Long-term survival in patients with brain-only metastatic non-small cell lung cancer undergoing upfront intracranial stereotactic radiosurgery and definitive treatment to the thoracic primary site

BACKGROUND AND PURPOSE

To evaluate modern clinical outcomes for patients with brain-only metastatic non-small cell lung cancer (NSCLC) treated with intracranial stereotactic radiosurgery (SRS) with or without definitive treatment of the primary site.

MATERIALS AND METHODS

Patients with synchronously diagnosed NSCLC and brain-only metastatic disease treated with intracranial SRS at a single institution were retrospectively identified. Patients were stratified based on whether they did (A) or did not (B) receive definitive primary site treatment. Patient characteristics and clinical outcomes were compared.

RESULTS

From 2008 to 2022, 103 patients were identified, 53 of whom received definitive primary site treatment. Median follow-up was 2.1 y (A) and 0.8 y (B) (p < 0.001). 28 (53 %) patients in Group A received immune checkpoint inhibitor (ICI) therapy versus 19 (38 %) in Group B (p = 0.13) and there were no other statistically significant baseline or treatment characteristic differences between the groups. 5-year local-PFS was 34.5 % (A) versus 0 % (B) (p < 0.001). 5-year regional-PFS was 33.0 % (A) versus 0 % (B) (p < 0.001). 5-year distant body-PFS was 34.0 % (A) versus 0 % (B) (p < 0.001). 5-year CNS-PFS was 14.7 % (A) versus 0 % (B) (p = 0.12). 5-year OS was 40.2 % (A) versus 0 % (B) (p = 0.001). 5-year CSS was 67.6 % (A) versus 0 % (B) (p = 0.002). On multivariable analysis, lack of definitive treatment to the primary site (HR = 2.40), AJCC T3-4 disease (HR = 2.73), and lack of ICI therapy (HR = 2.86) were significant predictors of death.

CONCLUSION

Definitive treatment to the thoracic primary site in patients with brain-only metastatic NSCLC after intracranial radiosurgery was associated with slower progression of disease and improved survival.

Cardiac function is normal in most patients recovered from COVID-19

Background

There are conflicting results regarding impaired cardiac function in patients that have recovered from COVID-19. Cardiovascular magnetic resonance (CMR) studies have revealed a very high frequency of cardiac involvement (78%) and ongoing myocardial inflammation (60%) in patients recently recovered from COVID-19. Findings are advocating further investigation of the long-term myocardial consequences of COVID-19 disease.

Purpose

We aimed to investigate left ventricular (LV) and right ventricular (RV) function by a comprehensive echocardiographic study in patients recovered from COVID-19 infection 3 months after admission to hospital.

Methods

All patients (n=92) had been hospitalized for COVID-19 and were examined with echocardiography three months after hospitalization. They were 59±13 years, and 43% were women. LV function was assessed by ejection fraction (EF) and global longitudinal strain (GLS) and RV function was measured by fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE) and RV GLS free wall. Tricuspid regurgitation pressure gradient was measured to estimate pulmonary artery pressure.

Results

LV EF was 63±6% and LV GLS was −18.6±2.2%. All patients had normal EF &gt;53%, but 10 showed signs of subtle impaired LV function by LV GLS (≥ −16%). Only two of these did not have hypertension, LV hypertrophy, diabetes or other preexisting diagnosis of heart disease explaining subtle LV dysfunction. All had normal RV FAC (48±7%) and TAPSE (2.3±0.3 cm). We found modestly impaired RV longitudinal function (RV GLS free wall &gt;−25%) in 30% patients, but none had RV GLS worse than −20%. One-third of all patients with reduced RV GLS had signs of elevated pulmonary arterial pressures, which might impact the assessment of RV function.

Conclusions

Traditional echocardiographic parameters showed normal function in all hospitalized COVID-19 patients three months after hospital admittance. Approximately one-third had subtle ventricular dysfunction detected by sensitive echocardiographic methods, but these findings could mostly be explained by systemic or pulmonary hypertension. We cannot, however, exclude that a slight reduction in cardiac function in a minority of our patients was caused by the COVID-19 infection.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): National Clinical Therapy Research in the Specialist Health Services, Norway

Multi-chord IR-visible two-color interferometer on KSTAR

Major parts of an IR-visible two-color interferometer (TCI) on KSTAR have been upgraded for the multi-chord operation: (1) a diode-pumped-solid-state (DPSS) laser (660 nm) replacing the former HeNe laser (633 nm), (2) vacuum-compatible vibration isolator with titanium retro-reflectors, and (3) full digital phase comparator for multi-chord real-time density signals. The commercial compact DPSS laser suits the multiple chord configuration with its strong beam power (500 mW) and long coherent length (>100 m). Ti retro-reflectors are mounted on vacuum-compatible vibration isolators. The isolators are essential for the visible beams to avoid any fringe skips due to their short wavelength, considering the speed of the mechanical vibration (up to hundreds of μm). Field-programmable-gate-array (FPGA) modules count the entire fringes fast enough with a signal output rate up to 1.25 MHz, solving the fringe skip issues. The FPGA module enables the full digital processing of the phase comparator with a CORDIC algorithm after the sampling rate of 160 MS/s for the 40 MHz intermediate frequency of each beam. The full digital signals are transferred to the main plasma control system in real-time. Stable single-input-single-output operation of the KSTAR density control was demonstrated with the TCI. The real-time density profile control is also promising in the near future, with multiple actuators such as pellets and gas puffings.

The new single crystal dispersion interferometer installed on KSTAR and its first measurement

Dispersion interferometers have been used to measure line integrated electron densities from many fusion devices. To optically suppress noise due to mechanical vibrations, a conventional dispersion interferometer typically uses two nonlinear crystals located before and after the plasma along the laser beam path. Due to the long beam path, it can be difficult to overlap the fundamental and second harmonic laser beams for a heterodyne dispersion interferometer and to focus the beams on the second nonlinear crystal located after the plasma, especially when the aperture of the nonlinear crystal is small, i.e., of the order of mm. To overcome such difficulties, a new concept of a heterodyne dispersion interferometer, a single crystal dispersion interferometer (SCDI), is developed and installed on KSTAR with the laser wavelength of 1064 nm. The concept and the optical setup of the KSTAR SCDI are discussed, as well as its first measurement during a shattered pellet injection that produces abrupt and large changes in the electron density. To demonstrate feasibility, the KSTAR SCDI measurements are also compared with those from the existing two-color interferometer.

Development of a forward model for Bayesian analysis of a single crystal dispersion interferometer

The Single Crystal Dispersion Interferometer (SCDI) is a newly developed dispersion interferometer (DI) system installed on KSTAR and has obtained the first data successfully in January 2020. Unlike conventional heterodyne DI systems, which use two nonlinear crystals, only one nonlinear crystal is used to eliminate the difficulty in overlapping the first and second harmonic beams, aligning and focusing the beams to a small aperture of the second nonlinear crystal, and resolving a problem of significant efforts to maintain the beam alignment to the second nonlinear crystal after a long beam transmission. The second nonlinear crystal is replaced by a frequency doubler, a simple electronic component. To infer a line integrated electron density with its associated uncertainty consistent with the measured data, we develop a forward model of the KSTAR SCDI that can be used as a likelihood within a Bayesian-based data analysis routine. The forward model consists of two main parts, which are an optical system and an electronics system, and it takes into account noises by modeling the mechanical vibrations and the electronic noises as Gaussian distributions, while the photon noise is modeled with a Poisson distribution. The developed forward model can be used for designing and improving the SCDI system.

Prognostic factors analysis for oral cavity cancer survival in the Netherlands and Taiwan using a privacy-preserving federated infrastructure

The difference in incidence of oral cavity cancer (OCC) between Taiwan and the Netherlands is striking. Different risk factors and treatment expertise may result in survival differences between the two countries. However due to regulatory restrictions, patient-level analyses of combined data from the Netherlands and Taiwan are infeasible. We implemented a software infrastructure for federated analyses on data from multiple organisations. We included 41,633‬ patients with single-tumour OCC between 2004 and 2016, undergoing surgery, from the Taiwan Cancer Registry and Netherlands Cancer Registry. Federated Cox Proportional Hazard was used to analyse associations between patient and tumour characteristics, country, treatment and hospital volume with survival. Five factors showed differential effects on survival of OCC patients in the Netherlands and Taiwan: age at diagnosis, stage, grade, treatment and hospital volume. The risk of death for OCC patients younger than 60 years, with advanced stage, higher grade or receiving adjuvant therapy after surgery was lower in the Netherlands than in Taiwan; but patients older than 70 years, with early stage, lower grade and receiving surgery alone in the Netherlands were at higher risk of death than those in Taiwan. The mortality risk of OCC in Taiwanese patients treated in hospitals with higher hospital volume (≥ 50 surgeries per year) was lower than in Dutch patients. We conducted analyses without exchanging patient-level information, overcoming barriers for sharing privacy sensitive information. The outcomes of patients treated in the Netherlands and Taiwan were slightly different after controlling for other prognostic factors.

The Role of Postoperative Radiation Therapy for pN2 Non-small-cell Lung Cancer

BACKGROUND

The role for postoperative radiation therapy (PORT) for patients with non-small-cell lung cancer (NSCLC) with mediastinal lymph node (LN) involvement (pN2 disease) is controversial. We compared surgery alone with PORT among patients with pN2 NSCLC. We then performed subset analyses to better delineate patients that might benefit from PORT.

PATIENTS AND METHODS

We conducted a propensity score (PS)-matched, inverse probability of treatment weighting (IPTW) Surveillance, Epidemiology, and End Results (SEER) analysis of patients with pN2 disease from 1989 to 2016 with surgery alone or PORT. Multiple imputation with chained equations was used for missing LN data.

RESULTS

A total of 8631 patients were included in this analysis; 4579 underwent surgery alone, and 4052 underwent PORT. Following PS matching and IPTW, there was no difference in overall survival (OS) (hazard ratio [HR], 0.99; P = .76). However, PORT improved OS among a subset of patients with a LN positive to sampled ratio ≥ 50% (HR, 0.90; P = .01). Moreover, there was a trend towards improved OS among this subset, even with chemotherapy (HR, 0.91; P = .09).

CONCLUSION

PORT is not associated with an improvement or detriment in OS for all patients with pN2 NSCLC. However, patients with a positive to sampled LN ratio ≥ 50% may benefit, regardless of chemotherapy status. Nevertheless, PORT will remain the standard of care as we await the results of the ongoing LUNG ART trial.

Repeat Stereotactic Radiosurgery for Progressive or Recurrent Vestibular Schwannomas

BACKGROUND

Stereotactic radiosurgery (SRS) is a highly effective management approach for patients with vestibular schwannomas (VS), with 10-yr control rates up 98%. When it fails, however, few data are available to guide management.

OBJECTIVE

To perform a retrospective analysis of patients who underwent 2 SRS procedures on the same VS to assess the safety and efficacy of this practice.

METHODS

This study was opened to centers of the International Gamma Knife Research Foundation (IGKRF). Data collected included patient characteristics, clinical symptoms at the time of SRS, radiosurgery dosimetric data, imaging response, clinical evolution, and survival. Actuarial analyses of tumor responses were performed.

RESULTS

Seventy-six patients from 8 IGKRF centers were identified. Median follow-up from the second SRS was 51.7 mo. Progression after the first SRS occurred at a median of 43 mo. Repeat SRS was performed using a median dose of 12 Gy. Actuarial tumor control rates at 2, 5, and 10 yr following the second SRS were 98.6%, 92.2%, and 92.2%, respectively. Useful hearing was present in 30%, 8%, and 5% of patients at first SRS, second SRS, and last follow-up, respectively. Seventy-five percent of patients reported stable or improved symptoms following the second SRS. Worsening of facial nerve function attributable to SRS occurred in 7% of cases. There were no reports of radionecrosis, radiation-associated edema requiring corticosteroids, radiation-related neoplasia, or death attributable to the repeat SRS procedure.

CONCLUSION

Patients with progressing VS after radiosurgery can be safely and effectively managed using a second SRS procedure.

Investigating the intra- and inter-rater reliability of a panel of subjective and objective burn scar measurement tools

•

Subjective scar measures have poor reliability unless repeated by more than one assessor.

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Objective scar measures have been demonstrated to have good to excellent reliability.

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Physical symptoms of scars such as pain and itch were found to be more important to patients compared to surface, area and colour although this finding was not sustained when corrected for multiple comparisons.

Background

Research into the treatment of hypertrophic burn scar is hampered by the variability and subjectivity of existing outcome measures. This study aims to measure the inter- and intra-rater reliability of a panel of subjective and objective burn scar measurement tools.

Methods

Three independent assessors evaluated 55 scar and normal skin sites using subjective (modified Vancouver Scar Scale [mVSS] & Patient and Observer Scar Assessment Scale [POSAS]) and objective tools. The intra-class correlation coefficient was utilised to measure reliability (acceptable when >0.70). Patient satisfaction with the different tools and scar parameter importance were assessed via questionnaires.

Results

The inter-rater reliabilities of the mVSS and POSAS were below the acceptable limit. For erythema and pigmentation, all of the Scanoskin and DSM II measures (except the b* value) had acceptable to excellent intra and inter-rater reliability. The Dermascan ultrasound (dermal thickness, intensity) had excellent intra- and inter-rater reliability (>0.90). The Cutometer R0 (firmness) had acceptable reliability but not R2 (gross elasticity). All objective measurement tools had good overall satisfaction scores. Patients rated scar related pain and itch as more important compared to appearance although this finding was not sustained when corrected for multiple comparisons.

Conclusion

The objective scar measures demonstrated acceptable to excellent intra- and inter-rater reliability and performed better than the subjective scar scales.

Abstract OT2-04-02: A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress

Background

In patients with early stage breast cancer, regional nodal irradiation (RNI) is added to whole breast irradiation (WBI) in order to control microscopic regional disease and to prevent systemic spread of cancer. According to recent randomized trials (MA.20 and EORTC 22922-10925), prophylactic RNI was associated with improvement in disease-free survival (DFS) in the patients with high-risk node negative or pN1 breast cancer. However, systemic agents now known to improve loco-regional control, such as taxane or endocrine therapy, were prescribed to a small percentage of patients in the studies. The benefit of RNI found in the previous studies might be attributed to incorporation of less effective systemic treatments. The impact of prophylactic RNI in pN1 breast cancer should be evaluated in the patients receiving modern systemic treatment. The current study was conducted to compare the effect of post-lumpectomy WBI vs WBI plus RNI on DFS in pN1 breast cancer patients who received adjuvant taxane-based chemotherapy.

Methods

This study is a multicenter, phase 3, randomized controlled non-inferiority trial (NCT03269981). Eligibility criteria are ≥ 20 years female; pathologically proven invasive carcinoma of the breast; one to three positive axillary lymph nodes (pN1) in pathologic specimen; receiving breast-conserving surgery followed by taxane-based chemotherapy; having adjuvant endocrine therapy or anti-HER2 treatment according to molecular subtype of tumor. Patients are randomly assigned in a 1:1 ratio to receive WBI or WBI plus RNI. Patient randomization was stratified by molecular subtype of tumor (i.e. luminal A/luminal B/luminal HER2/HER2-enriched/triple-negative) and methods of axillary management (i.e. sentinel lymph node biopsy/axillary lymph node dissection). The primary outcome is DFS. The secondary outcomes include DFS according to molecular subtype, treatment-related toxicity, and patient's quality of life per EORTC QLQ-C30 and QLQ-BR23. Patients will be followed for survival and disease recurrence for seven years. A total of 1,926 patients are planned to be enrolled, with recruitment initiated in April 2017. As of June 2018, a total of 236 patients were enrolled.

Acknowledgement

This study was supported by a grant from the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (grant number: HA17C0043010018).

Citation Format: Kim H, Park W, Choi DH, Ahn SJ, Kim SS, Kim ES, Lee JH, Lee KC, Kim JH, Lee H-S, Kim JH, Kim MY, Park HJ, Kim K, Song SH, Kwon J, Lee IJ, Kim TH, Kim TG, Chang AR, Cho O, Jeong BK, Ha B, Lee J, Ki Y. A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress [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 OT2-04-02.

Sudden arrhythmia death syndrome in young victims: a five-year retrospective review and two-year prospective molecular autopsy study by next-generation sequencing and clinical evaluation of their first-degree relatives

OBJECTIVE

Sudden arrhythmia death syndrome (SADS) accounts for about 30% of causes of sudden cardiac death (SCD) in young people. In Hong Kong, there are scarce data on SADS and a lack of experience in molecular autopsy. We aimed to investigate the value of molecular autopsy techniques for detecting SADS in an East Asian population.

METHODS

This was a two-part study. First, we conducted a retrospective 5-year review of autopsies performed in public mortuaries on young SCD victims. Second, we conducted a prospective 2-year study combining conventional autopsy investigations, molecular autopsy, and cardiac evaluation of the first-degree relatives of SCD victims. A panel of 35 genes implicated in SADS was analysed by next-generation sequencing.

RESULTS

There were 289 SCD victims included in the 5-year review. Coronary artery disease was the major cause of death (35%); 40% were structural heart diseases and 25% were unexplained. These unexplained cases could include SADS-related conditions. In the 2-year prospective study, 21 SCD victims were examined: 10% had arrhythmogenic right ventricular cardiomyopathy, 5% had hypertrophic cardiomyopathy, and 85% had negative autopsy. Genetic analysis showed 29% with positive heterozygous genetic variants; six variants were novel. One third of victims had history of syncope, and 14% had family history of SCD. More than half of the 11 first-degree relatives who underwent genetic testing carried related genetic variants, and 10% had SADS-related clinical features.

CONCLUSION

This pilot feasibility study shows the value of incorporating cardiac evaluation of surviving relatives and next-generation sequencing molecular autopsy into conventional forensic investigations in diagnosing young SCD victims in East Asian populations. The interpretation of genetic variants in the context of SCD is complicated and we recommend its analysis and reporting by qualified pathologists.

Use of Intrathecal Neostigmine as an Adjunct to Other Spinal Medications in Perioperative and Peripartum Analgesia: A Meta-analysis

Intrathecal neostigmine has been used as an adjunct to intrathecal local anaesthetic or opioid to prolong regional analgesia and improve haemodynamic stability, with variable results. This meta-analysis aims to evaluate the effectiveness and side-effects of intrathecal neostigmine in the perioperative and peripartum settings. The literature search was based on Cochrane Controlled Trials Register, EMBASE and MEDLINE (from 1966 to 14 November 2003) databases. Volunteer and animal studies were excluded. We identified 26 studies and 19 were considered suitable for detailed data extraction. Intrathecal neostigmine increased the incidence of nausea and vomiting (OR 5.0, 95% CI: 3.4 to 7.3; P<0.00001), bradycardia requiring intravenous atropine (OR 2.7, 95% CI: 1.4 to 5.4; P=0.005), and anxiety, agitation, or restlessness (OR 10.3, 95% CI: 3.7 to 28.9; P=0.00001). It improved the overall 24 hour VAS score (–1.4 VAS pain score, 95% CI: -1.7 to -1.2, P<0.00001), delayed the time of first request for rescue analgesia (168 min, 95% CI: 125 to 211; P<0.00001), and reduced the total number of rescue injections of nonsteroidal anti-inflammatory drug within the first 24 hours (-0.8, 95% CI: -1.1 to -0.4; P=0.00001). It did not affect the duration of motor blockade (3.5 min, 95% CI: -1.5 to 8.6; P=0.17) or the total amount of ephedrine required (-0.4 mg, 95% CI: -1.5 to 0.7; P=0.5). Adding intrathecal neostigmine to other spinal medications improves perioperative and peripartum analgesia marginally when compared with placebo. It is associated with significant side-effects and the disadvantages outweigh the minor improvement in analgesia achieved.

Hypopituitarism after Gamma Knife radiosurgery for pituitary adenomas: a multicenter, international study

OBJECTIVE

Recurrent or residual adenomas are frequently treated with Gamma Knife radiosurgery (GKRS). The most common complication after GKRS for pituitary adenomas is hypopituitarism. In the current study, the authors detail the timing and types of hypopituitarism in a multicenter, international cohort of pituitary adenoma patients treated with GKRS.

METHODS

Seventeen institutions pooled clinical data obtained from pituitary adenoma patients who were treated with GKRS from 1988 to 2016. Patients who had undergone prior radiotherapy were excluded. A total of 1023 patients met the study inclusion criteria. The treated lesions included 410 nonfunctioning pituitary adenomas (NFPAs), 262 cases of Cushing's disease (CD), and 251 cases of acromegaly. The median follow-up was 51 months (range 6-246 months). Statistical analysis was performed using a Cox proportional hazards model to evaluate factors associated with the development of new-onset hypopituitarism.

RESULTS

At last follow-up, 248 patients had developed new pituitary hormone deficiency (86 with NFPA, 66 with CD, and 96 with acromegaly). Among these patients, 150 (60.5%) had single and 98 (39.5%) had multiple hormone deficiencies. New hormonal changes included 82 cortisol (21.6%), 135 thyrotropin (35.6%), 92 gonadotropin (24.3%), 59 growth hormone (15.6%), and 11 vasopressin (2.9%) deficiencies. The actuarial 1-year, 3-year, 5-year, 7-year, and 10-year rates of hypopituitarism were 7.8%, 16.2%, 22.4%, 27.5%, and 31.3%, respectively. The median time to hypopituitarism onset was 39 months.In univariate analyses, an increased rate of new-onset hypopituitarism was significantly associated with a lower isodose line (p = 0.006, HR = 8.695), whole sellar targeting (p = 0.033, HR = 1.452), and treatment of a functional pituitary adenoma as compared with an NFPA (p = 0.008, HR = 1.510). In multivariate analyses, only a lower isodose line was found to be an independent predictor of new-onset hypopituitarism (p = 0.001, HR = 1.38).

CONCLUSIONS

Hypopituitarism remains the most common unintended effect of GKRS for a pituitary adenoma. Treating the target volume at an isodose line of 50% or greater and avoiding whole-sellar radiosurgery, unless necessary, will likely mitigate the risk of post-GKRS hypopituitarism. Follow-up of these patients is required to detect and treat latent endocrinopathies.

Fringe jump compensation techniques for the time-averaging zero-crossing phase measurement in the KSTAR millimeter-wave interferometer

A fringe jump compensation algorithm has been developed for a phase measurement that measures the phase within a single fringe. The algorithm is extremely useful in the case of the time-averaging zero-crossing phase detector on noisy environments. When the noise level on the measurements is not sufficiently suppressed, the signals near the fringe jump show a negative slope instead of a sharp drop. The slope brings an ambiguity over the compensation process. An algorithm with an additional channel that measures the phase of a half fringe shift has been applied in the millimeter-wave interferometer on the Korea Superconducting Tokamak Advanced Research device. These techniques removed the ambiguity in most cases. The algorithm can provide a most simple, robust, and cost-effective solution for the phase measurement system in various fields.

Double-blind placebo-controlled multicenter phase II trial to evaluate D-methionine in preventing/reducing oral mucositis induced by radiation and chemotherapy for head and neck cancer

BACKGROUND

The purpose of this study was to test if oral D-methionine (D-met) reduced mucositis during chemoradiotherapy.

METHODS

We conducted a placebo-controlled double-blind randomized phase II trial of D-met (100 mg/kg p.o. b.i.d.) testing the rate of severe (grades 3-4) mucositis.

RESULTS

Sixty patients were randomized. Grade 2 + oral pain was higher with placebo (79% vs 45%; P = .0165), whereas grade 2 + body odor was greater with D-met (3% vs 41%; P = .0015). Mucositis was decreased with D-met by the physician (World Health Organization [WHO], P = .007; Radiation Therapy Oncology Group [RTOG], P = .009) and patient functional scales (RTOG, P = .0023). The primary end point of grades 3 to 4 mucositis on the composite scale demonstrated a decrease with D-met (48% vs 24%; P = .058), which was borderline in significance. A planned secondary analysis of a semiquantitative scoring system noted decreased oral ulceration (2.2 vs 1.5; P = .023) and erythema (1.6 vs 1.1; P = .048) with D-met.

CONCLUSION

Although not meeting the primary end point, results of multiple assessments suggest that D-met decreased mucositis.

The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong

INTRODUCTION

Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM.

METHODS

The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling.

RESULTS

In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years.

CONCLUSION

The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Operation results of the KSTAR far infrared interferometer

The 2015 KSTAR experimental campaign was the first year of routine measurement with a far infrared interferometer (FIRI) utilizing 118.87 μm CH₃OH lasers at maximum 200 mW CW beam power. By using rtEFIT reconstruction, the path lengths of interferometers can be calculated and so the line-averaged electron densities n¯_e from the FIRI and a millimeter-wave interferometer were in excellent agreement. In this way, the number of successfully diagnosed discharges is counted: 1003 shots or 83.7% of sustained discharges, defined as shots of plasma current I_P ≥ 0.3 MA with pulse lengths t_f ≥ 2.0 s, have good-quality FIRI data within a few fringe jump errors. In addition, real-time H-mode density feedback control based on the FIRI was also successfully achieved with supersonic molecular beam injection as an actuator. Both constant density and controlled linear increment with a ramp-up rate of 1.0 × 10¹⁹ m^-3 s^-1 were achieved.

Neonatal mortality and topical application of chlorhexidine on umbilical cord stump: a meta-analysis of randomized control trials

OBJECTIVE

To examine the efficacy of topical chlorhexidine as an intervention on neonatal umbilical cord stumps and its association with neonatal mortality and omphalitis.

STUDY DESIGN

Meta-analysis of randomized controlled trials (RCTs).

METHOD

PubMed, EMBASE, CINAHL, IMSEAR, Google Scholar, Cochrane Central Register of Controlled Trials, Cochrane Pregnancy and Childbirth Group's Trials Register and Clinicaltrials.gov were screened until September 1, 2015 to identify RCTs that met the inclusion criteria. Pooled relative risks (RR) with 95% confidence intervals (CI) were calculated.

RESULTS

Five RCTs, conducted in Italy, Bangladesh, Nepal, Pakistan and India with a total of 55,008 participants were identified. Analysis revealed a significant reduction in the incidence of neonatal mortality among the intervention group as compared to the control group (pooled RR = 0.8; 95% CI: 0.6-1.0; P = 0.04; random effects model, I² = 58%; χ² = 9.5; P = 0.05). Additionally, decreased incidence in omphalitis was seen in the intervention group as compared to the control group (pooled RR = 0.4; 95% CI: 0.3-0.7; P < 0.001; random effects model, I² = 50%; χ² = 8.0; P = 0.09).

CONCLUSIONS

Application of chlorhexidine to newborn umbilical cord stumps, significantly reduce the incidences of both neonatal mortality and omphalitis. However, high-quality trials from different regions and obstetric settings may help form more conclusive judgement on universal application of topical chlorhexidine.

Cardiac transplantation and concomitant coronary artery bypass grafting: our experiences in 11 cases

INTRODUCTION

The shortage of donor hearts for transplantation could be alleviated by including the hearts of older donors. Previous literature revealed similar early and medium-term survival outcomes compared with those of younger donors. This study presents our experience with patients who underwent orthotopic heart transplantation and concomitant coronary artery bypass grafting at our institution.

METHODS

We present our experience with 11 patients with end-stage cardiomyopathy (8 men and 3 women) undergoing orthotopic heart transplantation and concomitant coronary artery bypass grafting from September 2002 to November 2011 at our institute.

RESULTS

All 11 donor organs would otherwise have been rejected, depriving potential recipients of organ transplantation. Two patients received concurrent 2-coronary-artery bypass, and the other 9 patients received concurrent single-coronary-artery bypass during orthotopic heart transplantation. All patients had an uneventful postoperative course, with follow-up completed 3 to 128 months after cardiac transplantation and concomitant coronary artery bypass grafting surgery.

CONCLUSIONS

Our experiences suggest that donor hearts requiring coronary artery bypass grafting, which form a small but significant donor subgroup, can be used effectively and safely when matched to the recipients' age and medical condition.

Prevalence, outcome and risk factors for postoperative pyothorax in 232 dogs undergoing thoracic surgery

Objective

To determine the prevalence, outcome and risk factors for postoperative pyothorax in dogs undergoing thoracic surgery.

Methods

Case records were reviewed retrospectively to identify dogs with post thoracic surgery pyothorax, defined as septic neutrophilic inflammation within the pleural space based on cytology and/or a positive bacterial culture of pleural fluid. Those identified were reviewed for potential risk factors for postoperative pyothorax based on biological plausibility and previously published data. These potential risk factors were explored by multivariable logistic regression.

Results

Of 232 dogs undergoing thoracic surgery, 15 (6·5%) dogs developed pyothorax. Bacteria cultured included methicillin-resistant Staphylococcus aureus and multi-resistant Escherichia coli. Of these dogs, six died, four were euthanased and five were treated successfully. A diagnosis of idiopathic chylothorax [Odds Ratio (OR)=12·5, 95% Confidence Interval (CI)=2·7-58·5, P=0·001], preoperative intrathoracic biopsy (OR=14·3, 95% CI=1·7-118·7, P=0·014) and preoperative thoracocentesis (OR=11·2, 95% CI=1·6-78·2, P=0·015) were identified as independent risk factors for development of postoperative pyothorax.

Clinical Significance

Idiopathic chylothorax, intrathoracic biopsy and prior thoracocentesis are independent risk factors for postoperative pyothorax, which was associated with a 67% mortality rate.

Target-controlled infusion of remifentanil for laryngeal mask airway insertion during sevoflurane induction in adults

OBJECTIVE

This randomized, double-blind study investigated the suitable target effect-site concentration of remifentanil for laryngeal mask airway (LMA) insertion during inhalation induction with sevoflurane.

METHODS

Patients aged 18 - 60 years were randomly assigned to one of three groups receiving infusions of normal saline (control group), or infusions with target effect-site remifentanil concentrations of either 1 ng/ml (R1 group) or 2 ng/ml (R2 group), 1 min after the induction of anaesthesia with sevoflurane. LMA insertion was attempted 2 min after induction. Insertion conditions were graded using a six-variable, three-point scale (excellent, intermediate or poor).

RESULTS

A total of 102 patients were included. The proportion of patients ranked as excellent for the LMA insertion was significantly higher in groups R1 and R2 compared with the control group. The incidence of apnoea was significantly more frequent in the R2 group than in the control or R1 groups.

CONCLUSIONS

Compared with 1 ng/ml remifentanil or normal saline, target-controlled infusion of 2 ng/ml remifentanil significantly improved the LMA insertion conditions during sevoflurane inhalational induction, although apnoeic episodes were more frequently observed.

Multipulse addressing of a Raman quantum memory: configurable beam splitting and efficient readout

Quantum memories are vital to the scalability of photonic quantum information processing (PQIP), since the storage of photons enables repeat-until-success strategies. On the other hand, the key element of all PQIP architectures is the beam splitter, which allows us to coherently couple optical modes. Here, we show how to combine these crucial functionalities by addressing a Raman quantum memory with multiple control pulses. The result is a coherent optical storage device with an extremely large time bandwidth product, that functions as an array of dynamically configurable beam splitters, and that can be read out with arbitrarily high efficiency. Networks of such devices would allow fully scalable PQIP, with applications in quantum computation, long distance quantum communications and quantum metrology.

Single-photon-level quantum memory at room temperature

Room-temperature, easy-to-operate quantum memories are essential building blocks for future long distance quantum information networks operating on an intercontinental scale, because devices like quantum repeaters, based on quantum memories, will have to be deployed in potentially remote, inaccessible locations. Here we demonstrate controllable, broadband and efficient storage and retrieval of weak coherent light pulses at the single-photon level in warm atomic cesium vapor using the robust far off-resonant Raman memory scheme. We show that the unconditional noise floor of this technically simple quantum memory is low enough to operate in the quantum regime, even in a room-temperature environment.

Density gradient stabilization of electron temperature gradient driven turbulence in a spherical tokamak

In this Letter we report the first clear experimental observation of density gradient stabilization of electron temperature gradient driven turbulence in a fusion plasma. It is observed that longer wavelength modes, k(⊥)ρ(s) ≲ 10, are most stabilized by density gradient, and the stabilization is accompanied by about a factor of 2 decrease in the plasma effective thermal diffusivity.

BAG3-related myofibrillar myopathy in a Chinese family

In contrast to the usual slow disease progression in myofibrillar myopathies, patients with Bag3opathy often have a rapidly progressive and more severe phenotype with a worse prognosis. We describe a Chinese patient, born to non-consanguineous parents, who first presented at age 6 with clumsy walking and difficult climbing staircase. With a history of restrictive lung disease previously diagnosed as asthma, she progressed rapidly with proximal myopathy, rigid spine and bilateral tightening of the Achilles tendons requiring surgical elongation. Hypertrophic cardiomyopathy with restrictive physiology was shown by echocardiogram. Moreover, prolonged QT interval was also noted in the patient. Family history was unremarkable yet her father was incidentally found to have prolonged QT interval. Mutation analysis with genomic DNA of the proband showed heterozygous de novo known mutation c.626C>T (p.Pro209Leu) and a germline variation c.772C>T (p.Arg258Trp) in BAG3. Her father was found to be a carrier of c.772C>T. Muscle biopsy findings were suggestive of myofibrillar myopathy on light microscopy and ultrastructural studies. To our knowledge, this is the first Chinese case of Bag3opathy so far reported.

NSTX far infrared tangential interferometer/polarimeter electronics upgrade

New electronics for the multichannel far infrared tangential interferometer/polarimeter system employed on the National Spherical Torus Experiment (NSTX) have greatly extended its capability to monitor high frequency density fluctuations. Such measurements are essential in understanding transport physics issues in NSTX as well as for the coming ITER device. The electronics, which were previously limited to ∼250 kHz, have been upgraded with a video bandwidth that extends to 4 MHz when operating as an interferometry-only configuration, and to ∼500 kHz when operating as a simultaneous interferometer/polarimeter system. Experimental details and test results of the new electronics are presented.

Use of the Far Infrared Tangential Interferometer/Polarimeter diagnostic for the study of rf driven plasma waves on NSTX

A rf detection system for waves in the 30 MHz range has been constructed for the Far Infrared Tangential Interferometer/Polarimeter on National Spherical Torus Experiment (NSTX). It is aimed at monitoring high frequency density fluctuations driven by 30 MHz high harmonic fast wave fields. The levels of density fluctuations at various radial chords and antenna phase angles can be estimated using the electric field calculated by TORIC code and linearized continuity equation for the electron density. In this paper, the experimental arrangement for the detection of rf signal and preliminary results of simulation will be discussed.

Fringe-jump corrected far infrared tangential interferometer/polarimeter for a real-time density feedback control system of NSTX plasmas

The far infrared tangential interferometer/polarimeter (FIReTIP) of the National Spherical Torus Experiment (NSTX) has been set up to provide reliable electron density signals for a real-time density feedback control system. This work consists of two main parts: suppression of the fringe jumps that have been prohibiting the plasma density from use in the direct feedback to actuators and the conceptual design of a density feedback control system including the FIReTIP, control hardware, and software that takes advantage of the NSTX plasma control system (PCS). By investigating numerous shot data after July 2009 when the new electronics were installed, fringe jumps in the FIReTIP are well characterized, and consequently the suppressing algorithms are working properly as shown in comparisons with the Thomson scattering diagnostic. This approach is also applicable to signals taken at a 5 kHz sampling rate, which is a fundamental constraint imposed by the digitizers providing inputs to the PCS. The fringe jump correction algorithm, as well as safety and feedback modules, will be included as submodules either in the gas injection system category or a new category of density in the PCS.

Triggered confinement enhancement and pedestal expansion in high-confinement-mode discharges in the national spherical torus experiment

We report observation of a new high performance regime in discharges in the National Spherical Torus Experiment, where the H mode edge "pedestal" temperature doubles and the energy confinement increases by 50%. The spontaneous transition is triggered by a large edge-localized mode, either natural or externally triggered by 3D fields. The transport barrier grows inward from the edge, with a doubling of both the pedestal pressure width and the spatial extent of steep radial electric field shear. The dynamics suggest that 3D fields could be applied to reduce edge transport in fusion devices.

A transgenic mouse for imaging caspase-dependent apoptosis within the skin

Apoptosis is an essential process for the maintenance of normal physiology. The ability to noninvasively image apoptosis in living animals would provide unique insights into its role in normal and disease processes. Herein, a recombinant reporter consisting of beta-galactosidase gene flanked by two estrogen receptor regulatory domains and intervening Asp-Glu-Val-Glu sequences was constructed to serve as a tool for in vivo assessment of apoptotic activity. The results demonstrate that when expressed in its intact form, the hybrid reporter had undetectable beta-galactosidase activity. Caspase 3 activation in response to an apoptotic stimulus resulted in cleavage of the reporter, and thereby reconstitution of beta-galactosidase activity. Enzymatic activation of the reporter during an apoptotic event enabled noninvasive measurement of beta-galactosidase activity in living cells, which correlated with traditional measures of apoptosis in a dose- and time-dependent manner. Using a near-infrared fluorescent substrate of beta-galactosidase (9H-{1,3-dichloro-9,9-dimethylacridin-2-one-7-yl} beta-D-galactopyranoside), noninvasive in vivo imaging of apoptosis was achieved in a xenograft tumor model in response to proapoptotic therapy. Finally, a transgenic mouse model was developed expressing the ER-LACZ-ER reporter within the skin. This reporter and transgenic mouse could serve as a unique tool for the study of apoptosis in living cells and animals, especially in the context of skin biology.

Abstract 4199: A transgenic mouse for imaging caspase-dependent apoptosis within the skin

Apoptosis is an essential process for the maintenance of normal physiology. The ability to non-invasively image apoptosis in living animals would provide unique insights into its role in normal and disease processes. Herein, a recombinant reporter consisting of LacZ gene flanked by two ER regulatory domains and intervening DEVD sequences was constructed to serve as a tool for invivo assessment of apoptotic activity. The results demonstrate that when expressed in its intact form, the hybrid reporter had undetectable β-galactosidase activity. Caspase-3 activation in response to an apoptotic stimulus resulted in cleavage of the reporter, and thereby reconstitution of β-galactosidase activity. Enzymatic activation of the reporter during an apoptotic event enabled non-invasive measurement of β-galactosidase activity in living cells, which correlated with traditional measures of apoptosis in a dose and time dependent manner. Furthermore, using a near-infrared fluorescent substrate of β-galactosidase (DDAOG), non-invasive in vivo imaging of apoptosis was achieved using a xenograft tumor model in response to pro-apoptotic therapy. Lastly, a transgenic mouse model was developed expressing the ER-LacZ-ER reporter within the skin. This reporter and transgenic mouse could serve as a unique tool for the study of apoptosis in living cells and animals especially in context of skin biology.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4199.

Evaluation of treatment-associated inflammatory response on diffusion-weighted magnetic resonance imaging and 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography imaging biomarkers

PURPOSE

Functional imaging biomarkers of cancer treatment response offer the potential for early determination of outcome through the assessment of biochemical, physiologic, and microenvironmental readouts. Cell death may result in an immunologic response, thus complicating the interpretation of biomarker readouts. This study evaluated the temporal effect of treatment-associated inflammatory activity on diffusion magnetic resonance imaging and 2-[(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography imaging (FDG-PET) biomarkers to delineate the effects of the inflammatory response on imaging readouts.

EXPERIMENTAL DESIGN

Rats with intracerebral 9L gliosarcomas were separated into four groups consisting of control, an immunosuppressive agent dexamethasone (Dex), 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), and BCNU+Dex. Animals were imaged using diffusion-weighted magnetic resonance imaging and FDG-PET at 0, 3, and 7 days posttreatment.

RESULTS

In the BCNU- and BCNU+Dex-treated animal groups, diffusion values increased progressively over the 7-day study period to approximately 23% over baseline. The FDG percentage change of standard uptake value decreased at day 3 (-30.9%) but increased over baseline levels at day 7 (+20.1%). FDG-PET of BCNU+Dex-treated animals were found to have percentage of standard uptake value reductions of -31.4% and -24.7% at days 3 and 7, respectively, following treatment. Activated macrophages were observed on day 7 in the BCNU treatment group with much fewer found in the BCNU+Dex group.

CONCLUSIONS

Results revealed that treatment-associated inflammatory response following tumor therapy resulted in the accentuation of tumor diffusion response along with a corresponding increase in tumor FDG uptake due to the presence of glucose-consuming activated macrophages. The dynamics and magnitude of potential inflammatory response should be considered when interpreting imaging biomarker results.

Strong purified protein derivative responses are associated with poor mycobacterium inhibition in latent TB

The tuberculin skin test (TST) using purified protein derivative (PPD) of Mycobacterium tuberculosis is traditionally used to diagnose latent tuberculosis (TB) infection (LTBI). However, LTBI diagnosis by peripheral blood mononuclear cell (PBMC) interferon (IFN)-gamma responses to M. tuberculosis-specific antigens, early secreted antigenic target 6 kDa (ESAT-6) and culture filtrate protein (CFP)-10 has greater specificity. We investigated the difference in antimycobacterium cellular immunity in TB contacts who were strong TST reactors but nonresponsive to the ESAT-6/CFP-10 assay compared with those with concordant results. Healthy TB contacts were tested using the above two assays and mycobacterium survival was measured after co-culture of infected macrophages with their PBMCs. Whether PPD reactivity was tested by TST or by PBMC-specific IFN-gamma responses, strongly PPD-reactive TB contacts without ESAT-6/CFP-10 responsiveness showed significantly better mycobacterium inhibition activity than ESAT-6/CFP-10-responsive TB contacts with the same PPD reactivity. In the former group, stronger PPD reactivity was associated with improved mycobacterium killing, whereas ESAT-6/CFP-10 responders showed the opposite result. PPD-reactive ESAT-6/CFP-10-nonresponsive TB contacts in our population may have had protective immunity related to prior mycobacterium exposure. ESAT-6/CFP10-responsive TB contacts are more likely to have LTBI and, in this group, strong PPD reactivity may paradoxically be associated with poor mycobactericidal activity.

Synergy between anti-CCL2 and docetaxel as determined by DW-MRI in a metastatic bone cancer model

Metastatic prostate cancer continues to be the second leading cause of cancer death in American men with an estimated 28,660 deaths in 2008. Recently, monocyte chemoattractant protein-1 (MCP-1, CCL2) has been identified as an important factor in the regulation of prostate metastasis. CCL2, shown to attract macrophages to the tumor site, has a direct promotional effect on tumor cell proliferation, migration, and survival. Previous studies have shown that anti-CCL2 antibodies given in combination with docetaxel were able to induce tumor regression in a pre-clinical prostate cancer model. A limitation for evaluating new treatments for metastatic prostate cancer to bone is the inability of imaging to objectively assess response to treatment. Diffusion-weighted MRI (DW-MRI) assesses response to anticancer therapies by quantifying the random (i.e., Brownian) motion of water molecules within the tumor mass, thus identifying cells undergoing apoptosis. We sought to measure the treatment response of prostate cancer in an osseous site to docetaxel, an anti-CCL2 agent, and combination treatments using DW-MRI. Measurements of tumor apparent diffusion coefficient (ADC) values were accomplished over time during a 14-day treatment period and compared to response as measured by bioluminescence imaging and survival studies. The diffusion data provided early predictive evidence of the most effective therapy, with survival data results correlating with the DW-MRI findings. DW-MRI is under active investigation in the pre-clinical and clinical settings to provide a sensitive and quantifiable means for early assessment of cancer treatment outcome.

A rare cause of nephrotic syndrome: lipoprotein glomerulopathy

Lipoprotein glomerulopathy is a rare kidney disease in which lipoprotein thrombi are seen in the glomerular capillaries. Most of these patients are found in Japan and East Asian countries. The presenting symptoms include proteinuria, an abnormal plasma lipoprotein profile that resembles type III hyperlipoproteinaemia, and a marked increase in serum apolipoprotein E concentration. Previous studies have suggested that lipoprotein glomerulopathy might be related to APOE gene mutation. No effective therapeutic regimen has been established for lipoprotein glomerulopathy. We report the first case of biopsy-proven lipoprotein glomerulopathy in Hong Kong in a patient who presented with nephrotic syndrome and dyslipidaemia. DNA analysis revealed apolipoprotein E Kyoto together with a novel apolipoprotein E mutation, apolipoprotein E (Asp230Tyr) Hong Kong. There was significant improvement in the clinical parameters and resolution of symptoms after the introduction of statins. Further studies will be needed to clarify the role of apolipoprotein E Hong Kong and its interaction with apolipoprotein E Kyoto in the pathogenesis of lipoprotein glomerulopathy.

Multimode memories in atomic ensembles

The ability to store multiple optical modes in a quantum memory allows for increased efficiency of quantum communication and computation. Here we compute the multimode capacity of a variety of quantum memory protocols based on light storage in ensembles of atoms. We find that adding a controlled inhomogeneous broadening improves this capacity significantly.

Diffusion magnetic resonance imaging: an imaging treatment response biomarker to chemoradiotherapy in a mouse model of squamous cell cancer of the head and neck

For the treatment of squamous cell cancer of the head and neck (SCCHN), the assessment of treatment response is traditionally accomplished by volumetric measurements and has been suggested to be prognostic for an eventual response to treatment. An early evaluation response during the course of radiation therapy could provide an opportunity to tailor treatment to individual patients. Diffusion magnetic resonance imaging (MRI) allows for the quantification of tissue water diffusion values, thus treatment-induced loss of tumor cells will result in the increase in water mobility at the microscopic level, which can be detected as an increase in tumor diffusion values before any volumetric changes occur. We evaluated the use of diffusion MRI as an imaging biomarker of treatment response in an orthotopic mouse model of SCCHN. Mice with murine squamous cells expressing the yeast transgene cytosine deaminase were treated with 5-fluorocytosine (5FC), ionizing radiation, and combined therapy and were compared with control animals both during and after treatment for changes in tumor volumes, diffusion values, and survival. Radiation therapy had minimal effect on volumetric growth rate, diffusion, or survival. Although 5FC and combination treatment resulted in similar reductions in tumor volumes, the combination treatment elicited a much greater increase in tumor diffusion values, which correlated with improved survival. Thus, diffusion MRI as an imaging biomarker has a potential for early evaluation of the response to chemoradiation treatment in SCCHN.

Radiosynthesis and evaluation of 5-[125I]iodoindol-3-yl-beta-D-galactopyranoside as a beta-galactosidase imaging radioligand

The synthesis and investigation of 5-[125I]iodoindol-3-yl-beta-d-galactopyranoside ([125I]IBDG) as a radioligand for single-photon emission computed tomography (SPECT) imaging of b-galactosidase expression are described. No-carrier-added [125I]IBDG was synthesized by a radioiododestannylation approach in > 75% overall radiochemical yield and > 99% radiochemical purity. [125I]IBDG was evaluated as a substrate using beta-galactosidase-expressing (D54L) and nonexpressing (D54) human glioma cell lines. A 24-hour incubation of this substrate with cultured cells revealed a 6.5-fold greater intracellular trapping of radioactivity in D54L cells compared with D54 cells. Systemic delivery of [125I]IBDG in nude mice bearing D54L tumors failed to show significant trapping of radioactivity within these tumors by SPECT imaging. In contrast, intratumoral injection of the substrate resulted in efficient trapping of radioactivity in D54L tumors but not D54 tumors, resulting in clear SPECT visualization of the former tumor. Based on dynamic SPECT imaging and blood metabolite analysis, we conclude that although [125I]IBDG is an efficient in vivo substrate for beta-galactosidase, its rapid renal clearance hampers its intratumoral availability on systemic administration.

PEGylation improves the hypoglycaemic efficacy of intranasally administered glucagon-like peptide-1 in type 2 diabetic db/db mice

AIMS

PEGylation - covalent modification of therapeutic peptides with polyethylene glycol (PEG) - is viewed as an effective way of prolonging the short lifetime of glucagon-like peptide-1 (GLP-1). In this study, we investigated the hypoglycaemic efficacies of PEGylated GLP-1s administered intranasally in type 2 diabetic db/db mice.

METHODS

Three types of site-specific (Lys(34)) PEGylated GLP-1 analogues (PEG molecular weight: 1, 2 or 5 kDa) were synthesized. Their metabolic stabilities were evaluated in nasal mucosa enzyme pools. Oral glucose tolerance test was conducted 30, 60 and 120 min after intranasally administering these analogues in type 2 diabetic db/db mice.

RESULTS

PEGylated GLP-1 analogues were found to have significantly longer half-lives than native GLP-1 in nasal mucosa enzymes (2.4-fold to 11.0-fold, p < 0.005). Non-PEGylated GLP-1 at 100 nmol/kg was not found to have marked efficacy irrespective of nasal administration time [total hypoglycaemic degree (HD(total)) values 2.8-17.3%]. On the contrary, PEGylated GLP-1s (100 nmol/kg) showed obvious efficacies with maximum HD(total) values of >51.8 +/- 5.8% (p < 0.005 vs. GLP-1).

CONCLUSION

This study highlights the pharmacological potential of intranasally administered PEGylated GLP-1s in terms of stabilizing postprandial hyperglycaemia in type 2 diabetic patients.