Analysis of expression profiles of genes involved in F(o)F(1)-ATP synthase biogenesis during perinatal development in rat liver and skeletal muscle.

During the process of intra-uterine mammalian fetal development, the oxygen supply in growing fetus is low. A rapid switch from glycolysis-based metabolism to oxidative phosphorylation (OXPHOS) must proceed during early postnatal adaptation to extra-uterine conditions. Mitochondrial biogenesis and mammalian mitochondrial F(o)F(1)-ATP synthase assembly (complex V, EC 3.6.3.14, ATPase) are complex processes regulated by multiple transcription regulators and assembly factors. Using RNA expression analysis of rat liver and skeletal tissue (Rattus norvegicus, Berkenhout, 1769), we describe the expression profiles of 20 genes involved in mitochondrial maturation and ATP synthase biogenesis in detail between the 16th and 22nd day of gestation and the first 4 days of life. We observed that the most important expression shift occurred in the liver between the 20th and 22nd day of gestation, indicating that the fetus prepares for birth about two days before parturition. The detailed mechanism regulating the perinatal adaptation process is not yet known. Deeper insights in perinatal physiological development will help to assess mitochondrial dysfunction in the broader context of cell metabolism in preterm newborns or neonates with poor adaptation to extra-uterine life.

Analysis of Mitochondrial Network Morphology in Cultured Myoblasts from Patients with Mitochondrial Disorders.

Mitochondrial morphology was studied in cultivated myoblasts obtained from patients with mitochondrial disorders, including CPEO, MELAS and TMEM70 deficiency. Mitochondrial networks and ultrastructure were visualized by fluorescence microscopy and transmission electron microscopy, respectively. A heterogeneous picture of abnormally sized and shaped mitochondria with fragmentation, shortening, and aberrant cristae, lower density of mitochondria and an increased number of "megamitochondria" were found in patient myoblasts. Morphometric Fiji analyses revealed different mitochondrial network properties in myoblasts from patients and controls. The small number of cultivated myoblasts required for semiautomatic morphometric image analysis makes this tool useful for estimating mitochondrial disturbances in patients with mitochondrial disorders.

[Mitochondrial metabolism in mammalian spermatozoa--a minireview]. / Mitochondriální metabolismus v savcích spermiích--minireview.

Mitochondria are organelles producing macroergic compounds in basically all eukaryotic cells except mature erythrocytes. Mitochondria play an important role even in mammalian spermatozoa, in which mitochondrial ATP biosynthesis covers energetic demands connected with sperm movement (motility), maturation (including capacitation) and oocyte fertilisation. Mitochondrial localization and the existence of some specific mitochondrial-protein isoforms point at its indispensable role in fertility maintenance. Mitochondrial disorders are often manifested in tissues with high-energy demands (myopathy, neuropathy, cardiomyopathy), but mitochondrial dysfunction can be often detected also in other peripheral tissues and cells like spermatozoa. The main goal of this minireview is to summarize the most important findings about mitochondria producing cellular ATP supply and to present spermatozoa as a suitable and valuable biological material, which might be, despite of its uniqueness, a very useful material in clinical diagnostics of certain disorders including mitochondrial or neurodegenerative disorders.

The problems of proteinuria measurement in urine with presence of Bence Jones protein.

OBJECTIVES: Protein concentration measurement in the urine can be problematic in the presence of Bence Jones protein. We have carried out an external quality control assessment with the participation of 79 clinical biochemistry laboratories from the Czech Republic and Slovakia. DESIGN AND METHODS: The laboratories received a reference urine sample obtained from a patient with multiple myeloma and lambda free light chain proteinuria and were asked to type the paraprotein using immunofixation and to measure total urinary protein using their established method, most commonly turbidimetry, pyrogallol red assay, and biuret assay. RESULTS: There was a very wide inter-laboratory variability in the protein concentration readouts with up to three-fold difference in some cases. High-resolution two-dimensional electrophoresis and linear mass spectrometry showed that a high proportion of the urinary paraprotein was composed of lambda light chain fragments with molecular weight of 12kDa. CONCLUSIONS: Our results highlight the challenges of reliable and reproducible measurement of urinary protein concentration in the presence of Bence Jones protein.

[Subclinical hypothyroidism with emphasis on the cardiovascular system]. / Subklinická hypotyreóza se zamerením na kardiovaskulární systém.

Subclinical hypothyroidism is comparatively frequent disorder with incidence between 3 to 7% in the general population; in females over 60 it can exceed 10%. There is no unequivocal view on the clinical significance of the syndrome; however, it may correspond with increased risk of atherosclerosis and its complications. Especially in elderly women, screening for subclinical hypothyroidism is recommended with possible hormone replacement according to given criteria. Decision about the therapy of subclinical hypothyroidism should be done together with cardiologist, psychiatrist or neurologist in order to correct possible clinical impacts and prevent further manifestations.