The effect of bubble surface charge on phonophoresis: Implication in transdermal piroxicam delivery

It is over several decades that ultrasound is used to enhance the transdermal drug delivery (phonphoresis). The mechanism of the enhancement is not fully understood and the ability of ultrasound on the enhancement for some drugs is unclear. The effect of continuous wave 870 KHz ultrasound at intensity of 1 W/cm2 for 15 minutes on transdermal absorption of piroxicam from solution and gel formulations in hairless rat skin was studied. Exposure to ultrasound increased the rate of diffusion from gel and solution of piroxicam to 10 and 3 times higher than that in skins not exposed to ultrasound. We strongly believe that the lower diffusion of piroxicam from the solution is caused by extra-bubbles generated by ultrasound. It can be suggested that cavitation activity and its negative surface charges play a dominant rule in phonophoresis. Copyright © 2006 by Razi Institute for Drug Research (RIDR)

Evaluation of influencing factors on the radiation dose of hospitalized neonates: Maturity status and type of disease

Context: Premature neonates have multiple medical and surgical problems; therefore, hospitalization and imaging are required. Recently there has been too much concern about the long-term effects of radiation in neonates. In this survey, we assessed the frequency of imaging and radiation dose in neonates hospitalized in neonatal intensive care unit (NICU) in our University-affiliated hospital. Materials and methods: This was a retrospective cross-sectional study conducted during a year (2019–2020) on 291 neonates. The information has been gathered from Health Information System and picture archiving and communication system, and analyzed with SPSS version 22. Results: 291 neonates were included in the study, from which 175 (60%) neonates were preterm and 116 (40%) neonates were term neonates. The mean gestational age (GA) was 35.5 weeks and the mean hospital admission duration was 15.8 days. The mean number of portable and non-portable imaging procedures was 5.13 and 0.62 for preterm and term neonates, respectively. There is a statistically significant relationship between gastrointestinal disease and the number of abdominal X-rays. There is also a statistically significant relationship between acute respiratory distress syndrome (ARDS) and chest X-rays; there is no statistically significant relationship between pneumonia and the number of chest X-rays in the hospital course. The mean accumulation effective doses in preterm and term neonates in-hospital course were 0.549 and 0.498 mSv, respectively. Discussion: The neonates in NICU are more susceptible to radiation hazards due to numerous imaging than other neonates. Portable imaging is eight times more dosing than non-portable imaging, so due to the scattered radiation from portable devices, the actual radiation dose may be higher than what we estimated. No brain CT scan was done for the neonates with convulsion because of using safer and more valuable modalities; so we could recommend radiologists and pediatrics to use substitute modalities like sonography and MRI instead of CT scan and X-rays

Shoot tip regeneration and optimization of Agrobacterium tumefaciens-mediated transformation of Broccoli (Brassica oleracea var. italica) cv. Green Marvel

A protocol of plant regeneration from shoot tips and optimization of Agrobacterium tumefaciens-mediated transformation of broccoli (Brassica oleracea var. italica) cv. Green Marvel have been developed. Shoot tip response was assessed on Murashige and Skoog (MS) medium supplemented with different concentrations of zeatin. The highest regeneration with a maximum of 13 shoots per explant was obtained on MS medium containing 1.5 mg l-1 zeatin. Primary selection of putative transformed explants was performed on the optimized regeneration medium (MS medium containing 1.5 mg l-1 zeatin and 80 mg l-1 kanamycin) for 60 days. The effects of preculture, acetosyringone and growth of bacterial culture were studied. Explants precultured on callus induction medium for 4 days prior to inoculation with A. tumefaciens with 200 lM acetosyringone resulted in improved transformation frequency. The Agrobacterium culture dilution of 1:5 and inoculation time of 30 min increased the efficiency of transformation of shoot tip explants. The results also indicated that 150 mg l-1 ampicillin alone was adequate to eradicate Agrobacterium growth in the SRM incorporated with the respective minimum inhibitory concentration of 80 mg l-1 kanamycin. The polymerase chain reaction (PCR) and Southern blot assays confirmed the transgenic status of the broccoli cv. Green Marvel regenerants. A transformation efficiency of 5 % was achieved based on the positive PCR results using the optimized procedure. The expression of luciferase reporter gene in the transformed cells and the transcription of AtHSP101 using RT-PCR further confirmed the transgenic status of the regenerated plants

Investigation of brain iron in anorexia nervosa, a quantitative susceptibility mapping study

Abstract Background Anorexia nervosa (AN) is a potentially fatal psychiatric condition, associated with structural brain changes such as gray matter volume loss. The pathophysiological mechanisms for these changes are not yet fully understood. Iron is a crucial element in the development and function of the brain. Considering the systemic alterations in iron homeostasis in AN, we hypothesized that brain iron would be altered as a possible factor associated with structural brain changes in AN. Methods In this study, we used quantitative susceptibility mapping (QSM) magnetic resonance imaging to investigate brain iron in current AN (c-AN) and weight-restored AN compared with healthy individuals. Whole-brain voxel wise comparison was used to probe areas with possible group differences. Further, the thalamus, caudate nucleus, putamen, nucleus accumbens, hippocampus, and amygdala were selected as the regions of interest (ROIs) for ROI-based comparison of mean QSM values. Results Whole-brain voxel-wise and ROI-based comparison of QSM did not reveal any differences between groups. Exploratory analyses revealed a correlation between higher regional QSM (higher iron) and lower body mass index, higher illness severity, longer illness duration, and younger age at onset in the c-AN group. Conclusions This study did not find evidence of altered brain iron in AN compared to healthy individuals. However, the correlations between clinical variables and QSM suggest a link between brain iron and weight status or biological processes in AN, which warrants further investigation

DECT evaluation of noncalc fied coronary artery plaque

Purpose: Composition of the coronary artery plaque is known to have critical role in heart attack. While calcified plaque can easily be diagnosed by conventional CT, it fails to distinguish between fibrous and lipid rich plaques. In the present paper, the authors discuss the experimental techniques and obtain a numerical algorithm by which the electron density (rho(e)) and the effective atomic number (Z(eff)) can be obtained from the dual energy computed tomography (DECT) data. The idea is to use this inversion method to characterize and distinguish between the lipid and fibrous coronary artery plaques. Methods: For the purpose of calibration of the CT machine, the authors prepare aqueous samples whose calculated values of (rho(e), Z(eff)) lie in the range of (2.65 x 10(23) <= rho(e) <= 3.64 x 10(23)/cm(3)) and (6.80 <= Z(eff) <= 8.90). The authors fill the phantom with these known samples and experimentally determine HU(V-1) and HU(V-2), with V-1,V-2 = 100 and 140 kVp, for the same pixels and thus determine the coefficients of inversion that allow us to determine (rho(e), Z(eff)) from the DECT data. The HU(100) and HU(140) for the coronary artery plaque are obtained by filling the channel of the coronary artery with a viscous solution of methyl cellulose in water, containing 2% contrast. These (rho(e), Z(eff)) values of the coronary artery plaque are used for their characterization on the basis of theoretical models of atomic compositions of the plaque materials. These results are compared with histopathological report. Results: The authors find that the calibration gives Pc with an accuracy of 3.5% while Z(eff) is found within 1% of the actual value, the confidence being 95%. The HU(100) and HU(140) are found to be considerably different for the same plaque at the same position and there is a linear trend between these two HU values. It is noted that pure lipid type plaques are practically nonexistent, and microcalcification, as observed in histopathology, has to be taken into account to explain the nature of the observed (rho(e), Z(eff)) data. This also enables us to judge the composition of the plaque in terms of basic model which considers the plaque to be composed of fibres, lipids, and microcalcification. Conclusions: This simple and reliable method has the potential as an effective modality to investigate the composition of noncalcified coronary artery plaques and thus help in their characterization. In this inversion method, (rho(e), Z(eff)) of the scanned sample can be found by eliminating the effects of the CT machine and also by ensuring that the determination of the two unknowns (rho(e), Z(eff)) does not interfere with each other and the nature of the plaque can be identified in terms of a three component model. (C) 2015 American Association of Physicists in Medicine

Imaging joint infections using D-methyl-11C-methionine PET/MRI: initial experience in humans.

PurposeNon-invasive imaging is a key clinical tool for detection and treatment monitoring of infections. Existing clinical imaging techniques are frequently unable to distinguish infection from tumors or sterile inflammation. This challenge is well-illustrated by prosthetic joint infections that often complicate joint replacements. D-methyl-11C-methionine (D-11C-Met) is a new bacteria-specific PET radiotracer, based on an amino acid D-enantiomer, that is rapidly incorporated into the bacterial cell wall. In this manuscript, we describe the biodistribution, radiation dosimetry, and initial human experience using D-11C-Met in patients with suspected prosthetic joint infections.Methods614.5 ± 100.2&nbsp;MBq of D-11C-Met was synthesized using an automated in-loop radiosynthesis method and administered to six healthy volunteers and five patients with suspected prosthetic joint infection, who were studied by PET/MRI. Time-activity curves were used to calculate residence times for each source organ. Absorbed doses to each organ and body effective doses were calculated using OLINDA/EXM 1.1 with both ICRP 60 and ICRP 103 tissue weighting factors. SUVmax and SUVpeak were calculated for volumes of interest (VOIs) in joints with suspected infection, the unaffected contralateral joint, blood pool, and soft tissue background. A two-tissue compartment model was used for kinetic modeling.ResultsD-11C-Met was well tolerated in all subjects. The tracer showed clearance from both urinary (rapid) and hepatobiliary (slow) pathways as well as low effective doses. Moreover, minimal background was observed in both organs with resident micro-flora and target organs, such as the spine and musculoskeletal system. Additionally, D-11C-Met showed increased focal uptake in areas of suspected infection, demonstrated by a significantly higher SUVmax and SUVpeak calculated from VOIs of joints with suspected infections compared to the contralateral joints, blood pool, and background (P &lt; 0.01). Furthermore, higher distribution volume and binding potential were observed in suspected infections compared to the unaffected joints.ConclusionD-11C-Met has a favorable radiation profile, minimal background uptake, and fast urinary extraction. Furthermore, D-11C-Met showed increased uptake in areas of suspected infection, making this a promising approach. Validation in larger clinical trials with a rigorous gold standard is still required