Generation of renal Epo-producing cell lines by conditional gene tagging reveals rapid HIF-2 driven Epo kinetics,cell autonomous feedback regulation,and a telocyte phenotype

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Preprocedural Ultrasound for Infant Lumbar Puncture: A Randomized Clinical Trial

Background

Our purpose was to determine the potential effect of preprocedural ultrasound (US) to increase lumbar puncture (LP) success compared with standard palpation method. Further, we assessed feasibility of and clinician satisfaction with a standardized US protocol.

Methods

This prospective, two‐arm, parallel‐group randomized trial was conducted in a single‐center pediatric emergency department. We compared preprocedural US versus palpation method on success with infant LPs. Infants less than 3 months of age requiring LP were enrolled. Sixteen pediatric emergency medicine physicians with varied US experience were trained to conduct the USs to mark interspace locations. Primary outcome was successful LP, defined as obtaining a cerebrospinal fluid (CSF) sample on first attempt with < 1,000 red blood cells per high‐powered field (clear CSF). Secondary outcomes included clear CSF on any attempt, any CSF on the first attempt, traumatic LP proportion, and LP attempt frequency. Feasibility was assessed by comparing provider number attempting the LP and procedure duration. Clinician satisfaction and sonographer perceptions of US acceptability and impact were assessed.

Results

Eighty‐one patients consented and 80 were analyzed (99%): 40 per group. No statistical difference was seen for the primary outcome (p > 0.05) between intervention and control groups (difference 3%; 95% confidence interval = –19% to 24%). There were no statistical differences between intervention and controls groups for secondary outcomes including the rate of traumatic LPs, number of attempts, and the duration of LP procedure. Most sonographers (84%) strongly agreed or agreed that the US protocol was technically easy to perform, well tolerated by the patient (94%), well accepted by the family (100%), and well accepted by the LP procedural clinicians (99%). In the US group, the majority of clinicians who performed the LPs (68.4%) noted that the preprocedural US influenced their behavior, most commonly helping with overall visualization at the selected interspace (28.9%) or prompting a change in interspace (26.3% higher, 5.3% lower). Seventy‐seven percent agreed or strongly agreed that they would like to use the technique again for their next LP. The mean US duration was 4.6 minutes.

Conclusions

Preprocedural US by did not improve the rates of first‐attempt success when compared with palpation method. Our results suggest that US is feasible and well accepted, with a perceptible impact on care.

     

Analysis of L-leucine amino acid transporter species activity and gene expression by human blood brain barrier hCMEC/D3 model reveal potential LAT1, LAT4, B0AT2 and y+LAT1 functional cooperation

In the CNS, amino acid (AA) neurotransmitters and neurotransmitter precursors are subject to tight homeostatic control mediated by blood-brain barrier (BBB) solute carrier amino acid transporters (AATs). Since the BBB is composed of multiple closely apposed cell types and opportunities for human in vivo studies are limited, we used in vitro and computational approaches to investigate human BBB AAT activity and regulation. Quantitative real-time PCR (qPCR) of the human BBB endothelial cell model hCMEC/D3 (D3) was used to determine expression of selected AAT, tight junction (TJ), and signal transduction (ST) genes under various culture conditions. L-leucine uptake data were interrogated with a computational model developed by our group for calculating AAT activity in complex cell cultures. This approach is potentially applicable to in vitro cell culture drug studies where multiple “receptors” may mediate observed responses. Of 7 Leu AAT genes expressed by D3 only the activity of SLC7A5-SLC3A2/LAT1-4F2HC (LAT1), SLC43A2/LAT4 (LAT4) and sodium-dependent AATs, SLC6A15/B⁰AT2 (B⁰AT2), and SLC7A7/y⁺LAT1 (y⁺LAT1) were calculated to be required for Leu uptake. Therefore, D3 Leu transport may be mediated by a potentially physiologically relevant functional cooperation between the known BBB AAT, LAT1 and obligatory exchange (y⁺LAT1), facilitative diffusion (LAT4), and sodium symporter (B⁰AT2) transporters.     

Validation of an Acoustic Gastrointestinal Surveillance Biosensor for Postoperative Ileus

Background

Postoperative ileus (POI) can worsen outcomes, increase cost, and prolong hospitalization. An objective marker could help identify POI patients who should not be prematurely fed. We developed a disposable, non-invasive acoustic gastro-intestinal surveillance (AGIS) biosensor. We tested whether AGIS can distinguish healthy controls from patients recovering from abdominal surgery.

Study Design

AGIS is a disposable plastic device embedded with a microphone that adheres to the abdominal wall and connects to a computer that measures acoustic event rates. We compared intestinal rates of healthy subjects using AGIS for 60 min after a standardized meal to recordings of two postoperative groups: (1) patients tolerating standardized feeding and (2) POI patients. We compared intestinal rates among groups using ANOVA and t tests.

Results

There were 8 healthy controls, 7 patients tolerating feeding, and 25 with POI; mean intestinal rates were 0.14, 0.03, and 0.016 events per second, respectively (ANOVA p?p?=?0.017).

Conclusion

Non-invasive, abdominal acoustic monitoring distinguishes POI from non-POI subjects. Future research will test whether AGIS can identify patients at risk for development of POI and assist with postoperative feeding decisions.