Proposal of a new slit-lamp shield for ophthalmic examination and assessment of its effectiveness using computational simulations / Avaliação da eficácia e proposta de um novo protetor de lâmpada de fenda durante exame oftálmico por meio de simulações computacionais

ABSTRACT Purpose: This study aimed to use computational models for simulating the movement of respiratory droplets when assessing the efficacy of standard slit-lamp shield versus a new shield designed for increased clinician comfort as well as adequate protection. Methods: Simulations were performed using the commercial software Star-CCM+. Respiratory droplets were assumed to be 100% water in volume fraction with particle diameter distribution represented by a geometric mean of 74.4 (±1.5 standard deviation) μm over a 4-min duration. The total mass of respiratory droplets expelled from patients' mouths and droplet accumulation on the manikin were measured under the following three conditions: with no slit-lamp shield, using the standard slit-lamp shield, and using our new proposed shield. Results: The total accumulated water droplet mass (kilogram) and percentage of expelled mass accumulated on the shield under the three aforementioned conditions were as follows: 5.84e-10 kg (28% of the total weight of particle emitted that settled on the manikin), 9.14e-13 kg (0.045%), and 3.19e-13 (0.015%), respectively. The standard shield could shield off 99.83% of the particles that would otherwise be deposited on the manikin, which is comparable to 99.95% for the proposed design. Conclusion: Slit-lamp shields are effective infection control tools against respiratory droplets. The proposed shield showed comparable effectiveness compared with conventional slit-lamp shields, but with potentially enhanced ergonomics for ophthalmologists during slit-lamp examinations.

RESUMO Introdução: Os oftalmologistas têm alto risco de contrair a doença do Coronavírus-19 devido à proximidade com os pacientes durante os exames com lâmpada de fenda. Usamos um modelo de computação para avaliar a eficácia das proteções para lâmpadas de fenda e propusemos uma nova proteção ergonomicamente projetada. Métodos: As simulações foram realizadas no software comercial Star-CCM +. Os aerossóis de gotículas foram considerados 100% de água em fração de volume com distribuição de diâmetro de partícula representada por uma média geométrica de 74,4 ± 1,5 (desvio padrão) μm ao longo de uma duração de quatro minutos. A massa total de gotículas de água acumulada no manequim e a massa expelida pela boca do paciente foram medidas em três condições diferentes: 1) Sem protetor de lâmpada de fenda, 2) com protetor padrão, 3) Com o novo protetor proposto. Resultados: A massa total acumulada das gotas de água (kg) e a porcentagem da massa expelida acumulada no escudo para cada uma das respectivas condições foram; 1) 5,84e-10 kg (28% do peso total da partícula emitida que assentou no manequim), 2) 9,14e-13 kg (0,045%), 3,19e-13 (0,015%). O escudo padrão foi capaz de proteger 99,83% das partículas que, de outra forma, teriam se depositado no manequim, o que é semelhante a 99,95% para o projeto proposto. Conclusão: Protetores com lâmpada de fenda são ferramentas eficazes de controle de infecção contra gotículas respiratórias. O protetor proposto mostrou eficácia comparável em comparação com os protetores de lâmpada de fenda convencionais, mas potencialmente oferece uma melhor ergonomia para oftalmologistas durante o exame de lâmpada de fenda.

Lipid droplets in Zika neuroinfection: Potential targets for intervention?

Lipid droplets (LD) are evolutionarily conserved lipid-enriched organelles with a diverse array of cell- and stimulus-regulated proteins. Accumulating evidence demonstrates that intracellular pathogens exploit LD as energy sources, replication sites, and part of the mechanisms of immune evasion. Nevertheless, LD can also favor the host as part of the immune and inflammatory response to pathogens. The functions of LD in the central nervous system have gained great interest due to their presence in various cell types in the brain and for their suggested involvement in neurodevelopment and neurodegenerative diseases. Only recently have the roles of LD in neuroinfections begun to be explored. Recent findings reveal that lipid remodelling and increased LD biogenesis play important roles for Zika virus (ZIKV) replication and pathogenesis in neural cells. Moreover, blocking LD formation by targeting DGAT-1 in vivo inhibited virus replication and inflammation in the brain. Therefore, targeting lipid metabolism and LD biogenesis may represent potential strategies for anti-ZIKV treatment development. Here, we review the progress in understanding LD functions in the central nervous system in the context of the host response to Zika infection.

Role of organelle interaction in the development and progression of nonalcoholic fatty liver disease / 临床肝胆病杂志

In addition to its own specific functions, an organelle can also interact with other organelles to complete important physiological functions. The disorders of organelle interactions are closely associated the development and progression of various diseases. In recent years, the role of organelle interactions has attracted more attention in the progression of nonalcoholic fatty liver disease, especially the interactions between mitochondria, lipid droplets, and other organelles.

Reinforcement of sterols production through directed storage and transportation in yeast: a review / 生物工程学报

Sterols, a class of cyclopentane poly-hydrophenanthrene derivatives, are the predominant membrane constituent of eukaryotes. These substances have a variety of biological activities and have been widely used in food and pharmaceutical industries. The presence of endogenous ergosterol biosynthetic pathway in Saccharomyces cerevisiae cells make it an ideal chassis for the de novo synthesis of sterol and its derivatives. Most recently, the rational modification of organelles provides a novel strategy for the directed transportation and storage of target products and the ultimate enhanced product synthesis. This review summarizes the phenotypic responses of S. cerevisiae cells upon different physiological stimulations and the underlying molecular mechanisms. Reinforcement of sterol production through directed storage, transportation, and excretion of sterols offers a novel strategy for breaking the limitation of de novo biosynthesis of sterols in yeast.

CRISPR/Cas9 knockout plin1 enhances lipolysis in 3T3-L1 adipocytes / 生物工程学报

We used CRISPR/Cas9 to delete plin1 of 3T3-L1 preadipocyte, to observe its effect on lipolysis in adipocytes and to explore regulatory pathways. We cultured 3T3-L1 preadipocytes, and the plin1 knockout vectors were transfected by electroporation. Puromycin culture was used to screen successfully transfected adipocytes, and survival rates were observed after transfection. The optimized "cocktail" method was used to differentiate 3T3-L1 preadipocytes. The glycerol and triglyceride contents were determined by enzymatic methods. The changes in lipid droplet form and size were observed by Oil red O staining. The protein expression of PLIN1, PPARγ, Fsp27, and lipases was measured by Western blotting. RT-PCR was used to measure the expression of PLIN1 and lipases mRNA. After the adipocytes in the control group were induced to differentiate, the quantity of tiny lipid droplets was decreased, and the quantity of unilocular lipid droplets was increased and arranged in a circle around the nucleus. Compared with the control group, the volume of unilocular lipid droplets decreased, and the quantity of tiny lipid droplets increased after induction of adipocytes in the knockout group. The expression of PLIN1 mRNA and protein in the adipocytes was significantly inhibited (P<0.05); glycerol levels increased significantly (0.098 4±0.007 6), TG levels decreased significantly (0.031 0±0.005 3); mRNA and protein expression of HSL and ATGL increased (P<0.05); PPARγ and Fsp27 expression unchanged in adipocytes. The above results indicate that the knockout of plin1 enhances the lipolysis of 3T3-L1 adipocytes by exposing lipids in lipid droplets and up-regulating lipases effects.

Progress in the study of the association between the lipid droplets and hepatitis C virus life cycle / 药学学报

Lipid droplets (LDs) are ubiquitous dynamic organelles that store and supply lipids in all eukaryotic and some prokaryotic cells for energy metabolism, membrane synthesis and production of essential lipid-derived molecules. There is increasing evidence that hepatitis C virus (HCV) has co-evolved due to its lack of lipid biosynthetic pathways to utilize host lipid metabolic pathways to establish a suitable environment for virus proliferation and obtain the necessary components, eventually promote the assembly and transportation of virus. In this review, we outline the relationship between HCV life cycle and lipid droplet biosynthesis and metabolism, with the aim to discover potential antiviral targets for development of new therapeutic interventions.

Omic studies reveal the pathogenic lipid droplet proteins in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is an epidemic metabolic condition driven by an underlying lipid homeostasis disorder. The lipid droplet (LD), the main organelle involved in neutral lipid storage and hydrolysis, is a potential target for NAFLD therapeutic treatment. In this review, we summarize recent progress elucidating the connections between LD-associated proteins and NAFLD found by genome-wide association studies (GWAS), genomic and proteomic studies. Finally, we discuss a possible mechanism by which the protein 17β-hydroxysteroid dehydrogenase 13 (17β-HSD13) may promote the development of NAFLD.

The Distribution of the Lipid Droplets within Hensen Cells in the Guinea -pig Cochlea / 听力学及言语疾病杂志

Objective To study the distribution and properly of the transparent globules within Hensen cells (HC) of guinea -pig Corti organ .Methods The cochlear epithelial cells were isolated from 10 guinea pigs .The cells of cochlea were marked by Bodipy493/503 ,sudan III ,oil red O ,and osmium tetroxide .Results The transpar‐ent globules within the HCs of the guinea -pigs were green staining by Bodipy493/503 ,jacinth staining by Sudan III ,ruby red by oil red O .And they were black globules stripe as post -fixed in 1% osmium tetroxide .Conclusion The results indicate that the transparent globules within guinea -pigs HCs'lipid droplets by four methods .

Inhibitory Effect of Oleanolic Acid on Lipid Accumulation in Cytoplasm of 3T3-L1 Adipocyte / 世界科学技术-中医药现代化

A collection of 57 natural compounds derived from Chinese herbal medicines were evaluated for their an-ti-adipogenic effects. The lipid droplets in differentiated 3T3-L1 adipocytes treated with tested substrate were de-tected by an image-based assay. The results demonstrated that oleanolic acid (OA) inhibited lipid droplets accumula-tion in 3T3-L1 adipocytes in a dose-dependent manner with the IC50 value of 14.5 μmol·L-1. In addition, ToxInsight assay showed that OA was free of liver injury for HepG2 cells within 60 μmol·L-1. It was concluded that OA, which had an obvious anti-adipogenic effect, can be a candidate for hyperlipidemia therapy.

Effects of SREBP-1 targeted RNAi on lipid droplet formation in HKC cells under stimulation of high glucose / 中国药理学通报

Aim To construct eukaryotic expression vector of shRNA(small hairpin RNA)for human SREBP-1(sterol regulation element binding protein-1)gene and explore its effects on lipid droplet formation in human renal proximal tubular epithelial cell line(HKC)under the stimulation of high glucose.Methods Two eukaryotic expression vectors of shRNA were constructed for human SREBP-1 gene.The HKC cells were transfected with negative control plasmid(pGenesil-1-HK)and two recombinant vectors(pGenesil-1-SREBP1-1 and pGenesil-1-SREBP1-2)and then were cultured under the stimulation of high glucose for about 48 h.The expression of SREBP-1 mRNA and FAS mRNA was detected by RT-PCR and SREBP-1 protein expression was investigated by Western blot.Lipid droplets were detected by Oil Red O staining.Results DNA sequencing showed that the target segments were successfully cloned into pGenesil-1 vector respectively.RT-PCR indicated that two recombinant vectors could inhibit the expression of SREBP-1 mRNA and FAS mRNA in HKC cells under the stimulation of high glucose.Similarly,SREBP-1 protein was also inhibited by the transfection with recombinant vectors.Oil Red O staining found that silencing of SREBP-1 gene resulted in lipid droplets decrease.Conclusions The eukaryotic expression vector of shRNA for human SREBP-1 gene was successfully constructed,and the expression of SREBP-1 was inhibited effectively by the expressed siRNA in HKC cells that resulted in lipid droplets decrease through FAS mRNA transcription inhibition.