Publications by authors named "Bisera Atanasova"

Gestational diabetes mellitus (GDM) is considered the most common metabolic disorder of the pregnancy period. It is characterized by pancreatic beta-cell dysfunction in the setting of chronic insulin resistance. Zinc is a nutrient involved in numerous metabolic processes and shows a relationship with glycometabolic disorders and GDM.

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Background: Copper (Cu) is a physiologically important trace element during pregnancy. The study aim is to assess the altered level of serum Cu and its association with some metabolic indexes in Gestational Diabetes Mellitus (GDM).

Methods: A total of 108 pregnant women (aged 18 - 40, second trimester) are included in the study and divided into two groups (GDM n = 54; pregnant with normal glucose tolerance (NGT), n = 54) after performing a 2-hour 75-g oral glucose tolerance test (OGTT).

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Background: The dynamics of essential metals such as Copper (Cu) and Zinc (Zn) may be associated with the novel coronavirus disease 2019 (COVID-19) that has spread across the globe.

Objectives: The aim of this study is to investigate the relationship between serum levels of Cu and Zn, as well as the Cu:Zn ratio in the acute phase of COVID-19 along with the assessment of their connection to other laboratory parameters (hematological, biochemical, hemostatic).

Methods: Serum levels of Cu and Zn were measured by atomic absorption spectrometry in 75 patients in the acute COVID-19 phase and were compared with those of 22 COVID-19 patients evaluated three months after the acute phase of the disease ('non-acute' group) and with those of 68 healthy individuals.

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Background: Hepcidin is a 25-aminoacid cysteine-rich iron regulating peptide. Hepcidin quantification in human serum provides new insights for the pathogenesis of disorders of iron homeostasis. This study describes an ELISA immunoassay for hepcidin quantification in human serum and reference ranges for Bulgarian population.

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Background: The first step in iron absorption requires the reduction of ferric iron to ferrous iron, a change that is catalyzed by duodenal ferric reductase. Iron deficiency is associated with high iron absorption, high ferric reductase activity, and high duodenal ascorbate concentrations in experimental animals, but it is not known whether a relation between reductase and ascorbate is evident in humans.

Objective: The objective of the study was to assess the relation between ferric reductase activity in human duodenal biopsy specimens and ascorbate concentrations in iron-replete and iron-deficient subjects.

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Ascorbate has long been thought to play an important role in intestinal iron absorption. The recent identification of a possible ascorbate-dependent duodenal ferric reductase suggests a role for intracellular ascorbate in the control of iron absorption. We set out to determine whether duodenal ascorbate concentrations are altered by treatments known to alter the rate of iron absorption and whether ascorbate levels affect duodenal reductase activity.

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