A Bioprinted Heart-on-a-Chip with Human Pluripotent Stem Cell-Derived Cardiomyocytes for Drug Evaluation

In this work, we show that valve-based bioprinting induces no measurable detrimental effects on human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The aim of the current study was three-fold: first, to assess the response of hiPSC-CMs to several hydrogel formulations by measuring electrophysiological function; second, to customise a new microvalve-based cell printing mechanism in order to deliver hiPSC-CMs suspensions, and third, to compare the traditional manual pipetting cell-culture method and cardiomyocytes dispensed with the bioprinter. To achieve the first and third objectives, iCell2 (Cellular Dynamics International) hiPSC-CMs were used. The effects of well-known drugs were tested on iCell2 cultured by manual pipetting and bioprinting. Despite the results showing that hydrogels and their cross-linkers significantly reduced the electrophysiological performance of the cells compared with those cultured on fibronectin, the bio-ink droplets containing a liquid suspension of live cardiomyocytes proved to be an alternative to standard manual handling and could reduce the number of cells required for drug testing, with no significant differences in drug-sensitivity between both approaches. These results provide a basis for the development of a novel bioprinter with nanolitre resolution to decrease the required number of cells and to automate the cell plating process.

Multiple Cross Displacement Amplification Coupled with Lateral Flow Biosensor (MCDA-LFB) for rapid detection of Legionella pneumophila

Background Legionella pneumophila is an opportunistic waterborne pathogen of significant public health problems, which can cause serious human respiratory diseases (Legionnaires’ disease). Multiple cross displacement amplification (MCDA), a isothermal nucleic acid amplification technique, has been applied in the rapid detection of several bacterial agents. In this report, we developed a MCDA coupled with Nanoparticles-based Lateral Flow Biosensor (MCDA-LFB) for the rapid detection of L. pneumophila. Results A set of 10 primers based on the L. pneumophila specific mip gene to specifically identify 10 different target sequence regions of L. pneumophila was designed. The optimal time and temperature for amplification are 57 min and 65 °C. The limit of detection (LoD) is 10 fg in pure cultures of L. pneumophila. No cross-reaction was obtained and the specificity of MCDA-LFB assay was 100%. The whole process of the assay, including 20 min of DNA preparation, 35 min of L. pneumophila-MCDA reaction, and 2 min of sensor strip reaction, took a total of 57 min (less than 1 h). Among 88 specimens for clinical evaluation, 5 (5.68%) samples were L. pneumophila-positive by MCDA-LFB and traditional culture method, while 4(4.55%) samples were L. pneumophila-positive by PCR method targeting mip gene. Compared with culture method, the diagnostic accuracy of MCDA-LFB method was higher. Conclusions In summary, the L. pneumophila-MCDA-LFB method we successfully developed is a simple, fast, reliable and sensitive diagnostic tool, which can be widely used in basic and clinical laboratories.

Antagonistic screening of Trichoderma spp. isolated from patchouli rhizosphere

The objective of this research was to determine the antagonistic activity of Trichoderma spp. isolated from patchouli rhizosphere (Pogostemon cablin Benth.). Another objective was to perform antagonistic screening of these fungi to inhibit the growth of the wilted pathogen Fusarium spp. In vitro research was conducted in the Laboratory of Plant Pathology, Universitas Syiah Kuala, from January to June 2020. The study used a completely randomised design with five treatments and three replications. The antagonistic screening was carried out by using the dual culture method of Trichoderma spp. against Fusarium spp. with the medium of Potato Dextrose Agar (PDA). The result showed that five isolates of Trichoderma have different antagonistic percentages in inhibiting the Fusarium. The highest antagonistic activity was found from isolate 2 and the lowest value was shown by isolate 3.

Assessment of bioscompatibility of isocyanurate-containing polyurethanes with ifosphamide by in vivo and in vitro methods.

Background. The creation of polymeric composite materials with pronounced biological activity, which are able to act as implants with local prolonged action of the immobilized substance can be widely used in medical practice. Objective. Study of cellular reactions of surrounding tissues of experimental animals to implantation of polymeric composite materials based on isocyanurate-containing polyurethanes with ifosfamide, study of histotoxicity of the obtained materials by tissue culture method. Methods. Polymeric composite materials based on isocyanate-containing polyurethanes without and with ifosfamide were implanted into the body of white laboratory Wistar rats. Cellular responses of the organism and possible changes in the structure of test specimens after implantation were studied by light microscopy by analysis of histological micropreparations. In order to study the peculiarities of the dynamics of growth and development of fibroblastic elements, the method of tissue culture was used. Results. Conducted biological studies by in vivo and in vitro methods allowed to evaluate the effect of immobilized ifosfamide in the structure of isocyanurate-containing polyurethanes on cellular reactions of surrounding tissues during implantation in experimental animals, as well as the effect of extracts from developed polymer samples on cultured cell growth. Conclusion. It was found that the implantation of isocyanurate-containing polyurethanes with ifosfamide led to the development of intense cellular reactions in the area of implant placement, primarily the reaction of round cell elements. The presence of ifosfamide in the structure of the polymeric implantation material probably affected the proliferation of cellular elements, inhibited regenerative processes in the early stages of the study and delayed the formation of a mature connective tissue capsule around the implanted samples. The tissue culture method showed that when making an extract of isocyanurate-containing polyurethanes with ifosfamide in the culture medium, there was a large variability of cell forms, which led to the appearance of macrophage-like elements.

Report of some cases with chromosomal mosaicism in prenatal diagnosis and the corresponding results after birth

Chromosomal mosaicism in prenatal diagnosis is a complex problem that confuses the perception of true mosaicism or pseudomosaicismand often causes difficulties in genetic counseling. In this study, the authors reported 5 cases of chromosomal mosaicism in prenatal karyotype diagnosisand compared them withthe corresponding karyotype results of children after birth. Amniotic fluid and peripheral blood cells were prepared chromosomal metaphase by culture method and chromosomal analysis according to ISCN 2016 standards. Samples were collected and analysed at Hanoi Medical University Hospital from 2017 to 2020. There were 3 cases of abnormal prenatal chromosomal mosaicism, but the postnatal results were normal, two cases of abnormal prenatal chromosome mosaicism, but had abnormal peripheral blood postnatal chromosome results. These results, together with discussion, will provide more valuable information for the prognosis of chromosome mosaicism cases in prenatal diagnosis and give better genetic counseling for the patients.

Development of An Efficient Protocol for Rapid Propagation of Curculigo orchioides Using Leaf Explant Culture

Curculigo orchioides is one of the most common medicinal plants used by diverse cultures and tribal groups. The roots of the plant are used medicinally in Asian countries. Curculigo orchioides have the ability to regenerate through seeds and tubers, but the regeneration rate is low. Plant tissue culture method was believed to have potential for rapid multiplication of this medicinal plant. An efficient protocol for rapid propagation of Curculigo orchioides, of the family Amaryllidaceae, was developed using leaf explants culture. The leaf explants (1 cm x 1 cm squares) cultured on Murashige and Skoog (MS) basal medium were supplemented with various concentrations and combinations of auxins and cytokinins with temperature 25 ± 2°C, relative humidity 85-90% and photoperiod of 12 hours light (2000-3000 lux). Callus induction was obtained within 4 weeks, 2,4-D at 3 mg/l formed profuse callus and the degree was found to be the highest (+++) among all the treatments. The best response to shoot induction, with maximum shoot number 5.33 (mean number of shoots per explant) was obtained using 1.0 mg/l 6-benzyl aminopurine (BAP) in combination with 1.0 mg/l Kinetin. In vitro shoots were induced for rooting on 0.5 mg/l of NAA supplemented medium. In order for seedlings propagated in vitro to adapt to natural conditions, plants were growned on a substrate coir: husk ash: sand (with the ratio of 0.5: 0.5: 1) in a greenhouse (humidity: 70%, temperature: 28-300C) gave 88.33% survival rate after 8 weeks of culture. With the results received, this is an effective approach to propagating Curculigo orchioides.

Optimised CO2-containing medium for in vitro culture and transportation of mouse preimplantation embryos without CO2 incubator

Conventional in vitro culture and manipulation of mouse embryos require a CO2 incubator, which not only increases the cost of performing experiments but also hampers the transport of embryos to the other laboratories. In this study, we established and tested a new CO2 incubator-free embryo culture system and transported embryos using this system. Using an Anaero pouch, which is a CO2 gas-generating agent, to increase the CO2 partial pressure of CZB medium to 4%–5%, 2-cell embryos were cultured to the blastocyst stage in a sealed tube without a CO2 incubator at 37°C. Further, the developmental rate to blastocyst and full-term development after embryo transfer were comparable with those of usual culture method using a CO2 incubator (blastocyst rate: 97% versus 95%, respectively; offspring rate: 30% versus 35%, respectively). Furthermore, using a thermal bottle, embryos were reliably cultured using this system for up to 2 days at room temperature, and live offspring were obtained from embryos transported in this simple and very low-cost manner without reducing the offspring rate (thermal bottle: 26.2% versus CO2 incubator: 34.3%). This study demonstrates that CO2 incubators are not essential for embryo culture and transportation and that this system provides a useful, low-cost alternative for mouse embryo culture and manipulation.

Potential of Streptomyces sp. in preventing the in vitro growth of Colletotrichum acutatum, the causative agent of infection in Capsicum annum L.

Red chilli plant (Capsicum annum L.) is one of the most popular vegetable crops in Indonesian society. One of them the pathogens attacks is Colletotrichum acutatum, a fungus causing anthracnose on red chilli. This study aims to determine the existence of Streptomyces sp. bacteria in the rhizosphere of the red chilli plant; the ability of Streptomyces sp. in inhibiting C. acutatum; Minimum Inhibitory Concentration (MIC) of Streptomyces isolates extracts in inhibiting C. acutatum; The Streptomyces isolation was carried out by dilution method using selective meida, namely Yeast Malt Agar. The Dual Culture method was used as an inhibition test between Streptomyces sp. and C. acutatum in vitro. A well diffusion method was used to test the effectiveness of the Streptomyces sp. and MIC filtrate concentration in inhibiting C. acutatum. The data obtained in this study were analyzed with Analysis of Varian (ANOVA) then continued with Duncan Multiple Range Test with 5% significance. Five Streptomyces isolates were found, namely Streptomyces sp.1, Streptomyces sp.2, Streptomyces sp.3, Streptomyces sp.4, and Streptomyces sp.5 in the rhizosphere of healthy C. annum L. plants in Daup Village, Kintamani District, Bangli Regency. Streptomyces sp. isolates. can significantly inhibit the growth of the fungus C. acuatum with inhibitory power ranging from 50.30% to 83.76%, Streptomyces sp.5 isolate was able to provide the highest percentage of inhibition in C. acutatum of 83.76 ± 2.91% with MIC 7% (v/v) with a diameter of 6.40 mm.

Potential Rhizopus spp. in control the growth of Aspergillus flavus FNCC6109 in broiler chicken concentrate feed

Aspergillus flavus contamination of agriculture in Indonesia can cause problems to animal health and productivity. Some factors can support the appearance of contamination in feed, especially temperature and humidity. The main objective of this research was to investigate potency of Rhizopus spp. on inhibit A. flavus FNCC6109 in broiler chicken concentrate feed. The experiments were conducted dual culture method and the inhibition test of the Rhizopus spp. filtrate culture was incubated for 3, 4 and 5 days on in vitro. The in vivo test was directly applied in broiler chicken concentrate feed which added Rhizopus spp. filtrate culture concentration at 10% (v/v), 20% (v/v), 30% (v/v), 40% (v/v), dan 50% (v/v). The results showed that the Rhizopus spp. filtrate culture significantly (P?0,05) to inhibit the growth of A. flavus FNCC6109 both in vitro and in vivo. The percentage inhibition of Rhizopus spp. filtrate culture incubated for 5 days showed 67,47±2,10% relatively better results than 3 and 4 days, and therefore was used in the in vivo. Application of 50% (v/v) Rhizopus spp. filtrate culture to the broiler chicken concentrate feed significantly reduced 82% population of A. flavus FNCC6109 after 15 days incubated relative to that of negative control (concentrate feed without addition Rhizopus spp. filtrate culture and A. flavus FNCC6109).

Incidence of Asymptomatic Bacteriuria in Pregnant Women

Background: Asymptomatic bacteriuria is the presence of bacteria in the properly collected urine of a patient that has no signs and symptoms of urinary tract infection. Aim: This study was carried out to determine the incidence of asymptomatic bacteriuria in pregnant women in Saveetha medical college, Thandalam, Tamil Nadu. Materials and Methods: A total of 250 pregnant women attending antenatal clinic at civil hospital, Saveetha medical college, over a period of 3 months, with age groups between 18 to 30 years agreed to enter the study and were clinically evaluated. All these women were asked to submit clean catch midstream urine samples and it was examined under the microscope and by culture method. Results: A total of 250 pregnant women included in our study, with varying age groups between 18 to 30 years and the highest incidence was seen in between the 26 to 30 age group. Asymptomatic bacteriuria was seen in 27.2% of the pregnant women. The prevalence of Escherichia coli was among the most dominant organism, followed by Staphylococcus aureus ,klebsiella and proteus species. Conclusion: The study showed 27.2% of the pregnant women to have asymptomatic bacteriuria. This can be reduced by screening the mothers in first trimester and routine urine culture test must be carried out.