21 research outputs found
Triboranate Derivatives of Calcium and Strontium
This contribution reports the alkaline earth-mediated formation of homonuclear sigma bonding between the metalloid element, boron. The resultant triborane anions result from the formal dismutation of bis(pinacolato)diboron (B2pin2) and the generation of putative heavier group 2 boryl intermediates. Initial reactions of the heavier alkaline earth bis-(trimethylsilyl)amides, [Ae{N(SiMe3Ā¬)2}2] (Ae = Ca or Sr), with an equimolar quantity of bis(pinacolato)diboron (B2pin) provided the 4-coordinate group 2 silazide diborane adducts [Ae(B2pin2){N(SiMe3Ā¬)2}2] in which the diborane acts as a bidentate ligand via 2-O,O' coordination. Reaction of the calcium species at 60 C with a further three molar equivalents of B2pin2 induced the elimination of pinBN(SiMeĀ¬3)2 and the formation of the bis-triboranate derivative, [Ca(B3pin3)2], in which the 6-coordinate calcium centre is bound in a 3-O,O',O''-coordination mode Ā¬by the three contiguous pinacolate oxygen atoms of both catena-B(sp2)-B(sp3)-B(sp2) bonded anions. Although analogous treatment of [Ae(B2pin2){N(SiMe3Ā¬)2}2] provided similar triboranate anion formation, in this case two equivalents of the strontium silazide were retained within the structure of the trimetallic species, [Sr(B3pin3)2(Sr{N(SiMe3)2}2)2]. Despite these contrasting outcomes both triboranate complexes provide rare examples of catena-boron species beyond the common diboranes, (R2Ā¬B-BR2), in which the homologated unit is propagated by electron precise and otherwise unsupported B-B bonds
MARIA M4:clinical evaluation of a prototype ultrawideband radar scanner for breast cancer detection
A microwave imaging system has been developed as a clinical diagnostic tool operating in the 3- to 8-GHz region using multistatic data collection. A total of 86 patients recruited from a symptomatic breast care clinic were scanned with a prototype design. The resultant three-dimensional images have been compared āblindā with available ultrasound and mammogram images to determine the detection rate. Images show the location of the strongest signal, and this corresponded in both older and younger women, with sensitivity of [Formula: see text] , which was found to be maintained in dense breasts. The pathway from clinical prototype to clinical evaluation is outlined
Beliefs About Medication and Uptake of Preventive Therapy in Women at Increased Risk of Breast Cancer: Results From a Multicenter Prospective Study
Introduction
Uptake of preventive therapies for breast cancer is low. We examined whether women at increased risk of breast cancer can be categorized into groups with similar medication beliefs, and whether belief group membership was prospectively associated with uptake of preventive therapy.
Patients and Methods
Women (n = 732) attending an appointment to discuss breast cancer risk were approached; 408 (55.7%) completed the Beliefs About Medicines and the Perceived Sensitivity to Medicines questionnaires. Uptake of tamoxifen at 3 months was reported in 258 (63.2%). The optimal number of belief groups were identified using latent profile analysis.
Results
Uptake of tamoxifen was 14.7% (38/258). One in 5 women (19.4%; 78/402) reported a strong need for tamoxifen. The model fit statistics supported a 2-group model. Both groups held weak beliefs about their need for tamoxifen for current and future health. Group 2 (38%; 154/406 of the sample) reported stronger concerns about tamoxifen and medicines in general, and stronger perceived sensitivity to the negative effects of medicines compared with group 1 (62%; 252/406). Women with low necessity and lower concerns (group 1) were more likely to initiate tamoxifen (18.3%; 33/180) than those with low necessity and higher concerns (group 2) (6.4%; 5/78). After adjusting for demographic and clinical factors, the odds ratio was 3.37 (95% confidence interval, 1.08-10.51; P = .036).
Conclusion
Uptake of breast cancer preventive therapy was low. A subgroup of women reported low need for preventive therapy and strong medication concerns. These women were less likely to initiate tamoxifen. Medication beliefs are targets for supporting informed decision-making
HER2-enriched subtype and novel molecular subgroups drive aromatase inhibitor resistance and an increased risk of relapse in early ER+/HER2+ breast cancer
BACKGROUND: Oestrogen receptor positive/ human epidermal growth factor receptor positive (ER+/HER2+) breast cancers (BCs) are less responsive to endocrine therapy than ER+/HER2- tumours. Mechanisms underpinning the differential behaviour of ER+HER2+ tumours are poorly characterised. Our aim was to identify biomarkers of response to 2 weeksā presurgical AI treatment in ER+/HER2+ BCs. METHODS: All available ER+/HER2+ BC baseline tumours (n=342) in the POETIC trial were gene expression profiled using BC360ā¢ (NanoString) covering intrinsic subtypes and 46 key biological signatures. Early response to AI was assessed by changes in Ki67 expression and residual Ki67 at 2 weeks (Ki672wk). Time-To-Recurrence (TTR) was estimated using Kaplan-Meier methods and Cox models adjusted for standard clinicopathological variables. New molecular subgroups (MS) were identified using consensus clustering. FINDINGS: HER2-enriched (HER2-E) subtype BCs (44.7% of the total) showed poorer Ki67 response and higher Ki672wk (p<0.0001) than non-HER2-E BCs. High expression of ERBB2 expression, homologous recombination deficiency (HRD) and TP53 mutational score were associated with poor response and immune-related signatures with High Ki672wk. Five new MS that were associated with differential response to AI were identified. HER2-E had significantly poorer TTR compared to Luminal BCs (HR 2.55, 95% CI 1.14ā5.69; p=0.0222). The new MS were independent predictors of TTR, adding significant value beyond intrinsic subtypes. INTERPRETATION: Our results show HER2-E as a standardised biomarker associated with poor response to AI and worse outcome in ER+/HER2+. HRD, TP53 mutational score and immune-tumour tolerance are predictive biomarkers for poor response to AI. Lastly, novel MS identify additional non-HER2-E tumours not responding to AI with an increased risk of relapse
Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK āAlert Level 4ā phase of the B-MaP-C study
Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated āstandardā or āCOVID-alteredā, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had āCOVID-alteredā management. āBridgingā endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2ā9%) using āNHS Predictā. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of āCOVID-alteredā management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown
Coherent ultrasonic Doppler tomography
Ultrasonic imaging based on the pulse-echo principle is widely used throughout the world, particularly in medical applications. However, its spatial resolution is poor (around 2 times the wavelength, or 200 Ī¼m at 15 MHz), limiting its ability to detect small but clinically important lesions (such as microcalcifications in breast cancer). The work presented here is different from the traditional approach. Continuous-wave ultrasound is transmitted to insonate a rotating object, then the amplitude and phase of the returned signals are coherently processed to reconstruct a Doppler tomographic image of the objectās backscatter field. It is demonstrated numerically that the spatial resolution is up to 0.19 wavelengths and the sampling requirement and image formation method are given. To show the performance of the method, we present the results obtained by applying the new technique in simulation and experiment. A string phantom consisting of very thin copper wires and two cylindrical phantoms constructed by tissue-mimicking-material were scanned. It is demonstrated that the copper wires were located very accurately with very high spatial resolution, and good shape approximation for the cylindrical phantoms was achieved