The impact of COVID-19 pandemic on blood supplies and transfusion services in Eastern Mediterranean Region.

BACKGROUND: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has spurred a global health crisis. The safety and supply of blood during this pandemic has been a concern of blood banks and transfusion services as it is expected to adversely affect blood system activities. We aim to assess the situation in the Eastern Mediterranean Region (EMR) during the first months of the pandemic. MATERIALS AND METHODS: A survey was designed to address blood supply, transfusion demand, and donor management during the coronavirus disease-19 (COVID-19) pandemic. Medical directors of different blood banks were invited to participate. RESULTS: A total of 16 centers participated with representation from 15/19 countries in the region. In total, 75% were from national blood banks. Most centres had a decrease in the blood supply, ranging from 26-50%. Representatives from 14 countries (93.3%) believed that public fear has contributed to a decrease in donations. Most centres (n=12, 75%) had a reduction in transfusion demand, while those who did not, reported heavy involvement in treating patients with underlying haemoglobinopathies and haematological malignancies. Half of the centres activated their contingency plans. Four centres had to alter the blood donor eligibility criteria to meet demands. All centres implemented donor deferral criteria in relation to SARS-CoV-2, but were variable in measures to mitigate the risk of donor and staff exposure. CONCLUSION: Blood services in the region faced variable degrees of blood shortages. We summarize lessons learnt during this pandemic for the blood banks to consider to plan, assess, and respond proportionately to future similar pandemics.

Blood donations mode: Assessment of the Lebanese model.

Voluntary non-remunerated donations remain the cornerstone for a safe and sustainable blood supply. According to the World Health Organization and other international scientific committees, all nations must switch their system of blood collection to voluntary non-remunerated donation. Several other types of blood donations still exist nowadays that will be discussed. Lebanon, similarly to other developing countries, is struggling to achieve 100% voluntary non-remunerated donations for the many existing social, demographic, cultural and economic problems. Replacement donations remain the predominant type, which creates huge burden on both hospital blood banks and patient families. Despite the limited resources, some improvements have been made recently in this field and Lebanon seems to be on the road of achieving 100% voluntary non-remunerated blood donation as requested by the World Health Organization. The Lebanese experience is worth sharing so that neighbouring countries facing similar problems could benefit from it.

Effect of the carbon dioxide 10,600-nm laser and topical fluoride gel application on enamel microstructure and microhardness after acid challenge: an in vitro study.

The aim of this in-vitro study was to evaluate positive effects of the carbon dioxide laser (CO2, 10,600 nm) with acidulated phosphate fluoride (APF) gel on enamel acid resistance. Twenty extracted human third molars (40 surfaces) were randomly assigned into four groups: group C, untreated control; group L, CO2 laser alone group; group F, APF 1.23% fluoride gel; and group FL, APF 1.23% gel and laser. Samples from group L were irradiated with a CO2 laser for 30s. The parameter settings used were average power, 0.73 W; time on, 100 µs; time off, 40 ms; tip-to-tissue distance, 20 mm; tip diameter 700 µm; and energy density with movements, 5 J/cm2. Samples from group F were treated with the APF gel for 4 min, and the gel was washed off with distilled water. The enamel samples from group FL were treated with APF gel for 4 min and then irradiated with the CO2 laser for 30s without removing the gel. Each enamel sample was placed in 50 ml soft drink (pH = 2.75) for 10 min then rinsed with deionized water and stored in artificial saliva at 37 °C for 1 h. Samples were assessed for Vickers hardness number (VHN) before and after treatments and subjected to SEM analysis. Data were analyzed using a one-way analysis of variance (ANOVA) and Tukey's test (α < 0.05). After the acid challenge, the untreated C group was demineralized to a great extent and the enamel surface was with the lowest mean score of microhardness. The observed VHN in the control (C group) had a mean value of 176.13, the scores in the CO2 laser group (L group) were with mean value of 238.40, the F group with a mean value of 218.45, and the fluoride-treated and laser-irradiated FL group-with a mean of 268.28 VHN. Paired t test performed to compare groups C, L, F, and FL has shown that group FL has greater resistance to decrease in microhardness of dental enamel (P ≤ 0.05) on exposure to acidic protocol. After the acid challenge, the fluoride-treated and laser-irradiated samples (group FL) showed the least diminution in enamel surface microhardness. The sub-ablative carbon dioxide laser irradiation in combination with fluoride treatment is more effective in protecting enamel surface and resisting demineralization than CO2 laser irradiation or fluoride alone.

[Efficacy of candesartan cilexetil in hypertensive patients with or without diabetes]. / Efficacité du candesartan cilexetil chez les hypertendus diabétiques ou non diabétiques.

OBJECTIVE: To assess the effect of an ARB, candesartan cilexetil (CC), on blood pressure (BP) from 5 double-blind, randomised, studies in hypertensive patients. METHODS: Similar design was used in the 5 selected studies. Following 2-4 weeks run-in period with placebo, patients were randomised to receive the double-blind treatment. BP were assessed at inclusion, after 4-6 weeks and at the end (8-12 weeks). Depending on the BP response, dosage of CC 8 mg was doubled at the follow-up visit if BP >or=140/90 mmHg. RESULTS: 702 patients were randomised in CC group of whom 22% (153) were diabetic. Mean BP was 160 +/- 13/94 +/- 10/65 +/- 14 mmHg for SBP/DBP/PP at inclusion and were significantly reduced to 141 +/- 15/83 +/- 10/58 +/- 13 mmHg (p<0.001) after 8-12 weeks. The results according to the diabetes status are presented in the table below: [table: see text] CONCLUSION: Results of this meta analysis analysis performed on individual data show that CC reduces significantly BP in hypertensive population with a significant decrease in the diabetic patients.

Ageing and blood pressure modulate the relationship between metabolic syndrome and aortic stiffness in never-treated essential hypertensive patients. A comparative study.

OBJECTIVE: The aim of this study was to evaluate the impact of the metabolic syndrome (MS) and its components as defined by the National Cholesterol Education Program Adult Treatment Panel III on arterial stiffness in untreated hypertensive patients. METHODS: This was a cross sectional multi-center study performed in 46 healthcare centers, from 14 countries involved in the Complior study. Four hundred and forty patients (55% male) aged 18-73 years, with untreated essential hypertension were selected at inclusion. All patients underwent a full evaluation for all the risk factors representing the MS and an assessment of arterial stiffness using automatic measurement of carotid-femoral pulse wave velocity (PWV). RESULTS: In the overall population significant correlations were found, respectively, between PWV, MS (R=0.2, P<0.001) and gender (R=0.11, P=0.023) where PWV was higher in women. After adjustment for age and systolic blood pressure (SBP), analysis of covariance showed an independent effect of the MS on PWV, this effect increased with ageing and SBP especially after 47 years (age median, P=0.0047). Moreover, increase of mean PWV was highly associated with the number of MS factors in global population (P<0.001). These findings suggest that MS leads to early arterial wall ageing. CONCLUSIONS: Presence of MS induces an increase of arterial stiffness in untreated hypertensive patients independently from age and SBP. The increase of PWV is proportional to number of risk factors and affects principally patients after mid-age of 47 years where MS has ageing effects on arterial stiffness.

The global regulatory protein FruR modulates the direction of carbon flow in Escherichia coli.

The Escherichia coli fructose repressor, FruR, is known to regulate expression of several genes concerned with carbon utilization. Using a previously derived consensus sequence for FruR binding, additional potential operators were identified and tested for FruR binding in DNA band migration retardation assays. Operators in the control regions of operons concerned with carbon metabolism bound FruR, while those in operons not concerned with carbon metabolism did not. In vivo assays with transcriptional lacZ fusions showed that FruR controls the expression of FruR operator-containing genes encoding key enzymes of virtually every major pathway of carbon metabolism. Moreover, a fruR null mutation altered the rates of utilization of at least 36 carbon sources. In general, oxidation rates for glycolytic substances were enhanced while those for gluconeogenic substances were depressed. Alignment of FruR operators revealed that the consensus sequence for FruR binding is the same for operons that are activated and repressed by FruR and permitted formulation of a revised FruR-binding consensus sequence. The reported observations indicate that FruR modulates the direction of carbon flow by transcriptional activation of genes encoding enzymes concerned with oxidative and gluconeogenic carbon flow and by repression of those concerned with fermentative carbon flow.

Four sarcomeric myosin heavy chain genes are expressed by human fetal skeletal muscle cells differentiating in culture.

Expression of four sarcomeric myosin heavy chain (MHC) genes was examined in continuously passaged human fetal (18-22 week) skeletal myoblasts and in myoblasts induced to differentiate by low mitogen medium. Although embryonic MHC mRNA predominated at all time points following induction, three additional MHC genes were expressed at lower levels. These consisted of perinatal, slow, and fast skeletal MHC genes. Temporal regulation of MHC gene expression was observed. In myoblasts and early induced cultures, embryonic and fast transcripts were detected, accompanied in later induced cultures by the accumulation of perinatal and slow MHC transcripts. In situ hybridization analysis of uninduced cells revealed that sarcomeric MHC transcripts originated from a small population of spontaneously fused multinucleated cells. Taken together, these observations demonstrate that human fetal myoblasts induced to differentiate in culture execute a developmental program that includes temporally regulated expression of four distinct sarcomeric MHC genes.

Generation of a full-length human perinatal myosin heavy-chain-encoding cDNA.

Vertebrate sarcomeric myosin heavy chains (MHC) are encoded by multigene families whose members show tissue-specific and developmentally-regulated patterns of expression. Molecular genetic studies have allowed the cloning of a small number of complete genes or cDNAs encoding MHC isoforms [see Warrick and Spudich, Annu. Rev. Cell Biol. 3 (1987) 379-421]. Reported here is the isolation and sequence of a 2.6-kb cDNA that encodes the subfragment 1 or head of a human perinatal skeletal MHC. A cDNA sequence encoding the rod portion of this isoform has been previously reported [Feghali and Leinwand, J. Cell Biol. 108 (1989) 1791-1797]. Polymerase chain reaction with fetal skeletal muscle RNA was used to join the two nonoverlapping cDNA sequences to construct a full-length sequence. The gene encoding the perinatal skeletal MHC has been localized to the cluster of skeletal MHC-encoding genes on chromosome 17.

Molecular genetic characterization of a developmentally regulated human perinatal myosin heavy chain.

We have isolated a human cDNA which corresponds to a developmentally regulated sarcomeric myosin heavy chain. RNA hybridization and DNA sequence analysis indicate that this cDNA, called SMHCP, encodes a perinatal myosin heavy chain isoform. The nucleotide and deduced amino acid sequences of the 3.4-kb cDNA insert show strong homology with other sarcomeric myosin heavy chains. The strongest homology is to a previously described 970-bp cDNA encoding a rat perinatal isoform (Periasamy, M., D. F. Wieczorek, and B. Nadal-Ginard. 1984. J. Biol. Chem. 259:13573-13578). The homology between the analogous human and rat perinatal myosin heavy chain cDNAs is maintained through the highly isoform-specific final 20 carboxyl-terminal amino acids, as well as the 3' untranslated region. Ribonuclease protection studies show that the mRNA encoding this isoform is expressed at high levels in 21-wk fetal skeletal tissue and not in fetal cardiac muscle. In contrast to the rat perinatal isoform, which was not found to be expressed in adult hind-leg tissue, the gene encoding SMHCP continues to be expressed in adult human skeletal tissue, but at lower levels relative to fetal skeletal tissue.

Human cardiac myosin heavy chain genes and their linkage in the genome.

Human myosin heavy chains are encoded by a multigene family consisting of at least 10 members. A gene-specific oligonucleotide has been used to isolate the human beta myosin heavy chain gene from a group of twelve nonoverlapping genomic clones. We have shown that this gene (which is expressed in both cardiac and skeletal muscle) is located 3.6kb upstream of the alpha cardiac myosin gene. We find that DNA sequences located upstream of rat and human alpha cardiac myosin heavy chain genes are very homologous over a 300bp region. Analogous regions of two other myosin genes expressed in different muscles (cardiac and skeletal) show no such homology to each other. While a human skeletal muscle myosin heavy chain gene cluster is located on chromosome 17, we show that the beta and alpha human cardiac myosin heavy chain genes are located on chromosome 14.

Cytoplasmic myosin from Drosophila melanogaster.

Myosin is identified and purified from three different established Drosophila melanogaster cell lines (Schneider's lines 2 and 3 and Kc). Purification entails lysis in a low salt, sucrose buffer that contains ATP, chromatography on DEAE-cellulose, precipitation with actin in the absence of ATP, gel filtration in a discontinuous KI-KCl buffer system, and hydroxylapatite chromatography. Yield of pure cytoplasmic myosin is 5-10%. This protein is identified as myosin by its cross-reactivity with two monoclonal antibodies against human platelet myosin, the molecular weight of its heavy chain, its two light chains, its behavior on gel filtration, its ATP-dependent affinity for actin, its characteristic ATPase activity, its molecular morphology as demonstrated by platinum shadowing, and its ability to form bipolar filaments. The molecular weight of the cytoplasmic myosin's light chains and peptide mapping and immunochemical analysis of its heavy chains demonstrate that this myosin, purified from Drosophila cell lines, is distinct from Drosophila muscle myosin. Two-dimensional thin layer maps of complete proteolytic digests of iodinated muscle and cytoplasmic myosin heavy chains demonstrate that, while the two myosins have some tryptic and alpha-chymotryptic peptides in common, most peptides migrate with unique mobility. One-dimensional peptide maps of SDS PAGE purified myosin heavy chain confirm these structural data. Polyclonal antiserum raised and reacted against Drosophila myosin isolated from cell lines cross-reacts only weakly with Drosophila muscle myosin isolated from the thoraces of adult Drosophila. Polyclonal antiserum raised against Drosophila muscle myosin behaves in a reciprocal fashion. Taken together our data suggest that the myosin purified from Drosophila cell lines is a bona fide cytoplasmic myosin and is very likely the product of a different myosin gene than the muscle myosin heavy chain gene that has been previously identified and characterized.