An Investigation of High-Z Material for Bolus in Electron Beam Therapy

PURPOSE/OBJECTIVE(S)

Electron beams are frequently used for superficial tumors including: primary skin cancers, surgical scars, cutaneous lymphomas and benign conditions like keloids. However, due to electron beam characteristics the surface dose is 75-95% of the prescribed dose depending on beam energy thus requiring placement of bolus to augment surface dose. Various types of boluses; wet gauge/towel, superflab, superstuff, aquaplast, 3D printed plastics, customized dot-decimal bolus, thermoshield, brass and tantalum wire mesh are commonly used in clinics with variable difficulties that are not perfect. As majority of these devices do not snug to the skin contour and create air-gap that is known to produce significant dose perturbations creating hot and cold spot. The variable dosimetry has cosmetic implications and potentially increased risk of recurrence. A new cloth-like high-Z materials; Tungsten, (Z = 74) and Bismuth, (Z = 83) impregnated with silicone gel are now commercially available which is investigated in this study for bolus purpose.

MATERIALS/METHODS

Commercially available, super soft silicone-gel based submillimeter thin Tungsten and Bismuth sheets were investigated for bolus properties in electron beams in the range of 6-12 MeV using 10x10 cm2 applicator. These materials were tested on various body contour for perfect snug without any air traps. Using parallel plate ion chamber measurements were performed in a solid water phantom on a medical linear accelerator machine. Depth dose characteristics were measured to optimize the thickness for surface dose to be 100% for selected electron therapy.

RESULTS

Surface dose for a 10x10 cm2 cone for 6, 9, 12 MeV beams were measured to be 75.1%, 80.1% and 86.2%, respectively. Silicone-gel Tungsten and Bismuth sheets produce significant electrons thus increasing surface dose. Based on measured depth dose, our data showed that Tungsten sheets of 0.14 mm, 0.18 mm and 0.2 mm and Bismuth sheets of 0.42 mm, 0.18 mm and 0.2 mm provide 100% surface dose for 6, 9 and 12 MeV beams, respectively without any changes in depth dose except increasing surface dose.

CONCLUSION

The new Tungsten and Bismuth based silicone-gel clothlike sheets are extremely soft but high tensile metallic bolus materials that can fit flawlessly on any skin contour without any air trap or variable thickness or spillage of the water as in conventionally used wet gauge. Only 0.2 mm thick sheets are needed for 100% surface dose without degradation of the depth dose characteristics. These materials are reusable and ideal for bolus in electron beam treatment. This investigation opens a new frontier in designing new bolus materials optimum for patient treatment.

Treatment of Mantle and Inverted Y Fields in Modern Era: A VMAT Approach

PURPOSE/OBJECTIVE(S)

Hodgkin's lymphoma has been treated with combined modality therapy (chemotherapy and radiation) with a very high degree of success. Total Nodal Irradiation (TNI) performed with large AP/PA mantle fields for treatment of axillary, cervical, and mediastinal lymphatics, provide adequate coverage to the mediastinum and bilateral axillae and hila, while blocking lungs. The para-aortic and pelvic lymph nodes are treated with the so called inverted-Y AP/PA fields, which often includes the spleen in cases of TNI. Multileaf Collimators (MLC) have been tried, but due to the irregular shape of the fields and necessity of island blocking in 3D treatment, they have not been successful in full elimination of Cerrobend blocks. We hypothesize that using two or three matched Volumetric Modulated Arc Therapy (VMAT) fields will not only eliminate a need for Cerrobend blocks or island blocks, but will also provide better target coverage and better organs at risk (OAR) sparing.

MATERIALS/METHODS

Under IRB study, 10 patients were retrospectively planned using two or three matched VMAT technique for mantle and inverted-Y treatments of TNI that had been previously treated using MLC and Cerrobend block combination. Pinnacle treatment planning system version 16.2.1 was used to generate plans using mantle/inverted-Y technique and corresponding VMAT plans using 2-3 arcs per isocenter (2 isocenters per plan). Optimization was performed to cover targets with the prescribed dose of 1500 cGy in 10 fractions per institutional protocol. The VMAT plans were compared with traditional 3D plans.

RESULTS

VMAT consistently provided better or similar results to traditional field arrangements. Target coverage: V15Gy - 95.45% vs 77.99% (p = 0.00017), OAR coverage: total lung V5Gy 63.7% vs 68.8% (p = 0.016), bone marrow mean dose 539.1 cGy vs 727.8 cGy (p = 0.00047), Integral Dose 464.1 mJ vs 573.9 mJ (p = 0.0026). Low isodose lines- mean volume of 5 Gy isodose line was not significantly different - 24036 cc vs 25091 cc (p = 0.271). Cord maximum dose was 40% lower for VMAT plans (p = 0.00006). Mean bladder dose was similar in VMAT plans compared to 3D plan - 821.7 cGy vs 804.9 cGy (p = 0.454). One counter-intuitive result is that the mean integral dose for 10 patients was 24% lower for VMAT plans.

CONCLUSION

VMAT based mantle fields for TNI eliminates Cerrobend blocks and improve dosimetry significantly for target volumes and all OARs; including bone marrow, which plays important role in patient's recovery after chemotherapy, radiation and often stem cell transplantation in recurrent disease. Lower integral dose for VMAT plans is explained by the large irradiated in-fields and small out-of-field volumes. The VMAT process requires minimal effort for optimization and is economical compared to the traditional planning, while improving the target coverage and decreasing dose to OARs.

Stage IIIA Non-Small Cell Lung Cancer Treatment and Outcomes: A Single Institution Retrospective Analysis

PURPOSE/OBJECTIVE(S)

Treatment of locally advanced non-small cell lung cancer (NSCLC) remains challenging, with a multitude of treatment options available for Stage III patients. We hypothesized that Stage IIIA outcomes differ by treatment received.

MATERIALS/METHODS

We performed a retrospective review of NSCLC patients ≥18 years old with Stage IIIA disease treated 1/1/2010-03/01/2022. Demographics, treatment received, treatment outcomes, and failure patterns were collected. Progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier analysis. Kruskal-Wallis ANOVA was used to compare groups.

RESULTS

Of 352 patients identified, 160 had Stage IIIA NSCLC with a median follow-up of 29.1 months. Patients had a median age of 63 years, 79 (49.4%) were male, and 137 (85.6%) were current/former smokers (with 30 median pack-years). Patients were treated as follows: 17 (11%) surgery alone (S), 91 (57%) definitive radiation ± chemotherapy (CRT), 52 (33%) neoadjuvant therapy followed by surgery (Neo). 6 (12%) of the Neo group received chemoimmunotherapy, and 21 (51%) of the 41 CRT patients received adjuvant immunotherapy. Between the three groups, there were no significant differences in tumor size as measured by T-staging (p = 0.83) and baseline FEV1/FVC (p = 0.92). Median PFS was 33.5mo (95% CI 13.2-NA) for group S, 18.4mo (95% CI 12.7-42.2) for CRT, and 19.7mo (95% CI 13.9-NA) for Neo with no significant intergroup difference (p = 0.72). Median OS was 33.5mo (95% CI 13.2-NA) for S, 48.7mo (95% CI 36.0-88.9) for CRT, and 50.9mo (95% CI 41.9-NA) for Neo with no significant intergroup difference (p = 0.94). Among the 17 primary surgical patients, 11 (65%) experienced failure: 6 (35%) local, 5 (29%) regional, and 7 (41%) distant. Among the 91 CRT patients, 57 (63%) experienced failure: 40 (44%) local, 35 (38%) regional, and 28 (31%) distant. Among the 52 Neo patients, 26 (50%) experienced failure: 14 (27%) local, 15 (29%) regional, and 17 (33%) distant. There were no significant differences in rates of local failure (p = 0.26), regional failure (p = 0.59), distant failure (p = 0.79), or any failure (p = 0.41) among the three treatment groups. The most common locations for distant failure were pleural effusions (n = 15, 29%), CNS (n = 14, 27%), and bone (n = 11, 21%).

CONCLUSION

In this single institution retrospective study, we find no significant differences in PFS, OS, and failure patterns between patients with Stage IIIA NSCLC treated with definitive (chemo)radiation and neoadjuvant therapy. Numeric improvement in PFS in surgery-only patients is consistent with expected patient selection of this group. Further work in the immunotherapy era is needed.

Crowdsourcing Deep Learning Algorithms to Automatically Contour GI Luminal Organs on Serial MRIs

PURPOSE/OBJECTIVE(S)

A major barrier to a sustainable real-time adaptive MR-guided radiotherapy workflow is the time-consuming process of contouring the target and organs-at-risk (OARs) before the delivery of each fraction. While auto-contouring algorithms perform relatively well for many solid organs, the performance on luminal organs in the abdomen remain difficult due to the variability between patients and variability in daily shape and position. The purpose of this study is to evaluate the performance of crowdsourced deep learning algorithms to automatically contour GI luminal organs on serial MRIs.

MATERIALS/METHODS

The stomach, small intestines, and large intestines were manually contoured on MRIs from patients who had undergone radiotherapy on an MR-Linac by a team of radiation therapists and medical physicists and were verified by a board-certified radiation oncologist. The MRIs and the contours were de-identified and uploaded to Kaggle, an online machine learning competition platform with portion of the data open to the public as training data and the remaining data hidden as a test set. Prize money was offered to teams submitting the best auto-contouring algorithms based on the Dice coefficient and Hausdorff distance evaluation metrics. The average performance of the winning algorithm and of manual contours were compared using unpaired t-test.

RESULTS

Four hundred sixty-seven MRIs were collected from 107 patients who underwent 1-5 serial MRI sessions between 2015 and 2019. The most common anatomic site of treatment was the pancreas with 41 patients, followed by the liver with 38 patients. The manual contours of the stomach, small intestines, and large intestines on 4 representative MRIs had mean and standard deviation Dice coefficient of 0.90 +/- 0.02, 0.76 +/- 0.04, and 0.85 +/- 0.03 respectively and Hausdorff distance of 18.0 +/- 6.9, 35.5 +/- 12.6, and 32.3 +/- 12.3 mm respectively. The Kaggle competition was held from April to July 2022 and 1548 teams submitted algorithms for evaluation. The auto-contouring performance of the winning solution on the stomach, small intestines, and large intestines, when evaluated on a hold-out test set with 188 MRIs, had mean and standard deviation Dice coefficient of 0.92 +/- 0.04, 0.80 +/- 0.09, 0.85 +/- 0.08 respectively and Hausdorff distance of 15.2 +/- 11.2, 33.9 +/- 15.2, 34.8 +/- 20.3 mm respectively. Unpaired t-test was performed to compare the average performance across three organs of the human (N = 120) and of the algorithm (N = 564). The results suggest that average algorithm performance was statistically superior to manual contours for Dice (p = 0.01), yet not for Hausdorff (p = 0.64).

CONCLUSION

Crowdsourced deep learning algorithms to auto-contour GI luminal organs on serial MRIs perform superiorly compared to manual contours when using a Dice coefficient metric but not when using a Haudorff distance metric. These auto-contouring algorithms may be used to efficiently adapt radiotherapy plans according to the anatomy of the day for patients with abdominal tumors on MR-Linacs.

Effect of stabilizer on optical band gap of ZnO and their performance in dye-sensitized solar cells

ABSTRACT. In dye-sensitized solar cells, transparent metal oxide working electrodes play a vital role in defining the power conversion efficiency. It was found that the size of nanoparticles influences the electrical, optical properties of these electrodes. Herein, we describe the synthesis of ZnO with zinc acetate dihydrate and different stabilizers (diethylamine and triethylamine) by using a modified solvothermal process. The obtained materials were characterized by XRD, SEM, EDX, TEM, HRTEM, UV-visible, FTIR, and Raman methods. The crystallite sizes for ZnO-1 and ZnO-2 samples were indexed as 39.0 and 40.5 nm for the highest peak intensity with diethylamine and triethylamine stabilizer, respectively. We examine the effect of stabilizers on the morphology, optical band gap, and photovoltaic performance of the prepared ZnO. We found that ZnO prepared using diethylamine stabilizer exhibiting significant efficiency of 1.45%, open-circuit voltage 0.454 V, short-circuit current density 2.128 mA/cm2, and 0.66 fill factor were achieved under 44 mW/cm2 illumination powers with dye-3.                 KEY WORDS: Dye-sensitized solar cells, ZnO, Band gap, Photovoltaic performance   Bull. Chem. Soc. Ethiop. 2022, 36(1), 209-222.                                                        DOI: https://dx.doi.org/10.4314/bcse.v36i1.17                                                      

Expanding Opportunities in Treatment of Leukemia by Solid Lipid Nanoparticles

Background:

Leukemia is a severe type of blood cancer that involves an abnormal proliferation of blood-forming cells. Its conventional treatment faces many challenges, including resistance, lack of specificity and high unwanted toxicity of drugs. Nano drug delivery systems help in overcoming these challenges by delivering the drug to the target site actively or passively. Solid lipid nanoparticles are gaining popularity because they reduce unwanted toxicity, are biocompatible, increase bioavailability and are versatile in terms of incorporated agents (hydrophilic as well as lipophilic drugs, genes, enzymes, etc.).

Purpose:

The aim of this review is to discuss recent advancements in anti-leukemic therapy utilizing solid lipid nanoparticles (SLNs) as successful carriers in enhancing the efficiency of the treatment and bioavailability of the incorporated drug along with overcoming multidrug resistance.

Methods:

This review represents the existing literature on the applications of SLNs in anti-leukemic therapy. A qualitative literature review has been performed for this purpose. We performed keyword research in popular databases such as Google Scholar, Wiley, Elsevier, Scopus, Google patent and PubMed. Only articles published in English and from reputed journals from specific fields were considered. Benchmark studies having major importance from 2000 to 2020 were selected to follow the progress in the field across the globe.

Results:

This article improves the understanding of the role of SLNs in the treatment of leukemia. Traditional anti-leukemic therapy involves many challenges, including resistance, lack of specificity and high unwanted toxicity of drugs. SLNs are emerging as a better alternative to conventional delivery systems as they can reduce unwanted toxicity, are biocompatible, and can provide active as well as passive molecular targeting.

Conclusion:

SLNs provide several advantages in drug delivery for leukemia, including enhancement of efficiency and bioavailability and reduction of toxicity by virtue of their small size, lipid core, non-dependency on organic solvents and versatility in terms of incorporated drugs.

Does closed treatment of paediatric mandibular condyle fractures result in restitutional remodelling?

The treatment of paediatric mandibular condylar fracture (PMCF) is typically non-operative. The purpose of this study was to determine if non-operative management of PMCF results in a new condylar process of normal morphology to regenerate after closed treatment (restitutional remodelling). The specific aim of the study was to observe restitutional remodelling (RM) in PMCF and review the literature. The investigators designed and implemented a retrospective study on paediatric patients (age<12) with unilateral or bilateral condyle fractures treated with non-operative treatment between January 2005 and July 2015. Patients with complete records and at least 1-year follow-up were included in the study. Primary outcome variable was RM and secondary outcome variables were occlusion, maximal incisal opening (MIO), displacement, infection, facial asymmetry, and signs of temporomandibular joint ankylosis (TMJA). The study evaluated 41 patients {n=57 PMCF, (m:f-35:6)} of unilateral (n=25) and bilateral (n=16) PMCF. Fractured condyles remodelled to normal morphology in all the cases at follow-up. The Wilcoxon test revealed a statistically significant difference in MIO from the preoperative value to postoperative (p=0.001). Occlusion (except 1) was satisfactory in all cases, at follow-up with no gross facial asymmetry. There was no sign of infection at the surgical site (anterior mandible). None of the patients showed signs of TMJA at follow-up. The result of the present study demonstrates that RM of condylar fracture occurs with non-operative management. Non-operative management should be the point of care in PMCF, owing to the rapid RM, bone regeneration, and satisfactory outcome. Review of the literature also supports closed treatment.

Poultry-origin extraintestinal Escherichia coli strains carrying the traits associated with urinary tract infection, sepsis, meningitis and avian colibacillosis in India

AIM

In-depth 'One Health' risk assessment of extraintestinal pathogenic Escherichia coli (ExPEC) strains carrying the traits of urinary tract infection, sepsis, meningitis and avian colibacillosis in poultry of India.

METHODS AND RESULTS

A total of 230 E. coli isolates were recovered from chicken samples representing the different sources (faeces vs caeca), stages (poultry farms vs retails butcher shop) or environments (rural vs urban) of poultry in India. Among all poultry-origin E. coli isolates, 49 (21·1%) strains were identified as ExPEC possessing multiple virulence determinants regardless of their association with any specific phylogenetic lineages. Of particular, potentially virulent ExPEC pathotypes, that is, uropathogenic E.coli (UPEC, 20·4%), avian pathogenic E. coli (APEC, 34·6%), septicaemia-associated E. coli (SEPEC, 47·0%) and neonatal meningitis-causing E.39 coli (NMEC, 2·0%) were also detected among all ExPEC strains.

CONCLUSIONS

Our study is the first to assess ExPEC strains circulating in the different settings of poultry in India and significantly demonstrates their potential ability to cause multiple extraintestinal infections both in humans and animals.

SIGNIFICANCE AND IMPACT OF THE STUDY

The data of our study are in favour of the possibility that poultry-origin putative virulent ExPEC pathotypes consequently constitute a threat risk to 'One Health' or for food safety and a great concern for poultry production of India.

Etiology and characteristics of pediatric urethral strictures in a developing country in the 21st century

BACKGROUND

Urethral stricture disease in children is not uncommon as assumed; however, most of the information about the etiology, features, and natural history of pediatric strictures is extrapolations from adult series as the literature on this common entity is sparse, and most of the studies are small series.

OBJECTIVE

The current etiology and clinical features of urethral stricture disease in the pediatric population in the developing world were determined.

MATERIALS AND METHODS

The data of children with urethral stricture disease, who had undergone treatment in the tertiary center from 2001 to 2017, were retrospectively analyzed. After excluding girls, the database was analyzed for clinical presentation, possible causes of stricture, site and number of strictures, and length of stricture and for previous interventions. Subanalysis was performed for stricture etiology by patient age, stricture length, site, previous treatments, and presentation with paraurethral abscess.

RESULTS

A total of 195 boys with strictures were identified. The common causes of pediatric urethral stricture were traumatic (36.9%), iatrogenic (31.8%), and idiopathic (28.7%). The anterior urethra was the location of the stricture in 141 patients (72.3%). Iatrogenic causes (due to catheterization, hypospadias repair, and valve fulguration) accounted for the majority of anterior urethral strictures (61/141 or 43.2%). Younger children had a tendency to have an iatrogenic and idiopathic cause for strictures, whereas older children had a traumatic etiology; 18.6% of strictures in children younger than 10 years were secondary to trauma, whereas 44.9% of the strictures in patients older than 10 years were traumatic in origin. Trauma was the major cause of posterior urethral strictures (53/54 or 98.1%) and was always associated with pelvic fracture. Strictures due to lichen sclerosus or infectious cause were rare (5 patients or 2.6%). The length of strictures was longer in pan anterior urethral strictures (mean: 82.0 mm) than that of those due to lichen sclerosus (mean: 42.5 mm) and in patients who had undergone previous treatment (mean: 28.7 mm).

CONCLUSION

Iatrogenic causes such as catheterization and hypospadias repair account for the majority of anterior urethral stricture disease in the pediatric population, especially the younger age-group. However, as the child grows, there is a gradual preponderance of traumatic urethral strictures, including posterior urethral strictures.

Abstract P6-20-10: Role of GPR110 in breast cancer

Our long-term goal is to discover adhesion GPCR targets in breast cancer. Our previous studies have found GPR110 to be overexpressed in tumorigenic cell population as well as in anti-HER2 drug-resistant derivatives of HER2+ breast cancer cells. In subsequent studies, we found that GPR110 knockdown inhibited anchorage-independent cell growth, mammosphere formation, and invasion/migration of HER2+ breast cancer cells. Conversely, overexpression of GPR110 by lentiviral delivery of cDNA enhanced anchorage-independent cell growth, mammosphere formation, and invasion/migration in HER2+ breast cancer cells. In addition, GPR110 overexpression led to increase in the % of Aldefluor-positive tumorigenic cell population, further emphasizing the role of GPR110 as a mediator of tumorigenesis in addition to the metastatic processes in HER2+ breast cancer. Among various subtypes of breast cancer, GPR110 expression was higher in HER2+ and basal subtypes, most of which are triple-negative (negative for ER, PR, and HER2), compared to luminal A and B subtypes. GPR110 was either gene amplified or upregulated in 4% of all breast cancers based on the publicly available TCGA dataset. GPR110 overexpression predicted poorer recurrence-free survival in triple-negative breast cancer. Furthermore, GPR110 was overexpressed in brain metastatic lesions compared to mammary tumors in patient-derived xenograft models of triple-negative breast cancer (WHIM2 and WHIM30). Knocking down GPR110 reduced anchorage-dependent and -independent cell growth, mammosphere formation, and invasion/migration of triple-negative breast cancer cells. Overall, our results suggest that GPR110 may be a potential drug target in HER2+ and triple-negative breast cancer. Drug discovery efforts to identify GPR110 antagonists will provide useful pharmacological tools for validating GPR110 as a drug target in breast cancer. Since GPR110 is also overexpressed in various other types of cancer, understanding the mechanism of GPR110 upregulation and signaling in cancer is an important future direction.

This work was supported by the Department of Defense Grants W81XWH-14-1-0340 and W81XWH-14-1-0341 to Drs. Trivedi and Schiff, respectively.

Citation Format: Bhat R, Qin L, De Angelis C, Sahay D, Bhargava D, Creighton C, Yadav P, Yazdanfard S, Alrawi A, Yadav V, Vasaikar S, Nanda S, Sethunath V, Fu X, Zhang B, Narkar V, Schiff R, Trivedi M. Role of GPR110 in breast cancer [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 P6-20-10.

Eugenia jambolana extract reduces the systemic exposure of Sitagliptin and improves conditions associated with diabetes: A pharmacokinetic and a pharmacodynamic herb-drug interaction study

Eugenia jambolana (EJ) is an Indian traditional herb widely used for the treatment of diabetes mellitus. This herb is globally marketed as single or multi herb formulations. Many diabetes patients consume EJ extract oral hypoglycemic drugs together. This calls for a need to assess risks versus benefit of this co-administration.

In present investigation, pharmacodynamic and pharmacokinetic interactions of aqueous extract of EJ seeds at the dose of 400 mg/kg are studied with 10 mg/kg of oral hypoglycaemic drug sitagliptin (SITA) by co-administrating them for 28 days in streptozotocin (STZ) induced diabetic rats. The pharmacokinetic parameters of SITA were determined using HPLC-ESI-MS/MS and it was found that the combination treatment reduces the systemic exposure of SITA by showing 38.70% reduction in concentration maximum (Cmax) and 22.40% reduction in area under curve (AUC). Despite low levels of SITA, the combination demonstrated a significant reduction in blood glucose level when compared with individual drug and individual extract administered groups during pharmacodynamic study. In addition, the liver function, the kidney function and the lipid parameters were found to be significantly improved and beneficial effects were found with respect to food intake and water intake and urine output in case of combination treatment groups when compared with individual treatment groups. Histopathological examination of pancreatic tissue suggests its significant recovery of having normal acinus with better cell protection in combination treatment. In conclusion, the combination treatment demonstrated reduced systemic exposure of SITA without compromising on its antihyperglycemic activity and improvement in conditions associated with diabetes.

AA Homozygous Genotype of GSTP1 I105V Polymorphism in Oral Cancer: In Silico Screening, Molecular Dynamics Simulation and Activity Studies of Wild and Mutant GSTP1

Background: Highest incidence of oral squamous cell carcinoma (OSCC) has been reported in north-eastern India and causal association between cancer and raw areca-nut (RAN) consumption are well evident. Earlier studies revealed that monitoring the occurrence of precocious anaphase and expression of securin in blood lymphocytes can be a good biomarkers for cancer risk in RAN+lime chewers. Glutathione S-transferases (GSTs) are considered an important cellular detoxification system that provide protection against the effects of toxins and determine individual's cancer susceptibility. Aim: Although GST gene family has been extensively studied, its role as susceptibility factor in oral cancer risk in the RAN chewing population in Meghalaya state, India has not been explored. The association of polymorphisms in GSTP1 (Ile105Val) gene with OSCC risk in Meghalaya, India, was evaluated. Earlier both AA reference and the GG/AG mutant genotype of GSTP1 gene showed an association with different types of cancers. Methods: Genetic polymorphism was evaluated by genotyping 129 cases and 156 controls using PCR-RFLP method and validated by Sanger sequencing in a hospital-based case-control study. GSTP1's interaction status with c-Jun Kinase (JNK) was evaluated through protein-protein docking analysis and this was also validated experimentally by immunohistochemistry and qRT-PCR. Results: Individuals with AA allele of GSTP1 showed significant association with the risk of OSCC compared with individuals with AG/GG mutant genotypes in habit-matched “RAN-only” and “RAN+Tobacco” group. The binding geometry between JNK and GSTP1 was disrupted in mutant combinations. It was demonstrated that AA homozygous genotype of oral epithelial cells showed reduced c-Jun-phosphorylation and proapoptotic genes expression than AG/GG genotypes. In silico docking revealed that homodimeric GSTP1 with AA genotype showed weak catalytic activity in detoxification of RAN and tobacco toxins compared with the AG/GG mutant proteins. Interestingly, the quantitation of 8-Oxo-2´-deoxyguanosine in DNA digests by ELISA-kit showed no differences in these genotypes, however the frequency of sister-chromatid exchanges was significantly higher in individuals with GSTP1 AA genotype than GG genotype. Conclusion: Thus in this population, specific traditional habit along with GSTP1 AA genotype play a significant role in predisposition to oral cancer risk by showing higher DNA-lesions, might be caused by some specific RAN/tobacco metabolites, and lower c-Jun phosphorylation which may inhibit apoptosis.

Prevalence and spatial distribution of Ixodid tick populations in the forest fringes of Western Ghats reported with human cases of Kyasanur forest disease and monkey deaths in South India

Kyasanur forest disease (KFD) is a major tick-borne viral haemorrhagic fever caused by KFD virus (KFDV) (Flaviviridae). The disease was reported to be confined to five districts of Karnataka state India until 2011. During 2012-2016, emergence of KFD has been reported in newer areas of Karnataka and adjoining states. Therefore, survey of tick vectors was carried out in these new areas of Karnataka and adjoining states reported with monkey deaths and human cases of KFD. In all selected sites, ticks from the forest floor were collected by lint clothes using flagging method. Tick samples were tested for KFDV nucleic acid by real-time RT-PCR. A total of 4772 ticks, comprising eight species of genus Haemaphysalis and one species each of genus Amblyomma, Ixodes and Rhipicephalus was collected. Haemaphysalis spinigera, the principal vector of KFDV was the predominant tick species (59.5%) collected followed by H. turturis (8.6%). The abundance of H. spinigera ranged from 9.2 to 33.9 per man-hour in the six districts surveyed. Of 214 (4418 tick samples) pools screened by real-time RT-PCR, two pools of H. spinigera were positive for KFDV. High abundance of Haemaphysalis vectors in the six districts indicated that the districts are receptive for KFD outbreaks. KFDV was detected in the tick vectors in the new foci of the KFD. Data on tick distribution will be useful in creating KFD risk map for strengthening the ongoing preventive measures such as vaccination and supply of insect repellents to the high risk groups and intensive health education.

Late posttransplant lymphoproliferative disease: Report of a rare case and role of positron emission tomography-computed tomography

Posttransplant lymphoproliferative disease (PTLD) is an uncommon complication of immunosuppression after solid organ transplantation. Early PTLD (<1 year after transplantation) is frequently found around the allograft, whereas late PTLD (>1 year after transplantation) does not have such a preference. 18-Fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸FDG PET-CT) has clinical significance in the evaluation of PTLD. ¹⁸FDG PET-CT scan allows precise anatomic localization of FDG-avid lesions, hence helpful in staging of disease and evaluation of response to therapy. It can better characterize persistent lesions and differentiate residual tumor from fibrosis or necrosis. We present a rare case report of a perigraft PTLD developing 12 years after renal transplantation sparing the graft, in an Epstein–Barr virus-negative patient.