Local hero: A phase II study of local therapy only (stereotactic radiosurgery and / or surgery) for treatment of up to five brain metastases from HER2+ breast cancer. (TROG study 16.02)

Introduction, A decade ago, stereotactic radiosurgery (SRS) without whole brain radiotherapy (WBRT) was emerging as preferred treatment for oligometastatic brain metastases. Studies of cavity SRS after neurosurgery were underway. Data specific to metastatic HER2 breast cancer (MHBC), describing intracranial, systemic and survival outcomes without WBRT, were lacking. A Phase II study was designed to address this gap. Method, Adults with MHBC, performance status 0-2, ≤ five BrM, receiving/planned to receive HER2-targeted therapy were eligible. Exclusions included leptomeningeal disease and prior WBRT. Neurosurgery allowed ≤6 weeks before registration and required for BrM >4 cm. Primary endpoint was 12-month requirement for WBRT. Secondary endpoints; freedom from (FF-) local failure (LF), distant brain failure (DBF), extracranial disease failure (ECDF), overall survival (OS), cause of death, mini-mental state examination (MMSE), adverse events (AE). Results, Twenty-five patients accrued Decembers 2016-2020. The study closed early after slow accrual. Thirty-seven BrM and four cavities received SRS. Four cavities and five BrM were observed. At 12 months: one patient required WBRT (FF-WBRT 95 %, 95 % CI 72-99), FFLF 91 % (95 % CI 69-98), FFDBF 57 % (95 % CI 34-74), FFECDF 64 % (95 % CI 45-84), OS 96 % (95 % CI 74-99). Two grade 3 AE occurred. MMSE was abnormal for 3/24 patients at baseline and 1/17 at 12 months. Conclusion, At 12 months, SRS and/or neurosurgery provided good control with low toxicity. WBRT was not required in 95 % of cases. This small study supports the practice change from WBRT to local therapies for MHBC BrM.

GDF15 linked to maternal risk of nausea and vomiting during pregnancy

GDF15, a hormone acting on the brainstem, has been implicated in the nausea and vomiting of pregnancy, including its most severe form, hyperemesis gravidarum (HG), but a full mechanistic understanding is lacking1-4. Here we report that fetal production of GDF15 and maternal sensitivity to it both contribute substantially to the risk of HG. We confirmed that higher GDF15 levels in maternal blood are associated with vomiting in pregnancy and HG. Using mass spectrometry to detect a naturally labelled GDF15 variant, we demonstrate that the vast majority of GDF15 in the maternal plasma is derived from the feto-placental unit. By studying carriers of rare and common genetic variants, we found that low levels of GDF15 in the non-pregnant state increase the risk of developing HG. Conversely, women with β-thalassaemia, a condition in which GDF15 levels are chronically high5, report very low levels of nausea and vomiting of pregnancy. In mice, the acute food intake response to a bolus of GDF15 is influenced bi-directionally by prior levels of circulating GDF15 in a manner suggesting that this system is susceptible to desensitization. Our findings support a putative causal role for fetally derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by prepregnancy exposure to the hormone, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.

A feasibility and safety study of afamelanotide in acute stroke patients - an open label, proof of concept, phase iia clinical trial

BACKGROUND

Neuroprotective agents have the potential to improve the outcomes of revascularisation therapies in acute ischemic stroke patients (AIS) and in those unable to receive revascularisation. Afamelanotide, a synthetic α-melanocyte stimulating hormone analogue, is a potential novel neuroprotective agent. We set out to assess the feasibility and safety of afamelanotide for the first time in AIS patients.

METHODS

AIS patients within 24 h of onset, with perfusion abnormality on imaging (Tmax) and otherwise ineligible for revascularisation therapies were enrolled. Afamelanotide 16 mg implants were administered subcutaneously on Day 0 (D0, day of recruitment), D1 and repeated on D7 and D8, if not well recovered. Treatment emergent adverse events (TEAEs) and neurological assessments were recorded regularly up to D42. Magnetic resonance imaging (MRI) with FLAIR sequences were also performed on D3 and D9.

RESULTS

Six patients (5 women, median age 81, median NIHSS 6) were recruited. Two patients received 4 doses and four patients received 2. One patient (who received 2 doses), suffered a fatal recurrent stroke on D9 due to a known complete acute internal carotid artery occlusion, assessed as unrelated to the study drug. There were no other local or major systemic TEAEs recorded. In all surviving patients, the median NIHSS improved from 6 to 2 on D7. The median Tmax volume on D0 was 23 mL which was reduced to a FLAIR volume of 10 mL on D3 and 4 mL on D9.

CONCLUSIONS

Afamelanotide was well tolerated and safe in our small sample of AIS patients. It also appears to be associated with good recovery and radiological improvement of salvageable tissue which needs to be tested in randomized studies.

CLINICALTRIALS

GOV IDENTIFIER

NCT04962503, First posted 15/07/2021.

Fetally-encoded GDF15 and maternal GDF15 sensitivity are major determinants of nausea and vomiting in human pregnancy

Human pregnancy is frequently accompanied by nausea and vomiting that may become severe and life-threatening, as in hyperemesis gravidarum (HG), the cause of which is unknown. Growth Differentiation Factor-15 (GDF15), a hormone known to act on the hindbrain to cause emesis, is highly expressed in the placenta and its levels in maternal blood rise rapidly in pregnancy. Variants in the maternal GDF15 gene are associated with HG. Here we report that fetal production of GDF15, and maternal sensitivity to it, both contribute substantially to the risk of HG. We found that the great majority of GDF15 in maternal circulation is derived from the feto-placental unit and that higher GDF15 levels in maternal blood are associated with vomiting and are further elevated in patients with HG. Conversely, we found that lower levels of GDF15 in the non-pregnant state predispose women to HG. A rare C211G variant in GDF15 which strongly predisposes mothers to HG, particularly when the fetus is wild-type, was found to markedly impair cellular secretion of GDF15 and associate with low circulating levels of GDF15 in the non-pregnant state. Consistent with this, two common GDF15 haplotypes which predispose to HG were associated with lower circulating levels outside pregnancy. The administration of a long-acting form of GDF15 to wild-type mice markedly reduced subsequent responses to an acute dose, establishing that desensitisation is a feature of this system. GDF15 levels are known to be highly and chronically elevated in patients with beta thalassemia. In women with this disorder, reports of symptoms of nausea or vomiting in pregnancy were strikingly diminished. Our findings support a causal role for fetal derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by pre-pregnancy exposure to GDF15, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.

The Brain Tumor Segmentation (BraTS-METS) Challenge 2023: Brain Metastasis Segmentation on Pre-treatment MRI

Clinical monitoring of metastatic disease to the brain can be a laborious and timeconsuming process, especially in cases involving multiple metastases when the assessment is performed manually. The Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) guideline, which utilizes the unidimensional longest diameter, is commonly used in clinical and research settings to evaluate response to therapy in patients with brain metastases. However, accurate volumetric assessment of the lesion and surrounding peri-lesional edema holds significant importance in clinical decision-making and can greatly enhance outcome prediction. The unique challenge in performing segmentations of brain metastases lies in their common occurrence as small lesions. Detection and segmentation of lesions that are smaller than 10 mm in size has not demonstrated high accuracy in prior publications. The brain metastases challenge sets itself apart from previously conducted MICCAI challenges on glioma segmentation due to the significant variability in lesion size. Unlike gliomas, which tend to be larger on presentation scans, brain metastases exhibit a wide range of sizes and tend to include small lesions. We hope that the BraTS-METS dataset and challenge will advance the field of automated brain metastasis detection and segmentation.

Rare Presentation of Acute Myeloid Leukemia With TP53 Mutation and Dermatologic Manifestations

Acute myeloid leukemia (AML) is a complex and aggressive malignancy that occurs due to genetic mutations and subsequent stem cell overproduction. We report a case of a patient with AML and a highly fatal, uncommon TP53 mutation who developed dermatologic manifestations. This report serves to highlight the importance of dermatologic findings in underlying leukemia and educate healthcare providers on the diagnosis and treatment of a rare TP53 mutation in AML.

Coaxial Access for Microcatheter Stabilization During Aneurysm Coiling: 2-Dimensional Operative Video

Coaxial support is a fundamental technique utilized by neurointerventionalists to optimize distal catheter control within the intracranial circulation. Here we present a 41-yr-old woman with a previously coiled ruptured anterior communicating artery aneurysm with progressive recurrence harboring tortuous internal carotid anatomy to demonstrate the utility of coaxial support. Raymond-Roy classification of initial aneurysm coiling of class 1 resulted as class 3b over the 21 mo from initial treatment.1 The patient consented to stent-assisted coiling for retreatment of this aneurysm. Coaxial support was advanced as distally as possible in the proximal vasculature to improve catheter control, reducing dead space within which the microcatheter could move, decreasing angulations within proximal vasculature, limiting the movement of the native vessels, and providing a surface of lower friction than the endothelium. As the risk of recurrent subarachnoid hemorrhage in previously treated coiled aneurysms approaches 3%, retreatment occurs in 16.4% within 6 yr2 and in 17.4% of patients within 10 yr.3 Rerupture is slightly higher in patients who underwent coiling vs clipping, with the rerupture risk inversely proportional to the degree of aneurysm occlusion,4 further substantiating that coaxial support provides technical advantage in selected patients where additional microcatheter control is necessary for optimal occlusion. Pitfalls of this technique include vasospasm and vascular injury, which can be ameliorated by pretreatment of the circulation with vasodilators to prevent catheter-induced vasospasm. This case and model demonstration illustrates the technique of coaxial access in the stent-assisted coiling of a recurrent anterior communicating artery aneurysm and identification and management of catheter-induced vasospasm.

Optimizing the Definitions of Stroke, Transient Ischemic Attack, and Infarction for Research and Application in Clinical Practice

BACKGROUND AND PURPOSE

Until now, stroke and transient ischemic attack (TIA) have been clinically based terms which describe the presence and duration of characteristic neurological deficits attributable to intrinsic disorders of particular arteries supplying the brain, retina, or (sometimes) the spinal cord. Further, infarction has been pathologically defined as death of neural tissue due to reduced blood supply. Recently, it has been proposed we shift to definitions of stroke and TIA determined by neuroimaging results alone and that neuroimaging findings be equated with infarction.

METHODS

We examined the scientific validity and clinical implications of these proposals using the existing published literature and our own experience in research and clinical practice.

RESULTS

We found that the proposals to change to imaging-dominant definitions, as published, are ambiguous and inconsistent. Therefore, they cannot provide the standardization required in research or its application in clinical practice. Further, we found that the proposals are scientifically incorrect because neuroimaging findings do not always correlate with the clinical status or the presence of infarction. In addition, we found that attempts to use the proposals are disrupting research, are otherwise clinically unhelpful and do not solve the problems they were proposed to solve.

CONCLUSION

We advise that the proposals must not be accepted. In particular, we explain why the clinical focus of the definitions of stroke and TIA should be retained with continued sub-classification of these syndromes depending neuroimaging results (with or without other information) and that infarction should remain a pathological term. We outline ways the established clinically based definitions of stroke and TIA, and use of them, may be improved to encourage better patient outcomes in the modern era.

Bing-Neel syndrome - Bilateral cavernous sinus lymphoma causing visual failure

We report the case of a 68-year-old male with right eye vision loss secondary to a compressive optic neuropathy from Waldenstrom macroglobulinaemia relapse in both cavernous sinuses. Central nervous system involvement is extremely uncommon in lymphoplasmacytic lymphoma. Known as Bing-Neel syndrome, this has not been previously reported to present simultaneously in bilateral cavernous sinuses. We discuss the pathophysiology, diagnostic and neuroradiological features of Bing-Neel syndrome. In this case, there was marked clinical and radiological response to chemotherapy. As outcomes following treatment for Waldenstrom macroglobulinaemia improve, greater awareness of its less common manifestations becomes important. Neurosurgical intervention may be indicated to obtain histological diagnosis or decompress critical structures.

Landau-Zener-Stückelberg Interferometry in Quantum Dots with Fast Rise Times: Evidence for Coherent Phonon Driving

Manipulating qubits via electrical pulses in a piezoelectric material such as GaAs can be expected to generate incidental acoustic phonons. In this Letter we determine theoretically and experimentally the consequences of these phonons for semiconductor spin qubits using Landau-Zener-Stückelberg interferometry. Theoretical calculations predict that phonons in the presence of the spin-orbit interaction produce both phonon-Rabi fringes and accelerated evolution at the singlet-triplet anticrossing. Observed features confirm the influence of these mechanisms. Additionally, evidence is found that the pulsed gates themselves act as phonon cavities increasing the influence of phonons under specific resonant conditions.

Treating and Reducing Anxiety and Pain in the Paediatric Emergency Department (The Trapped 2 Survey): Time for Action – A Pediatric Emergency Research Canada (Perc) Project

BACKGROUND: Multiples barriers to appropriate analgesia provision are reported in the paediatric emergency department (PED), including limited accessibility to effective strategies.

OBJECTIVES: To evaluate the improvement in the accessibility of pain and anxiety management strategies in PEDs in Canada, after the creation of a national pediatric pain quality improvement collaborative, through Pediatric Emergency Research Canada.

DESIGN/METHODS: In 2013, the TRAPPED 1 survey was administered across Canadian PEDs, in order to evaluate the resources in place for pain and anxiety management. Subsequent to the TRAPPED 1, a pain Quality Improvement Collaborative was created to stimulate the implementation of new pain and anxiety management strategies through the sharing of information between PEDs. The TRAPPED 2 survey involved a cross sectional survey similar to TRAPPED 1, after a two year interval. Its main focus was to evaluate the improvement in the accessibility of specific, preferred strategies reported by each centre, after participating in this collaborative between December 2014 to November 2015, and then working to implement change within their own PEDs.

RESULTS: All 15/15 Canadian PEDs responded to TRAPPED 1 in 2013. In 2014, 11/15 agreed to participate in the national pain Quality Improvement Collaborative, with a goal of introducing new pain and anxiety management strategies within their own PEDs. An in-person meeting, email communication, and telephone meetings were employed for information sharing regarding experiences/challenges within each of the participating centres. Newly introduced strategies included education, distraction, nurse-initiated protocols, and policies/education to encourage the use of intranasal (IN) medications. 11/11 centres have responded to the interim follow up surveys in 2015. At the end of the project (Fall 2105), 15/15 Canadian PEDs agreed to complete the final TRAPPED 2 survey. When comparing the results of 2015 with 2013, an increased number of PEDs used face-based pain scales (14/15 vs 6/15) and behavioural scales (5/15 vs 1/15) for pain assessment of school-aged children and infants, respectively. Use of assessment room wall decoration for distraction increased from 7/15 to 11/15. Reminder posters for pain management at triage increased from 4/15 to 6/15. Availability of electronic distraction strategies (e.g. using tablets) increased from 4/15 to 10/15 centres. For skin-piercing procedure, nurses initiated protocols to use topical anesthetic creams and oral sucrose was available in 12/15 centres (compared to 10/15 in 2013), and 14/15 (compared to 12/15 in 2013) respectively. Availability of IN medications increased in the last two years: fentanyl 14/15 (9/15 in 2013) and midazolam in at least 10/15 (8/15 in 2013). 10/11 PEDS involved in the QI strategy reported the implementation of at least one of their strategies identified.

CONCLUSION: This study suggests that the use of a pain Quality Improvement Collaborative may improve the introduction of new strategies in multiple PEDs. It can help guide other centres when introducing new strategies to reduce pain and anxiety for children in community EDs. Future research can focus on the sustainability of the strategies, and as well the effect of the collaborative on the introduction of other pain treatment strategies.

Republished: Treatment of post-traumatic carotid–cavernous fistulas using pipeline embolization device assistance

This report describes two cases of post-traumatic, high flow carotid–cavernous fistulas that demonstrated residual shunting after initial embolization with coils and Onyx, and that were successfully closed with pipeline embolization devices. Following their combined endovascular treatments, the patients experienced clinical improvement of symptoms with durable obliteration of the fistulous communications.

Treatment of post-traumatic carotid-cavernous fistulas using pipeline embolization device assistance

This report describes two cases of post-traumatic, high flow carotid-cavernous fistulas that demonstrated residual shunting after initial embolization with coils and Onyx, and that were successfully closed with pipeline embolization devices. Following their combined endovascular treatments, the patients experienced clinical improvement of symptoms with durable obliteration of the fistulous communications.

Long-range spin transfer in triple quantum dots

Tunneling in a quantum coherent structure is not restricted to only nearest neighbors. Hopping between distant sites is possible via the virtual occupation of otherwise avoided intermediate states. Here we report the observation of long-range transitions in the transport through three quantum dots coupled in series. A single electron is delocalized between the left and right quantum dots, while the center one remains always empty. Superpositions are formed, and both charge and spin are exchanged between the outermost dots. The delocalized electron acts as a quantum bus transferring the spin state from one end to the other. Spin selection is enabled by spin correlations. The process is detected via the observation of narrow resonances which are insensitive to Pauli spin blockade.

Diffusion weighted imaging with trace diffusion weighted imaging, the apparent diffusion coefficient and exponential images in the diagnosis of spinal cord infarction

A 73-year-old man, with a history of hypertension and left supraclavicular fossa arteriovenous malformation with multiple previous uncomplicated vessel embolisation procedures, presented with acute spastic quadriparesis and urinary retention following upper limb angiography and embolisation. There was no evidence of preceding infection or neurological disease prior to the event. Cerebrospinal fluid analysis was unremarkable. MRI of the cervical spine with a 1.5 Tesla magnet performed 13 hours from symptom onset revealed bilateral paramedian intramedullary T2-weighted signal change without gadolinium enhancement limited to the grey matter with corresponding diffusion restriction extending from C5-6 down to the mid-T1. The diagnosis of cervical spinal cord infarction (SCI) was made and the patient was given regular aspirin and atorvastatin. On follow-up at 3 months, there was modest improvement with respect to his quadriparesis and was walking unaided. An extensive literature review on the role of MRI in SCI is discussed.

Bipolar spin blockade and coherent state superpositions in a triple quantum dot

Spin qubits based on interacting spins in double quantum dots have been demonstrated successfully. Readout of the qubit state involves a conversion of spin to charge information, which is universally achieved by taking advantage of a spin blockade phenomenon resulting from Pauli's exclusion principle. The archetypal spin blockade transport signature in double quantum dots takes the form of a rectified current. At present, more complex spin qubit circuits including triple quantum dots are being developed. Here we show, both experimentally and theoretically, that in a linear triple quantum dot circuit the spin blockade becomes bipolar with current strongly suppressed in both bias directions and also that a new quantum coherent mechanism becomes relevant. In this mechanism, charge is transferred non-intuitively via coherent states from one end of the linear triple dot circuit to the other, without involving the centre site. Our results have implications for future complex nanospintronic circuits.

The pentacyclic triterpenoids in herbal medicines and their pharmacological activities in diabetes and diabetic complications

Pentacyclic triterpenoids including the oleanane, ursane and lupane groups are widely distributed in many medicinal plants, such as Glycyrrhiza species, Gymnema species, Centella asiatica, Camellia sinensis, Crataegus species and Olea europaea, which are commonly used in traditional medicine for the treatment of diabetes and diabetic complications. A large number of bioactive pentacyclic triterpenoids, such as oleanolic acid, glycyrrhizin, glycyrrhetinic acid, ursolic acid, betulin, betulinic acid and lupeol have shown multiple biological activities with apparent effects on glucose absorption, glucose uptake, insulin secretion, diabetic vascular dysfunction, retinopathy and nephropathy. The versatility of the pentacyclic triterpenes provides a promising approach for diabetes management.

Quantum interference between three two-spin states in a double quantum dot

Qubits based on the singlet (S) and the triplet (T(0), T(+)) states in double quantum dots have been demonstrated in separate experiments. It has been recently proposed theoretically that under certain conditions a quantum interference could occur from the interplay between these two qubit species. Here we report experiments and modeling that confirm these theoretical predictions and identify the conditions under which this interference occurs. Density matrix calculations show that the interference pattern manifests primarily via the occupation of the common singlet state. The S/T(0) qubit is found to have a much longer coherence time as compared to the S/T(+) qubit.

Aspirin for the prevention of cognitive decline in the elderly: rationale and design of a neuro-vascular imaging study (ENVIS-ion)

BACKGROUND

This paper describes the rationale and design of the ENVIS-ion Study, which aims to determine whether low-dose aspirin reduces the development of white matter hyper-intense (WMH) lesions and silent brain infarction (SBI). Additional aims include determining whether a) changes in retinal vascular imaging (RVI) parameters parallel changes in brain magnetic resonance imaging (MRI); b) changes in RVI parameters are observed with aspirin therapy; c) baseline cognitive function correlates with MRI and RVI parameters; d) changes in cognitive function correlate with changes in brain MRI and RVI and e) whether factors such as age, gender or blood pressure influence the above associations.

METHODS/DESIGN

Double-blind, placebo-controlled trial of three years duration set in two Australian academic medical centre outpatient clinics. This study will enrol 600 adults aged 70 years and over with normal cognitive function and without overt cardiovascular disease. Subjects will undergo cognitive testing, brain MRI and RVI at baseline and after 3 years of study treatment. All subjects will be recruited from a 19,000-patient clinical outcome trial conducted in Australia and the United States that will evaluate the effects of aspirin in maintaining disability-free longevity over 5 years. The intervention will be aspirin 100 mg daily versus matching placebo, randomized on a 1:1 basis.

DISCUSSION

This study will improve understanding of the mechanisms at the level of brain and vascular structure that underlie the effects of aspirin on cognitive function. Given the limited access and high cost of MRI, RVI may prove useful as a tool for the identification of individuals at high risk for the development of cerebrovascular disease and cognitive decline.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01038583.

The Virtual Family--development of surface-based anatomical models of two adults and two children for dosimetric simulations

The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers. More than 80 different tissue types were distinguished during the segmentation. To improve the accuracy and the effectiveness of the segmentation, a novel semi-automated tool was used to analyze and segment the data. All tissues and organs were reconstructed as three-dimensional (3D) unstructured triangulated surface objects, yielding high precision images of individual features of the body. This greatly enhances the meshing flexibility and the accuracy with respect to thin tissue layers and small organs in comparison with the traditional voxel-based representation of anatomical models. Conformal computational techniques were also applied. The techniques and tools developed in this study can be used to more effectively develop future models and further improve the accuracy of the models for various applications. For research purposes, the four models are provided for free to the scientific community.

The Virtual Family--development of surface-based anatomical models of two adults and two children for dosimetric simulations

The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers. More than 80 different tissue types were distinguished during the segmentation. To improve the accuracy and the effectiveness of the segmentation, a novel semi-automated tool was used to analyze and segment the data. All tissues and organs were reconstructed as three-dimensional (3D) unstructured triangulated surface objects, yielding high precision images of individual features of the body. This greatly enhances the meshing flexibility and the accuracy with respect to thin tissue layers and small organs in comparison with the traditional voxel-based representation of anatomical models. Conformal computational techniques were also applied. The techniques and tools developed in this study can be used to more effectively develop future models and further improve the accuracy of the models for various applications. For research purposes, the four models are provided for free to the scientific community.

The Virtual Family--development of surface-based anatomical models of two adults and two children for dosimetric simulations

The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers. More than 80 different tissue types were distinguished during the segmentation. To improve the accuracy and the effectiveness of the segmentation, a novel semi-automated tool was used to analyze and segment the data. All tissues and organs were reconstructed as three-dimensional (3D) unstructured triangulated surface objects, yielding high precision images of individual features of the body. This greatly enhances the meshing flexibility and the accuracy with respect to thin tissue layers and small organs in comparison with the traditional voxel-based representation of anatomical models. Conformal computational techniques were also applied. The techniques and tools developed in this study can be used to more effectively develop future models and further improve the accuracy of the models for various applications. For research purposes, the four models are provided for free to the scientific community.

Pancreatic beta cell function persists in many patients with chronic type 1 diabetes, but is not dramatically improved by prolonged immunosuppression and euglycaemia from a beta cell allograft

AIMS/HYPOTHESIS

We measured serum C-peptide (at least 0.167 nmol/l) in 54 of 141 (38%) patients with chronic type 1 diabetes and sought factors that might differentiate those with detectable C-peptide from those without it. Finding no differences, and in view of the persistent anti-beta cell autoimmunity in such patients, we speculated that the immunosuppression (to weaken autoimmune attack) and euglycaemia accompanying transplant-based treatments of type 1 diabetes might promote recovery of native pancreatic beta cell function.

METHODS

We performed arginine stimulation tests in three islet transplant and four whole-pancreas transplant recipients, and measured stimulated C-peptide in select venous sampling sites. On the basis of each sampling site's C-peptide concentration and kinetics, we differentiated insulin secreted from the individual's native pancreatic beta cells and that secreted from allografted beta cells.

RESULTS

Selective venous sampling demonstrated that despite long-standing type 1 diabetes, all seven beta cell allograft recipients displayed evidence that their native pancreas secreted C-peptide. Yet even if chronic immunosuppression coupled with near normal glycaemia did improve native pancreatic C-peptide production, the magnitude of the effect was quite small.

CONCLUSIONS/INTERPRETATION

Some native pancreatic beta cell function persists even years after disease onset in most type 1 diabetic patients. However, if prolonged euglycaemia plus anti-rejection immunosuppressive therapy improves native pancreatic insulin production, the effect in our participants was small. We may have underestimated pancreatic regenerative capacity by studying only a limited number of participants or by creating conditions (e.g. high circulating insulin concentrations or immunosuppressive agents toxic to beta cells) that impair beta cell function.

Localization of insulinomas to regions of the pancreas by intraarterial calcium stimulation: the NIH experience

CONTEXT

Selective intraarterial calcium injection of the major pancreatic arteries with hepatic venous sampling [calcium arterial stimulation (CaStim)] has been used as a localizing tool for insulinomas at the National Institutes of Health (NIH) since 1989. The accuracy of this technique for localizing insulinomas was reported for all cases until 1996.

OBJECTIVES

The aim of the study was to assess the accuracy and track record of the CaStim over time and in the context of evolving technology and to review issues related to result interpretation and procedure complications. CaStim was the only invasive preoperative localization modality used at our center. Endoscopic ultrasound (US) was not studied.

DESIGN AND SETTING

We conducted a retrospective case review at a referral center.

PATIENTS

Twenty-nine women and 16 men (mean age, 47 yr; range, 13-78) were diagnosed with an insulinoma from 1996-2008.

INTERVENTION

A supervised fast was conducted to confirm the diagnosis of insulinoma. US, computed tomography (CT), magnetic resonance imaging (MRI), and CaStim were used as preoperative localization studies. Localization predicted by each preoperative test was compared to surgical localization for accuracy.

MAIN OUTCOME

We measured the accuracy of US, CT, MRI, and CaStim for localization of insulinomas preoperatively.

RESULTS

All 45 patients had surgically proven insulinomas. Thirty-eight of 45 (84%) localized to the correct anatomical region by CaStim. In five of 45 (11%) patients, the CaStim was falsely negative. Two of 45 (4%) had false-positive localizations.

CONCLUSION

The CaStim has remained vastly superior to abdominal US, CT, or MRI over time as a preoperative localizing tool for insulinomas. The utility of the CaStim for this purpose and in this setting is thus validated.

40. The evolution of prosthetics

Throughout history, prosthetic limbs have undergone significant changes in design and function. For example, an ancient bronze and iron prosthesis with a wooden core, discovered in Italy and dated back to 300 BC, has evolved into a modern shock-absorbing multi-axis prosthetic foot for walking on uneven ground. Recent advances in “neuro-controlled” prosthetics with microprocessor controllers further allow their users to produce smooth, multi-joint movements, simulating “real limbs”. With an increase in government funding focusing on researches in independent mobility, it is expected that new designs will improve immensely the quality of life of amputees. Are we approaching closer to the “ideal prosthetic limb”? The objective of this paper is to examine the evolution of various prosthetic designs and to re-apply some of the old concepts into new designs. The method used is mainly literature review. Results/conclusion: N/A. Wetz H, Gisbertz D. History of artificial limbs for the leg. Orthopade 2000; 29(12):1018-32. Pascual G. Amputations, walking and prosthesis development. An R Acad Nac Med (Madr) 2003; 120(3):593-607. Cottrell-Ikerd V, Ikerd F, Jenkins DW. The Syme’s amputation: a correlation of surgical technique and prosthetic management with an historical perspective 1994; 33(4):355-64.

Intermittent hepatic vein balloon occlusion during radiofrequency ablation in the liver

The purpose of the study was to assess the feasibility of intermittent hepatic vein balloon occlusion during percutaneous radiofrequency (RF) ablation. Eight non-anticoagulated patients who had primary (n = 2) and metastatic (n = 6) liver tumors with a mean diameter of 4.2 cm (range 2.4-6.5 cm) were treated, resulting in a mean ablation diameter of 6.3 cm (range 4.3-9.3 cm). Six of 9 (67%) of the balloon-occluded hepatic veins were patent. No clinical sequelae of thrombosis were noted. Mean length of follow-up with CT and/or MRI was 12 months. Local tumor control was achieved in 5 of 8 patients. Intermittent hepatic vein balloon occlusion could potentially be a low-risk adjunctive maneuver for thermal ablation therapy in the treatment of large tumors and tumors adjacent to large vessels.

Thermal protection with 5% dextrose solution blanket during radiofrequency ablation

A serious complication for any thermal radiofrequency ablation is thermal injury to adjacent structures, particularly the bowel, which can result in additional major surgery or death. Several methods using air, gas, fluid, or thermometry to protect adjacent structures from thermal injury have been reported. In the cases presented in this report, 5% dextrose water (D5W) was instilled to prevent injury to the bowel and diaphragm during radiofrequency ablation. Creating an Insulating envelope or moving organs with D5W might reduce risk for complications such as bowel perforation.

Detection of K-complexes in sleep EEG using CD-HMM

In the current paper a new approach for K-complex detection using a continuous density hidden Markov model (CD-HMM) is presented. The system performance was evaluated in two manners. First using three seconds long segments of K-complexes and of background EEG (classification problem). Second using a whole night record and detecting the K complexes (detection problem). The fist test achieved an equal error rate of 7%. In the second test the system performance was compared to four trained scores that scored the signal independently. The performance of the algorithm was within the variance of the human scorers.

Stability diagram of a few-electron triple dot

Individual and coupled quantum dots containing one or two electrons have been realized and are regarded as components for future quantum information circuits. In this Letter we map out experimentally the stability diagram of the few-electron triple dot system, the electron configuration map as a function of the external tuning parameters, and reveal experimentally for the first time the existence of quadruple points, a signature of the three dots being in resonance. In the vicinity of these quadruple points we observe a duplication of charge transfer transitions related to charge and spin reconfigurations triggered by changes in the total electron occupation number. The experimental results are largely reproduced by equivalent circuit analysis and Hubbard models. Our results are relevant for future quantum mechanical engineering applications within both quantum information and quantum cellular automata architectures.

Radiofrequency ablation of cancer

Radiofrequency ablation (RFA) has been used for over 18 years for treatment of nerve-related chronic pain and cardiac arrhythmias. In the last 10 years, technical developments have increased ablation volumes in a controllable, versatile, and relatively inexpensive manner. The host of clinical applications for RFA have similarly expanded. Current RFA equipment, techniques, applications, results, complications, and research avenues for local tumor ablation are summarized.

Nasal septum buttons: symptom scores and satisfaction

Patients with symptomatic septal perforations require treatment, with many surgeons advocating primary treatment with an obturator if conservative measures fail. Twenty nasal Button Outcome Questionnaires were sent to patients who had undergone insertion of a septal button between 1990 and 2000 in our unit. Fourteen questinnaires were returned. This study reveals that despite a reduction in symptom score in nine patients, septal buttons are poorly tolerated by patients with only 45 per cent of obturators ultimately being in situ. In view of these findings, patients are now offered a choice between primary surgical and mechanical closure in our unit.

Microsurgical anatomy of the superior and recurrent laryngeal nerves

OBJECTIVE

To study the microsurgical anatomy of the superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) with respect to anatomic landmarks, and to identify their vascular supplies.

METHODS

The microsurgical anatomy of the anterior neck, the course of the right and left SLN and RLN and their variations were studied in 21 cadavers. Fresh cadavers were perfused with colored silicon dye to investigate the microvasculature in detail.

RESULTS

SLN originates from the inferior vagal ganglion at the C2 level and descends medially toward the thyrohyoid membrane. It branches into an external and an internal branch deep to the internal carotid artery at the C3 level. The external branch, along with the cricothyroid artery, descends deep to the superior thyroid artery toward the cricothyroid muscle. Accompanied by the superior laryngeal artery, the internal branch passes deep to the loop of the superior thyroid artery and pierces the thyrohyoid membrane. Both nerves reside in the fascia covering longus colli muscles and are supplied by their accompanying arteries. The loop of RLN is found at the T1-T3 level on the right, and more caudally at the T3-T6 level on the left, entering the larynx between C5-C7 levels on both sides. RLN receives arterial supply from the esophageal and tracheal branches of the inferior thyroid artery proximally, and by the inferior laryngeal artery distally.

CONCLUSION

Incidental intraoperative injury to the SLN and RLN potentially could be avoided by understanding the detailed course of each nerve with respect to the surrounding anatomic landmarks and by recognizing their blood supplies.

Case report: inappropriate use of percutaneous drainage in the management of pancreatic necrosis

We describe three cases of severe necrotizing pancreatitis, with Apache II scores of 11, 17 and 22, respectively. There was no significant pancreatic parenchymal perfusion in any of the three patients on contrast-enhanced computed tomography. All three patients were primarily treated with percutaneous drains and all three subsequently required open laparotomies. We do not recommend percutaneous drainage as a definitive therapy for severe necrotizing pancreatitis.