temperature fluctuations in the tokamak core. This system represents a significant upgrade from the original CECE system, expanding the measurement capabilities from 4 to 8 total channels, including 2 remotely tunable YIG filters (6-18 GHz; 200 MHz bandwidth). Additional upgrades were made to the optical system to provide enhanced poloidal resolution and allow for measurement of turbulent fluctuations below kθρs < 0.3. These expanded capabilities allow for single shot measurement of partial temperature fluctuation profiles in the region ρ = 0.7 - 0.9 (square root of normalized toroidal flux) in a wide variety of plasma conditions. These measurements are currently being used to provide stringent tests of the gyrokinetic model in ongoing model validation efforts. Details of the hardware upgrades, turbulent fluctuation measurements, and ongoing comparisons with simulations are presented.

Isolated adrenal cryptococcosis, diagnosed by fine-needle aspiration biopsy: a case report

This report documents a case of isolated adrenal gland cryptococcosis without the often reported component of concomitant meningitis or Addison's disease in an immune competent patient. Furthermore, both the patient's lung cancer and adrenal infection with cryptococcus were incidentally discovered during work-up for syncope in the setting of hyponatremia. This case also underscores the diagnostic value of fine-needle aspiration biopsy in this unusual presentation.

Design of a correlation electron cyclotron emission diagnostic for Alcator C-Mod

A correlation electron cyclotron emission (CECE) diagnostic has been installed in Alcator C-Mod. In order to measure electron temperature fluctuations, this diagnostic uses a spectral decorrelation technique. Constraints obtained with nonlinear gyrokinetic simulations guided the design of the optical system and receiver. The CECE diagnostic is designed to measure temperature fluctuations which have k(θ) ≤ 4.8 cm(-1) (k(θ)ρ(s) < 0.5) using a well-focused beam pattern. Because the CECE diagnostic is a dedicated turbulence diagnostic, the optical system is also flexible, which allows for various collimating lenses and antenna to be used. The system overview and the demonstration of its operability as designed are presented in this paper.

Life-threatening postoperative hemorrhage from hepatic artery pseudoaneurysm successfully treated by transcatheter embolization in a 5-year-old

Upper gastrointestinal bleeding caused by a pseudoaneurysm after hepatobiliary operation is well described in adults. This can be successfully treated with transcatheter embolization under angiographic guidance. We report a case of massive upper gastrointestinal bleeding in a 5-year-old boy secondary to a pseudoaneurysm of the right hepatic artery after choledochal cyst excision. A coil embolization successfully treated this life-threatening event and spared the child, the morbidity of a challenging gastrointestinal and vascular reconstruction. Use of percutaneous interventional technique to treat this rare complication of choledochal cyst excision has not been previously described in the pediatric surgical literature. Transcatheter embolization of a pseudoaneurysm may be a safe and less morbid treatment alternative for this surgical complication even in the pediatric population.

Phase Characterization and Morphology Control of Electrospun Nanofibers of Pani/Pmma Blends

Electrospinning derived from electro spraying is a process by which sub-micron polymer fibers can be produced using an electrostatically driven jet of polymer solution. The fibers are collected as non-woven mat and offer a high surface to volume ratio. Polyaniline is an organic conducting polymer and can be used to fabricate conducting nano fibers by blending with suitable polymers like poly methyl methacrylate. In this present work we have explored the effects of electrospinning parameters on the formation of PANI/PMMA fibers and the phase morphology of the electrospun fibers using advanced electron microscopy and scanning probe microscopy techniques.

Probiotic potential of Staphylococcus hominis MBBL 2-9 as anti-Staphylococcus aureus agent isolated from the vaginal microbiota of a healthy woman

AIMS

To isolate and characterize an antagonist for use as probiotic agent in the biocontrol of Staphylococcus aureus.

METHODS AND RESULTS

Bacteria that exhibited antimicrobial activity against Gram-positive bacteria including Staph. aureus were isolated from 12 healthy women, with Staphylococcus hominis MBBL 2-9 showing the strongest activity. The bacteriocin produced by Staph. hominis MBBL 2-9 was purified by 60% ammonium sulfate saturation, ultrafiltration, HLB cartridge and reverse-phase HPLC. The molecular weight was estimated as 2038.2 Da by MALDI-TOF mass spectrometry. The antagonist survived up to 2 h in artificial gastric juice (pH 2.5) and grew in the presence of 1% porcine bile extract. In addition, Staph. hominis MBBL 2-9 adhered effectively to HT-29 epithelial cell line.

CONCLUSION

Staphylococcus hominis MBBL 2-9 exhibited desirable probiotic traits such as acid tolerance, bile resistance and adherence to epithelial cell line. The bacterium also produced a bacteriocin with unique molecular weight and high antimicrobial activity similar to traditional antibiotics.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first report of a bacteriocin-producing Staph. hominis MBBL 2-9 that has potential for use as a probiotic agent against Staph. aureus.

HGS-ETR1, a fully human TRAIL-receptor 1 monoclonal antibody, induces cell death in multiple tumour types in vitro and in vivo

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in a variety of tumour cells through activation of TRAIL-R1 and TRAIL-R2 death signalling receptors. Here, we describe the characterisation and activity of HGS-ETR1, the first fully human, agonistic TRAIL-R1 mAb that is being developed as an antitumour therapeutic agent. HGS-ETR1 showed specific binding to TRAIL-R1 receptor. HGS-ETR1 reduced the viability of multiple types of tumour cells in vitro, and induced activation of caspase 8, Bid, caspase 9, caspase 3, and cleavage of PARP, indicating activation of TRAIL-R1 alone was sufficient to induce both extrinsic and intrinsic apoptotic pathways. Treatment of cell lines in vitro with HGS-ETR1 enhanced the cytotoxicity of chemotherapeutic agents (camptothecin, cisplatin, carboplatin, or 5-fluorouracil) even in tumour cell lines that were not sensitive to HGS-ETR1 alone. In vivo administration of HGS-ETR1 resulted in rapid tumour regression or repression of tumour growth in pre-established colon, non-small-cell lung, and renal tumours in xenograft models. Combination of HGS-ETR1 with chemotherapeutic agents (topotecan, 5-fluorouracil, and irinotecan) in three independent colon cancer xenograft models resulted in an enhanced antitumour efficacy compared to either agent alone. Pharmacokinetic studies in the mouse following intravenous injection showed that HGS-ETR1 serum concentrations were biphasic with a terminal half-life of 6.9–8.7 days and a steady-state volume of distribution of approximately 60 ml kg⁻¹. Clearance was 3.6–5.7 ml⁻¹ day⁻¹ kg⁻¹. These data suggest that HGS-ETR1 is a specific and potent antitumour agent with favourable pharmacokinetic characteristics and the potential to provide therapeutic benefit for a broad range of human malignancies.

High energy gain of trapped electrons in a tapered, diffraction-dominated inverse-free-electron laser

Energy gain of trapped electrons in excess of 20 MeV has been demonstrated in an inverse-free-electron-laser (IFEL) accelerator experiment. A 14.5 MeV electron beam is copropagated with a 400 GW CO2 laser beam in a 50 cm long undulator strongly tapered in period and field amplitude. The Rayleigh range of the laser, approximately 1.8 cm, is much shorter than the undulator length yielding a diffraction-dominated interaction. Experimental results on the dependence of the acceleration on injection energy, laser focus position, and laser power are discussed. Simulations, in good agreement with the experimental data, show that most of the energy gain occurs in the first half of the undulator at a gradient of 70 MeV/m and that the structure in the measured energy spectrum arises because of higher harmonic IFEL interaction in the second half of the undulator.

The dMRP/CG6214 gene of Drosophila is evolutionarily and functionally related to the human multidrug resistance-associated protein family

ATP-binding cassette (ABC) transporters are involved in the transport of substrates across biological membranes and are essential for many cellular processes. Of the fifty-six Drosophila ABC transporter genes only white, brown, scarlet, E23 and Atet have been studied in detail. Phylogenetic analyses identify the Drosophila gene dMRP/CG6214 as an orthologue to the human multidrug-resistance associated proteins MRP1, MRP2, MRP3 and MRP6. To study evolutionarily conserved roles of MRPs we have initiated a characterization of dMRP. In situ hybridization and Northern analysis indicate that dMRP is expressed throughout development and appears to be head enriched in adults. Functional studies indicate that DMRP is capable of transporting a known MRP1 substrate and establishes DMRP as a high capacity ATP-dependent, vanadate-sensitive organic anion transporter.

Safety and pharmacokinetics of intravitreal 2-methoxyestradiol implants in normal rabbit and pharmacodynamics in a rat model of choroidal neovascularization

Choroidal neovascularization (CNV) is the leading cause of severe vision loss associated with age-related macular degeneration. As the pathogenesis of CNV formation is better understood, mechanism-based therapies, including the use of antiangiogenesis inhibitors, have been investigated. 2-methoxyestradiol (2ME2), an endogenous metabolite of estradiol, has been shown in the chick allantoic membrane model and the corneal micropocket assay to have antiangiogenic properties. The authors sought to determine the safety and pharmacokinetics of sustained-release intravitreal 2ME2 implants in normal rabbit and their efficacy in a rat model of CNV. 2ME2 implants were constructed using two designs: implant A, a silicone-based reservoir implant for the rabnbit eye, and implant B, a microimplant matrix design for the rat eye. In vitro release rates of both implants were determined. New Zealand white (NZW) rabbits had implant A placed in the vitreous cavity of one eye and the ocular toxicity was evaluated by clinical examination, serial electroretinography (ERG), and histopathology over a 28 week period. The steady state clearance of 2ME2 in the rabbit eye was calculated from in vivo release rates divided by steady state vitreous concentrations. A CNV model in the Brown-Norway rat was performed by injecting an adenoviral vector encoding human vascular endothelial growth factor in the subretinal space. Following the injection, a 2ME2 or sham (no drug) microimplant was placed in the vitreous cavity. Animals were killed over a 3 week period and the eyes examined for CNV by histopathology. Results showed that following a short burst, the release rate of implant A followed zero-order kinetics, typical of reservoir devices, and the cumulative release of implant B was proportional to the square root of time, as expected for a matrix delivery device. The safety studies in normal rabbit showed no ocular toxicities by clinical examination, ERG, and histopathology. Pharmacokinetic evaluation in the rabbit showed mean 2ME2 vitreous levels within the therapeutic range for the inhibition of endothelial cell proliferation. The experimental rat model showed a significant reduction in CNV in eyes treated with the 2ME2 implant. In conclusion, sustained-release 2ME2 intravitreal implants, which can be designed to deliver potentially therapeutic vitreous levels of 2ME2 for an extended period of time, appeared to be safe in normal rabbit and effective in a rat model of CNV. Sustained-release 2ME2 intravitreal implants may hold promise in the treatment of recurrent CNV refractory to standard therapy.

Pharmacokinetics and toxicity of intravitreal chemotherapy for primary intraocular lymphoma

OBJECTIVE

To investigate the pharmacokinetics and toxicity of intravitreal chemotherapeutic agents in the rabbit eye for the potential treatment of primary intraocular lymphoma and other intraocular malignancies.

METHODS

The ocular pharmacokinetics of intravitreal methotrexate sodium (400 microg) was studied in 10 New Zealand white rabbits, and a single-compartment, first-order elimination model was used to calculate the drug half-life. With the use of these data, a treatment schedule using serial injections of intravitreal methotrexate and single injections of fluorouracil and dexamethasone sodium phosphate was developed. This schedule was studied in 4 New Zealand white rabbits to explore the combined toxicity of these agents.

RESULTS

Methotrexate vitreous levels, following a 400-microg intravitreal injection, remained therapeutic (>0.5 microM) in the rabbit eye for 48 to 72 hours. Intravitreal methotrexate, combined with fluorouracil and dexamethasone, showed no evidence of drug toxicity as determined by electroretinography and histopathologic examination.

CONCLUSIONS

A treatment schedule for primary intraocular lymphoma consisting of methotrexate intravitreal injections every 48 to 72 hours provides therapeutic drug concentrations in the vitreous and, in combination with fluorouracil and dexamethasone, appears to be safe in the rabbit eye.

CLINICAL RELEVANCE

Although responsive to conventional chemotherapy or radiotherapy, recurrence of ocular involvement with primary central nervous system lymphoma occurs in more than 50% of treated cases. Anecdotal reports of the use of intravitreal chemotherapy for primary intraocular lymphoma have been encouraging. However, animal data on the pharmacokinetics and toxicity of combined intravitreal agents for the treatment of this disease are lacking.

Finite element model of antibody penetration in a prevascular tumor nodule embedded in normal tissue

We have developed a pharmacokinetic model for monoclonal antibodies (mAb) to aid in investigating protocols for targeting small primary tumors or sites of metastatic disease. The model describes the uptake of systemically-administered antibody by a prevascular spherical tumor nodule embedded in normal tissue. The model incorporates plasma kinetics, transcapillary transport, interstitial diffusion, binding reactions, and lymphatic clearance. Antigen internalization can easily be incorporated. Simulations obtained from a three-dimensional finite element analysis are used to assess errors in predictions from earlier models in which the influence of the normal tissue was collapsed into a boundary condition at the tumor surface. The model employing a Dirichlet boundary condition substantially overpredicted the mean total tumor mAb concentration at all times. Although the model with a concentration-dependent flux (composite) boundary condition underpredicted mAb concentration, the discrepancy with finite element results is only notable at early times. Sensitivity analyses were performed on mAb dose and on the coefficients for mAb diffusion in the tissue regions, since reported antibody diffusivity values have varied over 30-fold. The results of the study suggest that mAb diffusivity and mAb binding site density in tumors should have major influences on optimizing doses and scheduling of mAb administration in tumor targeting protocols.

Measurement of in situ hybridization

Hybridization of labeled specific molecular probes to nucleic acids in tissues allows geometric and functional location of gene expression or of foreign genome sequences. Estimates of amounts and location of target nucleic acid sequence can be made with phosphor storage imaging and molecular controls.

Computational models of antibody-based tumor imaging and treatment protocols

We present improved computational models for investigating monoclonal antibody-based protocols for diagnostic imaging and therapy of solid tumors. Our earlier models used a boundary condition (Dirichlet) that specified concentrations of diffusing molecular species at the interface between a prevascular tumor nodule and surrounding normal tissue. Here we introduce a concentration-dependent flux boundary condition with finite rates of diffusion in the normal tissue. We then study the effects of this new condition on the tumor's temporal uptake and spatial distribution of radiolabeled targeting agents. We compare these results to ones obtained with the Dirichlet boundary condition and also conduct parameter sensitivity analyses. Introducing finite diffusivity for any molecular species in normal tissue retards its delivery to and removal from the tumor nodule. Effects are protocol- and dose regimen-dependent: generally, however, mean radionuclide concentration and tumor-to-blood ratio declined, whereas relative exposure and mean residence time increased. Finite diffusivity exacerbates the negative effects of antigen internalization. Also, the sensitivity analyses show that mean concentration and tumor-to-blood ratio are quite sensitive to transcapillary permeability and lymphatic efflux values, yet relatively insensitive to precise values of diffusion coefficients. Our analysis underscores that knowledge of antigen internalization rates and doses required to saturate antigen in the tumor will be important for exploiting antibody-based imaging and treatment approaches.

Optical scattering (TAOS) by tire debris particles: preliminary results

Tire debris particles from low severity laboratory wear tests have been investigated by the TAOS optical scattering facility at Yale University. The incident wavelength is 532 nm. After the TAOS event some particle samples have been imaged by a scanning electron microscope and microanalyzed. The TAOS intensity patterns recorded within a solid angle in the backward sector have been processed by cluster analysis and compared with the patterns computed by a T-matrix code. Preliminary agreement has been found between TAOS data and the particle models (size, shape, refractive index). The purpose of the investigation is to obtain signatures of the material, based on its TAOS pattern.

Association of Trk neurotrophin receptors with components of the cytoplasmic dynein motor

Nerve growth factor (NGF) initiates its trophic effects by long-range signaling through binding, internalization, and transport of a ligand-receptor complex from the axon terminal to the cell body. However, the mechanism by which retrograde transport of NGF takes place has not been elucidated. Here we describe an interaction between the Trk receptor tyrosine kinase and a 14 kDa light chain of cytoplasmic dynein. After transfection in human embryonic kidney 293 cells, this 14 kDa dynein light chain was found to bind to TrkA, TrkB, and TrkC receptors. Mapping experiments indicated that the 14 kDa dynein light chain binds to the distal region of the TrkA juxtamembrane domain. Coimmunoprecipitation experiments in vivo indicate that Trk receptors are in a complex with the 14 kDa light chain and 74 kDa intermediate chain of dynein. Confirming the physiological relevance of this association, a marked accumulation of Trk with the 14 kDa and the 74 kDa dynein components was observed after ligation of the sciatic nerve. The association of Trk receptors with components of cytoplasmic dynein suggests that transport of neurotrophins during vesicular trafficking may occur through a direct interaction of the Trk receptor with the dynein motor machinery.

Pharmacokinetics and immunological effects of exogenously administered recombinant human B lymphocyte stimulator (BLyS) in mice

B lymphocyte stimulator (BLyS; also known as TNFSF20, BAFF, TALL-1, zTNF4, and THANK), a tumor necrosis factor ligand family member, has recently been identified as a factor that promotes expansion and differentiation of the B cell population, leading to increases in serum immunoglobulin levels. Here, pharmacokinetic parameters for BLyS administered i.v. and s.c. to mice are described, and the effects of different dosing regimens on serum and salivary immunoglobulin levels as well as splenic cell populations are reported. The pharmacokinetics of BLyS following i.v. injection are monophasic with a half-life of 160 min, a clearance of 0.22 ml/min-kg, and a volume of distribution of 53 ml/kg. Systemic administration of BLyS to mice resulted in increased serum IgG, IgA, IgM, and IgE and salivary IgA as well as splenic B cell population expansion and differentiation. The i.v. and s.c. routes of administration were pharmacologically equivalent, even though s.c. bioavailability of BLyS is only 25%. BLyS (s.c.) dramatically elevated serum IgG and IgA levels, and the duration of the responses after cessation of treatment (t(1/2) = 4.4 and 1.3 days, respectively) are similar to the half-lives of endogenous IgG and IgA in mice. The IgM response is more modest than that of IgG and IgA but lasts longer (t(1/2) = 7.0 days) than the half-life of endogenous IgM. A linear pharmacodynamic response was identified between days of dosing x log(dose), and increases in serum IgG, IgA, and IgM indicating that the response is more sensitive to the duration of dosing than to the cumulative dose. The implications of these findings for therapeutic administration of BLyS are discussed.

Cell-autonomous requirement of the USP/EcR-B ecdysone receptor for mushroom body neuronal remodeling in Drosophila

Neuronal process remodeling occurs widely in the construction of both invertebrate and vertebrate nervous systems. During Drosophila metamorphosis, gamma neurons of the mushroom bodies (MBs), the center for olfactory learning in insects, undergo pruning of larval-specific dendrites and axons followed by outgrowth of adult-specific processes. To elucidate the underlying molecular mechanisms, we conducted a genetic mosaic screen and identified one ultraspiracle (usp) allele defective in larval process pruning. Consistent with the notion that USP forms a heterodimer with the ecdysone receptor (EcR), we found that the EcR-B1 isoform is specifically expressed in the MB gamma neurons, and is required for the pruning of larval processes. Surprisingly, most identified primary EcR/USP targets are dispensable for MB neuronal remodeling. Our study demonstrates cell-autonomous roles for EcR/USP in controlling neuronal remodeling, potentially through novel downstream targets.

Characterization of the regulatory elements controlling neuronal expression of the A-isoform of the ecdysone receptor gene of Drosophila melanogaster

During the development of the adult central nervous system (CNS) of the fruitfly Drosophila melanogaster, the A-isoform of the ecdysone receptor (EcR-A), a typical nuclear hormone receptor, is expressed at high levels in the Type II neurons, a set of neurons that die shortly after the emergence of the adult. To understand the role that transcriptional regulation of nuclear receptor genes plays in CNS development, we have dissected the region controlling the transcription of EcR-A by analyzing the ability of this region to drive the expression of reporter genes in transgenic animals. These analyses have demonstrated that the Type II neurons are a heterogeneous collection of neurons that utilize different regulatory elements to coordinate the expression of the same transcript.

Targeting of transferrin receptors in nude mice bearing A431 and LS174T xenografts with [18F]holo-transferrin: permeability and receptor dependence

The goal of this study was to investigate whether 18F-labeled transferrin (Tf), which has a molecular weight (Mr) of approximately 79,000, binds to Tf receptor sites in tumors in a specific manner within the time frame commensurate with the half-life of 18F (109.7 min). We have previously shown that [18F]holo-Tf ([18F]Tf) maintains all properties of native Tf in vitro and that it can specifically target liver Tf receptor sites in vivo.

METHODS

The distribution of [18F]Tf, using [18F]albumin (Alb) or [14C]Alb as a control, was studied over a 6-h period in nude mice bearing LS174T and A431 xenografts of a high- and low-permeability tumor, respectively.

RESULTS

Measurements of Tf receptor concentration in the tumor extracts suggest similar binding capacities. In vivo, liver uptake values were higher for [18F]Tf than for both [18F]Alb and [14C]Alb throughout the study, indicating specific binding. In contrast, tumor Tf uptake values remained below those of the Alb tracers, and tumor-to-blood ratios of [18F]Tf in each xenograft increased in parallel with those of the Alb tracers. The permeabilities of [14C]Alb and [18F]Tf in LS174T were calculated to be 1.29+/-0.49 and 1.03+/-0.38 microL/min/g (mean +/- SD), respectively, whereas the permeabilities of the two tracers in A431 were 0.79+/-0.24 and 0.44+/-0.04 microL/min/g. Pharmacokinetic modeling of the data using these permeabilities and the high plasma and extracellular concentrations of endogenous Tf showed that the observed uptake values in the two xenografts are consistent with a non-receptor-mediated distribution. In the liver, the absence of permeability barriers yields specific [18F]Tf binding to receptors compared with the [14C]Alb control, within 5 min after injection.

CONCLUSION

Receptor-mediated accumulation of [18F]Tf in tumor xenografts is impaired by rate-determining permeability and competition from endogenous Tf and is not achieved in a time frame of 6 h.

Reversible nephrotoxicity of onconase and effect of lysine pH on renal onconase uptake

PURPOSE

To examine the histopathology of the kidney in mice following repeated injections of the antitumor drug onconase, and to determine whether lysine, which reportedly blocks kidney uptake of other basic proteins, blocks the high renal uptake of onconase.

METHODS

Mice received repeated intraperitoneal onconase injections over 3 weeks. Kidneys were examined by light microscopy after 1 week, 3 weeks, and 5 weeks (2 weeks after cessation of injections) and compared to kidneys from animals receiving a similar schedule of PBS injections. Renal uptake of radioiodinated onconase was measured in animals receiving intraperitoneal injections of lysine solutions of acidic and neutral pH given at -30, 0 and + 5 min relative to intravenous onconase injection. Renal onconase uptake was also measured in animals made metabolically acidotic by ingestion of ammonium chloride, arginine chloride or lysine dihydrochloride from the drinking water.

RESULTS

Onconase caused acute moderate multifocal proximal renal tubular necrosis, and this toxicity was reversed by 2 weeks after drug withdrawal. Intraperitoneal injections of lysine dihydrochloride in PBS (pH 1.5) reduced renal onconase uptake at 15 min from 67.9+/-13.4% to 17.0+/-3.8% of the injected dose without affecting the plasma concentration and also reduced the fraction of degraded onconase in the urine. However, neutral solutions of lysine dihydrochloride at pH 7.4 or lysine acetate at pH 7.1 were ineffective at blocking renal onconase uptake. Furthermore, renal onconase uptake was minimally or not affected by a state of metabolic acidosis.

CONCLUSIONS

Proximal tubular toxicity of onconase was reversible. Renal onconase uptake was blocked by lysine at pH 1.5 but not at neutral pH.