Determination of dose-response calibration curves for gamma radiation using gamma-H2AX immunofluorescence based biodosimetry.

Background: Gamma-H2AX immunofluorescence assay has gained popularity as a DNA double strand break marker. In this work, we have investigated the potential use of gamma H2AX immunofluorescence assay as a biological dosimeter for estimation of dose in our institution. Materials and methods: Seven healthy individuals were selected for the study and the blood samples collected from the first five individuals were irradiated to low doses (0-10 cGy) and high doses (50-500 cGy) in a telecobalt unit. All the samples were processed for gamma-H2AX immunofluorescence assay and the dose-response calibration curves for low and high doses were determined. In order to validate the determined dose-response calibration curves, the blood samples obtained from the sixth and seventh subjects were delivered a test dose of 7.5 cGy and 250 cGy. In addition, time and cost required to complete the assay were also reported. Results: The goodness of fit (R2) values was found to be 0.9829 and 0.9766 for low and high dose-response calibration curves. The time required to perform the gamma-H2AX immunofluorescence assay was found to be 7 hours and 30 minutes and the estimated cost per sample was 5000 rupees (~ 60 USD). Conclusion: Based on this study we conclude that the individual dose-response calibration curves determined with gamma-H2AX immunofluorescence assay for both low and high dose ranges of gamma radiation can be used for biological dosimetry. Further, the gamma-H2AX immunofluorescence assay can be used as a rapid cost-effective biodosimetric tool for institutions with an existing confocal microscope facility.

Evaluation of Deoxyribonucleic Acid Damage Using Neutral Comet Assay for High Radiation Doses: A Feasibility Study.

Purpose: This study aims to investigate the use of the neutral comet assay to assess deoxyribonucleic acid (DNA) damage in lymphocytes exposed to high doses of radiation. Materials and Methods: The research was conducted by obtaining informed consent, after which blood samples were taken from seven healthy individuals and this study was approved by the institutional ethics committee. At first, for the determination of dose-effect curves, samples obtained from the first five individuals were irradiated for doses ranging from 0 to 35 Gy after which they were processed under neutral comet assay. In order to verify the determined dose-effect curves, a test dose of 15 Gy was delivered to the samples obtained from the sixth and seventh individuals. The amount of DNA damage from the obtained comet assay images was analyzed using four comet assay parameters namely % tail DNA, tail length, tail moment (TM), and Olive TM (OTM). The most suitable comet assay parameter was evaluated based on the obtained dose-effect curves. Furthermore, the distribution of individual cells for each dose point was evaluated for all the four comet assay parameters to find the optimal parameter. Results: From our results, it was found that from 0 to 25 Gy all the four comet assay parameters fit well into a linear quadratic curve and above 25 Gy saturation was observed. Based on the individual cell distribution data, it was found that % tail DNA could be an optimal choice to evaluate DNA damage while using neutral comet assay for high-dose ionizing radiation. Conclusion: The neutral comet assay could be a potential tool to assess DNA damage from high doses of ionizing radiation greater than 5 Gy.

Deplastination: Preservation of Histological Structures and its Anticipated Role in the Field of Histopathology.

Deplastination is the process of reversing plastination such that a plastinated specimen can be reverted to its raw nature. This would enable its use in the field of histopathology. The present study aims to ascertain if deplastinates can be used for histopathological studies after a time period. Tissue samples were taken from patients undergoing maxillofacial surgeries for oral carcinomas after obtaining written informed consent. The 12 specimens obtained were divided into two groups. One set of tissues was processed for paraffin embedding after 10% formalin fixation. The other set was plastinated by S10 silicon plastination. After 3 months, the plastinates were deplastinated using sodium methoxide and processed for routine hematoxylin and eosin staining, similar to the formalin fixed specimens. The slides were quantitatively assessed on parameters like tissue architecture, staining property, and intracellular structure. In addition, the slides were qualitatively evaluated by a pathologist who was blinded to the mode of preservation to see if identification of pathological features was possible on a deplastinated slide. The formalin preserved specimens and deplastinated tissue slides compared closely in all three parameters tested with the need to identify the endpoint of deplastination. Qualitatively, deplastination did not hamper identification of tissue pathology. Deplastination increases the scope of a stored plastinate by allowing histological studies in the future without the need for any preservatives or special storage equipment. It preserves structure and maintains tissue pathology. An improved method of ensuring the endpoint of deplastination needs to be identified. Clin. Anat. 32:108-112, 2019. © 2019 Wiley Periodicals, Inc.

Contrast Enhanced Computed Tomographic Study on the Prevalence of Duodenal Diverticulum in Indian Population.

INTRODUCTION: Duodenal diverticulum (DD) is the second most common diverticulum, yet its incidence varies widely from 1-22% based on the mode of investigation. Computed Tomography (CT) of abdomen is the preferred modality to diagnose acute abdomen including those of complications of DD. Moreover, the prevalence of DD in Indian population is not yet been studied using CT. AIM: The current study aim to look for the prevalence of DD in Indian population using Contrast Enhanced Computed Tomography (CECT) abdomen. MATERIALS AND METHODS: A retrospective study was done to assess the presence of DD using the CECT abdomen of 565 patients. The number, size, location, wall thickness and the contents of the diverticulum were noted. The data obtained was analysed using SPSS version 17.0. The mean, percentage of frequency of each variable and the association of DD with pancreatitis, cholelithiasis and colonic diverticulum were also looked for. Frequencies and percentages were calculated for all categorical variables. Spearman's rho correlation was done for age, diameter and content of DD. RESULTS: The prevalence of DD in Indian population was 8.3% with the mean diameter of 17.13mm+7.26. The prevalence increased with age with no sex predilection. 89.3% were solitary and 10.64% were multiple. It was predominantly seen in the second part of duodenum (90.38%) and juxtapapillary type was the commonest. As the diameter of DD increased, fluid became its content. No significant association was observed between the presence of DD with pancreatitis, cholelithiasis or colonic diverticulum. A case of periampullary carcinoma arising from DD, a rare entity is being reported in this study. CONCLUSION: The prevalence of DD in Indian population is high compared to western population. DD has been attributed to the cases of acute abdomen and fluid alone as a content of DD with an incidence of 1.92% can be mistaken for a cystic neoplasm of pancreas. Rarely, a periampullary carcinoma can also arise from the wall of the pre-existing DD. This knowledge should be emphasised upon by the radiologist, surgeons and gastroenterologist who will be dealing with cases of acute abdomen and periampullary carcinoma.

Appropriate anthropometric indices to identify cardiometabolic risk in South Asians.

BACKGROUND: South Asians show an elevated cardiometabolic risk compared to Caucasians. They are clinically metabolically obese but are considered normal weight based on current international cut-off levels of several anthropometric indices. This study has two main objectives: (i) to predict the most sensitive anthropometric measures for commonly studied cardiometabolic risk factors, and (ii) to determine optimal cut-off levels of each of the anthropometric indices in relation to these cardiometabolic risk factors in South Asians. METHODS: The study was conducted on a random sample of 1178 adults of 20-80 years of age from an urban population of eastern India. Obesity, as evaluated by standard anthropometric indices of BMI (body mass index), WC (waist circumference), WHpR (waist-to-hip ratio) and WHtR (waist-to-height ratio), was individually correlated with cardiometabolic risk factors. Receiver operating characteristic (ROC) curve analyses were performed which includes: (i) the area under the receiver operating characteristic curve (AUROC) analysis to assess the predictive validity of each cardiometabolic risk factor; and (ii) Youden index to determine optimal cut-off levels of each of the anthropometric indices. RESULTS: Overall, AUROC values for WHtR were the highest, but showed variations within the sexes for each of the cardiometabolic risk factors studied. Further, WHpR cut-offs were higher for men (0.93-0.95) than women (0.85-0.88). WC cut-offs were 84.5-89.5 cm in men and 77.5-82.0 cm in women. For both sexes the optimal WHtR cut-off value was 0.51-0.55. The optimal BMI cut-offs were 23.4-24.2 kg/m2 in men and 23.6-25.3 kg/m2 in women. CONCLUSION: WHtR may be a better anthropometric marker of cardiometabolic risks in South Asian adults than BMI, WC or WHpR.

Bilateral tibial hemimelia I.

Congenital absence of tibia is a rare anomaly. We report a case of bilateral tibial hemimelia born to phenotypically normal parents. The two amputated legs with tibial dysplasia obtained from a 3-year-old boy were studied by radiography and anatomical dissection. The radiological evaluation revealed a normal hip joint. The lower end of femur was normal without any bifurcation, shortening or bowing. Fibula was present on both legs and there was no sign of bowing or doubling. Both right and left tibiae were absent. In addition, on the right side, five tarsal bones, two metatarsals and the corresponding digital rays were absent. On the left side, three tarsal bones were absent. Dissection of the amputated segments showed the presence of extensor digitorum longus, peroneus tertius, peroneus longus and brevis, gastrocnemius, and soleus. Following bilateral knee disarticulation the patient was fitted with prosthesis and is doing well.

Gender- and age-related differences in the morphology of the corpus callosum.

The size and shape of the adult corpus callosum may vary with gender and age. There is, however, little data on the morphology of the corpus callosum in the Indian population. The purpose of this study was to measure the size of the corpus callosum in normal adult Indian males and females, and to identify gender- and age-related differences. The size of the corpus callosum on midsagittal section was measured in 100 (50 males, 50 females) normal adult Indians using magnetic resonance imaging. The length of the corpus callosum, the width of the genu, trunk, and splenium, the area of the splenium, and the total area of the corpus callosum were measured. The length of the brain also was measured. Means were compared for significant difference by gender using the Student's unpaired t-test and by age using ANOVA followed by Duncan's multiple range test. Gender was estimated by discriminant function analysis and age was estimated by regression analysis from significant parameters. The corpus callosum was longer in males and the discriminant score to differentiate gender was determined with an accuracy of 66%. The length of the corpus callosum increased with age and regression equations for predicting age was derived from the length of the corpus callosum. The width of the trunk and genu decreased with age in males but not in females.