A Rotated and Laterally Displaced Patellar Dislocation.

BACKGROUND: Patellar dislocations are a common orthopedic emergency with several variants. The rarer variants include rotational dislocations. These often require open reduction in the operating room. CASE REPORT: We report on a case of a combined rotational and lateral patellar dislocation in a young female. We suspected and made the diagnosis of a rotational dislocation after initial unsuccessful attempts at reduction under sedation. With the assistance of our orthopedic colleagues, we were able to perform a reduction of this patient's patella under sedation in the emergency department. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Awareness of uncommon patellar dislocations is an important area of knowledge for the emergency physician. A thorough understanding of indications and contraindications to closed reduction is important for efficient and safe management and disposition. Collaboration with orthopedic surgery colleagues is another important step in the evaluation of these patients.

Simultaneous Mapping of T1 and T2 Using Cardiac Magnetic Resonance Fingerprinting in a Cohort of Healthy Subjects at 1.5T.

BACKGROUND: Cardiac MR fingerprinting (cMRF) is a novel technique for simultaneous T1 and T2 mapping. PURPOSE: To compare T1 /T2 measurements, repeatability, and map quality between cMRF and standard mapping techniques in healthy subjects. STUDY TYPE: Prospective. POPULATION: In all, 58 subjects (ages 18-60). FIELD STRENGTH/SEQUENCE: cMRF, modified Look-Locker inversion recovery (MOLLI), and T2 -prepared balanced steady-state free precession (bSSFP) at 1.5T. ASSESSMENT: T1 /T2 values were measured in 16 myocardial segments at apical, medial, and basal slice positions. Test-retest and intrareader repeatability were assessed for the medial slice. cMRF and conventional mapping sequences were compared using ordinal and two alternative forced choice (2AFC) ratings. STATISTICAL TESTS: Paired t-tests, Bland-Altman analyses, intraclass correlation coefficient (ICC), linear regression, one-way analysis of variance (ANOVA), and binomial tests. RESULTS: Average T1 measurements were: basal 1007.4±96.5 msec (cMRF), 990.0±45.3 msec (MOLLI); medial 995.0±101.7 msec (cMRF), 995.6±59.7 msec (MOLLI); apical 1006.6±111.2 msec (cMRF); and 981.6±87.6 msec (MOLLI). Average T2 measurements were: basal 40.9±7.0 msec (cMRF), 46.1±3.5 msec (bSSFP); medial 41.0±6.4 msec (cMRF), 47.4±4.1 msec (bSSFP); apical 43.5±6.7 msec (cMRF), 48.0±4.0 msec (bSSFP). A statistically significant bias (cMRF T1 larger than MOLLI T1 ) was observed in basal (17.4 msec) and apical (25.0 msec) slices. For T2 , a statistically significant bias (cMRF lower than bSSFP) was observed for basal (-5.2 msec), medial (-6.3 msec), and apical (-4.5 msec) slices. Precision was lower for cMRF-the average of the standard deviation measured within each slice was 102 msec for cMRF vs. 61 msec for MOLLI T1 , and 6.4 msec for cMRF vs. 4.0 msec for bSSFP T2 . cMRF and conventional techniques had similar test-retest repeatability as quantified by ICC (0.87 cMRF vs. 0.84 MOLLI for T1 ; 0.85 cMRF vs. 0.85 bSSFP for T2 ). In the ordinal image quality comparison, cMRF maps scored higher than conventional sequences for both T1 (all five features) and T2 (four features). DATA CONCLUSION: This work reports on myocardial T1 /T2 measurements in healthy subjects using cMRF and standard mapping sequences. cMRF had slightly lower precision, similar test-retest and intrareader repeatability, and higher scores for map quality. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1 J. Magn. Reson. Imaging 2020;52:1044-1052.

Evidence for using PRN pharmacotherapy to treat undifferentiated acute agitation or aggression.

BACKGROUND: This systematic review identified published studies that evaluated the use of pro re nata (PRN) medication in patients with acute agitation or aggression of undifferentiated etiology. METHODS: A literature search was conducted of PubMed and MEDLINE for randomized controlled trials (RCTs) that evaluated the use of PRN medications for individuals with undifferentiated agitation or aggression. Bibliographic databases of published articles were also searched for additional studies. RESULTS: A total of 15 studies were identified that assessed the effects of first-generation antipsychotics (FGAs), second-generation antipsychotics (SGAs), benzodiazepines, and combination therapies. All RCTs showed variable degrees of sedation and decreased agitation over time with the use of these medications, as well as variable levels of adverse events. CONCLUSIONS: Evidence exists to support the use of specific SGAs as firstline PRN medications in the management of acutely agitated individuals. While evidence exists to support the use of FGAs, benzodiazepines, and combination therapy, efficacy is similar for each class, and SGAs appear to have the most favorable adverse effect profile.

Thermoresponsive nanofabricated substratum for the engineering of three-dimensional tissues with layer-by-layer architectural control.

Current tissue engineering methods lack the ability to properly recreate scaffold-free, cell-dense tissues with physiological structures. Recent studies have shown that the use of nanoscale cues allows for precise control over large-area 2D tissue structures without restricting cell growth or cell density. In this study, we developed a simple and versatile platform combining a thermoresponsive nanofabricated substratum (TNFS) incorporating nanotopographical cues and the gel casting method for the fabrication of scaffold-free 3D tissues. Our TNFS allows for the structural control of aligned cell monolayers which can be spontaneously detached via a change in culture temperature. Utilizing our gel casting method, viable, aligned cell sheets can be transferred without loss of anisotropy or stacked with control over individual layer orientations. Transferred cell sheets and individual cell layers within multilayered tissues robustly retain structural anisotropy, allowing for the fabrication of scaffold-free, 3D tissues with hierarchical control of overall tissue structure.

Arsenic exposure disrupts neurite growth and complexity in vitro.

Arsenic has neurotoxic effects on both central and peripheral components of the mature nervous system. There is increasing evidence that exposure to arsenic is also toxic to the developing nervous system and can result in decreased cell division and increased apoptosis in cultured developing neurons. However, the effects of arsenic on subsequent neuron growth and morphology remain unclear. In the present study we used differentiating PC12 cells to investigate the effects of sodium arsenite on the early stages of neurite production and growth. We find that arsenic has concentration- and time-dependent effects on initial neurite outgrowth in vitro. Exposure to low micromolar levels of sodium arsenite for five days results in reduced neurite production, outgrowth and complexity in newly differentiating PC12 cells. Furthermore, we find that exposure of more mature PC12 cells to arsenite can inhibit further neurite development. These results suggest that exposure to arsenic can disrupt early stages of neuron differentiation by altering the normal progression of morphological development and could potentially contribute to compromised long term functioning of neurons.