Native Function of the Bacterial Ion Channel SthK in a Sparsely Tethered Lipid Bilayer Membrane Architecture

The plasma membrane protects the interiors of cells from their surroundings and also plays a critical role in communication, sensing, and nutrient import. As a result, the cell membrane and its constituents are among the most important drug targets. Studying the cell membrane and the processes it facilitates is therefore crucial, but it is a highly complex environment that is difficult to access experimentally. Various model membrane systems have been developed to provide an environment in which membrane proteins can be studied in isolation. Among them, tethered bilayer lipid membranes (tBLMs) are a promising model system providing a solvent-free membrane environment which can be prepared by self-assembly, is resistant to mechanical disturbances and has a high electrical resistance. tBLMs are therefore uniquely suitable to study ion channels and charge transport processes. However, ion channels are often large, complex, multimeric structures and their function requires a particular lipid environment. In this paper, we show that SthK, a bacterial cyclic nucleotide gated (CNG) ion channel that is strongly dependent on the surrounding lipid composition, functions normally when embedded into a sparsely tethered lipid bilayer. As SthK has been very well characterized in terms of structure and function, it is well-suited to demonstrate the utility of tethered membrane systems. A model membrane system suitable for studying CNG ion channels would be useful, as this type of ion channel performs a wide range of physiological functions in bacteria, plants, and mammals and is therefore of fundamental scientific interest as well as being highly relevant to medicine.

Abstract P5-16-17: Titanium-coated polypropylene mesh for immediate implant-based breast reconstruction – Our initial experience

Background: The use of titanium-coated polypropylene mesh (TCPM) is an alternative to a-cellular dermal matrix for the implant based breast reconstruction by providing extra implant coverage especially in the lower half. The aim of our study was to analyze short-term outcomes of TCPM based implant breast reconstruction and compare the patient- and procedure-related factors to implant loss and surgical complications.

Methods: Between 2013and 2016, implant breast reconstructions after conservative mastectomies using TCMP was performed in 50 patients (with 58 reconstructions). Complications were divided into major (need for additional surgery), minor (conservative treatment), and implant loss. Univariate analyses were performed to determine the influence of the patient- and procedure-related factors on postoperative complications and implant loss.

Results: Fifty patients had therapeutic mastectomies with 8 of them also had contra lateral risk reducing mastectomies. With median follow-up of 17.5 months, four of 50 patients had implant loss. Reasons for implant loss were skin necrosis in 2 cases, infection in 1 case and necrosis with infection in another case. One of these patients had a revised reconstruction one year later. One additional patient required implant replacement because of capsule contracture. No risk factors were observed for patient-associated complications. Univariate analysis revealed an increased risk for implant loss in patients with skin necrosis (p < 0.01).

Conclusions: This titanium-coated polypropylene mesh shows acceptable complication rates and its use in immediate implant breast reconstruction is safe and effective.

Citation Format: Munir A, Holt S, Huws A, Khan S, Shariaha Y, Khawaja S. Titanium-coated polypropylene mesh for immediate implant-based breast reconstruction – Our initial experience [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-16-17.

TGF-β1 modifies histone acetylation and acetyl-coenzyme A metabolism in renal myofibroblasts

Histone acetylation is an important modulator of gene expression in fibrosis. This study examined the effect of the pre-eminent fibrogenic cytokine TGF-b1 on histone 3 (H3) acetylation and its regulatory kinetics in renal myofibroblasts. Fibroblasts propagated from rat kidneys after ureteric obstruction were treated with recombinant TGF-b1 or vehicle for 48 hours. TGF-b1 -induced myofibroblast activation was accompanied by a net decrease in total H3 acetylation, although changes in individual marks were variable. This was paralleled by a generalised reduction in histone acetyltransferases (HAT), and divergent changes in histone deacetylase (HDAC) enzymes at both transcript and protein levels. Globally this was manifest in a reduction in total HAT activity and increase in HDAC activity. TGF-b1 induced a shift in cellular metabolism from oxidative respiration to aerobic glycolysis resulting in reduced acetyl-CoA. The reduction in total H3 acetylation could be rescued by providing exogenous citrate or alternative sources of acetyl-CoA, without ameliorating changes in HAT/HDAC activity. In conclusion, TGF-b1 produces a metabolic reprogramming in renal fibroblasts, with less H3 acetylation through reduced acetylation, increased deacetylation and changes in carbon availability. Our results suggest that acetyl-CoA availability predominates over HAT and HDAC activity as a key determinant of H3 acetylation in response to TGF-b1.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Effect of ractopamine hydrochloride (Optaflexx) dose and duration on growth performance and carcass characteristics of finishing steers

Three experiments evaluated the effects of ractopamine hydrochloride (RAC) dose and duration on growth performance and carcass characteristics of feedlot steers. In total, 1,509 crossbred steers (530 kg initial BW [SD 22]) were used in a randomized complete block design using a 3 × 3 factorial treatment structure. Treatments consisted of RAC dose (0, 100, or 200 mg/steer daily) and duration (28, 35, or 42 d) of RAC feeding prior to harvest. Initiation of RAC dose was staggered (7 d apart) based on RAC duration, which resulted in common days on feed among treatments. Data from the 3 experiments were combined for statistical analyses. There were no RAC dose × duration interactions ( ≥ 0.85) for growth performance. Live final BW was not different ( ≥ 0.24) as RAC dose increased. Dry matter intake linearly decreased ( < 0.01) as RAC dose increased. Live ADG and G:F linearly increased ( ≤ 0.01) as RAC dose increased. Carcass-adjusted ADG and G:F linearly increased ( ≤ 0.02) as RAC dose increased. Compared with steers fed 0 mg RAC/steer daily, G:F was improved by 5.0 and 13.0% when steers were fed 100 ( = 0.31) and 200 ( = 0.01) mg RAC/steer daily, respectively. Hot carcass weight tended ( = 0.10) to linearly increase as RAC dose increased, with carcasses from steers fed 100 ( = 0.38) and 200 ( = 0.10) mg RAC/steer daily being 2.2 and 4.1 kg heavier, respectively, than carcasses from steers fed 0 mg RAC/steer daily. Increasing RAC dose linearly ( < 0.01) increased LM area and linearly ( = 0.02) decreased marbling score. Live final BW was not different ( ≥ 0.60) among RAC durations. Carcass-adjusted final BW, ADG, and G:F were not different ( ≥ 0.41) as RAC duration increased. Carcass traits did not differ ( ≥ 0.18) among RAC duration. Feeding 200 mg RAC/steer daily improved ADG, feed efficiency, and HCW. Increasing the feeding duration of RAC had no effect of growth performance or carcass characteristics. These data indicate that feeding 200 mg RAC/steer daily for 28 d improves steer growth performance.

Peritoneal dialysis practice in Australia and New Zealand: A call to sustain the action

This paper updates a previous 'Call to Action' paper (Nephrology 2011; 16: 19-29) that reviewed key outcome data for Australian and New Zealand peritoneal dialysis patients and made recommendations to improve care. Since its publication, peritonitis rates have improved significantly, although they have plateaued more recently. Peritoneal dialysis patient and technique survival in Australian and New Zealand have also improved, with a reduction in the proportion of technique failures attributed to 'social reasons'. Despite these improvements, technique survival rates overall remain lower than in many other parts of the world. This update includes additional practical recommendations based on published evidence and emerging initiatives to further improve outcomes.

Abstract P2-01-22: The long term outcomes of Metasin RTqPCR intra-operative sentinel node analysis in early breast cancer

Background:

Axillary lymph node involvement is a prognostic factor in breast cancer and it is used to guide adjuvant therapy. Axillary clearance remains the standard of care in lymph node positive disease in most parts of the world. Usually this is performed as second procedure but immediate intra-operative node analysis allows clearance to be performed as part of the initial procedure where necessary.

The Metasin assay targets the breast epithelial cell markers CK19 and mammaglobin mRNA and detects the presence of breast tissue (metastatic disease) in the sentinel nodes. Evidence shows the Metasin assay to be fast (average assay time 41.2min) and accurate with a discordance rate below 4% compared with histology. The cost effectiveness of the assay has been reported in our previous studies.

Aim:

The aim of this study is to assess the risk of axillary recurrence following the use of the Metasin assay to guide axillary management.

Method:

This is a single centre retrospective study which included all patients presenting to a district general hospital with early clinically node negative breast cancer undergoing sentinel node biopsy between Oct 2011 and Dec 2014.

Alternate 2 mm slices of the node were examined intraoperatively using the Metasin assay and the remainder sent for histological examination. The results of the Metasin assay and histology were compared. The risk of axillary recurrence using the Metasin test to select patients for immediate axillary clearance was assessed.

Results:

1073 sentinel nodes from 545 patients were analysed during this three-year period. 2 patients were lost to follow up. 94 patients were node positive and underwent axillary clearance as part of their primary surgery. 449 patients had sentinel node biopsy with no further axillary procedure. There were 36 nodes (3.34%) with discordant results. Median follow up was 32 months (range 18 to 55 months).

Fourteen patients presented with recurrences (2.56%). The mean event free interval was 15 months. Of the 14 patients, 5 patients tested with Metasin had macrometastases and underwent immediate axillary clearance during the primary surgery. 7 patients were node negative and 2 patients were shown to have micrometastases. 11 patients recurred with distant metastases, 3 patients with local recurrence and 2 patients (0.36%) with axillary recurrences.

The two axillary recurrences occurred at 3 and 5 months after primary surgery. Both patients underwent Metasin intraoperative analyses of sentinel nodes which were negative. Subsequent histological examination confirmed no metastatic node involvement in one patient but micro-metastases in the other. Both of these patients had aggressive disease with local, axillary and distant metastasis and subsequently died of their disease.

Conclusions:

The Metasin assay is a reliable intraoperative test for sentinel node involvement and when used to guide surgical axillary management is associated with very low axillary recurrences (0.36% with a median follow up of 32 months).

Citation Format: Udayasankar S, Ashley E, Jenkins KS, Huws A, Sharaiha Y, Sai-Giridhar P, Thomas D, Munir A, Holt S, Khawaja S. The long term outcomes of Metasin RTqPCR intra-operative sentinel node analysis in early breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-22.

Abstract P1-05-21: A comparison of oncotype DX recurrence scores in a screen detected vs a symptomatic cohort of patients with breast cancer: A UK experience

Background:

In the Western World, it has been stated that breast cancers detected on a screening program are indolent. There have been many recent publications stating that breast screening is overdiagnosing and therefore overtreating patients with breast cancer. With the advent of genomic testing, it can now be determined which patients have an aggressive tumor requiring systemic chemotherapy. We therefore conducted a retrospective study in the UK on patients having oncotype DX testing in both screen detected and symptomatic cancers.

Materials and Methods:

Patients in our institution undergoing oncotype DX testing for invasive breast cancer which was ER positive and node negative were part of this study. The detection of the breast cancer was documented as either a screening case or a symptomatic one. The recurrence scores of the oncotype DX testing was then compared in the screening versus the symptomatic cohort.

Results:

155 patients were included in this study. They underwent Oncotype DX testing between 2008 to 2016. The age of the patients ranged from between 31 years to 78 years. Eighty-nine patients were reported to have a low recurrence score; 45 had an intermediate score; and 21 had a high result. Fifty eight patients were screen detected, while 97 patients were symptomatic presentations. In the screening population, 32 patients had a low recurrence score; 22 had an intermediate result and 4 had a high recurrence score resulting in the latter groups being considered for chemotherapy. In the symptomatic cohort, 57 had a low recurrence score; 23 had an intermediate result; and 17 had a high score.

Conclusion:

The results of our study depict that even patients in a screeining cohort will have a high number of intermediate recurrence scores and some with a high recurrence score. This shows that the hypothesis that screening detects a majority of breast cancers which are indolent not requiring further systemic treatment should be looked at again in light of our results with genomic testing.

Citation Format: Khawaja S, Parab A, Thomas D, Huws A, Munir A, Udayasankar S, Sharaiha Y, Holt S. A comparison of oncotype DX recurrence scores in a screen detected vs a symptomatic cohort of patients with breast cancer: A UK experience [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-21.

Abstract P1-03-12: A simulation study depicting the inconsistency of adjuvant online compared to genomic testing when determining the benefit of chemotherapy

Background: Prognostic factors have been used for years to determine the benefit of adjuvant chemotherapy in breast cancer. However, reporting of the size and grade of the tumor are affected by interobserver variability in reporting. This can result in a change in the results of adjuvant online and an impact on decision making of chemotherapy. On the contrary, genomic testing such as oncotype Dx is reproducible. The purpose of our study was to assess the effect of pathological discordance on the adjuvant online results on a cohort of patients who also underwent oncotype Dx testing.

Materials and Methods: A total of 143 patients' histologies were included in this study. The results of the Phase III WSG-Plan B trial concerning central vs. local grade discrepancy rates were utilized to randomly change the grade of the tumors. 61 percent of grade 1 cancers were upgraded to grade 2 and 2% upgraded to grade 3. 4 percent of grade 2 cancers were downgraded to grade 1 and 26% were upgraded to grade 3. 1 percent of grade 3 cancers were downgraded to grade 1 and 25% were downgraded to grade 2. Likewise, change was made in the size of the tumor in 20 percent of patients. 8 to 10mm, 18-20, 28-30, and 48-50mm changed to 11, 21, 31 and 51mm respectively. 11-13mm, 21-23, 31-33, and 51-53mm was changed to 10, 20, 30, and 50mm. Ten percent of patients had the ER and Her 2 status changed.

Results: The simulation results showed that when the grade was only altered, the spearman correlation of the predicted 10 year mortality on adjuvant online with the original data was significantly changed from 1 to a result of 0.788. When the changed size was additionally added, the coefficient was 0.836. With the altered ER status, the result was 0.749 and with the Her 2 change, the spearman correlation was minimally changed to 0.742. The scattergrams showed a large number of outliers when the alteration in size was added to the altered grade.

Conclusion: Our simulation study confirms that with minimal changes in the clinical parameters because of the lack of perfect correlation between pathologist's results, there is a significant difference in the 10 year predicted mortality on adjuvant online. This is one step further in understanding the lack of correlation between adjuvant online and oncotype Dx, and the inconsistency of chemotherapy decision making with the sole use of adjuvant online.

Citation Format: Khawaja S, Thomas D, Udayasankar S, Munir A, Huws A, Sharaiha Y, Holt S. A simulation study depicting the inconsistency of adjuvant online compared to genomic testing when determining the benefit of chemotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-03-12.

[Pulmonary hypertension associated with left heart disease: recommendations of the Cologne Consensus Conference 2016]

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. While the guidelines contain detailed recommendations regarding pulmonary arterial hypertension (PAH), they contain only a relatively short paragraph on other, much more common forms of PH such as PH due to left heart disease. Despite the lack of data, targeted PAH treatments are increasingly being used for PH associated with left heart disease. This development is of concern because of limited ressources and the need to base treatments on scientific evidence. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease, representing an unmet need of targeted PH therapies. It that sense, the practical implementation of the European Guidelines in Germany requires the consideration of several specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, several working groups were initiated, one of which was specifically dedicated to PH associated with left heart disease. This article summarizes the results and recommendations of this working group.

Changing maternal perceptions of healthy feeding: a novel intervention

OBJECTIVE

This study sought to better understand factors influencing mothers' perceptions about healthy feeding. Additionally, a social consensus intervention was used to try to change mothers' likelihood to serve healthy foods.

METHODS

Mothers saw photographs of healthy and unhealthy snacks and meals and rated them on several factors that were hypothesized to predict the likelihood of serving the foods. Then, mothers were randomly assigned to the experimental or control condition. Those in the experimental condition received social consensus information about these foods, whereas the control condition did not. The change in perceptions in the control and experimental conditions was examined.

RESULTS

Mothers rated healthy meals and snacks less favourably than unhealthy meals and snacks on factors including cost, preparation time and difficulty, and child preference. Furthermore, mothers' perceptions of foods as liked by their child, easy to prepare and 'kid-friendly' predicted higher likelihood to serve those foods. Finally, mothers were more likely to describe the healthy snack as kid-friendly and indicated being more likely to serve it after receiving favourable social norm information about the food.

CONCLUSIONS

The use of social consensus interventions to change parents' perceptions of healthy snacks may be one means of increasing the quality of children's diets.

Unhealthy Alcohol Use

Unhealthy alcohol use is common and routine screening is essential to identify patients and initiate appropriate treatment. At-risk or hazardous drinking is best managed with brief interventions, which can be performed by any provider and are designed to enhance patients' motivations and promote behavioral change. Alcohol withdrawal can be managed, preferably with benzodiazepines, using a symptom-triggered approach. Twelve-step programs and provider-driven behavioral therapies have robust data supporting their effectiveness and patients with alcohol use disorder should be referred for these services. Research now support the use of several FDA-approved medications that aid in promoting abstinence and reducing heavy drinking.

An adsorbent monolith device to augment the removal of uraemic toxins during haemodialysis

Adsorbents designed with porosity which allows the removal of protein bound and high molecular weight uraemic toxins may improve the effectiveness of haemodialysis treatment of chronic kidney disease (CKD). A nanoporous activated carbon monolith prototype designed for direct blood contact was first assessed for its capacity to remove albumin bound marker toxins indoxyl sulphate (IS), p-cresyl sulphate (p-CS) and high molecular weight cytokine interleukin-6 in spiked healthy donor studies. Haemodialysis patient blood samples were then used to measure the presence of these markers in pre- and post-dialysis blood and their removal by adsorbent recirculation of post-dialysis blood samples. Nanopores (20-100 nm) were necessary for marker uraemic toxin removal during in vitro studies. Limited removal of IS and p-CS occurred during haemodialysis, whereas almost complete removal occurred following perfusion through the carbon monoliths suggesting a key role for such adsorbent therapies in CKD patient care.

Is lymphatic endoglin expression a risk marker for breast cancer metastasis? Results of a pilot study

BACKGROUND

Studies have identified endoglin as a biological marker that is overexpressed on the microvessels of certain solid cancers (breast, colorectal cancer, and head and neck squamous cell cancers). There is, at present, no immunohistochemical marker that can discriminate between lymph node-negative and or lymph node-positive breast cancer tissue.

METHODS

The expression of endoglin was quantified by immunohistochemistry and assessment of microvessel density in 53 surgical specimens. These were comprised of breast tumor tissue that had not spread to the regional lymph nodes (lymph node-negative breast tumor tissue: 20 specimens), breast tumor tissue had spread to regional lymph nodes (lymph node-positive breast tumor tissue: 21 specimens), and normal breast tissue as a control (12 specimens).

RESULTS

Significant difference was observed between the expression of endoglin on microvessels of lymph node-negative and lymph node-positive breast cancer tissue (p<0.05). This significant difference was shown to be due to endoglin expression on lymphatic vessels (p<0.02), rather than on blood vessels (p>0.05).

CONCLUSIONS

These findings are the first to suggest that endoglin expression on breast tumor lymphatic vessels may have diagnostic potential as a discriminator between lymph node-negative and lymph node-positive breast cancer. Further studies would be required to confirm this.

Is lymphatic endoglin expression a risk marker for breast cancer metastasis?

The following abstracts won prizes at the 153rd East Midlands Surgical Society meeting held on 9 November 2012 at Leicester General Hospital. First prize was won by George et al. The paper by Ogunbiyi et al was placed second and the paper by Khanna et al was placed third.

A decision impact, decision conflict and economic assessment of routine Oncotype DX testing of 146 women with node-negative or pNImi, ER-positive breast cancer in the U.K

Background:

Tumour gene expression analysis is useful in predicting adjuvant chemotherapy benefit in early breast cancer patients. This study aims to examine the implications of routine Oncotype DX testing in the UK.

Methods:

Women with oestrogen receptor positive (ER+), pNO or pN1mi breast cancer were assessed for adjuvant chemotherapy and subsequently offered Oncotype DX testing, with changes in chemotherapy decisions recorded. A subset of patients completed questionnaires about their uncertainties regarding chemotherapy decisions pre- and post-testing. All patients were asked to complete a diary of medical interactions over the next 6 months, from which economic data were extracted to model the cost-effectiveness of testing.

Results:

Oncotype DX testing resulted in changes in chemotherapy decisions in 38 of 142 (26.8%) women, with 26 of 57 (45.6%) spared chemotherapy and 12 of 85 (14.1%) requiring chemotherapy when not initially recommended (9.9% reduction overall). Decision conflict analysis showed that Oncotype DX testing increased patients' confidence in treatment decision making. Economic analysis showed that routine Oncotype DX testing costs £6232 per quality-adjusted life year gained.

Conclusion:

Oncotype DX decreased chemotherapy use and increased confidence in treatment decision making in patients with ER+ early-stage breast cancer. Based on these findings, Oncotype DX is cost-effective in the UK setting.

Abstract P1-01-18: The results of 55 consecutive cases of intra-operative sentinel node analysis using real time polymerase chain reaction detection of cytokeratin 19 and mammoglobin expression (Metasin) to direct immediate axillary clearance

The standard management of early beast cancer is complete excision of the primary from the breast by either wide local excision or mastectomy and sentinel node biopsy to stage the axilla. The standard of care in the UK remains clearance of the axilla in node positive patients. Unless immediate multiple frozen section histology is available, positive patients require a second operation between 3 and 6 weeks later, with the associated increased cost, inconvenience and risk.

By using the real time polymerase chain reaction (PCR) to detect mammary derived cells in the sentinel lymph nodes (SLN), we aim to provide the surgeon with a reliable indicator of the presence or absence of nodal macro-metastases within a timeframe that will allow axillary clearance to be performed under the same anaesthetic as the initial surgery. We detect cytokeratin 19 (CK19) or mammoglobin within the lymph node using reagents developed by the UK National Health Service under the name Metasin.

Method: 55 consecutive patients undergoing SLN biopsy as part of their initial treatment for early breast cancer were tested using the Metasin. The nodes were divided into 2mm slices and alternate sections submitted to PCR and the remainder to conventional histology. The results were compared and an assessment of the costs made. The time taken report the Metasin result to the surgeon was recorded.

Results: Five patients had positive results by Metasin and proceeded to immediate axillary clearance. When compared to histology there were no false positive results (0%). Two patients were negative on Metasin testing with the threshold set at 2 mm but positive on histology (3.6%). The average time for the test was 43.2 minutes and the mean number of lymph nodes was 2.3. The average cost is £40 to test 2 nodes.

Discussion: The test is accurate. The two false negative cases were found to be due to the sampling, the metastases being only present by chance in the histologically examined specimens and not due to assay failure. The total cost to run the test for 55 patients was £2,520. The cost for completion axillary clearance as a separate procedure is estimated at £2,227. The total saving for 5 cases is about £11,000, making the test cost saving as well as safer, more acceptable to the patients and limiting delay in starting adjuvant therapies. The additional time of surgery caused by using Metasin was minimal.

Conclusion: Metasin has become our standard of care in patients requiring SLN biopsy and generally avoids second surgeries to clear the axilla in positive cases. We are considering analyzing the complete node using this technique and this would eliminate false negatives caused by sampling and offer further cost savings in the histology department.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-01-18.

p53 levels in human mammary epithelial cells expressing wild-type and mutant human papillomavirus type 16 (HPV-16) E6 proteins

Human fibroblast cells must overcome both the M1 and the M2 stages of cellular senescence to immortalize, at which point cells almost always express telomerase activity. The human papillomavirus (HPV) oncoproteins, HPV-16 E6 and E7, can block the progression to senescence in fibroblasts by associations with p53 and pRb, respectively. Human mammary epithelial (HME) cells require only HPV-16 E6 to bypass M1, suggesting that pRb may not have a direct role in HME cells senescence. In the present report, we show that only wild-type HPV-16 E6 allows complete degradation of p53, immortalization and reactivation of telomerase activity in HME cells. These results suggest that the ability of HPV-16 wild-type and mutant E6 proteins to degrade p53 in intact HME cells and keratinocytes does not completely correlate with their ability to degrade p53 in a cell-free system. This discrepancy between in vitro and in vivo p53 degradation may be biologically significant and may provide insight into the susceptibility of certain human cells and tissues for reactivation of telomerase and immortalization.

Genetics of colorectal cancer (Review)

There is an increasing awareness of the genetic basis of colon cancer and the application of gene therapy. The most commonly altered oncogenes are c-Ki-ras and c-myc, with less frequent involvement of c-src and c-erb. The loss of heterozygosity (LOH) on chromosome 5q has been frequently associated with adenomas, occurring on 17q, 18q, 1p35, 8p22 and 22q11-13 loci. This results in a loss of tumor suppressor gene for these chromosomes. The LOH on 5q was noted on the adenomatous polyposis coli (APC) and the gene on chrome-some 5 was mutated in over 55% cases of colorectal cancer, termed mutated in colon cancer (MCC). MCC is regarded as a tumor suppressor gene which is responsible for the initiation of colon cancer. The deleted in colon cancer gene (DCC) on 18q21 is a common cause of adenomas and the LOH on 17q in p53 gene are frequently seen in bowel cancer. Comparison of frequency with which tumor suppressor and oncogenes are altered in the adenomas and carcinomas suggests that there is a preferred order for their occurrence in the adenoma-carcinoma sequence. Our studies indicate that supplement with tumor suppressor oncoprotein may open a new avenue for gene therapy of colorectal cancer but steps in the identification of the gene(s) await further exploration.

Electrometric direct current I/V converter with wide bandwidth

A principle of operation and electrical characteristics of a high frequency current-to-voltage (I/V) converter are presented. The I/V converter measures the electric current with selectable gains of 10(5), 10(4), and 10(3) V/A in the frequency range from DC to 500 kHz, 1.2 MHz, and 2.4 MHz, respectively. These properties make this I/V converter suitable for wide range of applications such as tuning forks, torsion oscillators, ultrasound transducers measurements, detection of the piezoelectric transducers used in STM techniques, etc., in low temperature physics. The influence of the input impedance of a I/V converter on the precision of alternating current measurements is also discussed.

Hepatitis B virus related membranous glomerulonephritis and proteinuria treated with lamivudine and tenofovir

Membranous glomerulonephritis is the most common histological renal lesion associated with hepatitis B virus (HBV) infection. The authors describe here a case of a patient presenting with the nephrotic syndrome and HBV infection but without progressive liver disease. The use of lamivudine and tenofovir resulted in arrest of proteinuria and stabilisation of renal function.

Why do hospital mastectomy rates vary? Differences in the decision-making experiences of women with breast cancer

BACKGROUND

Hospital mastectomy rates vary. This study explores the relationship between mastectomy rates and breast cancer patients' consultation and decision-making experiences with specialist clinicians.

METHODS

Qualitative semi-structured interviews were conducted with 65 patients from three purposively selected breast units from a single UK region. Patients provided with a choice of breast cancer surgery (breast conservation therapy (BCT) or mastectomy) were purposively recruited from high, medium and low case-mix-adjusted mastectomy rate units.

RESULTS

Low mastectomy rate unit patients' consultation and decision-making experiences were markedly different to those of the medium and high mastectomy rate breast units. Treatment variation was associated with patients' perception of the most reassuring and least disruptive treatment; the content and style of information provision (equipoise or directed); level of patient participation in decision making; the time and process of decision making and patient autonomy in decision making. The provision of more comprehensive less directive information and greater autonomy, time and support of independent decision making were associated with a lower uptake of BCT.

CONCLUSION

Variation in hospital mastectomy rates was associated with differences in the consultation and decision-making experiences of breast cancer patients. Higher mastectomy rates were associated with the facilitation of more informed autonomous patient decision making.