Method for Large-scale Production of hIPSC Spheroids

Stem cell spheroids are rapidly becoming essential tools for a diverse array of applications ranging from tissue engineering to 3D cell models and fundamental biology. Given the increasing prominence of biotechnology, there is a pressing need to develop more accessible, efficient, and reproducible methods for producing these models. Various techniques such as hanging drop, rotating wall vessel, magnetic levitation, or microfluidics have been employed to generate spheroids. However, none of these methods facilitate the easy and efficient production of a large number of spheroids using a standard 6-well plate. Here, we present a novel method based on pellet culture (utilizing U-shaped microstructures) using a silicon mold produced through 3D printing, along with a detailed and illustrated manufacturing protocol. This technique enables the rapid production of reproducible and controlled spheroids (for 1× 106 cells, spheroids = 130 ± 10 μm) from human induced pluripotent stem cells (hIPSCs) within a short time frame (24 h). Importantly, the method allows the production of large quantities (2 × 104 spheroids for 1 × 106 cells) in an accessible and cost-effective manner, thanks to the use of a reusable mold. The protocols outlined herein are easily implementable, and all the necessary files for the method replication are freely available. Key features • Provision of 3D mold files (STL) to produce silicone induction device of spheroids using 3D printing. • Cost-effective, reusable, and autoclavable device capable of generating up to 1.2 × 104 spheroids of tunable diameters in a 6-well plate. • Spheroids induction with multiple hIPSC cell lines. • Robust and reproducible production method suitable for routine laboratory use.

A simple framework to distinguish 'individualistic' from a 'uniform rate' of ageing within or between study populations

Ageing is accompanied by a progressive decline in physiological functions. It is often argued that the rate of ageing differs between people and is 'highly individualistic'. This view is not unequivocally shared, and others have argued that the rate of ageing is rather 'uniform'. Distinguishing conclusively between these views requires longitudinal data, but these are difficult to obtain as they require decades of data collection from individuals. Here, a simple framework is proposed to assess in cross-sectional data whether in a given population the rate is 'highly individualistic' or rather 'uniform'. It is illustrated that an age-related decrease in the standard deviation (SD) of a certain parameter combined with a non-changing coefficient of variation (COVAR) reflects a 'uniform' rate of ageing, whilst an increase or decrease in COVAR with or without a concomitant increase in SD reflects a 'highly individualistic' rate of ageing. This framework is applied to some published data, focussing on muscle strength, power and physical function for the sake of illustration, and it is suggested that most studies do in fact show a 'highly individualistic' rate of ageing, perhaps apart from a 'uniform' rate of ageing in master athletes.

Local effects of printed logos and reflective striping fixed to firefighter clothing material packages under low radiation exposure

Notifications that related 1st degree burns to reflective striping and impermeable clothing elements did reach the investigators, while the mechanisms behind this phenomenon are still unclear. Material tests for thermal and evaporative resistance, and for heat transmission under dry and wet conditions at low radiation levels were done to evaluate the performance of protective clothing with and without printed logos or reflective striping. The results under the specified conditions showed reduction of heat loss capacity under impermeable elements from dry to wet conditions. Reflective surfaces, even when more impermeable, showed still lower heat transmission through the textile package than materials without striping under tested moisture and radiation combinations. It can be expected that the reported 1st degree burns were related to clothing design and tightness/fit rather than to reflective striping. However, due to the fine balance between clothing thermal and evaporative resistance, outer material emissivity, moisture quantity and location in clothing and applied radiation level, a different setup could lead to different results.

Prenatal diagnosis of a case with complete and uniform tetrasomy 12p by the utility of noninvasive prenatal testing

PURPOSE

To report a rare type of Pallister-Killian syndrome (PKS) diagnosed prenatally by the utility of non-invasive prenatal testing (NIPT).

METHODS

NIPT was performed in the first trimester. Conventional karyotyping and chromosomal microarray analysis (CMA) were performed on the amniotic samples in the second trimester. Copy number variation sequencing (CNV-seq) was used for the validation of fetal skin and the placental tissue after pregnancy termination.

RESULTS

NIPT results showed increased signal from chromosome 12p. Subsequent prenatal diagnostic testing by karyotype revealed 47, XY, +i (12p), and CMA displayed four copies of 12p: 12p13.33-12p11.1(173786_34835641) × 4. The CNV-seq results of the fetal skin and the fetal side of placenta showed four copies of 12p13.33-p11 and an estimated chimeric duplication of 34.08 Mb (chimerism ratio: 10%) in 12 p13.33-p11, respectively. However, no abnormality was detected by CNV-seq at the maternal side of placenta.

CONCLUSIONS

Our findings suggest that a positive signal from chromosome 12p on NIPT should raise suspicion for PKS. With the wide application of NIPT, the true positive of incidental finding is expected to increase.

Health care worker knowledge and attitudes towards uniform laundering during the COVID-19 pandemic

Background

The COVID-19 pandemic raised concerns towards domestic laundering of healthcare worker (HCW) uniforms; this is common practice in countries such as the United Kingdom (UK) and United States. Previous research suggested 4-32% of nurses did not adhere to laundry policies, which could be an infection control risk. This study aimed to investigate the knowledge and attitudes of UK healthcare workers towards domestic laundering of uniforms during the COVID-19 pandemic.

Methods

Online and paper questionnaires were distributed to HCWs and nursing students who regularly wear uniforms. Differences in knowledge between HCWs were analyzed by Chi-squared tests and attitudes were examined using exploratory factor analysis.

Results

About 86% of participants (n = 1099 of 1277) laundered their uniforms domestically. Respondents were confident in laundering their uniforms appropriately (71%), however 17% failed to launder at the recommended temperature (60°C). Most participants (68%) would prefer their employer launder their uniforms, with mixed negative emotions towards domestic laundering. Limited provision of uniforms and changing and/or storage facilities were a barrier to following guidelines.

Conclusion

Most HCWs domestically launder their uniforms, despite a preference for professional laundering. One-fifth of HCWs deviated from the UK National Health Service uniform guidelines; onsite changing facilities were the most significant barrier towards adherence.

Assessing decontamination and laundering processes for the removal of polycyclic aromatic hydrocarbons and flame retardants from firefighting uniforms

Firefighter uniforms protect firefighters from exposure to potentially harmful chemicals including a range of semi-volatile organic compounds (SVOCs). Contaminated uniforms can become a secondary source of firefighters' exposure to these chemicals. There is inconsistency on the removal efficiency of SVOCs during the cleaning, laundering and field decontamination of firefighting uniforms. Therefore, this study aims to assess how effective decontamination and laundering processes are in reducing firefighter uniforms as a vector for transport and exposure to SVOCs. Firefighters who had attended a controlled house fire and simulated container burns had their uniforms sampled pre- and post-laundering. Clean station wear was laundered with contaminated uniforms and after a load of contaminated uniforms to assess inter and intra load contamination. Surface wipes were collected from uniforms across 12 fire stations, after they had returned from a laundering provider. Concentrations of 13 polycyclic aromatic hydrocarbons (PAHs), six organophosphate flame retardants (OPFRs) and seven polybrominated diphenyl ethers (PBDEs) were measured in the collected samples. The concentrations of ∑₁₃ PAHs in firefighters uniforms ranged between 0.063 and 43 μg g^-1, while concentration of ∑₆ OPFRs were between 0.061 and 90 μg g^-1 with ∑₇ PBDEs concentrations being measured between 0.00054 and 0.97 μg g^-1.The highest concentrations of ∑₁₃ PAHs were measured on the outer layers of gloves at an average of 19 μg g^-1, with the highest ∑₆ OPFRs concentrations being measured in the middle layers of gloves at an average of 31 μg g^-1. The highest ∑₇ PBDEs concentrations were measured on the shell layers of turnout jackets at 0.42 μg g^-1. The significant reduction in ∑₁₃ PAHs after laundering or decontamination was only found in 3 of the 16 sampled areas from firefighting uniforms. No significant differences were found in the between pre- and post-laundering concentrations of ∑₆ OPFRs or ∑₇ PBDEs in firefighting uniforms. The current laundering techniques do not appear to effectively remove PAHs, OPFRs and PBDEs at the measured concentrations from firefighters' uniforms. Further research is required to assess if chemical exposure though firefighting uniforms poses a health risk to firefighters and to develop methods for the removal of SVOCs from firefighting uniforms.

The impact of school uniforms on primary school student's physical activity at school: outcomes of a cluster randomized controlled trial

Background

Many school-based physical activity (PA) interventions are complex and have modest effects when delivered in real world contexts. A commonly reported barrier to students’ PA, particularly among girls, are uniforms that are impractical (e.g. tunic/dress and black leather shoes). Modifying student uniforms may represent a simple intervention to enhance student PA. The primary aim of this trial was to assess the impact of a PA enabling uniform intervention (shorts, polo shirt and sports shoes) on girls’ moderate-to-vigorous physical activity (MVPA) and total PA i.e. counts per minute (cpm).

Methods

A cluster randomized controlled trial was undertaken in 42 primary schools in New South Wales, Australia. Schools were randomized on one school day to the intervention group, where students wore a PA enabling uniform (their sports uniform) or a control group, where students wore their usual traditional uniform. Student PA was measured using wrist-worn Actigraph GT3X and GT9X accelerometers. Linear mixed models controlling for student characteristics were used to examine the effects of the intervention..

Results

Of the 3351 eligible students, 2315 (69.1%) had parental consent and 2180 of these consenting students participated (94.2%) of which 1847 (84.7%) were included in the analysis. For the primary aim the study found no significant differences between girls at schools allocated to the intervention relative to the control on change in MVPA (0.76 min, 95% CI − 0.47 to 1.99, p = 0.22) or cpm (36.99, 95% CI − 13.88 to 87.86, p = 0.15). Exploratory analysis revealed small effects for a number of findings, including significant reduction in sedentary activity (− 1.77, 95% CI − 3.40 to − 0.14, p = 0.035) among all students at schools allocated to the intervention, and non-significant improvements in girls’ light intensity PA (1.47 min, 95% CI − 0.06 to 3.00, p = 0.059) and sedentary activity (− 2.23 min; 95% CI − 4.49 to 0.02, p = 0.052).

Conclusion

The findings suggests that the intervention may yield small improvements in some measure of PA and require substantiation in a larger RCT with longer-term follow-up. The inclusion of additional intervention components may be required to achieve more meaningful effects.

Trial registration

The trial was prospectively registered with Australian New Zealand Clinical Trials Register ACTRN12617001266358 1st September 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01084-0.

Effect of attire on client perceptions of veterinarians

This study examined the effect that veterinarian attire and gender had on clients' perceptions of veterinarians in a large academic specialty hospital. Clients volunteered to answer a survey in the small animal waiting area over a 3-month period. The survey consisted of demographic information, information about the nature of their appointment with their pet, and questions regarding clients' levels of comfort with and the perceived trustworthiness of a Caucasian male and Caucasian female model in four different types of attire: surgical scrubs, surgical scrubs with white lab coat, business casual, and business casual with white lab coat. Relevant effects of interest were estimated using linear mixed models. Five hundred and five clients participated in the survey, yielding a total of 6217 completed survey questions. Clients perceived veterinarians wearing white lab coats as more competent and reported more comfort with those veterinarians (P < 0.0001). When comparing surgical scrubs with no white lab coat to business attire with no white lab coat, surgical scrubs resulted in higher perceived competence and comfort levels (P < 0.0001). Wearing a white lab coat over both surgical scrubs and business casual increased clients' perceived competency and comfort levels compared to not wearing a white lab coat.

An Improved Method for Preparation of Uniform and Functional Mitochondria from Fresh Liver

Background and Aims: As the major energy source for mammalian cells, mitochondria have been the subject of numerous studies. However, the isolation and purification of healthy mitochondria, especially from fresh tissue, remains challenging. The most popular methods and kits involve various centrifugation steps which require substantial time and equipment but do not consistently provide pure preparations of functional mitochondria. The aim of this study was to determine whether methods could be devised to improve the purity and yield of functional mitochondria from fresh tissue. Methods: Fresh mouse liver was homogenized, and cells lysed. Particle size analysis, quantitation of mitochondrial DNA, mitochondrial oxygen consumption, and purity of mitochondria (by electron microscopy) were measured in samples after various purification steps and significant differences determined. Results: A two-step procedure consisting of centrifugation followed by filtration through 1.2μ and 0.8μ filters resulted in uniform mitochondrial preparations with diameters between 520-540 nm, and approximately 5-times more pure samples. The mitochondria thus obtained had oxygen consumption and sensitivities to mitochondrial inhibitors that were indistinguishable from those purified by centrifugation alone. Electron microscopy confirmed the presence of more uniform and 4-5 times greater concentrations of mitochondria compared to centrifugation alone. Conclusions: A two-step procedure consisting of sequential centrifugation followed by filtration is a rapid method for the production of highly purified, uniform and functional mitochondria.