Surmounting Withdrawal to Initiate Fast Treatment with Naltrexone (SWIFT): A stepped wedge hybrid type 1 effectiveness-implementation study

BACKGROUND

Extended-release injectable naltrexone (XR-NTX) is an effective treatment for opioid use disorder (OUD), but initiation remains a barrier to implementation. Standard practice requires a 10- to 15-day inpatient admission prior to XR-NTX initiation and involves a methadone or buprenorphine taper followed by a 7- to 10-day washout, as recommended in the Prescribing Information for XR-NTX. A 5- to 7-day rapid induction approach was developed that utilizes low-dose oral naltrexone and non-opioid medications.

METHODS

The CTN-0097 Surmounting Withdrawal to Initiate Fast Treatment with Naltrexone (SWIFT) study was a hybrid type I effectiveness-implementation trial that compared the effectiveness of the standard procedure (SP) to the rapid procedure (RP) for XR-NTX initiation across six community inpatient addiction treatment units, and evaluated the implementation process. Sites were randomized to RP every 14 weeks in an optimized stepped wedge design. Participants (target recruitment = 450) received the procedure (SP or RP) that the site was implementing at time of admission. The hypothesis was RP will be non-inferior to SP on proportion of inpatients who receive XR-NTX, with a shorter admission time for RP. Superiority testing of RP was planned if the null hypothesis of inferiority of RP to SP was rejected.

DISCUSSION

If RP for XR-NTX initiation is shown to be effective, the shorter inpatient stay could make XR-NTX more feasible and have an important public health impact expanding access to OUD pharmacotherapy. Further, a better understanding of facilitators and barriers to RP implementation can help with future translatability and uptake to other community programs.

TRIAL REGISTRATION

NCT04762537 Registered February 21, 2021.

Effect of proton radiation therapy on cardiovascular implantable electronic devices [CIED]

Background

The number of cancer patients with CIED receiving radiotherapy has increased dramatically with improving life expectancy in both patients with cardiovascular disease and cancer. The advent of proton therapy adds new concern for potential malfunction in CIED devices, both due to significant neutron scatter and its use of strong magnets to focus radiation beams. Therefore, we aimed to assess the incidence of CIED malfunction secondary to proton therapy in this patient cohort.

Methods

We retrospectively analyzed patients with CIED undergoing proton therapy at our institute between 2011–2021. Each device was programmed pre-treatment and monitored post-treatment according to a special protocol developed in our centre. Treatments were prescribed to doses up to 70 Gy (RBE) and delivered using either passive-scattering or pencil beam techniques. Distances between the CIED and treated volumes ranged from 10–50 cm. We analyzed baseline patient demographics, CIED demographics, CIED outcomes pre-proton therapy as well as post-proton therapy including device reset and requirement for replacement, analyzing up to most recent check.

Results

Fifty-one patients with CIED underwent proton therapy during the study period. Estimated neutron dose ranged from 0.05–2.0 mSv/GyRBE for this patient cohort. Baseline demographics outlines in table 1. Of note 26/51 patients underwent proton therapy for ophthalmic malignancies, 6/51 for brain/skull malignancies. CIED comprised of 39 pacemakers and 12 implantable cardioverter defibrillators. Fourteen patients were pacemaker-dependent. Using 95% Confidence Interval, ventricular threshold, impedance, and amplitude, as well as atrial threshold and amplitude were unchanged, whereas atrial impedance measurements had a change pre- and post-proton therapy (Table 2). No patients had a device reset. One patient had a premature battery depletion three months post-radiotherapy for pancreatic cancer.

Conclusions

Our findings suggest that proton therapy does not significantly impact CIED function. Whilst caution remains as further data is accrued, close monitoring, particularly with the advent of remote monitoring, of these patients should be recommended.

Funding Acknowledgement

Type of funding sources: None.

762 Completed Cycle Audit on Treatment Escalation Planning Documentation in ENT In-Patients

Aim

Treatment Escalation Planning (TEP) helps ensure treatment foals of patients are developed understood and respected. Treatment Escalation documentation is a communication tool that provides staff immediate and accessible guidance in times of crises. A standardised form was created to improve and standardise TEP documentation in ENT in-patients. This audit aimed to review form completion rates. A further cycle was done to assess whether interventions improved practice.

Method

A retrospective audit of TEP form completion rates and quality of documentation. Paediatric patients and patients from elective surgery discharged on the same day were excluded. Data tabulated included age, co-morbidities, reason for admission, type of admission (emergency/ elective), DNACPR documentation (community and in-hospital), TEP form completion.

Results

The median age for patients included in the study was 73.5 years old. 83% were emergency admissions. Patients were multi-morbid (Malignancy, cardio and cerebro vascular disease, COPD etc.) In the first cycle 23% had in hospital DNACPR forms, 0% had community DNACPR and 0% had TEP forms completed. Intervention included staff education and physical reminders on handover documentation. Second cycle showed improvement, 40% of TEP forms were completed however 1 patient had community DNACPR in place but no in-hospital DNACPR.

Conclusions

Our intervention showed improvement in treatment escalation plan documentation. This audit also picked up a problem i.e., community DNACPR not converted to inpatient DNACPR whilst patient is an inpatient. Next steps include further intervention to improve completion rates and further audit to ensure longlasting improvement.

AB0610 SEASONAL VARIATION IN IDIOPATHIC INFLAMMATORY MYOPATHIES INCIDENCE AND PRESENTATION: A RETROSPECTIVE STUDY IN BEIJING AND HONG KONG

Background:

Seasonal patterns of disease onset and severity in idiopathic inflammatory myopathies (IIMs) as a whole are conflicting [1-3]. In recent years, over 10 myositis-specific antibodies (MSAs) have been identified. They are able to divide patients into homogenous subgroups and inform on prognosis [4].

Objectives:

The objective of the study was to investigate the seasonal variation of onset of IIMs characterised serologically.

Methods:

This was a multi-centred retrospective observational study. Consecutive Chinese patients with IIMs admitted to the rheumatology wards of the participating major regional hospitals in Beijing and Hong Kong from July 2013 to June 2018 were recruited. The diagnosis of IIMs was based on the Bohan and Peter’s criteria with definite or probable cases being included [5]. Patients with clinically amyopathic disease must have the typical Gottron’s papules or heliotrope rash as determined by rheumatologists or dermatologists, and with no symptoms or signs of muscle involvement according to Sontheimer [6]. Patients with juvenile myositis, inclusion body myositis, cancer-associated myositis and myositis associated with other connective tissue disease were excluded. A commercial line blot immunoassay kit (EUROLINE) was used to detect the MSAs.

Results:

All together 495 patients were studied. The mean age of the patients at disease onset was 48.1 years (S.D. 13.3). There was a female predominance (68.3%). The subgroups of IIMs were: dermatomyositis (61.0%), polymyositis (21.8%), clinically amyopathic dermatomyositis (12.9%), immune mediated necrotising myopathy (3.8%) and nonspecific myositis (0.4%). No particular seasonal pattern in disease onset was observed in IIM patients as a whole (Figure 1) or in any classical subgroups. However, significantly more patients with any one MSA had their disease started in the first half of the year (p=0.007) as shown in Figure 2. Patients with either anti-synthetase or anti-MDA5 antibodies, which are associated with interstitial lung disease, had more frequent disease onset from November to February, which might coincide with the local flu season. It was also found that MSA positivity was associated with infection of the patient (p=0.005). Further analyses showed that patients with MSAs which are typically associated with severe skin disease (MDA5, TIF1g, NXP2, SAE) had more hospitalisation from April to September where excessive sun exposure is expected. There were no major differences between the Beijing and Hong Kong subgroups.

Conclusion:

Apparent seasonal patterns were noticed in our ethno-serologically defined IIM patients. Certain environmental factors, particularly infection or UV exposure, could be potential triggers. Our findings could shed light on the identification of etiologic factors and enhance our understanding of disease pathogenesis.

References:

[1]Manta P, Kalfakis N, Vassilopoulos D. Evidence for Seasonal Variation in Polymyositis. Neuroepidemiology 1989;8:262–265.

[2]Phillips BA, Zilko PJ, Garlepp MJ, et al. Seasonal occurrence of relapses in inflammatory myopathies: a preliminary study. J Neurol 2002;249:441–4.

[3]Lefe R, Burgess S, Miller F, et al. Distinct Seasonal Pattern in The Onset of Adult Idiopathic Inflammatory Myopathy in Patients with Auto Antibodies Anti-Jo-1 and Anti-Signal Recognition particle. Arthritis and Rheumatism 1991;34(11):1391-1396.

[4]Tansley SL, Betterridge ZE, McHugh NJ. The diagnostic utility of autoantibodies in adult and juvenile myostis. Curt Opin Rheumatol 2013;25(6):772-777.

[5]Bohan A, Peter JB. Polymyositis and dermatomyositis. N Engl J Med 1975;292:344-347.

[6]Sontheimer RD. Clinically myopathic dermatomyositis: what can we now tell our patients? Arch Dermatol 2010;146(1):76-80.

Disclosure of Interests:

None declared

iPSC modeling of young-onset Parkinson's disease reveals a molecular signature of disease and novel therapeutic candidates

Young-onset Parkinson's disease (YOPD), defined by onset at <50 years, accounts for approximately 10% of all Parkinson's disease cases and, while some cases are associated with known genetic mutations, most are not. Here induced pluripotent stem cells were generated from control individuals and from patients with YOPD with no known mutations. Following differentiation into cultures containing dopamine neurons, induced pluripotent stem cells from patients with YOPD showed increased accumulation of soluble α-synuclein protein and phosphorylated protein kinase Cα, as well as reduced abundance of lysosomal membrane proteins such as LAMP1. Testing activators of lysosomal function showed that specific phorbol esters, such as PEP005, reduced α-synuclein and phosphorylated protein kinase Cα levels while increasing LAMP1 abundance. Interestingly, the reduction in α-synuclein occurred through proteasomal degradation. PEP005 delivery to mouse striatum also decreased α-synuclein production in vivo. Induced pluripotent stem cell-derived dopaminergic cultures reveal a signature in patients with YOPD who have no known Parkinson's disease-related mutations, suggesting that there might be other genetic contributions to this disorder. This signature was normalized by specific phorbol esters, making them promising therapeutic candidates.

Abstract NT-105: ANTI-TUMOUR EFFECTS OF ALL-TRANS RETINOID ACID, AN ANNEXIN A2-S100A10 PATHWAY INHIBITOR ON SEROUS OVARIAN CANCER

Annexin A2 is increased in serous ovarian cancer and plays an essential role in ovarian cancer invasion and metastasis. In combination with S100A10, annexin A2 plays an important role in the plasminogen activator system regulating plasmin production. The aim of this study was to investigate the potential utility of all-trans retinoid acid (ATRA), an inhibitor of the annexin A2-S100A10 signalling pathway, as a new therapeutic against serous ovarian cancer. Survival of serous ovarian cancer cells (OVCAR-3, OV-90, & OAW28) was significantly decreased by ATRA treatment (1-5µM). ATRA (1µM) also significantly decreased proliferation (Ki67 positivity, p=0.0034), S100A10 protein levels (p=0.0273), and increased cell apoptosis (cleaved caspase-3 positivity, p=0.0024) in serous ovarian cancer tissues using an ex vivo explant assay. In OAW28 cells, reduced cell survival following ATRA treatment was associated with a reduction of S100A10 protein levels, S100A10 and annexin A2 membrane localization, plasmin generation, motility and invasion. In contrast, ATRA inhibited OV-90 cell survival and invasion but did not affect plasmin activation or S100A10 and annexin A2 membrane localization or protein levels. These findings suggest that ATRA inhibits serous ovarian cancer proliferation and invasion via both S100A10 dependant and S100A10 independent mechanisms. Our results show that ATRA has promising potential as a novel therapy against serous ovarian cancer that warrants further evaluation.

Citation Format: Noor A Lokman,Rachel Ho, Kavyadharshini Gunasegaran, Wendy M Bonner , Martin K Oehler, Carmela Ricciardelli. ANTI-TUMOUR EFFECTS OF ALL-TRANS RETINOID ACID, AN ANNEXIN A2-S100A10 PATHWAY INHIBITOR ON SEROUS OVARIAN CANCER [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr NT-105.

Thoracic kyphosis assessment in postmenopausal women: an examination of the Flexicurve method in comparison to radiological methods

The Flexicurve ruler is an alternative method to radiographs for measuring thoracic kyphosis (curvature), but it is not certain that it is comparable. This study shows that Flexicurve can estimate radiographic vertebral centroid angles with less error than Cobb angles but that its accuracy would be inadequate for most clinical purposes.

INTRODUCTION

The Flexicurve ruler provides a non-radiological method of measuring thoracic kyphosis (TK) that has moderately strong correlations with the gold-standard radiographic Cobb angle method, while consistently underestimating the TK angle. Cobb angles can include measurement errors that may contribute to poor agreement, particularly in older populations. The vertebral centroid angle could be a better radiographic reference method for the validation of Flexicurve. Using two separate radiographic measurements of TK, we examined the validity of Flexicurve. We aimed to ascertain the level of agreement between measures and to empirically explore reasons for between-method differences.

METHODS

TK angles determined using Flexicurve and radiographic Cobb and vertebral centroid methods were compared using data from 117 healthy postmenopausal women (mean (SD) age 61.4 (7.0) years). Bland and Altman plots were used to assess differences between methods. Age, bone mineral density and body mass index were examined as characteristics that might explain any differences.

RESULTS

Flexicurve angles were scaled prior to analysis. There was no statistically significant difference between angles produced by Flexicurve and vertebral centroid methods (MD - 2.16°, 95%CI - 4.35° to 0.03°) although differences increased proportionally with TK angles. Flexicurve angles were significantly smaller than radiographic Cobb angles and depending on the scaling method used, systematic error ranged between - 2.48° and - 5.19°. Age accounts for some of the differences observed (R² < 0.08, p < 0.005).

CONCLUSIONS

TK measured using the Flexicurve shows better agreement with the radiographic vertebral centroid method, but inaccuracy of the Flexicurve increases with increasing angle of kyphosis.

Anti-tumour effects of all-trans retinoid acid on serous ovarian cancer

Background

Annexin A2 is increased in serous ovarian cancer and plays an essential role in ovarian cancer invasion and metastasis. In combination with S100A10, annexin A2 plays an important role in the plasminogen activator system regulating plasmin production. The aim of this study was to investigate the potential utility of all-trans retinoid acid (ATRA), an inhibitor of the annexin A2-S100A10 signalling pathway, as a new therapeutic against serous ovarian cancer.

Methods

In this study we determined the effects of ATRA treatment (1-5 μM) on annexin A2 and S100A10 expression, plasmin activation, and the ability of ATRA to inhibit serous ovarian cancer cell survival, motility and invasion in vitro. We also employed an ex vivo tissue explant assay to assess response to ATRA treatment in serous ovarian cancers. Cryopreserved serous ovarian cancer tissues were cultured on gelatin sponges for 72 h with ATRA (1 μM). Effects on apoptosis and proliferation were assessed by immunohistochemistry using antibodies to cleaved caspase 3 or Ki67, respectively.

Results

Survival of serous ovarian cancer cells (OVCAR-3, OV-90, & OAW28) was significantly decreased by ATRA treatment (1-5 μM). ATRA (1 μM) also significantly decreased proliferation (Ki67 positivity, p = 0.0034), S100A10 protein levels (p = 0.0273), and increased cell apoptosis (cleaved caspase-3 positivity, p = 0.0024) in serous ovarian cancer tissues using the ex vivo tissue explant assay. In OAW28 cells, reduced cell survival following ATRA treatment was associated with a reduction of S100A10 mRNA and protein levels, S100A10 and annexin A2 membrane localization, plasmin generation, motility and invasion. In contrast, ATRA inhibited OV-90 cell survival and invasion but did not affect plasmin activation or S100A10 and annexin A2 expression or membrane localization.

Conclusions

These findings suggest that ATRA inhibits serous ovarian cancer proliferation and invasion via both S100A10 dependant and S100A10 independent mechanisms. Our results show that ATRA has promising potential as a novel therapy against serous ovarian cancer that warrants further evaluation.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-1017-7) contains supplementary material, which is available to authorized users.

Biosynthesis of 1α-hydroxycorticosterone in the winter skate Leucoraja ocellata: evidence to suggest a novel steroidogenic route

The present study explores the ability of intracellular bacteria within the renal-inter-renal tissue of the winter skate Leucoraja ocellata to metabolize steroids and contribute to the synthesis of the novel elasmobranch corticosteroid, 1α-hydroxycorticosterone (1α-OH-B). Despite the rarity of C1 hydroxylation noted in the original identification of 1α-OH-B, literature provides evidence for steroid C1 hydroxylation by micro-organisms. Eight ureolytic bacterial isolates were identified in the renal-inter-renal tissue of L. ocellata, the latter being the site of 1α-OH-B synthesis. From incubations of bacterial isolates with known amounts of potential 1α-OH-B precursors, one isolate UM008 of the genus Rhodococcus was seen to metabolize corticosteroids and produce novel products via HPLC analysis. Cations Zn²⁺ and Fe³⁺ altered metabolism of certain steroid precursors, suggesting inhibition of Rhodococcus steroid catabolism. Genome sequencing of UM008 identified strong sequence and structural homology to that of Rhodococcus erythropolis PR4. A complete enzymatic pathway for steroid-ring oxidation as documented within other Actinobacteria was identified within the UM008 genome. This study highlights the potential role of Rhodococcus bacteria in steroid metabolism and proposes a novel alternative pathway for 1α-OH-B synthesis, suggesting a unique form of mutualism between intracellular bacteria and their elasmobranch host.

C9orf72 is required for proper macrophage and microglial function in mice

Expansions of a hexanucleotide repeat (GGGGCC) in the noncoding region of the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Decreased expression of C9orf72 is seen in expansion carriers, suggesting that loss of function may play a role in disease. We found that two independent mouse lines lacking the C9orf72 ortholog (3110043O21Rik) in all tissues developed normally and aged without motor neuron disease. Instead, C9orf72 null mice developed progressive splenomegaly and lymphadenopathy with accumulation of engorged macrophage-like cells. C9orf72 expression was highest in myeloid cells, and the loss of C9orf72 led to lysosomal accumulation and altered immune responses in macrophages and microglia, with age-related neuroinflammation similar to C9orf72 ALS but not sporadic ALS human patient tissue. Thus, C9orf72 is required for the normal function of myeloid cells, and altered microglial function may contribute to neurodegeneration in C9orf72 expansion carriers.

A low-power, high-speed, 9-channel germanium-silicon electro-absorption modulator array integrated with digital CMOS driver and wavelength multiplexer

We demonstrate the first germanium-silicon C-band electro-absorption based waveguide modulator array and echelle-grating-based silicon wavelength multiplexer integrated with a digital CMOS driver circuit. A 9-channel, 10Gbps SiGe electro-absorption wavelength-multiplexed modulator array consumed a power of 5.8mW per channel while being modulated at 10.25Gbps by 40nm CMOS drivers delivering peak-to-peak voltage swings of 2V, achieving a modulation energy-efficiency of ~570fJ/bit including drivers. Performance up to 25Gbps on a single-channel SiGe modulator and CMOS driver is also reported.

MO-F-213AB-05: Commissioning of Gated RapidArc Radiotherapy for Treatment of Moving Targets

PURPOSE

To commission and evaluate gated RapidArc radiotherapy of a linear accelerator (Varian TrueBeam) for treatment of moving targets using a programmable dynamic phantom.

METHODS

The phantom used had different dosimetry inserts for measurement of dose and dose distribution. It could be programmed to move in the anterior-posterior and superior-inferior axes with different motion patterns, amplitudes and frequencies to simulate lung motions of patients. A set of 4D CT images was acquired with the aid of a Varian RPM system. Images acquired at the 40, 50 and 60% of the motion cycle were selected and transferred to a treatment planning system (Varian Eclipse) for planning. A two-arc RapidArc treatment plan was generated for a C-shaped target volume with a conformity index of 1.49 and transferred to the TrueBeam for treatment delivery. Dose and dose distribution measurements were performed using a 0.057 cc ionization chamber and radiochromic films, respectively and compared with the TPS calculations. Five treatment fractions were given in three days with two different target motion patterns to assess the consistency of the dose delivery.

RESULTS

Agreement between TPS calculation and measurement were within 1.64% for dose and 3% or 3mm in distance to agreement for dose distribution. Repeatability of dose delivery between treatments was within 0.1% (1SD) in the five treatment fractions delivered in three days. The time required to deliver a dose of 2 Gy to a moving C-shaped target using gated RapidArc technique with two gantry rotations was about 15 minutes.

CONCLUSIONS

The geometric and dosimetric accuracy and consistency of gated RapidArc radiotherapy had been verified. Our study indicated that the accuracy and consistency of the treatment modality were acceptable for clinical implementation.

Antioxidant potential and radical-scavenging effects of flavonoids from the leaves of Psidium cattleianum grown in French Polynesia

Psidium cattleianum J. Sabine (Myrtaceae) is a traditional medicinal plant in French Polynesia. The leaves and roots possess many medicinal properties. These effects may be correlated with the presence of antioxidant compounds. Seven flavonoids along with a benzoic acid were isolated from the leaves of P. cattleianum. The compounds indicated strong antioxidant and radical-scavenging activities in ALP, DPPH(·), ABTS(·-) and ORAC assays. This study demonstrates that the leaves of P. cattleianum possess main compounds with interesting antioxidant and radical-scavenging activities, as clarified by four biological assays. Our findings may justify the use of these leaves in the traditional medicine of French Polynesia. Among the total eight known compounds, reynoutrin and luteolin were isolated for the first time from the genus Psidium.

Use of Parotid Pressure Bandage for Drainless Parotidectomies: A Modification of an Old Technique

Objective: The use of fibrin glue has been described in parotidectomies to obviate the need for drains. However, the seroma rate postoperatively can be high. We have modified this technique so as to achieve the same successes without the seroma.

Method: A prospective, randomized, case-control study on 54 patients undergoing superficial parotidectomies. All patients had fibrin glue sprayed on the parotid bed intraoperatively. In group A, a pressure bandage was applied over the parotid area for 12 hours postoperatively. In group B, no pressure bandage was used.

Results: Group A patients stayed an average of 1.1 days postoperatively while Group B patients stayed 1.6 days. The cost savings in terms of hospitalization was $150 for group A patients. The seroma rate detected postoperatively was 10% for Group A patients but 53% in Group B patients. Among all patients with seromas, the average volume of parotid tissue removed was significantly higher at 71 cm3 compared with patients without seroma, whose average volume of parotid tissue removed was 44 cm3.

Conclusion: This paper has shown that it is safer and cheaper to perform parotid surgery with fibrin glue and a parotid bandage. The rate of seroma is related to the volume of parotid tissue removed.

A 10-Year Review of Laryngeal Cysts in an Asian Pediatric Population

Objective: 1) Evaluate the presentation and treatment of pediatric laryngeal cysts in an Asian population.2) Determine the success rates of surgery, and recommend a preferred surgical method.

Method: A 10-year (2000-2010) retrospective analysis of the operative records of patients with laryngeal cysts at a tertiary children’s hospital in Singapore. A total of 29 patients were identified. All underwent microlaryngobronchoscopy under general anesthesia. We recorded the following: birth history, symptoms, operative details, and recurrence.

Results: Of the 29 children, 18 were boys, and 11 were girls. Only 8 children were preterm. Most of the children presented within the first 2 years of life. The 3 most common symptoms were stridor, respiratory distress, and hoarseness. There was a large proportion of patients with vallecular cysts (n = 14), accounting for nearly half of the cases. This is one of the largest published series to our knowledge. The most common treatment modalities used were CO2 laser marsupialization in 20 patients and excision with cold steel in 7 patients. Recurrence was documented in 4 patients (13.8%).

Conclusion: We recommend that laryngeal cysts in children should be removed surgically, due to the risk of airway obstruction. Our preference is carbon dioxide laser marsupialization during microlaryngobronchoscopy. There is a low recurrence rate, and there were no postoperative complications in our study.

Esthesioneuroblastomas in an Asian Population: Similarities and Differences

Objective: Esthesioneuroblastomas is an uncommon malignant tumor of the olfactory neuroepithelium in the white population. However, in our series with predominantly Asian patients, it is the most common anterior skull base malignancy requiring a craniofacial resection.

Method: Twenty-four patients who underwent craniofacial resections for malignant anterior skull base tumors and were diagnosed with esthesioneuroblastomas were recruited in this prospective study over a 10-year period. All patients were operated on by the same surgeon with the same technique.

Results: Twenty-four out of 48 patients with anterior skull base malignancies had esthesioneuroblastomas. The mean age of patients with esthesioneuroblastomas was 53 years old with no bimodal distribution. Most patients were Chinese (92%) with a male predominance (62%). Major complication rate was 13% and we had 1 unrelated perioperative mortality. Fifty percent of our patients had either local or regional recurrence. Three patients passed away in our series from tumor-unrelated reasons. Two-thirds of the patients in our series are alive more than 5 years after the initial diagnosis. The overall 5 year survival rate was 86%.

Conclusion: The predominant malignant anterior skull base tumor requiring a craniofacial resection was an esthesioneuroblastoma (50%). This is much more common than described in other series. There is a good curability with this tumor, with most patients surviving well beyond 5 years.

Exercise is the primary factor associated with Hsp70 induction in muscle of treadmill running rats

AIM

The cytoprotective, inducible stress protein, Hsp70, increases in muscles of rodents subjected to strenuous treadmill running. Most treadmill running protocols employ negative reinforcement to encourage animals to exercise. As these stimuli may themselves activate stress responses, the present investigation was conducted to determine their contribution to the exercise-induced expression of Hsp70.

METHODS

Twenty-one male Sprague-Dawley rats were randomly divided into three equal groups including an exercise group (EX), which ran on a treadmill at 30 m min(-1) for 60 min; a stimulation group (STIM), which was not allowed to run, but was stimulated with compressed air and mild electric shock concurrently with their exercising cohort; and a control group (CON), which was housed in the treadmill room during the exercise period. Animals were killed 24 h post-experiment and hearts (H), soleii (SOL) and white gastrocnemii (WG) were harvested and analysed for Hsp70 content (mean% +/- SEM of standard).

RESULTS

Significant increases in Hsp70 (as a % of standard) were noted in H and WG (H = 77.4 +/- 8.5; WG = 93.9 +/- 18.4) of EX but not in STIM (H = 32.5 +/- 4.6; WG = 32.0 +/- 3.4) or CON (H = 20.5 +/- 3.7; WG = 32.4 +/- 7.4). In SOL, Hsp70 expression in EX (126.7 +/- 6.2) was different from STIM (98.3 +/- 10.9) only. This occurred, despite the fact that all groups were exposed to a stressful environment and exhibited elevated (P < 0.001) temperatures (EX -41.2 +/- 0.1 degrees C > STIM -40.5 +/- 0.2 degrees C > CON -39.0 +/- 0.1 degrees C) indicative of a general stress response.

CONCLUSIONS

These data suggest that exercise per se, rather than environmental conditions or noxious stimuli, are responsible for the induction of Hsp70 in rat muscle during treadmill running.

Phase I pharmacokinetic (PK) and pharmacodynamic (PD) study of 17-Allylamino-17-demethoxygeldanamycin (17AAG) in children with solid tumors

9022

Background: 17AAG is a benzoquinone ansamycin that binds to heat shock protein 90 (Hsp90) and alters levels of cancer-associated proteins that are regulated by Hsp90. 17AAG has been well-tolerated in adults, but has not previously been administered to children. Methods: A Phase I study of 17AAG was initiated to define the maximally tolerated dose and toxicity profile of this drug in children. PK and PD were also studied. Cohorts of 3–6 patients with recurrent or refractory solid tumors were treated every 21 days with escalating doses of 17AAG twice weekly for two weeks. Plasma PK of 17AAG and its major metabolite, 17AG, were measured on day 1 by HPLC. Changes in levels of the inducible isoform of Hsp70 were assessed by Western blot using peripheral blood mononuclear cells (PBMCs) obtained 24 h after the 17AAG infusion. Actin was measured for comparison. Because 17AAG is a substrate for CYP3A4/5 and MDR1, pharmacogenetic analyses have been undertaken to determine if genotypes including CYP3A4*1B, CYP3A5*3, and MDR1 G2677T/A and C3435T influence 17AAG disposition. Results: 12 pts (median age 11 years, range 5–18) with neuroblastoma (5), osteosarcoma (4), Ewing’s family tumors (2), and desmoplastic small round cell tumor (1) have been treated with 17AAG. An MTD has yet to be defined though one dose limiting toxicity (Grade 3 hypoxia) was observed at Dose Level 4 (360 mg/m2). The AUC of 17AAG increased with dose, with a linear relationship between end of infusion 17AAG plasma concentration and AUC. The AUC of 17AAG increased with dose, with a linear relationship between end of infusion 17AAG plasma concentration and AUC. Clearance ranged between 12.5 and 29.6 l/hr/m2 (median, 21.6 l/h/m2) and did not change with increasing doses. Post-treatment increases in Hsp70 in PBMCs have been observed in pts treated with 17AAG doses at or above 150 mg/m2. Declines in Akt and IGF1R in PBMCs have been seen in some but not all pts following treatment. Conclusions: 17AAG is well tolerated in children at dose levels studied to date. 17AAG dose escalation continues and at the time of the meeting, updated data will be reported.

No significant financial relationships to disclose.

Irofulven as first line therapy in recurrent or metastatic gastric cancer: a phase II multicenter study by the Cancer Therapeutics Research Group (CTRG)

BACKGROUND

The purpose of this study was to evaluate the tolerability and efficacy of irofulven, a DNA interacting acylfulvene analog, as first line therapy for patients with recurrent or metastatic gastric cancer.

PATIENTS AND METHODS

Twenty-three patients with recurrent or metastatic gastric cancer received irofulven at a dose of 0.45 mg/kg administered intravenously over 30-min infusion (up to a maximum of 50 mg), on days 1 and 8, every 3 weeks.

RESULTS

The median number of cycles delivered per patient was 2 (range 1-6). Two patients (9%) had >or= 1-week delay in administration of subsequent cycle of chemotherapy. For the day 8 chemotherapy, dose reductions were required in seven patients (30%); dose omitting occurred in five patients (22%). Grade 3/4 anemia and neutropenia occurred in 22 and 17% of patients, respectively. There was no grade 4 thrombocytopenia and no neutropenic fever was observed. Of the 20 evaluable patients, there were no responses observed, 3 patients had stable disease after 2 cycles of treatment which was not confirmed by a further assessment. Median overall survival was 6.05 months (95% CI 4.55-9.39).

CONCLUSIONS

Irofulven was tolerated at the dose of 0.45 mg/kg on days 1 and 8, every 3 weeks but showed no evidence of antitumor activity in patients with advanced gastric cancer.

Erectile function of Chinese men with schizophrenia in psychiatric out-patient clinics and their attitude towards treatment

Background: Antipsychotics had been shown to cause erectile dysfunction (ED). This study aims to determine the rate and degree of ED in Chinese males who had chronic schizophrenia and were taking antipsychotic agents for at least four weeks in an outpatient psychiatric clinic in Hong Kong. Method: Seventy Chinese males with chronic schizophrenia attending the clinic were surveyed on the five aspects of erectile function using the International Index of Erectile Function Scale (IIEF-15). Their attitude on receiving treatment for any ED was also elicited using a standard attitude questionnaire. Results: Fifty-eight per cent of married subjects had an IIEF-15 score below the cut off point for normal erectile function, although married subjects had a higher mean score than the single or divorced subjects. There was no significant difference in total IIEF-15 score between subjects on different antipsychotics. The score also showed no significant correlation with the duration of medication. Most subjects preferred psychotherapy to sildenafil for treatment of their sexual dysfunction. Conclusion: The majority of Chinese males with schizophrenia and maintained on antipsychotic drugs in the outpatient clinic had sub-optimal erectile function. Psychological management was the treatment of choice for their dysfunction.

Acute isovolemic anemia does not impair peripheral or central nerve conduction

BACKGROUND

Previous studies have found subtle slowing of responses in tests of addition and digit-symbol substitution during acute severe isovolemic anemia to a hemoglobin concentration of 5 g/dl in healthy unmedicated humans. In this study, the authors tested the hypothesis that such changes relate to the slowing of afferent neural traffic.

METHODS

The median nerve was stimulated at the wrist in seven healthy unmedicated volunteers before and after induction of acute isovolemic anemia to a nadir hemoglobin concentration of 5.1 +/- 0.3 g/dl (mean +/- SD). Times for neural impulses to travel from the stimulus site to the brachial plexus, cervical spinal cord, and cerebral cortex were measured using somatosensory evoked potentials. Tests were repeated during acute anemia with the subject breathing oxygen. As a control for time and intrasubject variation, the testing was repeated on a separate day when anemia was not produced at times equivalent to those on the experimental day.

RESULTS

Induced acute severe isovolemic anemia decreased nerve conduction latencies from the wrist to the contralateral cerebral cortex (i.e., to the N20 peak) by 2.3 +/- 1.6% compared with values at a mean hemoglobin concentration of 12.7 g/dl (P < 0.01). These decreased latencies were due solely to an increased peripheral conduction velocity, from the wrist to the brachial plexus (P < 0.05), and were not altered when subjects breathed oxygen (P > 0.05). Conduction velocity from the brachial plexus or cervical spinal cord to the cerebral cortex did not change with acute anemia (P > 0.05). Latencies did not differ on the control day among the times of testing (all P > 0.05), nor did they differ at baseline between the control and experimental days (all P > 0.05).

CONCLUSION

Somatosensory evoked potential latencies were not increased by acute severe isovolemic anemia, making it unlikely that the afferent portion of the neural system is responsible for slowing of cognitive responses previously observed during acute anemia. Because severe isovolemic anemia did not increase somatosensory evoked potential latencies, etiologies other than anemia should be sought if latencies are increased during intraoperative monitoring.

Short and long-term outcome of pancreatic surgery in a district general hospital

Pancreatic surgery is a formidable undertaking with historically high mortality and poor prognosis for periampullary lesions. This has led to recommendations that all pancreatic surgery should be performed in specialist centres. There is no doubt from large series that a low mortality can be achieved in these centres, but there has been no direct comparison between results from these specialist centres and district general hospitals with an interest in pancreatic disease. We present a retrospective, seven-year experience with a 3% 30 day mortality, 39% morbidity and 14 month median survival for malignant disease. Comparison with the UK survey of specialist pancreatic units shows that pancreatic surgery can be safely performed in the setting of a district general hospital with low morbidity and mortality, and good long-term outcome.

Oxygen reverses deficits of cognitive function and memory and increased heart rate induced by acute severe isovolemic anemia

BACKGROUND

Erythrocytes are transfused to improve oxygen delivery and prevent or treat inadequate oxygenation of tissues. Acute isovolemic anemia subtly slows human data processing and degrades memory, increases heart rate, and decreases self-assessed energy level. Erythrocyte transfusion is efficacious in reversing these effects of acute anemia. We tested the hypothesis that increasing arterial oxygen pressure (Pao2) to 350 mmHg or greater would supply sufficient oxygen to be equivalent to augmenting hemoglobin concentration by 2-3 g/dl and thus reverse the effects of acute anemia.

METHODS

Thirty-one healthy volunteers, aged 28 +/- 4 yr (mean +/- SD), were tested with verbal memory and standard, computerized neuropsychologic tests before and twice after acute isovolemic reduction of their hemoglobin concentration to 5.7 +/- 0.3 g/dl. Two sets of tests were performed in randomized order at the lower hemoglobin concentration: with the volunteer breathing room air or oxygen. The subject and those administering the tests and recording the results were unaware which gas was administered. As an additional control for duration of the experiment, 10 of these volunteers also completed the same tests on a separate day, without alteration of hemoglobin concentration, at times of the day similar to those on the experimental day. Heart rate, mean arterial blood pressure, and self-assessed sense of energy were recorded at the time of each test.

RESULTS

Reaction time for digit-symbol substitution test increased, delayed memory was degraded, mean arterial pressure and energy level decreased, and heart rate increased at a hemoglobin concentration of 5.7 g/dl (all P < 0.05). Increasing Pao2 to 406 +/- 47 mmHg reversed the digit-symbol substitution test result and the delayed memory changes to values not different from those at the baseline hemoglobin concentration of 12.7 +/- 1.0 g/dl, and decreased heart rate (P < 0.05). However, mean arterial pressure and energy level changes were not altered with increased Pao2 during acute anemia.

CONCLUSION

The authors confirmed that acute isovolemic anemia subtly slows human reaction time, degrades memory, increases heart rate, and decreases energy level. The findings of this study support the hypothesis that increasing Pao2 to 350 mmHg or greater by breathing oxygen reverses all of these effects of acute anemia except for decreased energy.

Improved precision of quantitating calcium in biological electron probe analysis

We describe the use of direct multiple least-squares fitting of (unfiltered) biological X-ray spectra. Test of this method on computer-generated spectra and experimental specimens shows that, for the average biological specimen, direct fitting improves the precision of Ca measurements by an approximate factor of 1.6 for a given electron dose. The influence of non-statistical, instrumental sources of measurement errors is considered, and we show a simple method for reducing the effect of these sources of error in the directly fitted spectra.

Adenocarcinoma of the small bowel

Cancer of the small bowel is a rare entity but its incidence is rising. Historically, outcome is poor despite apparent curative resection. At present surgery remains the only treatment modality of proven benefit in the management of this disease. Recent data would suggest 5-year survival rates in the order of 40-50% at all sites of small bowel cancer. To improve upon this, earlier diagnosis with a high index of suspicion and multicentre adjuvant therapy trials are required.

Resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in neuroblastoma cells correlates with a loss of caspase-8 expression

Disruption of apoptotic pathways may be involved in tumor formation, regression, and treatment resistance of neuroblastoma (NB). Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent inducer of apoptosis in cancer cell lines, whereas normal cells are not sensitive to TRAIL-mediated apoptosis. In this study we analyzed the expression and function of TRAIL and its agonistic and antagonistic receptors as well as expression of cellular FLICE-like inhibitory protein and caspase-2, -3, -8, -9, and -10 in 18 NB cell lines. Semiquantitative RT-PCR revealed that TRAIL-R2 and TRAIL-R3 are the main TRAIL-receptors used by NB cells. Sensitivity to TRAIL-induced apoptosis did not correlate with mRNA expression of TRAIL receptors or cellular FLICE-like inhibitory protein. Surprisingly, caspase-8 and caspase-10 mRNA expression was detected in only 5 of 18 NB cell lines. Interestingly, only these five NB cell lines were susceptible to TRAIL-induced apoptosis in a time- and dose-dependent manner. Treatment with 5-aza-2'-deoxycytidine restored mRNA and protein expression of caspase-8 and TRAIL sensitivity of resistant cell lines, suggesting that gene methylation is involved in caspase inactivation. The TRAIL system seems to be functional in NB cells expressing caspase-8 and/or caspase-10. Because many cytotoxic drugs induce caspase-dependent apoptosis, failure to express caspase-8 and/or caspase-10 might be an important mechanism of resistance to chemotherapy in NB.

Roles of active site and novel K+ ion-binding site residues in human mitochondrial branched-chain alpha-ketoacid decarboxylase/dehydrogenase

The human mitochondrial branched-chain alpha-ketoacid decarboxylase/dehydrogenase (BCKD) is a heterotetrameric (alpha(2)beta(2)) thiamine diphosphate (TDP)-dependent enzyme. The recently solved human BCKD structure at 2.7 A showed that the two TDP-binding pockets are located at the interfaces between alpha and beta' subunits and between alpha' and beta subunits. In the present study, we show that the E76A-beta' mutation results in complete inactivation of BCKD. The result supports the catalytic role of the invariant Glu-76-beta' residue in increasing basicity of the N-4' amino group during the proton abstraction from the C-2 atom on the thiazolium ring. A substitution of His-146-beta' with Ala also renders the enzyme completely inactive. The data are consistent with binding of the alpha-ketoacid substrate by this residue based on the Pseudomonas BCKD structure. Alterations in Asn-222-alpha, Tyr-224-alpha, or Glu-193-alpha, which coordinates to the Mg(2+) ion, result in an inactive enzyme (E193A-alpha) or a mutant BCKD with markedly higher K(m) for TDP and a reduced level of the bound cofactor (Y224A-alpha and N222S-alpha). Arg-114-alpha, Arg-220-alpha, and His-291-alpha interact with TDP by directly binding to phosphate oxygens of the cofactor. We show that natural mutations of these residues in maple syrup urine disease (MSUD) patients (R114W-alpha and R220W-alpha) or site-directed mutagenesis (H291A-alpha) also result in an inactive or partially active enzyme, respectively. Another MSUD mutation (T166M-alpha), which affects one of the residues that coordinate to the K(+) ion on the alpha subunit, also causes inactivation of the enzyme and an attenuated ability to bind TDP. In addition, fluorescence measurements establish that Trp-136-beta in human BCKD is the residue quenched by TDP binding. Thus, our results define the functional roles of key amino acid residues in human BCKD and provide a structural basis for MSUD.

Different effects of TrkA expression in neuroblastoma cell lines with or without MYCN amplification

BACKGROUND

Expression of the neurotrophin receptor TrkA is associated with a favorable prognosis in neuroblastoma (NB) and promotes growth inhibition and neuronal differentiation. Aggressive, MYCN-amplified NB tumors express little or no TrkA mRNA, suggesting that MYCN overexpression may inhibit TrkA expression.

PROCEDURE

To study the interactions of TrkA expression and MYCN amplification in NB, we stably expressed the TrkA receptor in the MYCN single copy cell lines SH-SY5Y and NB69 as well as in the MYCN amplified cell lines CHP134 and IMR5.

RESULTS

All four transfected cell lines demonstrated high TrkA expression and similar activation of the TrkA receptor and of mitogen-activated protein kinases as well as induction of immediate-early genes in response to nerve growth factor (NGF). Introduction of TrkA restored NGF responsiveness of SH-SY5Y and NB69 cells, as demonstrated by morphologic differentiation, growth inhibition, and enhanced survival in serum-free medium. However, no morphologic, growth, or survival responses to NGF were detected in MYCN-amplified CHP134 and IMR5 TrkA transfectants.

CONCLUSIONS

Thus, transfection of TrkA into MYCN amplified NB cell lines only partly restored the TrkA/NGF signaling pathway, suggesting additional inhibitory effects of MYCN overexpression on TrkA signaling.

Subcutaneous perfusion and oxygen during acute severe isovolemic hemodilution in healthy volunteers

HYPOTHESIS

Acute severe isovolemic anemia (to a hemoglobin [Hb] concentration of 50 g/L) does not decrease subcutaneous wound tissue oxygen tension (PsqO(2)).

SETTING

University hospital operating room and inpatient general clinical research center ward.

SUBJECTS

Twenty-five healthy, paid volunteers.

METHODS

Subcutaneous oxygen tension and subcutaneous temperature (Tsq) were measured continuously during isovolemic hemodilution to an Hb level of 50 g/L. In 14 volunteers (initially well-perfused), "normal" perfusion (Tsq >34.4 degrees C) was achieved by hydration and systemic warming prior to starting isovolemic hemodilution, while in 11 volunteers (perfusion not controlled [PNC]), no attempt was made to control perfusion prior to hemodilution.

MAIN OUTCOME MEASURES

Measurements of PsqO(2), Tsq, and relative subcutaneous blood flow (flow index).

RESULTS

While PsqO(2), Tsq, and flow index were significantly lower in PNC vs well-perfused subjects at baseline, there was no significant difference between them at the Hb of 50 g/L (nadir). Subcutaneous PO(2) did not decrease significantly in either group. Arterial PO(2) was not different between the groups, and did not change significantly over time; Tsq and flow index increased significantly from baseline to nadir Hb in both groups.

CONCLUSIONS

The level of PsqO(2) was maintained at baseline levels during hemodilution to Hb 50 g/L in healthy volunteers, whether they were initially well-perfused or mildly underperfused peripherally. Given the significant increase in Tsq and flow index, this resulted from a compensatory increase in subcutaneous blood flow sufficient to maintain oxygen delivery. Wound healing depends to a large extent on tissue oxygen delivery, and these data suggest that even severe anemia by itself would not be sufficient to impair wound healing. Thus, transfusion of autologous packed red blood cells solely to improve healing in surgical patients with no other indication for transfusion is not supported by these results.