Development of a Biosensor to Detect Venom of Malayan Krait (Bungarus candidus).

Malayan krait (Bungarus candidus) envenoming is a cause of significant morbidity and mortality in many Southeast Asian countries. If intubation and specific antivenom administration are delayed, the most significant life-threatening outcome may be the inhibition of neuromuscular transmission and subsequent respiratory failure. It is recommended that krait-envenomed victims without indications of neurotoxicity, e.g., skeletal muscle weakness or ptosis, immediately receive 10 vials of antivenom. However, the administration of excess antivenom may lead to hypersensitivity or serum sickness. Therefore, monitoring venom concentrations in patients could be used as an indicator for snake antivenom treatment. In this study, we aimed to develop a screen-printed gold electrode (SPGE) biosensor to detect B. candidus venom in experimentally envenomed rats. The gold electrodes were coated with monovalent Malayan krait IgG antivenom and used as venom detection biosensors. Electrochemical impedance spectrometry (EIS) and square wave voltammetry (SWV) measurements were performed to detect the electrical characterization between B. candidus venom and monovalent IgG antivenom in the biosensor. The EIS measurements showed increases in charge transfer resistance (Rct) following IgG immobilization and incubation with B. candidus venom solution (0.1-0.4 mg/mL); thus, the antibody was immobilized on the electrode surface and venom was successfully detected. The lowest current signal was detected by SWV measurement in rat plasma collected 30 min following B. candidus experimental envenoming, indicating the highest level of venom concentration in blood circulation (4.3 ± 0.7 µg/mL). The present study demonstrates the ability of the SPGE biosensor to detect B. candidus venom in plasma from experimentally envenomed rats. The technology obtained in this work may be developed as a detection tool for use along with the standard treatment of Malayan krait envenoming.

Short term effect of tetrahydrocurcumin on adipose angiogenesis in very high-fat diet-induced obesity mouse model.

Tetrahydrocurcumin (THC) has been shown to possess anti-angiogenic activities. This study aims to investigate the effects of THC on adipose angiogenesis and expression of angiogenic factors that occurs in 60% high-fat diet-induced obese mice. Male ICR mice were randomly divided into 3 groups: mice fed with a low-fat diet (LFD group); mice fed with very high fat diet (VHFD group), and mice fed with VHFD supplemented with THC (300 mg/kg/day orally) (VHFD+THC treated group) for 6 weeks. Body weight (BW), food intake, fasting blood sugar (FBS), lipid profiles and visceral fats weight (VF) were measured. The microvascular density (MVD), TNF-α, VEGF, MMP-2, and MMP-9 expressions were evaluated. The VHFD group had significantly increased total cholesterol, triglyceride, food intake, BW, VF, VF/BW ratio, adipocyte size and the number of crown-liked structures as compared to LFD group. THC supplementation markedly reduced these parameters and adipocyte hypertrophy and inflammation in white adipose tissues. MVD, TNF-α, VEGF, MMP-2, and MMP-9 were over-expressed in the VHFD group. However, THC supplementation decreased MVD and reduced expression of TNF-α, VEGF, MMP-2, and MMP-9. In conclusion, THC suppressed angiogenesis in adipose tissue by the downregulation of TNF-α, VEGF, MMP-2, and MMP-9. With its effects on lipid metabolism as well as on food consumption, THC could contribute to lower visceral fat and body weight. Overall, our study demonstrated the potential benefit of THC in mitigating obesity and associated metabolic disorders along with elucidated the suppression of adipose angiogenesis as one of its underlying mechanisms.

Experience of online physiology laboratory teaching for undergraduate students during the COVID-19 pandemic in Thailand.

The COVID-19 pandemic has disrupted traditional face-to-face human physiology teaching for students at the Faculty of Medicine, Thammasat University, Thailand since February 2020. An online curriculum for both lectures and laboratory sessions was developed to continue the education. This work compared the effectiveness of online physiology labs to the traditional onsite counterparts for 120 dental and pharmacy sophomore students during the 2020 academic year. The method used was a Microsoft Teams synchronous online laboratory experience consisting of eight topics. Faculty lab facilitators created protocols, video scripts, online assignments, and instruction notes. Group lab instructors prepared and delivered the content for recording and led the student discussion. Data recording and live discussion were synchronized and executed. The response rates for the control (2019) and study (2020) groups were 36.89 and 60.83%, respectively. The control group reported higher satisfaction about general laboratory experience, compared to the online study group. The online group rated the laboratory online experience with equal satisfaction to that of an onsite lab experience. The onsite control group reported 55.26% satisfaction with the equipment instrument, while only 32.88% online group voiced their approval of this measure. It was understandable because the excitement in physiology work relies heavily on the experience of the work (P < 0.027). With the same difficulty index for both academic year examination papers, the nonsignificant difference in academic performance of the control and study groups (59.50 ± 13.50 and 62.40 ± 11.43, respectively) showed the effectiveness of our online synchronous physiology lab teaching. In conclusion, the online physiology learning experience was appreciated when a good design was achieved.NEW & NOTEWORTHY The COVID-19 pandemic has forced physiology educators to use online teaching. At the time of this work, there was no research investigating the effectiveness of online and face-to-face physiology lab teaching in undergraduate students. A synchronized online lab teaching of a virtual lab classroom on the Microsoft Teams platform was successfully implemented. Our data showed that online physiology lab teaching could make the students understand physiology concepts and have the same effectiveness as the onsite lab experience.

Evaluation of the geographical utility of Eastern Russell's viper (Daboia siamensis) antivenom from Thailand and an assessment of its protective effects against venom-induced nephrotoxicity.

BACKGROUND: Daboia siamensis (Eastern Russell's viper) is a medically important snake species found widely distributed across Southeast Asia. Envenomings by this species can result in systemic coagulopathy, local tissue injury and/or renal failure. While administration of specific antivenom is an effective treatment for Russell's viper envenomings, the availability of, and access to, geographically-appropriate antivenom remains problematic in many rural areas. In this study, we determined the binding and neutralizing capability of antivenoms manufactured by the Thai Red Cross in Thailand against D. siamensis venoms from four geographical locales: Myanmar, Taiwan, China and Thailand. METHODOLOGY/PRINCIPLE FINDINGS: The D. siamensis monovalent antivenom displayed extensive recognition and binding to proteins found in D. siamensis venom, irrespective of the geographical origin of those venoms. Similar immunological characteristics were observed with the Hemato Polyvalent antivenom, which also uses D. siamensis venom as an immunogen, but binding levels were dramatically reduced when using comparator monovalent antivenoms manufactured against different snake species. A similar pattern was observed when investigating neutralization of coagulopathy, with the procoagulant action of all four geographical venom variants neutralized by both the D. siamensis monovalent and the Hemato Polyvalent antivenoms, while the comparator monovalent antivenoms were ineffective. These in vitro findings translated into therapeutic efficacy in vivo, as the D. siamensis monovalent antivenom was found to effectively protect against the lethal effects of all four geographical venom variants preclinically. Assessments of in vivo nephrotoxicity revealed that D. siamensis venom (700 µg/kg) significantly increased plasma creatinine and blood urea nitrogen levels in anaesthetised rats. The intravenous administration of D. siamensis monovalent antivenom at three times higher than the recommended scaled therapeutic dose, prior to and 1 h after the injection of venom, resulted in reduced levels of markers of nephrotoxicity and prevented renal morphological changes, although lower doses had no therapeutic effect. CONCLUSIONS/SIGNIFICANCE: This study highlights the potential broad geographical utility of the Thai D. siamensis monovalent antivenom for treating envenomings by the Eastern Russell's viper. However, only the early delivery of high antivenom doses appears to be capable of preventing venom-induced nephrotoxicity.