Morphological changes in the human thyroid gland cultivated in continual flow system

In the present pilot study, the human thyroid gland tissue was cultivated under continuous culture conditions in the culture chambers of the ACUSYST-S system to determine morphological changes as well as the secretion of thyreoglobulin (Tgl) and thyroid hormones. After 24 hours of cultivation the follicular structure of the tissue was preserved in peripheral parts only, and there were regressive changes in the epithelium center. After 72 hours the regressive changes appeared in isolated follicles only; the size of the follicles increased, the height of the follicular epithelium decreased and there were macrophages present with phagocytized cell debris. After 144 hours disintegration of epithelia took place in the centre, while at the periphery the original follicles survived and very tiny new follicles formed, consisting of only 6 to 8 cells each and surrounding in section the homogeneous colloid. The parenchyma picture suggests a possibility of functional regeneration as an expression of adaptation to the conditions newly arisen during cultivation in a culture chamber. There was no significant influencing of the thyroid hormone secretion during cultivation. On the other hand, the Tgl secretion decreased throughout cultivation.     

Energy flows in rural China

A quantitative analysis of major rural energy flows in the People's Republic of China shows that the nation 's countryside still depends predominantly on solar radiation transformed by green plants through photosynthesis into food, feed, fuel, and raw materials. Although a large-scale modernization effort currently under way aims to greatly increase the consumption of fossil fuels and electricity, it is argued that the country should not completely abandon its renewable rural energetics.     

Chromosome-wide characterization of meiotic noncrossovers (gene conversions) in mouse hybrids

During meiosis, the recombination-initiating DNA double-strand breaks (DSBs) are repaired by crossovers or noncrossovers (gene conversions). While crossovers are easily detectable, noncrossover identification is hampered by the small size of their converted tracts and the necessity of sequence polymorphism. We report identification and characterization of a mouse chromosome-wide set of noncrossovers by next-generation sequencing of 10 mouse intersubspecific chromosome substitution strains. Based on 94 identified noncrossovers, we determined the mean length of a conversion tract to be 32 bp. The spatial chromosome-wide distribution of noncrossovers and crossovers significantly differed, although both sets overlapped the known hotspots of PRDM9-directed histone methylation and DNA DSBs, thus supporting their origin in the standard DSB repair pathway. A significant deficit of noncrossovers descending from asymmetric DSBs proved their proposed adverse effect on meiotic recombination and pointed to sister chromatids as an alternative template for their repair. The finding has implications for the molecular mechanism of hybrid sterility in mice from crosses between closely related Mus musculus musculus and Mus musculus domesticus subspecies.     

Markers of Chlamydia pneumoniae and human cytomegalovirus infection in patients with chronic peripheral vascular disease and their relation to inflammation, endothelial dysfunction and changes in lipid metabolism

Our aim was to detect markers of Chlamydia pneumoniae (CPN) and human cytomegalovirus (HCMV) infection in patients with peripheral vascular occlusive disease and to follow markers of inflammation, endothelial dysfunction and lipid metabolism alteration in patients with active infection. CPN genome was detected in 9 (47.4 %) patients by at least one PCR method. Serological markers of acute CPN infection were found in 5 (26.3 %) subjects; each of them showed also positivity in at least one of the PCR methods. HCMV DNA were detected in 2 (10.5 %) patients; HCMV-specific antibodies were detected in 14 (73.7 %) subjects, however only in IgG subclass. Subjects with HCMV PCR positivity thus showed no serological markers of active HCMV infection. Laboratory findings of acute CPN infection were associated with increased plasma levels of Lp(a), triacylglycerols, atherogenic index of plasma and E-selectin (p < 0.05). No significant differences were found in the other markers, including plasma levels of total cholesterol, ferritin, homocysteine, oxidized LDL, IL-6, IL-8, IL-18, TNF-α, soluble forms of VCAM-1 and ICAM-1, von Willebrand factor, C-reactive protein, and plasma nitrites & nitrates. Frequent presence of chlamydial DNA in atheromatous plaques from patients with peripheral vascular disease was confirmed. HCMV DNA was detected only sporadically and with positivity in anamnestic anti-HCMV antibodies (IgG) only, indicating a rare presence of latent virus rather than active replication. Patients with laboratory markers of acute CPN infection exhibited more pronounced alterations in lipid metabolism and endothelial dysfunction.     

Myotube-like structures in cultures of rat liver cells

Branching and budding myotube-like structures developed in primary cultures of rat liver cells and in the JH1 cell line derived from them. Elongated uninuclear cells aligned in chains and fused into multinuclear tubes of varying length and thickness. The tubes contained thick and thin filaments running in all directions. The filaments were occasionally linked with M lines and formed incomplete hexagonal patterns resembling those of skeletal muscle myofilaments, but a regular arrangement of the filaments and organelles was lacking. Cross-striation and contractions were never observed. Both uninuclear cells and multinuclear tubes contained numerous lysosomes, myelin figures and lamellated bodies as well as electronlucent or content-filled vacuoles and cisternae of variable size, sometimes reminding the sarcoplasmic reticulum in early stages of its development. Endocytotic caveolae and vesicles were present in all elements. These features together with interdigitated cell processes and specialized cell contacts suggested a possible relationship of the cells to the reticuloendothelial system.     

Economical Parallel Oligonucleotide and Peptide Synthesizer – Pet Oligator

We have developed a small benchtop oligonucleotide synthesizer which allows the scientist to prepare, rapidly and economically, up to 24 oligonucleotides in one batch. We have shown that this instrument can be used for peptide synthesis, as well. The instrument is based on the centrifugation method for solid–liquid separation. Dedicated to the memory of Prof. Bruce Merrifield, who was the inspiration behind all of our efforts in building automatic synthesizers.     

The process of continuous production and isolation of coproporphyrin

Summary The production of coproporphyrin from glucose and urea has been achieved by semi-aerobic culture ofSaccharomyces cerevisiae. The cells were entrapped in alginate gel and packed into a column reactor for continuous long-term process. The porphyrins were isolated and simultaneously concentrated from the effluent by liquid-solid phase extraction, purified by liquid chromatography and finally crystallized. Using the process described the final product of high purity was obtained.