First cases in the Czech Republic of the Hallervorden-Spatz disease resulting from mutation in the pantothenate kinase 2 gene

Hallervorden-Spatz disease (HSD) was and is known as a rare disorder primarily characterized by progressive extrapyramidal dysfunction and dementia alongside optic nerve atrophy or retinal degeneration and pyramidal signs. The rate of occurence of HSD is thus far unknown. Progress in DNA diagnostics stirred up a nomenclature and from HSD, or, perhaps better put, the Hallervorden-Spatz syndrome, crystallized the pantothenate kinase-associated neurodegeneration (PKAN) as a clearly defined entity on the level of DNA. In this paper, we present our first results and experience in the diagnosis of PKAN in the Czech Republic and discuss questions related to differential diagnosis.     

Comparison of "high throughput" micromethods for determination of cytochrome P450 activities with classical methods using HPLC for product identification

Enzyme activities of the CYP enzymes (CYP3A4, CYP2C9 and CYP2A6) were determined using classical substrates (testosterone, diclofenac and coumarin, respectively) as well as with luminogenic or fluorogenic substrates in micromethod arrangement. The luciferin-based luminogenic substrates for CYP3A4 and CYP2C9 as well as coumarin in micromethod for assay of CYP2A6 activity gave results well comparable with the classical methods with determination of reaction products by the HPLC.     

The effect of feeding on specific soil algae on the cold-hardiness of two Antarctic micro-arthropods (Alaskozetes antarcticus and Cryptopygus antarcticus)

The effect of consuming terrestrial algae on the cold tolerance of two Antarctic micro-arthropods was examined. From the results of preferential feeding experiments, seven species of Antarctic terrestrial micro-algae were chosen and fed to two common, freeze-avoiding Antarctic micro-arthropods: the springtail Cryptopygus antarcticus (Collembola: Isotomidae), and the mite Alaskozetes antarcticus (Acari: Oribatida). Mites were very selective in their choice of food whereas the springtails were less discriminating. The ice nucleating activity of each species of alga was measured using an ice nucleator spectrometer and a differential scanning calorimeter. Pure cultures of individual species of algae had characteristic supercooling points ranging from ca. −5 to −18 °C. The effect of eating a particular alga on the supercooling point of individual micro-arthropods cultured at two different temperatures (0 and 10 °C) was examined. Neither species showed a preference for algae with low ice-nucleating activity and there was no clear correlation between the supercooling point of food material and that of the whole animal. However, feeding on certain algae such as Prasiola crispa, which contained the most active ice nucleators, decreased the cold tolerance of both species of arthropods. Accepted: 6 May 2000     

β-xylosidases and a nonspecific wall-bound β-glucosidase of the yeast cryptococcus albidus

Cryptococcus albidus grown on wood xylans possesses a soluble intracellular β-xylosidase (EC 3.2.1.37) as an additional constituent of the xylan-degrading enzyme system of this yeast. The enzyme attacks linear 1,4-β-xylooligosaccharides in an exo-fashion, liberating xylose from the non-reducing ends. The activity of the enzyme increases in the cells during growth on xylan and incubation with xylobiose or methyl β-D-xylopyranoside which are the best inducers of extracellular β-xylanase (EC 3.2.1.8). Various alkyl-, alkyl-1-thio- and aryl β-D-xylopyranosides were excellent of a different β-xylosidase of Cryptococcus albidus. This enzyme is localized outside the plasma membrane and is principally associated with cell walls. Unlike the soluble intracellular β-xylosidase, the wall-bound enzyme does not hydrolyze xylooligosaccharides. Evidence has been obtained that β-xylosidase activity in the cell walls is not due to the presence of a specific aryl β-xylosidase, but is exhibited by a nonspecific β-glucosidase (EC 3.2.1.21) inducible by β-D-xylopyranosides. The ratio of β-glucosidase and β-xylosidase activity in the cells and isolated cell walls from yeast induced by various β-xylopyranosides and β-glucopyranosides was very similar. Both wall-bound activities were inhibited in a similar pattern by inhibitors of β-glucosidases, 1,5-gluconolactone and nojirimycin. This bifunctional enzyme does not bear any relationship to the utilization of xylans in Cryptococcus albidus.     

Factors Affecting Growth of Tengmalm’s Owl (Aegolius funereus) Nestlings: Prey Abundance,Sex and Hatching Order

In altricial birds, energy supply during growth is a major predictor of the physical condition and survival prospects of fledglings. A number of experimental studies have shown that nestling body mass and wing length can vary with particular extrinsic factors, but between-year observational data on this topic are scarce. Based on a seven-year observational study in a central European Tengmalm’s owl population we examine the effect of year, brood size, hatching order, and sex on nestling body mass and wing length, as well as the effect of prey abundance on parameters of growth curve. We found that nestling body mass varied among years, and parameters of growth curve, i.e. growth rate and inflection point in particular, increased with increasing abundance of the owl’s main prey (Apodemus mice, Microtus voles), and pooled prey abundance (Apodemus mice, Microtus voles, and Sorex shrews). Furthermore, nestling body mass varied with hatching order and between sexes being larger for females and for the first-hatched brood mates. Brood size had no effect on nestling body mass. Simultaneously, we found no effect of year, brood size, hatching order, or sex on the wing length of nestlings. Our findings suggest that in this temperate owl population, nestling body mass is more sensitive to prey abundance than is wing length. The latter is probably more limited by the physiology of the species.     

Melatonin administered during the fetal stage affects circadian clock in the suprachiasmatic nucleus but not in the liver

The mammalian circadian system develops gradually during ontogenesis, and after birth, the system is already set to a phase of the mothers. The role of maternal melatonin in the entrainment of fetal circadian clocks has been suggested, but direct evidence is lacking. In our study, intact or pinealectomized pregnant rats were exposed to constant light (LL) throughout pregnancy to suppress the endogenous melatonin and behavioral rhythms. During the last 5 days of gestation, the rats were injected with melatonin or vehicle or were left untreated. After delivery, daily expression profiles of c‐fos and Avp in the suprachiasmatic nuclei (SCN), and Per1, Per2, Rev‐erbα, and Bmal1 in the liver were measured in 1‐day‐old pups. Due to the LL exposure, no gene expression rhythms were detected in the SCN of untreated pregnant rats or in the SCN and liver of the pups. The administration of melatonin to pregnant rats entrained the pups' gene expression profiles in the SCN, but not in the liver. Melatonin did not affect the maternal behavior during pregnancy. Vehicle injections also synchronized the gene expression in the SCN but not in the liver. Melatonin and vehicle entrained the gene expression profiles to different phases, demonstrating that the effect of melatonin was apparently not due to the treatment procedure per se. The data demonstrate that in pregnant rats with suppressed endogenous melatonin levels, pharmacological doses of melatonin affect the fetal clock in the SCN but not in the liver. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 75: 131–144, 2015