METHODS: This study examined the immunological binding and neutralization capacity of PCAV against the two cobra venoms using WHO-recommended protocols.
RESULTS: In mice, both venoms were highly neurotoxic and lethal with a median lethal dose of 0.18 and 0.20 µg/g, respectively. PCAV exhibited strong and comparable immunoreactivity toward the venoms, indicating conserved venom antigenicity between the two allopatric species. In in vivo assay, PCAV was only moderately effective in neutralizing the toxicity of both venoms. Its potency was even lower against the hetero-specific N. samarensis venom by approximately two-fold compared with its potency against N. philippinensis venom.
CONCLUSION: The results indicated that PCAV could be used to treat N. samarensis envenomation but at a higher dose, which might increase the risk of hypersensitivity and worsen the shortage of antivenom supply in the field. Antivenom manufacturing should be improved by developing a low-dose, high-efficacy product against cobra envenomation.
BIOLOGICAL SIGNIFICANCE: Advents in proteomics and bioinformatics have vigorously propelled the scientific discoveries of toxins from various lineages of venomous snakes. The Malayan pit viper, Calloselasma rhodostoma, is a medically important species in Southeast Asia as its bite can cause envenomation, while the venom is also a source of bioactive compounds for drug discovery. Detailed profiling of the venom, however, is inadequate possibly due to the complex nature of the venom and technical limitation in separating the constituents into details. Integrating a multi-step fractionation method, this study successfully revealed a comprehensive and quantitative profile of the composition of the venom of this medically important venomous snake. The relative abundance of the various venom proteins is determined in a global profile, providing useful information for understanding the pathogenic roles of the different toxins in C. rhodostoma envenomation. Notably, the principal hemotoxins were identified in great details, including the variety of toxin subunits and isoforms. The findings indicate that these toxins are the principal targets for effective antivenom neutralization, and should be addressed in the production of a pan-regional polyspecific antivenom. In addition, minor toxin components not reported previously in the venom were also detected in this study, enriching the current toxin database for the venomous snakes.
MATERIALS AND METHODS: All information on P. acidus was collected from various electronic database (ACS, PubMed, Scopus, Web of Science, SciFinder, Science Direct, Google Scholar, Springer, Wiley, Taylor and Mendeley) and also from those published materials (Ph.D. and M.Sc. dissertations and books) by using a combination of various meaningful keywords.
RESULTS: Phytochemical analyses on barks, leaves, roots and fruits of P. acidus identified triterpene, diterpene, sesquiterpene, and glycosides as predominant classes of bioactive substances found in this plant. P. acidus was reported with various pharmacological activities such as in vivo hepatoprotective and hypoglycemic, in vitro anti-oxidant, α-glucosidase inhibitory, anti-inflammatory and antimicrobial activities. However, none of these studies are with clinical research. Some of the studies were performed with only a single set of experiments or with a high dose of extract, and thus the validity of the experimental data may be questionable. In addition, most of the studies described were without identifying the effective components. Some of the assays were even without a positive control for comparison which makes results questionable.
CONCLUSION: Although P. acidus has been proven as a valuable medicinal source from its traditional uses. However, the pharmacological experiments conducted were not sufficient to verify its traditional uses. More investigation is required to confirm the traditional claims such as bioassay-guided isolation of bioactive compounds, detailed pharmacological investigations, clinical studies, and its toxicity investigation. Additionally, an experimental design with sufficient data replication, the use of controls and authenticated research materials, and the selection of a rationale dose or concentration for the analysis are keys to providing reproducible experimental data.
Materials and Methods: Thirteen consecutive patients who underwent pre-operative embolisation of a musculoskeletal tumour followed by surgical intervention at our institution from May 2012 to January 2016 were enrolled into the study. Patient demographics, tumour characteristics, embolisation techniques and type of surgery were recorded. Technical success of embolisation, amount of blood loss during surgery and transfusion requirements were estimated.
Results: There were five female and eight male patients who underwent pre-operative embolisation during the study period. The age ranged between 16 to 68 years, and the median age was 54. Technical success was achieved in all patients. Mean intra-operative blood loss was 1403ml, with a range of 150ml to 6900ml. Eight patients (62%) required intra-operative blood products of packed red blood cells and fresh frozen plasma. No major complications occurred during embolisation.
Conclusion: Pre-operative trans-arterial embolisation is feasible and safe for a variety of large and hypervascular musculoskeletal tumours. Our small series suggests that preoperative embolisation could contribute to the reduction of the intra-operative and post-operative blood product transfusion. It should be considered as a pre-operative adjunct for major tumour resections with a high risk of bleeding. The use of the haemoglobin gap complemented the assessment of perioperative blood loss.
AIM: This study examined the behavioural prevention practices against SARS-CoV-2 infection and the intention to vaccinate among older people when the COVID-19 vaccine is on the verge of becoming available.
METHOD: A cross-sectional, online survey was conducted between 14th July and 8th October 2020 among the older people in Malaysia. A questionnaire was designed to assess the practice towards measures preventing SARS-CoV-2 infection, and COVID-19 vaccination attitudes and intention. Socio-demographic characteristics, constructs of a health belief model (HBM), the 6-item state version of the State-Trait Anxiety Inventory (STAI-6) were correlates of the main outcomes.
FINDINGS: The mean score of total preventive measures scores was 13.4 ± 1.7 out of a maximum score of 15, indicating very good prevention practices. By demographics, females, having a tertiary education exhibited higher prevention practices in the univariable analyses. Components of the HBM and being female remain significant correlates of higher prevention practices in multivariable logistic regression analysis (MLRA). A total of 657 (87.1%) participants responded and intend to receive the COVID-19 vaccination. Provider recommendations may improve vaccination uptake (91.6%). MLRA revealed that having a positive vaccination attitude was 16 times more likely to accept the COVID-19 vaccination (OR = 16.10; 95% CI 8.97-28.91). Hearing of someone they know who has COVID-19 serves as a cue to action and significantly influences vaccination (OR = 4.25; 95% CI 1.80-10.03). Participants below 70 years old expressed higher vaccination intention (OR = 2.07; 95% CI 1.19-3.58).
CONCLUSION: The results provide the first evidence for public authorities to target older people vulnerable to compliance with recommended preventive measures against SARS-CoV-2 infections.
MATERIALS AND METHODS: We did a retrospective medical record review of all patients with SS from July 2014 to July 2018 at Hospital Queen Elizabeth and Hospital Pulau Pinang, both tertiary hospitals in Malaysia.
RESULTS: Twenty-nine patients were included. Approximately half of the patients (15) were females with a mean age of onset of 50.93 (± 11.52) years. The most common subtype was classic (62.0%) followed by malignancy-associated (31.0%) and drug-induced (6.9%). Among the patients with the classic subtype, infective-related causes (50.0%) were the most common. Among the patients with malignancy, eight had haematological malignancy and one had a solid tumour. Two-third of the malignancies were diagnosed within a year after the diagnosis of SS. Eight of our patients in Sabah had mycobacterial infections with three having concomitant haematological malignancies. Patients with malignancy-associated SS had lower mean haemoglobin (p=0.018) and mean platelet count (p=0.031). Itch was associated with the presence of pustules (p=0.038). Histopathological examination of all skin lesions showed dermal neutrophilic infiltrates and 25 (86.2%) of them had papillary dermal oedema. The study was limited by its retrospective design. The sample size was small likely due to the uncommon occurrence of this condition.
CONCLUSION: SS is an uncommon dermatosis with distinctive clinical and histopathological features. Screening for underlying malignancy is essential especially for those who present with anaemia, thrombocytopenia, and pathergy phenomenon. Mycobacterial infection should be considered in this region due to high tuberculosis burden.