Medically ready for discharge: A multisite "point-in-time" assessment of hospitalized patients

BACKGROUND

Time spent awaiting discharge after the acute need for hospitalization has resolved is an important potential contributor to hospital length of stay (LOS).

OBJECTIVE

To measure the prevalence, impact, and context of patients who remain hospitalized for prolonged periods after completion of acute care needs.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a cross-sectional "point-in-time" survey at each of 15 academic US hospitals using a structured data collection tool with on-service acute care medicine attending physicians in fall 2022.

MAIN OUTCOMES AND MEASURES

Primary outcomes were number and percentage of patients considered "medically ready for discharge" with emphasis on those who had experienced a "major barrier to discharge" (medically ready for discharge for ≥1 week). Estimated LOS attributable to major discharge barriers, contributory discharge needs, and associated hospital characteristics were measured.

RESULTS

Of 1928 patients sampled, 35.0% (n = 674) were medically ready for discharge including 9.8% (n = 189) with major discharge barriers. Many patients with major discharge barriers (44.4%; 84/189) had spent a month or longer medically ready for discharge and commonly (84.1%; 159/189) required some form of skilled therapy or daily living support services for discharge. Higher proportions of patients experiencing major discharge barriers were found in public versus private, nonprofit hospitals (12.0% vs. 7.2%; p = .001) and county versus noncounty hospitals (14.5% vs. 8.8%; p = .002).

CONCLUSIONS

Patients experience major discharge barriers in many US hospitals and spend prolonged time awaiting discharge, often for support needs that may be outside of clinician control.

Sample size effects for Lévy flight of photons in atomic vapors

Lévy flight superdiffusion consists of random walks characterized by very long jumps that dominate the transport. However, the finite size of real samples introduces truncation of long jumps and modifies the transport properties. We measure typical Levy flight parameters for photon diffusion in atomic vapor characterized by a Voigt absorption profile. We observe the change of Lévy parameter as a function of truncation length. We associate this variation with size-dependent contributions from different spectral regions of the emission profile with the Doppler core dominating the transport for thin samples and Lorentz wings for thick samples. Monte Carlo simulations are implemented to support the interpretation of results.

Self-amplifying memory based on multiple cascading four-wave mixing via recoil-induced resonance

We report on a new, to the best of our knowledge, type of optical memory that allows for the amplification of the optical signal carrying the stored information during its reading process. The memory mechanism is demonstrated in an ensemble of cold cesium atoms and is based on the multiple parametric four-wave mixing exploring the external atomic degrees of freedom via recoil-induced resonances. We have particularly demonstrated the storage of light carrying orbital angular momentum with a fourfold amplifying factor for the retrieved signal during the reading process. Memory lifetimes of the order of hundreds of microseconds have been measured, and possible applications for this self-amplifying memory are discussed.

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10^{21} Protons on Target

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3}  eV^{2}/c^{4}.

Rare susceptibility variants for bipolar disorder suggest a role for G protein-coupled receptors

Bipolar disorder (BD) is a prevalent mood disorder that tends to cluster in families. Despite high heritability estimates, few genetic susceptibility factors have been identified over decades of genetic research. One possible interpretation for the shortcomings of previous studies to detect causative genes is that BD is caused by highly penetrant rare variants in many genes. We explored this hypothesis by sequencing the exomes of affected individuals from 40 well-characterized multiplex families. We identified rare variants segregating with affected status in many interesting genes, and found an enrichment of deleterious variants in G protein-coupled receptor (GPCR) family genes, which are important drug targets. Furthermore, we showed targeted downstream GPCR dysregulation for some of the variants that may contribute to disease pathology. Particularly interesting was the finding of a rare and functionally relevant nonsense mutation in the corticotropin-releasing hormone receptor 2 (CRHR2) gene that tracked with affected status in one family. By focusing on rare variants in informative families, we identified key biochemical pathways likely implicated in this complex disorder.

Optical memory based on quantized atomic center-of-mass motion

We report a new type of optical memory using a pure two-level system of cesium atoms cooled by the magnetically assisted Sisyphus effect. The optical information of a probe field is stored in the coherence between quantized vibrational levels of the atoms in the potential wells of a 1-D optical lattice. The retrieved pulse shows Rabi oscillations with a frequency determined by the reading beam intensity and are qualitatively understood in terms of a simple theoretical model. The exploration of the external degrees of freedom of an atom may add another capability in the design of quantum-information protocols using light.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135  μ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66  μ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

Measurement of Coherent π^{+} Production in Low Energy Neutrino-Carbon Scattering

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K.

A molecular model for neurodevelopmental disorders

Genes implicated in neurodevelopmental disorders (NDDs) important in cognition and behavior may have convergent function and several cellular pathways have been implicated, including protein translational control, chromatin modification, and synapse assembly and maintenance. Here, we test the convergent effects of methyl-CpG binding domain 5 (MBD5) and special AT-rich binding protein 2 (SATB2) reduced dosage in human neural stem cells (NSCs), two genes implicated in 2q23.1 and 2q33.1 deletion syndromes, respectively, to develop a generalized model for NDDs. We used short hairpin RNA stably incorporated into healthy neural stem cells to supress MBD5 and SATB2 expression, and massively parallel RNA sequencing, DNA methylation sequencing and microRNA arrays to test the hypothesis that a primary etiology of NDDs is the disruption of the balance of NSC proliferation and differentiation. We show that reduced dosage of either gene leads to significant overlap of gene-expression patterns, microRNA patterns and DNA methylation states with control NSCs in a differentiating state, suggesting that a unifying feature of 2q23.1 and 2q33.1 deletion syndrome may be a lack of regulation between proliferation and differentiation in NSCs, as we observed previously for TCF4 and EHMT1 suppression following a similar experimental paradigm. We propose a model of NDDs whereby the balance of NSC proliferation and differentiation is affected, but where the molecules that drive this effect are largely specific to disease-causing genetic variation. NDDs are diverse, complex and unique, but the optimal balance of factors that determine when and where neural stem cells differentiate may be a major feature underlying the diverse phenotypic spectrum of NDDs.

MicroRNA regulation of central glial cell line-derived neurotrophic factor (GDNF) signalling in depression

Although multiple studies have reported that peripheral glial cell line-derived neurotrophic factor (GDNF) is reduced in depression, cerebral GDNF signalling has yet to be examined in this condition. Here, we report an isoform-specific decrease in GDNF family receptor alpha 1 (GFRA1) mRNA expression, resulting in lowered GFRα1a protein levels in basolateral amygdala (BLA) samples from depressed subjects. Downregulation of GFRα1a was associated with increased expression of microRNAs, including miR-511, predicted to bind to long 3' untranslated region (3'-UTR)-containing transcripts (GFRA1-L) coding for GFRα1a. Transfection of human neural progenitor cells (NPCs) with a miR-511 mimic was sufficient to repress GFRA1-L/GFRα1a without altering GFRα1b, and resulted in pathway-specific changes in immediate early gene activity. Unexpectedly, GFRα1a knockdown did not reduce NPC responses to GDNF. Rather, it greatly enhanced mitogen-activated protein kinase signalling. This effect appeared to be mediated by GDNF/soluble GFRα1/neural cell adhesion molecule binding, and substituting the soluble GFRα1a/GFRα1b content of miR-511-transfected NPCs with that of controls rescued signalling. In light of previous reports suggesting that GFRα1b can inhibit GFRα1a-induced neuroplasticity, we also assessed the association between GFRα1 and doublecortin (DCX; a hyperplastic marker) in human BLA. Although controls displayed coordinated expression of GFRα1a and b isoforms and these correlated positively with DCX, the only significant association observed among depressed subjects was a strongly negative correlation between GFRα1b and DCX. Taken together, these results suggest that microRNA-mediated reductions of GFRα1a in depression change the quality, rather than the quantity, of GDNF signalling. They also suggest that central GDNF signalling may represent a novel target for antidepressant treatment.

Idelalisib for the treatment of indolent non-Hodgkin's lymphoma

Idelalisib is a novel, highly selective, small-molecule, tyrosine kinase inhibitor with potent activity against phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta isoform (PI3Kδ). Given the highly selective inhibition of this compound, studies have shown that idelalisib is able to achieve significantly increased apoptotic activity in B-cell acute lymphoblastic leukemia (B-ALL) and chronic lymphocytic leukemia (CLL) cell lines, without significant increase in apoptosis among normal T and natural killer cells. Recent studies have suggested potential clinical benefit with idelalisib as either a single agent or in combination with established chemotherapeutic compounds including bendamustine and rituximab in relapsed/refractory CLL. This review will focus on the preclinical pharmacology, pharmacokinetics and clinical utility of idelalisib in the treatment of various indolent forms of non-Hodgkin's lymphoma.

Double-blind randomized evaluation of clinical and biological tolerance of polyethylene glycol 4000 versus lactulose in constipated children

OBJECTIVES

To assess the safety of a polyethylene glycol (PEG) 4000 laxative without additional salts in pediatric patients.

STUDY DESIGN

This was a 3-month multicenter, randomized, double-blind, double-dummy, lactulose-controlled, parallel study enrolling 96 ambulatory constipated children aged 6 months to 3 years, treated daily with 4-8 g PEG or 3.33 g-6.66 g lactulose. Total protein, albumin, iron, electrolytes, and vitamins B9 (folates), A and D (25OHD3) were measured in blood before and after treatment (day 84) in a central laboratory.

RESULTS

The percentage of children with at least one value out of normal range at day 84 with respect to baseline status (with or without at least one value out of normal range), i.e. the primary endpoint, was 87% and 90% in the PEG and lactulose groups, respectively, without any difference between groups. The whole blood parameters showed no qualitative or quantitative treatment-related changes. Vitamin A values were above normal range in 56% and 41% of children at baseline versus 33% and 36% at day 84 in the PEG and lactulose groups, respectively. Iron values were similarly under normal range in 47% and 51% at baseline versus 42% and 51% at day 84. Clinical tolerance was similar for both treatments except for vomiting and flatulence, which were significantly higher with lactulose. Significantly higher improvements were evidenced with PEG regarding stool consistency, appetite, fecaloma and use of additional laxatives.

CONCLUSION

This 3-month study in 96 constipated children aged 6 months to 3 years confirms the long-term tolerance of PEG 4000 in pediatrics and indicates a PEG efficacy similar to or greater than that of lactulose.

The role of surfactant-associated protein A in pulmonary host defense

Resident alveolar macrophages play a key role in the initial defense against inhaled pathogens. Surface molecules bind opsonized as well as nonopsonized microbes and mediate their internalization by the macrophage. The recent discovery that specific C-type lectins can bind to the surface of a wide range of pathogens has led to the hypothesis that these lectins are involved in the initial phases of microbe recognition by the macrophage. Studies in our laboratory focus on the role of the lung-specific lectin surfactant associated protein A (SP-A) in host defense against pulmonary pathogens. SP-A contains a carbohdyrate recognition domain that appears to bind specifically to exposed carbohydrate residues on the surface of microorganisms. This lectin-microorganism interaction leads to entry of specific pathogens into macrophages and activation of intracellular pathways, resulting in the production of antimicrobial mediators such as nitric oxide. Many studies, including those involving SP-A-deficient mice, underscore the importance of this protein in pulmonary innate immunity. However, the intramacrophage mechanisms underlying the effects of SP-A are still unclear. This article describes our current knowledge of SP-A and its interactions with immune cells and pathogens with a focus on recent findings from our laboratory regarding SP-A interactions with mycobacteria.

Surfactant protein A enhances mycobacterial killing by rat macrophages through a nitric oxide-dependent pathway

Surfactant-associated protein A (SP-A) is involved in surfactant homeostasis and host defense in the lung. We have previously demonstrated that SP-A specifically binds to and enhances the ingestion of bacillus Calmette-Guerin (BCG) organisms by macrophages. In the current study, we investigated the effect of SP-A on the generation of inflammatory mediators induced by BCG and the subsequent fate of ingested BCG organisms. Rat macrophages were incubated with BCG in the presence and absence of SP-A. Noningested BCG organisms were removed, and the release of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide were measured at varying times. TNF-alpha and nitric oxide production induced by BCG were enhanced by SP-A. In addition, SP-A enhanced the BCG-induced increase in the level of inducible nitric oxide synthase protein. Addition of antibodies directed against SPR210, a specific macrophage SP-A receptor, inhibited the SP-A-enhanced mediator production. BCG in the absence of SP-A showed increased growth over a 5-day period, whereas inclusion of SP-A dramatically inhibited BCG growth. Inhibition of nitric oxide production blocked BCG killing in the presence and absence of SP-A. These results demonstrate that ingestion of SP-A-BCG complexes by rat macrophages leads to production of inflammatory mediators and increased mycobacterial killing.

Cholesterol biosynthesis in chicken liver: effect of triiodothyronine

The effect of a single injection of L-triiodothyronine (T3) on the levels of liver cholesterol and liver 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) has been studied in chicken. A minimal dose of 8 micrograms/animal produces its maximal effects after 12 h. T3 enhances both HMGR activity and cholesterol levels in liver. Both effects are suppressed when protein synthesis inhibitors (actinomycin D or cycloheximide) are administered along with the hormone. Solubilized and membrane-bound HMGR activities are equally influenced by the hormone. The in vitro addition of T3 does not affect the HMGR activity. It is concluded that T3 increases cholesterol biosynthesis in chicken liver through the activation of de novo protein synthesis.