A functional genetic toolbox for human tissue-derived organoids

Human organoid systems recapitulate key features of organs offering platforms for modelling developmental biology and disease. Tissue-derived organoids have been widely used to study the impact of extrinsic niche factors on stem cells. However, they are rarely used to study endogenous gene function due to the lack of efficient gene manipulation tools. Previously, we established a human foetal lung organoid system (Nikolić et al., 2017). Here, using this organoid system as an example we have systematically developed and optimised a complete genetic toolbox for use in tissue-derived organoids. This includes 'Organoid Easytag' our efficient workflow for targeting all types of gene loci through CRISPR-mediated homologous recombination followed by flow cytometry for enriching correctly-targeted cells. Our toolbox also incorporates conditional gene knock-down or overexpression using tightly-inducible CRISPR interference and CRISPR activation which is the first efficient application of these techniques to tissue-derived organoids. These tools will facilitate gene perturbation studies in tissue-derived organoids facilitating human disease modelling and providing a functional counterpart to many on-going descriptive studies, such as the Human Cell Atlas Project.

Real-Time Fluorometric Isothermal LAMP Assay for Detection of Chlamydia pecorum in Rapidly Processed Ovine Abortion Samples: A Veterinary Practitioner’s Perspective

Traditional methods of detecting Chlamydia pecorum in tissue samples such as polymerase chain reaction or cell culture are laborious and costly. We evaluated the use of a previously developed C. pecorum LAMP assay using minimally processed ovine samples. Cotyledon (n = 16), foetal liver (n = 22), foetal lung (n = 2), and vaginal (n = 6) swabs, in addition to cotyledon (n = 6) and foetal liver (n = 8) tissue samples, were rapidly processed and used for LAMP testing without DNA extraction. Overall, LAMP test results were highly congruent with the in-house reference qPCR, with 80.43% (37/46; 72.73% positive agreement (PA); 84.75% negative agreement (NA)) overall agreeance for swab samples, and 85.71% (12/14; 80% PA; 88.89% NA) overall agreeance for tissue samples. Out of the 11 total discrepant results, discrepancy was mainly observed in samples (n = 10) with less than 100 copies/µL C. pecorum DNA. While sensitivity could be improved, the simplicity, low cost, and accuracy of detection makes this test amenable for use at point-of-care for detecting C. pecorum in sheep.

Optimisation of rapid untargeted nanopore DNA virus metagenomics using cell cultures and calves experimentally infected with bovine herpes virus-1

Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in cattle in Ireland, and internationally. This disease is caused by many well-known, and an ever-increasing number of newly associated viruses and bacteria. Consequently, diagnosis of BRD pathogens by targeted real-time polymerase chain reaction (qPCR) diagnostics is too expensive and slow to enable a same-day response that is targeted at the causative pathogen(s). To address this, we developed a same-day, sample to result, untargeted metagenomic MinION sequencing protocol for the identification of DNA viruses associated with BRD from nasal swabs. The procedure comprises non-viral nucleic acid depletion, nucleic acid extraction, rapid transposase-based tagmentation with barcoded adapters, non-biased PCR amplification of tagmented nucleic acid, sequencing on a MinION device, then rapid analysis of resulting sequences on cloud-based software EPI2ME WIMP. The protocol was developed using BoHV1-infected foetal lung cell cultures where we achieved 96% enrichment of the BoHV-1 sequence. Subsequently, the protocol was successfully applied to untargeted detection of BoHV-1 in nasal swabs from calves experimentally challenged with BoHV-1.

Microscopic Studies Of The Foetal Lung Development In The OneHumped Camel (Camelus dromedarius) Obtained From Kano Abattoir

Eighty – seven foetal lung samples from camels (Camelus dromedarius) were collected at Kano abattoir to study lung development. Four phases of the lung development were observed as follows; pseudo-glandular phase was between 10.5 cm to 38.2 cm crown-rump length, with endodermal buds and prominent mesenchymal cells. Canalicular phase was observed between 38.7 cm to 62.2 cm crownrump length and was characterized by thinning of the endodermal buds and invasion of capillaries. Saccular phase was noticed at 65.6 cm to 82.6 cm crown-rump length when thick intercellular septa were noticed. Alveolar phase was noticed between 85.9 cm to 121 cm crown-rump length when primitive alveolar was noticed. This study has established phases of lung development in the camel and serves as baseline information for scientific knowledge. Keywords: Foetal lung, camel (Camelus dromedarius), crown-rump length, lung development and Kano abattoir.

Vanishing Non-immune Hydrops in Giant Chorioangioma of Placenta

Giant Chorioangioma of placenta is a rare nontrophoblastic tumour of placenta. It may lead to various maternal and foetal complications like massive antepartum haemorrhage, sudden intrauterine foetal demise and non-immune hydrops, although in few cases mother and the foetus remain unaffected. This report is of a 35-year-old G3P1L1A1, presented to hospital at 32 weeks gestation with pain abdomen followed by watery discharge from vagina. Ultrasonography at 30 weeks revealed a huge mass on anterior wall with placenta on posterior wall of uterus although her previous antenatal sonography did not reveal any abnormality either in the foetus or in placenta. Diagnosis of preterm rupture of membranes was confirmed. Hence, she was kept on conservative management; received antibiotics and steroids for foetal lung maturity. Subsequently, the foetus developed mild, steady non-immune hydrops probably due to high output cardiac failure as Values of Middle Cerebral Artery’s Peak Systolic Velocity (MCA-PSV) were within normal limits. Biophysical profile and nonstress test were normal. Guarded foetal prognosis was given due to non-immune hydrops but she delivered a normal female baby with good Appearance, Pulse, Grimace, Activity and Respiration (APGAR) score with huge chorioangioma of placenta. Although rare, chorioangiomas of placenta should be kept in differential diagnosis of non-immune hydrops that needs regular foetal surveillance and timely intervention in affected foetuses to increase survival after birth.

Methods of detection and prevention of preterm labour and the PAMG-1 detection test: a review

ObjectivesPreterm labour is the leading cause of hospitalization during pregnancy. In France, it results in more than 60,000 births before 37 weeks of gestation every year. Recent studies suggest that detection of placental α-microglobulin-1 (PAMG-1) in vaginal secretions among women presenting symptoms of preterm labour with intact membranes has good predictive value for the onset of spontaneous preterm delivery within 7 days. The test is especially interesting, in that the repetition of antenatal corticosteroids for foetal lung maturation is no longer recommended in France and the effect of the initial administration is most beneficial in the 24 h to 7 days afterwards.MethodsWe included all studies listed in PubMed and clinicaltrials.gov with the terms “PAMG-1” and either “preterm labor” or “preterm labour”, while excluding all studies on the subject of “rupture of the membranes” from 2000 through 2017. Ten studies were thus included.ResultsIn women who had both the PAMG-1 and foetal fibronectin test, the PAMG-1 test was statistically superior to the measurement of cervical length for positive predictive value (p<0.0074), negative predictive value (p=0.0169) and specificity (p<0.001) for the prediction of spontaneous preterm delivery within 7 days.ConclusionThe use of PAMG-1 may make it possible to target the women at risk with a shortened cervix on ultrasound (<25 mm) those with an imminent preterm delivery and therefore to adapt management, especially the administration of antenatal corticosteroid therapy.

Pentagalloylglucose, isolated from the leaf extract of Anacardium occidentale L., could elicit rapid and selective cytotoxicity in cancer cells

ABSTRACT Background The leaf of Anacardium occidentale L. has been a component of many herbal recipes in South-Western Nigeria. The work reported herein, therefore, explored the phytochemical composition of this plant and the potential anti-cancer activity of an isolated chemical constituent. Methods Phytochemical methods (including chromatographic analysis) combined with spectroscopic and spectrometric analyses (IR, HRMS and NMR (1D and 2D)) were used to identify chemical constituents. Cytotoxic effects were determined using the MTT viability assay and bright-field imaging. Induction of oxidative stress was determined using the fluorescence-based 2′,7′-dichlorofluorescein diacetate (DCFDA) assay. Results For the first time in the plant, Compound 1 was isolated from the leaf extract and identified as pentagalloylglucose. Compound 1 was significantly cytotoxic against the cancer cell lines HeLa (human cervical adenocarcinoma cell line) and MRC5-SV2 (human foetal lung cancer cell line), with IC50 of 71.45 and 52.24 μg/ml, respectively. The selectivity index (SI) for Compound 1 was 1.61 (IC50 against the normal human foetal lung fibroblast cell line MRC-5 was 84.33μg/ml), demonstrating better cancer cell-selectivity compared to doxorubicin with a SI of 1.28. The cytotoxic activity of Compound 1 in HeLa cells was also rapid, as shown by its concentration- and time-dependent 3 h and 6 h cytotoxicity profiles, an effect not observed with doxorubicin. Generation of reactive oxygen species at high concentrations of pentagalloylglucose to induce oxidative stress in cancer cells was identified as a mechanistic event that led to or resulted from its cytotoxicity. Conclusions We suggest that pentagalloylglucose is selectively cytotoxic to cancer cells, and at high concentrations could exhibit pro-oxidant effects in those cells, as opposed to its general anti-oxidant effects in cells. Also, the presence of Compound 1 (pentagalloylglucose) in the plant and its cancer cell-selective cytotoxicity provide some rationale for the ethno-medicinal use of the plant’s leaf extract for treating diseases associated with excessive cell proliferation. Further studies are required to dissect the molecular mechanisms and players differentially regulating the biphasic anti-oxidant and pro-oxidant effects of pentagalloylglucose in normal and cancer cells.

Obstetrical and intensive care strategies in a high-risk pregnancy with critical respiratory failure due to COVID-19: a case report

BackgroundWith the disease burden increasing daily, there is a lack of evidence regarding the impact of COVID-19 in pregnancy. Healthy pregnant women are still not regarded as a susceptible group despite physiological changes that make pregnant women more vulnerable to severe infection. However, high-risk pregnancies may be associated with severe COVID-19 disease with respiratory failure, as outlined in this report. We discuss the importance of timely delivery and antenatal steroid administration in a critically ill patient.CaseA 27-year-old pregnant woman (1-para) with type I diabetes, morbid obesity, hypothyroidism and a previous Caesarean section, presented with critical respiratory failure secondary to COVID-19 at 32 weeks of gestation. A preterm emergency Caesarean section was performed, after steroid treatment for foetal lung maturation. The patient benefited from prone positioning however, transient acute renal injury, rhabdomyolysis and sepsis led to prolonged intensive care and mechanical ventilation for 26 days post-Caesarean. The baby had an uncomplicated recovery.ConclusionCOVID-19 infection in high-risk pregnancies may result in severe maternal-neonatal outcomes such as critical respiratory failure requiring mechanical ventilation and premature termination of the pregnancy. Antenatal steroids may be of benefit for foetal lung maturation but should not delay delivery in severe cases.

Orthotopic foetal lung tissue direct injection into lung showed a preventive effect against paraquat-induced acute lung injury in mice

OBJECTIVES Lung transplantation is the only effective therapy for patients with end-stage lung disease but an organ shortage crisis necessitates the development of alternative therapies. Recent studies have highlighted the potential of foetal tissue transplantation to facilitate the regeneration of vital organs such as liver that have been damaged by lethal diseases. Herein, with the aim of restoring pulmonary function, we hypothesized that allogenic foetal lung tissue implantation would attenuate severe respiratory failure. METHODS Lung tissue from the foetuses of pregnant green fluorescent protein-C57BL/6 mice at 13.5 days of gestation was injected into the left lungs of recipient mice. Severe lung injury was induced by paraquat, and we analysed the survival rate and pathohistological findings after 1 month. RESULTS The survival rate of the therapy group was 39%, which was significantly higher than the vehicle group at 5.9% (P = 0.034). Immunochemical staining showed that positive cytoplasmic stained cells with anti-interleukin-10 antibody were identified in the gland-like structure of embryonic day 13.5 foetal lung. At 4 weeks after orthotopic implantation, haematoxylin and eosin staining showed reduced lung inflammatory cells, reduced lung oedema and increased active cell proliferation of foetal lung cells. Lung injury score showed that the airway septal thickening revealed statistically significant differences between vehicle and foetal lung therapy (P &lt; 0.001). CONCLUSIONS Immature foetal lungs improved the survival rate of mice with paraquat-induced severe lung injury, establishing the need for systematic follow-up studies. The anti-inflammatory cytokine in the tissue from embryonic day 13.5 foetal lung might suppress severe lung injury.

Antenatal corticosteroid administration for foetal lung maturation

Antenatal corticosteroids are an essential component in the management of women at risk for preterm labour. They promote lung maturation and reduce the risk of other preterm neonatal complications. This narrative review discusses the contentious issues and controversies around the optimal use of antenatal corticosteroids and their consequences for both the mother and the neonate. The most recent evidence base is presented.