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Endeavour 2019Richard Julius Petri's status as inventor of the culture dish that bears his name has been subject to a number of challenges over the years. Both those bacteriologists...
Richard Julius Petri's status as inventor of the culture dish that bears his name has been subject to a number of challenges over the years. Both those bacteriologists who claimed self-recognition for the invention, and those to whom it was attributed by their various advocates were all contemporaries of Petri. The evidence assembled here indicates that no single individual-including Petri-ought to be accorded credit for the inception of that shallow, circular, covered culture dish which, it transpires, is a simultaneous invention made by half a dozen bacteriologists active in the mid-1880s and ultimately owes its emergence to the prevailing bacteriological zeitgeist.
Topics: Bacteriology; Culture Media; History, 19th Century; Humans; Inventions
PubMed: 31030894
DOI: 10.1016/j.endeavour.2019.04.001 -
Vaccine Jan 2017Malaria in pregnancy is associated with significant morbidity in pregnant women and their offspring. Plasmodium falciparum infected erythrocytes (IE) express VAR2CSA... (Comparative Study)
Comparative Study
BACKGROUND
Malaria in pregnancy is associated with significant morbidity in pregnant women and their offspring. Plasmodium falciparum infected erythrocytes (IE) express VAR2CSA that mediates binding to chondroitin sulphate A (CSA) in the placenta. Two VAR2CSA-based vaccines for placental malaria are in clinical development. The purpose of this study was to evaluate the robustness and comparability of binding inhibition assays used in the clinical development of placental malaria vaccines.
METHODS
The ability of sera from animals immunised with different VAR2CSA constructs to inhibit IE binding to CSA was investigated in three in vitro assays using 96-well plates, petri dishes, capillary flow and an ex vivo placental perfusion assay.
RESULTS
The inter-assay variation was not uniform between assays and ranged from above ten-fold in the flow assay to two-fold in the perfusion assay. The intra-assay variation was highest in the petri dish assay. A positive correlation between IE binding avidity and the level of binding after antibody inhibition in the petri dish assay indicate that high avidity IE binding is more difficult to inhibit. The highest binding inhibition sensitivity was found in the 96-well and petri dish assays compared to the flow and perfusion assays where binding inhibition required higher antibody titers.
CONCLUSIONS
The inhibitory capacity of antibodies is not easily translated between assays and the high sensitivity of the 96-well and petri dish assays stresses the need for comparing serial dilutions of serum. Furthermore, IE binding avidity must be in the same range when comparing data from different days. There was an overall concordance in the capacity of antibody-mediated inhibition, when comparing the in vitro assays with the perfusion assay, which more closely represents in vivo conditions. Importantly the ID1-ID2a protein in a liposomal formulation, currently in a phase I trial, effectively induced antibodies that inhibited IE adhesion in placental tissue.
Topics: Animals; Antibodies, Protozoan; Antigens, Protozoan; Cell Adhesion; Chondroitin Sulfates; Cytological Techniques; Drug Discovery; Erythrocytes; Female; Malaria Vaccines; Malaria, Falciparum; Mice, Inbred C57BL; Placenta Diseases; Pregnancy; Rabbits; Rats, Wistar; Reproducibility of Results
PubMed: 28012775
DOI: 10.1016/j.vaccine.2016.12.028 -
Zootaxa Sep 2022The life history of Erotylina jaspidea (Erichson, 1847) (Coleoptera, Erotyloidea, Erotylidae, Erotylini) is described. A female specimen was found in an Atlantic Forest...
The life history of Erotylina jaspidea (Erichson, 1847) (Coleoptera, Erotyloidea, Erotylidae, Erotylini) is described. A female specimen was found in an Atlantic Forest remnant in Northeast Brazil. After oviposition, individuals were reared in Petri dish and terrarium, feeding on basidiomes of Lentinus substrictus (Bolton) Zmitr. Kovalenko, Favolus tenuiculus P. Beauv (Polyporaceae) and an unidentified resupinate fungus. Growth and feeding behaviors were regularly observed. We provide information on the observed life history stages, together with morphological descriptions, and photographs of eggs, larvae, pupae and adults. We compared our description of the teneral E. jaspidea to species of similar color pattern. Furthermore, we discuss hypotheses about larval defensive behavior and total instar durations in E. jaspidea and other Erotylinae representatives. The present work is the first to provide a description for the life history of a species of the genus Erotylina.
Topics: Animals; Coleoptera; Female; Forests; Larva; Oviposition; Pupa
PubMed: 36095671
DOI: 10.11646/zootaxa.5182.5.6 -
Gels (Basel, Switzerland) May 2023Macroscopic spatial patterns were formed in calcium alginate gels when a drop of a calcium nitrate solution was placed on the center of a sodium alginate solution on a...
Macroscopic spatial patterns were formed in calcium alginate gels when a drop of a calcium nitrate solution was placed on the center of a sodium alginate solution on a petri dish. These patterns have been classified into two groups. One is multi-concentric rings consisting of alternating cloudy and transparent areas observed around the center of petri dishes. The other is streaks extending to the edge of the petri dish, which are formed to surround the concentric bands between the concentric bands and the petri dish edge. We have attempted to understand the origins of the pattern formations using the properties of phase separation and gelation. The distance between two adjacent concentric rings was roughly proportional to the distance from where the calcium nitrate solution was dropped. The proportional factor increased exponentially for the inverse of the absolute temperature of the preparation. The also depended on the concentration of alginate. The pattern characteristics in the concentric pattern agreed with those in the Liesegang pattern. The paths of radial streaks were disturbed at high temperatures. The length of these streaks shortened with increasing alginate concentration. The characteristics of the streaks were similar to those of crack patterns resulting from inhomogeneous shrinkage during drying.
PubMed: 37367115
DOI: 10.3390/gels9060444 -
Biomicrofluidics Jan 2021Many wound-healing assays are used in cell biology and biomedicine; they are often labor intensive and/or require specialized and costly equipment. We describe a...
Many wound-healing assays are used in cell biology and biomedicine; they are often labor intensive and/or require specialized and costly equipment. We describe a contactless method to create wounds with any imaginable 2D pattern in cell monolayers using the micro-jets of either media or an immiscible and biocompatible fluorocarbon (i.e., FC40). We also combine this with another method that allows automation and multiplexing using standard Petri dishes. A dish is filled with a thin film of media overlaid with FC40, and the two liquids are reshaped into an array of microchambers within minutes. Each chamber in such a grid is isolated from others by the fluid walls of FC40. Cells are now added, allowed to grow into a monolayer, and wounds are created using the microjets; then, healing is monitored by microscopy. As arrays of chambers can be made using media and Petri dishes familiar to biologists, and as dishes fit seamlessly into their incubators, microscopes, and workflows, we anticipate that this assay will find wide application in wound healing.
PubMed: 33598064
DOI: 10.1063/5.0043312 -
ACS Applied Materials & Interfaces May 2020Polysiloxane is a desirable material for the fabrication of devices in microfluidics, lab-on-a-chip, and microelectromechanical systems, but direct patterning of...
Polysiloxane is a desirable material for the fabrication of devices in microfluidics, lab-on-a-chip, and microelectromechanical systems, but direct patterning of microstructures using liquid polysiloxane resins would require adequate rheological and chemical properties of the resins. In this work, we developed a simple method to fabricate planar microstructures consisting of polysiloxane using commercially available liquid polysiloxane resins without changing their properties. We used a direct ink writing (DIW) printer to dispense curable liquid polysiloxane (with the viscosity in the range of 1-100 Pa·s) in a liquid immiscible with the resins (such as methanol, ethanol, and isopropanol). The contact angle (θ) of the dispensed polysiloxane on the Petri dish increased from 20° in air to 100° in methanol, ethanol, and isopropanol. The increase in the contact angles allowed maintaining the structures of patterned polysiloxane until curing, and the embedding liquid was readily removed by evaporation. We termed this method as embedded ink writing (EIW). The effects of curing time (τ) and nozzle speed () on the width of the printed filament () were evaluated. EIW achieved the minimum width of the printed filament of 65 μm. EIW enabled direct writing of polysiloxane resins and should find applications in fabricating microfluidic devices, flexible wearables, and soft actuators.
PubMed: 32319285
DOI: 10.1021/acsami.0c03011 -
Biomolecules Nov 2021Microbial biofilms formed by pathogenic and antibiotic-resistant microorganisms represent a serious threat for public health in medicine and many industrial branches....
Microbial biofilms formed by pathogenic and antibiotic-resistant microorganisms represent a serious threat for public health in medicine and many industrial branches. Biofilms are involved in many persistent and chronic infections, the biofouling of water and food contamination. Therefore, current research is involved in the development of new treatment strategies. Biofilm is a complex system, and thus all aspects of the measurement and monitoring of its growth and eradication in various conditions, including static and dynamic flow, are issues of great importance. The antibiofilm character of rhamnolipid mixtures produced by four strains was studied under different conditions. For this purpose, the biofilm of opportunistic pathogen was used and treated under static conditions (microscope glass coverslip in a Petri dish) and under dynamic conditions (a single-channel flow cell). The results show that the biological activity of rhamnolipids depends both on their properties and on the conditions of the biofilm formation. Therefore, this aspect must be taken into account when planning the experimental or application design.
Topics: Basidiomycota; Biofilms; Glycolipids
PubMed: 34827725
DOI: 10.3390/biom11111727 -
Micromachines Sep 2020In this paper, we report on a novel biocompatible micromechanical bioreactor (actuator and sensor) designed for the in situ manipulation and characterization of live...
In this paper, we report on a novel biocompatible micromechanical bioreactor (actuator and sensor) designed for the in situ manipulation and characterization of live microtissues. The purpose of this study was to develop and validate an application-targeted sterile bioreactor that is accessible, inexpensive, adjustable, and easily fabricated. Our method relies on a simple polydimethylsiloxane (PDMS) molding technique for fabrication and is compatible with commonly-used laboratory equipment and materials. Our unique design includes a flexible thin membrane that allows for the transfer of an external actuation into the PDMS beam-based actuator and sensor placed inside a conventional 35 mm cell culture Petri dish. Through computational analysis followed by experimental testing, we demonstrated its functionality, accuracy, sensitivity, and tunable operating range. Through time-course testing, the actuator delivered strains of over 20% to biodegradable electrospun poly (D, L-lactide-co-glycolide) (PLGA) 85:15 non-aligned nanofibers (~91 µm thick). At the same time, the sensor was able to characterize time-course changes in Young's modulus (down to 10-150 kPa), induced by an application of isopropyl alcohol (IPA). Furthermore, the actuator delivered strains of up to 4% to PDMS monolayers (~30 µm thick), simultaneously characterizing their elastic modulus up to ~2.2 MPa. The platform repeatedly applied dynamic (0.23 Hz) tensile stimuli to live Human Dermal Fibroblast (HDF) cells for 12 hours (h) and recorded the cellular reorientation towards two angle regimes, with averages of -58.85° and +56.02°. The device biocompatibility with live cells was demonstrated for one week, with no signs of cytotoxicity. We can conclude that our PDMS bioreactor is advantageous for low-cost tissue/cell culture micromanipulation studies involving mechanical actuation and characterization. Our device eliminates the need for an expensive experimental setup for cell micromanipulation, increasing the ease of live-cell manipulation studies by providing an affordable way of conducting high-throughput experiments without the need to open the Petri dish, reducing manual handling, cross-contamination, supplies, and costs. The device design, material, and methods allow the user to define the operational range based on their targeted samples/application.
PubMed: 32993158
DOI: 10.3390/mi11100892 -
Materials (Basel, Switzerland) Jul 2016The biodegradable cellular capsule, being prepared from simple vaporization of liquid marbles, is an ideal vehicle for the potential application of drug encapsulation...
The biodegradable cellular capsule, being prepared from simple vaporization of liquid marbles, is an ideal vehicle for the potential application of drug encapsulation and release. This paper reports the fabrication of cellular capsules via facile vaporization of Pickering emulsion marbles in an ambient atmosphere. Stable Pickering emulsion (water in oil) was prepared while utilizing dichloromethane (containing poly(l-lactic acid)) and partially hydrophobic silica particles as oil phase and stabilizing agents respectively. Then, the Pickering emulsion marbles were formed by dropping emulsion into a petri dish containing silica particles with a syringe followed by rolling. The cellular capsules were finally obtained after the complete vaporization of both oil and water phases. The technique of scanning electron microscope (SEM) was employed to research the microstructure and surface morphology of the prepared capsules and the results showed the cellular structure as expected. An in vitro drug release test was implemented which showed a sustained release property of the prepared cellular capsules. In addition, the use of biodegradable poly(l-lactic acid) and the biocompatible silica particles also made the fabricated cellular capsules of great potential in the application of sustained drug release.
PubMed: 28773693
DOI: 10.3390/ma9070572 -
Experimental & Applied Acarology Oct 2023Tetranychus urticae is an important pest worldwide. The auto-dissemination of spores of entomopathogenic fungi from an infected individual to conspecifics may be...
Tetranychus urticae is an important pest worldwide. The auto-dissemination of spores of entomopathogenic fungi from an infected individual to conspecifics may be important for controlling pests that can build high populations. The current study was carried out to determine the auto-dissemination of the entomopathogenic fungus Cordyceps fumosorosea strain PFs-1 (Priority®) between T. urticae females. The study consisted of four experiments. First, the efficacy of entomopathogenic fungus bioassays was assessed in Petri dishes (experiment 1) and on potted bean plants (experiment 2). In the auto-dissemination trials (experiments 3 and 4, in Petri dishes and on potted plants, respectively), contaminated adult females (1-5) were released among uncontaminated females (10 individuals). All experiments were carried out separately, and observations were made on days 3, 5, and 7. In exp. 1, the control was different from Priority on all observation days. In exp. 2, the average number of surviving individuals in the control was significantly higher than in the Priority treatment. In the auto-dissemination experiments, as the number of contaminated individuals increased, the mortality rate of uncontaminated individuals also increased, in exp. 3 (Petri dishes) on all observation days, and in exp. 4 (potted plants) only on days 5 and 7. The median lethal time (LT50) decreased as the number of individuals contaminated with Priority increased in both Petri dish and pot trials. Consequently, the effectiveness of biological control may increase with the occurrence of indirect contamination from infected to uncontaminated individuals.
Topics: Humans; Female; Animals; Tetranychidae; Pest Control, Biological; Cordyceps; Fabaceae
PubMed: 37787901
DOI: 10.1007/s10493-023-00845-9