Demonstrating Agreement between Radio and Fluorescence Measurements of the Depth of Maximum of Extensive Air Showers at the Pierre Auger Observatory

We show, for the first time, radio measurements of the depth of shower maximum (X_{max}) of air showers induced by cosmic rays that are compared to measurements of the established fluorescence method at the same location. Using measurements at the Pierre Auger Observatory we show full compatibility between our radio and the previously published fluorescence dataset, and between a subset of air showers observed simultaneously with both radio and fluorescence techniques, a measurement setup unique to the Pierre Auger Observatory. Furthermore, we show radio X_{max} resolution as a function of energy and demonstrate the ability to make competitive high-resolution X_{max} measurements with even a sparse radio array. With this, we show that the radio technique is capable of cosmic-ray mass composition studies, both at Auger and at other experiments.

Pathway Mutations are Associated with Clinical Outcomes in Localized Pancreatic Cancer Treated with Neoadjuvant Chemoradiation Followed by Surgery

PURPOSE/OBJECTIVE(S)

The purpose of this study was to determine if mutations in biological pathways are associated with clinical outcomes in patients with localized pancreatic cancer who undergo neoadjuvant chemoradiation followed by surgical resection.

MATERIALS/METHODS

Patients treated with neoadjuvant chemoradiation followed by oncologic resection from 2015-2019 who also underwent next generation sequencing (NGS) of the primary tumor were included in this retrospective analysis. NGS was done using either Foundation One (n = 20), in-house Solid Tumor Panel (n = 121), or Tempus XT (n = 1). Genes were included in pathway analysis if at least one patient harbored a mutation in the gene. Pathways were defined from the Molecular Signatures Database Hallmark, KEGG, and Reactome gene sets. A pathway was deemed mutated if at least one gene within the pathway was mutated. Univariable Cox regression was performed to determine the association between pathway mutation status and overall survival (OS) as well as progression-free survival (PFS).

RESULTS

In total, 142 patients met criteria for study inclusion. For pathway analysis, 329 genes met inclusion criteria. Patients were typically treated with neoadjuvant chemotherapy (either 5-fluorouracil-based or gemcitabine-based) followed by radiation. Patients received SBRT (n = 104, most commonly 33 Gy in 5 fractions) or conventionally fractionated radiation (n = 38, most commonly 50.4 Gy in 28 fractions). For clinical variables, worse OS was significantly associated with T stage (p = 0.036), N stage (p = 0.044), and lymphovascular invasion (LVI, p = 0.011); worse PFS was significantly associated with T stage (p = 0.0008), N stage (p = 0.022), LVI (p = 0.026), and conventional RT (p = 0.007). Mutations in major pathways were associated with worse OS, notably hedgehog signaling (p = 0.001), chromatin modifying enzymes (p = 0.002), WNT/beta-catenin signaling (p = 0.005), mismatch repair (0.006), E2F targets (p = 0.008), FLT signaling (p = 0.012), VEGF signaling (0.025), innate immune system (p = 0.026), and NOTCH signaling (p = 0.029). Pathway mutations associated with worse PFS included mismatch repair (p = 0.007) and hedgehog signaling (p = 0.013).

CONCLUSION

For pancreatic cancer patients that undergo neoadjuvant chemoradiation followed by oncologic resection of the primary tumor, mutations in key biological pathways are associated with OS and PFS. Characterizing the importance of common pathway mutations may become increasingly valuable to help categorize less commonly mutated genes assayed by NGS.

Characterization of DNA Damage Response-Associated Somatic Mutations in Borderline Resectable and Locally Advanced Pancreatic Cancer

PURPOSE/OBJECTIVE(S)

The role of radiation for pancreatic cancer remains controversial, with recent studies showing conflicting results, highlighting the need to develop biomarkers of radiation response. Despite its potential utility in predicting radiosensitivity, the landscape of somatic mutations in borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC), as related to DNA damage response (DDR), has not been well characterized. This study aimed to characterize the frequency of such mutations in a cohort of patients with BRPC/LAPC treated with neoadjuvant chemotherapy and stereotactic body radiotherapy (SBRT).

MATERIALS/METHODS

Mutational data was collected from patients with BRPC/LAPC treated at a single institution with neoadjuvant chemotherapy and SBRT, followed by surgical resection from 2016-2021. Chemotherapy consisted of modified FOLFIRINOX or gemcitabine/nab-paclitaxel, and patients were treated with SBRT in 33 Gy in 5 fractions. Genomic data was obtained from either endoscopic biopsy or surgical specimens, and next-generation sequencing was performed either in-house with a Solid Tumor Panel or with FoundationOne CDx. Specific emphasis was placed on the characterization of double-strand DNA break (DSB) repair genes, as this is the type of tumor cell damage traditionally induced by radiation therapy. Genes associated with the two main pathways of DSB repair, non-homologous end joining (NHEJ) and homologous repair (HR), were analyzed. Specific HR pathway mutations assessed were BLM, BRCA1/2, MRE11, NBN, PALB2, RAD50, RAD51B-D, and RAD54L, while PRKDC mutations were assessed for the NHEJ pathway. Mutations in ATM, an important initiator of DDR pathways, were also analyzed. Additionally, the frequency of mutations in TP53, CDKN2A and SMAD4 in patients with concomitant KRAS mutations was assessed.

RESULTS

Eighty-five patients were included in the study. Five (5.9%) patients had mutations in the NHEJ pathway of the PRKDC gene. Twenty (23.5%) patients had mutations in the HR pathway, including BRCA2 (10/85; 11.8%), PALB2 (5/85; 5.9%), BRCA1 (3/85; 3.5%), and RAD50 (1/85; 1.2%). Six (7.1%) patients had mutations in ATM. No patients were found to have mutations in BLM, RAD51B-D, RAD54L, or NBN. Amongst patients with KRAS mutations (72/85), concomitant mutations were observed in TP53 (47/85; 55.3%), CDKN2A (16/85; 18.8%), and SMAD4 (9/85; 10.6%).

CONCLUSION

Herein, we characterized the frequency of somatic mutations associated with DSB repair genes in patients with BRPC/LAPC. Data analysis on outcomes related to radiation response in patients with mutations in DDR pathways is ongoing, but will likely also benefit from multi-institutional efforts to increase the power to answer this question.

Utilization of the Triangle Volume in Patients with Localized PDAC Undergoing Pre-Operative SBRT: Report of Early Outcomes

PURPOSE/OBJECTIVE(S)

In patients with borderline resectable or locally advanced pancreatic adenocarcinoma (BRPC/LAPC), advances in neoadjuvant therapy have led to an increased proportion of patients undergoing margin negative resection. Nevertheless, locoregional recurrence rates remain high. We have previously reported that the location of locoregional recurrences in this setting map to the "Triangle Volume (TV)," the anatomical space between the celiac artery, superior mesenteric artery, common hepatic artery, and portal vein, which is enriched in extrapancreatic perineural tracts at risk for microscopic residual disease after resection. At the beginning of 2021, we systematically changed our target volume to include the TV, in addition to gross disease and involved vasculature. Herein, we report early locoregional failure outcomes after resection in the setting of BRPC or LAPC treated with pre-operative stereotactic body radiation therapy (SBRT) to the TV, as compared to historical rates.

MATERIALS/METHODS

Patients who received a diagnosis of BRPC or LAPC and who were treated at our institution with neoadjuvant chemotherapy (CTX) and SBRT between 2016 and 2022 were retrospectively reviewed. Between 2016 and 2020, the SBRT clinical tumor volume (CTV) included gross disease and full circumference of involved vasculature at the level of involvement. From 2021 onward, the CTV also included the TV. Survival was estimated using the Kaplan-Meier method. Statistical analyses were performed using scientific 2-D graphing and statistics software.

RESULTS

From January 2016 to December 2022, 204 patients with localized PDAC underwent neoadjuvant CTX followed by SBRT. After completion of SBRT, all patients proceeded with surgical exploration. Of these patients, 111 (54%) had LAPC and 92 (45%) had BRPC disease. All patients were treated with induction CTX, mostly commonly with FOLFIRINOX (N = 166, 81%). Following CTX, the most frequently used SBRT regimen was 33 Gy in 5 fractions (N = 191, 94%). 155 (67%) patients were treated between 2016 and 2020 to the traditional CTV, while 49 (24%) patients were treated after 2020 to a CTV that included the TV. The 2-year local progression free survival rate of patients treated with SBRT using the TV was 77.6% as compared to 47.5% in patients treated with the traditional CTV. Over a median follow up of 15.7 months (range: 1 to 78.2 months), 47% (N = 73 out of 155) of patients who underwent SBRT with the traditional CTV developed locoregional recurrence, but only 12% (N = 6 out of 49) treated with SBRT to the TV have thus far developed locoregional recurrence (p<0.0001).

CONCLUSION

In patients with localized PDAC who undergo pre-operative SBRT for BRPC/LAPC, targeting the TV may help reduce locoregional recurrence. More data and longer follow-up are needed to verify these findings and inform whether the TV may serve as a new standard for target volume delineation in this setting.

Visceral Artery Pseudoaneurysm Rates after Pancreatoduodenectomy in Patients Who Received Pre-Operative Radiation for Pancreatic Cancer

PURPOSE/OBJECTIVE(S)

The role of pre-operative radiation therapy (RT) for localized pancreatic ductal adenocarcinoma (PDAC) with peri-pancreatic vascular involvement remains controversial, with two recent randomized controlled trials, namely PREOPANC-1 and Alliance A021501, showing conflicting results. Opponents of pre-operative radiation point towards the unclear oncologic benefit and potential added toxicity. While hemorrhage from a pseudoaneurysm (PsA) rupture is a known rare but potentially fatal complication after pancreaticoduodenectomy (PD), with published incidence rates of around 2 to 5%, it has been increasingly common in the pancreatic cancer surgical community for pre-operative RT to be cited as a risk factor for PsA development, despite the absence of data supporting this notion. Certainly, accurate characterization of relevant RT-related toxicities is critical to prevent inaccurate decision-making regarding foregoing its use. As such, we aim to report on the incidence of PsA in a cohort of patients with PDAC who underwent pre-operative RT prior to PD at a high-volume center.

MATERIALS/METHODS

Consecutive patients treated with pre-operative RT via stereotactic body radiation therapy (SBRT) or intensity modulated radiation therapy (IMRT) prior to PD for borderline resectable or locally advanced PDAC were retrospectively reviewed. Incidence of radiographic or clinically apparent PsA was reported. We also characterized the timing of PsA identification in relation to surgery and RT, the artery in which the PsA developed, and the clinical outcomes of patients after PsA identification.

RESULTS

One hundred seventy-five patients met eligibility criteria for our analysis. Most of our cohort (163 patients, 93%) received SBRT to a median dose of 6.6 Gy x 5 (median BED10 54.78 Gy, range: 48 Gy - 61.92 Gy), and only 12 patients (7%) received IMRT in various fractionation and dose patterns (median BED10 62.94 Gy, range 59.47 Gy - 97.5 Gy). The median time between surgery and last contrast-enhanced abdominal imaging was 17 months (range: 0.23 - 68 months). There were fourteen visceral arteries among thirteen patients (7%) that were found to have a PsA on routine follow-up imaging or after a post-PD hemorrhage. The median time between completion of radiation and surgery to PsA were 19.5 weeks (range: 8.6 to 98.1 weeks) and 13 weeks (range: 1.6 to 87.9 weeks), respectively. The two most commonly involved arteries were the gastroduodenal and superior mesenteric arteries. Rate of PsA development was similar among patients treated with SBRT (7%) and IMRT (8%). In terms of Clavien-Dindo classification of complications, there were six patients with grade 3a complications, five patients with grade 4b complications, and two patients with grade 5 complications.

CONCLUSION

Compared to historical data, pre-operative RT does not appear to significantly increase the risk of PsA development after PD. More data on the impact of pre-operative radiation dose-fraction regimen and longer follow-up are needed.

The clinical relevance of human papillomavirus negative status in unsatisfactory cervical cytology

PURPOSE

The aim of this study was to evaluate the clinical relevance of high-risk human papillomavirus (HR-HPV) negativity at the time of unsatisfactory cervical cytology.

METHODS

In this retrospective observational study, records were reviewed for patients who had unsatisfactory cervical cytology with HR-HPV testing performed from January 2015 through September 2019 at a large teaching hospital. Pathology results of follow-up cervical cytology and biopsies were assessed.

RESULTS

Of 1282 patients with unsatisfactory cervical cytology and negative HR-HPV testing, repeat cytology was negative for intraepithelial lesion (NIL) in 952 (75%) patients, unsatisfactory in 273 (22%) patients, and abnormal in 41 (3%) patients. Median follow-up time was 91 days. The concordance of HR-HPV status between initial unsatisfactory cervical cytology and subsequent satisfactory cervical cytology was 96.3% for HR-HPV negative patients and 68.8% for HR-HPV positive patients. Compared to women who were HR-HPV negative, women who were HR-HPV positive on initial unsatisfactory cytology were at higher risk of subsequent cervical intraepithelial neoplasia (CIN) 2 or greater (odds ratio = 4.91, 95% confidence interval: 1.34-18.03 for E6/E7 mRNA positivity alone; odds ratio = 46.13, 95% confidence interval: 13.45-158.01 for HR-HPV genotype 16 or 18/45 positivity).

CONCLUSION

In the 3 month follow-up of patients with unsatisfactory cervical cytology and negative HR-HPV testing, approximately 3% had abnormal cytology but no cases of HPV related pathology of CIN 2 or greater were found. There was high concordance of negative HR-HPV testing results with those on follow-up satisfactory cervical cytology.

Limits to Gauge Coupling in the Dark Sector Set by the Nonobservation of Instanton-Induced Decay of Super-Heavy Dark Matter in the Pierre Auger Observatory Data

Instantons, which are nonperturbative solutions to Yang-Mills equations, provide a signal for the occurrence of quantum tunneling between distinct classes of vacua. They can give rise to decays of particles otherwise forbidden. Using data collected at the Pierre Auger Observatory, we search for signatures of such instanton-induced processes that would be suggestive of super-heavy particles decaying in the Galactic halo. These particles could have been produced during the post-inflationary epoch and match the relic abundance of dark matter inferred today. The nonobservation of the signatures searched for allows us to derive a bound on the reduced coupling constant of gauge interactions in the dark sector: α_{X}≲0.09, for 10^{9}≲M_{X}/GeV<10^{19}. Conversely, we obtain that, for instance, a reduced coupling constant α_{X}=0.09 excludes masses M_{X}≳3×10^{13}  GeV. In the context of dark matter production from gravitational interactions alone, we illustrate how these bounds are complementary to those obtained on the Hubble rate at the end of inflation from the nonobservation of tensor modes in the cosmological microwave background.

Efficacy and Safety of Reirradiation with Stereotactic Body Radiation Therapy for Locally Recurrent Pancreatic Adenocarcinoma

AIMS

The purpose of this study was to report on outcomes of a cohort of patients who were treated with reirradiation with stereotactic body radiation therapy (SBRT) for locally recurrent pancreatic adenocarcinoma.

MATERIALS AND METHODS

Patients treated with SBRT reirradiation for locally recurrent pancreatic adenocarcinoma from December 2009 to April 2020 were included in the study. Descriptive statistics were used to record patient demographics, tumour and treatment characteristics. Kaplan-Meier analysis was used to evaluate overall survival, local progression-free survival (LPFS), distant metastasis-free survival and progression-free survival (PFS).

RESULTS

In total, 27 patients were included in the study. The median follow-up time from local recurrence was 19.7 months (range 4.2-43.1 months). Most patients received five-fraction SBRT (26/27, 96%). The median overall survival after local recurrence treatment was 18.3 months (range 3.0-42.6 months), with 6-month, 1-year and 2-year overall survival rates of 88.5%, 73.1% and 33.6%. The median LPFS after local recurrence treatment was 16.2 months (range 2.3-33.6 months), with 6-month, 1-year and 2-year LPFS rates of 95.8%, 62.9% and 27.2%. Peri-SBRT chemotherapy improved LPFS (median 17.5 versus 8.5 months; P = 0.010) and overall survival (median 19.3 versus 5.5 months; P = 0.049). Tumours ≤ 3 cm in the greatest dimension showed better local control (median LPFS 19.2 versus 10.2 months; P = 0.130). There was one case (4%) of acute grade 3 pain and one case (4%) of late grade 3 gastrointestinal toxicity.

CONCLUSIONS

Reirradiation with five-fraction SBRT is safe, but local control remains suboptimal. Patients with smaller tumours experienced improved outcomes, as did patients whose treatment plan included the administration of peri-SBRT chemotherapy.

302 Migratory Foreign Body in The Neck- How A Fishbone Morphed into A Piece of Glass In 18 Months

Background

Foreign body (FB) ingestion is a common presentation to ear, nose, and throat (ENT) surgeons. Usual culprits include fish or chicken bones, steak, or non-organic items. FBs can be categorised into batteries, hard objects, and soft boluses. Hard objects that have not passed beyond the post-cricoid region require removal to minimise perforation risk. In rare cases FBs are reported to migrate extra-luminally into surrounding tissues of the neck necessitating cross-sectional imaging ahead of neck exploration.

Case Report

A 70-year-old lady presented to A&E with a sensation of FBs in her throat. She was aphagic without dyspnoea. Home-cooked fish ingestion was the precursor. Panendoscopy was clear. The patient was discharged once tolerating fluids and soft diet. She presented 14 months later to the ENT clinic with a persistent FB sensation in her throat. A computed-tomography scan of neck showed a right sided, radio-opaque, 3 cm foreign body sitting just anterior to the carotid sheath, behind the right superior thyroid lobe. An elective external neck exploration revealed a 3 cm shard of glass which was successfully removed without complications.

Conclusions

Extra-luminal migration of FBs is extremely rare. They may present with life-threatening suppurative or vascular complications. A literature review revealed that migratory FBs tend to be sharp and long such as needles, wires, or fishbones. To allow prompt diagnosis and management, we propose a low threshold for CT imaging in instances with a clear history and persistent symptoms even when panendoscopy is negative.

Clinical course and surgical outcomes in middle-age adults with anomalous aortic origin of a coronary artery

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with anomalous aortic origin of a coronary artery (AAOCA) present with a wide range of clinical manifestations, including ischemic symptoms (chest pain or dyspnea) and sudden cardiac death (SCD). Studies have identified coronary anatomic characteristics associated with a higher risk of SCD. However, most of the published literature consists of studies in adolescents and young adults. There is a paucity of data regarding outcomes in middle-aged patients. Current guidelines reveal gaps in evidence for identification of adults are at risk for SCD, and for whom surgery is beneficial.

Purpose

To study the clinical course and rate of major adverse cardiac events (MACE) in middle-aged adults with AAOCA based on presenting symptoms, coronary anatomy on coronary computed tomography angiography (CCTA), stress test results, and surgical management.

Methods

We included all patients from January 2013 to December 2019 age &gt; 18 at our institution who were found to have AAOCA.  Patients with the following were excluded to minimize confounding factors which could cause MACE: coronary artery disease (CAD) with &gt;50% stenosis in any coronary vessel, CAD requiring revascularization, heart failure with ejection fraction &lt;40%, history of heart transplant, and non-AAOCA congenital heart disease. All patient charts were reviewed for demographics, coronary anatomy on CCTA, presenting symptoms, rationale for pursuing stress testing and CCTA, nature of surgical interventions, post-surgical course, and MACE (cardiovascular death, myocardial infarction, and need for coronary revascularization). All patients underwent PET as well as treadmill stress testing.

Results

Of 19,367 patients who underwent CCTA, 47 met inclusion criteria, with median age at diagnosis of 54 and median follow-up of 48 months. No patients suffered MACE. Twenty-five patients had AAORCA and 22 had AAOLCA (Table 1). Ten patients with AAORCA and 8 patients with AAOLCA presented with ischemic symptoms and had coronary anatomy characteristics associated with higher risk of SCD, as well as ischemia corresponding to the anomalous artery on stress testing and did not undergo surgery due to personal preference. Five symptomatic patients with stress-induced ischemia corresponding to the anomalous artery underwent surgery and all achieved symptom relief over a median follow up of 5 years.

Conclusion

As AAOCA is a significant cause of SCD in young adults, it is compelling to observe this adult cohort in which no patients experienced MACE, including 18 symptomatic patients with high-risk anatomy and stress-induced ischemia, as well as a Class I recommendations for surgery.  The results suggest that although surgery may be beneficial for symptom relief, it does not necessarily improve mortality over an intermediate follow-up period.  Future studies should examine surgical outcomes in middle-aged cohorts with larger sample sizes.

A Multicenter Prospective Registry Study of Lung Transplant Recipients Hospitalized with COVID-19

Purpose

Outcomes of lung transplant recipients (LTR) hospitalized for COVID-19 and comparisons to non-lung solid organ transplant recipients (SOTR) are incompletely described.

Methods

Using a multicenter prospective registry of SOTR, we examined 28-day outcomes (mortality [primary outcome], intensive care unit (ICU) admission, mechanical ventilation, and bacterial pneumonia) among both LTR and non-lung SOTR hospitalized with laboratory-confirmed COVID-19 diagnosed between March 1, 2020 and September 21, 2020. Data were analyzed using Stata (StataCorp, College Station, TX); chi-square tests were used to compare categorical variables and multivariable logistic regression was used to assess risk factors for mortality.

Results

The cohort included 72 LTR and 392 non-lung SOTR (Table 1). Overall, 28-day mortality trended higher in LTR vs. non-lung SOTR (27.8% vs. 19.9%, P=0.136). Other 28-day outcomes were similar between LTR and non-lung SOTR: ICU admission (45.8% vs. 39.1%, P=0.28), mechanical ventilation (32.9% vs. 31.1%, P=0.78), and bacterial pneumonia (15.3% vs. 8.2%, P=0.063). Congestive heart failure, diabetes, age >65 years, and obesity (BMI >= 30) were independently associated with mortality in non-lung SOTR, but not in LTR (Table 2).

Conclusion

In this large prospective cohort comparing lung and non-lung SOTR hospitalized for COVID-19, there were high but not significantly different rates of short-term morbidity and mortality. Baseline comorbidities appeared to drive mortality in non-lung SOTR but not LTR. Further studies are needed to identify risk factors for mortality among LTR.

CTA Evaluation of Basilar Septations: An Entity Better Characterized as Aberrant Basilar Fenestrations

BACKGROUND AND PURPOSE

A basilar artery intraluminal septation is an exceedingly rarely reported, presumed congenital abnormality. In our clinical practice, we have occasionally noticed an intraluminal band within the inferior aspect of the basilar artery on CTA. Furthermore, we have noticed, at times, the presence of a punctate calcification associated with this finding. We hypothesized that what previous studies have called "basilar septations" in fact represent miniature and thus aberrant basilar fenestrations.

MATERIALS AND METHODS

We retrospectively reviewed CTA studies obtained between January 1, 2017, and August 31, 2019. Identified intraluminal basilar abnormalities were classified as either basilar septations or basilar fenestrations. Association with other posterior circulation abnormalities was documented.

RESULTS

A total of 3509 studies were examined. A basilar intraluminal abnormality was evident in 80 patients (2.3%). Of these 80 patients, 59 were classified as having a basilar fenestration (1.7%) and 21 were classified as having basilar septations (0.6%). Associated calcification was evident in 3 of the basilar fenestration cases and 13 of the basilar septation cases.

CONCLUSIONS

Basilar septations most likely represent and should be referred to as aberrant basilar fenestrations. They should be interpreted as benign congenital incidental findings and should not be misinterpreted as focal dissections or arterial webs. Important variations in the morphology of aberrant basilar fenestrations exist, including areas of thinning, varying thickness, and nodularity. Therefore, when associated with calcification or nodularity, aberrant basilar fenestrations should not be confused with focal intraluminal thrombi or calcified or noncalcified emboli.

ADENOID CYSTIC CARCINOMA MISINTERPRETED AS ANTROCHOANAL POLYP: A RARE PRESENTATION

Adenoid cystic Carcnoma (ACC) is an uncommon malignant tumour accounting for <1% of all oral and maxillofacial tumors. However, in the sinonasal tract, ACC is the most common salivary gland tumor. The sinonasal ACC is asymptomatic initially or causes non-specific symptoms that are similar to those caused by inflammatory sinus disease and local neurological symptoms such as trigeminal neuralgia in advance stage due to perineural invasion by the tumour.We present a case of 35-year-old female who presented with complaints of nasal obstruction and headache. CT scans revealed an antrochoanal polyp without any bony involvement. The histopathological examination revealed unremarkable respiratory epithelium with underlying sheets and acini of small hyperchromatic cells with hyaline-like material in the lumina, confirming adenoid cystic carcinoma. The highlight of this case is that sinonasal polyps are not always inflammatory in origin, these can be neoplastic also.

Numerical analysis of subcritical Hopf bifurcations in the two-dimensional FitzHugh-Nagumo model

It had been shown that the transition from a rigidly rotating spiral wave to a meandering spiral wave is via a Hopf bifurcation. Many studies have shown that these bifurcations are supercritical, but, by using simulations in a comoving frame of reference, we present numerical results which show that subcritical bifurcations are also present within FitzHugh-Nagumo. We show that a hysteresis region is present at the boundary of the rigidly rotating spiral waves and the meandering spiral waves for a particular set of parameters, a feature of FitzHugh-Nagumo that has previously not been reported. Furthermore, we present a evidence that this bifurcation is highly sensitive to initial conditions, and it is possible to convert one solution in the hysteresis loop to the other.

Anaemia and thyrotoxicosis: The need to look for an alternative cause

OBJECTIVES

Anaemia and thyrotoxicosis are both relatively common. It is unclear whether thyrotoxicosis results in anaemia in the absence of other causes. The aim of this study was to determine the prevalence and characteristics of anaemia in patients with thyrotoxicosis.

DESIGN

A prospective cohort study of patients with thyrotoxicosis.

PATIENTS

353 patients referred to a regional endocrinology centre in New Zealand from March 2013 to November 2014 for new-onset thyrotoxicosis.

MEASUREMENTS

Detailed assessment including thyroid function tests, full blood count, inflammatory markers, haematological parameters and coeliac serology. Anaemia was defined as a haemoglobin value <115 g/L (woman) or <130 g/L (men).

RESULTS

Anaemia was present in 31 (8.7%) patients at diagnosis. Of these, pre-existing anaemia was present in 10, and a further 11 had one or more identifiable underlying cause(s) for the anaemia. Only 10 patients (2.8% of the entire cohort) had anaemia not clearly attributable to another cause. Median free thyroid hormone levels were higher in those with anaemia of unknown cause compared to patients with thyrotoxicosis alone. The median duration of anaemia was shorter in patients with thyrotoxicosis-associated anaemia compared to those with anaemia due to an underlying cause (1 vs 6 months, P = .001). In all patients with thyrotoxicosis-associated anaemia, the anaemia resolved, either prior to, or on becoming euthyroid.

CONCLUSION

Anaemia coexisting with thyrotoxicosis is less common than previously reported and is mild and transient. Patients with thyrotoxicosis and significant anaemia should be investigated for other potential causes, particularly when anaemia persists.

Cytological Diagnosis of Primary Thyroid Tuberculosis

Primary thyroid tuberculosis is an extremely rare disease, even in countries where other forms of tuberculosis are abundant. TT has no age bar but usually affects women in fourth and fifth decade. Hereby, we report a case of 16-years-old girl presented with complaint of progressively increasing, painful thyroid swelling. Diagnosis of TT was made on cytology and there was no evidence of involvement of any other organ by tuberculosis. Despite of its rarity, TT is usually misdiagnosed. So, a clinician should always consider this entity in the differential diagnosis of thyroid swelling. Fine needle aspiration cytology is the best diagnostic method and can result in the avoidance of unnecessary thyroid surgeries.

Nutritional composition of ginger powder prepared using various drying methods

A study was undertaken to prepare ginger powder using various drying methods and their nutritional evaluation was carried out. Ginger (Zingiber officinale) was dried using shade, solar, oven and microwave drying methods. All the samples were ground in grinder to make fine powder. Sensory analysis indicated that acceptability of all types of ginger powders were in the range of 'liked very much' to 'liked moderately' by the panelists. The mean score obtained for colour was higher in shade dried ginger powder i.e., 8.20 as compared to oven dried (7.60), solar dried (7.70) and microwave dried ginger powder (7.80). Moisture content ranged from 3.55 % in solar dried ginger powder to 3.78 % in shade dried ginger powder. Slightly higher moisture content was found in shade dried ginger powder. Protein, crude fiber, fat and ash contents ranged from 5.02 to 5.82, 4.97 to 5.61, 0.76 to 0.90 and 3.38 to 3.66 %, respectively. β-carotene and ascorbic acid content was found maximum in shade dried ginger powder i.e., 0.81 mg/100 g and 3.83 mg/100 g, respectively. Polyphenol content was almost similar in all the samples whereas calcium was slightly higher in the shade dried ginger powder i.e., 69.21 mg/100 g. Results have shown that ginger powder prepared from various drying methods had good sensory and nutritional profile.

Relevance of opt-out screening for HIV in emergency and pre-surgery patients in a tertiary care center in Northern India: a pilot study

OBJECTIVE

A preliminary opt-out screening study for HIV was conducted in a tertiary care hospital in India according to Center for Disease Control (CDC) guidelines. A total of 876 cases were screened for HIV during August 2007 to December 2007 using tests approved by the National AIDS Control Organization (NACO).

RESULTS

Data indicates that the prevalence of HIV in emergency and pre-surgical setting was 21 per thousand at the tertiary care center. Positivity rate in the pediatric population was 20.9 per thousand while in adults it was 21.4 per thousand. Most patients were totally unsuspected. Nearly 40000 patients seek admission annually to the emergency department alone. Thus nearly 700 to 800 patients may be missed every year if one does not resort to such a practice.

CONCLUSION

Since India has the second largest number of HIV cases in the world, opt-out screening program and testing in an emergency setting, as recommended by CDC, is extremely relevant. Logistics of implementation of this policy need to be worked out at a national level.

High incidence of Epstein Barr virus infection in childhood acute lymphocytic leukemia: a preliminary study

INTRODUCTION

Epstein Barr virus (EBV) has a unique association with several human malignancies, especially lymphoproliferative disorders, mainly lymphomas in adults. There is paucity of data pertaining to EBV association with various cancers in India .

OBJECTIVE

The study aims to investigate the association of EBV in childhood leukemia.

MATERIAL AND METHODS

Patients attending pediatric oncology services of the referral center have been included in the study. Twenty-five consecutive pediatric patients with acute lymphocytic lukemia (ALL) were subjected to EBV studies employing sensitive polymerase chain reaction followed by hybridization for presence of Bam H1-W region of EBV genome and detection of anti Z EBV replication activator (ZEBRA) antibodies using Western blot. Positive control included a case of Burkitt's lymphoma and infectious mononucleosis each. Raji cells were used as positive control with each test.

RESULTS

The PCR for EBV was positive in 8/25 patients of ALL. Western blot test using anti ZEBRA antibodies was positive in 5/25(20%) cases of ALL. Considering PCR as the gold standard, 32% of the children with ALL had evidence of active EBV replication. The positive controls were consistently positive. None of the 30 healthy laboratory controls, 22 age matched disease controls, 12 cases of AML and 15 cases of multiple myeloma were positive either by PCR or Western blots assays (P < 0. 01). There was no statistically significant correlation between duration of therapy and EBV positivity (P > 0.05).

CONCLUSION

These studies indicate that a significant number of patients with ALL show evidence of active EBV replication.

A single dose of preoperative gabapentin for pain reduction and requirement of morphine after total mastectomy and axillary dissection: randomized placebo-controlled double-blind trial

BACKGROUND

Gabapentin has been recently found to be useful for reducing acute postoperative pain when administered preoperatively. Although various dose regimens have been tried in different surgical settings, the minimum effective dose is not established.

AIMS

We aimed to evaluate the analgesic efficacy of single low dose gabapentin in patients undergoing total mastectomy and axillary dissection.

SETTINGS AND DESIGN

Prospective randomized placebo-controlled double-blind trial in a tertiary care teaching hospital.

MATERIALS AND METHODS

Fifty women scheduled for total mastectomy and axillary dissection were randomized to receive either gabapentin 600 mg or placebo orally 1 h preoperatively. The intraoperative and postoperative management was standardized. Postoperative pain was assessed at rest and on movement for 12 h using the numerical rating scale (NRS). Morphine was administered if NRS exceeded 30. Primary outcome measure was total morphine consumption.

STATISTICAL ANALYSIS

The morphine consumption was compared using independent t test while pain and sedation scores were analyzed using Mann-Whitney U test.

RESULTS

Forty-six patients completed the trial. The postoperative morphine consumption was significantly less (5.8 +/- 4.2 vs. 11.0 +/- 3.4 mg; P 0.001) and the median [IQR] time to first analgesic was significantly longer (90 [37.5-120] vs. 0 [0-90] min; P 0.001) in the gabapentin group than in the placebo group. The incidence of side effects was similar in the two groups.

CONCLUSIONS

A single low dose of 600 mg gabapentin administered 1 h prior to surgery produced effective and significant postoperative analgesia after total mastectomy and axillary dissection without significant side effects.

High rate of mutation K103N causing resistance to nevirapine in Indian children with acquired immunodeficiency syndrome

In north India the number of paediatric cases with acquired immunodeficiency syndrome (AIDS) is on the rise. Most drug combinations used for treatment of AIDS incorporate nevirapine, resistance to which develops very fast if given singly or because of unplanned interruptions. This paper investigates presence of mutations at codon 103 and codon 215 of the HIV pol gene causing resistance to nevirapine and zidovudine (AZT) respectively in 25 children with AIDS. Mutations T215Y and K103N were detected by a nested cum amplification refractory mutation system polymerase chain reaction (ARMS PCR) and the results were confirmed by direct sequencing in five randomly selected cases. Nineteen patients had received nevirapine containing regimen and six were drug naive. Mutation K103N was observed in 56% (14/25) of the children while mutation T215Y was found in none. Two of the six drug naïve children also showed K103N mutation. Thus, Indian children drug naïve or treated with nevirapine containing regimens show a high rate of mutation conferring resistance to nevirapine which calls for a judicious use of nevirapine both in antenatal and postnatal setting.

Hydatid cyst of mediastinum

We report a case of hydatid cyst of the mediastinum in a 32-year-old female patient who was admitted with chest pain. CT scan reported posterior mediastinal mass towards the right side. Surgical exploration revealed a loculated cyst in posterior mediastinum on the right side, adherent to the overlying lung and underlying bone. Posterolateral thoracotomy was performed for cyst aspiration and excision. The patient was discharged on albendazole.

Evidence that differential packaging of the major platelet granule proteins von Willebrand factor and fibrinogen can support their differential release

BACKGROUND

von Willebrand factor (VWF) and fibrinogen are major storage proteins of platelet alpha-granules. VWF is synthesized by the megakaryocyte, the cell from which platelets bud, and fibrinogen is delivered to alpha-granules by endocytosis.

AIM

Considering biosynthetic origins, VWF and fibrinogen might be differentially packaged within platelets. We applied immunofluorescence microscopy to provide whole platelet, global information on the distributions of VWF and fibrinogen.

RESULTS

The distribution of VWF and fibrinogen were characterized in both the resting state and handling activated human platelets. Full cell volume image stacks were collected by spinning-disk confocal microscopy, corrected for a small pixel shift between green and red channels, deconvolved, and visualized in a three-dimensional space. In sum, we found that there was little overlap in the distribution of VWF and fibrinogen in resting state platelets. In an important control, the distributions of green and red secondary antibodies overlapped completely when different color secondary antibodies directed against the same first antibody were used. Moreover, the same result was observed using different first antibodies and switching second antibody color to switch the color of VWF and fibrinogen staining. No accumulation of fibrinogen in late endosomes or lysosomes was detected by co-staining with LAMP2, a late endosome/lysosome membrane protein. Significantly, we found that in handling activated platelets there was differential retention of fibrinogen-positive granules relative to VWF positive granules.

CONCLUSION

Our results indicate that VWF and fibrinogen are differentially packaged in human platelets. Moreover, the results suggest that differential packaging could support differential release of alpha-granule proteins.