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This research examines the impact of the coronavirus index on the returns and volatility of ten major cryptocurrencies during the COVID-19 pandemic. For this purpose, we applied a multivariate volatility GARCH model with an integrated dynamic conditional correlation (DCC) approach to daily cryptocurrency values observed data during the January-December, 2020 period. Moreover, we used the Granger causality test to study return-volume correlations. The findings indicate that cryptocurrency volatility declined after the World Health Organization declared on March 11, 2020, that the coronavirus was a pandemic. Unlike most of the relevant previous studies, we found that the COVID-19 crisis did not have a long-term effect on cryptocurrency returns and volatility but only presented a short-term effect. Our results have implications for investors who need to determine an optimal portfolio for a scenario other than the base.

Background: Zellweger syndrome (ZS) is a peroxisome biogenesis disorder attributed to a mutation of the PEX genes family. The incidence of this disease in Africa and the Arab world remains unknown. This contribution is aimed at describing the clinical phenotype and biochemical features in Tunisian patients with ZS in order to improve the detection and management of this severe disorder. Methods: A total of 52 patients diagnosed with ZS and 60 age- and sex-matched healthy controls were included in this study. Patients were recruited during the past 21 years, and the diagnosis of ZS was based on clinical and biochemical characteristics. Plasma very long chain fatty acids (VLCFA) were analyzed using capillary gas chromatography. The estimated incidence of ZS was calculated using the HardyâWeinberg formula. Results: The estimated incidence of ZS is 1/15,898 in Tunisia. Age at diagnosis varied between 3 days and 18 months. Severe neurological syndrome, polymalformative features, and hepatodigestive signs were observed in 100%, 67.9%, and 32% of patients, respectively. Values for plasma C26:0 and C26:0/C22:0 and C24:0/C22:0 ratios were noticeably higher in ZS patients than in controls. Distributions of values were completely different for C26:0 (0.10â0.37 vs. 0.001â0.009), C26:0/C22:0 ratio (0.11â1.29 vs. 0.003â0.090), and C24:0/C22:0 ratio (1.03â3.18 vs. 0.4â0.90) in ZS patients versus controls, respectively. Conclusions: This study highlights the high incidence of ZS in Tunisia and the possibility of simple and reliable biochemical diagnosis, thus permitting early genetic counseling for families at risk. Key Words: gas chromatography, hypotonia, peroxisomal disorder, very long chain fatty acids, Zellweger syndrome

This study aims to assess vitamin A and E concentrations in the premature colostrum of lactating Tunisian women and to identify maternal characteristics that may affect these concentrations. Methods: Human colostrum was obtained from 105 mothers who gave birth prematurely in the Centre for Maternity and Neonatology of Tunis (Tunisia). Retinol and alpha-tocopherol were analyzed in the colostrum and in plasma by high-performance liquid chromatography. Results: Retinol and alpha-tocopherol concentrations were 57.5 ± 50.1 μg/dL and 1222 ± 772 μg/dL in the colostrum, respectively, and 51.7 ± 20.0 μg/dL and 1351 ± 772 μg/dL in plasma, respectively. Concentrations of each vitamin in the colostrum were positively correlated with their respective concentrations in plasma (r = 0.415, p = 0.001 for retinol and r = 0.392, p = 0.003 for alpha-tocopherol). In multivariate analysis, colostrum vitamin A was associated with plasma vitamin A and preeclampsia, while colostrum vitamin E was associated with plasma vitamin E, gestational age, and preeclampsia. Conclusion: In Tunisian women, colostrum vitamin A and E levels are close to the average values reported in the literature. The levels are too low to cover the needs of very low birth weight (VLBW) infants, particularly in women with plasma vitamin deficiencies, preeclampsia, or very premature delivery. Given the undeniable beneficial effects of human colostrum, whenever feasible, VLBW infants should be fed colostrum. Infant vitamin A and E requirements should be met by milk fortification or supplementation.

Preterm neonates are at high risk of vitamin deficiencies, which may expose them to increased morbidity and mortality. This study aimed to determine the prevalence and risk factors for vitamin A, E, and D deficiencies in Tunisian very low birth weight (VLBW) neonates. Methods: A total of 607 VLBW and 300 term neonates were included in the study. Plasma vitamins A and E were assessed by high performance liquid chromatography and vitamin D was assessed by radioimmunoassay. Results: Prevalence of vitamin A, E, and D deficiencies were dramatically elevated in VLBW neonates and were significantly higher than term neonates (75.9% vs. 63.3%; 71.3% vs. 55.5%; and 65.2% vs. 40.4%, respectively). In VLBW neonates, the prevalence of vitamin deficiencies was significantly higher in lower classes of gestational age and birth weight. Vitamin E deficiency was associated with pre-eclampsia [odds ratio (OR) (95% confidence interval, 95% CI), 1.56 (1.01–2.44); p

Introduction: Hyperglycemia is an exceptional manifestation of methylmalonic acidemia (MMA). We describe a patient with MMA in whom we observed a hyperglycemia which improved under treatment of the metabolic crisis., Case Report: A 14 month-old boy presented with an acute generalized dystonia and lethargy preceded by fever, vomiting and lethargy at the age of 13 months. Biological investigations showed a hyperglycemia, a lactic acidosis and a hyperammonemia. Urinary organic acid analysis showed accumulation of methylmalonic acid, tiglylglycine and methylcitrate leading to the diagnosis of MMA. The patient underwent symptomatic treatment with rapid improvement of general condition, consciousness and gradual normalization of biological parameters especially glycemia after 6 days without using insulinotherapy., Discussion: MMA is an autosomal recessive disorder caused by a deficiency of methylmalonyl-CoA mutase resulting in methylmalonic acid accumulation. Biochemically, the disorder is typically characterized by: metabolic acidosis, ketonemia or ketonuria, hyperammonemia, leukopenia, thrombocytopenia and anemia. Hypoglycemia is a frequent manifestation of MMA. Our patient presented a hyperglycemia, which is unusual in MMA, since we found only three patients reported with this association. Pathophysiology remains unknown. In reported cases, hyperglycemia was treated by insulin therapy and reducing glucose intravenous infusion, with fatal outcome. In our patient glycemia spontaneously normalized after treatment of the metabolic crisis., Conclusion: Hyperglycemia is an exceptional manifestation of MMA and could be a seriousness marker., (Copyright © 2011 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)