A dosimetric comparison of systemic peptide receptor radionuclide therapy and intra-arterial peptide receptor radionuclide therapy in patients with liver dominant gastroenteropancreatic neuroendocrine tumours.

OBJECTIVES: Intra-arterial radionuclide therapy (IART) treatment allows direct delivery of 177 Lu-DOTATATE to the overexpressed somatostatin-positive neuroendocrine liver metastases, which led to higher tumour concentration compared with systemic radionuclide therapy (SRT). The aim was to evaluate and compare the absorbed doses of both IART and SRT to organs and hepatic metastatic sites. METHODS: A total of 48 patients received SRT and IART. In SRT, activity was administered intravenously, whereas in IART, activity was administered directly into hepatic arteries. The sequential whole-body images were acquired at 2, 4, 24, 72 and 160 h. The reconstructed whole-body planar and single-photon emission computed tomography-computed tomography images were processed using the Dosimetry Toolkit for the estimation of normalized cumulated activity in the organs and tumour lesions. The absorbed dose was computed using OLINDA EXM 2.0 software. RESULTS: The median absorbed dose (mGy/MBq) of kidneys and spleen in IART was compared with SRT and found to be decreased by 30.7% ( P  = 0.03) and 37.5% ( P  = 0.08), whereas it was found to be increased by 40% ( P  = 0.26) and 8.1% ( P  = 0.28) in the liver and lungs. The median dose (mGy/MBq) of tumours determined in IART was found to be increased by 62.2% ( P  = 0.04). CONCLUSION: IART with 177 Lu-DOTATATE significantly increases tumour dose while reducing overall systemic toxicity in comparison to SRT treatment. After considering the maximum tolerance limit of kidneys in peptide receptor radionuclide therapy, the number of treatment cycles and injected activity can be optimized further with IART for better response and survival.

Radiological and Morphometric Study of the Emissary Foramens and Canal in the Posterior Cranial Fossa of the Human Skull with Its Neurosurgical Significance.

Objective The posterior condylar canals (PCCs), posterior condylar veins (PCVs), occipital foramen (OF), and occipital emissary vein (OEV) are potential anatomical landmarks for surgical approaches through the lateral foramen magnum. We performed the study to make morphometric and radiological analyses of the various emissary foramens and vein in the posterior cranial fossa. Methods Morphometric study were performed on 95 dry occipital bones and radiological analyses on computed tomography (CT) angiography images of 150 patients. The number of OFs on both sides was recorded and PCC length and mean diameters of the internal and external orifices of PCC were measured for bony specimens. Prevalence of PCV and PCV size was investigated using CT angiography. Results Mean PCC length was higher in the left side (9.85 ± 2.5). Mean diameter of the internal orifice and the external orifice diameter were almost the same. The majority of PCCs (75-79.33%) had 2 to 5 mm diameter; only 4 to 9.2% were small in size (< 2 mm). In CT angiography, PCV was not identified in 23 (15.33%) patients. PCVs were located bilaterally in 105 (70%) and unilaterally in 22 (20.5%) patients. Only 11.3% of PCVs were large in size (> 5 mm), 80% of PCVs were medium sized (2-5 mm), and 8.6% were small sized (< 2 mm). Conclusion Normal values of OF, PCC, PCV, and OEV could serve as a future reference for the understanding of the physiology of craniocervical venous drainage, which is necessary to avoid surgical complications and can also serve as a guide to surgical interventions for pathologies of the posterior cranial fossa, such as tumors and injuries.

Fentanyl Assay Derived from Intermolecular Interaction-Enabled Small Molecule Recognition (iMSR) with Differential Impedance Analysis for Point-of-Care Testing.

Rapid and effective differentiation and quantification of a small molecule drug, such as fentanyl, in bodily fluids are major challenges for diagnosis and personal medication. However, the current toxicology methods used to measure drug concentration and metabolites require laboratory-based testing, which is not an efficient or cost-effective way to treat patients in a timely manner. Here, we show an assay for monitoring fentanyl levels by combining the intermolecular interaction-enabled small molecule recognition (iMSR) with differential impedance analysis of conjugated polymers. The differential interactions with the designed anchor interface were transduced through the perturbance of the electric status of the flexible conducting polymer. This assay showed excellent fentanyl selectivity against common interferences, as well as in variable body fluids through either testing strips or skin patches. Directly using the patient blood, the sensor provided 1%-5% of the average deviation compared to the "gold" standard method LC-MS results in the medically relevant fentanyl range of 20-90 nM. The superior sensing properties, in conjunction with mechanical flexibility and compatibility, enabled point-of-care detection and provided a promising avenue for applications beyond the scope of biomarker detection.

Dosimetry in Lu-177-PSMA-617 prostate-specific membrane antigen targeted radioligand therapy: a systematic review.

BACKGROUND: 177Lu-prostate-specific membrane antigen (PSMA) gained popularity as a choice of agent in the treatment of patients with advanced prostate cancer or metastatic castration-resistant stage of prostate carcinoma (mCRPC) diseases. However, this treatment may cause fatal effects, probably due to unintended irradiation of normal organs. We performed an extensive systematic review to assess the organs at risk and the absorbed dose received by tumor lesions in 177Lu-PSMA therapy. DESIGN: In this review, published peer-reviewed articles that cover clinical dosimetry in patients following peptide radionuclide ligand therapy using 177Lu-PSMA have been included. Two senior researchers independently checked the articles for inclusion. A systematic search in the database was made using PubMed, Publons and DOAJ. All selected articles were categorized into three groups: (1) clinical studies with the technical description of dosimetry in 177Lu-PSMA therapy (2) organ dosimetry in 177Lu-PSMA therapy or (3) tumor dosimetry in 177Lu-PSMA therapy. RESULT: In total, 182 citations were identified on PSMA therapy and 17 original articles on 177Lu-PSMA dosimetry were recognized as eligible for review. The median absorbed dose per unit of administered activity for kidneys, salivary, liver, spleen, lacrimal and bone marrow was 0.55, 0.81, 0.1, 0.1, 2.26 and 0.03 Gy/GBq, respectively. The median absorbed dose per unit of activity for tumor lesions was found in a range of 2.71-10.94 Gy/GBq. CONCLUSION: 177Lu-PSMA systemic radiation therapy (SRT) is a well-tolerated and reliable treatment option against the management of the mCRPC stage of prostate carcinoma. Lacrimal glands and salivary glands are the major critical organs in 177Lu-PSMA SRT. Besides, tumors receive 3-6 times higher absorbed doses compared to organs at risk.

Biological Effects Associated with Internal and External Contamination of Diagnostic Nuclear Medicine Sources: An In vitro Study.

AIM: In a Nuclear Medicine department, the risk of external and internal contamination in radiation workers is much higher than in other medical radiation facilities. The risk associated with both types of contaminations should be quantified to estimate the radiation dose received by the personal. Here, we designed an in vitro model to see the impact of internal and external contamination of F-18 and Technetium-99 m (Tc-99 m) on DNA damages. METHODOLOGY: Chinese hamster lung fibroblast V79 was used for all of the experiments. Irradiation was performed internally and externally (scenarios activity is mixed with the cell line [Internal] and activity kept at 1 cm distance from cell line [external]) using two different diagnostic radioactive sources (Tc-99 m and F-18) of known quantity 37 MBq. Total cumulated activity (MBq-min) was calculated up to one half-life of sources for both internal and external setups. An alkaline single gel electrophoresis technique (comet assay) was used for DNA damage analysis. Olive tail moment (OTM) was used to characterize DNA damage. RESULTS: We have not observed any significant difference (P > 0.05) in OTM between internal and external irradiation for cumulated activity presented before one half-life of both diagnostic isotopes. However, a significant difference in OTM was noted between internal and external irradiation for cumulated activity presented at one half-life of radioactive sources (P < 0.05). DNA damage with internal exposure was found to be 17.28% higher for F-18 and 23% higher for Tc-99 m than external exposure at one half-life of radioactive sources. Overall, we noted greater DNA damage in F-18 as compared to Tc-99 m. CONCLUSIONS: Our in vitro study practically demonstrated that internal contamination is more hazardous than external exposure.

A SIMPLE AND NOVEL APPROACH TO STUDY KINETICS AND ESTIMATE RADIATION DOSES FROM INTERNALLY ADMINISTERED RADIOPHARMACEUTICALS USING AN EXTERNAL DOSE MEASUREMENT SYSTEM.

Various methods have been reported to study radiotracer kinetics and make internal dosimetry feasible in the routine clinical nuclear medicine practice. The aim of the present study was to quantify cumulative activity and organ doses using an indigenously designed and fabricated external dose measurement system. The measurement was demonstrated on patients undergoing whole-body (WB) 18F-FDG (Fluorine-18-fluorodeoxyglucose) direct positron emission tomography/computed tomography investigations. An external dose measurement system comprising of an ionisation chamber-survey meter and the movable focussing collimator was used to quantify the uptake of 18F-FDG in liver and brain. Cumulative activity and normalised cumulative activity in these organs were calculated. The results were validated by performing measurements on a phantom uniformly filled with known activity of 18F-FDG.The difference in the absorbed dose estimated with and without collimator was statistically significant (p < 0.05). The external dose measurement technique is relatively novel, convenient and reliable for the assessment of internal absorbed dose of organs.

Analysis of absorbed dose in radioimmunotherapy with 177Lu-trastuzumab using two different imaging scenarios: a pilot study.

OBJECTIVES: Internal organ dosimetry is an important procedure to demonstrate the reliable application of 177Lu-trastuzumab radioimmunotherapy for human epidermal growth factor receptor-positive metastatic breast cancers. We are reporting the first human dosimetry study for 177Lu-trastuzumab. Another objective of our study was to calculate and compare the absorbed doses for normal organs and tumor lesions in patients before radioimmunotherapy with 177Lu-trastuzumab using two different imaging scenarios. METHODS: Eleven patients (48.27 ± 8.95 years) with a history of metastatic breast cancer were included in the study. Postadministration of 177Lu-trastuzumab (351.09 ± 23.89 MBq/2 mg), acquisition was performed using planar and hybrid imaging scenarios at 4, 24, 72 and 168 h. Single-photon emission computed tomography/computed tomography imaging was performed at 72 h postinjection. Acquired images were processed using Dosimetry Toolkit software for the estimation of normalized cumulated activity in organs and tumor lesions. OLINDA/EXM 2.0 software was used for absorbed dose calculation in both scenarios. RESULTS: Significant difference in normalized cumulated activity and the absorbed dose is noted between two imaging scenarios for the organs and tumor lesions (P < 0.05). Mean absorbed dose (mGy/MBq) estimated from heart, lungs, liver, spleen, kidney, adrenal, pancreas and colon using planar and hybrid scenarios were 0.81 ± 0.19 and 0.63 ± 0.17; 0.75 ± 0.13 and 0.32 ± 0.06; 1.26 ± 0.25 and 1.01 ± 0.17; 0.68 ± 0.22 and 0.53 ± 0.16; 0.91 ± 0.3 and 0.69 ± 0.24; 0.18 ± 0.04 and 0.11 ± 0.02; 0.25 ± 0.22 and 0.09 ± 0.02 and 0.75 ± 0.61 and 0.44 ± 0.28, respectively. CONCLUSIONS: On the basis of our dosimetric evaluation, we concluded that radioimmunotherapy with 177Lu-trastuzumab is well tolerated to be implemented in routine clinical practice against HER2 positive metastatic breast cancer. Liver is the main critical organ at risk. Hybrid scenario demonstrated significantly lower absorbed doses in organs and tumors compared to the multiplanar method.

Ferrimicrobium acidiphilum Exchanges Electrons With a Platinum Electrode via a Cytochrome With Reduced Absorbance Maxima at 448 and 605 nm.

Ferrimicrobium acidiphilum is a Gram-positive member of the Actinobacteria phylum that can respire aerobically or anaerobically with soluble Fe(II) or Fe(III), respectively, in sulfuric acid at pH 1.5. Cyclic voltammetry measurements using intact F. acidiphilum at pH 1.5 produced fully reversible voltammograms that were highly reproducible. The maximum current observed with the anodic peak was considerably less than was the maximum current observed with the cathodic peak. This difference was attributed to the competition between the platinum electrode and the soluble oxygen for the available electrons that were introduced by the cathodic wave into this facultative aerobic organism. The standard reduction potential of the intact organism was determined to be 786 mV vs. the standard hydrogen electrode, slightly more positive than that of 735 mV that was determined for soluble iron at pH 1.5 using the same apparatus. Chronocoulometry measurements conducted at different cell densities revealed that the intact organism remained in close proximity to the working electrode during the measurement, whereas soluble ionic iron did not. When the cyclic voltammetry of intact F. acidiphilum was monitored using an integrating cavity absorption meter, the only small changes in absorbance that were detected were consistent with the participation of a cellular cytochrome with reduced absorbance peaks at 448 and 605 nm. The cytochrome that participated in the exchange of electrons between the intact organism and extracellular solid electrodes like platinum was the same cytochrome whose oxidation was previously shown to be rate-limiting when the organism respired aerobically on extracellular soluble iron.

An evaluation of DNA double strand break formation and excreted guanine species post whole body PET/CT procedure.

Ionizing radiation-induced oxidation and formation of deoxyribonucleic acid (DNA) double strand breaks (DSBs) are considered the exemplar of genetic lesions. Guanine bases are most prone to be oxidized when DNA and Ribonucleic acid (RNA) are damaged. The repair processes that are initiated to correct this damage release multiple oxidized guanine species into the urine. Hence, the excretion of guanine species can be related with the total repair process. Our study quantified the total DSBs formation and the amount of guanine species in urine to understand the DNA break and repair process after whole body (WB) exposure to 18F-FDG positron emission tomography/computed tomography (PET/CT). A total of 37 human participants were included with control and test groups and the average radiation dose was 27.50 ± 2.91 mSv. γ-H2AX foci assay in the collected blood samples was performed to assess the DSBs, and excreted guanine species in urine were analyzed by a competitive ELISA method. We observed a significant increase of DNA damage that correlated well with the increasing dose (p-value 0.009) and body weight (p-value 0.05). In the test group, excreted guanine species in urine sample significantly increased (from 24.29 ± 5.82 to 33.66 ± 7.20 mg/mmol creatinine). A minimum (r2 = 0.0488) correlation was observed between DSBs formation and excreted guanine species. A significant difference of DNA damage and 8-OHdG formation was seen in the test group compared to controls. Larger population studies are needed to confirm these observations, describe the fine-scale timing of changes in the biomarker levels after exposure, and further clarify any potential risks to patients from PET/CT procedures.

Normal Skeletal Standardized Uptake Values Obtained from Quantitative Single-Photon Emission Computed Tomography/Computed Tomography: Time-Dependent Study on Breast Cancer Patients.

AIM: To estimate the standard uptake values (SUVs) of Tc-99m methylene-diphosphonate (Tc-99m MDP) from normal skeletal sites in breast cancer patients using quantitative single-photon emission computed tomography (SPECT). MATERIALS AND METHODS: A total of 60 breast cancer patients who underwent Tc-99m MDP SPECT/CT study at different postinjection acquisition times were included in this study. Based on postinjection acquisition time, patients were divided into four study groups (n_15 each), i.e. Ist (2 h), IInd (3 h), IIIrd (4 h), and IVth (5 h). Image quantification (SUVmax and SUVmean) was performed using Q.Metrix software. Delineation of volume of interest was shaped around different bones of the skeletal system. RESULTS: The highest normal SUVmax and SUVmean values were observed in lumber and thoracic vertebra (8.89 ± 2.26 and 2.89 ± 0.58) for Group I and in pelvis and thoracic (9.6 ± 1.32 and 3.04 ± 0.64), (10.93 ± 3.91 and 3.65 ± 0.97), (11.33 ± 2.67 and 3.65 ± 0.22) for Group II, III and IV, respectively. Lowest normal SUVmax and SUVmean values were observed in humerus and ribs (3.22 ± 0.67 and 0.97 ± 0.18), (5.16 ± 1.82 and 1.18 ± 0.16) for Group I, IV, and in humerus (3.17 ± 0.58 and 0.85 ± 0.26), (3.98 ± 1.12 and 1.04 ± 0.28) for Group II and III, respectively. Significant difference (P < 0.05) noted in SUVmax for sternum, cervical, humerus, ribs, and pelvis with respect to time. However, significant difference (P < 0.05) noted in SUVmean for all skeletal sites with respect to time. CONCLUSIONS: Our study shows variability in normal SUV values for different skeletal sites in breast cancer patients. Vertebral bodies and pelvis contribute highest SUV values. Time dependency of SUVs emphasizes the usefulness of routinely acquired images at the same time after Tc-99m MDP injection, especially in follow-up studies.

Corticosteroid Administration Is Associated With Improved Outcome in Patients With Severe Acute Respiratory Syndrome Coronavirus 2-Related Acute Respiratory Distress Syndrome.

OBJECTIVES: To compare the clinical outcome of mechanically ventilated patients with severe acute respiratory syndrome coronavirus 2-related acute respiratory distress syndrome, who received corticosteroid with those who did not. DESIGN: Retrospective analysis. SETTING: Intensive care setting. PATIENTS: All adult mechanically ventilated patients, who were admitted to the ICU between March 20, 2020, and May 10, 2020, for severe acute respiratory syndrome coronavirus 2-related acute respiratory distress syndrome. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Cohort was divided into two groups based on corticosteroid administration. The primary outcome variable was ventilator-free days at day 28. Secondary outcome variable was ICU-free days at day 30, and hospital-free days at day 30. Consecutive 61 mechanically ventilated patients with severe acute respiratory syndrome coronavirus 2-related acute respiratory distress syndrome were analyzed. Patient in corticosteroid group as compared with noncorticosteroid group have higher 28-day ventilator-free days (mean, 10.2; median, 7 [interquartile range, 0-22.3] vs mean, 4.7; median, 0 [interquartile range, 0-11]; p = 0.01).There was no significant difference noted in secondary outcomes (ICU-free days at day 30 and hospital-free days at day 30). CONCLUSIONS: Among mechanically ventilated severe acute respiratory syndrome coronavirus 2-related acute respiratory distress syndrome patients, corticosteroids use was associated with significant improvement in 28-day ventilator-free days at day 28, but no significant improvement in ICU-free days at day 30, and hospital-free days at day 30.

Computed Tomographic Study of Remarkable Anatomic Variations in Paranasal Sinus Region and their Clinical Importance - A Retrospective Study.

INTRODUCTION: With the advent of functional endoscopic sinus surgery and coronal computed tomography (CT) imaging, more attention has been paid toward paranasal region anatomy. Detailed knowledge of anatomic variations in paranasal sinus region is critical for surgeons performing endoscopic sinus surgery as well as for the radiologist involved in the pre- and post-operative assessment. The anatomical variants with some accompanying pathologies would directly influence the success of diagnostic and therapeutic management of paranasal sinus diseases. Our study intends to explore the anatomy of paranasal air sinus through CT and to describe its variants, which may predispose to chronic sinusitis and complications in endoscopic sinonasal surgery. MATERIALS AND METHODS: This was a retrospective study carried out in a tertiary institution. Two hundred and fifty patients without paranasal sinus symptoms who presented for head CT studies and gave consent for a coronal section scan of the paranasal sinuses to be taken in addition to the axial section of the head were included in the study. The CT examination was performed with GE Hispeed-NX/I Base-2002 Dual Slice Helical CT machine. RESULTS: Among 250 study population, 100 were females and 150 males. Among these 423 cases of anatomical variants were observed. The most common anatomical variants were pneumatization of the middle nasal turbinates 30.73%. This is followed by agger nasi cells 21.64%, Haller's cells 22.91%, septal deviation 21.91%, and sphenoid sinus septation (20.18%). DISCUSSION: CT is the gold standard in the radiologic investigation of the paranasal sinuses, sinonasal lesions, and inflammatory disease or pre- and post-surgical assessment. It has the capability of disclosing in greatest detail any anatomical variations, which could be causing or precipitating the sinusitis.

Real World Outcomes Associated with Idarucizumab: Population-Based Retrospective Cohort Study.

BACKGROUND: Idarucizumab reverses the anticoagulant effect of dabigatran, but few comparative studies have reported on clinical outcomes with idarucizumab. OBJECTIVE: Our objective was to determine the effect of idarucizumab on clinical outcomes. METHODS: We conducted a retrospective cohort study in a nationally representative sample of hospitals in the United States. The study population included adults ≥ 18 years who were hospitalized for dabigatran-associated major bleeding between January 1, 2015 and December 31, 2017. We compared idarucizumab-exposed patients to the unexposed group. Our primary outcome of interest was in-hospital mortality. RESULTS: We included 266 exposed and 1345 non-exposed participants across 271 hospitals. Among participants with gastrointestinal bleeding, there was no statistically significant difference in the odds of in-hospital mortality [9/153 (5.9%) vs 37/1124 (3.3%); adjusted odds ratio = 1.39, 95% confidence interval 0.51-3.45] between the idarucizumab-exposed and non-exposed groups. Among participants with intracranial bleeding, there was an excess of in-hospital mortality [13/112 (11.6%) vs 6/217 (2.8%)] associated with idarucizumab exposure, but limitations include sparse data and the inability to rule out residual confounding or confounding by disease severity. CONCLUSIONS: Among a large nationally representative sample of adult patients with dabigatran-associated major bleeding in the United States, we found no difference in in-hospital mortality among patients with gastrointestinal bleeding associated with idarucizumab exposure. An excess risk of in-hospital mortality associated with idarucizumab exposure among participants with intracranial bleeding deserves further exploration.

18F-FDG-induced DNA damage, chromosomal aberrations, and toxicity in V79 lung fibroblast cells.

18F-FDG PET/CT imaging is used in the diagnosis of diseases, including cancers. The principal photons used for imaging are 511 ke V gamma photons resulting from positron annihilation. The absorbed dose varies among body organs, depending on administered radioactivity and biological clearance. We have attempted to evaluate DNA double-strand breaks (DSB) and toxicity induced in V79 lung fibroblast cells in vitro by 18F-FDG, at doses which might result from PET procedures. Cells were irradiated by 18F-FDG at doses (14.51 and 26.86 mGy), comparable to absorbed doses received by critical organs during PET procedures. The biological endpoints measured were formation of γ-H2AX foci, mitochondrial stress, chromosomal aberrations, and cell cycle perturbation. Irradiation induced DSB (γH2AX assay), mitochondrial depolarization, and both chromosome and chromatid types of aberrations. At higher radiation doses, increased aneuploidy and reduced mitotic activity were also seen. Thus, significant biological effects were observed at the doses delivered by the 18F-FDG exposure and the effects increased with dose.

Diagnosis of immune checkpoint inhibitor-associated myocarditis: A systematic review.

BACKGROUND: Myocarditis is a rare but severe adverse event associated with immune checkpoint inhibitors, its diagnosis depending on a high index of suspicion and appropriate investigations. Our objective was to systematically review the diagnostic approaches to myocarditis associated with immune checkpoint inhibitors. METHODS: The systematic review was conducted according to the PRISMA guidelines (PROSPERO Registration: CRD42018097247). We searched Medline and Embase for case reports, case series, and observational studies published in journal articles or presented as conference abstracts that describe patients who developed myocarditis after immune checkpoint inhibitor therapy. RESULTS: After a review of 2326 citations, we included 88 cases (53 case reports/series published in journal articles and 35 cases in the observational study). Serum troponin was elevated in 98% of the case reports and 94% of participants in the observational study. ST changes including ST elevation were present in almost a third of case reports. Echocardiography revealed preserved left ventricular ejection fraction in 32% of case reports and 51% of cases in the observational study; however, preserved systolic function did not predict greater survival. Patients who suffered poorer prognosis tended to have major conduction defects or ventricular arrhythmias more frequently than patients who did not. Acute myocardial ischemia was ruled out in all cases (n = 31) when the diagnostic workup included coronary angiography. CONCLUSIONS: Immune checkpoint inhibitor-associated myocarditis is characterized by elevation of cardiac troponin levels and non-specific electrocardiographic changes. Early coronary angiography may distinguish it from myocardial ischemia or myocardial infarction.

Edge Packing Artifact Mimicking Lytic-Sclerotic Lesion in Bone Scan Due to Spontaneous Malfunction of Photomultiplier Tubes in the Gamma Camera.

Edge packing is a kind of nonuniformity artifact, which usually appears as an accumulation of counts at the edge of the field of view compared to the central region. The common causes of edge packing artifact in the image are defective collimator, noncalibrated photomultiplier tube (PMT), and improper adjustment of deflector plates of CRT. We hereby discuss the occurrence of edge packing artifact due to a problem with the PMTs in the anterior head of gamma camera system during acquisition of bone scintigraphy which mimics as pathological lytic-sclerotic lesion during whole-body image at anterior acquisition. The artifact was successfully removed after the replacement of malfunctioning PMTs.

Impact of Body Mass Index on Gates Method of Glomerular Filtration Rate Estimation: A Comparative Study with Single Plasma Sample Method.

PURPOSE OF THE STUDY: This study aims to compare glomerular filtration rate (GFR) estimated by Gates method using gamma camera (GC) with single plasma sample method (SPSM) in people with normal and abnormal body mass index (BMI) using SPSM as gold standard. MATERIALS AND METHODS: It was single-center prospective study including 60 voluntary kidney donors. Technetium-99m labeled Diethylene Triamine Pentaacetic Acid (99mTc-DTPA) was administered intravenous under GC. GFR was calculated using Gates Method. After the scan, the subjects were called again after 180 min of injection of 99mTc-DTPA. Then, a 3 ml venous blood sample was obtained from the contralateral arm. Russell's formula was used to determine the GFR by SPSM. RESULTS: Mean GFR calculated by SPSM and Gates' method, was 94.0 ± 15.2 ml/min/1.73 m2 and 87.3 ± 16 ml/min/1.73 m2 respectively. Moderate correlation noted between two methods (r = 0.71, P < 0.0001). Significant correlation noted between GFR calculated by SPSM and Gates method in people with normal BMI (r = 0.92) with no significant statistical difference (P = 0.8). However, only moderate correlation noted between GFR calculated by SPSM and Gates method in people with BMI outside normal range (r = 0.71) with a significant statistical difference (P = 0.0002). CONCLUSION: Gates method of GFR estimation using GC shows significant correlation with plasma sample technique in people with normal BMI. In people with BMI outside normal range, it significantly underestimates GFR.

Quantification of DNA damage in patients undergoing non-contrast and contrast enhanced whole body PET/CT investigations using comet assay and micronucleus assay.

Objective: To quantify DNA damage in patients undergoing non-contrast and contrast-enhanced 18F-FDG PET/CT whole body positron emission tomography/computed tomography (WB PET/CT) investigations using comet assay technique and micronucleus assay, and to study the effect of other baseline parameters of patients on DNA damage. Methodology: Eighty-four patients referred for 18F-FDG PET/CT investigation were included in the study of which 44 patients underwent contrast-enhanced WB PET/CT and 40 patients underwent non-contrast WB PET/CT investigations. The investigations were performed on Discovery 690 PET/CT. For contrast-enhanced investigation, Omnipaque300 was injected intravenously based on the patient body weight. Absorbed dose resulting from the intravenous administration of 18F-FDG was estimated using the ICRP 106 dose coefficients. Radiation dose from the acquisition of CT scans was estimated using CT dose index and dose-length product. Blood samples were collected from the patients for DNA damage analysis. Comet assay and MN assay was used to assess the DNA damage. The Differences in the comet TM (Tail Moment) and MNBC % in both groups were calculated. Result: The radiation dose received by the study population during 18F-FDG WB PET/CT examination was 27.03 ± 2.33 mSv. Comet TM and percentage frequency of MNBC % was 65.22 ± 35.42 and 18.55 ± 10.14, respectively in the patients injected with contrast and 42.49 ± 28.52 and 13.76 ± 7.52 for non-contrast group. Significant increase in DNA damage was observed in the contrast group as compared to non-contrast group. Significant association was observed between patient weight, contrast volume and TM and MNBC%. Baseline parameters of the patients did not show significant correlation with TM and MNBC%. Conclusion: The patients undergoing contrast-enhanced WB PET/CT investigations have demonstrated higher DNA damage. The DNA damage was also observed to be more in heavier patients. The other baseline parameters of patients like age, sex, CBG, serum creatinine did not show any correlation with DNA damage.

Tunable Three-Dimensional Nanostructured Conductive Polymer Hydrogels for Energy-Storage Applications.

Three-dimensional (3D) nanostructured conducting polymer hydrogels represent a group of high-performance electrochemical energy-storage materials. Here, we demonstrate a molecular self-assembly approach toward controlled synthesis of nanostructured polypyrrole (PPy) conducting hydrogels, which was "cross-linked" by a conjugated dopant molecule trypan blue (TB) to form a 3D network with controlled morphology. The protonated TB by ion bonding aligns the free sulfonic acid groups into a certain spatial structure. The sulfonic acid group and the PPy chain are arranged by a self-sorting mechanism to form a PPy nanofiber structure by electrostatic interaction and hydrogen bonding. It is found that PPy hydrogels doped with varying dopant concentrations and changing dopant molecules exhibited controllable morphology and tunable electrochemical properties. In addition, the conjugated TB dopants promoted interchain charge transport, resulting in higher electrical conductivity (3.3 S/cm) and pseudocapacitance for the TB-doped PPy, compared with PPy synthesized without TB. When used as supercapacitor electrodes, the TB-doped PPy hydrogel reaches maximal specific capacitance of 649 F/g at the current density 1 A/g. The result shows that PPy nanostructured hydrogels can be tuned for potential applications in next-generation energy-storage materials.

Morphometric and Anatomic Variations of Foramen Ovale in Human Skull and Its Clinical Importance.

OBJECTIVE: There is a paucity of information regarding the specific anatomy and clinical significance of variations of foramen ovale (FO). The present study was undertaken to define this anatomy in more detail and to review the literature regarding these anatomic variations. MATERIALS AND METHODS: A total of 124 adult human dry skulls were analyzed for the variations in appearance and number of FO being noted. The length and width of the FO of both sides were determined using digital vernier calipers and area (A) was also calculated and analyzed. RESULTS: Of 82 adult skulls, the values for the right side was 7.64 ± 1.194 mm, 5.128 ± 0.827 mm, and 30.808 ± 7.545 mm2 and for the left side the values was 7.561 ± 1.123 mm, 5.244 ± 0.950 mm, and 31.310 ± 8.262 mm2, respectively, for the mean length, width, and area of the FO. The shape of foramen was typically ovale in most of the skulls (56.70%) with some bony variations such as spine, tubercles, bony bridge/bar, and confluence. CONCLUSION: Such variants in the FO could interfere with transcutaneous needle placement into the FO or distort anatomic relationships during approaches to the cranial base.