Trimeresurus purpureomaculatus venom acetylcholinesterase has been partially purified by Sephadex G-200 gel filtration chromatography and DEAE Sephacel ion exchange chromatography. The enzyme has a mol. wt of 58,600. It was strongly inhibited by physostigmine salicylate and edrophonium chloride and exhibited substrate inhibition at high substrate concentration. The content of acetylcholinesterase in Trimeresurus purpureomaculatus venom was estimated to be much less than 0.3%.
A convenient acidimetric assay for phospholipase A using egg yolk suspension as substrate has been developed. The substrate mixture consists of 1 part egg yolk, 1 part 8.1 mM sodium deoxycholate, and 1 part 18 mM calcium chloride. Phospholipase A activity is measured by following the initial rate of pH change, which is linear between pH 8.0 and 7.75 and is proportional to enzyme concentration over a wide range. The assay is highly reproducible, with a coefficient of variation of 3%, and as sensitive as most established assays for phospholipase A. The assay uses inexpensive and easily available substrate and is simple to perform. It is particularly useful for monitoring phospholipase A activity in chromatography fractions.
1. The L-amino acid oxidase, hyaluronidase, alkaline phosphomonoesterase, protease, phosphodiesterase, acetylcholinesterase, phospholipase A and 5'-nucleotidase activities of 47 samples of venoms from all the six species of cobra (Naja), including five subspecies of Naja naja, were examined. 2. The results demonstrated interspecific differences in the venom contents of phospholipase A, acetylcholinesterase, hyaluronidase and phosphodiesterase. These differences in venom enzyme contents can be used for the differentiation of species of the genus Naja. 3. Thus, our results revealed a correlation between the enzyme composition of venom and the taxonomic status of the snake at the species level for the genus Naja.
Reverse transcription followed by real-time or quantitative polymerase chain reaction (RT-qPCR) is the gold standard for validation of results from transcriptomic profiling studies such as microarray and RNA sequencing. The current need for most studies, especially biomarker studies, is to evaluate the expression levels or fold changes of many transcripts in a large number of samples. With conventional low to medium throughput qPCR platforms, many qPCR plates would have to be run and a significant amount of RNA input per sample will be required to complete the experiments. This is particularly challenging when the size of study material (small biopsy, laser capture microdissected cells, biofluid, etc.), time, and resources are limited. A sensitive and high-throughput qPCR platform is therefore optimal for the evaluation of many transcripts in a large number of samples because the time needed to complete the entire experiment is shortened and the usage of lab consumables as well as RNA input per sample are low. Here, the methods of high-throughput RT-qPCR for the analysis of circulating microRNAs are described. Two distinctive qPCR chemistries (probe-based and intercalating dye-based) can be applied using the methods described here.
Envenomation resulted from sea snake bite is a highly lethal health hazard in Southeast Asia. Although commonly caused by sea snakes of Hydrophiinae, each species is evolutionarily distinct and thus, unveiling the toxin gene diversity within individual species is important. Applying next-generation sequencing, this study investigated the venom-gland transcriptome of Hydrophis curtus (spine-bellied sea snake) from Penang, West Malaysia. The transcriptome was de novo assembled, followed by gene annotation and sequence analyses. Transcripts with toxin annotation were only 96 in number but highly expressed, constituting 48.18% of total FPKM in the overall transcriptome. Of the 21 toxin families, three-finger toxins (3FTX) were the most abundantly expressed and functionally diverse, followed by phospholipases A2. Lh_FTX001 (short neurotoxin) and Lh_FTX013 (long neurotoxin) were the most dominant 3FTXs expressed, consistent with the pathophysiology of envenomation. Lh_FTX001 and Lh_FTX013 were variable in amino acid compositions and predicted epitopes, while Lh_FTX001 showed high sequence similarity with the short neurotoxin from Hydrophis schistosus, supporting cross-neutralization effect of Sea Snake Antivenom. Other toxins of low gene expression, for example, snake venom metalloproteinases and L-amino acid oxidases not commonly studied in sea snake venom were also identified, enriching the knowledgebase of sea snake toxins for future study.
Atrophic gastritis and intestinal metaplasia may progress to gastric malignancy. Non-invasive serum biomarkers have been extensively studied and proven to be useful as a screening tool to stratify risk and identify patients for endoscopy to detect early gastric cancer. These non-invasive biomarkers have been endorsed and recommended by many international consensus guidelines. In this letter, we reviewed the literature and evidence supporting the use of serum biomarkers as a dynamic test to monitor the status of atrophic gastritis.
A 39-year-old man presented with painless scrotal swelling for 2 months. He denied any asbestos exposure but worked with wall and ceiling plaster. Physical exam revealed a large right scrotum which transilluminated. Scrotal ultrasonography revealed a large right hydrocele and a polypoidal mass along the anterior wall of the scrotum. Magnetic resonance imaging of the abdomen and computed tomography of the chest showed no metastases. He underwent a right inguinal scrotal exploration and wide excision of tunica vaginalis and a partial epididymectomy. Pathology revealed well-differentiated papillary mesothelioma of the tunica vaginalis. The patient had an uneventful recovery.
Nanocomposite lead-free solders are gaining prominence as replacements for conventional lead-free solders such as Sn-Ag-Cu solder in the electronic packaging industry. They are fabricated by adding nanoparticles such as metallic and ceramic particles into conventional lead-free solder. It is reported that the addition of such nanoparticles could strengthen the solder matrix, refine the intermetallic compounds (IMCs) formed and suppress the growth of IMCs when the joint is subjected to different thermal conditions such as thermal aging and thermal cycling. In this paper, we first review the fundamental studies on the formation and growth of IMCs in lead-free solder joints. Subsequently, we discuss the effect of the addition of nanoparticles on IMC formation and their growth under several thermal conditions. Finally, an outlook on the future growth of research in the fabrication of nanocomposite solder is provided.
Oral anticoagulants are widely used in the treatment and prevention of both venous and arterial thromboembolism. They are classified into vitamin K anticoagulants (VKAs) and non-vitamin K antagonist oral anticoagulants (NOACs). The main advantage of NOACs over VKAs is the absence of the need for continuous monitoring. However, there are concerns about their effectiveness and safety in certain clinical situations. In this manuscript, I discussed the possibility of using optical coherence tomography angiography [OCTA] in the monitoring of the activity of NOACs. The rapid development of OCTA technology is very promising. Further research and development will extend its use beyond the realm of ophthalmology.
The use of serious games as digital medicine started in recent years as the United States Food and Drug Administration granted Class 1 or 2 device clearance to serious games or game-like technologies. This encouraging trend motivates interdisciplinary cooperation between experts in the medical sciences and the game industry because the Northern American pharmaceutical revenues have exceeded USD1 trillion globally since 2014. The potential of this lucrative business opportunity may attract fund providers and venture capitalists to support game-related research and development projects. The author elaborates his activities and experiences in the United States in FY2017/2018 as a Humphrey fellow from Malaysia. Specifically, the research and development trend of serious games for cognitive function in the academic and the game industry has positive impact on how medical doctors and practitioners in low- and middle-income countries may use or develop games as digital medicine.
Henna plant (Lawsonia inermis) is an Indian medicinal plant used in traditional medicine for the treatment of various diseases, besides its popularity as a natural dye to colour hand and hair. Research in the recent past has accumulated enormous evidence revealing henna plant to be an excellent source of antioxidants such as total phenolics. In this study, the extraction of total phenolics from henna stems was evaluated using the Folin-Ciocalteu assay. A set of single factor experiments was carried out for identifying the optimum condition of each independent variable affecting total phenolic content (TPC) extraction efficiency of henna stems, namely the solvent type, solvent concentration (v/v, %), extraction time (min) and extraction temperature (oC). Generally, high extraction yield was obtained using aqueous acetone (about 40%) as solvent and the extraction yield could further be increased using a prolonged time of 270 min and a higher incubation temperature of 55°C. Under these optimized conditions, the experimental maximum yield of TPC of 5554.15 ± 73.04 mg GAE/100 g DW was obtained.
1. The major phospholipase A2 (PLA-DE4) of the venom of Trimeresurus purpureomaculatus (shore pit viper) has been purified to electrophoretic homogeneity. 2. The isoelectric point of the purified enzyme was determined to be 4.20, and the mol. wt was 31,700 as estimated by Sephadex G-75 gel filtration chromatography; and 14,000 as estimated by SDS-polyacrylamide gel electrophoresis. The purified enzyme hydrolyzed phosphatidylcholine (PC) faster than phosphatidylethanolamine (PE), whereas phosphatidylserine (PS) was not hydrolyzed at all (PC greater than PE greater than PS =0). However, in reaction system consisted of mixtures of PC and PS, phosphatidylserine was effectively hydrolyzed by the enzyme. 4. The phospholipase A2 exhibited edema-forming activity but not hemolytic, hemorrhagic or anticoagulant activities. It was not lethal to mice at a dosage of 10 micrograms/g by i.v. route.
Genitourinary system is the second most common site of tuberculosis (TB) after pulmonary system. Tuberculosis of the prostate is a rare manifestation of genitourinary tuberculosis. It is even more uncommon if occurring in an immune-competent individual. Prostate TB is usually an incidental finding in transurethral resection of prostate (TURP). Here, we report a case of TB of the prostate in a 70-year-old man who had benign prostatic hyperplasia for two years. TB was diagnosed incidentally post-TURP. In this report, we also discuss additional tests which may help in establishing the diagnosis of genitourinary tuberculosis.
In Malaysia, incidence of Wilms’ Tumor (WT) is rare, with only 8 cases reported over four years according to the Malaysia Cancer Registry Report (2012-2016). Reports of spontaneous rupture of WT are scarce and the commonest presentation of this entity is a palpable mass in the abdomen. Herein, we report on the unusual presentation of an 11-year-old boy with typical symptoms of acute appendicitis. The child was subjected to an initial open appendicectomy and diagnosed intra-operatively with a right sided ruptured renal mass. Subsequent investigation leading to the diagnosis of a ruptured Wilms’ tumor and its treatment is discussed in this case presentation.
Inferior vena cava agenesis (IVCA) is an uncommon congenital anomaly which was first described in the seventeenth century. The detection of such an anomaly is often incidental and patients are asymptomatic until the third to fourth decade of life. Due to the scarcity of these cases, there is no consensus on the subsequent treatment and surveillance of incidental asymptomatic IVC anomalies. Herein, we report on a young male with incidental findings of suprarenal IVC agenesis identified on contrast enhanced computed tomography (CT) scan of the abdomen in the course of treatment for acute appendicitis.
Iatrogenic diaphragmatic entry following thoracic surgery is rare with only two cases reported till date. This case reports on a 46-year-old male with persistent pleural sepsis due to right empyema thoracis despite best medical ef- forts. Following a right thoracotomy and decortication, the right diaphragm was inadvertently incised due to dense adhesions between the diaphragm and thickened cortex. To our knowledge, this is the third case reported of iatro- genic diaphragmatic entry following thoracic surgery for empyema thoracis. The pearls from this case report is that any evidence of empyema thoracis involving the lower lobe on imaging should warn the surgeons to be aware of inadvertent entry into the peritoneal cavity, as the diaphragm can be adherent to the cortex trapping the lower lobe.
Two EU directives which are RoHS and WEEE have restricted the usage of certain hazardous substances in
electrical and electronic equipment. This has led to the introduction of green compound which is halogen free. The
non-halogenated molding compound with different recipes was developed by compound manufacturers without
compromising the reliability performance of electronic packages. The focus, often, has been on product reliability
performance while qualifying new materials which overlook relevant safety and health concerns that might incur
during the production stage. This paper is intended to study the forming of crystalline deposits which are found at
the exhaust inlet of the Post Mold Cure Oven (PMC) arising from the usage of this green compound. The writers will
investigate the underlying reasons and the impact on the work environment and the potential risk on health. From the
initial evaluation result, the writers have indentified Compound A as the cause of this deposition. Data analyzed from
the Thermo-Gravimetric Analysis (TGA) revealed higher weight loss which was 0.26% for compound A compared to
other green compounds which are also used. Differential Scanning Calorimetric (DSC) test shows melting temperature
of crystallized particle at 139°C while cold crystallization temperature at 80°C. The temperature in the interior of the
oven is 180°C while the temperature at the exhaust inlet which is exposed to room temperature, and thus, providing
the opportunity for this deposition. Further study carried out using Fourier Transform Infrared (FTIR) spectroscopy
on one of the ingredient of the green compound (material C) observed a 95% spectrum matching compared to the
crystallized particle. Material C is a catalyst added to the mold compound for epoxy-phenolic reaction. It is also
considered to have the capability to enhance flame retardation. This paper will discuss in detail the characteristics of
Compound A green compound and its impact on human and environment.