Gene expression patterns of Glaciozyma antarctica PI12 in response to cold, and freeze stress

Psychrophilic yeast, Glaciozyma antarctica PI12 was isolated from the sea ice in the Southern Ocean. Several recent studies have revealed some of the strategies employed by G. antarctica PI12 to grow and survive at low temperatures, but those information are still limited. Hence this project was carried out to sequence the whole transcriptome to generate additional information on the cold-adaptation strategies of G. antarctica PI12. The yeast grown optimally in Saccharomyces cerevisiae minimal medium at 12 °C was subsequently exposed to cold-shock at 0 °C and freeze-shock at −12 °C for 6 h and 24 h. RNA from those cells were extracted, sequenced, and analyzed. Interestingly, the results showed that G. antarctica PI12 remained metabolically active at −12 °C. Two hundred and five genes were differentially expressed in the cells. Among them, 107 genes were upregulated while 98 genes were downregulated. In the first 6 h after the cells were exposed to cold- and freeze-shocks, CCR4-NOT (carbon catabolite repressed 4 - negative on TATA-less) core subunit cdc36, DNA repair protein Rad8, Elongation factor 1-gamma, 26s proteosome subunit 45, and Homocitrate synthase genes were commonly upregulated to perform several immediate and important tasks to ensure the cells survived. Apart from that, there were also genes upregulated and downregulated uniquely at 6 h and 24 h to facilitate the cells to adjust to the new temperatures. After overcoming the stress of the cold- and freeze-shocks for 24 h, the cells acclimatized to those temperatures and became metabolically active again, and the cell cycles related genes were up-regulated

Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide

Modeling of industrial sector in Singapore

With the world’s conventional energy sources dwindling over the years and the mounting threat of environmental consequences caused by the ever increasing use of these energy sources, it is in the interest of every country to plan her energy needs for the future. Singapore, too, is vulnerable to this energy threat and consequences. Being a country that has enjoyed fast growth over the past few decades, Singapore inevitably has a keen interest to plan for her energy needs to sustain her growth. At the forefront driving Singapore’s economic growth is her industrial sector, which has been one of the main pillars of the country. The ability to model the industrial sector of Singapore would provide great potential for policy planning. In this project, a model using the Markal framework is developed on Singapore’s industrial sector, over a span of thirty years, from year 2000 to 2030. Markal allows for the optimization of the model created, by obtaining the lowest energy system cost. As specific data regarding industrial technology remains highly guarded in this field, assumptions have been made during the creation of the model. From the results generated by Markal, it is seen that second generation technology are the preferred choice due to the improvement in efficiency. In areas where competing base technology are present, such as lightings and HVAC, energy saving light bulbs and second generation split unit are selected respectively as the most cost effective technology. In conclusion, although the model created does not fully reflect the entire Singapore energy situation, it possesses the ability of portraying Singapore’s industrial sector into the near future. By acquiring more accurate information, the accuracy of this model would be greatly enhanced.Bachelor of Engineering (Mechanical Engineering

Characterisation Of an Antarctic Yeast, Glaciozyma Antarctica PI12

Glaciozyma antarctica PI12 is a psychrophilic yeast isolated from Antarctica. It has an optimal growth in yeast peptone dextrose (YPD) and yeast mould (YM) broth media but not in potato dextrose (PD) broth medium. Early phase G. antarctica PI12 cells had elongated-shape and became oval-shaped as they aged. G. antarctica PI12 exhibited bipolar budding and formed a chain of cells during the lag and early exponential phases. The number of chains decreased as the yeast aged. It appeared mainly as a single cell at the stationary phase, and a small number of them still produced buds. Some cells at the stationary phase entered the quiescence state (G0) as a long-term survival strategy. The G. antarctica PI12 cell size decreased when they entered the stationary phase. G. antarctica PI12 was found to produce hydrolytic enzymes, chitinase, cellulase, mannanase, and xylanase. A higher glucose concentration of 2% in the PD agar medium inhibited the activities of chitinase but not the cellulase, mananase and xylanase

Concurrent amoebic and histoplasma colitis: A rare cause of massive lower gastrointestinal bleeding

Infective colitis can be a cause of massive lower gastrointestinal bleeding requiring acute surgical intervention. Causative organisms include entamoeba and histoplasma species. However, concurrent colonic infection with both these organisms is very rare, and the in vivo consequences are not known. A 58-year-old male presented initially to the physicians with pyrexia of unknown origin and bloody diarrhea. Amoebic colitis was diagnosed based on biopsies, and he was treated with metronidazole. Five days later, the patient developed massive lower gastrointestinal bleeding with hemorrhagic shock. Emergency total colectomy with end-ileostomy was performed. However, he deteriorated and died on the second postoperative day. Histopathological examination revealed multiple deep ulcers at the hepatic flexure where fungal bodies of mycelial and yeast forms were noted. Isolated lymph nodes showed abscess formation with fungal bodies. Infective fungal colitis with Histoplasma capsilatum was diagnosed. In vitro, amoebic parasites can increase virulence and pathogenicity of histoplasma which may account for the fulminant presentation in this patient. Although rare, this unusual dual infection should be considered in the differential diagnosis of infective colitis, as appropriate antimicrobial treatment may prevent progression to massive lower gastrointestinal bleeding, obviating the need for urgent surgical intervention

Deciphering the mechanism of HNE-induced apoptosis in cultured murine cortical neurons: Transcriptional responses and cellular pathways

Studies have shown that the lipid peroxidation by-product, 4-hydroxynonenal (HNE), is involved in many pathological events in several neurodegenerative diseases. A number of signaling pathways mediating HNE-induced cell death in the brain have been proposed. However, the exact mechanism remains unknown. In the present study, we have examined the effects of HNE on cultured primary cortical neurons and found that HNE treatment leads to cell death via apoptosis. Both the caspase and calpain proteolytic systems were activated. There were also increased levels of phospho-p53 and cell cycle-related proteins. Gene transcription was further studied using microarray analysis. Results showed that majority of the genes associated with cell cycle regulation, response to stress, and signal transduction were differentially expressed. The various categories of differentially-expressed genes suggested that there are other parallel pathways regulating HNE-induced neuronal apoptosis. Collectively, these might help to elucidate similar molecular mechanisms involved during cell death in neurodegenerative diseases

The Spectrum of Anti-GAD Antibody Associated Neuro-Ophthalmological and Neurological Conditions

Neuro-ophthalmologists are aware of the association between anti-GAD antibodies and nystagmus, in particular downbeat nystagmus. It occurs in the context of diffuse cerebellar degeneration but may be an isolated phenomenon. In addition, anti-GAD antibodies are associated with a number of neurological syndromes and systemic autoimmunity, some of which co-exist and have important diagnostic and therapeutic implications. Neuro-ophthalmologists should therefore be familiar with this spectrum