CRISPR Activation in Mouse Trophoblast Stem Cells

The placenta is a vital organ that regulates nutrient supply to the developing embryo during gestation. In mice, the placenta is composed of trophoblast lineage and mesodermal derivatives, which merge through the chorioallantoic fusion process in a critical event for the progression of placenta development. The trophoblast lineage is derived from self-renewing, multipotent cells known as mouse trophoblast stem cells (mTSCs). These cells are a valuable tool that allows scientists to comprehend the signals regulating major placental cell types' self-renewal and differentiation capacity. Recent advances in CRISPR-Cas9 genome editing applied in mTSCs have provided novel insights into the molecular networks involved in placentation. Here, we present a comprehensive CRISPR activation (CRISPRa) protocol based on the CRISPR/gRNA-directed synergistic activation mediator (SAM) method to overexpress specific target genes in mTSCs.

Spirometry and respiratory oscillometry: Feasibility and concordance in schoolchildren with asthma

OBJECTIVE

The purpose of this study was to describe the feasibility of respiratory oscillometry (RO) in schoolchildren with asthma, and the concordance of its results with those of spirometry, to determine its clinical usefulness.

METHODS

RO and spirometry were performed in 154 children (6 to 14-year-old) with asthma, following strict quality criteria for the tests. Their feasibility (probability of valid test, time of execution, number of maneuvers needed to achieve a valid test, and perceived difficulty) was compared. The factors that influence feasibility were analyzed with multivariate methods. FEV1, FEV1/FVC, FVC and FEF25-75 for spirometry, and R5, AX and R5-19 for RO, were converted into z-scores and their concordance was investigated through intraclass correlation coefficients (ICC) and kappa indices for normal/abnormal values.

RESULTS

There were no differences in the probability of obtaining a valid RO or spirometry (83.1% vs. 81.8%, p = 0.868). RO required a lower number of maneuvers [mean (SD) 4.2 (1.8) versus 6.0 (1.6), p < 0.001] and less execution time [5.1 (2.7) versus 7.6 (2.4) minutes, p < 0.001], and patients considered it less difficult. Age increased the probability of obtaining valid RO and spirometry. The concordance of results between RO and spirometry was low, and only between zFEV1 and zAX could it be considered moderate (ICC = 0.412, kappa = 0.427).

CONCLUSION

RO and spirometry are feasible in children with asthma. RO has some practical advantages, but the concordance of its results with spirometry is low.

May cannabinoids prevent the development of chemotherapy-induced diarrhea and intestinal mucositis? Experimental study in the rat

BACKGROUND

The antineoplastic drug 5-fluoruracil (5-FU) is a pirimidine analog, which frequently induces potentially fatal diarrhea and mucositis. Cannabinoids reduce gastrointestinal motility and secretion and might prevent 5-FU-induced gut adverse effects. Here, we asked whether cannabinoids may prevent diarrhea and mucositis induced by 5-FU in the rat.

METHODS

Male Wistar rats received vehicle or the non-selective cannabinoid agonist WIN 55,212-2 (WIN; 0.5 mg kg^-1 injection^-1 , 1 injection day^-1 , 4 consecutive days) by intraperitoneal (ip) route; on the first 2 days, animals received also saline or 5-FU (150 mg kg^-1 injection^-1 , cumulative dose of 300 mg kg^-1 ). Gastrointestinal motor function was radiographically studied after barium contrast intragastric administration on experimental days 1 and 4. Structural alterations of the stomach, small intestine and colon were histologically studied on day 4. PAS staining and immunohistochemistry for Ki67, chromogranin A and CD163 were used to detect secretory, proliferating, and endocrine cells, and activated macrophages respectively.

KEY RESULTS

As shown radiographically, 5-FU induced significant gastric emptying delay (on days 1 and 4) and diarrhea (on day 4). WIN did not significantly alter the motility curves obtained for either control or 5-FU-treated animals but tended to reduce the severity of 5-FU-induced diarrhea and increased permanence of barium from day 1 to the beginning of day 4 in 5-FU-treated animals. 5-FU-induced mucositis was severe and not counteracted by WIN.

CONCLUSIONS AND INFERENCES

5-FU-induced diarrhea, but not mucositis, was partly prevented by WIN at a low dose. Cannabinoids might be useful to prevent chemotherapy-induced diarrhea.

X-ray analysis of gastrointestinal motility in conscious mice. Effects of morphine and comparison with rats

BACKGROUND

Non-invasive methods to study gastrointestinal (GI) motility are of high interest, particularly in chronic studies. Amongst these, radiographic techniques after contrast intragastric administration may offer many advantages. In previous studies, we have successfully and reproducibly applied these techniques together with a semiquantitative analysis method to characterize the effect of different drugs, acutely or repeatedly administered in rat models, but we have never before used these techniques in mice. These are very convenient in basic research. Our aim was to determine if our method is also valid in mice. Additionally, we determined the effect of morphine on GI motor function in both species.

METHODS

Animals received an intraperitoneal administration of morphine (at 10 and 5 mg/kg for rats and mice, respectively). Twenty min later, barium contrast (at 2 g/mL) was gavaged (2.5 and 0.4 mL for rats and mice respectively) and serial X-rays were obtained 0-8 h after contrast. X-rays were analyzed as previously described, using a semiquantitative score to build motility curves for each GI region.

KEY RESULTS

Motility was much faster in mice than in rats for all GI regions. Morphine at the doses used significantly depressed motility in both species to a similar extent if the whole gut or the upper GI regions (stomach, small intestine) were considered, although its effect seemed to be more intense in the lower GI regions (caecum, colorectum) in rats than in mice.

CONCLUSIONS & INFERENCES

We have validated our X-rays method for its use in mice.

Anti-asthmatic prescription variability in children according to age

INTRODUCTION

There is little research in the Spanish paediatric population about the consumption of anti-asthmatic agents. The aim of this study was to describe the current pattern of anti-asthmatic drug prescription in the paediatric population from a region of Spain, using the prescribed daily dose as a unit of measurement.

METHODS

We analysed the requirements of R03 therapeutic subgroup (anti-asthmatic agents) in children less than 14 years of age in the Public Health System of Castilla y León from 2005 to 2010. Consumption data are presented in prescribed daily doses per thousand inhabitants per day (PDHD) and compared with defined daily doses per thousand inhabitants per day (DHD).

RESULTS

394 876 prescriptions of anti-asthmatics were given to a population of 1 580 229 persons/year. Bronchodilators, leukotriene receptor antagonists, single inhaled corticosteroids (ICS) and long-acting β2-adrenergics associated with inhaled corticosteroids were the most commonly prescribed drugs: 7.5, 5.2, 4.9 and 2.2 PDHD, respectively. The maximum prescription of bronchodilators (15.9 PDHD/9.8 DHD) occurred in children under 12 months, with montelukast (8.9 PDHD/3.6 DHD) and single inhaled corticosteroids (7.9 PDHD/2.9 DHD) at one year of age.

CONCLUSIONS

Between 2005 and 2010, children under four years received a high prescription of anti-asthmatic drugs. The use of maintenance therapy was poorly aligned with the recommendations of asthma guidelines. The PDHD was more accurate for measuring consumption than DHD, especially in younger children.

Effect of infused norepinephrine dosage on pressure ulcers in perianesthesia care unit patients: a pilot study

To determine whether treatment with moderate-high dose norepinephrine is a contributory cause increasing the risk of pressure ulcer development in critical postoperative, mechanically ventilated, hyperglycemic patients. A pilot clinical cohort study was conducted in a PACU in a tertiary hospital. A convenience sample of 16 hyperglycemic patients undergoing mechanical ventilation with at least 24 hours' stay in the PACU were divided into two groups of eight according to dosage of norepinephrine infusion at any moment during the days monitored. One group received ≥ 2.5 mg/hour, and the other received <2.5 mg/hour. The dose of norepinephrine administered by continuous venous infusion and the occurrence of stage II pressure ulcers were recorded. The proportion of patients with pressure ulcers in the group receiving moderate-high dose of norepinephrine was 50% compared with 0% in the low-dose group (P = .038). The odds ratio for daily average norepinephrine administered (mg/hour) was 2.21 (95% CI = 1.27 to +infinite); exact P = .0049. The odds ratio for daily average norepinephrine administered adjusting for weight (mg/kg/hour) was 3.05 (95% CI = 1.299 to +infinite); exact P = .0016. Moderate-high dose norepinephrine is a contributory cause that significantly increases the risk of pressure ulcer development in certain short-stay PACU patients.

Precipitation of struvite in urine medium by urease-positive and urease-negative Yersinia strains

Yersinia strains either urease-positive or urease-negative were examined for precipitation of struvite in human urine at 25 and 37 degrees C. All urease-positive strains and 8 out of 10 urease-negative strains showed the ability to produce these crystals. Incubation time required for precipitation was longer for urease-negative strains and quantity of struvite formed was higher in urease-positive ones. Regarding incubation temperature, no significant influence has been observed.