Myocardial perfusion after COVID-19 infection: No persisting impaired myocardial blood flow in surviving patients

Funding Acknowledgements

Type of funding sources: None.

Background

 Acute myocardial damage is common in hospitalized patients with severe COVID-19, with evidence of myocardial infarction and myocarditis demonstrated on cardiovascular magnetic resonance (CMR). Post-mortem studies have also implicated microvascular thrombosis, which may cause persistent microvascular disease. 

Purpose

 To determine the long-term coronary sequelae in recovered COVID-19 using multiparametric CMR including state-of-the-art inline quantitative stress myocardial blood flow (sMBF) mapping to assess global and regional sMBF.

Methods

 Prospective, multicentre observational study of recovered COVID-19 patients scanned at three London CMR units. Results were compared to a propensity-matched, pre-COVID chest pain cohort (104 patients referred for perfusion CMR, with subsequently demonstrated unobstructed coronary arteries) and 27 healthy volunteers (HV). Perfusion image analysis was performed using a novel artificial intelligence approach deriving global and regional stress and rest MBF with a cut-off of >2.25mL/g/min signifying normal sMBF and <1.82mL/g/min abnormal sMBF (Kotecha JCVI 2019). 

Results

 104 recovered, post-COVID patients (median age 62 years, 76% male; 89[87%] hospitalised, 41/89[46%] requiring ICU) underwent adenosine-stress perfusion CMR at a median 131(IQR 43-179) days from COVID-19 diagnosis. Median LVEF was 67% (IQR 60-71%; 12 (11.5%) with impaired LVEF), 51 patients (49%) had late gadolinium enhancement (LGE); 18% infarct-pattern and 33% non-ischaemic LGE.  Global stress MBF in post-COVID patients was no different to age-, sex- and co-morbidities-matched controls (2.57 ± 0.77 vs. 2.40 ± 0.75 ml/g/min, p = 0.11, Figure 1), though lower than HV (3.00 ± 0.76 ml/g/min, p = 0.001). Post-COVID, multivariate predictors of low sMBF were male sex (OR 0.57, 95%CI 0.41-0.80, p = 0.001) and hypertension (OR 0.67, 95%CI 0.51-0.88, p = 0.004), but not COVID-19 disease severity (ICU admission) or presence of scar (ischemic/non-ischemic).  21/42 with reduced sMBF (<2.25mL/g/min) had regional perfusion defects consistent with epicardial coronary disease.

Conclusions

  COVID-19 survivors do not demonstrate evidence of reduced global MBF by CMR compared to risk factor matched controls. Stress perfusion CMR identifies etiology of acute myocardial damage (infarction/myocarditis) and presence of occult coronary ischemia.

Deformable liposomes as enhancer of caffeine penetration through human skin in a Franz diffusion cell test

OBJECTIVE

The permeation of hydrophilic molecules through the skin is still a challenge due to the barrier posed by stratum corneum, the outermost layer of the skin. Liposomes have frequently been used as carriers for different types of drugs and may also function as permeation enhancers. Propylene glycol has also been used as an edge activator in liposomes to increase the permeation. The aim of this work was to prepare liposomes containing an edge activator and loaded with caffeine to evaluate the potential of caffeine reaching the deeper layers in the skin.

METHODS

The formulations were prepared by a top-down process using high-pressure homogenization at 200 00 psi for 10 min. They were characterized by size, polydispersity index (PI), zeta potential (ZP), pH, caffeine content and encapsulation efficiency (EE%) on preparation (time zero) and after 30 days. Cytotoxicity of blank and loaded liposomes was assessed by MTT proliferation assay with a normal keratinocyte cell line (HaCaT). In vitro permeation tests were performed with human skin in Franz cells over 24 h, and caffeine concentration was determined in the skin surface, stratum corneum, dermo-epidermal fraction and receptor medium by HPLC.

RESULTS

The caffeine liposomes with (DL-Caf) or without propylene glycol (CL-Caf) showed, respectively, mean size 94.5 and 95.4 nm, PI 0.48 and 0.42, ZP + 1.3 and + 18.1 mV and caffeine content of 78.57 and 80.13%. IC₅₀ values of caffeine in DL-Caf (3.59 v/v %) and CL-Caf (3.65 v/v %) were not significantly different from conventional blank liposome (3.27 v/v %). The DL-Caf formulation presented the best capability to enhance the caffeine permeation through the skin, resulting 1.94-folds higher than caffeine solution. Furthermore, the caffeine flux from DL-Caf was 1.56- and 3.05-folds higher than caffeine solution and CL-Caf, respectively. On the other hand, CL-Caf showed the lowest caffeine penetration revealing the importance of edge activator to aid hydrophilic drug penetration to all skin layers.

CONCLUSION

The DL-Caf formulation tested was able to improve the permeation of caffeine through the stratum corneum and dermo-epidermal layers, suggesting that this delivery system may be effective for deep skin delivery of hydrophilic drugs.

Prevalence of and factors associated with burnout among health care professionals in Arab countries: a systematic review

BACKGROUND

Burnout among healthcare professionals is one of the key challenges affecting health care practice and quality of care. This systematic review aims to (1) estimate the prevalence of burnout among health care professionals (HCP) in Arab countries; and (2) explore individual and work-related factors associated with burnout in this population.

METHODS

Multiple electronic databases were searched for studies published in English or Arabic from January 1980 to November 2014 assessing burnout (using the Maslach Burnout Inventory; MBI) amongst health care professionals (HCP) in Arab countries.

RESULTS

Nineteen studies (N = 4108; 49.3% females) conducted on HCP in Bahrain, Egypt, Jordan, Lebanon, Palestine, Saudi Arabia and Yemen were included in this review. There was a wide range of prevalence estimates for the three MBI subscales, high Emotional Exhaustion (20.0-81.0%), high Depersonalization (9.2-80.0%), and low Personal Accomplishment (13.3-85.8%). Gender, nationality, service duration, working hours, and shift patterns were all significantly associated with burnout.

CONCLUSIONS

Within the constraints of the study and the range of quality papers available, our review revealed moderate-to-high estimates of self-reported burnout among HCP in Arab countries that are similar to prevalence estimates in non-Arabic speaking westernized developed countries. In order to develop culturally appropriate interventions, further research using longitudinal designs is needed to confirm the risk factors for burnout in specific HCP settings and specialties in Arab countries.

Class I Integron and β-lactamase encoding genes of multidrug resistance Salmonella isolated from pigeons and their environments

Seroprevalence of Salmonella spp. was investigated in pigeon and its surrounding environment of Sharkia province, Egypt. Samples were randomly collected from fifty freshly dead squabs, forty freshly dead adults pigeons, sixty diseased adult pigeons and 100 apparently healthy adult pigeons. Bacterial isolates were tested for their susceptibility to 17 different antimicrobial discs, by using the disc diffusion method. The bacterial isolates were tested for Class I and β-lactamase encoding genes by using PCR. In vitro sensitivity of all Salmonella isolates were completely resistant to Streptomycin, Amoxicillin, clavulanic acid, Amoxicillin, Ampicillin and Ceftazidime (100%). Class1 integron were characterized in 70% Salmonella isolates from squabs, 42.9 % in adult pigeons and 14.3% in pigeon environment which confer their resistance to streptomycin and ampicillin. Meanwhile TEM-1 β-lactamase was characterized in 20% of tested Salmonella isolates from squabs including S. Entertidis, 42.9% of tested Salmonella isolates from adult pigeons including S. Entertidis which confer their resistance to cephalosporin and not detected in all isolates from pigeons environments. In conclusion TEM-1 β-lactamase was characterized in 20% of Salmonella isolates from squabs while Class1 integron was characterized in 70% Salmonella isolates from squabs.

Topical and cutaneous delivery using nanosystems

The goal of topical and cutaneous delivery is to deliver therapeutic and other substances to a desired target site in the skin at appropriate doses to achieve a safe and efficacious outcome. Normally, however, when the stratum corneum is intact and the skin barrier is uncompromised, this is limited to molecules that are relatively lipophilic, small and uncharged, thereby excluding many potentially useful therapeutic peptides, proteins, vaccines, gene fragments or drug-carrying particles. In this review we will describe how nanosystems are being increasingly exploited for topical and cutaneous delivery, particularly for these previously difficult substances. This is also being driven by the development of novel technologies, which include minimally invasive delivery systems and more precise fabrication techniques. While there is a vast array of nanosystems under development and many undergoing advanced clinical trials, relatively few have achieved full translation to clinical practice. This slow uptake may be due, in part, to the need for a rigorous demonstration of safety in these new nanotechnologies. Some of the safety aspects associated with nanosystems will be considered in this review.

Appropriate concrete for nuclear reactor shielding

A survey for the neutron activation significant trace-minerals in limestones from different sites in Syria has been carried out. The specific saturation activation radioactivity was calculated and compared to the clearance levels. The results show that the limestone composition varies significantly from one site to another. For example Al-Tamoura site has ∑(C(i)/CL(i))≤1 at thermal neutron flux less than 10(7) (n cm(-2) s(-1)), while the limestone from other the three sites has ∑(C(i)/CL(i))≤1 at a flux less than 3×10(6) (n cm(-2) s(-1)).

Lung transplantation in children following bone marrow transplantation: a multi-center experience

Allogenic BMT has been successfully performed as a treatment for hematologic diseases with an expected long-term survival. This survival is truncated by respiratory complications including airway obstruction especially BO. Chronic GVHD has been reported to precede almost all cases reported. LTx has become a therapeutic life-saving option for patients with end-stage lung disease that maybe offered for the treatment of GVHD. We report a multi-center experience of pediatric LTx following BMT in 11 patients age- and gender-matched with 11 controls who received LTx for end-stage lung disease secondary to CF. Overall death was 36.4% over a follow-up period of 19 months (range 3-36 months) for the cases and 27.3% for the control group followed for 17 months (range 8-32 months). Median FEV1 one yr post-transplant for the cases was 78% predicted compared with 67.3% predicted for the controls. The median for episodes of infection was comparable at a median of one episode per patient through the entire follow-up period among both groups. Acute rejection episodes were significantly higher in the control group with a median of one episode per patient in the control group compared to none within the cases. Our data suggest that LTx may be a valuable therapeutic option for children with end-stage lung disease post-BMT with comparable survival outcome to that after LTx in children for other indications such as CF. Hospital stay was significantly longer in our case group. Infection rate was comparable between groups albeit type of infection varied. Significantly and of interest is that acute rejection episodes were non-existent in these cases.

Radiation shielding concrete made of Basalt aggregates

In spite of the fact that Basalt is a widespread type of rock, there is very little available information on using it as aggregates for concrete radiation shielding. This paper investigates the possibility of using Basalt for the aforementioned purpose. The results have shown that Basalt could be used successfully for preparing radiation shielding concrete, but some attention should be paid to the choice of the suitable types of Basalt and for the neutron activation problem that could arise in the concrete shield.

Hyperglycaemia, hypertension and their risk factors among Palestine refugees served by UNRWA

UNRWA's noncommunicable disease screening activities were evaluated among 7762 refugees screened for hypertension and type 2 diabetes in Jordan, Syrian Arab Republic, Lebanon, Gaza Strip and West Bank in June 2007. People were referred for screening most commonly because of age (both sexes), followed by smoking (males) and family history (females). Atotal of 9% ofscreened people were diagnosed with hypertension/ diabetes. Being older than 40 years, obese or with a positive family history of diabetes or cardiovascular disease increased the risk of presenting with hypertension and/or hyperglycaemia 3.5, 1.6 and 1.2 times respectively. Differences in risk factor detection and screening outcome in relation to differences in lifestyle are discussed.

Assessment of public doses due to a neutron calibration bunker

In this work, the expected neutron and gamma doses in the populated areas outside the newly constructed neutron calibration bunker at the Atomic Energy Commission of Syria will be assessed using the Monte Carlo code MCNP-4C2. The results showed that the maximum ambient dose equivalent rate (neutrons and gammas) outside the bunker would not exceed 0.5 microSv h(-1), assuming an Am-Be neutron source of emission rate of 10(8) n s(-1). The neutron dose is approximately 10 times higher than the photon dose. Sky shine contributes by about 25-50% of the neutron dose and 7-27% of the gamma dose, depending on the location. The simulation uncertainty due to the possible variations in the simulation parameters has been given particular importance.

Relapsing life threatening community acquired pneumonia due to rare Legionella species responsive to ceftriaxone and aztreonam

A 24 year old Saudi housewife was admitted thrice with life threatening community acquired pneumonia. Even though she responded to an initial cocktail of cefriaxone, erythromcin, rifampicin and flucloxacillin during the second admission, she relapsed within four days of discharge when she was on erythromycin only. During the third admission she was put on ceftriaxone and aztreonam and recovered fully without any relapse. Serology results received later showed Legionella IgM titres of more than 1:256 for Legionella micdadei and Legionella bozemanii, and IgG titres of Legionella hackeliae. This case demonstrates relapsing pneumonia due to Legionella micdadei and bozemanii infection, and previous exposure to Legionella hackeliae. Both species, that is, Legionella micdadei and bozemanii, are resistant to erythromycin, but responded very well to a combination of ceftriaxone and aztreonam have not been used previously for the treatment of Legionnaires diseases.