Pre-clinical evaluation of 99mTc-labeled chalcone derivative for amyloid-ß imaging post-head trauma.

Aß42 plaque formation is one of the preliminary pathologic events that occur post traumatic brain injury (TBI) which is also among the most noteworthy hallmarks of AD. Their pre symptomatic detection is therefore vital for better disease management. Chalcone-picolinic acid chelator derivative, 6-({[(6-carboxypyridin-2-yl)methyl](2-{4-[(2E)-3-[4-(dimethyl amino)phenyl]prop-2-enoyl]phenoxy}ethyl)amino}methyl)pyridine-2-carboxylic acid, Py-chal was synthesized to selectively identify amyloid plaques formed post head trauma using SPECT imaging by stable complexation to 99mTc with > 97% efficiency without compromising amyloid specificity. The binding potential of the Py-chal ligand to amyloid plaques remained high as confirmed by in vitro binding assay and photophysical spectra. Further, the Py-chal complex stained amyloid aggregates in the brain sections of rmTBI mice model. In vivo scintigraphy in TBI mice model displayed high uptake followed by high retention while the healthy rabbits displayed higher brain uptake followed by a rapid washout attributed to absence of amyloid plaques. Higher uptake in brain of TBI model was also confirmed by ex vivo biodistribution analysis wherein brain uptake of 3.38 ± 0.2% ID/g at 2 min p.i. was observed for TBI mice model. This was followed by prolonged retention and more than twofold higher activity as compared to sham mice brain. This preliminary data suggests the specificity of the radiotracer for amyloid detection post head trauma and applicability of 99mTc labeled Py-chal complex for TBI-induced ß-amyloid SPECT imaging.

Nanoapatite-Loaded κ-Carrageenan/Poly(vinyl alcohol)-Based Injectable Cryogel for Hemostasis and Wound Healing.

Immediate control of excessive bleeding and prevention of infections are of utmost importance in the management of wounds. Cryogels have emerged as promising materials for the rapid release of medication and achieving hemostasis. However, their quick release properties pose the challenge of exposing patients to high concentrations of drugs. In this study, hybrid nanocomposites were developed to address this issue by combining poly(vinyl alcohol) and κ-carrageenan with whitlockite nanoapatite (WNA) particles and ciprofloxacin, aiming to achieve rapid hemostasis and sustained antibacterial effects. A physically cross-linked cryogel was obtained by subjecting a blend of poly(vinyl alcohol) and κ-carrageenan to successive freezing-thawing cycles, followed by the addition of WNA. Furthermore, ciprofloxacin was introduced into the cryogel matrix for subsequent evaluation of its wound healing properties. The resulting gel system exhibited a 3D microporous structure and demonstrated excellent swelling, low cytotoxicity, and outstanding mechanical properties. These characteristics were evaluated through analytical and rheological experiments. The nanocomposite cryogel with 4% whitlockite showed extended drug release of 71.21 ± 3.5% over 21 days and antibacterial activity with a considerable growth inhibition zone (4.19 ± 3.55 cm). Experiments on a rat model demonstrated a rapid hemostasis property of cryogels within an average of 83 ± 4 s and accelerated the process of wound healing with 96.34% contraction compared to the standard, which exhibited only ∼78% after 14 days. The histopathological analysis revealed that the process of epidermal re-epithelialization took around 14 days following the skin incision. The cryogel loaded with WNAs and ciprofloxacin holds great potential for strategic utilization in wound management applications as an effective material for hemostasis and anti-infection purposes.

2D QSAR, Design, and in Silico Analysis of Thiophene-Tethered Lactam Derivatives as Antimicrobial Agents.

BACKGROUND: A very high rate of resistance causes health-care-associated and community-acquired infections. E. coli is one of the nine pathogens of highest concern to most of the antibiotics and other class of antimicrobials. OBJECTIVE: The objective of the present study is to develop novel thiophene derivatives using 2D QSAR and in silico approach for E. coli resistance. METHODS: Substituted thiophene series reported by Nishu Singla et al., were taken for QSAR analysis. From the results, a set of 15 new compounds were designed. A complete in silico analysis has been done using PADEL, Autodock vina, Swiss ADME, Protox II software. RESULTS: The designed compounds obey the Lipinski's rule of five and were known to have excellent inhibitory action (pIC50 values -0.87 to -1.46) which is similar to the most active compound of the data set (pIC50 -0.69) taken for the study. The bioavailability score (0.65) with no toxicity representing that the designed compounds are suitable for oral administration. CONCLUSION: The designed compounds are inactive for mutagenicity and cytotoxicity and ADMET studies states that these molecules are likely to be orally bioavailable and could be easily transported, diffused, and absorbed. So, the designed compounds will definitely serve as a lead antibacterial agent for E. coli resistance.

Antiferromagnetically coupled double perovskite as an efficient and robust catalyst for visible light driven water splitting at neutral pH.

Green and sustainable energy production through renewable sources is an enormously exciting field of research. Herein, we report an A-site lanthanum doped oxygen excess ruthenate (predominantly Ru5+-ions) double perovskite system, CaLaScRuO6+δ (CLSR), as an excellent photocatalyst for water splitting. The well characterized polycrystalline compound shows canted antiferromagnetic (AFM) behavior due to the existence of disordered Ru-ions at the B-site. Based on density functional theory + U (Hubbard U) calculations, we have estimated various magnetic exchange interactions and found that the ground state is antiferromagnetic in nature which is in perfect agreement with our experimental results. Detailed analysis of the electronic structure further reveals that the present system belongs to the family of charge transfer semiconductors with an energy gap of ∼0.45 eV. Finally, the material is found to proficiently work for the oxygen evolution reaction (OER) via visible-light driven water splitting at neutral pH in an ecofriendly manner.

Effectiveness and Safety of E-aminocaproic Acid in Overall and Less-Invasive Cardiac Surgeries.

OBJECTIVES: To examine E-aminocaproic acid effectiveness in reducing transfusion requirements in overall and less-invasive cardiac surgery, and to assess its safety. DESIGN: Retrospective cohort study. SETTING: Single-center tertiary academic medical center. PARTICIPANTS: A total of 19,111 adult patients who underwent elective surgery requiring cardiopulmonary bypass from January 1, 2008, through December 31, 2016. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Propensity matching was used to create well-balanced groups and separately compare both overall cohort and less-invasive surgery with and without E-aminocaproic acid. Supplementary zero-inflated negative binomial regression analysis was used because outcome data were zero-inflated. Effectiveness was assessed by transfusion requirements, and safety by comparison of in-hospital outcomes. In the overall cohort, patients receiving E-aminocaproic acid received fewer red blood cells postoperatively and fewer intra- and postoperativel blood products. In a less-invasive cohort, there was no significant difference in red blood cell transfusion either intra- or postoperatively, but the E-aminocaproic group received fewer intra- and postoperative platelets, intraoperative cryoprecipitate, and postoperative plasma. There were no significant differences for in-hospital outcomes in both less-invasive and overall cohorts. CONCLUSIONS: The reduction of postoperative red blood cell requirement observed when analyzing the overall cohort did not translate to less-invasive cardiac surgery in the authors' patient population; however, both overall and less-invasive cohorts had lower requirements for other blood components with E-aminocaproic acid. There was no association with major Society of thoracic surgeons (STS)-defined morbidity and mortality in both groups.

Pulmonary embolism in coronavirus disease 2019: the silent killer.

BACKGROUND: Pulmonary embolism (PE) has been identified as one of the deadliest complications of coronavirus disease 2019 (COVID-19), especially in patients admitted to the intensive care unit (ICU). Western literature reminds us of the high prevalence of PE in COVID. Here, we report a series of 13 cases of PE diagnosed and managed at our hospital. METHODS: Retrospective analysis of medical records of 13 cases of PE admitted at our hospital from February 1, 2020, to September 31, 2020, were done. Their clinical, laboratory, and radiologic data were assessed in detail. RESULTS: Computed tomography pulmonary arteriography was used to make the diagnosis in eight patients (61.53%), and clinical findings with corroborative ultrasound and laboratory parameters were used to label PE in five patients (38.46%). Five patients were hemodynamically unstable, requiring thrombolysis with recombinant tissue plasminogen activator, and four patients (30.76%) suffered a fatal outcome. CONCLUSION: COVID-19 is a highly prothrombotic state, and all physicians should keep a high vigilance for PE. All hospitalized patients with COVID-19, especially those admitted in ICU, should be on prophylactic anticoagulation and, if there is any worsening, should be started on therapeutic regimen. Patients at the time of discharge should be switched to oral anticoagulation, which should be continued for at least 3-6 months.

Triggering Lewis Acidic Nature through the Variation of Coordination Environment of Cd-Centers in 2D-Coordination Polymers.

The rational design and successful synthesis of novel functional metal-organic frameworks relies on careful selection of metals and versatile organic ligands. A newly designed pyrazole-based dicarboxylate ligand, 5-(3,5-dimethyl-1H-pyrazol-1-yl) 1,3-benzenedicarboxylic acid (H2L), was utilized to obtain two new Cd-based coordination polymers I [Cd(L)(H2O)]·H2O and II [Cd(L)] under similar reaction conditions via solvothermal strategy. Single-crystal X-ray data confirmed that compound I exhibits a two-dimensional (2D) skeleton comprising pentagonal bipyramidal Cd-ions and an organic ligand moiety. Compound II has also formed a two-dimensional layer arrangement with the connectivity between trigonal bipyramidal Cd-ions and the organic ligand. Topological analysis revealed that compound I has formed unique 43.63 net topology while compound II has displayed a 44.62 sql net topology with 2D frameworks. The Lewis acidic nature of both I and II containing a Cd2+ metal center has been correlated with the coordination number through dye adsorption-desorption and catalysis studies. The selective adsorption of anionic dye and the extent of adsorption are interrelated with the Cd-ion geometry. For the first time, the role of coordinated water molecule has been analyzed through heterogeneous catalysis reaction (i.e., cyanosilylation) with Cd-based 2D-coordination polymers (CPs). The plausible mechanisms have been proposed to explain the subsequent role of coordination number and environment in CPs.

Colossal Dielectric Responses from the Wide Band Gap 2D-Semiconducting Amine Templated Hybrid Framework Materials.

Two unprecedented organic amine templated silver organophosphonate hybrid solids have been synthesized hydrothermally by varying the molar ratio of the reactants. Both of the compounds consist of novel tetra- and penta-nuclear silver phosphonate basic building units. The dielectric constants are extremely large due to the charge separation of anionic metal phosphonate frameworks and cationic templated piperazine moieties in the compounds, as found for the first time in a hybrid organophosphate family. The conductivity and UV-visible absorption studies provide strong evidence about the semiconducting nature of the present compounds.

Streptococcus pneumoniae in the heart subvert the host response through biofilm-mediated resident macrophage killing.

For over 130 years, invasive pneumococcal disease has been associated with the presence of extracellular planktonic pneumococci, i.e. diplococci or short chains in affected tissues. Herein, we show that Streptococcus pneumoniae that invade the myocardium instead replicate within cellular vesicles and transition into non-purulent biofilms. Pneumococci within mature cardiac microlesions exhibited salient biofilm features including intrinsic resistance to antibiotic killing and the presence of an extracellular matrix. Dual RNA-seq and subsequent principal component analyses of heart- and blood-isolated pneumococci confirmed the biofilm phenotype in vivo and revealed stark anatomical site-specific differences in virulence gene expression; the latter having major implications on future vaccine antigen selection. Our RNA-seq approach also identified three genomic islands as exclusively expressed in vivo. Deletion of one such island, Region of Diversity 12, resulted in a biofilm-deficient and highly inflammogenic phenotype within the heart; indicating a possible link between the biofilm phenotype and a dampened host-response. We subsequently determined that biofilm pneumococci released greater amounts of the toxin pneumolysin than did planktonic or RD12 deficient pneumococci. This allowed heart-invaded wildtype pneumococci to kill resident cardiac macrophages and subsequently subvert cytokine/chemokine production and neutrophil infiltration into the myocardium. This is the first report for pneumococcal biofilm formation in an invasive disease setting. We show that biofilm pneumococci actively suppress the host response through pneumolysin-mediated immune cell killing. As such, our findings contradict the emerging notion that biofilm pneumococci are passively immunoquiescent.

Chemometric Based Identification and Validation of Specific Chemical Markers for Geographical, Seasonal and Gender Variations in Tinospora cordifolia Stem using HPLC-ESI-QTOF-MS Analysis.

INTRODUCTION: Tinospora cordifolia is a widely distributed medicinal plant used in various traditional and commercial Ayurvedic formulations. Due to the wide use of this plant it is important to know the extent of variability in the metabolite profile resulting from geographical location, season and gender. OBJECTIVE: To develop a statistical approach based on phytochemical markers for confident prediction of variations in metabolic profile and cytotoxicity due to geographical, seasonal and gender difference in T. cordifolia stem. METHODS: A HPLC-ESI-QTOF-MS method was used for the metabolite profiling of T. cordifolia stem. The data were analysed using chemometric methods including Student's t-test, ANOVA, FA/PCA and ROC curve analysis and validated for the identification of chemical variations. The bioactivity of selected samples was also tested using a cell cytotoxicity assay to assess the functional aspect of the phytochemical variability. RESULTS: The chemometric approach applied here identified marker ions for geographical locations (m/z 294.1139 and 445.2136), seasons (m/z 344.1482, 359.1501, and 373.1305) and gender (m/z 257.1380) with 100% statistical sensitivity and specificity. An in vitro cytotoxicity evaluation revealed that male T. cordifolia stem was the most effective in inhibiting the growth of cancerous cell lines. CONCLUSIONS: The developed and validated chemometric approach identified the analytical markers for phytochemical variations in unknown T. cordifolia stem samples from male or female plants and samples collected from different geographical locations and seasons. The results are supported by comparative cytotoxic activity data. Copyright © 2017 John Wiley & Sons, Ltd.

Neuraminidase A-Exposed Galactose Promotes Streptococcus pneumoniae Biofilm Formation during Colonization.

Streptococcus pneumoniae is an opportunistic pathogen that colonizes the nasopharynx. Herein we show that carbon availability is distinct between the nasopharynx and bloodstream of adult humans: glucose is absent from the nasopharynx, whereas galactose is abundant. We demonstrate that pneumococcal neuraminidase A (NanA), which cleaves terminal sialic acid residues from host glycoproteins, exposed galactose on the surface of septal epithelial cells, thereby increasing its availability during colonization. We observed that S. pneumoniae mutants deficient in NanA and ß-galactosidase A (BgaA) failed to form biofilms in vivo despite normal biofilm-forming abilities in vitro Subsequently, we observed that glucose, sucrose, and fructose were inhibitory for biofilm formation, whereas galactose, lactose, and low concentrations of sialic acid were permissive. Together these findings suggested that the genes involved in biofilm formation were under some form of carbon catabolite repression (CCR), a regulatory network in which genes involved in the uptake and metabolism of less-preferred sugars are silenced during growth with preferred sugars. Supporting this notion, we observed that a mutant deficient in pyruvate oxidase, which converts pyruvate to acetyl-phosphate under non-CCR-inducing growth conditions, was unable to form biofilms. Subsequent comparative transcriptome sequencing (RNA-seq) analyses of planktonic and biofilm-grown pneumococci showed that metabolic pathways involving the conversion of pyruvate to acetyl-phosphate and subsequently leading to fatty acid biosynthesis were consistently upregulated during diverse biofilm growth conditions. We conclude that carbon availability in the nasopharynx impacts pneumococcal biofilm formation in vivo Additionally, biofilm formation involves metabolic pathways not previously appreciated to play an important role.

Analysis of phytochemical variations in dioecious Tinospora cordifolia stems using HPLC/QTOF MS/MS and UPLC/QqQLIT -MS/MS.

INTRODUCTION: The stem of dioecious Tinospora cordifolia (Menispermaceae) is a commonly used traditional Ayurvedic medicine in India having several therapeutic properties. OBJECTIVE: To develop and validate LC-MS methods for the identification and simultaneous quantitation of various secondary metabolites and to study metabolomic variations in the stem of male and female plants. METHODS: Ethanolic extract of stems were analysed by HPLC/ESI-QTOF-MS/MS for rapid screening of bioactive phytochemicals. High resolution MS and MS/MS in positive ESI mode were used for structural investigation of secondary metabolites. An UPLC/ESI-QqQ(LIT) -MS/MS method in MRM mode was developed and validated for the simultaneous quantitation of five bioactive alkaloids. RESULTS: Identification and characterisation of 36 metabolites including alkaloids, sesquiterpenes and phytoecdysteroids were performed using LC-MS and MS/MS techniques. The bioactive alkaloids such as jatrorrhizine, magnoflorine, isocorydine, palmatine and tetrahydropalmatine were successfully quantified in male and female plants. The mean abundances of magnoflorine jatrorrhizine, and oblongine were significantly (P < 0.05) higher in male plants while mean abundances of tetrahydropalmatine, norcoclaurine, and reticuline were significantly (P < 0.05) higher in female plants. CONCLUSIONS: Phytochemicals in the stem of male and female Tinospora cordifolia showed significant qualitative and quantitative variations. LC-MS and MS/MS methods can be used to differentiate between male and female plants based on their chemical profiles and quantities of the marker bioactive alkaloids. This chemical composition difference was also evident during vegetative stage when there were no male and female flowers.

Reversibility of superconducting nb weak links driven by the proximity effect in a quantum interference device.

We demonstrate the role of the proximity effect in the thermal hysteresis of superconducting constrictions. From the analysis of successive thermal instabilities in the transport characteristics of micron-size superconducting quantum interference devices with a well-controlled geometry, we obtain a complete picture of the different thermal regimes. These determine whether or not the junctions are hysteretic. Below the superconductor critical temperature, the critical current switches from a classical weak-link behavior to one driven by the proximity effect. The associated small amplitude of the critical current makes it robust with respect to the heat generation by phase slips, leading to a nonhysteretic behavior.

Limitations of Current AHA Guidelines and Proposal of New Guidelines for the Preparticipation Examination of Athletes.

OBJECTIVE: To examine the prevalence of athletes who screen positive with the preparticipation examination guidelines from the American Heart Association, the AHA 12-elements, in combination with 3 screening electrocardiogram (ECG) criteria. DESIGN: Observational cross-sectional study. SETTING: Stanford University Sports Medicine Clinic. PARTICIPANTS: Total of 1596 participants, including 297 (167 male; mean age, 16.2 years) high school athletes, 1016 (541 male; mean age, 18.8 years) collegiate athletes, and 283 (mean age, 26.3 years) male professional athletes. MAIN OUTCOME MEASURES: Athletes were screened using the 8 personal and family history questions from the AHA 12-elements. Electrocardiograms were obtained for all participants and interpreted using Seattle criteria, Stanford criteria, and European Society of Cardiology (ESC) recommendations. RESULTS: Approximately one-quarter of all athletes (23.8%) had at least 1 positive response to the AHA personal and family history elements. High school and college athletes had similar rates of having at least 1 positive response (25.9% vs 27.4%), whereas professional athletes had a significantly lower rate of having at least 1 positive response (8.8%, P < 0.05). Females reported more episodes of unexplained syncope (11.4% vs 7.5%, P = 0.017) and excessive exertional dyspnea with exercise (11.1% vs 6.1%, P = 0.001) than males. High school athletes had more positive responses to the family history elements when compared with college athletes (P < 0.05). The percentage of athletes who had an abnormal ECG varied between Seattle criteria (6.0%), Stanford criteria (8.8%), and ESC recommendations (26.8%). CONCLUSIONS: Many athletes screen positive under current screening recommendations, and ECG results vary widely by interpretation criteria. CLINICAL RELEVANCE: In a patient population without any adverse cardiovascular events, the currently recommended AHA 12-elements have an unacceptably high rate of false positives. Newer screening guidelines are needed, with fewer false positives and evidence-based updates.

Extensive duplication of the Wolbachia DNA in chromosome four of Drosophila ananassae.

BACKGROUND: Lateral gene transfer (LGT) from bacterial Wolbachia endosymbionts has been detected in ~20% of arthropod and nematode genome sequencing projects. Many of these transfers are large and contain a substantial part of the Wolbachia genome. RESULTS: Here, we re-sequenced three D. ananassae genomes from Asia and the Pacific that contain large LGTs from Wolbachia. We find that multiple copies of the Wolbachia genome are transferred to the Drosophila nuclear genome in all three lines. In the D. ananassae line from Indonesia, the copies of Wolbachia DNA in the nuclear genome are nearly identical in size and sequence yielding an even coverage of mapped reads over the Wolbachia genome. In contrast, the D. ananassae lines from Hawaii and India show an uneven coverage of mapped reads over the Wolbachia genome suggesting that different parts of these LGTs are present in different copy numbers. In the Hawaii line, we find that this LGT is underrepresented in third instar larvae indicative of being heterochromatic. Fluorescence in situ hybridization of mitotic chromosomes confirms that the LGT in the Hawaii line is heterochromatic and represents ~20% of the sequence on chromosome 4 (dot chromosome, Muller element F). CONCLUSIONS: This collection of related lines contain large lateral gene transfers composed of multiple Wolbachia genomes that constitute >2% of the D. ananassae genome (~5 Mbp) and partially explain the abnormally large size of chromosome 4 in D. ananassae.

Rapid transcriptome sequencing of an invasive pest, the brown marmorated stink bug Halyomorpha halys.

BACKGROUND: Halyomorpha halys (Stål) (Insecta:Hemiptera;Pentatomidae), commonly known as the Brown Marmorated Stink Bug (BMSB), is an invasive pest of the mid-Atlantic region of the United States, causing economically important damage to a wide range of crops. Native to Asia, BMSB was first observed in Allentown, PA, USA, in 1996, and this pest is now well-established throughout the US mid-Atlantic region and beyond. In addition to the serious threat BMSB poses to agriculture, BMSB has become a nuisance to homeowners, invading home gardens and congregating in large numbers in human-made structures, including homes, to overwinter. Despite its significance as an agricultural pest with limited control options, only 100 bp of BMSB sequence data was available in public databases when this project began. RESULTS: Transcriptome sequencing was undertaken to provide a molecular resource to the research community to inform the development of pest control strategies and to provide molecular data for population genetics studies of BMSB. Using normalized, strand-specific libraries, we sequenced pools of all BMSB life stages on the Illumina HiSeq. Trinity was used to assemble 200,000 putative transcripts in >100,000 components. A novel bioinformatic method that analyzed the strand-specificity of the data reduced this to 53,071 putative transcripts from 18,573 components. By integrating multiple other data types, we narrowed this further to 13,211 representative transcripts. CONCLUSIONS: Bacterial endosymbiont genes were identified in this dataset, some of which have a copy number consistent with being lateral gene transfers between endosymbiont genomes and Hemiptera, including ankyrin-repeat related proteins, lysozyme, and mannanase. Such genes and endosymbionts may provide novel targets for BMSB-specific biocontrol. This study demonstrates the utility of strand-specific sequencing in generating shotgun transcriptomes and that rapid sequencing shotgun transcriptomes is possible without the need for extensive inbreeding to generate homozygous lines. Such sequencing can provide a rapid response to pest invasions similar to that already described for disease epidemiology.

Comparison of three ECG criteria for athlete pre-participation screening.

UNLABELLED: Controversy regarding adding the ECG to the evaluation of young athletes centers on the implications of false positives. Several guidelines have been published with recommendations for criteria to distinguish between ECG manifestations of training and markers of risk for cardiovascular (CV) sudden death. With an athlete dataset negative of any CV related abnormalities on follow-up, we applied three athlete screening criteria to identify the one with the lowest rate of abnormal variants. METHODS: High school, college, and professional athletes underwent 12L ECGs as part of routine physicals. All ECGs were recorded and processed using CardeaScreen (Seattle, WA). The European (2010), Stanford (2011), and Seattle criteria (2013) were applied. RESULTS: From March 2011 to February 2013 1417 ECGs were collected. Mean age was 20±4years (14-35years), 36% female, 38.5% non-white (307 high school, 836 college and 284 professional). Rate of abnormal variants differed by criteria, predominately due to variation in interval thresholds for QT interval and QRS duration. There was a four-fold difference in abnormal variants between European and Seattle criteria (26% v 6%). CONCLUSION: The Seattle criterion was the most conservative resulting in 78% fewer abnormal variants than the European criteria. Variation was most evident with thresholds for QT prolongation, short QT interval, and intraventricular conduction delay. Continued research is needed to further understand normal training related adaptations and to improve modern ECG screening criteria for athletes.

Influence of skin-to-muscle and muscle-to-bone thickness on depth of needle penetration in adults at the deltoid intramuscular injection site.

BACKGROUND: THE OBJECTIVES OF THE STUDY WERE TO ESTIMATE THE FOLLOWING IN ADULTS OF INDIAN ORIGIN: a) Gender and side differences in the skin-to-muscle (SM) and muscle-to-bone thickness (MB) at the deltoid intramuscular injection site; b) Correlation of SM thickness with the BMI, age and gender; c) The prevalence of under and over-penetration assuming a standard needle length of 25 mm and following prescribed guidelines for IM injection. METHODS: The SM, MB and skin-to-bone (SB) thicknesses were bilaterally estimated in two hundred adult Indian subjects (100 male and 100 female) using an ultrasound probe at a pre-determined point on the upper arms of the subjects. The BMI of each subject was calculated. The unpaired sample 't' test and paired 't' test were used to analyse differences between groups. Pearson's correlation coefficient was used in correlation analysis and suitable linear regression equations were generated. RESULTS: Females had a significantly higher SM thickness and lower MB thickness. The SM thickness was significantly greater on the left side, while the SB and MB thickness were significantly greater on the right. Multiple linear regression equations for both the dominant and non-dominant arms had good model fit properties. Under-penetration would have occurred in 2 (1%) subjects while over-penetration would have occurred in 50% of the subjects. CONCLUSION: Over-penetration of deltoid IM injections is likely to be more prevalent as compared to under-penetration. Therefore, the technique of IM injection needs to be modified based on the body type of the individual patient.