Sleep Quality and Its Relationship to Anxiety and Hardiness in a Cohort of Frontline Italian Nurses during the First Wave of the COVID-19 Pandemic

INTRODUCTION

The COVID-19 pandemic has had a considerable impact on the psychological and psychopathological status of the population and health care workers in terms of insomnia, anxiety, depression, and post-traumatic stress disorder. The primary aim of this study was to describe and evaluate the impact of the pandemic on insomnia levels of a cohort of Italian nurses, particularly those involved in the care of COVID-19 patients. The secondary aim was to identify the interaction between insomnia and hardiness, anxiety, and sleep disturbances.

MATERIALS AND METHODS

A descriptive-exploratory study was conducted using an online survey during the first wave of the COVID-19 pandemic (March to July 2020). The questionnaire consisted of multiple-choice, open-ended, closed, and semi-closed questions. The psychometric tools administered were the Dispositional Resilience Scale (DRS-15), the State-Trait Anxiety Inventory (STAI-Y), and the Insomnia Severity Index (ISI).

RESULTS

a cohort of 1167 nurses fully completed the questionnaire (86.2% of total respondents). The insomnia scale survey showed an increase in post-pandemic scores compared to those before the pandemic, implying that insomnia levels increased after the first pandemic wave. Insomnia scores were directly correlated with anxiety levels (r = 0.571; p ≤ 0.05) and inversely correlated with hardiness levels (r = -0.324; p < 0.001). Multivariate analysis revealed the following protective factors: not having worked in COVID-19 wards, high levels of hardiness (commitment), and the presence of high pre-pandemic insomnia disorder. The main risk factor for insomnia reported in the analysis was a high anxiety score.

DISCUSSION AND CONCLUSION

Anxiety represented the main risk factor for insomnia severity in our sample, while hardiness was confirmed as a protective factor. Thus, it is necessary to design further studies to identify additional risk factors for poor sleep quality and to develop educational courses and strategies aimed at enhancing rest and sleep quality, especially for frontline nurses.

The Effectiveness of NIV and CPAP Training on the Job in COVID-19 Acute Care Wards: A Nurses' Self-Assessment of Skills

Background: Noninvasive ventilation (NIV) in COVID-19 patients outside of intensive care unit (ICU) settings was a feasible support during the pandemic outbreak. The aim of this study was to assess the effectiveness of an “on the job” NIV training program provided to 66 nurses working in 3 COVID-19 wards in an Italian university hospital. Methods: A quasi-experimental longitudinal before−after study was designed. The NIV Team education program, provided by expert ICU nurses, included: 3 h sessions of training on the job during work-shifts about the management of helmet-continuous positive airway pressure (CPAP) Venturi systems, and NIV with oronasal and full-face masks. An eleven-item “brief skills self-report tool” was administered before and after the program to explore the perception of NIV education program attendees about their level of skills. Results: In total, 59 nurses responded to the questionnaire. There was an improvement in the skill levels of the management of Helmet-CPAP (median before training 2, inter-quartile range (IQR) 0−6; median after training 8, IQR 3−9; p < 0.0001), and mask-NIV (median before training 2, IQR 0−6; median after training 8, IQR 3−9; p < 0.0001). Conclusions: Training on the job performed by expert ICU nurses can be a valuable and fast means to implement new Helmet-CPAP and mask-NIV skills outside of ICUs.

[Unplanned extubations in adult intensive care units: an update]

INTRODUCTION

Unplanned extubations (UEs) in adult Intensive Care Units (ICUs), have recently become an indicator of quality and safety of care.

METHOD

A literature review published 10 years ago was updated to analyze any changes in UEs.

RESULTS

The cumulative incidence of UEs varied between 0.3% and 27%, before 2000, and more recently, from 0.5% to 35.8%, without substantial changes. The rate of Self Extubations (SE) outweighed the Accidental Extubation (AE), amounting to 50%-100% of all UE. The reintubations rate ranged between 1.81% and 88%. The UEs increase the length of the mechanical ventilation, of ICU and hospital stay, and according to few studies the rate of death with UEs is lower. Major risk factors for UE are: APACHE II score ≥17, agitation, physical restraints, administration of midazolam, and higher levels of consciousness. The implementation of ABCDE bundle in ICUs did not involve additional risks of UE. The prevention includes a sedation with drugs different from benzodiazepines, an early detection of patients' readiness to weaning trial from mechanical ventilation, and the adequate stabilization of the endotracheal tube, with securing systems passing behind the patient's neck. The use of physical restraints is inconsistent, since it can be a risk factor for SE.

CONCLUSIONS

For preventing UEs the surveillance of nursing staff is fundamental, if the staffing is adequate to the real workloads in ICU.

Cocaine administration prior to reactivation facilitates later acquisition of an avoidance response in rats

The effect of cocaine administered prior to memory reactivation on the subsequent acquisition of an avoidance response was investigated. Two noncontingent footshocks were administered to rats in the black compartment of a one-way avoidance chamber. Twenty-four hours later, cocaine or saline was administered 5 min prior to a 30-s reactivation treatment consisting of re-exposure to selected stimuli present during the initial conditioning. Subjects were trained 24 h later to move from the chamber's black compartment to its white compartment in order to avoid a footshock. Intermediate (5.0 or 7.5 mg/kg IP), but not low (3.3 mg/kg IP) or high (11.25 or 16.88 mg/kg IP), doses of cocaine given prior to the reactivation treatment enhanced later acquisition of the one-way avoidance response. These results suggest that cocaine administered prior to the reintroduction of cues associated with a conditioning episode can modulate memory processes, and that the dose-response function for this effect is U-shaped. The avoidance performance of rats that received cocaine (5.0 mg/kg IP) 3 h after the reactivation treatment did not differ from that of saline-treated control subjects, suggesting that the conjoint neural activity elicited by cocaine and exogenous retrieval cues is necessary for potentiation of memory retrieval or reconstruction processes.

Thermoregulatory reflexes and cutaneous active vasodilation during heat stress in hypertensive humans

During dynamic exercise in the heat, increases in skin blood flow are attenuated in hypertensive subjects when compared with normotensive subjects. We studied responses to passive heat stress (water-perfused suits) in eight hypertensive and eight normotensive subjects. Forearm blood flow was measured by venous-occlusion plethysmography, mean arterial pressure (MAP) was measured by Finapres, and forearm vascular conductance (FVC) was calculated. Bretylium tosylate (BT) iontophoresis was used to block active vasoconstriction in a small area of skin. Skin blood flow was indexed by laser-Doppler flowmetry at BT-treated and untreated sites, and cutaneous vascular conductance was calculated. In normothermia, FVC was lower in hypertensive than in normotensive subjects (P < 0.01). During heat stress, FVC rose to similar levels in both groups (P > 0.80); concurrent cutaneous vascular conductance increases were unaffected by BT treatment (P > 0.60). MAP was greater in hypertensive than in normotensive subjects during normothermia (P < 0.05, hypertensive vs. normotensive subjects). During hyperthermia, MAP fell in hypertensive subjects but showed no statistically significant change in normotensive subjects (P < 0.05, hypertensive vs. normotensive subjects). The internal temperature at which vasodilation began did not differ between groups (P > 0.80). FVC is reduced during normothermia in unmedicated hypertensive subjects; however, they respond to passive heat stress in a fashion no different from normotensive subjects.

Derepressed utilization of L-malic acid and succinic acid by mutants of Pachysolen tannophilus

Utilization of the tricarboxylic acid (TCA) cycle intermediates, L-malic acid and succinic acid, by the yeast Pachysolen tannophilus is repressed in the presence of glucose. Strains of P. tannophilus containing mutations in two hexokinases and a glucokinase were characterized for growth on glucose plus L-malic acid or succinic acid. Increased specific utilization rates of malic acid and succinic acid in the presence of glucose were observed in mutants containing a lesion in hexokinase A, an enzyme associated with catabolite repression. Such derepressed mutants may have application in winemaking in which utilization of a major grape acid, L-malic acid, is often desirable for acidity reduction.

Aflatoxin variability in pistachios

Pistachio fruit components, including hulls (mesocarps and epicarps), seed coats (testas), and kernels (seeds), all contribute to variable aflatoxin content in pistachios. Fresh pistachio kernels were individually inoculated with Aspergillus flavus and incubated 7 or 10 days. Hulled, shelled kernels were either left intact or wounded prior to inoculation. Wounded kernels, with or without the seed coat, were readily colonized by A. flavus and after 10 days of incubation contained 37 times more aflatoxin than similarly treated unwounded kernels. The aflatoxin levels in the individual wounded pistachios were highly variable. Neither fungal colonization nor aflatoxin was detected in intact kernels without seed coats. Intact kernels with seed coats had limited fungal colonization and low aflatoxin concentrations compared with their wounded counterparts. Despite substantial fungal colonization of wounded hulls, aflatoxin was not detected in hulls. Aflatoxin levels were significantly lower in wounded kernels with hulls than in kernels of hulled pistachios. Both the seed coat and a water-soluble extract of hulls suppressed aflatoxin production by A. flavus.

Purification and characterization of urease from schizosaccharomyces pombe

The urease from the ascomycetous fission yeast Schizosaccharomyces pombe was purified about 4000-fold (34% yield) to homogeneity by acetone precipitation, ammonium sulfate precipitation, DEAE-Sepharose ion-exchange column chromatography, and if required, Mono-Q ion-exchange fast protein liquid chromatography. The enzyme was intracellular and only one species of urease was detected by nondenaturing polyacrylamide gel electrophoresis (PAGE). The native enzyme had a M(r) of 212 kDa (Sepharose CL6B-200 gel filtration) and a single subunit was detected with a M(r) of 102 kDa (PAGE with sodium dodecyl sulfate). The subunit stoichiometry was not specifically determined, but the molecular mass estimations indicate that the undissociated enzyme may be a dimer of identical subunits. The specific activity was 700-800 micromols urea.min-1.mg protein-1, the optimum pH for activity was 8.0, and the Km for urea was 1.03 mM. The sequence of the amino terminus was Met-Gln-Pro-Arg-Glu-Leu-His-Lys-Leu-Thr-Leu-His-Gln-Leu-Gly-Ser-Leu-Ala and the sequence of two tryptic peptides of the enzyme were Phe-Ile-Glu-Thr-Asn-Glu-Lys and Leu-Tyr-Ala-Pro-Glu-Asn-Ser-Pro-Gly-Phe-Val-Glu-Val-Leu-Glu-Gly-Glu-Ile- Glu- Leu-Leu-Pro-Asn-Leu-Pro. The N-terminal sequence and physical and kinetic properties indicated that S. pombe urease was more like the plant enzymes than the bacterial ureases.

The plant growth regulator methyl jasmonate inhibits aflatoxin production by Aspergillus flavus

Aflatoxins are highly toxic and carcinogenic compounds produced by certain Aspergillus species on agricultural commodities. The presence of fatty acid hydroperoxides, which can form in plant material either preharvest under stress or postharvest under improper storage conditions, correlates with high levels of aflatoxin production. Effects on fungal growth and aflatoxin production are known for only a few of the numerous plant metabolites of fatty acid hydroperoxides. Jasmonic acid (JA), a plant growth regulator, is a metabolite of 13-hydroperoxylinolenic acid, derived from alpha-linolenic acid. The volatile methyl ester of JA, methyl jasmonate (MeJA), is also a plant growth regulator. In this study we report the effect of MeJA on aflatoxin production and growth of Aspergillus flavus. MeJA at concentrations of 10(-3)-10(-8) M in the growth medium inhibited aflatoxin production, by as much as 96%. Exposure of cultures to MeJA vapour similarly inhibited aflatoxin production. The amount of aflatoxin produced depended on the timing of the exposure. MeJA treatment also delayed spore germination and inhibited the production of a mycelial pigment. These fungal responses resemble plant jasmonate responses.

Inhibition of Aflatoxin Production by Surfactants

The effect of 12 surfactants on aflatoxin production, growth, and conidial germination by the fungus Aspergillus flavus is reported. Five nonionic surfactants, Triton X-100, Tergitol NP-7, Tergitol NP-10, polyoxyethylene (POE) 10 lauryl ether, and Latron AG-98, reduced aflatoxin production by 96 to 99% at 1% (wt/vol). Colony growth was restricted by the five nonionic surfactants at this concentration. Aflatoxin production was inhibited 31 to 53% by lower concentrations of Triton X-100 (0.001 to 0.0001%) at which colony growth was not affected. Triton X-301, a POE-derived anionic surfactant, had an effect on colony growth and aflatoxin production similar to that of the five POE-derived nonionic surfactants. Sodium dodecyl sulfate (SDS), an anionic surfactant, and dodecyltrimethylammonium bromide, a cationic surfactant, suppressed conidial germination at 1% (wt/vol). SDS had no effect on aflatoxin production or colony growth at 0.001%. The degree of aflatoxin inhibition by a surfactant appears to be a function of the length of the hydrophobic and hydrophilic chains of POE-derived surfactants.

Opioid receptor-dependent long-term potentiation at the lateral perforant path-CA3 synapse in rat hippocampus

The involvement of opioid receptors in the induction of long-term potentiation (LTP) was investigated in the lateral and medial perforant path projections to area CA3 of the hippocampus in anesthetized rats. The opioid receptor antagonist naloxone (10 nmol), applied to the hippocampal CA3 region 10 min prior to tetanization, blocked the induction lateral perforant path-CA3 LTP induced by high-frequency stimulation. By contrast, LTP induction in medial perforant path-CA3 was not attenuated by a 10 nmol quantity of naloxone. (+)-Naloxone (10 nmol), the inactive stereoisomer of naloxone, was without effect on the induction of lateral perforant path-CA3 LTP. Naloxone applied 1 h following LTP induction did not reverse established lateral perforant path-CA3 LTP, indicating that opioid receptors are involved in the induction but not the maintenance of LTP in this pathway. LTP of medial perforant path responses developed immediately, while LTP of lateral perforant path responses was slow to develop. The latter pattern is similar to the time course of the development of LTP observed at the mossy fiber-CA3 synapse and suggests that lateral and medial perforant path synapses may use distinct mechanisms of both induction and expression of LTP. These data extend previous findings demonstrating opioid receptor-dependent mechanisms of LTP induction at both the mossy fiber-CA3 synapse and the lateral perforant path-dentate gyrus synapse. We suggest that lateral perforant path and mossy fiber synapses may utilize similar, opioid receptor-dependent, mechanisms of LTP induction and expression.

Post-reactivation cocaine administration facilitates later acquisition of an avoidance response in rats

We previously demonstrated that cocaine administered immediately prior to a reactivation episode comprised of re-exposure to selected features of the original fear-conditioning session alters subsequent memory retrieval or reconsolidation. In the present study we determined that, similar to pre-reactivation administration, post-reactivation administration of cocaine also alters memory retrieval or reorganization, as measured by subsequent conditioned performance. The dose-response function for this effect of cocaine was U-shaped; maximal enhancement of subsequent avoidance performance was produced by a 7.5 mg/kg i.p. dose of cocaine. Because a dose of lidocaine equimolar to the effective cocaine dose was found not to alter subsequent conditioned performance, the effect of cocaine on memory processing most likely is not attributable to its local anesthetic properties.

Individual variability in Tyr-Gly-Gly formation from enkephalin hydrolysis in mouse plasma

We examined the effects of captopril (an angiotensin-converting enzyme inhibitor) and phosphoramidon (a selective enkephalinase inhibitor) on Tyr-Gly-Gly production during Met-enkephalin hydrolysis in plasma samples taken from individual outbred Swiss-Webster and inbred C57BL/6J and DBA/2J mice. Discriminant analysis procedures identified three distinct plasma profiles of Tyr-Gly-Gly production in all strains of mice: a captopril-sensitive/phosphoramidon-insensitive profile, a captopril-insensitive/phosphoramidon-sensitive profile, and a moderate captopril and phosphoramidon sensitivity profile. The abilities of captopril and phosphoramidon to inhibit Tyr-Gly-Gly production in the same mouse plasma sample were highly inversely correlated (r = -0.938). Plasma of Swiss-Webster mice whose cages and bedding had been changed 24 h prior to sample collection was significantly more likely to exhibit the captopril-sensitive/phosphoramidon-insensitive profile than the plasma of mice whose cages/bedding had not been changed for at least 5 days. The results suggest that environmental novelty may dramatically alter the activity of a plasma dipeptidyl carboxypeptidase system, and thereby regulate behavioral and physiological responses to novel experiences.

Mu opioid receptors are associated with the induction of hippocampal mossy fiber long-term potentiation

We assessed the effects of antagonists selective for mu (mu), delta (delta) or kappa (kappa) opioid receptors on the induction of long-term potentiation (LTP) and short-term potentiation (STP) at the rat hippocampal mossy fiber-CA3 synapse in vivo. The mu opioid receptor-selective antagonist Cys2,Tyr3,Orn5,Pen7 amide (CTOP, 1 or 3 nmol) did not alter either mossy fiber-CA3 responses evoked at low frequencies or previously potentiated mossy fiber-CA3 responses, but it attenuated the induction of mossy fiber LTP in a dose-dependent manner. By contrast, LTP of CA3 responses evoked by stimulation of commissural afferents to the CA3 region was unaffected by CTOP. Neither the delta opioid receptor-selective antagonist naltrindole hydrochloride (0.3-10 nmol) or the kappa opioid receptor-selective antagonist nor-binaltorphimine hydrochloride (3-10 nmol) altered the induction of mossy fiber LTP. Thus, a role for delta or kappa opioid receptors in the induction of mossy fiber LTP could not be demonstrated. CTOP, in quantities that attenuated mossy fiber LTP induction, also attenuated the magnitude of mossy fiber STP measured 5 sec after delivery of conditioning trains. Further examination of the component of STP corresponding to post-tetanic potentiation (PTP) revealed that CTOP selectively attenuated the estimated magnitude and time constant of decay of mossy fiber PTP. These results suggest that the frequency-dependent activation of mu opioid receptors by endogenous opioid peptides is required for the induction of LTP at hippocampal mossy fiber synapses.(ABSTRACT TRUNCATED AT 250 WORDS)

D-Pen2-[D-Pen5]enkephalin impairs acquisition and enhances retention of a one-way active avoidance response in rats

We reported previously that D-Pen2-[D-Pen5]enkephalin (DPDE), a delta-opioid receptor selective analog of Leu-enkephalin, impairs acquisition of an automated jump-up avoidance response in rats and acquisition of a one-way active avoidance response in mice. In the present study we investigated the effects of DPDPE on one-way avoidance conditioning in rats. The rats received two escape-only trials on day 1 and eight additional training trials on day 2. DPDPE (1.16 micrograms/kg IP) administered prior to training on day 2 impaired acquisition of the avoidance response. On the other hand, DPDPE (0.332 microgram/kg IP) administered following presentation of the two escape-only trials on day 1 significantly enhanced retention, as measured by improved one-way active avoidance performance on day 2. These results indicate that activation of delta-opioid receptors by DPDPE has a modulatory effect on acquisition and retention of aversively motivated performance.

Factors influencing the utilisation of L-malate by yeasts

The utilisation of L-malate and the effect of glucose concentration on malate utilisation under semi-anaerobic conditions were investigated in three yeasts unable to grow on malate as sole carbon source (Saccharomyces cerevisiae, Schizosaccharomyces malidevorans, Zygosaccharomyces bailii) and two yeasts able to utilise the TCA cycle intermediate as sole carbon source (Pichia stipitis and Pachysolen tannophilus). Utilisation of malate by both Schiz. malidevorans and Z. bailii was reduced at high and low levels of glucose. In the absence of glucose, P. stipitis and Pa. tannophilus utilised malate rapidly; however, their utilisation was drastically reduced in the presence of glucose, suggesting that malate utilisation is under catabolite repression.

Location on the Salmonella typhimurium chromosome of the gene encoding nucleoside diphosphokinase (ndk)

The gene encoding nucleosidediphosphate kinase (ndk) was located at 55 units on the Salmonella typhimurium chromosome. The ndk locus was 83% cotransducible with hisS and 2% cotransducible with glyA in phage P22-mediated crosses. A nucleosidediphosphate kinase mutant that produced only 10% of the wild-type enzyme activity (ndk-1) grew normally and produced a heat-labile enzyme.