Cardiovascular Manifestations of Multisystem Inflammatory Syndrome in Children: A Single-Center Bulgarian Study.

Background and objectives: Multisystem inflammatory syndrome in children (MIS-C) poses challenges to the healthcare system, especially with frequent heart involvement. The current retrospective observational study aims to summarize the type and degree of cardiovascular involvement in children with MISC and to find possible associations between laboratory, inflammatory, and imaging abnormalities and the predominant clinical phenotype using a cluster analysis. Material and methods: We present a retrospective observational single-center study including 51 children meeting the MIS-C criteria. Results: Fifty-three percent of subjects presented with at least one sign of cardiovascular involvement (i.e., arterial hypotension, heart failure, pericardial effusion, myocardial dysfunction, pericarditis without effusion, myocarditis, coronaritis, palpitations, and ECG abnormalities). Acute pericarditis was found in 30/41 of the children (73%) assessed using imaging: 14/30 (46.7%) with small pericardial effusion and 16/30 (53.3%) without pericardial effusion. The levels of CRP were significantly elevated in the children with pericarditis (21.6 ± 13 mg/dL vs. 13.9 ± 11 mg/dL, p = 0.035), and the serum levels of IL-6 were higher in the children with small pericardial effusion compared to those without (191 ± 53 ng/L vs. 88 ± 27 ng/L, p = 0.041). Pericarditis with detectable pericardial effusion was significantly more frequent in the female vs. male subjects, 72% vs. 30% (p = 0.007). The hierarchical clustering analysis showed two clusters: Cluster 1 includes the children without cardiovascular symptoms, and Cluster 2 generalizes the MIS-C children with mild and severe cardiovascular involvement, combining pericarditis, myocarditis, heart failure, and low blood pressure. Also, subjects from Cluster 2 displayed significantly elevated levels of fibrinogen (5.7 ± 0.3 vs. 4.6 ± 0.3, p = 0.03) and IL-6 (158 ± 36 ng/mL vs. 66 ± 22 ng/mL, p = 0.032), inflammatory markers suggestive of a cytokine storm. Conclusions: Our results confirm that children with oligosymptomatic MIS-C or those suspected of long COVID-19 should be screened for possible cardiological involvement.

An annotated checklist and key to the Bulgarian cockroaches (Dictyoptera: Blattodea).

An annotated checklist of the Bulgarian species of cockroaches is prepared based on a full published scientific record and own unpublished data. According to the current state of knowledge the Bulgarian cockroach fauna includes 17 species and subspecies. One synonymization is established-Phyllodromica marginata erythronota Br. v. W., syn. n. = Ph. marginata. Two species (Capraiellus tamaninii and Supella longipalpa) are recorded for the first time for this country and other three (Ectobius punctatissimus, Phyllodromica subaptera and Phyllodromica pallida) are eliminated from the list of the Bulgarian fauna. The list is complemented with maps and full locality data and a dichotomic identification key for the studied taxa is presented.

Molecular basis of beta-thalassemia and other hemoglobinopathies in Bulgaria: an update.

beta-Thalassemia (thal) is relatively common in Bulgaria. Over the past 40 years population studies have been carried out in most parts of the country. Different approaches for the detection of beta-thal carriers were used and a frequency from 0.5 to 19.9% was found. We have been studying beta-thal in Bulgaria since 1965 and, based on our results, the average frequency is 2.5%. Here we update our results on the molecular basis of beta-thal and include some unpublished data. One thousand seven hundred and fifty-two patients with signs of hemolysis were studied. Among these, 723 patients (41.3%) had beta-thal or a related condition. In addition, blood samples from 875 newborn babies were studied. Eighteen different beta-thal alleles were identified. The codon 39 (C-->T) and IVS-I-110 (G-->A) mutations occurred most frequently, and seven additional mutations were observed that were present at frequencies of 2.4 to 14.2%. This broad spectrum of beta-thal alleles complicates the analysis for institutions involved in prenatal diagnosis. The frequency of alpha-thal is low (0.5% alpha-thal-1 and 1.6% for alpha-thal-2).

Hb Stara Zagora: a new hyper-unstable hemoglobin causing severe hemolytic anemia.

We describe a new hyper-unstable beta chain variant (codons 137-139, -6 bp) in a 2-year-old Bulgarian boy. The abnormal hemoglobin (Hb) is associated with severe hemolytic anemia as a consequence of its hyper instability. The child was admitted to the Pediatric Clinic (Faculty of Medicine, Stara Zagora, Bulgaria) at the age of 2 months. Because of anemia (Hb 6.9 g/dL) and high serum iron level (58 microM/L) the child was transfused. However, a month later his Hb level had dropped to 7.5 g/dL, and since then he has been on a regular monthly blood transfusion regimen. Hemoglobin analysis of a blood sample collected 2 months after the last transfusion at the age of 2 years, revealed no abnormalities except for the presence of inclusion bodies after incubation of peripheral blood with brilliant cresyl blue. Sequencing of the beta-globin gene revealed heterozygosity for a 6 bp deletion (-TGGCTA) at codons 137 [the second and third base pair (bp)], 138 and 139 (the first bp), forming a new codon at position 137 (GAT). This event eliminates three amino acids (Val-Ala-Asn) and introduces a new residue (Asp). It creates a new restriction site for HphI. The parents and his dizygotic twin brother had no history of hemolysis. The paternity of the child was confirmed by DNA analysis.

Diagnostic value of the muscle fiber conduction velocity for evaluation of muscle hypotrophy.

AIM: To find an objective method of evaluation of the thigh muscle hypothrophy in gonarthrosis. MATERIAL AND METHODS: The subjects of the study were 24 patients with gonarthrosis (mean age 58.4 +/- 2.6 years). Of these 8 (33%) were males and 16 (67%) females. The following methods of examination were used: computed tomography (CT) of the thigh musculature--linear measurement and area of the cross-section of the vastus medialis muscle; electromyography--muscle fiber conduction velocity; and measurement of thigh girth. RESULTS: Significant reduction of the cross-section area and linear measurement of the vastus medialis muscle and significant delay of the muscle fiber conduction velocity was found in the symptomatic side compared with the asymptomatic side. No correlation was found between the tape measure of the thigh and cross-section area of the muscle. A significant correlation was found between the cross-section area of the muscle and the fast fiber conduction velocity as well as between the linear measurement of the vastus medialis muscle cross-section and fast fiber conduction velocity. CONCLUSION: The correlation between the macromorphological changes of the vastus medialis muscle assessed by computed tomography and the functional changes detected by electromyography allows the conclusion that the muscle fiber conduction velocity can be used as an objective method of evaluation of muscle atrophy in degenerative joint diseases.

Lack of mutagenic and co-mutagenic effects of magnetic fields during magnetic resonance imaging.

Mutagenic and co-mutagenic effects of static, pulsed bipolar gradient, and high-frequency magnetic fields, as well as combinations of them, were examined using the Ames test. The Ames test using Salmonella typhimurium bacteria, wild-type strain RTA, preincubation assay, without metabolic activation, was performed. All combinations of magnetic fields were tested with and without co-exposure to N-methyl-N'-nitro-N-nitrosoguanidine and benzo[a]pyrene-4,5-oxide, ethylene oxide, carboplatin, or cisplatin. As expected, chemical mutagens caused a clear-cut increase of the revertants in the Ames test. However, neither the static fields nor a combination of a static magnetic field with the time-varying bipolar gradient field or a pulsed high-frequency magnetic field caused an alteration in the number of revertants in the Ames test. No co-mutagenic effect of any magnetic field combination was observed. In conclusion, magnetic fields used during clinical magnetic resonance imaging (MRI) were neither mutagenic nor co-mutagenic.

(De)constructing dimensions.

We construct renormalizable, asymptotically free, four-dimensional gauge theories that dynamically generate a fifth dimension.

[Possible mutagenic effects of magnetic fields]. / Untersuchung eines möglichen mutagenen Potenzials von Magnetfeldern.

AIM: To assess the potential mutagenic effect of static magnetic fields of 1.5 T and 7 T, gradient fields and high frequency magnetic fields. METHOD: We used the Salmonella mutagenicity test (Ames test), which detects mutations in a gene of a histidine-requiring (his-) strain to produce a histidine-independent (his+) strain, Exposure to a static magnetic field of 1.5 T and 7.2 T, in a bipolar magnetic gradient and additionally in a high frequency field took place with and without known genotoxic chemicals. RESULTS: No differences in the number of revertants between the bacterial strains of exposed and control cells could be detected and the exposure with known genotoxic chemicals showed no significant difference in mutagenicity. CONCLUSION: In conclusion our data do not provide evidence that exposure to a static magnetic field exerts effects on the mutagenicity in our standard tester strains and whether the exposure took place in a diagnostic 1.5 T MR scanner which is used in the clinical routine or at 7.2 T which is a much stronger field made no difference. Also an exposure in a gradient field or in a high frequency field did not show any alteration in the number of revertants.

Plasma antioxidants and coronary heart disease: vitamins C and E, and selenium.

The possibility of a relation between plasma antioxidants such as vitamins C and E and selenium, and mortality from coronary heart disease (CHD) was examined. A cross-sectional survey was undertaken of random population samples of apparently healthy middle-aged men in four European regions with differing mortalities from CHD [rate/100,000 for men aged 40-49]: north Karelia (eastern Finland) (n = 99) [212/100,000]; south-west Finland (n = 85) [146/100,000]; Scotland (n = 131) [140/100,000]; and south Italy (n = 80) [43/100,000]. Median (5th-95th percentile) plasma vitamin C concentrations were lower in Scotland: 18.2 (5.7-61.3) microM than in other regions: north Karelia 28.4 (6.2-85.2); south-west Finland 33.5 (5.7-76.6); south Italy 38.0 (10.2-69.8) microM (P less than 0.001). The median levels in the four areas did not however reflect the regional CHD mortality rates. Regional differences in plasma vitamin E levels were also observed: Scottish levels were low 20.0 (12.1-29.3) microM (P less than 0.001) and did not differ between the other areas: 23.0 (16.7-35.1), 22.5 (13.7-31.6) and 23.9 (15.6-41.3) microM respectively. The vitamin E gradient could be explained in part by differences in serum cholesterol. However, cholesterol-adjusted vitamin E levels were low in the three high CHD areas: Scotland 3.41 (2.41-4.62); north Karelia 3.53 (2.67-5.18); south-west Finland 3.53 (2.58-4.92); Italy 4.81 (3.25-5.99) mumol/mmol cholesterol (P less than 0.001). Cholesterol-adjusted vitamin E was not lower in north Karelia, the higher CHD mortality area in Finland. Serum selenium values also varied with the area examined and reported low levels in Finland were confirmed. Nevertheless, selenium levels did not correlate with the reported mortality rates of CHD. Thus in our small cross-cultural study the evidence did not support our hypothesis that plasma antioxidants explain regional differences in CHD mortality.