Antiarrhythmic potential of chloroquine: new use for an old drug

Amiodarone and chlorpromazine are phospholipase inhibitors which produce cytoplasmic inclusion bodies and have important electrophysiologic properties. Chloroquine also inhibits phospholipase activity, resulting in similar inclusion bodies, but electrophysiologic information about this drug is lacking. In this study, the cellular electrophysiologic effects of two doses of chloroquine were examined in sheep Purkinje fibres and ventricular muscle cells. Both concentrations produced a significant reduction in maximum velocity of upstroke of the action potential and prolongation of the action potential duration and refractory period in Purkinje fibres. These effects were observed in the absence of significant changes in threshold of stimulation or action potential amplitude and were partially reversible following washout of the lower drug concentration. In addition to these experimental data, clinical evidence of antiarrhythmic action was determined by administering 500 mg chloroquine daily over nine weeks to six subjects with frequent asymptomatic ventricular premature complexes. In four patients there was a reduction in ventricular ectopy, which recurred when the drug was discontinued, while a fifth patient reverted to sinus rhythm from atrial fibrillation previously resistant to other antiarrhythmic medication. Thus, chloroquine has important electrophysiologic properties. The underlying mechanism of this action remains unproven at the present time.     

Hepatic artery stenosis after liver transplant, managed with percutaneous angioplasty and stent placement.

Hepatic artery stenosis is a recognized vascular complication of orthotopic liver transplant that carries significant morbidity and mortality. The authors present a case of hepatic artery stenosis in a 50-year-old female successfully treated with balloon angioplasty and stent. This case report highlights the importance of percutaneous intervention as a preferred treatment option in patients with hepatic artery stenosis post-orthotopic liver transplant.     

Ultrastructural changes of ischemic injury due to coronary artery occlusion in the porcine heart

Using the ultrastructural criteria established by Schaper et al. 1979 [27] for distinguishing between different degrees of ischemic change in dog myocardium, slight ischemic changes are observed in the pig suboendocardium as early as 1 min after occlusion of the LAD artery. Moderate change throughout the thickness of the myocardium is seen after 6 to 12 min of ischemia and continues to be found up until 20 min after commencement of the ischemic period. 20 to 30 min ischemia produces severe ischemic damage and more than 30 min leads to irreversible damage. The changes are uniform at all stages of ischemia and there is no evidence of a transmural gradient of ultrastructural damage. Of particular interest in the early part of the ischemic period is the observation of ultrastructural changes in the subendocardial specialized conducting tissue. In these specialized cells, although morphological features consistent with slight and moderate ischemia are found as early as 1 to 2 min after occlusion, spontaneous recovery occurs and is complete by 15 min. This biphasic time course parallels the electro-physiological changes known to occur in ischemic Purkinje fibres.     

Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) joint consensus statement for MR imaging of placenta accreta spectrum disorders

This study was conducted in order to establish the joint Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) guidelines on placenta accreta spectrum (PAS) disorders and propose strategies to standardize image acquisition, interpretation, and reporting for this condition with MRI. The published evidence-based data and the opinion of experts were combined using the RAND–UCLA Appropriateness Method and formed the basis for these consensus guidelines. The responses of the experts to questions regarding the details of patient preparation, MRI protocol, image interpretation, and reporting were collected, analyzed, and classified as “recommended” versus “not recommended” (if at least 80% consensus among experts) or uncertain (if less than 80% consensus among experts). Consensus regarding image acquisition, interpretation, and reporting was determined using the RAND–UCLA Appropriateness Method. The use of a tailored MRI protocol and standardized report was recommended. A standardized imaging protocol and reporting system ensures recognition of the salient features of PAS disorders. These consensus recommendations should be used as a guide for the evaluation of PAS disorders with MRI. • MRI is a powerful adjunct to ultrasound and provides valuable information on the topography and depth of placental invasion. • Consensus statement proposed a common lexicon to allow for uniformity in MRI acquisition, interpretation, and reporting of PAS disorders. • Seven MRI features, namely intraplacental dark T2 bands, uterine/placental bulge, loss of low T2 retroplacental line, myometrial thinning/disruption, bladder wall interruption, focal exophytic placental mass, and abnormal vasculature of the placental bed, reached consensus and are categorized as “recommended” for diagnosing PAS disorders.     

Pd nanoparticles on green support as dip-catalyst: a facile transfer hydrogenation of olefins and N-heteroarenes in water

Chemo- and regioselective hydrogenation methods using highly green sources, particularly from metal nanoparticles on plant stem as support and water, is an intensive research area, which is highly relevant to the development of green chemistry and technology in the 21^st century. Here, the synthesis and activity of a heterogeneous catalytic system (called “dip-catalyst”) for the transfer hydrogenation of a series of styrenyl, unfunctionalized olefins, quinoline and other N-heteroarenes, are presented. It consists of Pd nanoparticles (15–20 nm) anchored on bio-processed jute plant (Corchorus genus) stem as the support. Pd nanoparticles were decorated on the green support (GS) jute stem by the in situ reduction of K₂PdCl₄ in aqueous medium at 70 °C, using formic acid as the reductant. The Pd@GS was characterized using SEM, EDS, XRD, FTIR, XPS and TEM. Elemental mapping revealed uniform distribution of Pd on the cellulose matrix of the jute stem. The catalyst was successfully applied to the chemoselective transfer hydrogenation of numerous styrenyl, unfunctionalized olefins. Its high functional group tolerance was investigated during the olefins hydrogenation in water. Furthermore, Pd@GS was capable of quantitative hydrogenation to selectively produce 1,2,3,4-tetrahydroquinoline (THQ) in water using stoichiometric amounts of tetrahydroxydiboron (THDB) at 60 °C with turn over frequency (TOF) 4938 h⁻¹. This system is stable in water and displays excellent recyclability; it could be used for 32 consecutive cycles, without losing its original crystallinity or requiring replenishment.

A dip catalyst consisting of Pd nanoparticles immobilized on the surface of thin slices of jute-stem was fabricated. Its versatility as a hydrogen transfer agent for styrenyl, cyclic and unfunctionalized olefins and N-heterocycles was investigated.     

Collaborative Biomedicine in the Age of Big Data: The Case of Cancer

Biomedicine is undergoing a revolution driven by high throughput and connective computing that is transforming medical research and practice. Using oncology as an example, the speed and capacity of genomic sequencing technologies is advancing the utility of individual genetic profiles for anticipating risk and targeting therapeutics. The goal is to enable an era of “P4” medicine that will become increasingly more predictive, personalized, preemptive, and participative over time. This vision hinges on leveraging potentially innovative and disruptive technologies in medicine to accelerate discovery and to reorient clinical practice for patient-centered care. Based on a panel discussion at the Medicine 2.0 conference in Boston with representatives from the National Cancer Institute, Moffitt Cancer Center, and Stanford University School of Medicine, this paper explores how emerging sociotechnical frameworks, informatics platforms, and health-related policy can be used to encourage data liquidity and innovation. This builds on the Institute of Medicine’s vision for a “rapid learning health care system” to enable an open source, population-based approach to cancer prevention and control.     

Analysis of 55 cases of adenomatoid odontogenic tumor in an Indian population and review of literature

Background This study reviews the demographic, clinical and radiographic features of adenomatoid odontogenic tumor(AOT) diagnosed in an Indian population over 50 years and also evaluate and compare follicular AOT(F-AOT) and extra-follicular AOT(EF-AOT).Material and Methods 55 diagnosed cases of AOT from 1971-2020 were studied retrospectively. The data regarding the age, sex, location, variant of AOT, duration, clinical features, radiographic appearance, treatment and recurrence were collected and analysed.Results Of the 722 odontogenic tumors diagnosed, 7.6% were AOTs with higher prevalence of extra-follicular (67.3%) than follicular (32.7%) variant. All the tumors were intraosseous with a marked predilection for maxilla over mandible, ratio 2:1. The patients mean age was 19.8 years with slightly higher female predilection (male:female ratio - 1:1.5). The anterior region (76.4%) was more frequently affected and entire quadrant was involved in 21.8% cases. Clinically, asymptomatic, slow-growing swelling was seen in 81.8% cases with duration of 15 days to 10 years. Radiographically, AOT appeared as well-corticated radiolucent lesion. Canine was the most commonly impacted tooth. Recurrence was seen in 3 cases.Conclusions Interestingly, in this series extra-follicular was twice more common than follicular AOT. Few cases involved the entire quadrant or crossed the midline of either jaws. Key words:Adenomatoid odontogenic tumor (AOT), follicular AOT, extrafollicular AOT, Indian population, odontogenic tumor.     

Gelatin- and Papaya-Based Biodegradable and Edible Packaging Films to Counter Plastic Waste Generation

Most of the food packaging materials used in the market are petroleum-based plastics; such materials are neither biodegradable nor environmentally friendly and require years to decompose. To overcome these problems, biodegradable and edible materials are encouraged to be used because such materials degrade quickly due to the actions of bacteria, fungi, and other environmental effects. In this work, commonly available household materials such as gelatin, soy protein, corn starch, and papaya were used to prepare cost-effective lab-scale biodegradable and edible packaging film as an effective alternative to commercial plastics to reduce waste generation. Prepared films were characterized in terms of Fourier transform infrared spectroscopy (FTIR), water vapor transmission rate (WVTR), optical transparency, and tensile strength. FTIR confirmed the addition of papaya and soy protein to the gelatin backbone. WVTR of the gelatin-papaya films was recorded to be less than 50 g/m²/day. This water vapor barrier was five times better than films of pristine gelatin. The gelatin, papaya, and soy protein films exhibited transparencies of around 70% in the visible region. The tensile strength of the film was 2.44 MPa, which improved by a factor of 1.5 for the films containing papaya and soy protein. The barrier qualities of the gelatin and gelatin-papaya films maintained the properties even after going through 2000 bending cycles. From the results, it is inferred that the prepared films are ideally suitable for food encapsulation and their production on a larger scale can considerably cut down the plastic wastage.