Vitamin B5 supports MYC oncogenic metabolism and tumor progression in breast cancer.

Tumors are intrinsically heterogeneous and it is well established that this directs their evolution, hinders their classification and frustrates therapy1-3. Consequently, spatially resolved omics-level analyses are gaining traction4-9. Despite considerable therapeutic interest, tumor metabolism has been lagging behind this development and there is a paucity of data regarding its spatial organization. To address this shortcoming, we set out to study the local metabolic effects of the oncogene c-MYC, a pleiotropic transcription factor that accumulates with tumor progression and influences metabolism10,11. Through correlative mass spectrometry imaging, we show that pantothenic acid (vitamin B5) associates with MYC-high areas within both human and murine mammary tumors, where its conversion to coenzyme A fuels Krebs cycle activity. Mechanistically, we show that this is accomplished by MYC-mediated upregulation of its multivitamin transporter SLC5A6. Notably, we show that SLC5A6 over-expression alone can induce increased cell growth and a shift toward biosynthesis, whereas conversely, dietary restriction of pantothenic acid leads to a reversal of many MYC-mediated metabolic changes and results in hampered tumor growth. Our work thus establishes the availability of vitamins and cofactors as a potential bottleneck in tumor progression, which can be exploited therapeutically. Overall, we show that a spatial understanding of local metabolism facilitates the identification of clinically relevant, tractable metabolic targets.

Determining the Level and Location of Functional Groups on Few-Layer Graphene and Their Effect on the Mechanical Properties of Nanocomposites.

Graphene is a highly desirable material for a variety of applications; in the case of nanocomposites, it can be functionalized and added as a nanofiller to alter the ultimate product properties, such as tensile strength. However, often the material properties of the functionalized graphene and the location of any chemical species, attached via different functionalization processes, are not known. Thus, it is not necessarily understood why improvements in product performance are achieved, which hinders the rate of product development. Here, a commercially available powder containing few-layer graphene (FLG) flakes is characterized before and after plasma or chemical functionalization with either nitrogen or oxygen species. A range of measurement techniques, including tip-enhanced Raman spectroscopy (TERS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and NanoSIMS, were used to examine the physical and chemical changes in the FLG material at both the micro- and nanoscale. This is the first reported TERS imaging of commercially available FLG flakes of submicron lateral size, revealing the location of the defects (edge versus basal plane) and variations in the level of functionalization. Graphene-polymer composites were then produced, and the dispersion of the graphitic material in the matrix was visualized using ToF-SIMS. Finally, mechanical testing of the composites demonstrated that the final product performance could be enhanced but differed depending on the properties of the original graphitic material.

Microdistribution and quantification of the boron neutron capture therapy drug BPA in primary cell cultures of human glioblastoma tumour by NanoSIMS.

The ability of secondary ion mass spectrometry (SIMS) to provide high sensitivity imaging of elements and small-medium mass molecules in biological tissues and cells, makes it a very powerful tool for drug distribution studies. Here we report on the application of a high-resolution dynamic SIMS instrument for the quantification and localisation of therapeutic levels of the BNCT agent l-para-(dihydroxyboryl)-phenylalanine (BPA) in primary cell cultures from human patients exhibiting glioblastoma multiform tumours. Boron uptake and distribution was determined quantitatively as a function of cell-sampling location and different treatment regimes. Importantly, BPA was found to accumulate in cancer cells invading the 'brain around tumour' tissue in addition to the main tumour site. Pre-treatment of samples with l-tyrosine was found not to increase the uptake of BPA, nor change the intracellular drug distribution. In cultured cells from the tumour core and brain around tumour, with and without l-tyrosine pre-treatment, normalised boron-related signals were higher from cell nuclei than from cytoplasm. An efflux treatment was found to reduce BPA levels, but at a rate slower than the original uptake, and did not affect the intracellular drug distribution. To the best of our knowledge, these data represent the first published study of BPA uptake and l-amino acid pre-treatment in cultured primary human cells using dynamic SIMS, and the most detailed, subcellular distribution study of a BNCT agent in any cellular system.

Leg ischaemia management collaboration (LIMb): study protocol for a prospective cohort study at a single UK centre.

INTRODUCTION: Severe limb ischaemia (SLI) is the end stage of peripheral arterial occlusive disease where the viability of the limb is threatened. Around 25% of patients with SLI will ultimately require a major lower limb amputation, which has a substantial adverse impact on quality of life. A newly established rapid-access vascular limb salvage clinic and modern revascularisation techniques may reduce amputation rate. The aim of this study was to investigate the 12-month amputation rate in a contemporary cohort of patients and compare this to a historical cohort. Secondary aims are to investigate the use of frailty and cognitive assessments, and cardiac MRI in risk-stratifying patients with SLI undergoing intervention and establish a biobank for future biomarker analyses. METHODS AND ANALYSIS: This single-centre prospective cohort study will recruit patients aged 18-110 years presenting with SLI. Those undergoing intervention will be eligible to undergo additional venepuncture (for biomarker analysis) and/or cardiac MRI. Those aged ≥65 years and undergoing intervention will also be eligible to undergo additional frailty and cognitive assessments. Follow-up will be at 12 and 24 months and subsequently via data linkage with NHS Digital to 10 years postrecruitment. Those undergoing cardiac MRI and/or frailty assessments will receive additional follow-up during the first 12 months to investigate for perioperative myocardial infarction and frailty-related outcomes, respectively. A sample size of 420 patients will be required to detect a 10% reduction in amputation rate in comparison to a similar sized historical cohort, with 90% power and 5% type I error rate. Statistical analysis of this comparison will be by adjusted and unadjusted logistic regression analyses. ETHICS AND DISSEMINATION: Ethical approval for this study has been granted by the UK National Research Ethics Service (19/LO/0132). Results will be disseminated to participants via scientific meetings, peer-reviewed medical journals and social media. TRIAL REGISTRATION NUMBER: NCT04027244.

Carotid artery aneurysm: last among equals.

A 66-year-old man presented initially with a swelling in the left side of the neck, which was confirmed to be a carotid artery aneurysm on ultrasonography. He was subsequently admitted reporting intermittent episodes of visual loss in the left eye and right arm weakness. Further imaging confirmed multiple, small acute infarcts in the left cerebral hemisphere. The patient underwent open repair of the aneurysm and made an uncomplicated recovery with no persisting neurological deficit.

Transient heparin-induced platelet activation linked to generation of platelet 12-lipoxygenase. Findings from a randomised controlled trial.

Previously we demonstrated that heparin administration during carotid endarterectomy (CEA) caused a marked, but transient increase in platelet aggregation to arachidonic acid (AA) and adenosine diphosphate (ADP), despite effective platelet cyclo-oxygenase-1 (COX-1) inhibition with aspirin. Here we investigated the metabolism of AA via platelet 12-lipoxygenase (12-LOX) as a possible mediator of the observed transient aspirin resistance, and compared the effects of unfractionated (UFH) and low-molecular-weight (LMWH) heparin. A total of 43 aspirinated patients undergoing CEA were randomised in the trial to 5,000 IU UFH (n=22) or 2,500 IU LMWH (dalteparin, n=21). Platelet aggregation to AA (4x10⁻³) and ADP (3x10⁻6) was determined, and the products of the COX-1 and 12-LOX pathways; thromboxane B2 (TXB2) and 12-hydroxyeicosatretraenoic acid (12-HETE) were measured in plasma, and in material released from aggregating platelets.Aggregation to AA increased significantly (~10-fold) following heparinisation (p<0.0001), irrespective of heparin type (p=0.33). Significant, but smaller (~2-fold) increases in aggregation to ADP were also seen, which were significantly lower in the platelets of patients randomised to LMWH (p<0.0001). Plasma levels of TxB2 did not rise following heparinisation (p=0.93), but 12-HETE increased significantly in the patients' plasma, and released from platelets stimulated in vitro withADP, with both heparin types (p<0.0001). The magnitude of aggregation to ADP correlated with 12-HETE generation (p=0.03). Heparin administration during CEA generates AA that is metabolised to 12-HETE via the 12-LOX pathway, possibly explaining the phenomenon of transient heparin-induced platelet activation. LMWH has less effect on aggregation and 12-HETE generation than UFH when the platelets are stimulated with ADP.

Combined emergency abdominal aortic aneurysm repair and valve replacement in a patient with severe aortic stenosis.

Simultaneous open surgery has been advocated in the elective management of abdominal aortic aneurysm patients with significant ischemic heart disease, as staged procedures risk worsening myocardial ischemia or aortic rupture, depending on which is the first intervention. The argument for combined aneurysm and valve repair is less established. We describe the case of a 70-year-old female who while awaiting aortic valve replacement suffered rupture of an abdominal aortic aneurysm. The patient was successfully managed with emergency combined open abdominal aortic aneurysm repair and open aortic valve replacement. We would advocate that such a strategy be considered as a salvage technique in similarly difficult management dilemmas.

Periaortic inflammation after endovascular aneurysm repair.

BACKGROUND: The periaortitis seen with inflammatory abdominal aortic aneurysms usually resolves after repair by both open and endovascular techniques. Conversely, the de novo development of retroperitoneal fibrosis after endovascular aneurysm repair (EVAR) has also been rarely described, and we present a case and also review the literature. METHODS AND RESULTS: A 63-year-old man underwent EVAR for an asymptomatic, noninflammatory abdominal aortic aneurysm, presenting 9 months subsequently with left loin pain, raised inflammatory markers, and radiological evidence of periaortic inflammation causing significant left ureteric obstruction. Ureteric stenting resolved the hydronephrosis, and the periaortitis improved with combination of steroid and tamoxifen therapy. CONCLUSION: Periaortitis causing renal impairment after EVAR is a rare complication. Prompt recognition and ureteric stenting helps to prevent long-term renal damage. Steroid and tamoxifen therapy is recommended to treat and avoid recurrence of periaortitis.

Bile duct "clip-stones"--why a stitch in time could save nine.

A 32 year old female patient underwent laparoscopic cholecystectomy and in the post-operative phase was investigated after developing obstructive jaundice. ERCP revealed a stenosis at the junction of the cystic and common hepatic ducts and this was seen to be directly adjacent to the clips which had been used to ligate the cystic duct. The stricture was easily dilated with a balloon and all her symptoms improved and her liver function tests returned to normal. Eight years later she represented with a mid-common bile duct calculus. An ERCP was performed but the stone could not be dislodged or retrieved and when removed subsequently at open exploration it was found to have precipitated around two metal clips, which had migrated into the lumen of the common bile duct. We propose that the risk of this rare, yet previously reported complication, could be reduced by heeding the longstanding recommendation that only absorbable material be used in biliary surgery, and particularly when there is a short cystic duct.

"Masson's pseudoangiosarcoma" in a popliteal aneurysm: tumor or thrombus? Cause or effect?

A 44-year-old male presented to our vascular surgery unit with a partially thrombosed 22 mm popliteal aneurysm giving rise to progressive distal ischemia. Microscopy of embolus retrieved from the posterior tibial artery at bypass surgery revealed the unexpected finding of intravascular papillary endothelial hyperplasia (Masson's pseudoangiosarcoma).

Alcohol harm and cost at a community level: data from police and health.

INTRODUCTION: The Australian National Alcohol Strategy 2006-2009 recommends strengthening data collection at the local level, gathering information from emergency department (ED) attendees and, by integrating data sources, to develop a better understanding of alcohol- related harm. We piloted a method to estimate the number of alcohol-related presentations to ED and alcohol-related police incidents in a remote regional centre. We explore the practicality and benefits of integrating such alcohol related police and health data. SUBJECTS AND SETTING: Broken Hill Hospital is the district hospital that serves Broken Hill and surrounds in far west New South Wales, a population of approximately 20 000, over 90% of whom live in the town itself. Computerised records of all attendances are available. The Barrier police command is based in Broken Hill with 56 police. METHOD: Over two one-week periods a combination of a short patient questionnaire, nurses' assessment and concordance with Broken Hill police records were used to determine alcohol-related presentations. RESULTS: Both health and police data showed seasonal variation, with alcohol-related incidents and costs doubling in warmer weather. Altogether 32 people (5% of all 602 presentations) were recorded as having consumed alcohol prior to the event that brought them to ED. From 765 events, police attended 118 (15%) alcohol-related incidents. While the two groups were essentially independent, they were very similar demographically. The majority (68%) were males aged in their 30s who came to ED/ police notice in the late evening/early morning, mainly in the weekend. By integrating police data, routine ED data and an ED survey, a more comprehensive picture of alcohol-related harms emerged. CONCLUSION: Future research would benefit from the use of project officers in ED and in the police force, to improve compliance and data completeness. A more comprehensive local picture would also include data from other agencies dealing with alcohol. A longer study is necessary to confirm the preliminary data on seasonal variation. Key words: alcohol, emergency department, injury prevention/ early intervention, intoxication, police incidents/crime.

The value of urgent carotid surgery for crescendo transient ischemic attacks.

OBJECTIVE: This study audited operative risk in patients undergoing urgent carotid surgery for crescendo transient ischemic attacks (TIAs). METHODS: Interrogation of the vascular unit database (January 1992 to July 2004) identified 42 patients operated on urgently for crescendo TIAs, which were defined as>or=3 TIAs within the preceding 7 days. Stroke, death, and any major cardiac events were analyzed. RESULTS: Thirty-nine patients underwent conventional endarterectomy, and three underwent interposition vein bypass. Crescendo TIA patients had sustained a median of five TIAs (range, 3 to 20) in the 7 days before surgery. Three patients died or had a stroke after surgery, for a combined stroke/death rate of 7%. This compares with 2.4% in 1000 patients undergoing elective carotid endarterectomy in this unit during the same time period. The combined stroke/death/major cardiac event rate was 14% (n=6). CONCLUSIONS: The combined risk of neurologic and cardiac complications after urgent carotid surgery for crescendo TIA is higher than that expected after elective cases but is still acceptable considering the natural history of patients with unstable neurologic symptoms.

Axillomesenteric bypass: an unusual solution to a difficult problem.

A 49-year-old woman presented with acute anuric renal failure and severe hypertension. Imaging revealed occlusion of the distal thoracic and abdominal aorta. Acute hemodialysis and reduction in blood pressure precipitated an acute exacerbation of previously undiagnosed mesenteric ischemia. Repeated episodes of flash pulmonary edema and a generally parlous clinical condition precluded thoracoabdominal reconstruction. As a result, a left axillomesenteric bypass was performed as a substitute, using a 6-mm externally ringed PTFE graft. She made an uneventful recovery, and her abdominal symptoms resolved swiftly. The patient remains symptom-free 12 months postoperatively. In this rare situation, extra-anatomic bypass provided an unorthodox but less-invasive solution to a difficult surgical problem.

High-resolution quantitative imaging of mammalian and bacterial cells using stable isotope mass spectrometry.

BACKGROUND: Secondary-ion mass spectrometry (SIMS) is an important tool for investigating isotopic composition in the chemical and materials sciences, but its use in biology has been limited by technical considerations. Multi-isotope imaging mass spectrometry (MIMS), which combines a new generation of SIMS instrument with sophisticated ion optics, labeling with stable isotopes, and quantitative image-analysis software, was developed to study biological materials. RESULTS: The new instrument allows the production of mass images of high lateral resolution (down to 33 nm), as well as the counting or imaging of several isotopes simultaneously. As MIMS can distinguish between ions of very similar mass, such as 12C15N- and 13C14N-, it enables the precise and reproducible measurement of isotope ratios, and thus of the levels of enrichment in specific isotopic labels, within volumes of less than a cubic micrometer. The sensitivity of MIMS is at least 1,000 times that of 14C autoradiography. The depth resolution can be smaller than 1 nm because only a few atomic layers are needed to create an atomic mass image. We illustrate the use of MIMS to image unlabeled mammalian cultured cells and tissue sections; to analyze fatty-acid transport in adipocyte lipid droplets using 13C-oleic acid; to examine nitrogen fixation in bacteria using 15N gaseous nitrogen; to measure levels of protein renewal in the cochlea and in post-ischemic kidney cells using 15N-leucine; to study DNA and RNA co-distribution and uridine incorporation in the nucleolus using 15N-uridine and 81Br of bromodeoxyuridine or 14C-thymidine; to reveal domains in cultured endothelial cells using the native isotopes 12C, 16O, 14N and 31P; and to track a few 15N-labeled donor spleen cells in the lymph nodes of the host mouse. CONCLUSION: MIMS makes it possible for the first time to both image and quantify molecules labeled with stable or radioactive isotopes within subcellular compartments.

Endovascular abdominal aortic aneurysm repair in the presence of a kidney transplant: therapeutic considerations.

Abdominal aortic aneurysm (AAA) repair in the presence of a kidney transplant can be extremely challenging, as it carries significant risks of renal ischemia. Endovascular repair is an attractive option, as it can be performed with little or no impairment of renal arterial flow. We describe the endovascular management of a recurrent AAA in a patient with a functioning renal transplant using a custom-made aorto-uni-iliac device. We discuss the planning and the potential problems of the technique.