Simulation and evaluation of the protective barrier enclosure for cardiopulmonary resuscitation

INTRODUCTION

The COVID-19 pandemic has presented a significant challenge for infection prevention and control during airway management in anaesthesia and critical care. The protective barrier enclosure has been described and studied particularly for perioperative anaesthesia use. The potential use of the protective barrier enclosure during cardiopulmonary resuscitation has been poorly explored in the current literature. This work aims to demonstrate the potential of protective barrier enclosure in limiting aerosol dispersion during cardiopulmonary resuscitation delivery.

METHODS

A proof-of-concept simulation study was conducted to evaluate the protective properties of the protective barrier enclosure during cardiopulmonary resuscitation. Aerosol was simulated using a fluorescent dye trapped within the manikin. Three different methods of cardiopulmonary resuscitation delivery with a protective barrier enclosure applied over the manikin's head were conducted. The first method simulated a chest compression only cardiopulmonary resuscitation, the second method also used chest compressions only, with a face mask fitted on the victim, while the third method, the victim was given chest compression and bag-valve-mask ventilation by two rescuers.

RESULTS

In the first method, release of aerosol from the manikin's mouth was observed during chest compression, while in second method, most of the aerosol was trapped within the face mask, with only minor leaking. However, when bag-valve-mask ventilation was delivered, the aerosol leaked out at high speed around the bag-valve-mask seal. No aerosol condensation was found outside of the protective barrier enclosure in all scenes.

CONCLUSION

Protective barrier enclosure may reduce aerosol exposure to the rescuers during out-of-hospital cardiac arrest.

Characteristics of viral pneumonia in non-HIV immunocompromised and immunocompetent patients: a retrospective cohort study

BACKGROUND

Concerning viral pneumonia, few large-scale comparative studies have been published describing non-HIV immunocompromised and immunocompetent patients, but the epidemiological characteristics of different viruses or underlying diseases in immunocompromised hosts are lacking.

METHODS

We retrospectively recruited patients hospitalised with viral pneumonia from six academic hospitals in China between August 2016 and December 2019. We measured the prevalence of comorbidities, coinfections, nosocomial infections, and in-hospital mortalities.

RESULTS

Of the 806 patients, 370 were immunocompromised and 436 were immunocompetent. The disease severity and in-hospital mortality of immunocompromised patients were higher than those of immunocompetent patients. During the influenza season, an increased number of cases of influenza virus (IFV) infection were found in the immunocompromised group, followed by cases of cytomegalovirus (CMV) and respiratory syncytial virus (RSV) infection. During the non-influenza season, CMV was the main virus detected in the immunocompromised group, while RSV, adenovirus (AdV), parainfluenza virus (PIV), and rhinovirus (HRV) were the main viruses detected in the immunocompetent group. Pneumonia caused by Pneumocystis jirovecii (22.4%), Aspergillus spp. (14.1%), and bacteria (13.8%) were the most frequently observed coinfections in immunocompromised patients but not in immunocompetent patients (Aspergillus spp. [10.8%], bacteria [7.1%], and Mycoplasma spp. [5.3%]). CMV infection and infection with two-or-more viruses were associated with a higher in-hospital mortality rate than non-IFV infection. However, patients with IFV and non-IFV infection in immunocompromised patients had similar disease severity and prognosis.

CONCLUSIONS

Immunocompromised patients have a high frequency of coinfections, and a higher mortality rate was observed among those infected with CMV and two-or-more viruses. In addition, patients with IFV and non-IFV infection in immunocompromised patients had similar same disease severity and prognosis. The type of viral infection varied with seasons.

New-Onset Seizures in Three COVID-19 Patients: A Case Series

SUMMARY

Neurological manifestations of coronavirus disease 2019 most commonly present in severe cases and range from mild complications, such as headache and dizziness, to severe complications, such as encephalopathy and acute cerebrovascular disease. Seizures, however, are an underreported neurological manifestation of this disease. We present three critically ill coronavirus disease 2019 patients with EEG monitoring who developed new-onset seizures and encephalopathy up to three-and-a-half weeks after symptom onset. There are several speculated etiologies for the development of new-onset seizures; however, the pathogenic mechanism remains unknown. Testing of coronavirus disease 2019 in the cerebrospinal fluid in addition to extensive research on neurological manifestations is warranted.

Aetiology and prognostic risk factors of mortality in patients with pneumonia receiving glucocorticoids alone or glucocorticoids and other immunosuppressants: a retrospective cohort study

OBJECTIVES

Long-term use of high-dose glucocorticoids can lead to severe immunosuppression and increased risk of treatment-resistant pneumonia and mortality. We investigated the aetiology and prognostic risk factors of mortality in hospitalised patients who developed pneumonia while receiving glucocorticoid therapy alone or glucocorticoid and other immunosuppressant therapies.

DESIGN

Retrospective cohort study.

SETTING

Six secondary and tertiary academic hospitals in China.

PARTICIPANTS

Patients receiving glucocorticoids who were hospitalised with pneumonia between 1 January 2013 and 31 December 2019.

MAIN OUTCOMES

We analysed the prevalence of comorbidities, microbiology, antibiotic susceptibility patterns, 30-day and 90-day mortality and prognostic risk factors.

RESULTS

CONCLUSIONS: A total of 716 patients were included, with pneumonia pathogens identified in 69.8% of patients. Significant morbidities occurred, including respiratory failure (50.8%), intensive care unit transfer (40.8%) and mechanical ventilation (36%), with a 90-day mortality of 26.0%. Diagnosis of pneumonia occurred within 6 months of glucocorticoid initiation for 69.7% of patients with Cytomegalovirus (CMV) pneumonia and 79.0% of patients with Pneumocystis jirovecii pneumonia (PCP). Pathogens, including Pneumocystis, CMV and multidrug-resistant bacteria, were identified more frequently in patients with persistent lymphocytopenia and high-dose glucocorticoid treatment (≥30 mg/day of prednisolone or equivalent within 30 days before admission). The 90-day mortality was significantly lower for non-CMV viral pneumonias than for PCP (p<0.05), with a similar mortality as CMV pneumonias (24.2% vs 38.1% vs 27.4%, respectively). Cox regression analysis indicated several independent negative predictors for mortality in this patient population, including septic shock, respiratory failure, persistent lymphocytopenia, interstitial lung disease and high-dose glucocorticoid use.Patients who developed pneumonia while receiving glucocorticoid therapy experienced high rates of opportunistic infections, with significant morbidity and mortality. These findings should be carefully considered when determining treatment strategies for this patient population.

Aerosol containment box to the rescue: extra protection for the front line

As the COVID-19 pandemic has created shortages of vital personal protective equipment that threatens healthcare workers’ risk of exposure, a need for innovative new ways to protect healthcare workers has emerged. An aerosol containment box that covers the patient’s head and neck in bed provides a solution to protect clinicians during aerosol-generating procedures such as intubation. We collaborated with original designer HYL and modified the size to adapt to larger patients and operator mobility. We expand its applicability by allowing the use of different instruments. The container is outfitted with an ultra-low particulate air-equipped filtration vacuum device to create negative pressure within the chamber and actively remove floating droplet nuclei generated during a procedure. This barrier method will be a valuable and economical option to protect healthcare workers on the front line globally during this pandemic and beyond.

A pilot survey of ventilated cancer patients' perspectives and recollections of early mobility in the intensive care unit

Purpose

To determine the level of recall, satisfaction, and perceived benefits of early mobility (EM) among ventilated cancer patients after extubation in the intensive care unit (ICU).

Methods

A survey of patients’ perceptions and recollections of EM was administered within 72 h of extubation. Data on recall of EM participation, activities achieved, adequacy of staffing and rest periods, strength to participate, activity level of difficulty, satisfaction with staff instructions, breathing management, and overall rating of the experience were analyzed. The Confusion Assessment Method for ICU (CAM-ICU) was used for delirium screening.

Results

Fifty-four patients comprised the study group. Nearly 90% reported satisfaction with instructions, staffing, rest periods, and breathing management during EM. Participants indicated that EM maintained their strength (67%) and gave them control over their recovery (61%); a minority felt optimistic (37%) and safe (22%). Patients who achieved more sessions and “out-of-bed” exercises had better recall of actual activities compared with those who exercised in bed. Overall, patients with CAM-ICU-positive results (33%) performed less physical and occupational therapy exercises.

Conclusions

Ventilated cancer patients reported an overall positive EM experience, but factual memory impairment of EM activities was common. These findings highlight the needs and the importance of shaping strategies to deliver a more patient focused EM experience.

Electronic supplementary material

The online version of this article (10.1007/s00520-019-04867-1) contains supplementary material, which is available to authorized users.

A Basic Therapy Gone Awry

Baking soda (sodium bicarbonate) is a common household item that has gained popularity as an alternative cancer treatment. Some have speculated that alkali therapy neutralizes the extracellular acidity of tumor cells that promotes metastases. Internet blogs have touted alkali as a safe and natural alternative to chemotherapy that targets cancer cells without systemic effects. Sodium bicarbonate overdose is uncommon, with few reports of toxic effects in humans. The case described here is the first reported case of severe metabolic alkalosis related to topical use of sodium bicarbonate as a treatment for cancer. This case highlights how a seemingly benign and readily available product can have potentially lethal consequences.

Bioanalytical system for detection of cancer cells with photoluminescent ZnO nanorods

Using photoluminescent ZnO nanorods and carbohydrate marker SSEA-4, a novel cancer cell recognition system was developed. Immobilization of SSEA-4 antibodies (αSSEA-4) on ZnO nanorods was performed in buffer solution (pH = 7.1) over 2 h. The cancer cell line probes were fixed on the glass slide. One hundred microliters of ZnO-αSSEA-4 conjugates were deposited on the cell probe and exposed for 30 min. After washing photoluminescence spectra were recorded. Based on the developed methodology, ZnO-αSSEA-4 probes were tested on patient-derived breast and colorectal carcinoma cells. Our data clearly show that the carbohydrate SSEA-4 molecule is expressed on cancer cell lines and patient-derived cancer cells. Moreover, SSEA-4 targeted ZnO nanorods bind to the patient-derived cancer cells with high selectivity and the photoluminescence signal increased tremendously compared to the signal from the control samples. Furthermore, the photoluminescence intensity increase correlated with the extent of malignancy in the target cell population. A novel portable bioanalytical system, based on optical ZnO nanorods and fiber optic detection system was developed. We propose that carbohydrate SSEA-4 specific ZnO nanorods could be used for the development of cancer diagnostic biosensors and for targeted therapy.

Auditory efferent dysfunction in normal-hearing chronic idiopathic tinnitus

OBJECTIVE

To investigate the function of the auditory efferent system in patients with chronic idiopathic tinnitus, but normal pure-tone audiograms.

METHODS

We studied 15 subjects with normal hearing that had experienced either unilateral or bilateral persistent tinnitus for at least 3 months. The ears of the 15 subjects were classified into tinnitus-positive-ear (TPE) and tinnitus-negative-ear (TNE) groups. The control-ear group (CE) comprised the ears of 15 subjects with normal hearing and no tinnitus. We measured different types of otoacoustic emissions (OAEs), including spontaneous (SOAEs), transient evoked (TEOAEs), and distortion product (DPOAEs). We also analyzed contralateral suppression of OAEs and auditory brainstem responses (ABRs). Data were compared among TPE, TNE, and CE groups.

RESULTS

The data associated with cochlear mechanics, including the prevalence of SOAEs, the number of SOAE peaks, and the overall TEOAE responses in the absence of a contralateral stimulus, were not significantly different among the TPE, TNE, and CE groups. In the TPE group, contralateral stimuli failed to significantly suppress overall TEOAEs, and contralateral suppression of DPOAEs was significantly reduced over a limited frequency range. Furthermore, the TPE group showed prolonged latencies in waves III and V of ABRs.

CONCLUSION

This study demonstrated that abnormal contralateral suppression of OAEs and ABRs indicated a dysfunction in the ipsilateral efferent medial olivocochlear system; this might play a role in normal-hearing tinnitus.

Transcatheter injection-induced changes in human bone marrow-derived mesenchymal stem cells

Human mesenchymal stem cells (hMSC) are being administered by direct intramyocardial (IM) injection into patients with myocardial dysfunction with an objective to improve clinical status. However, surprisingly little attention has been directed to qualifying hMSC functionality beyond simple viability. In particular, the transit of hMSCs through a small-caliber needle lumen, the final fluidic pathway for all IM injection devices, may be especially prone to inducing unwarranted effects on cell function. This study evaluated the changes in clonogenicity, gene expression, and cytokine secretion that may be induced in hMSC (20 million/ml) by injection through a 26-gauge Nitinol needle at two different flow rates compared to noninjected control samples. Results indicated that hMSC viability and colony forming unit (CFU) formation was not altered by changes in injection rate, although a trend toward lower titers was noted at the higher flow rate, for the specific batch of hMSCs studied. The gene expression and cytokine analysis data suggest that delivering a suspension of MSCs through narrow lumen needles may marginally alter certain gene expression programs, but that such in vitro effects are transient and not translated into measurable differences in protein production. Gene expression levels of four cytokines (bFGF, SDF-1, SCF, VEGF) were significantly different at 400 microl/min, and that of all cytokines were significantly different at 1600 microl/min when compared to controls (p < 0.05). These changes were less pronounced (statistically insignificant for most cases, p > 0.05) and, in certain instances directionally opposite, at 72 h. However, no differences in the amounts of secreted bFGF, VEGF, or TGF-beta were detectable at either of the two time points or flow rates. We infer that intramyocardial administration by transcatheter techniques is unlikely to interfere with the machinery required for cell replication or secretion of regulatory and other growth factors, which are the mainstays of MSC contribution to cardiac tissue repair and regeneration.

Broadband and omnidirectional antireflection employing disordered GaN nanopillars

Disordered GaN nanopillars of three different heights: 300, 550, and 720 nm are fabricated, and demonstrate broad angular and spectral antireflective characteristics, up to an incident angle of 60? and for the wavelength range of lambda=300-1800 nm. An algorithm based on a rigorous coupled-wave analysis (RCWA) method is developed to investigate the correlations between the reflective characteristics and the structural properties of the nanopillars. The broadband and omnidirectional antireflection arises mainly from the refractive-index gradient provided by nanopillars. Calculations show excellent agreement with the measured reflectivities for both s- and p- polarizations.

Hemangioblastic characteristics of fetal bone marrow-derived Flk1(+)CD31(-)CD34(-) cells

OBJECTIVE

To investigate whether Flk1(+)CD31(-)CD34(-) cells isolated from fetal bone marrow (BM) have characteristics of hemangioblasts, i.e., progenitors of endothelial and hematopoietic cells.

MATERIALS AND METHODS

Mononuclear cells from fetal BM were negatively sorted by CD45, GlyA, and CD34 micromagnetic beads, then cultured to form cell colonies. A single colony was harvested. Culture-expanded cells were seeded on ECM gel or semisolid media supplemented with endothelial and hematopoietic growth factors, respectively. Immunochemistry staining and RT-PCR were performed for cell characterization.

RESULTS

99% of cells from the single colony maintained Flk1(+) and CD31/CD34(-) during passaging. On ECM gel, Flk1(+)CD31(-)CD34(-) cells could grow into vascular structure that was positive for CD31 and vWF. There were round CD34(+) cells around the vascular structure. When angiogenesis inhibitor suramin was added before tube formation, formation of vascular structure was blocked. Additionally, Flk1(+)CD31(-)CD34(-) cells cultured on hematopoietic condition could differentiate into hematopoietic cells which expressed GATA-1, 2, and gamma, beta globin gene. After being replated in methylcellulose medium, they formed typical erythroid colonies.

CONCLUSIONS

Flk1(+)CD31(-)CD34(-) cells derived from fetal BM could differentiate into endothelial and hematopoietic cells. The results suggested that these Flk1(+)CD31(-)CD34(-) cells after embryo stage bear characteristics of hemangioblast and may have potential application for the hematopoietic and vascular diseases.

Raloxifene versus continuous combined estrogen/progestin therapy: densitometric and biochemical effects in healthy postmenopausal Taiwanese women

We treated 116 healthy postmenopausal women (age 47-66 years, mean 57 years) in Taiwan with either raloxifene (RLX) 60 mg (n = 92) or 0.625 mg conjugated equine estrogen plus 5 mg medroxyprogesterone acetate (CCEP, n = 24) daily for 12 months in a randomized, double-masked, active-controlled fashion. The results showed that both regimens increased bone mineral density (BMD) at hip sites (means: RLX 2.5-4.9%, CCEP 4.6-7.9%, all p<0.005 compared with baseline), and the difference between the two regimens was not significant. The spinal BMD increased significantly in both groups (1.4% with RLX and 6.0% with CCEP, both p<0.01), and more with CCEP (p<0.003). Osteocalcin levels and urinary type I collagen C-telopeptide/creatinine ratios decreased significantly in both regimens, but the decreases were significantly larger with CCEP. Compared with baseline, both RLX and CCEP decreased the total cholesterol (median 4.9% and 8.6% respectively, p<0.001) and LDL-cholesterol (median 11% and 19% respectively, p<0.001), and increased HDL-cholesterol (median 8.6% and 10.7% respectively, p<0.01). Both regimens increased triglyceride levels (median 3.2% and 18.9% respectively, both p<0.05), although to a lesser extent with RLX than with CCEP (p<0.05). Only 3 subjects (3.3%) reported vaginal bleeding in the RLX group, as compared with 31% (7/22) with CCEP (p<0.05). We conclude that in healthy, postmenopausal Taiwanese women, RLX 60 mg given daily has favorable results in BMD, bone turnover and serum lipids, although the dosage we used showed a potency less than that of conventional CCEP.

A novel member of the RBCC family, Trif, expressed specifically in the spermatids of mouse testis

Members of the RING finger family are implicated in a variety of functions such as signal transduction, transcriptional regulation and other developmental processes. Using degenerate oligonucleotide primers corresponding to the RING domain, we isolated a novel RING finger gene from the mouse testis cDNA library, which was about 1.8 kb and was termed Trif (testis-specific ring finger). This deduced protein contains an N-terminal RING-finger, a B-box, and a C-terminal B-30.2-like domain, which make the Trif protein a member of the RING finger-B-box-coil-coil family. Northern blot analysis of adult multiple tissues indicated that Trif is expressed predominantly in the testis. Further analysis detected Trif transcripts in the testis from day 20 of the postnatal stage. In situ hybridization indicated that Trif is expressed in the round spermatids of the seminiferous tubules. These expression data suggest that Trif may play an important role in the regulation of spermatogenesis.

Spz1, a novel bHLH-Zip protein, is specifically expressed in testis

We isolated a novel bHLH-Zip gene designated Spz1 from a mouse testis cDNA library. Spz1 is expressed specifically in the testis and epididymis. Immunofluorescence staining detected Spz1 protein in the nuclei of LFG6 Leydig cells. The ability of Spz1 protein to bind to the bHLH consensus-binding site, the E-box, was confirmed by EMSA, and a 9-bp asymmetric target site was identified by random selection and PCR amplification. Hormonal regulation of Spz1 was investigated and downregulation of Spz1 expression by testosterone and retinoic acid was found. This nuclear transcription factor may play a crucial role in spermatogenesis by regulating cell proliferation or differentiation through binding to specific DNA sequences like other bHLH-Zip molecules.

Anticancer activity evaluation of the solanum glycoalkaloid solamargine. Triggering apoptosis in human hepatoma cells

Solamargine, an herbal and molluscicidal medicine derived from Solanum incanum, is a steroidal alkaloid glycoside. To characterize the anticancer mechanism of solamargine on human hepatoma cells (Hep3B), changes of cell morphology, DNA content, and gene expression of cells after solamargine treatment were studied. The appearance in solamargine-treated cells of chromatin condensation, DNA fragmentation, and a sub-G(1) peak in a DNA histogram suggests that solamargine induces cell death by apoptosis. The maximum number of dead Hep3B cells was detected within 2 hr of incubation with constant concentrations of solamargine, and no further cell death was observed after an extended incubation with solamargine, indicating that the action of solamargine was irreversible. To determine the susceptibility of cell phases to solamargine-mediated apoptosis, Hep3B cells were synchronized at defined cell cycles by cyclosporin A, colchicine, and genistein, followed by solamargine treatment. The IC(50) values of solamargine for control, G(0)/G(1)-, M-, and G(2)/M-synchronized Hep3B cells were 5.0, > 10, 3.7, and 3.1 microg/mL, implying that cells in the G(2)/M phases are relatively susceptible to solamargine-mediated apoptosis. In addition, a parallel up-regulation of tumor necrosis factor receptor (TNFR)-I and -II on Hep3B cells was detected after solamargine treatment, and the solamargine-mediated cytotoxicity could be neutralized with either TNFR-I or -II specific antibody. Therefore, these results reveal that the actions of TNFR-I and -II on Hep3B cells may be independent, and both are involved in the mechanism of solamargine-mediated apoptosis.

Effects of alendronate on osteopenic postmenopausal Chinese women

To evaluate the effects of alendronate on postmenopausal Chinese women with osteopenia, we treated 46 subjects daily with either 10 mg alendronate (N = 24) or placebo plus 500 mg calcium supplement (N = 22), and measured their bone mineral density (BMD) at the lumbar spine and hip, and urinary bone resorption markers before, during, and after the 1 year treatment period. The bone markers included N-telopeptide of type I collagen (NTx) and deoxypyridinoline (Dpd); both were corrected by the concentration of creatinine in the same sample (NTx/Cr and Dpd/Cr). Both NTx/Cr and Dpd/Cr decreased significantly by 44% and 28%, respectively (p < 0.05 for both), in 1 month in the active treatment group but did not change in the placebo group. BMD at the spine, femoral neck, trochanter, and Ward's triangle increased significantly by 6 months and showed a further increase through month 12 at the spine in the alendronate-treated group. Relative to the placebo group, BMD changes at various sites in the alendronate-treated group were higher at 12 months by 6%-11%. Thus, our data suggest that 10 mg alendronate daily resulted in significant increases in spine and hip BMD, and decreases of urinary resorption markers in the osteopenic postmenopausal Chinese women studied. The amplitude of responses was higher than in previous reports in the USA and Europe.

Interword spacing in Chinese text layout

Three experiments using Chinese text were conducted to investigate word spacing and its effect on reading performance. In Exp. 1, a sonogram detector was used to analyze interword and intercharacter (within a word) time intervals from text read aloud by professional TV broadcasters versus college graduates. The results showed interword intervals were significantly longer than intercharacter intervals, indicating that interword spacing has psychological reality in speech. Exp. 2 examined the effect on reading performance due to separating the characters that compose a word. Separating the characters of a word did not decrease reading accuracy but did result in significantly longer reading times. Exp. 3 explored the effect of word spacing in Chinese sentences on reading performance. Analysis showed that word spacing did not affect reading accuracy, but half character and whole-character spacing significantly reduced reading time. The results of the present study suggest that word spacing in Chinese text layout enhances reading performance. Word spacing may help the reader to segment more quickly a string of characters into words and reduce the likelihood of misinterpretation. Also, ambiguity of sentence structure severely degraded reading accuracy. The implications of the results for word spacing design in Chinese text are discussed.