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EMBO Reports Mar 2018Interfering with mitosis for cancer treatment is an old concept that has proven highly successful in the clinics. Microtubule poisons are used to treat patients with... (Review)
Review
Interfering with mitosis for cancer treatment is an old concept that has proven highly successful in the clinics. Microtubule poisons are used to treat patients with different types of blood or solid cancer since more than 20 years, but how these drugs achieve clinical response is still unclear. Arresting cells in mitosis can promote their demise, at least in a petri dish. Yet, at the molecular level, this type of cell death is poorly defined and cancer cells often find ways to escape. The signaling pathways activated can lead to mitotic slippage, cell death, or senescence. Therefore, any attempt to unravel the mechanistic action of microtubule poisons will have to investigate aspects of cell cycle control, cell death initiation in mitosis and after slippage, at single-cell resolution. Here, we discuss possible mechanisms and signaling pathways controlling cell death in mitosis or after escape from mitotic arrest, as well as secondary consequences of mitotic errors, particularly sterile inflammation, and finally address the question how clinical efficacy of anti-mitotic drugs may come about and could be improved.
Topics: Apoptosis; Cell Cycle Checkpoints; Cell Death; Humans; Microtubules; Mitosis; Neoplasms
PubMed: 29459486
DOI: 10.15252/embr.201745440 -
Scientific Reports Sep 2021Nanoneedle structures on dragonfly and cicada wing surfaces or black silicon nanoneedles demonstrate antibacterial phenomena, namely mechano-bactericidal action. These...
Nanoneedle structures on dragonfly and cicada wing surfaces or black silicon nanoneedles demonstrate antibacterial phenomena, namely mechano-bactericidal action. These air-exposed, mechano-bactericidal surfaces serve to destroy adherent bacteria, but their bactericidal action in the water is no precedent to report. Calcium carbonate easily accumulates on solid surfaces during long-term exposure to hard water. We expect that aragonite nanoneedles, in particular, which grow on TiO during the photocatalytic treatment of calcium-rich groundwater, exhibit mechano-bactericidal action against bacteria in water. Here, we showed that acicular aragonite modified on TiO ceramics prepared from calcium bicarbonate in mineral water by photocatalysis exhibits mechanical bactericidal activity against E. coli in water. Unmodified, calcite-modified and aragonite-modified TiO ceramics were exposed to water containing E. coli (in a petri dish), and their bactericidal action over time was investigated under static and agitated conditions. The surfaces of the materials were observed by scanning electron microscopy, and the live/dead bacterial cells were observed by confocal laser scanning microscopy. As a result, the synergistic bactericidal performance achieved by mechano-bactericidal action and photocatalysis was demonstrated. Aragonite itself has a high biological affinity for the human body different from the other whisker-sharpen nanomaterials, therefore, the mechano-bactericidal action of acicular aragonite in water is expected to inform the development of safe water purification systems for use in developing countries.
PubMed: 34584148
DOI: 10.1038/s41598-021-98797-w -
HardwareX Apr 2022Multispectral imaging is at the forefront of contactless surface analysis. Standard multispectral imaging systems use sophisticated software, cameras and light filtering...
Multispectral imaging is at the forefront of contactless surface analysis. Standard multispectral imaging systems use sophisticated software, cameras and light filtering optics. This paper discloses the building of a customizable and cost-effective multispectral imaging and analysis system. It integrates a web camera, light emitting diodes (LEDs) lighting, a semisphere for even lightening, an open-source Arduino™ development board and a free Python application to automatically obtain and visually analyze multispectral images. The device is hereafter called MEDUSA and its optical performance was tested for repeated Imaging consistency, visible and near infrared band sensitivity and lighting evenness. Four proof of concept tests were run in order to understand the advantageous use of this system, as compared to a simple visual score of diverse samples. Each of three qualitative tests used sets of 12 LED band spectral images to analyze ink changes in a counterfeit bill, surface bruises on Hass avocado fruits and transient changes in petri dish grown bacterial colonies. A fourth test used single band imaging in a set of standard laboratory analyzed plant samples, to quantitatively relate a red band light reflectance to its nitrogen content. These tests indicate that MEDUSA made images may yield qualitative and quantitative spectral information unseen to the naked eye, suggesting potential use in currency counterfeit tests, food quality analyses, microbial phenotyping and agricultural plant chemistry. MEDUSA can be freely reproduced and customized from this research, making it a powerful and affordable analytical tool to analyze a wide range of subtle chemical properties in samples at industrial and science fields.
PubMed: 35509904
DOI: 10.1016/j.ohx.2022.e00282 -
Biophysics Reviews Mar 2022With a kind of magnetism, the human retina draws the eye of neuroscientist and physicist alike. It is attractive as a self-organizing system, which forms as a part of... (Review)
Review
With a kind of magnetism, the human retina draws the eye of neuroscientist and physicist alike. It is attractive as a self-organizing system, which forms as a part of the central nervous system via biochemical and mechanical cues. The retina is also intriguing as an electro-optical device, converting photons into voltages to perform on-the-fly filtering before the signals are sent to our brain. Here, we consider how the advent of stem cell derived analogs of the retina, termed retina organoids, opens up an exploration of the interplay between optics, electrics, and mechanics in a complex neuronal network, all in a Petri dish. This review presents state-of-the-art retina organoid protocols by emphasizing links to the biochemical and mechanical signals of retinogenesis. Electrophysiological recording of active signal processing becomes possible as retina organoids generate light sensitive and synaptically connected photoreceptors. Experimental biophysical tools provide data to steer the development of mathematical models operating at different levels of coarse-graining. In concert, they provide a means to study how mechanical factors guide retina self-assembly. In turn, this understanding informs the engineering of mechanical signals required to tailor the growth of neuronal network morphology. Tackling the complex developmental and computational processes in the retina requires an interdisciplinary endeavor combining experiment and theory, physics, and biology. The reward is enticing: in the next few years, retina organoids could offer a glimpse inside the machinery of simultaneous cellular self-assembly and signal processing, all in an setting.
PubMed: 38505227
DOI: 10.1063/5.0077014 -
PloS One 2022The purpose of this study was to investigate the abundance and distribution of psychrophilic microorganisms associated with spoilage in beef slaughterhouse environments...
The purpose of this study was to investigate the abundance and distribution of psychrophilic microorganisms associated with spoilage in beef slaughterhouse environments after cleaning. The processing lines and equipment used in slaughtering and boning were swabbed, and the microbial count was determined using a TSA and MRS medium and Chromocult® Coliform agar incubated at 15ºC and 37ºC, respectively. As a result, the brisket saw (handle side) and trolley hook were the most heavily contaminated with microorganisms, with each having a microbial adhesion rate of 66.7%. The microbial adhesion rates of the apron and milling cutter (edge side) were 50%, respectively, and those of the foot cutter (edge and handle side), splitting saw (edge side), and knife (handle side) were 33.3%, respectively. Next, four colonies were randomly isolated from the petri dish used for the bacterial count measurement to identify the predominant microbial species of the microorganisms attached to each equipment. As a result of Sanger sequencing analysis, yeasts such as Candida zeylanoides and Rhodotorula sp. and bacteria including Pseudomonas sp. and Rhodococcus sp. were identified from the equipment used in the slaughtering line, and it was assumed that these microorganisms were of environmental origin. In contrast, only Pseudomonas sp. and Candida zeylanoides were isolated from the boning line. Despite the use of cleaning operations, this study identified some equipment was contaminated with microorganisms. Since this equipment frequently comes into direct contact with the carcass, it is critical to thoroughly remove the microorganisms through accurate cleaning to prevent the spread of microbial contamination on the carcasses.
Topics: Abattoirs; Animals; Cattle; Colony Count, Microbial; Food Handling; Food Microbiology; Japan; Meat; Saccharomycetales; Yeasts
PubMed: 35921278
DOI: 10.1371/journal.pone.0268411 -
Frontiers in Microbiology 2019The new era of multidrug resistance of pathogens against frontline antibiotics has compromised the immense therapeutic gains of the 'golden age,' stimulating a... (Review)
Review
The new era of multidrug resistance of pathogens against frontline antibiotics has compromised the immense therapeutic gains of the 'golden age,' stimulating a resurgence in antimicrobial research focused on antimicrobial and immunomodulatory components of botanical, fungal or microbial origin. While much valuable information has been amassed on the potency of crude extracts and, indeed, purified compounds there are too many reports that uncritically extrapolate observed activity to presumed ingestive and/or topical therapeutic value, particularly in the discipline of ethnopharmacology. Thus, natural product researchers would benefit from a basic pharmacokinetic and pharmacodynamic understanding. Furthermore, therapeutic success of complex mixtures or single components derived therefrom is not always proportionate to their MIC values, since immunomodulation can be the dominant mechanism of action. Researchers often fail to acknowledge this, particularly when 'null' activity is observed. In this review we introduce the most up to date theories of oral and topical bioavailability including the metabolic processes affecting xenobiotic biotransformation before and after drugs reach the site of their action in the body. We briefly examine the common methodologies employed in antimicrobial, immunomodulatory and pharmacokinetic research. Importantly, we emphasize the contribution of synergies and/or antagonisms in complex mixtures as they affect absorptive processes in the body and sometimes potentiate activity. Strictly in the context of natural product research, it is important to acknowledge the potential for chemotypic variation within important medicinal plants. Furthermore, polar head space and rotatable bonds give indications of the likelihood of bioavailability of active metabolites. Considering this and other relatively simple chemical insights, we hope to provide the basis for a more rigorous scientific assessment, enabling researchers to predict the likelihood that observed anti-infective activity will translate to outcomes in a therapeutic context. We give worked examples of tentative pharmacokinetic assessment of some well-known medicinal plants.
PubMed: 31736910
DOI: 10.3389/fmicb.2019.02470 -
Microbial Cell Factories Nov 2017Efficient growth of E. coli, especially for production of recombinant proteins, has been a challenge for the biotechnological industry since the early 1970s. By... (Review)
Review
Efficient growth of E. coli, especially for production of recombinant proteins, has been a challenge for the biotechnological industry since the early 1970s. By employing multiple approaches, such as different media composition, various growth strategies and specific genetic manipulations, it is now possible to grow bacteria to concentrations exceeding 100 g/L and to achieve high concentrations of recombinant proteins. Although the growth conditions are carefully monitored and maintained, it is likely that during the growth process cells are exposed to periodic stress conditions, created by fluctuations in pH, dissolved oxygen, temperature, glucose, and salt concentration. These stress circumstances which can occur especially in large volume bioreactors, may affect the growth and production process. In the last several years, it has been recognized that small non-coding RNAs can act as regulators of bacterial gene expression. These molecules are found to be specifically involved in E. coli response to different environmental stress conditions; but so far, have not been used for improving production strains. The review provides summary of small RNAs identified on petri dish or in shake flask culture that can potentially affect growth characteristics of E. coli grown in bioreactor. Among them MicC and MicF that are involved in response to temperature changes, RyhB that responds to iron concentration, Gady which is associated with lower pH, Sgrs that is coupled with glucose transport and OxyS that responds to oxygen concentration. The manipulation of some of these small RNAs for improving growth of E. coli in Bioreactor is described in the last part of the review. Overexpression of SgrS was associated with improved growth and reduced acetate expression, over expression of GadY improved cell growth at acidic conditions and over expression of OxyS reduced the effect of oxidative stress. One of the possible advantages of manipulating sRNAs for improving cell growth is that the modifications occur at a post-translational level. Therefore, the use of sRNAs may exert minimal effect on the overall bacterial metabolism. The elucidation of the physiological role of newly discovered sRNAs will open new possibilities for creating strains with improved growth and production capabilities.
Topics: Acetates; Batch Cell Culture Techniques; Bioreactors; Escherichia coli; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; RNA, Bacterial; RNA, Small Untranslated; Recombinant Proteins; Stress, Physiological; Temperature
PubMed: 29137641
DOI: 10.1186/s12934-017-0810-x -
PHAGE (New Rochelle, N.Y.) Dec 2021Bacteriophage plaque enumeration is a critical step in a wide array of protocols. The current gold standard for plaque enumeration on Petri dishes is through manual...
Bacteriophage plaque enumeration is a critical step in a wide array of protocols. The current gold standard for plaque enumeration on Petri dishes is through manual counting. However, this approach is not only time-consuming and prone to human error but also limited to Petri dishes with countable number of plaques resulting in low throughput. We present OnePetri, a collection of trained machine learning models and open-source mobile application for the rapid enumeration of bacteriophage plaques on circular Petri dishes. When compared against the current gold standard of manual counting, OnePetri was ∼30 × faster. Compared against other similar tools, OnePetri had lower relative error (∼13%) than Plaque Size Tool (PST) (∼86%) and CFU.AI (∼19%), while also having significantly reduced detection times over PST (1.7 × faster). The OnePetri application is a user-friendly platform that can rapidly enumerate phage plaques on circular Petri dishes with high precision and recall.
PubMed: 36159886
DOI: 10.1089/phage.2021.0012 -
Journal of Fungi (Basel, Switzerland) Nov 2018has several advantages as an experimental host for the study of infectious diseases. Worms are easily maintained and propagated on bacterial lawns. The worms can be... (Review)
Review
has several advantages as an experimental host for the study of infectious diseases. Worms are easily maintained and propagated on bacterial lawns. The worms can be frozen for long term storage and still maintain viability years later. Their short generation time and large brood size of thousands of worms grown on a single petri dish, makes it relatively easy to maintain at a low cost. The typical wild type adult worm grows to approximately 1.5 mm in length and are transparent, allowing for the identification of several internal organs using an affordable dissecting microscope. A large collection of loss of function mutant strains are readily available from the genetic stock center, making targeted genetic studies in the nematode possible. Here we describe ways in which this facile model host has been used to study , an opportunistic fungal pathogen that poses a serious public health threat.
PubMed: 30405043
DOI: 10.3390/jof4040123 -
Integrative Biology : Quantitative... Jul 2018Improving fluorescent proteins through the use of directed evolution requires robust techniques for screening large libraries of genetic variants. Here we describe an...
Improving fluorescent proteins through the use of directed evolution requires robust techniques for screening large libraries of genetic variants. Here we describe an effective and relatively low-cost system for screening libraries of fluorescent protein variants for improved photostability in the context of colonies on a Petri dish. Application of this system to the yellow fluorescent protein mCitrine, led to the development of Citrine2 with improved photostability and similar high fluorescent brightness. The photobleaching robot was constructed using a Lego Mindstorms Ev3 set and a xenon arc lamp, which together create even and high irradiance over an entire Petri dish through patterned illumination.
Topics: Bacterial Proteins; Crystallography, X-Ray; Escherichia coli; HeLa Cells; Humans; Light; Luminescent Proteins; Models, Biological; Mutation; Photobleaching; Photochemistry; Plasmids; Robotics
PubMed: 29897363
DOI: 10.1039/c8ib00063h