Distributions of easy axes and reversal processes in patterned MRAM arrays

The distribution of the easy-axes in an array of MRAM cells is a vital parameter to understand the switching and characteristics of the devices. By measuring the coercivity as a function of applied-field angle, and remaining close to the perpendicular orientation, a classic Stoner-Wohlfarth approximation has been applied to the resulting variation to determine the standard deviation, [Formula: see text], of a Gaussian distribution of the orientation of the easy-magnetisation directions. In this work we have compared MRAM arrays with nominal cells sizes of 20 nm and 60 nm and a range of free layer thicknesses. We have found that a smaller diameter cell will have a wider switching-field distribution with a standard deviation [Formula: see text]. The MRAM arrays consist of pillars produced by etching a multilayer thin film. This value of [Formula: see text] is dominated by pillar uniformity and edge effects controlling the reversal, reinforcing the need for ever-improving etch processes. This is compared to larger pillars, with distributions as low as [Formula: see text]. Furthermore we found that the distribution broadens from [Formula: see text] to [Formula: see text] with free layer thickness in larger pillars and that thinner films had a more uniform easy-axis orientation. For the 20 nm pillars the non-uniform size distribution of the pillars, with a large and unknown error in the free-layer volume, was highlighted as it was found that the activation volume for the reversal of the free layer 930 nm[Formula: see text] was larger than the nominal physical volume of the free layer. However for the 60 nm pillars, the activation volume was measured to be equal to one fifth of their physical volume. This implies that the smaller pillars effectively reverse as one entity while the larger pillars reverse via an incoherent mechanism of nucleation and propagation.

SARS-CoV-2 outbreak among staff and evacuees at Operation Allies Welcome Safe Havens

We report on five SARS-CoV-2 congregate setting outbreaks at U.S. Operation Allies Welcome Safe Havens/military facilities. Outbreak data were collected, and attack rates were calculated for various populations. Even in vaccinated populations, there was rapid spread, illustrating the importance of institutional prevention and mitigation policies in congregate settings.

The human RAP1 and GFAPɛ proteins increase γ-secretase activity in a yeast model system

Alzheimer's disease (AD) is an age-related disorder that results in progressive cognitive impairment and memory loss. Deposition of amyloid β (Aβ) peptides in senile plaques is a hallmark of AD. γ-secretase produces Aβ peptides, mostly as the soluble Aβ40 with fewer insoluble Aβ42 peptides. Rare, early-onset AD (EOAD) occurs in individuals under 60 years of age. Most EOAD cases are due to unknown genetic causes, but a subset is due to mutations in the genes encoding the amyloid precursor protein that is processed into Aβ peptides or the presenilins (PS1 and PS2) that process APP. PS1 interacts with the epsilon isoform of glial fibrillary acidic protein (GFAPɛ), a protein found in the subventricular zone of the brain. We have found that GFAPɛ interacts with the telomere protection factor RAP1 (TERF2IP). RAP1 can also interact with PS1 alone or with GFAPɛ in vitro. Our data show that the nuclear protein RAP1 has an extratelomeric role in the cytoplasm through its interactions with GFAPɛ and PS1. GFAPɛ coprecipitated with RAP1 from human cell extracts. RAP1, GFAPɛ, and PS1 all colocalized in human SH-SY5Y cells. Using a genetic model of the γ-secretase complex in Saccharomyces cerevisiae, RAP1 increased γ-secretase activity, and this was potentiated by GFAPɛ. Our studies are the first to connect RAP1 with an age-related disorder.

Leveraging metabolic modeling to identify functional metabolic alterations associated with COVID-19 disease severity

OBJECTIVE

Since the COVID-19 pandemic began in early 2020, SARS-CoV2 has claimed more than six million lives world-wide, with over 510 million cases to date. To reduce healthcare burden, we must investigate how to prevent non-acute disease from progressing to severe infection requiring hospitalization.

METHODS

To achieve this goal, we investigated metabolic signatures of both non-acute (out-patient) and severe (requiring hospitalization) COVID-19 samples by profiling the associated plasma metabolomes of 84 COVID-19 positive University of Virginia hospital patients. We utilized supervised and unsupervised machine learning and metabolic modeling approaches to identify key metabolic drivers that are predictive of COVID-19 disease severity. Using metabolic pathway enrichment analysis, we explored potential metabolic mechanisms that link these markers to disease progression.

RESULTS

Enriched metabolites associated with tryptophan in non-acute COVID-19 samples suggest mitigated innate immune system inflammatory response and immunopathology related lung damage prevention. Increased prevalence of histidine- and ketone-related metabolism in severe COVID-19 samples offers potential mechanistic insight to musculoskeletal degeneration-induced muscular weakness and host metabolism that has been hijacked by SARS-CoV2 infection to increase viral replication and invasion.

CONCLUSIONS

Our findings highlight the metabolic transition from an innate immune response coupled with inflammatory pathway inhibition in non-acute infection to rampant inflammation and associated metabolic systemic dysfunction in severe COVID-19.

Global declines in coral reef calcium carbonate production under ocean acidification and warming

Ocean warming and acidification threaten the future growth of coral reefs. This is because the calcifying coral reef taxa that construct the calcium carbonate frameworks and cement the reef together are highly sensitive to ocean warming and acidification. However, the global-scale effects of ocean warming and acidification on rates of coral reef net carbonate production remain poorly constrained despite a wealth of studies assessing their effects on the calcification of individual organisms. Here, we present global estimates of projected future changes in coral reef net carbonate production under ocean warming and acidification. We apply a meta-analysis of responses of coral reef taxa calcification and bioerosion rates to predicted changes in coral cover driven by climate change to estimate the net carbonate production rates of 183 reefs worldwide by 2050 and 2100. We forecast mean global reef net carbonate production under representative concentration pathways (RCP) 2.6, 4.5, and 8.5 will decline by 76, 149, and 156%, respectively, by 2100. While 63% of reefs are projected to continue to accrete by 2100 under RCP2.6, 94% will be eroding by 2050 under RCP8.5, and no reefs will continue to accrete at rates matching projected sea level rise under RCP4.5 or 8.5 by 2100. Projected reduced coral cover due to bleaching events predominately drives these declines rather than the direct physiological impacts of ocean warming and acidification on calcification or bioerosion. Presently degraded reefs were also more sensitive in our analysis. These findings highlight the low likelihood that the world's coral reefs will maintain their functional roles without near-term stabilization of atmospheric CO2 emissions.

Epifaunal invertebrate assemblages associated with branching Pocilloporids in Moorea, French Polynesia

Reef-building corals can harbour high abundances of diverse invertebrate epifauna. Coral characteristics and environmental conditions are important drivers of community structure of coral-associated invertebrates; however, our current understanding of drivers of epifaunal distributions is still unclear. This study tests the relative importance of the physical environment (current flow speed) and host quality (e.g., colony height, surface area, distance between branches, penetration depth among branches, and background partial mortality) in structuring epifaunal communities living within branching Pocillopora colonies on a back reef in Moorea, French Polynesia. A total of 470 individuals belonging to four phyla, 16 families and 39 genera were extracted from 36 Pocillopora spp. colonies. Decapods were the most abundant epifaunal organisms (accounting for 84% of individuals) found living in Pocillopora spp. While coral host characteristics and flow regime are very important, these parameters were not correlated with epifaunal assemblages at the time of the study. Epifaunal assemblages associated with Pocillopora spp. were consistent and minimally affected by differences in host characteristics and flow regime. The consistency in abundance and taxon richness among colonies (regardless of habitat characteristics) highlighted the importance of total habitat availability. With escalating effects of climate change and other localized disturbances, it is critical to preserve branching corals to support epifaunal communities.

Characterizations of handwashing sink activities in a single hospital medical intensive care unit

BACKGROUND

Handwashing sink drains are increasingly implicated as a potential reservoir of antibiotic-resistant bacteria in hospital outbreaks; however, usage patterns that may promote this source remain unknown.

AIM

To understand behaviours in the intensive care unit (ICU) that may facilitate establishment and nosocomial transmission of multidrug-resistant Gram negatives from a sink-trap reservoir to a patient.

METHODS

Motion-sensitive cameras captured anonymized activity paired with periodic in-person observations during a quality investigation from four ICU sinks (two patient rooms and two patient bathrooms) in a university hospital.

FINDINGS

We analysed 4810 sink videos from 60 days in patient rooms (3625) and adjoining bathrooms (1185). There was a false-positive rate of 38% (1837 out of 4810) in which the camera triggered but no sink interaction occurred. Of the 2973 videos with analysed behaviours there were 5614 observed behaviours which were assessed as: 37.4% medical care, 29.2% additional behaviours, 17.0% hand hygiene, 7.2% patient nutrition, 5.0% environmental care, 4.2% non-medical care. Handwashing was only 4% (224 out of 5614) of total behaviours. Sub-analysis of 2748 of the later videos further categorized 56 activities where a variety of nutrients, which could promote microbial growth, were disposed of in the sink.

CONCLUSION

Several non-hand hygiene activities took place regularly in ICU handwashing sinks; these may provide a mechanism for nosocomial transmission and promotion of bacterial growth in the drain. Redesigning hospital workflow and sink usage may be necessary as it becomes apparent that sink drains may be a reservoir for transmission of multidrug-resistant bacteria.

Characterization of the transient middle cerebral artery occlusion model of ischemic stroke in a HuR transgenic mouse line

This set of experiments characterizes a model of transient cerebral ischemic stroke in a transgenic (Tg) mouse line in which the glial fibrillary acidic protein (GFAP) promoter is utilized to drive expression of a human RNA-binding protein, HuR. Additionally, the effect of cerebral ischemia on the expression of endogenous Hu proteins is presented.

Patient-Specific Finite-Element Analysis of Three Intramedullary Nails for Tibiotalocalcaneal Fusion

Category:

Ankle, Hindfoot

Introduction/Purpose:

Tibiotalocalcaneal (TTC) arthrodesis is a salvage procedure for patients with severe osteoarthritis and other degenerative ankle conditions. Oftentimes, an intramedullary (IM) nail is implanted across the joints and then fixed with tibial and calcaneal screws. Maintaining compression and load sharing are both largely desired to promote fusion via primary bone healing; however, compression can be lost due to small amounts of bone resorption and IM nails are now being made from carbon-fiber epoxy to minimize stress shielding. To date, no one has been able to directly characterize or compare the specific amount of these parameters across nails in a single model. The purpose of this study is to compare influence of nail design and materials for compressive and load-sharing properties using a patient-specific finite-element model.

Methods:

A titanium nail, a pseudoelastic nickel-titanium nail, and carbon fiber-epoxy nail were investigated for (1) load sharing between the nail body and tibia under gait loading and (2) compression loss as a function of resorption in the talus. A patient- specific model of the ankle, both in geometry and material properties, was generated from a quantitative computed tomography (QCT) scan of a healthy leg. The models were segmented and meshed using SCANIP and exported into ABAQUS for finite- element analysis. Compression in the nickel-titanium nail was simulated by pre-stretching the pseudoelastic compressive element. Conversely, compression in the titanium and carbon-fiber nails were generated by giving the nail jacket an orthotropic contraction coefficient in the model. After compression was set, each nail was subjected to an applied gait load that peaked at 1121 N. Resorption was simulated using a thin compressible layer of bone in the talus and decreasing the modulus and Poisson’s ratio.

Results:

Surprisingly, the carbon-fiber nail showed similar stress shielding to the titanium nail, with 72% and 77% of the stress being transferred through the devices instead of the ankle, respectively. Even though carbon fiber-epoxy has a significantly lower modulus than titanium (75 GPa vs 110 GPa), the overall stiffness of the nails was still much greater than that of bone (~30,000 N/mm vs. ~44,000 N/mm vs. ~3,000 N/mm, respectively). The pseudoelastic nail only shielded 32% of the stress values by comparison. For the titanium and carbon-fiber nails, over 85% of the initial compression provided by the nail drops with 0.10 mm of resorption. The pseudoelastic nail maintained 90% of its initial compression after 0.10 mm of resorption.

Conclusion:

IM nail design and materials played a significant role in maintaining compression and load sharing. The pseudoelastic nail had the lowest degree of stress-shielding (32%) and maintained compression for over 0.10 mm of simulated resorption. Constant compression and the avoidance of “resorption gapping” is paramount to drive primary bone healing in joint fusions due to lack of periosteal/endosteal anatomy crossing the fusion site, thus impairing the ability for secondary bone healing (callus healing). This model allows for direct comparison between devices and can be used pre-operatively to predict patient-specific performance and help aid in device selection for TTC fusion.

Phaeochromocytoma and Paraganglioma Excision Involving the Great Vessels

Objective/background

Phaeochromocytomas and paragangliomas are vascular neuroendocrine tumours distributed between the neck and the pelvis and may be associated with catecholamine secretion. The aim of the study was to describe the complex surgical management required to excise these tumours when in close proximity to the great vessels (aorta and vena cava).

Methods

This was a retrospective case series. Patients included those undergoing surgical excision of a phaeochromocytoma or paraganglioma involving the great vessels. Data on clinical presentation; genetic mutations; tumour location; catecholamine/metanephrine secretion; surgical strategy; pre-, intra-, and post-operative course were collated.

Results

Five patients (age range 16–60 years) were identified; three had thoracic paragangliomas located under the arch of the aorta, one had an abdominal paraganglioma invading the aorta, and one had a massive phaeochromocytoma invading the inferior vena cava via the adrenal vein. Three patients had predisposing germline mutations. All patients had adrenergic blockade prior to surgery. A diverse range of complex surgical techniques were employed to excise tumours, including cardiopulmonary bypass, aortic resection, grafting and venotomy of the vena cava. Early post-operative complications were limited.

Conclusions

Excision of phaeochromocytomas and paragangliomas involving the great vessels is high risk surgery optimally undertaken within a multidisciplinary setting in a tertiary referral centre. Comprehensive radiological and biochemical assessment, meticulous pre-operative preparation and close intra- and post-operative monitoring are essential. Radiological imaging may be unable to resolve the tumour extent and anatomy pre-operatively and direct visualisation of the tumour may be the only way to clarify the surgical strategy. Pre-operative knowledge of the genetic predisposition may influence surgical management.

•

Highly vascular tumours which may be associated with catecholamine secretion.

•

Comprehensive pre- and intra-operative preparation is essential.

•

Final surgical strategy often requires direct tumour visualisation.

•

The surgical strategy may alter for germline associated tumours.

•

Management should be delivered by experienced multidisciplinary teams.

Clinical outcomes following unilateral adrenalectomy in patients with primary aldosteronism

BACKGROUND

In approximately half of cases of primary aldosteronism (PA), the cause is a surgically-resectable unilateral aldosterone-producing adrenal adenoma. However, long-term data on surgical outcomes are sparse.

AIM

We report on clinical outcomes post-adrenalectomy in a cohort of patients with PA who underwent surgery.

DESIGN

Retrospective review of patients treated for PA in a single UK tertiary centre.

METHODS

Of 120 consecutive patients investigated for PA, 52 (30 male, median age 54, range 30-74) underwent unilateral complete adrenalectomy. Blood pressure, number of antihypertensive medications, and serum potassium were recorded before adrenalectomy, and after a median follow-up period of 50 months (range 7-115). Recumbent renin and aldosterone were measured, in the absence of interfering antihypertensive medication, ≥3months after surgery, to determine if PA had been biochemically cured.

RESULTS

Overall, blood pressure improved from a median (range) 160/95 mmHg (120/80-250/150) pre-operatively to 130/80 mmHg (110/70-160/93), P < 0.0001. 24/52 patients (46.2%) had cured hypertension, with a normal blood pressure post-operatively on no medication. 26/52 (50%) had improved hypertension. 2/52 patients (3.8%) showed no improvement in blood pressure post-operatively. Median (range) serum potassium level increased from 3.2 (2.3-4.7) mmol/l pre-operatively to 4.4 mmol/l (3.3-5.3) post-operatively, P < 0.0001). Median (range) number of antihypertensive medications used fell from 3 (0-6) pre- to 1 post-operatively (range 0-4), P < 0.0001.

CONCLUSIONS

Unilateral adrenalectomy provides excellent long-term improvements in blood pressure control, polypharmacy and hypokalaemia in patients with lateralizing PA. These data may help inform discussions with patients contemplating surgery.

Uterine incarceration in a primigravid retroverted bicornuate uterus

Uterine incarceration is a rare complication that usually occurs after the first trimester of pregnancy. It leads to increased maternal and/or fetal morbidity and mortality. Risk factors include retroversion of uterus and other pelvic abnormalities. Clinical presentation includes severe abdominal and pelvic pain symptoms. Patients can present with concurrent urinary symptoms due to increasing distortion of adjacent structures from the enlarging uterus. A high clinical suspicion of uterine incarceration is confirmed with ultrasound. More advanced imaging such as MRI can be used as an adjunct to ultrasound imaging. Progression from expectant management to intervention is recommended as soon as possible to prevent complications such as uterine rupture and fetal demise. In subsequent pregnancies, close monitoring with serial ultrasounds is warranted to monitor for recurrence of incarceration which has been reported in a few rare cases.

Eplerenone use in primary aldosteronism during pregnancy

Primary aldosteronism (PA) in pregnancy is rare. Due to pharmacological limitations and risks associated with surgical intervention during pregnancy, clinical decision making in this area is difficult. We report the short‐term use of eplerenone in the management of hypertension and hypokalemia due to PA in pregnancy.

Pure aldosterone-secreting adrenocortical carcinoma in a patient with refractory primary hyperaldosteronism

We describe a young male patient with longstanding hypertension, who was diagnosed with primary hyperaldosteronism and treated by an attempted retroperitoneoscopic total unilateral adrenalectomy for a left-sided presumed aldosterone-secreting adenoma. Imaging had shown an unremarkable focal adrenal lesion with normal contralateral adrenal morphology, and histology of the resected specimen showed no adverse features. Post-operatively, his blood pressure and serum aldosterone levels fell to the normal range, but 9 months later, his hypertension recurred, primary aldosteronism was again confirmed and he was referred to our centre. Repeat imaging demonstrated an irregular left-sided adrenal lesion with normal contralateral gland appearances. Adrenal venous sampling was performed, which supported unilateral (left-sided) aldosterone hypersecretion. Redo surgery via a laparoscopically assisted transperitoneal approach was performed and multiple nodules were noted extending into the retroperitoneum. It was thought unlikely that complete resection had been achieved. His blood pressure returned to normal post-operatively, although hypokalaemia persisted. Histological examination, from this second operation, showed features of an adrenocortical carcinoma (ACC; including increased mitoses and invasion of fat) that was assessed as malignant using the scoring systems of Weiss and Aubert. Biochemical hyperaldosteronism persisted post-operatively, and detailed urine steroid profiling showed no evidence of adrenal steroid precursors or other mineralocorticoid production. He received flank radiotherapy to the left adrenal bed and continues to receive adjunctive mitotane therapy for a diagnosis of a pure aldosterone-secreting ACC.

Diagnosing unilateral primary aldosteronism - comparison of a clinical prediction score, computed tomography and adrenal venous sampling

CONTEXT

In patients with primary aldosteronism (PA), adrenalectomy is potentially curative for those correctly identified as having unilateral excessive aldosterone production. It has been suggested that a recently developed and published clinical prediction score (CPS) may correctly identify some patients as having unilateral disease, without recourse to adrenal venous sampling.

OBJECTIVE

We have applied the CPS to a large cohort of PA patients with defined and documented outcomes. We also incorporated a minor modification to the CPS and a radiological grading score (RGS) into our analysis to assess whether its performance could be augmented.

RESULTS

A total of 75 patients with a robust diagnosis following bilateral adrenal venous cannulation and/or strictly defined surgical outcome were analysed. Applying the CPS to this group of patients produced a sensitivity of 38·8% and a specificity of 88·5% of correctly identifying unilateral aldosterone production. Using a suggested modification to the CPS, in which different levels of hypokalaemia were given different weightings, the sensitivity rose to 40·8%, with an identical specificity. Using the RGS alone improved sensitivity to 91·7%, but specificity was reduced to 62·5%.

CONCLUSION

Applying the recently developed CPS to this cohort of patients, it was not possible to reproduce the 100% specificity reported in the original publication. Using the modified score or incorporating the RGS did not improve its performance. In this cohort, we were unable to show superiority of the CPS over an imaging-based strategy. CPS may have a role in guiding clinical decision-making, especially in those whose adrenal venous sampling (AVS) has been unsuccessful.

Optimum duration of neoadjuvant letrozole to permit breast conserving surgery

The aim of this multicenter, prospective, longitudinal phase IV study was to establish the optimal duration of neoadjuvant letrozole that would allow breast conservation surgery (BCS) in patients with early breast cancer who were initially unsuitable. Primary, invasive, estrogen-receptor- and/or progesterone-receptor-positive breast cancer patients, with large tumors (≥T2 i.e., >20 mm) not initially suitable for BCS, received 2.5 mg letrozole p.o. daily. Patients continued treatment until they became eligible for BCS, progressed, failed to meet criteria for BCS and withdrew for scheduled mastectomy, withdrew for other reasons, or completed 12 months of letrozole treatment without a BCS decision being made. A total of 146 patients were enrolled; seven patients who did not have a valid postbaseline tumor assessment were excluded from the final efficacy analysis. At study closure, 69 % of patients (96 of 139) were eligible for BCS. The median time to achieve a tumor response sufficient to allow BCS with neoadjuvant letrozole was 7.5 months (95 % CI 6.3-8.5 months). Letrozole was well tolerated, and most adverse events were mild-to-moderate (grade 1-2). The results from this trial suggest that extended letrozole therapy in the neoadjuvant setting (7.5 months), as opposed to conventional treatment of 4 months, is optimal to achieve maximum reduction in tumor volume sufficient for BCS.

Bed sharing when parents do not smoke: is there a risk of SIDS? An individual level analysis of five major case-control studies

OBJECTIVE

To resolve uncertainty as to the risk of Sudden Infant Death Syndrome (SIDS) associated with sleeping in bed with your baby if neither parent smokes and the baby is breastfed.

DESIGN

Bed sharing was defined as sleeping with a baby in the parents' bed; room sharing as baby sleeping in the parents' room. Frequency of bed sharing during last sleep was compared between babies who died of SIDS and living control infants. Five large SIDS case-control datasets were combined. Missing data were imputed. Random effects logistic regression controlled for confounding factors.

SETTING

Home sleeping arrangements of infants in 19 studies across the UK, Europe and Australasia.

PARTICIPANTS

1472 SIDS cases, and 4679 controls. Each study effectively included all cases, by standard criteria. Controls were randomly selected normal infants of similar age, time and place.

RESULTS

In the combined dataset, 22.2% of cases and 9.6% of controls were bed sharing, adjusted OR (AOR) for all ages 2.7; 95% CI (1.4 to 5.3). Bed sharing risk decreased with increasing infant age. When neither parent smoked, and the baby was less than 3 months, breastfed and had no other risk factors, the AOR for bed sharing versus room sharing was 5.1 (2.3 to 11.4) and estimated absolute risk for these room sharing infants was very low (0.08 (0.05 to 0.14)/1000 live-births). This increased to 0.23 (0.11 to 0.43)/1000 when bed sharing. Smoking and alcohol use greatly increased bed sharing risk.

CONCLUSIONS

Bed sharing for sleep when the parents do not smoke or take alcohol or drugs increases the risk of SIDS. Risks associated with bed sharing are greatly increased when combined with parental smoking, maternal alcohol consumption and/or drug use. A substantial reduction of SIDS rates could be achieved if parents avoided bed sharing.

A prospective evaluation of postural stimulation testing, computed tomography and adrenal vein sampling in the differential diagnosis of primary aldosteronism

CONTEXT

In primary aldosteronism (PA), discriminating unilateral from bilateral disease is crucial because adrenalectomy is frequently curative in the former case but rarely helps in the latter. Various series have reported the utility of postural stimulation testing (PST), cross-sectional imaging and adrenal vein sampling (AVS) in the assessment of PA, but most of these studies were retrospective.

OBJECTIVE

To prospectively determine the diagnostic utility of PST, AVS and computed tomography (CT) using a radiological scoring system in the assessment of PA in a tertiary centre, as well as to document the incidence of autonomous cortisol cosecretion.

DESIGN AND SETTING

Fifty consecutive patients with PA underwent PST, CT, AVS and a low-dose dexamethasone suppression test with measurement of serum cortisol at 48 h. For patients who underwent surgery, histological confirmation, and a normal postoperative serum aldosterone concentration and plasma renin activity were taken as evidence for unilateral disease. For other patients, results from successful adrenal vein sampling were the diagnostic evidence against which CT and PST were assessed.

RESULTS

Postural stimulation testing had a sensitivity and specificity of 44-56% and 71-75%, respectively. CT had an overall sensitivity and specificity of 77% and 80%, respectively, rising to 100% sensitivity and specificity if there was a single, discrete macronodule with an unequivocally normal contralateral gland. Evidence of cosecretion of cortisol occurred in 14% of patients.

CONCLUSIONS

Preliminary experience is presented of an objective radiological scoring system for selecting patients with PA for AVS. PST provides little, if any, useful additional information. A significant minority of patients with PA exhibit evidence of cortisol cosecretion, which may have implications for perioperative management.

Clinical and functional significance of α9β1 integrin expression in breast cancer: a novel cell-surface marker of the basal phenotype that promotes tumour cell invasion

Integrin α9β1 is a receptor for ECM proteins, including Tenascin-C and the EDA domain of fibronectin, and has been shown to transduce TGFβ signalling. This study has examined the expression pattern of α9β1 in 141 frozen breast carcinoma samples and related expression to prognostic indices, molecular subtype and patient outcome. Effects of α9β1 on tumour cell migration and invasion were assessed using blocking antibody and gene transduction approaches. Integrin α9β1 localized to myoepithelial cells in normal ducts and acini, a pattern maintained in DCIS. A subset (17%) of invasive carcinomas exhibited tumour cell expression of α9β1, which related significantly to the basal-like phenotype, as defined by either CK5/6 or CK14 expression. Tumour expression of α9β1 showed a significant association with reduced overall patient survival (p < 0.0001; HR 5.94, 95%CI 3.26-10.82) and with reduced distant-metastasis-free survival (p < 0.0001; HR 6.37, CI 3.51-11.58). A series of breast cancer cell lines was screened for α9β1 with the highly invasive basal-like GI-101 cell line expressing significant levels. Both migration and invasion of this line were reduced significantly in the presence of α9-blocking antibody and following α9-knockdown with siRNA. Conversely, migratory and invasive behaviour of α9-negative MCF7 cells and α9-low MDA MB468 cells was enhanced significantly by over-expression of α9. Thus, α9β1 acts as a novel marker of the basal-like breast cancer subtype and expression is associated with reduced survival, while its ability to promote breast cancer cell migration and invasion suggests that it contributes to the aggressive clinical behaviour of this tumour subtype.

Molecular subtyping of DCIS: heterogeneity of breast cancer reflected in pre-invasive disease

Background:

Molecular profiling has identified at least four subtypes of invasive breast carcinoma, which exhibit distinct clinical behaviour. There is good evidence now that DCIS represents the non-obligate precursor to invasive breast cancer and therefore it should be possible to identify similar molecular subtypes at this stage. In addition to a limited five-marker system to identify molecular subtypes in invasive breast cancer, it is evident that other biological molecules may identify distinct tumour subsets, though this has not been formally evaluated in DCIS.

Methods:

Tissue microarrays were constructed for 188 cases of DCIS. Immunohistochemistry was performed to examine the expression patterns of oestrogen receptor (ER), progesterone receptor (PR), Her2, EGFR, cytokeratin (CK) 5/6, CK14, CK17, CK18, β4-integrin, β6-integrin, p53, SMA, maspin, Bcl-2, topoisomerase IIα and P-cadherin. Hierarchical clustering analysis was undertaken to identify any natural groupings, and the findings were validated in an independent sample series.

Results:

Each of the intrinsic molecular subtypes described for invasive breast cancer can be identified in DCIS, though there are differences in the relative frequency of subgroups, in particular, the triple negative and basal-like phenotype is very uncommon in DCIS. Hierarchical cluster analysis identified three main subtypes of DCIS determined largely by ER, PR, Her2 and Bcl-2, and this classification is related to conventional prognostic indicators. These subtypes were confirmed in an analysis on independent series of DCIS cases.

Conclusion:

This study indicates that DCIS may be classified in a similar manner to invasive breast cancer, and determining the relative frequency of different subtypes in DCIS and invasive disease may shed light on factors determining disease progression. It also demonstrates a role for Bcl-2 in classifying DCIS, which has recently been identified in invasive breast cancer.

Oncological and aesthetic considerations of conservational surgery for multifocal/multicentric breast cancer

Conventional indications for mastectomy (MX) reflect circumstances where breast conserving therapy (BCT) could compromise oncological or cosmetic outcome. MX continues to be recommended for the majority of women with multiple lesions within the same breast. In this article, we review the oncological safety and aesthetic considerations of BCT in the context of multifocal (MF) or multicentric (MC) breast cancer. Literature review facilitated by Medline and PubMed databases. Published studies have reported divergent results regarding the oncological adequacy of BCT in the management of MF or MC disease. Earlier studies demonstrated high rates of local recurrence (LR) for BCT. More recent series have found BCT to be comparable to MX in terms of LR, distant failure, disease free and overall survival. Few studies have adequately evaluated cosmetic outcomes following BCT for MF or MC breast cancer. Contemporary oncoplastic techniques have extended the clinical utility of BCT and are of particular relevance to breast conservation in the context of MF or MC lesions. Appropriate case selection, preoperative oncological and aesthetic planning, satisfactory clearance of the surgical margins and adjuvant radiotherapy are of paramount importance. In the absence of level-1 guidance concerning the management of women with MF or MC disease, each case requires discussion with regard to tumor and patient related factors in the context of the multidisciplinary team. In selected patients with MF or MC disease, BCT is oncologically safe and cosmetically acceptable. Uniformity of practice and the establishment of a standard of care will require an evidence-base from prospective studies.

SDHD-related chromaffin tumours: disease localisation to genetic dysfunction

BACKGROUND/AIMS

To describe the management of a subject with multiple chromaffin tumours found to have a novel succinate dehydrogenase D (SDHD) mutation.

CASE

A 15-year-old boy with marked hypertension was found to have elevated urinary catecholamines and initial imaging thought to represent bilateral adrenal phaeochromocytomas. An adrenal venous catheter was required to clarify a right adrenal phaeochromocytoma and a left abdominal paraganglioma, distinct from the left adrenal gland. Excision of these tumours, with preservation of the left adrenal gland, provided a cure for this subject without the need for lifelong steroid replacement. Genetic analysis revealed a novel SDHD mutation (c. 169 + 1 G>A) which was shown to result in loss of the 5' splice site and exclusion of exon 2 during splicing. This suggests the likely pathogenicity of this mutation. Disease surveillance in this subject and genetic screening of first degree relatives is ongoing.

CONCLUSIONS

Genetic testing should be considered in all subjects presenting with a chromaffin tumour. In certain circumstances an adrenal venous sampling catheter for catecholamines may clarify diagnostic uncertainty. The complex management issues raised in the care of these subjects requires the involvement of a multidisciplinary team with the relevant expertise.

A Multi-Center Study To Determine the Optimum Duration of Neoadjuvant Letrozole on Tumour Regression To Permit Breast Conserving Surgery – An Interim Analysis

Background: Neoadjuvant letrozole is an attractive alternative to chemotherapy for post menopausal women with large, ER positive breast cancer, who are destined for mastectomy but would prefer breast conservation. Prospective studies have not investigated treatment duration beyond 6 months and retrospective studies suggest useful responses can occur after this period.Materials and Methods: This trial is a prospective, UK centrally quality assured, multi-centre, longitudinal study to assess the optimal duration of neoadjuvant letrozole treatment to allow breast conserving surgery for a period of up to12 months. Post menopausal women with large (≥T2), ER and/or PgR positive primary tumours, not considered eligible for breast conservation, were commenced on neoadjuvant letrozole and response was assessed every 2 months with clinical and ultrasound examination until sufficient shrinkage for breast conservation, progression or 12 months had been reached. Ultrasound and Mammography were undertaken at baseline and end-point. We present the initial analysis for time to response and breast conservation.Results: By January 2009, 103 women were available for analysis. 23 (22.3%) had undergone a mastectomy, 60 (58.3%) had achieved breast conservation and 20 (19.4%) remained under evaluation within the trial. The mean age of the group was 74.1 years (52-92). 25 (24.3%) had invasive lobular cancer and 13 (12.6%) had grade 3 tumours. 22 (21.4%) were node positive.Figure 1. Kaplan-Meier plot for time (days) to response sufficient for breast conservation.25% had breast conservation by 5.8 months, 50% by 8.2 months and 75% by 12 months. Median time to breast conservation was 8.2 months (95% CI 6.4-9.3)Figure 2. Median change in tumour volume from baselineAfter an initial rapid response in the first 4 months, the rate of response was slower and constant for a further 6 months. Tumour volume reduction to permit breast conservation varied between 65 and 80% .Discussion: This interim analysis indicates that the conventional treatment period of 4 to 6 months of neoadjuvant letrozole should be revised. For most women longer duration will increase the likelihood of achieving sufficient volume reduction to allow breast conserving surgery.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1082.

The expression and function of IGFBP-3 in normal and malignant breast tissue

The mitogenic and anti-apoptotic effects of insulin-like growth factor-I (IGF-I) are regulated by a family of insulin-like growth factor binding proteins (IGFBPs), particularly IGFBP-3. Little is known about the IGF-independent role of IGFBP-3 in breast cancer and the mechanisms regulating its production. The expression of IGFBP-3 in paired malignant and adjacent normal (n=53), and healthy normal (n=17) breast tissue samples was investigated using RT-PCR, immunohistochemistry and ELISA. We compared IGFBP-3 expression with other members of the IGF-I axis, other known tumorigenic genes and clinicopathological parameters. We also developed a novel tissue explant system using fresh normal and malignant breast tissue, with which we examined the in vitro effects of IGFBP-3 alone and in combination with known apoptotic agent, doxorubicin (n=6), on tissue viability and apoptosis. We demonstrated a high level of expression of IGFBP-3 mRNA in all samples. 96% of samples also expressed IGFBP-3 protein. No significant correlation was seen between IGFBP-3 expression and other clinicopathological parameters. The in vitro tissue explant system demonstrated that IGFBP-3 had little effect by itself on apoptosis. However, when used in combination with doxorubicin, increased apoptosis was seen in tumours. In contrast, less apoptosis was seen in normal tissue suggesting a protective effect. These divergent effects suggest a potential novel chemotherapeutic approach in the treatment of breast cancer. These findings suggest that IGFBP-3 may play a role in tumorigenesis, and that IGFBP-3 levels could be used in the future in cancer risk assessment/prevention or as markers of response to cancer treatments.

Follow-up for screen-detected ductal carcinoma in situ: results of a survey of UK centres participating in the Sloane project

AIMS

To investigate the variations in follow-up practice for screen-detected ductal carcinoma in situ (DCIS) in the UK.

METHODS

A questionnaire enquiring about follow-up practice and the perceived value of clinical follow-up after surgery for screen-detected DCIS was sent to the 74 UK screening centres participating in the Sloane Project.

RESULTS

Responses were received from 66 hospitals serving 54 screening centres. These demonstrate wide variations in practice. Clinical follow-up duration ranges from 1 year to indefinite, with the frequency of visits from three-monthly to annually. Formal mammographic follow-up duration ranges from none to indefinite. Mammographic frequency ranges from 1 to 2 years. Follow-up varies according to factors such as size and grade of disease and margin status in 23 units and according to whether adjuvant therapy is given in 23. Seven hospitals perform mammography of reconstructed breasts. Thirty-one centres consider clinical follow-up of DCIS to be of value or limited value whereas 28 consider it to be of little or no value.

CONCLUSIONS

There is no consensus with regard to the duration and frequency of follow-up for screen-detected DCIS, the contribution of predictive and treatment factors, the use of mammography of the reconstructed breast or the perceived value of clinical follow-up. Published guidelines show no consensus. Multidisciplinary teams involved in the care of women with screen-detected non-invasive cancer should contribute to audits such as the Sloane Project in order to determine the most effective and efficient ways to treat and follow up these patients.

Socio-economic deprivation independently predicts early recurrence in estrogen receptor positive breast cancer

Abstract #6081

Introduction: Socio-economic deprivation is associated with reduced survival in breast cancer, but little is known about how it affects the pattern of disease recurrence. We investigated the relationships between deprivation, other risk factors and recurrence in post-menopausal women with operable ER+ breast cancer.&#x2028; Methods: Patients who underwent potentially curative surgery for ER+ breast cancer between 1995 and 2005 at four UK centres were studied. Those patients whose area of residence was ranked in the highest quintile group according to the appropriate national Index of Multiple Deprivation were classed as deprived. The cumulative risk of recurrence was calculated using the Kaplan-Meier method, and hazard ratios were calculated using conventional and time-dependent Cox regression analysis stratified by centre.&#x2028; Results: 4110 patients were available for analysis, of whom 821 (20.0%) were classed as deprived. The median age at diagnosis was 62 years in both deprived and non-deprived groups. Tumour size and grade did not vary with deprivation status, but nodal involvement (38.0% vs 34.3%, p=0.05, Fisher's exact test) and lymphovascular invasion (28.1% vs 23.6%, p=0.01) were more prevalent in deprived patients. The latter were also more likely to undergo mastectomy (53.3% vs 47.2%, p=0.002) and less likely to receive adjuvant radiotherapy (50.4% vs 58.5%, P&lt;0.001) or chemotherapy (19.1% vs 22.8%, p=0.03).&#x2028; Median follow up was 5 years from diagnosis. Raw cumulative recurrence at 2.5 years was 8.4% (95% confidence interval 6.4-10.4) in deprived and 6.1% (5.3-6.9) in non-deprived patients. At 5 years the corresponding rates were 15.8% (13.1-18.5) and 13.3% (11.9-14.7). Only distant recurrence contributed to this difference, the local and contralateral recurrence rates being almost identical in deprived and non-deprived groups. Time-dependent Cox regression analysis showed that deprivation was a significantly stronger predictor of recurrence within 2.5 years of diagnosis than at later intervals, with or without adjustment for other prognostic variables (p&lt;0.05). For recurrence within 2.5 years, the unadjusted hazard ratio for deprivation was 1.64 (95% CI 1.22-2.22, p=0.001). After adjustment for age, mode of presentation, pathological variables and treatment, the hazard ratio was 1.51 (1.07-2.14, p=0.02).&#x2028; Conclusions: Post-menopausal women with ER+ breast cancer who are resident in areas of high deprivation are at increased risk of early recurrence, independently of known differences in tumour pathology and treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6081.

The role of radiotherapy in treating small early invasive breast cancer

AIM

The aim of the study was to identify if radiotherapy can be safely avoided in a selected subgroup of largely screening detected small invasive breast cancer.

METHODS

One hundred and eighty-eight patients with node negative invasive early breast cancer < or =1cm (< or =T1b) treated in our centre between 1990 and 2004 were retrospectively followed for local, regional and distant recurrences. Treatment involved adequate local excision by breast conserving surgery (BCS). Axillary staging was performed by a four node axillary sampling until 2000, following which sentinel lymph node sampling was employed. All sections were assessed histologically by haematoxylin and eosin stained sections. The inked margins were reported as being involved, close and clear. Radiotherapy (RT) was employed only if the resected margins were inadequate, and in those with involved axillary nodes who refused further completion axillary clearance.

RESULTS

Ninety-four patients (Group A) had BCS alone and 79 patients (Group B) had both BCS and RT. There was no ipsilateral breast tumour recurrence (IBTR) in 88 patients in Group A, corresponding to an actuarial freedom from IBTR of 96%, 91% and 88.1% at 5 years, 8 years and 9 years. In Group B, there was no IBTR in 75 patients corresponding to an actuarial freedom from IBTR of 97%, 94.9% and 90.6% at 5 years, 8 years and 10 years.

CONCLUSION

Our experience over 14 years has shown that it is possible to safely avoid radiotherapy in a selected subgroup of small invasive breast cancer.

Choosing early adjuvant therapy for postmenopausal women with hormone-sensitive breast cancer: aromatase inhibitors versus tamoxifen

AIMS

The aromatase inhibitors (AIs) anastrozole, exemestane, and letrozole have demonstrated superior disease-free survival (DFS) over tamoxifen in several trials. As the choice of adjuvant endocrine treatment for early breast cancer (EBC) is evolving from tamoxifen to the AIs, this review compares the AIs with tamoxifen to help surgeons choose a treatment plan that provides the greatest reduction of recurrence risk for their patients.

METHODS

MEDLINE was searched to identify relevant literature on the adjuvant use of tamoxifen and AIs in EBC.

RESULTS

Despite the use of adjuvant tamoxifen, recurrence is a persistent threat to women with hormone-sensitive EBC. Trials of the AIs versus tamoxifen have established that patients benefit from longer DFS, and in some cases distant DFS, after the use of an AI as initial adjuvant therapy, as switch therapy following 2-3 years of tamoxifen, or as extended adjuvant therapy following 5 years of tamoxifen. The AIs are well tolerated, with a different safety profile than that of tamoxifen in all these settings. Trials addressing the optimal regimen and treatment duration for AIs are also underway.

CONCLUSIONS

The advantage in DFS associated with AIs over tamoxifen use should prompt physicians and patients to consider the use of an AI as the initial adjuvant endocrine therapy or, alternatively, switching patients who currently take tamoxifen to an AI for the remainder of adjuvant endocrine therapy. Prolonging the period of adjuvant therapy with letrozole after 5 years of tamoxifen reduces recurrence and is associated with a survival advantage in node-positive patients.

Methylene blue dye--a safe and effective alternative for sentinel lymph node localization

Sentinel lymph node (SLN) biopsy has emerged as an effective diagnostic tool in axillary staging in breast cancer. The commonly used technique employs isosulfan blue/patent blue V combined with radioactive colloid tracer. Methylene blue (MB) is a less expensive and readily available alternative dye. The study evaluated the safety and efficacy of MB in SLN localization. A retrospective study of 329 patients with early breast cancer who had SLN localization as part of an ethically approved prospective evaluation study of SLN localization technique was carried out. Lymph node positive, tumors >2 cm on clinical and radiological evaluation, those with previous breast and axillary surgery, neo-adjuvant chemotherapy were excluded from the study. One hundred seventy three patients underwent SLN localization using 1 mL of 1% MB, and a combined MB-radio colloid tracer technique was used in the other 156 patients. Allocation to the groups was by simple randomization. Injection of the dye and radioisotope was into the subdermal plane in the sub-areolar region. Patients underwent breast conservation surgery or mastectomy with SLN directed four node axillary sampling +/- axillary clearance. The lymph node was examined by standard microscopy. There were no reported complications with the use of MB aside from temporary tattooing. The technique failed in eight patients giving an identification rate of 97.6%. Ten of the 258 (3.9%) patients had false-negative SLN, with negative predictive value of 96.1%, sensitivity of predicting further axillary disease of 73%, specificity of 87.3%, and overall accuracy of 85.7%. Reported adverse reaction to isosulfan blue/patent blue V varied from minor to severe anaphylactic reactions (1-3%) requiring vigorous resuscitation. Subdermal sub-areolar injection of MB is safe and effective readily available dye for SLN localization in axillary staging of breast cancer with no major adverse reaction.

The prevalence of seat belt use in Kingston, Jamaica: a follow-up observational study five years after the introduction of legislation

An observational cross-sectional study conducted in Kingston in 2004 showed that seat belts were used by 81.2% of private motor vehicle drivers and 74.0% offront seat passengers. This was significantly improved compared to 21.1% and 13.6% respectively in 1996 before the introduction of legislation in 1999 (p < 0.001). Females were significantly more likely than males to wear seat belts, both when driving (92.5% vs 77.3%; p < 0. 001) and as front seat passengers (79.9% vs 66.3%; p < 0.001). Of the 2289 motor vehicles examined, all except one were equipped with seat belts. Rear passenger utilization of seat belts was not examined. Drivers of new vehicles were more likely than other drivers to use seat belts (p < 0.001). Male drivers, drivers of older vehicles and all passengers may require specific targeting in an educational and enforcement campaign if the maximum benefits of seat belt use are to be realized

Methylene blue dye versus combined dye-radioactive tracer technique for sentinel lymph node localisation in early breast cancer

AIM

The study compared the accuracy and success rate of two techniques, methylene blue alone versus combined methylene blue and radioactive colloid in sentinel lymph node localisation in the management early breast cancer.

METHODS

Three hundred and twenty-nine patients with tumours less than 2 cm on ultrasound assessment were prospectively evaluated. One hundred and seventy-three patients (Group A) underwent sentinel lymph node localisation using 1 ml of 1% methylene blue. A combined technique of both methylene blue and radioactive colloid was used in 156 patients (Group B). Application of both was subdermal and subareolar. Sentinel lymph nodes were examined by standard microscopy. Patients underwent breast conservation surgery or mastectomy and sentinel node guided four node axillary sampling+/-clearance.

RESULTS

In Group A, the sentinel lymph node identification rate was 96.5%. The negative predictive value was 96.3%, with false negative of 3.7% and accuracy of 87.4%. In group B the identification rate for sentinel lymph node was 98.7%, with false negative of 4.1%, negative predictive value of 96%, and accuracy of 83.8%.

CONCLUSION

Sentinel lymph node localisation using methylene blue or combined dye and radioactive tracer technique predicts the axillary lymph node status in early breast cancer with comparable success rates, accuracy and false negative rates. The combined technique facilitates quicker identification of sentinel lymph node; however the dye technique alone can be used successfully in centres without nuclear medicine facilities.

Evaluation of the antioxidant potential of grape seed and bearberry extracts in raw and cooked pork

The effect of grape seed extract (GSE) and bearberry (BB), on lipid oxidation (TBARS, mg malondialdehyde (MDA)/kg muscle), colour (CIE 'a' redness value), pH, microbial status (log(10)CFU colony forming units/g pork) and sensorial properties of cooked pork patties was investigated. GSE (0-1000μg/g muscle) and BB (0-1000μg/g muscle) were added to raw pork (M. longissimus dorsi) patties which were stored in modified atmosphere packs (MAP) (75% O(2):25% CO(2)) for up to 12 days at 4°C. Cooked pork patties were stored in MAP (70% N(2):30% CO(2)) for up to 4 days at 4°C. Mesophilic plate counts and pork pH were unaffected by GSE and BB. GSE and BB addition decreased (P<0.05) lipid oxidation (TBARS) in raw pork patties on days 9 and 12 of storage, relative to controls. Antioxidant activity of GSE and BB was observed in cooked pork patties demonstrating the thermal stability of GSE and BB. The 'a' redness values of raw and cooked pork patties marginally increased with increasing GSE concentration. The sensory properties of cooked pork patties were unaffected by GSE and BB addition. Results obtained demonstrate the potential for using health promoting nutraceuticals in meat and meat products.

Parathyroid carcinoma in multiple endocrine neoplasia type 1 (MEN1) syndrome: two case reports of an unrecognised entity

CONTEXT

Primary hyperparathyroidism occurs in almost all patients with the syndrome of multiple endocrine neoplasia type 1 (MEN1), but the association of MEN1 with parathyroid carcinoma has only been described previously in a single patient. In this report, we describe two further cases of parathyroid carcinoma presenting in MEN1 syndrome.

CASE REPORTS

The first patient was a 69-yr-old woman, who presented with severe primary hyperparathyroidism and tracheal compression by a large mediastinal mass, which was shown histologically to be a parathyroid carcinoma with a second similar lesion in the neck. She was treated with total parathyroidectomy followed by resection of the mediastinal mass with resolution of the hypercalemia. Remarkably, she also reported primary amenorrhea and was found to have an invasive pituitary lactotroph adenoma, which was treated with cabergoline and external beam radiotherapy. Magnetic resonance imaging (MRI) of the pancreas revealed a small lesion characteristic of an islet-cell tumor, which was clinically and biochemically non-functioning. The second patient was a 32-yr-old man who presented with symptomatic hypercalemia and markedly raised serum PTH concentration. Neck exploration revealed two parathyroid glands only. One of the parathyroid glands contained a tumor with fibrous banding, atypical mitoses, extra-capsular extension and moderate Ki 67 staining; features which are highly suggestive of carcinoma. He also had intractable dyspepsia associated with raised serum gastrin concentration. A lesion was localized to the neck of the pancreas by endocopic ultrasound, and a selective arterial calcium stimulation catheter suggested the presence of both a gastrinoma and an insulinoma, although he had no hypoglycemic symptoms. Pituitary MRI was normal. The patient's mother had primary hyperparathyroidism.

CONCLUSIONS

This case report describes two further patients in whom parathyroid carcinomas occurred in the context of MEN1, which gives a new insight to the possible presenting phenotype of this condition. Both patients had negative genetic screening for classic MEN1 gene mutation, which may suggest that one or more novel occult mutations may be responsible for this aggressive phenotype.

Selective parathyroid venous sampling in patients with complicated hyperparathyroidism

OBJECTIVE

The role of preoperative localisation of abnormal parathyroid glands remains controversial but is particularly relevant to the management of patients with recurrent or persistent hyperparathyroidism and familial syndromes. We report our experience of the use of selective parathyroid venous sampling (PVS) in the localisation of parathyroid disease in such patients.

DESIGN

We report a retrospective 10-year experience (n = 27) of the use of PVS in complicated primary hyperparathyroidism and contrast the use of PVS with neck ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) and sestamibi imaging modalities.

RESULTS

In 14 out of 25 patients who underwent surgery PVS results were completely concordant with surgical and histological findings and 88% of patients achieved post-operative cure. Out of 13 patients referred after previous failed surgery, 12 underwent further surgery which was curative in 9. In total PVS yielded useful positive (n = 13) and/or negative information (n = 6) in 19 out of 25 patients undergoing surgery. Using histology as the gold standard, 59% of PVS studies were entirely consistent with histology, as compared with 39% of ultrasound scans, 36% of sestamibi scans and 17% of MRI/CT scans.

CONCLUSIONS

PVS is a valuable adjunct to MRI/CT and sestamibi scanning in selected patients with complicated hyperparathyroidism when performed in an experienced unit.

The Farnesoid X Receptor Is Expressed in Breast Cancer and Regulates Apoptosis and Aromatase Expression

Bile acids are present at high concentrations in breast cysts and in the plasma of postmenopausal women with breast cancer. The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily that regulates bile acid homeostasis. FXR was detected in normal and tumor breast tissue, with a high level of expression in ductal epithelial cells of normal breast and infiltrating ductal carcinoma cells. FXR was also present in the human breast carcinoma cells, MCF-7 and MDA-MB-468. Activation of FXR by high concentrations of ligands induced MCF-7 and MDA-MB-468 apoptosis. At lower concentrations that had no direct effect on viability, the FXR agonist GW4064 induced expression of mRNA for the FXR target genes, small heterodimer partner (SHP), intestinal bile acid binding protein, and multidrug resistance-associated protein 2 (MRP-2), and repressed the expression of the SHP target gene aromatase. In contrast to MRP-2, mRNA for the breast cancer target genes MDR-3, MRP-1, and solute carrier transporter 7A5 were decreased. Although multidrug resistance transporters were regulated and are known FXR target genes, GW4064 had no effect on the cell death induced by the anticancer drug paclitaxel. Our findings show for the first time that FXR is expressed in breast cancer tissue and has multiple properties that could be used for the treatment of breast cancer.

Cyclo-oxygenase-2 (COX-2) mRNA expression and hormone receptor status in breast cancer

AIMS

The purpose of this study was to evaluate COX-2 mRNA expression with known clinical prognostic features of breast cancer, oestrogen/progesterone receptor status, tumour size and grade.

METHODS

Total RNA was extracted from 45 frozen breast tumour (invasive) and 22 normal breast tissue samples. COX-2 mRNA transcription was quantified using a real time RT-PCR assay and expressed as copy number/microg total RNA. All specimens were assessed for tumour grade, size, nodal status and presence of vascular invasion and oestrogen and progesterone receptor status.

RESULTS

COX-2 mRNA was detected in all samples with a median copy number of 1.15 x 10(7) for tumours and 6.5 x 10(6) for normal samples. Expression was significantly higher in oestrogen receptor negative tumours compared to the receptor positive group. There was no correlation between COX-2 mRNA levels and tumour size, grade, nodal status and presence of vascular invasion.

CONCLUSIONS

COX-2 mRNA expression is increased in oestrogen and progesterone receptor negative breast cancers.

Role of aromatase inhibitors in breast cancer

Primarily, the role of the aromatase inhibitors has been investigated in postmenopausal women with breast cancer, although it is also now being assessed in premenopausal patients following ovarian ablation/suppression. Aromatase inhibitors markedly suppress endogenous oestrogens without directly interacting with oestrogen receptors, and thus have a different mechanism of action to the antioestrogen, tamoxifen. The inhibitors may be divided into subgroups according to their structure (steroidal and nonsteroidal), and there appears to be a lack of cross-resistance between the classes of aromatase inhibitors enabling them to be used sequentially and potentially to prolong endocrine hormone therapy. In addition, with increased efficacy and favourable safety and tolerability profiles, the aromatase inhibitors are starting to challenge tamoxifen as first choice endocrine treatment in a number of settings. Potential differences in side-effect profiles may appear between the steroidal and nonsteroidal aromatase inhibitors when used in long-term settings. Thus, it has been suggested that the steroidal agents have favourable end organ effects; for example, the steroidal inhibitor, exemestane, has minimal negative effects on bone and lipid metabolism in animal and clinical studies. This paper provides an overview of the current and future roles of aromatase inhibitors for breast cancer treatment.