Subarachnoid Haemorrhage Incidence Pattern Analysis with Circular Statistics

Knowledge about biological rhythms of diseases may not only help in understanding the pathophysiology of diseases but can also help health service policy makers and emergency department directors to allocate resources efficiently. Aneurysmal subarachnoid haemorrhage (SAH) has high rates of morbidity and mortality. The incidence of SAH has been attributed to patient-related factors such as characteristics of aneurysms, smoking, and hypertension. There are studies showing that the incidence of aneurysmal SAH appears to behave in periodic fashions over long time periods. However, there are inconsistencies in the literature regarding the impact of chronobiological factors such as circadian, seasonal, and lunar cycle factors on the occurrence of SAH. In this study, we focused on the analysis of a temporal pattern of SAH (infradian rhythms) with a novel approach using circular statistical methods. We aimed to see whether there is a circular pattern for the occurrence of SAH at all and if so, whether it can be related to known temporal patterns based on available literature. Our study did not support the notion that aneurysmal subarachnoid haemorrhages occur on any specific day in a cycle with specific lengths up to 365 days including specific weekdays, full moon, equinoxes, and solstices. Hence, we found no relationship between SAH incidence and timing. Study in larger populations using similar circular statistical methods is suggested.

Hypofractionated Radiotherapy for Hematological Malignancies during COVID-19 Pandemic and Beyond

PURPOSE/OBJECTIVE(S)

Conventionally fractionated radiotherapy (RT) has shown to have excellent local control in hematological malignancies (HM). Up to date there is none or scant literature about the use of hypofractionated radiotherapy (HFRT) for the treatment of HM, this single institution study analyzed the efficacy of HFRT in HM. We hypothesized that HFRT in HM will result in a similar local tumor control that has been reported with standard fractionated RT.

MATERIALS/METHODS

In this retrospective study, we analyzed the data from patients within the provincial cancer registry diagnosed with HM treated with a curative intent using HFRT regimens suggested by International Lymphoma Radiation Oncology Group between 2020-2022 during the COVID-19 pandemic. Primary outcome of the study was overall response rate (ORR), measured as complete response (CR), partial response (PR) or stable disease (SD) within the irradiated field determined radiologically or clinically post completion of RT. Secondary end point was freedom from local progression (FFLP), calculated from the date of initiation of RT to the first date among in-field progression, death, and last follow-up. Summary statistics were used to describe cohort and treatment characteristics. FFLP was calculated by 1 minus cumulative incidence accounting for competing risk (i.e., death).

RESULTS

Of the 36 patients included for analysis, 18 were aggressive non-Hodgkin lymphoma (NHL), 9 were indolent NHL, 6 were Hodgkin lymphoma (HL) and 3 were other HM. Among them 25 had consolidation RT and 11 had definitive RT. HFRT daily dose per fraction ranged from 2.67 Gy to 5 Gy and total dose regimens ranged from 18 Gy to 42.5 Gy in 6 - 17 fractions and median equivalent dose in 2 Gy fractions (EQD2) for alpha/beta = 10Gy was 36 Gy (±7.5). ORR for the entire cohort was 94.4%. With a median follow up of 13.2 months, FFLP at one year for the entire cohort was 91.5% and death without infield progression was 8.7%. Among the 4 patients who had in radiation field recurrence, 2 had aggressive NHL and 2 had HL. No grade 3 or 4 acute toxicities were reported.

CONCLUSION

This retrospective study using HFRT showed an ORR and FFLP comparable to historical studies using standard fractionation. Further long-term follow-up is warranted to confirm these findings.

Implementation and Safety of a Single Fraction Peripheral Lung SBRT during the Global COVID-19 Pandemic, a Single Institution's Experience

Purpose/Objective(s)

In response to the COVID-19 pandemic, a single fraction peripheral lung SBRT program was established to minimize potential COVID-19 exposures. This analysis aims to review clinical and treatment characteristics and associated toxicities in appropriately selected patients for this newly implemented technique.

Materials/Methods

From May 2020 until Feb 2022, patients with peripheral lung tumors who met eligibility for 3400cGy in a single-fraction SBRT were treated at a tertiary academic cancer center. Patient, treatment, and toxicity parameters were retrospectively collected. Radiation dosimetric parameters were tabulated. Toxicities were quantified using CTCAE v5.0. Fisher's exact test was used to assess the differences in toxicities with clinical and dosimetric parameters. P-value < 0.05 was considered significant.

Results

23 patients were analyzed with a median age of 72 years (IRQ: 67-80) and 61% were females. 96% were smokers and 43% had COPD. All patients were ECOG ≤ 2. Majority of patients (96%) had early-stage primary lung cancer while 4% had pulmonary oligometastatic cancer. 39% of patients were treated on SABR-BRIDGE protocol while another 35% were medically inoperable and 26% refused surgery. A total of 23 peripheral lesions were treated with median greatest dimension of 1.7 cm (IQR: 1.4-2), ITV 4.9 cm³ (IQR: 3.6-8.4) and PTV 18.1 cm³ (IQR: 12.8-26). 87% had PTV within 1 cm form chest wall. After median follow-up of 6 months (IQR: 2-12), 52% of patients experienced grade ≤ 2 toxicities and no patients experienced ≥ grade 3. Radiation pneumonitis was the most common toxicity (35%; 5/8 with asymptomatic radiographic) followed by fatigue (30%) and chest wall pain (30%; 3/7 with grade 2). Two patients (9%) had rib fractures. Chest wall pain was significantly higher in patients with tumor diameter >1.5 cm (p = 0.02). No other significant difference was observed between clinical or dosimetric parameters and development of radiation pneumonitis or chest wall pain (p > 0.05). On the other hand, patients with ribs fractures were observed to have larger tumors (mean 3.2 vs. 1.7 cm), ITVs (mean 30 vs. 11 cm³), PTVs (mean 61 vs. 16 cm³), chest wall V30_Gy (mean 4.8 vs. 0.4 cm³), and ribs V30_Gy (mean 1.1 vs. 0.1 cm³). Only 1 patient had local failure after 12 months while another patient on SABR-BRIDGE underwent surgical resection after 6 months in which there were 20% viable tumor cells.

Conclusion

Single fraction peripheral lung SBRT is a practical and safe option with no grade ≥ 3 toxicity. Our observed toxicities are within previously reported ranges. We observed that patients with rib fractures had larger tumors and higher V30_Gy to chest wall and ribs. Careful patient selection and dosimetric efforts to limit high fall-off dose to chest wall and ribs may limit these toxicities.

A17 TRP53 REGULATES ESLF-RENEWAL AND CELL DIFFERENTIATION IN KRT15+ INTESTINAL STEM CELLS

Background

Different pools of stem cells assure the intestinal epithelium homeostasis and regeneration. We recently reported that Krt15+ intestinal cells harbor self-renewal, multipotent and regenerative capacities, characteristics consistent with a stem cell population. p53 has been associated with the development of various types of cancer, and recent studies suggested it also regulates adult stem cell behavior in some tissues. However, its role in the maintenance of intestinal stem cells has not been explicitly covered. Therefore, we hypothesize that Trp53 loss specifically in Krt15+ intestinal stem cells will perturb the epithelial homeostasis and differentiation.

Aims

Identify the role of Trp53 in the regulation of intestinal stem cell and intestinal homeostasis

Methods

To induce Trp53 loss specifically in Krt15+ cells, we generated Krt15 CrePR1;Trp53fl/fl ( Krt15△Trp53) mice and induced Cre recombination by injecting RU486 (PR agonist). Mice were euthanized after Cre recombination at different time points. Organoid cultures were established from control and experimental mice.

Results

Two-month post Cre recombination, we observed no major morphological changes in the intestinal epithelium. However, we observed that crypts isolated from Krt15△Trp53 mice died rapidly and had difficulties forming organoids. When hyperactivating the Wnt/beta-catenin pathway through CHIR treatment, we observed that budding capacity was maintained in experimental organoids while control organoids formed mainly cysts as expected. We also observed an increased in Paneth cell-specific genes, suggesting an enrichment in Paneth cells. Interestingly, the expression of EpHB2 receptor and its target genes was decreased in organoids derived from Krt15△Trp53 mice. Ephrin signaling plays a crucial role in intestinal homeostasis by regulating cell position and migration, and previous studies suggest that ephrin receptors are a target of p53. Indeed, twelve-month post Cre recombination, altered architecture of crypt and villi was noted in the small intestinal epithelium of Krt15△Trp53 mice. Differentiation towards secretory cell types, specifically Paneth, goblet, and tuft cells, are significantly increased in Krt15△Trp53 mice. Interestingly, we also observed crypt cells expressing both goblet and Paneth cell markers suggesting dysfunction in the cell fate decision. Finally, decreased Notch pathway activation was also observed supporting that Trp53 loss, specifically in Krt15+ cells, leads to a dysregulation of secretory cell fate.

Conclusions

Loss of Trp53 specifically in Krt15+ cells affects the small intestinal homeostasis and secretory cell differentiation. Decreased Notch and ephrin signaling support the possible role of Trp53 in cell fate decision and self-renewal.

Funding Agencies

None

Protective effects of L-arginine on cognitive deficits and biochemical parameters in an experimental model of type-2 diabetes mellitus induced Alzheimer's disease in rats

Alzheimer's disease (AD) has been closely linked to type 2 diabetes mellitus (T2DM) and insulin resistance plays a key role in the onset and development of AD. It has also been reported that NO donors play an important role in diabetes and have neuroprotective activity. The present study evaluated the effects NOS substrate, L-arginine and NOS-blocker, NG-nitro-L-arginine methyl ester (L-NAME) on cognitive functions, brain amyloid β levels and other associated biochemical markers in diabetes (T2DM)-induced AD in rats. T2DM was induced by a combination of high fat diet (HFD) and streptozotocin (STZ) (35 mg/kg, i.p.). Pretreatment with L-arginine (100 mg/kg/day) improved diabetes related biochemical parameters viz. plasma glucose, triglycerides and cholesterol. In addition, L-arginine also improved insulin levels and glucose tolerance. On the other hand, NO synthase inhibitor, L-NAME (10 mg/kg), did not have much influence on these parameters. Further, L-arginine treatment showed ameliorative effects on cognitive deficits seen in the Morris water maze (MWM) test when compared to the vehicle (saline) treated group and similar results were observed in the passive avoidance test. These neurobehavioural changes were associated with predictable modulations in Aβ levels in hippocampus and cortex in HFD + STZ + saline group, which were attenuated in the L-arginine, but not in the L-NAME-treated group. Our results indicate that L-arginine could be a considered a potential therapeutic strategy to attenuate the diabetes induced cognitive deficits in AD.

Molecular detection of Salmonella isolated from commercial chicken

BACKGROUND

Salmonella in chicken, specially, the motile salmonellae, causes the food chain unsafe from farm to table and is considered a significant global threat to public health.

AIMS

The present study was carried out for molecular detection of Salmonellae in commercial poultry using PCR.

METHODS

The study was conducted for eight months, from July 2019 to February 2020, and a total of 26 poultry farms, including 15 broiler and 11-layer farms, were visited individually. Pooled faecal samples were obtained from the sheds. A total of 189 necropsy cases were examined for gastrointestinal lesions. Isolation and identification of the organism were done using microbe culture method, and the molecular characterization was performed via PCR targeting invA and ent genes.

RESULTS

The prevalence of salmonellosis in the broiler and layer farms was recorded at 20.0% and 45.4%, respectively, through the traditional gold standard culture method. From 189 necropsy birds, salmonellosis was recorded at 1.58% dead cases. Molecular detection of Salmonella isolates by PCR targeting invA gene was confirmed in 13.33% of the broiler farms and 36.3% of the layer farms. Further detection of Salmonella enteritidis was performed by PCR targeting ent gene by which 11.11% positivity was determined.

CONCLUSION

This study, focused on the Salmonella prevalence, highlighted the zoonotic importance of the bacterium in the commercial poultry farms, which can subsequently be dispersed into the human food chain causing harmful health effects.

Adherence to evidence-based processes of care reduces one-year mortality after aneurysmal subarachnoid hemorrhage (aSAH)

BACKGROUND

There is limited research on the provision of evidence-based care and its association with outcomes after aneurysmal subarachnoid hemorrhage (aSAH).

AIMS

We examined adherence to evidence-based care after aSAH and associations with survival and discharge destination. Also, factors associated with evidence-based care including age, sex, Charlson comorbidity index, severity scores, and delayed cerebral ischemia and infarction were examined for association with survival and discharge destination.

METHODS

In a retrospective cohort (2010-2016) of all aSAH cases across two comprehensive cerebrovascular centres, we extracted 3 indicators of evidence-based aSAH care from medical records: (1) antihypertensives prior to aneurysm treatment, (2) nimodipine, and (3) aneurysm treatment (coiling/clipping). We defined 'optimal care' as receiving all eligible processes of care. Survival at 1 year was obtained by data linkage. We estimated (1) proportion of patients and characteristics associated with receiving processes of care, (2) associations between processes of care with 1-year mortality using cox-proportional hazard model and discharge destination with log binomial regression adjusting for age, sex, severity of aSAH, delayed cerebral ischemia and/or cerebral infarction and comorbidities. Sensitivity analyses explored effect modification of the association between processes of care and outcome by management type (active versus comfort measures).

RESULTS

Among 549 patients (69% women), 59% were managed according to the guidelines. Individual indicators were associated with lower 1-year mortality but not discharge destination. Optimal care reduced mortality at 1 year in univariable (HR 0.24 95% CI 0.17-0.35) and multivariable analyses (HR 0.51 95% CI 0.34-0.77) independent of age, sex, severity, comorbidities, and hospital network.

CONCLUSION

Adherence to processes of care reduced 1-year mortality after aSAH. Many patients with aSAH do not receive evidence-based care and this must be addressed to improve outcomes.

Odderon Exchange from Elastic Scattering Differences between pp and pp[over ¯] Data at 1.96 TeV and from pp Forward Scattering Measurements

We describe an analysis comparing the pp[over ¯] elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM cross sections, extrapolated to a center-of-mass energy of sqrt[s]=1.96  TeV, are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the pp cross section. The two data sets disagree at the 3.4σ level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in pp scattering for which the significance is between 3.4σ and 4.6σ. The combined significance is larger than 5σ and is interpreted as the first observation of the exchange of a colorless, C-odd gluonic compound.

Sexual fantasies, subjective satisfaction and quality of sexual life in patients of sexual dysfunction: A comparative study

Introduction

Exploring the ways in which sexual fantasies may affect sexual experience and satisfaction is of relavence in the clinical setting involving sexual dysfuntion.

Objectives

To observe how the sexual fantasy scores differ in their relationship with sexual satisfaction, experience and quality between sexual dysfunction cases and normal controls.

Methods

Scales included: Wilson’s sex fantasy questionnaire (WSFQ), Arizona Sexual Experience Scale (ASEX), Sexual Quality of life Questionnaire (SQoL), and a subjective sexual satisfaction meter. Differences in resposes of both groups on WSFQ (item-wise and domain-wise) were analysed using T-tests. Two-way ANOVA was applied to see how other scales affected sexual fantasy.

Results

Cases scored significantly higher on ASEX scale, and low on satisfaction, SQoL and WSFQ

	Cases N=1OO	Controls N=100	t-test
Satisfaction Mean(sd)	4.27(1.85)	7.82(1.31)	t=3.052;df=198,p=0.0026
Asex	17.52(4.73)	8.28(1.34)	t=15.24;df=198,p<0.0001
SQoL	29.41(12.12)	49.5(6.67)	t=14.52;df=198,p<0.0001
WSFQ	26.80(17.61)	30.59(15.32)	t=1.62,df=98,p=0.106

Majority of WSFQ responses, both in cases and controls, fell in the intimate and impersonal domains. Sexual fantasy scores and sexual satisfaction had a strong positive and significant correlation in controls but no linear correlation in the case-subjects. sexual fantasy scores contributed to 5.7% of difference in the scores of SQoL between groups. Major variance in scores of satisfaction in our subjects depended on presence or absence of sexual dysfunction(46.5%)but sexual fantasies also contributed to 8.8% of the variance.

Conclusions

The study showed that fantasies contribute to positive sexual outcomes only in absence of sexual dysfunction. ANOVAanalysis revealed that in case-subjects sexual satisfaction briefly increases initially with increase in fantasy scores but starts to decline as fantasies increase.

Disclosure

No significant relationships.

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A149 TRP53 LOSS IN KRT15+ INTESTINAL STEM CELLS SEVERELY AFFECTS SECRETORY CELL FATE AND SELF-RENEWAL

Background

Intestinal epithelium homeostasis is maintained by two main populations of stem cells: Lgr5+ and reserve stem cells. Under injury, cell plasticity has been observed in progenitor and differentiated cells. We recently reported that Krt15+ cells are present in small intestinal and colon epithelia, and harbor self-renewal, multipotent and regenerative capacities. As in Lgr5+and reserve stem cells, hyperactivation of Wnt/b-catenin pathway in Krt15+ stem cells lead to tumor formation in the intestinal epithelium. While these intestinal stem cell populations can act as tumor-initiating cells in sporadic colon cancer, little is known about the cell-of-origin of colitis-associated colon cancer (CAC). TP53 alteration is reported as an early event in CAC. Therefore, we hypothesize that Trp53 loss specifically in Krt15+ stem cells will perturb the epithelial homeostasis and lead to tumor formation.

Aims

Identify if Krt15+ cells may act as the cell-of-origin in colitis-associated colorectal cancer

Methods

To induce Trp53 loss specifically in Krt15+ cells, we generated Krt15-CrePR1;Trp53fl/fl (Krt15△Trp53) mice, induced Cre recombination by injecting RU486 (PR agonist) and euthanized the mice at different time points following recombination.

Results

Results

Twelve-month following Cre recombination, adenoma formation was observed in a small proportion of Krt15△Trp53 mice. Though, Trp53 loss in Krt15+ cells severely perturbed the small intestinal morphology in every mouse studied. Increased crypt length and villi width was observed in Krt15△Trp53 vs control mice without any changes in cell proliferation. We also observed an increased number of Tuft cells and goblet cells in the villi of experimental mice. In the crypt, higher number of Paneth cells and aberrant presence of goblet cells were noted in Krt15△Trp53mice. Interestingly, we also observed crypt cells expressing goblet and Paneth cell markers and decreased Notch pathway activation suggesting dysregulation of secretory cell fate. Krt15△Trp53 mice display higher number of fibroblasts in the villi and the submucosa, as well as thickening of the muscularis layer. Interestingly, similar observations (accumulation of secretory cells and fibrosis) have been reported in IBD patients, supporting the possible role of Krt15+ cells in CAC. Furthermore, crypts isolated from Krt15△Trp53 mice rapidly die when seeded as organoids vs crypts from control mice, suggesting that the alterations observed in vivo in Paneth cells might interfere with the stem cell niche and therefore reduce self-renewal of Krt15+ cells.

Conclusions

Trp53 loss specifically in Krt15+ cells impaired cell fate decision, induced secretory cell hyperplasia, affected self-renewal ability, and initiated adenoma formation supporting the possible role of Krt15+ cells in gut inflammation and cancer.

Funding Agencies

Canada Research Chair, Cancer Research Society, CFI

Clinical Outcomes after Minimally Invasive Trans-Psoas Lateral Lumbar Interbody Fusion for the Treatment of Adult Degenerative Scoliosis: Four Years’ Multicenter Study

The use of minimally invasive transpsoas lateral lumbar interbody fusion (LLIF) surgery for treatment of adult degenerative scoliosis is rapidly increasing in popularity. However, limited data is available regarding its use in adult degenerative lumbar scoliosis surgery. The objective of this study was to evaluate the clinical outcomes of adults with degenerative lumbar scoliosis who were treated with minimally invasive LLIF. Thirty-two consecutive patients with adult degenerative scoliosis treated by a single surgeon at two spine centers were followed up for an average of 13.2 months. Interbody fusion was completed using the minimally invasive LLIF technique with supplemental 360 degrees’ posterior instrumentation. Oswestry disability index (ODI) scores were obtained preoperatively and at most recent follow-up. Complications were recorded. The study group demonstrated improvement in clinical outcome scores. ODI scores improved from 36.8 to 23.4 (p < 0.00001). A total of four complications (12%) were recorded, and two patients (6%) required additional surgery. Based on the significant improvement in validated clinical outcome scores, minimally invasive LLIF can be considered an effective procedure in the treatment of adult degenerative scoliosis.

Restoring spinopelvic harmony with lateral lumbar interbody fusion: is it a realistic goal?

Background

The importance of spinopelvic harmony [pelvic incidence (PI) = lumbar lordosis (LL) ±10 degrees] is well established in the literature. We aimed to determine whether lateral lumbar interbody fusion (LLIF) surgery in isolation is successful in restoring spinopelvic harmony, and whether the surgery maintained the relationship in those who present in a balanced state.

Methods

A retrospective radiographic analysis was performed on patients who underwent LLIF surgery, followed by posterior instrumented fusion, between January 2012 to August 2019 by a single surgeon (AD). Pre- and post-operative X-rays were reviewed by two authors using Surgimap spinal imaging 2.2.15.5. The LL, PI, and PI-LL mismatch, as well as a range of coronal and segmental sagittal radiographic parameters, were recorded.

Results

A total of 71 patients with 170 levels treated via LLIF were analysed. A mean pre-operative PI-LL of 14.3 degrees and post-operative value of 13.4 degrees was recorded (P=0.43). Of the 41 patients who were imbalanced pre-operatively, 13 (31.7%) were restored to a LL within 10 degrees of PI post-LLIF procedure. 30 patients presented in spinopelvic harmony, and 25 (83.3%) of those maintained that relationship following LLIF. Mean coronal global Cobb angles (13.7 degrees pre-operatively to 7.7 degrees post-operatively), segmental coronal Cobb angles (3.8 to 0.9 degrees), and anterior (5.2 to 9.8 mm) and posterior (3.2 to 6.7 mm) disc heights all improved significantly post-LLIF surgery (P<0.0001).

Conclusions

Although an effective treatment for coronal deformities and providing indirect decompression for degenerative lumbar disc disease, LLIF surgery alone is unlikely to result in correction of sagittal deformity and in particular spinopelvic harmony.

Does dissemination of guidelines alone increase the use of palliative single-fraction radiotherapy? Initial report of a longitudinal change management campaign at a provincial cancer program

Background

Despite level 1 evidence demonstrating the equivalence of single-fraction radiotherapy (sfrt) and multiple-fraction radiotherapy (mfrt) for the palliation of painful bone metastases, sfrt remains underused. In 2015, to encourage the sustainable use of palliative radiation oncology resources, CancerCare Manitoba disseminated, to each radiation oncologist in Manitoba, guidelines from Choosing Wisely Canada (cwc) that recommend sfrt. We assessed whether dissemination of the guidelines influenced sfrt use in Manitoba in 2016, and we identified factors associated with mfrt.

Methods

All patients treated with palliative radiotherapy for bone metastasis in Manitoba from 1 January 2016 to 31 December 2016 were identified from the provincial radiotherapy database. Patient, treatment, and disease characteristics were extracted from the electronic medical record and tabulated by fractionation schedule. Univariable and multivariable logistic regression analyses were performed to identify risk factors associated with mfrt.

Results

In 2016, 807 patients (mean age: 70 years; range: 35-96 years) received palliative radiotherapy for bone metastasis, with 69% of the patients having uncomplicated bone metastasis. The most common primary malignancies were prostate (27.1%), lung (20.6%), and breast cancer (15.9%). In 62% of cases, mfrt was used-a proportion that was unchanged from 2015. On multivariable analysis, a gastrointestinal [odds ratio (or): 5.3] or lung primary (or: 3.3), complicated bone metastasis (or: 4.3), and treatment at a subsidiary site (or: 4.4) increased the odds of mfrt use.

Conclusions

Dissemination of cwc recommendations alone did not increase sfrt use by radiation oncologists in 2016. A more comprehensive knowledge translation effort is therefore warranted and is now underway to encourage increased uptake of sfrt in Manitoba.

Neurosurgery in a Case of Suspected Prion Disease: Challenges Faced

This report refers to a rare case of a patient with suspected prion disease and the steps taken for the infection control measures in postsurgical management of a large sphenoid wing meningioma. Stringent measures are needed to prevent the transmission of Creutzfeldt–Jakob disease (CJD) to other patients or healthcare workers. The main concern, especially in a neurosurgical case, is the handling of highly infective tissue and hence the higher risk of disease transmission. This report provides guidance based on the experience in this case, as an aid to similar surgeries.

A31 ALTERED SMALL INTESTINAL EPITHELIAL HOMEOSTASIS AND CELL FATE DECISION UPON LOSS OF TRP53 IN KRT15+ INTESTINAL STEM CELLS

Background

Intestinal homeostasis is mainly maintained by two groups of stem cells: Lgr5+ stem cells and reserve stem cells. Recently, we reported that Krt15+ cells are present in small intestinal and colon epithelia, and harbor self-renewal, multipotent and regenerative capacities. Initiation of sporadic colorectal cancer has been described in Krt15+ stem cells, Lgr5+ stem cells and reserve stem cells following the loss of Apc. While these intestinal stem cell (ISC) populations can act as tumor-initiating cells in sporadic colon cancer, little is known about the cell-of-origin of colitis-associated colon cancer. TP53 alteration is reported as an early event in colitis-associated colon cancer cases. Therefore, we hypothesize that Trp53 loss specifically in Krt15+ stem cells will perturb the epithelial homeostasis and lead to tumor formation

Aims

Identify if Krt15+ cells may act as the cell-of-origin in colitis-associated colorectal cancer.

Methods

To induce Trp53 loss specifically in Krt15+ cells, we generated Krt15-CrePR1;Trp53fl/fl (Krt15△Trp53) mice, induced Cre recombination by injecting RU486 (PR agonist) and euthanized the mice after 12 months following recombination. Histological analysis was performed on small intestinal tissues.

Results

Results: Trp53 loss in Krt15+ cells severely perturbed small intestinal morphology. Increased crypt (proliferative compartment) length correlated with no proliferation changes surprisingly but higher number of Paneth cells and abnormal presence of goblet cells. Interestingly, we also observed the presence of cells expressing both Paneth and goblet cells markers suggesting a deregulation of secretory cell fate decision. Decreased expression of Hes1 and increased β-catenin nuclear expression in the small intestinal crypt of Krt15△Trp53 mice suggest altered Notch and Wnt signaling. Furthermore, villi (differentiated compartment) were significantly wider and shorter, and showed accumulation of activated fibroblasts. Finally, we observed inflammatory lesions as well as adenomas in the small intestine of Krt15△Trp53 mice which remain to be further characterized

Conclusions

Conclusion: In summary, Trp53 loss specifically in Krt15+ cells impaired cell fate decision, induced inflammation and initiated tumor formation. Overall, these results suggest that Krt15+ cells could act as the cell-of-origin of colitis-associated colon cancer.

Funding Agencies

Cancer Research Society, CRC Tier 2

A comparison of lancets and evaluation of various manoeuvres in reducing finger prick pain during pre-donation haemoglobin estimation

OBJECTIVES

Three different types of lancets have been compared to identify and implement the one that causes the least pain. Simple manoeuvres during the lancing procedure have been evaluated to determine their effectiveness in reducing the intensity of perceived pain.

BACKGROUND

Pre-donation haemoglobin estimation is performed by pricking the donor's finger with a lancet. Pain associated with the procedure causes fear and anxiety, which dissuades the donors from donating blood.

METHODS

In 100 subjects, finger prick was performed using three different lancets, and the subjects were asked to score their pain on a numerical rating scale (NRS). A further 150 blood donors were subjected to routine finger pricking for Hb estimation and were asked to score their pain on an NRS. After 15 min, they underwent a second prick with application of a manoeuvre (breath holding, coughing trick or looking away) and again marked their pain scores on the NRS.

RESULTS

Participants reported the least pain scores with lancing devices that have a spring mechanism to retract the lancets soon after penetration into the skin. Breath holding and the cough trick manoeuvre reduced the perceived pain scores significantly.

CONCLUSION

Lancing devices merit consideration for routine use, and a simple manoeuvre may be applied to reduce perceived pain.

Oncological benefits of postoperative radiotherapy in node-negative early stage cancer of the oral cavity with isolated perineural invasion

Perineural invasion has been widely regarded as a poor prognostic factor in cancer of the oral cavity, but adjuvant treatment based only on this is still debatable. We have made an effort to address the question in a retrospective analysis of data from 2009-15 of patients with early node-negative cancers of the oral cavity. Patients with perineural invasion were divided into those who were treated with radiotherapy and those who were not. The records of a total of 169 patients were analysed, and 118 were given adjuvant radiotherapy and 51 were not. The median (range) duration of follow up was 45 (26-86) months. Of 169 patients, 47 (28%) developed recurrence, 28 in the treated, and 19 in the untreated, group. There was a significant disease-free survival benefit for adjuvant treatment (p = 0.047) but no overall survival benefit (p = 0.54). We conclude that adjuvant radiotherapy should be considered for patients with perineural invasion, even in early cancers of the oral cavity.

Incidence of spinal disease and role of spinal radiotherapy in multiple myeloma

Background

Spinal disease (spd) in multiple myeloma (mm) can be a major source of morbidity in newly diagnosed patients and long-term survivors. We retrospectively assessed the incidence of spinal disease in patients newly diagnosed with myeloma, its effect on survival, and the possible effect of spinal radiation therapy (rt).

Methods

Patients diagnosed with mm between 2010 and 2014 were identified through the provincial cancer registry. Plain radiography, computed tomography, and magnetic resonance imaging were reviewed to detect and document the type of spd. Data related to rt and systemic therapy were collected. Kaplan-Meier and time-varying Cox regression models were used to describe overall survival.

Results

Of 306 identified patients with newly diagnosed mm, 51% had spd, including 17% with lytic disease, 68% with compression fractures, and 15% with spinal cord compression. Of the patients with spd, 61% received spinal rt. Of those patients, 84% received spinal rt within 3 months after their diagnosis. Median dose was 20 Gy. Most patients (89.2%) received chemotherapy, and 22.5% underwent autologous stem-cell transplantation. Only 6 of the patients treated with spinal rt received re-irradiation to the same site. Overall survival was similar for patients with and without spd. On multivariate analysis, spinal rt had no effect on survival.

Conclusions

In patients newly diagnosed with mm, spd is a common presentation. With current systemic therapy, the presence of spd had no adverse effect on overall survival. The effect of spinal rt on overall survival was nonsignificant.

Structural changes in cellular membranes induced by ionic liquids: From model to bacterial membranes

Ionic liquids (ILs) have generated considerable attention recently because of their cytotoxicity and application as antibiotics. However, the mechanism of how they damage cell membranes is not currently well understood. In this paper, the antibacterial activities of two imidazolium-based ILs, namely 1-butyl- 3-methylimidazolium tetrafluroborate ([BMIM][BF4]) and 1-ethyl- 3-methylimidazolium tetrafluroborate ([EMIM][BF4]) have been investigated. The activity of [BMIM][BF4] on gram negative bacteria E. coli is observed to be stronger compared with the short chained [EMIM][BF4]. To explain this observation, the effects of these ILs on the self-assembled structures of model cellular membranes have been investigated. The in-plane elasticity of a monolayer formed at air-water interface by 1,2-dipalmitoyl- sn-glycero- 3-phosphocholine (DPPC) lipids was reduced in the presence of the ILs. The x-ray reflectivity studies on polymer supported lipid bilayer have shown the bilayer to shrink and correspondingly exhibit an increase in electron density. The presence of a certain mol% of negatively charged lipid, 1,2-dipalmitoyl-rac-glycero-3-phospho-L-serine (DPPS), in DPPC mono- and bi-layers enhances the effect considerably.

Measurement of the Effective Weak Mixing Angle in pp[over ¯]→Z/γ^{*}→ℓ^{+}ℓ^{-} Events

We present a measurement of the effective weak mixing angle parameter sin^{2}θ_{eff}^{ℓ} in pp[over ¯]→Z/γ^{*}→μ^{+}μ^{-} events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at the Fermilab Tevatron Collider and corresponding to 8.6  fb^{-1} of integrated luminosity. The measured value of sin^{2}θ_{eff}^{ℓ}[μμ]=0.23016±0.00064 is further combined with the result from the D0 measurement in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} events, resulting in sin^{2}θ_{eff}^{ℓ}[comb]=0.23095±0.00040. This combined result is the most precise measurement from a single experiment at a hadron collider and is the most precise determination using the coupling of the Z/γ^{*} to light quarks.

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of sqrt[s]=1.96  TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is A_{FB}^{tt[over ¯]}=0.128±0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.

Evidence for a B_{s}^{0}π^{±} State

We report evidence for a narrow structure, X(5568), in the decay sequence X(5568)→B_{s}^{0}π^{±}, B_{s}^{0}→J/ψϕ, J/ψ→μ^{+}μ^{-}, ϕ→K^{+}K^{-}. This is evidence for the first instance of a hadronic state with valence quarks of four different flavors. The mass and natural width of this state are measured to be m=5567.8±2.9(stat)_{-1.9}^{+0.9}(syst)  MeV/c^{2} and Γ=21.9±6.4(stat)_{-2.5}^{+5.0}(syst)  MeV/c^{2}. If the decay is X(5568)→B_{s}^{*}π^{±}→B_{s}^{0}γπ^{±} with an unseen γ, m(X(5568)) will be shifted up by m(B_{s}^{*})-m(B_{s}^{0})∼49  MeV/c^{2}. This measurement is based on 10.4  fb^{-1} of pp[over ¯] collision data at sqrt[s]=1.96  TeV collected by the D0 experiment at the Fermilab Tevatron collider.

Influence of temperature on reproductive biology and phenotype of a ladybird, Menochilus sexmaculatus (Fabricius) (Coleoptera: Coccinellidae)

Body melanisation in insects is polygenic, resulting from genetic polymorphism or phenotypic plasticity, with diverse implications ranging from thermal budgeting to reproductive success. In this study, we assessed the, mate choice, reproductive success, and offspring colouration of typical (T) and melanic (M) morphs of the ladybird Menochilus sexmaculatus paired at three temperatures 15°C, 25°C and 35°C. Mating success of the two morphs and the consequences for offspring fitness and offspring phenotype under these temperature regimes were evaluated. Melanic adults of both sexes achieved significantly higher mating success at 15°C and 25°C, but at 35°C no influence of adult morph on mate selection was observed. Melanic females were more fecund than typical females at all temperatures. Offspring of melanic parents developed faster than those of typicals at 15°C and 25°C, but not at 35°C. Evidence was also found of phenotypic plasticity in colour form at 15°C and 35°C. At 25°C the parents of pure (T) and (M) morphs produced offspring of the same morph. However, low temperature induced partial melanisation among the offspring of typical parents (T). Whereas at 35°C the offspring of (T) parents became paler in colour with very fine zigzag lines on elytra, i.e. they decrease the degree of melanisation. Pure melanics (M) compensated for elevated temperature stress by producing offspring that were either pure melanic but small or large with reduced melanisation. Our results on offspring phenotype variation indicate that the degree of melanism in morphs is a result of environmentally regulated expression of the parental genotype.

Evidence for Simultaneous Production of J/ψ and ϒ Mesons

We report evidence for the simultaneous production of J/ψ and ϒ mesons in 8.1  fb^{-1} of data collected at sqrt[s]=1.96  TeV by the D0 experiment at the Fermilab pp[over ¯] Tevatron Collider. Events with these characteristics are expected to be produced predominantly by gluon-gluon interactions. In this analysis, we extract the effective cross section characterizing the initial parton spatial distribution, σ_{eff}=2.2±0.7(stat)±0.9(syst)  mb.

Inclusive Production of the X(4140) State in pp[over ¯] Collisions at D0

We present a study of the inclusive production of the X(4140) state with the decay to the J/ψϕ final state in hadronic collisions. Based on 10.4  fb^{-1} of pp[over ¯] collision data collected by the D0 experiment at the Fermilab Tevatron collider, we report the first evidence for the prompt production of an X(4140) state and find the fraction of X(4140) events originating from b hadrons to be f_{b}=0.39±0.07(stat)±0.10(syst). The ratio of the nonprompt X(4140) production rate to the B_{s}^{0} yield in the same channel is R=0.19±0.05(stat)±0.07(syst). The values of the mass M=4152.5±1.7(stat)_{-5.4}^{+6.2}(syst)  MeV and width Γ=16.3±5.6(stat)±11.4(syst)  MeV are consistent with previous measurements.

Search for Violation of CPT and Lorentz Invariance in Bs(0) Meson Oscillations

We present the first search for CPT-violating effects in the mixing of Bs(0) mesons using the full Run II data set with an integrated luminosity of 10.4  fb(-1) of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. We measure the CPT-violating asymmetry in the decay Bs(0)→μ(±)Ds(±) as a function of celestial direction and sidereal phase. We find no evidence for CPT-violating effects and place limits on the direction and magnitude of flavor-dependent CPT- and Lorentz-invariance violating coupling coefficients. We find 95% confidence intervals of Δa⊥<1.2×10(-12)  GeV and (-0.8<ΔaT-0.396ΔaZ<3.9)×10(-13)  GeV.

Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element V_{tb}

We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb^{-1} per experiment. The t-channel cross section is measured to be σ_{t}=2.25_{-0.31}^{+0.29} pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in σ_{s+t}=3.30_{-0.40}^{+0.52} pb, without assuming the standard model value for the ratio σ_{s}/σ_{t}. The resulting value of the magnitude of the top-to-bottom quark coupling is |V_{tb}|=1.02_{-0.05}^{+0.06}, corresponding to |V_{tb}|>0.92 at the 95% C.L.

Measurement of the Effective Weak Mixing Angle in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} Events

We present a measurement of the fundamental parameter of the standard model, the weak mixing angle sin^{2}θ_{eff}^{ℓ} which determines the relative strength of weak and electromagnetic interactions, in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} events at a center of mass energy of 1.96 TeV, using data corresponding to 9.7 fb^{-1} of integrated luminosity collected by the D0 detector at the Fermilab Tevatron. The effective weak mixing angle is extracted from the forward-backward charge asymmetry as a function of the invariant mass around the Z boson pole. The measured value of sin^{2}θ_{eff}^{ℓ}=0.23147±0.00047 is the most precise measurement from light quark interactions to date, with a precision close to the best LEP and SLD results.