Background: A thymectomy is considered effective for patients with myasthenia gravis (MG). Although a few studies have described the role of a thymectomy in the treatment of MG in Asians countries, there are no published data on the application of this surgical approach for MG in Malaysia. We aimed to describe the clinical outcomes of MG patients who underwent a thymectomy and the factors affecting these outcomes. Methods: This was a retrospective study involving 16 patients with MG who underwent a thymectomy at the Hospital Universiti Sains Malaysia (HUSM) from January 2002 until December 2012, with a follow-up period ranging from 3–120 months. Results: The study consisted of 16 patients aged 22–78 years, 10 of whom were males. The overall remission/improvement rate was 87.5%, and the rate of clinical outcomes classified as unchanged/ worsened was 12.5%. Thymomamatous or non-thymomamatous MG, histology features, Osserman stage and the duration of follow-up were not significant prognostic factors. Post-operative mortality was 6.2% (1 of 16 patients died of septic shock). Conclusion: A thymectomy seems to be an effective treatment for MG, with low surgical morbidity. Patients with a lower Osserman stage and those with/without thymomas had favourable outcomes.

Aims: The search for new antibiotics is an ongoing effort and has expanded to pristine niche areas in the Antarctic in recent years due to the emergence of multi-drug resistant pathogens that outpaced the discovery of new antibiotics. We have recently isolated two new actinomycetes strains, INACH3013a and INACH3013b, which displayed antimicrobial properties from soil samples collected from Ardley Island, Antarctica. Hence, an investigation was carried out to identify them and to characterise the antimicrobial compounds produced. Methodology and results: Strains, INACH3013a and INACH3013b were identified based on their 16S rDNA sequence alignment to those in the GenBank. The results showed that strain INACH3013a was closest to Streptomyces spp. while strain INACH3013b was closest to Streptomyces corallincola and Streptomyces bullii. The extracellular compounds they produced were extracted using various solvents and the extracted compounds were tested against the test pathogens. The dichloromethane extracts from strains, INACH3013a and INACH3013b inhibited mainly Gram-positive pathogens that include Listeria monocytogenes, Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus equorum, Bacillus cereus K3 and Enterococcus faecalis while extracts from strain INACH3013b also inhibited a Gram-negative pathogen, Klebsiella pneumonia 14x. Predominantly non-polar constituents seem responsible for antibacterial effects, with dichloromethane extracts proving most efficacious, followed by chloroform and ethyl acetate. Conclusion, significance and impact of study The research highlights the potential of Streptomyces spp. INACH3013a and INACH3013b as a source of potential novel antibiotics. This research explores Antarctic Streptomyces strains' antimicrobial capabilities, enabling the potential for the discovery of novel antibiotics and revealing how these compounds may have helped them to compete and survive in nutrient-deficient Antarctic niches.

Objective: To investigate the inhibitory effect on Burkholderia pseudomallei (B. pseudomallei) strain HNBP001 of a bacillomycin D-like cyclic lipopeptide compound named bacillomycin DC isolated from Bacillus amyloliquefaciens HAB-2. Methods: The antibacterial effect of bacillomycin DC on B. pseudomallei was determined using the disk diffusion method. The minimum inhibitory concentrations were evaluated by microdilution assay. In addition, transmission electron microscopy was performed and quantitative real-time polymerase chain reaction assay was carried out to determine the expression of MexB, OprD2, and qnrS genes. Results: Bacillomycin DC produced an inhibition zone against B. pseudomallei with minimum inhibitory concentration values of 12.5 μg/mL 24 h after treatment and 50 μg/mL at 48 and 72 h. Transmission electron microscopy showed that bacillomycin DC resulted in roughening cell surface and cell membrane damage. Quantitative real-time polymerase chain reaction analysis showed low expression of MexB, OprD2 and qnrS genes. Conclusions: Bacillomycin DC inhibits the growth of B. pseudomallei and can be a new candidate for antimicrobial agents of B. pseudomallei. Rajaofera Mamy 1 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Kang Xun 2 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Jin Peng-Fei 3 Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, Hainan Chen Xin 4 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Li Chen-Chu 5 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Yin Li 6 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Liu Lin 7 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Sun Qing-Hui 8 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Zhang Nan 9 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Chen Chui-Zhe 10 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan He Na 11 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Xia Qian-Feng 12 Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan Miao Wei-Guo 13 Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, Hainan Kung CT, Lee CH, Li CJ, Lu HI, Ko SF, Liu JW. 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