Height-based formulas for predicting intravascular length of tunnelled neck central venous catheter in paediatric population

INTRODUCTION

Central venous catheter (CVC) placement is commonly performed in children. We aim to develop simple formulas to predict CVC intravascular length to minimise radiation exposure associated with the procedure.

METHODS

124 paediatric patients who received tunnelled neck CVCs and subsequent CT thorax at Hong Kong Children's Hospital from January 2020 to July 2022 were reviewed retrospectively. Formula development cohorts were subdivided by insertion sites-9 right external jugular vein (REJV), 41 right internal jugular vein (RIJV), 14 left external jugular vein (LEJV), 10 left internal jugular vein (LIJV). Using measurements from CT by two radiologists, formulas predicting the CVC intravascular length based on height and insertion sites were developed using a linear regression model. These formulas were tested with validation cohorts (10 randomly selected cases in REJV and RIJV groups respectively). Validation cohorts were not available for LEJV and LIJV groups due to small sample sizes.

RESULT

The goodness-of-fit (R^2) of all formulas are above 0.8. In the validation cohorts, the REJV formula was predictive of intravascular CVC length within 1 cm in 70% of CVC with mean absolute difference of 0.63 cm (SD 0.48 cm), and the RIJV formula was predictive of intravascular CVC length within 1 cm in 80% of CVC with mean absolute difference of 0.67 cm (SD 0.53 cm).

CONCLUSION

Intravascular CVC length can be estimated using simple formulas based on height and insertion sites. Further prospective validation of the LEJV and LIJV formulas is needed.

Regional inequality of socioeconomic status and the prevalence of hypertension between rural and urban areas

Background

Lower socioeconomic status (SES) is associated with greater burdens of cardiovascular disease in a community. The regional disparity of SES may result in an uneven distribution of hypertension (HTN) by a region. This study aims to analyze the regional disparity in the SES and HTN burden between rural and urban areas of the Korea.

Methods

We used data from the Korea National Health and Nutrition Examination Survey (KNHANES) V (2010–2012), VI (2013–2015), and VII (201–2018). We analyzed 11,206 and 1739 subjects from Seoul metropolitan and rural area (Gangwon province), respectively. We compared socioeconomic characteristics, the distribution of HTN between two regions. Finally, we performed a multivariate logistic regression adjusting for traditional CV risk factors and SES status to examine differences in the prevalence of HTN.

Results

Subjects in Gangwon province were older than Seoul (54.6±0.4 vs 49.4±0.2 years old, p<0.001). The proportions of subjects with low economic status and low education level were significantly higher in Gangwon province compared to Seoul (low economic status; 25.6 vs 14.4%, p<0.001, low education level; 35.3 vs 16.5%, p<0.001). Mean systolic blood pressure (SBP) was higher in Gangwon compared to Seoul (121.6±0.4 vs 118.1±0.2 mmHg, p<0.001). In the longitudinal trend from KNHANES V to VII, the difference of SBP between the two regions increased (Figure). The age-matched prevalence of HTN was significantly higher in Gangwon compared to Seoul (23.8 vs 21.6%, p<0.05), and the difference of prevalence of HTN by regions longitudinally increased (Figure). In the univariate analysis, the residency in Gangwon was associated with the presence of HTN (reference: Seoul, OR=1.63; 95% CI: 1.45–1.83). In the multivariate logistic regression model, the residency in Gangwon was not associated, however, low economic status and low education level were significantly associated with the presence of HTN (economic status, OR=1.39; 95% CI: 1.17–1.67, education level, OR=1.88; 95% CI: 1.57–2.24).

Conclusion

The SES status was lower and the prevalence of HTN was higher in Gangwon compared to Seoul. The burden of HTN longitudinally increased in Gangwon, but not in Seoul. The poor SES was significantly associated with HTN. It suggests that the inequalities of SES in Gangwon may contribute to the increasing prevalence of HTN. The regional and individual disparity of SES should be considered in the establishment of public health strategies for HTN.

Funding Acknowledgement

Type of funding sources: None.

Site-Specific and Coherent Manipulation of Individual Qubits in a 1D Optical Lattice with a 532-nm Site Separation

We demonstrate gate operations on a single qubit at a specific site without perturbing the coherence of an adjacent qubit in a 1D optical lattice when the site separation is only 532 nm. Three types of spin rotations are performed on the target qubit with fidelities between 0.88±0.05 and 0.99±0.01, whereas the superposition state of the adjacent one is preserved with fidelities between 0.93±0.04 and 0.97±0.04. The qubit is realized by a pair of Zeeman-sensitive ground hyperfine states of a ^{7}Li atom, and each site is identified by its resonance frequency in a magnetic field gradient of 1.6  G/cm. We achieve the site-specific resolving power in the frequency domain by using magic polarization for the lattice beam that allows a Fourier-limited transition linewidth as well as by highly stabilizing the lattice parameters and the ambient conditions. We also discuss a two-atom entanglement scheme using a blockade by cold collisional shifts in a 1D superlattice, for which a coherent manipulation of individual qubits is a prerequisite.

Abstract P6-18-31: PROCLAIM-CX-072: Monotherapy for advanced triple negative breast cancer with skin metastases in a phase 1-2 trial of the PD-L1 probody therapeutic CX-072

Background: Probody™ therapeutics are novel, fully recombinant antibody prodrugs designed to remain relatively inactive in healthy tissue and to be specifically activated by proteases in the tumor microenvironment. In this way, Probody therapeutics may broaden the therapeutic window for effective but potentially toxic anticancer agents. CX-072 is a Probody therapeutic directed against programmed death-ligand 1 (PD-L1) for the treatment of cancer patients. In a first-in-human, open-label, multicenter, dose-escalation, 3+3 design, phase 1-2 study, PROCLAIM-CX-072 (PRObody CLinical Assessment In Man) (NCT03013491), 22 patients were enrolled in the phase 1 dose escalation portion. Twenty patients were evaluable per RECIST v1.1. Three patients had confirmed partial response (15%), including a 39-year-old woman with stage IV triple negative breast cancer (TNBC) treated with 10 mg/kg CX-072 monotherapy whose disease had progressed on one previous line of chemotherapy for metastatic disease. Metastatic sites included extensive nodal disease and skin/chest wall lesions. The tumor was negative for PD-L1 expression, was microsatellite stable, and had a low tumor mutational burden (4 mutations/megabase). Positive results from the phase 1 study suggest that additional exploration of treatment with CX-072 monotherapy in the TNBC patient population is warranted.

Dose expansion trial design: The phase 2 dose expansion part of the PROCLAIM-CX-072 study will include enrollment of TNBC patients with skin metastases. Key inclusion criteria for patients in the TNBC cohort are as follows: naive to immunotherapy (PD-1/PD-L1 and CTLA-4 inhibitors), approved immune checkpoint inhibitor agents not available, histologically confirmed triple negative (estrogen receptor–, progesterone receptor–, and human epidermal growth factor receptor-2–negative cancer per ASCO-CAP guidelines), previously treated with 1 to 3 systemic chemotherapy regimens, and locally advanced and recurrent skin or subcutaneous metastases not suitable for surgical resection or radiotherapy. Patients will receive doses of 10 mg/kg CX-072 intravenously every 2 weeks. Efficacy will be evaluated using RECIST v1.1 and immune-related RECIST criteria. Safety and tolerability will be assessed based on the incidence and severity of adverse events (categorized by NCI CTCAE criteria, v4.03) and relationship to study drug. Other analyses will include pharmacokinetics, incidence of anti-drug antibodies against CX-072, exploratory analysis for immune response, and CX-072 activation in the tumor.

PROBODY is a trademark of CytomX Therapeutics, Inc.

Citation Format: Adams S, Hamilton E, Ott PA, Cho D, Kalinsky K, LoRusso P, Will M, Huels V, Benson B, Murias C, Arkenau H-T. PROCLAIM-CX-072: Monotherapy for advanced triple negative breast cancer with skin metastases in a phase 1-2 trial of the PD-L1 probody therapeutic CX-072 [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-31.

Amplifier for scanning tunneling microscopy at MHz frequencies

Conventional scanning tunneling microscopy (STM) is limited to a bandwidth of a few kHz around DC. Here, we develop, build, and test a novel amplifier circuit capable of measuring the tunneling current in the MHz regime while simultaneously performing conventional STM measurements. This is achieved with an amplifier circuit including a LC tank with a quality factor exceeding 600 and a home-built, low-noise high electron mobility transistor. The amplifier circuit functions while simultaneously scanning with atomic resolution in the tunneling regime, i.e., at junction resistances in the range of giga-ohms, and down towards point contact spectroscopy. To enable high signal-to-noise ratios and meet all technical requirements for the inclusion in a commercial low temperature, ultra-high vacuum STM, we use superconducting cross-wound inductors and choose materials and circuit elements with low heat load. We demonstrate the high performance of the amplifier by spatially mapping the Poissonian noise of tunneling electrons on an atomically clean Au(111) surface. We also show differential conductance spectroscopy measurements at 3 MHz, demonstrating superior performance over conventional spectroscopy techniques. Further, our technology could be used to perform impedance matched spin resonance and distinguish Majorana modes from more conventional edge states.

Barriers to physical activity and healthy diet among breast cancer survivors: A multilevel perspective

Cancer survivors engage in suboptimal levels of health behaviours and report many barriers to health behaviours, but we lack a solid understanding of the different levels of barriers and how they relate to enacted health behaviours. To address these issues, we conducted mixed-method research in 97 breast cancer survivors. Participants' barriers to physical activity (PA) and healthy diet, asked as an open-ended question, were coded as individual-level, social-level, and organisational/environmental-level for each health behaviour. Moderate-to-vigorous PA and fruit and vegetable (F&V) intake were assessed. Most participants perceived at least one PA (72.7%) and diet (64.9%) individual-level barrier (e.g. physical symptoms/injury); only 15.2% (PA) and 15.6% (diet) reported at least one social-level barrier (e.g. family obligations). About 28.8% (PA) and 29.9% (diet) perceived at least one organisational/environmental-level barrier (e.g. job demand, cost of F&V). Survivors perceiving individual-level dietary barriers consumed less F&V (-.65 servings/day) than those not perceiving dietary barriers at this level. Survivors perceiving social-level dietary barriers reported marginally lower F&V intake (-.65 servings/day) than their counterparts. Those perceiving organisational/environmental-level PA barriers reported marginally fewer minutes (-44.30/week) of moderate-to-vigorous PA than their counterparts. Barriers at multiple levels should be addressed to improve health behaviours among breast cancer survivors.

Short-Term Outcomes of ABO-Incompatible Living Donor Kidney Transplantation With Uniform Protocol: Significance of Baseline Anti-ABO Titer

Antibody-mediated rejection (AMR) is one of the major causes of poor outcomes in ABO-incompatible kidney transplantation (ABOi KT). Studies investigating AMR risk factors found that anti-ABO titer is a major issue. However, the significance of antibody titer has been debated. This retrospective study analyzed AMR risk factors in 59 patients who underwent ABOi KT between August 2010 and January 2015. We also analyzed AMR risk factors in recipients with high anti-ABO baseline titers (≥1:64 on dithiothreitol at 37°C phase or ≥1:256 on antihuman globulin phase). The 2-year patient survival rate was 95.8%, and the 2-year graft survival rate was 94.9%. Nine patients (15.3%) experienced clinical (6 of 59 [10.2%]) or subclinical (3 of 59 [5.1%]) AMR. One patient experienced graft loss from hyperacute rejection. AMR risk factor analysis revealed that baseline antibody titer was associated with incidence of AMR. In patients with high baseline titers, low doses of rituximab (200-mg single-dose), an antibody against CD20, was predictive for AMR. Six patients who received pretransplant intravenous immunoglobulin did not experience AMR even when they had high baseline antibody titers. Our results indicate that a high baseline antibody titer affected the incidence of AMR. ABOi KT candidates with high baseline titers need to undergo an intensified preconditioning protocol, including high-dose rituximab (375 mg/m(2)) and intravenous immunoglobulin.

An effective diagnostic strategy for accurate detection of RhD variants including Asian DEL type in apparently RhD-negative blood donors in Korea

BACKGROUND AND OBJECTIVES

The purpose of this study was to provide an effective RHD genotyping strategy for the East Asian blood donors.

MATERIAL AND METHODS

RhD phenotyping, weak D testing and RhCE phenotyping were performed on 110 samples from members of the RhD-negative club, private organization composed of RhD-negative blood donors, in the GwangJu-Chonnam region of Korea. The RHD promoter, intron 4, and exons 7 and 10 were analysed by real-time PCR. Two nucleotide changes (c.1227 G>A, and c.1222 T>C) in exon 9 were analysed by sequencing.

RESULTS

Of 110 RhD-negative club members, 79 (71·8%) showed complete deletion of the RHD gene, 10 (9·1%) showed results consistent with RHD-CE-D hybrid, and 21 (19·1%) showed amplification of RHD promoter, intron 4, and exons 7 and 10. Of the latter group, 16 (14·5%) were in the DEL blood group including c.1227 G>A (N = 14) and c.1222 T>C (N = 2), 2 (1·8%) were weak D, 1(0·9%) was partial D, and 2 (1·8%) were undetermined. The RhD-negative phenotype samples consisted of 58 C-E-c+e+, 19 C-E+c+e+, 3 C-E+c+e-, 21 C+E-c+e-, 6 C+E-c+e+ and 3 C+E-c-e + . Notably, all 58 samples with the C-E-c+e+ phenotype were revealed to have complete deletion of the RHD gene. The C-E-c+e+ phenotype showed 100% positive predictive value for detecting D-negative cases.

CONCLUSIONS

RHD genotyping is not required in half of D-negative cases. We suggest here an effective RHD genotyping strategy for accurate detection of RhD variants in apparently RhD-negative blood donors in East Asia.

Natural magnetic nanoparticle containing droplet for smart drug delivery and heat treatment

Biodegradable polymer droplet containing natural magnetic nanoparticle is composed for smart drug delivery and heat treatment. For selective and efficient drug delivery to the target tissue, direct high magnetic field will be applied near the target tissue. For drug release control and heat treatment, alternative high magnetic field will be applied. Magnetosome, natural magnetic nanoparticle, is extracted from magnetotactic bacteria, AMB-1. Mixture of magnetosome and sodium alginate composes into droplet using the microfluidic device applied Plateau-Rayleigh instability principle. The magnetosome contained droplet selected its rout at the bifurcate microchannels by direct high magnetic field. High alternative magnetic field generating circuit is designed with 18 mT and 4 Hz magnetic wave. The generated magnetic wave was applied to the extracted magnetosomes so that temperature of the magnetosomes increased from 15.2°C to 17.6°C.

Displacement measurement using an optoelectronic oscillator with an intra-loop Michelson interferometer

We report on measurement of small displacements with sub-nanometer precision using an optoelectronic oscillator (OEO) with an intra-loop Michelson interferometer. In comparison with conventional homodyne and heterodyne detection methods, where displacement appears as a power change or a phase shift, respectively, in the OEO detection, the displacement produces a shift in the oscillation frequency. In comparison with typical OEO sensors, where the frequency shift is proportional to the OEO oscillation frequency in radio-frequency domain, the frequency shift in our method with an intra-loop interferometer is proportional to an optical frequency. We constructed a hybrid apparatus and compared characteristics of the OEO and heterodyne detection methods.

Protein stability changes of the novel p.Arg180Cys mutant A glycosyltransferase resulted in a weak A phenotype

A novel A subgroup allele (c.538C>T p.Arg180Cys) showing weak A phenotype was found in a 30-year-old Korean woman with ABO discrepancy. Using 3D structural analysis, protein stability prediction and flow cytometric analysis of ABO antigen expression on HeLa cells transfected with plasmids containing the p.Arg180Cys mutant, we found that the Arg180 residue in the loop region of the A glycosyltransferases (GTA) structure plays significant role in stabilizing its closed conformation, which is required for substrate binding and catalysis study.

Magic polarization for optical trapping of atoms without Stark-induced dephasing

We demonstrate that the differential ac-Stark shift of a Zeeman-sensitive ground hyperfine transition in an optical trap can be eliminated by using properly polarized trapping light. We use the vector polarizability of an alkali-metal atom to produce a polarization-dependent ac-Stark shift that resembles a Zeeman shift. We study a transition from the |2S1/2,F=2,mF=-2> to the |2S1/2,F=1,mF=-1> state of 7Li to observe 0.59±0.02  Hz linewidth with interrogation time of 2 s and 0.82±0.06  s coherence time of a superposition state. Implications of the narrow linewidth and the long coherence time for precision spectroscopy and quantum information processing using atoms in an optical lattice are discussed.

Expanded carrier screening in reproductive healthcare: perspectives from genetics professionals

STUDY QUESTION

How do genetics professionals assess the potential benefits and challenges of expanded carrier screening (ECS) in reproductive healthcare?

SUMMARY ANSWER

Genetics professionals believe that current ECS products have major limitations and are not ready for routine use in reproductive healthcare.

WHAT IS KNOWN ALREADY

Non-targeted approaches to carrier screening have been met with uneven enthusiasm from relevant professional organizations. With declining genotyping costs, it is reasonable to expect that the number of genetic conditions evaluated by carrier-screening products will continue to increase. Reproductive healthcare providers will play a critical role in the adoption of ECS and need to be prepared for the potential challenges that lie ahead.

STUDY DESIGN, SIZE, DURATION

Focus groups were convened at six academic medical centers in the USA in March 2011 to examine genetics professionals' views on ECS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Forty genetic professionals participated in six focus groups for this study. A clinical case report was presented to each focus group to examine participants' opinions about the use of highly multiplexed forms of carrier screening in reproductive healthcare. Focus group transcripts were analyzed for major themes and thematic density across sites using qualitative data analysis software (ATLAS.ti v5.8).

MAIN RESULTS AND THE ROLE OF CHANCE

Participants believed that current ECS products have major limitations pertaining to the analysis of select alleles and genetic mutations. Participants highlighted multiple interpretive and counseling challenges that reproductive healthcare providers may face in communicating ECS results to patients. Participants stressed the importance of communicating these and other limitations to patients before recommending ECS. Participants recommended collaboration with genetic counselors and medical geneticists in providing ECS.

LIMITATIONS, REASONS FOR CAUTION

To the extent that ECS products have not been widely used to date, participants may have had limited familiarity and direct clinical experience with these products. Given that this study was conducted with genetic professionals from academic medical centers in the USA, participant perspectives may not be representative of professional practices and norms in other healthcare settings.

WIDER IMPLICATIONS OF THE FINDINGS

In considering the use of ECS products in their practices, reproductive healthcare providers may find it helpful to consider the perspectives of genetics professionals. These specialists have considerable experience with diverse forms of genetic testing and can provide valuable insights regarding new genomic risk assessment tools such as ECS.

Electrical characteristics of 2D and 3D microelectrodes for high-resolution retinal prostheses

In order to provide high quality visual information to patients who have implanted retinal prosthetic devices, the number of microelectrode should be large. As the number of microelectrode is increased, the dimension of the microelectrode is decreased, which in turn results in the increased interface impedance of microelectrode and decreased dynamic range of injection current. In addition, the reduced maximum limit of injection current may not be sufficiently large to stimulate the ganglion cells in a retina. In order to improve the trade-off envelope between number of microelectrode and current injection limit, a 3D microelectrode structure can be used as an alternative. From the advancement of microfabrication technology, the fabrication of highly-accurate 3D structures with small dimensions is possible. This paper presents a first comprehensive electrical characterization of 2D and 3D microelectrodes for high-resolution retinal prostheses. Microelectrodes which differ in shapes and diameters are analyzed. Their interface impedances and charge injection limits are quantitatively analyzed. This research can be used to define requirements for further retinal prosthetic device research.

A new HLA-C*07:244 allele identified by sequence-based typing in a Korean individual

The C*07:244 changes single nucleotide of C*07:02:01 at codon 75 (CGA → CAA), Arg to Gln.

Optoelectronic oscillator stabilized to an intra-loop Fabry-Perot cavity by a dual servo system

We report construction and characterization of an optoelectronic oscillator (OEO), which is stabilized to an intra-loop Fabry-Perot cavity by a dual servo system. In addition to providing strong mode selection and increasing the Q factor by adding significant loop length, the cavity serves as a stable frequency reference. In order to fully exploit the stability we employ a dual servo system. Carrier frequency is locked to the cavity mode by using Pound-Drever-Hall technique. The OEO loop length is adjusted by comparing the phase difference between the carrier-sideband beat signals at upstream and downstream sides of the cavity so that the OEO mode spacing is commensurate with the free spectral range of the cavity. This dual servo system and additional stabilizations of the seed laser frequency to a cesium transition and the laser power result in an order of magnitude improvement in OEO frequency stability over a previous work using a free-running Fabry-Perot cavity. Long term Allan deviation of the OEO is 6 x 10(-8). It represents 4 x 10(-4)of the cavity resonance linewidth. We also discuss possibility of relating the OEO frequency to an atomic transition as an absolute frequency reference.

Production of a coherent pair of light beams with a microwave frequency difference from a single extended-cavity diode laser

We produced a pair of coherent laser beams with a 3-GHz frequency difference by optically phase locking two modes from a single, multimode extended-cavity diode laser. This method is complementary to either a direct modulation or an optical phase locking of two independent lasers. A large differential frequency shift between the two modes of the laser allows efficient phase locking. We developed a simple theory to account for the large differential frequency shift. Allan deviation of the beat frequency when the two modes are phase-locked drops as an inverse of the measurement time and it reaches 10(-14) when the time is 1 h. Coherent population trapping spectroscopy of Rb atoms using the phase-locked beams resulted in a spectrum as narrow as that of the case using direct modulation by a stable frequency synthesizer.