Changes in fluorescence emission spectra (293 and 77 K) of phycobilisomes from Nostoc flagelUforme during dissociation in phosphate buffer of various molarity were studied. There were three bands in 77 K fluorescence emission spectra of partly dissociated phycobilisomes: F648, F666 and F686, characteristic of C-phycocyanin (C-PC), allophycocyanin (APC) and allophycocyanin-B (APC-B), respectively. In severely dissociated phycobilisomes, the F666 band was veiy weak, which indicated that linkage between C-PC and APC was severely dissociated, most of the energy trapped by C-PC could not be transferred to APC, but some of it could be transferred directly to APC-B. The phycobiliproteins in these phycobilisomes constitute an energy transfer chain: PEC^C;PC-»APC-»AP^-B. A new model of phycobilisome structure is suggested, in which some C-PC contact directly with APC and others contact with APC-B.
The kinetics of bacteriochlorophyll fluorescence in intact cells of the purple nonsulfur bacterium Rhodobacter sphaeroides were measured under continuous and pulsed actinic laser diode (808 nm wavelength and maximum 2 W light power) illumination on the micro- and millisecond timescale. The fluorescence induction curve was interpreted in terms of a combination of photochemical and triplet fluorescence quenchers and was demonstrated to be a reflection of redox changes and electron carrier dynamics. By adjustment of the conditions of single and multiple turnovers of the reaction center, we obtained 11 ms-1 and 120 μs-1 for the rate constants of cytochrome c23+ detachment and cyclic electron flow, respectively. The effects of cytochrome c2 deletion and chemical treatments of the bacteria and the advantages of the fluorescence induction study on the operation of the electron transport chain in vivo were discussed., G. Sipka, M. Kis, J. L. Smart, P. Maróti., and Obsahuje bibliografické odkazy
Významným fyziologickým parametrem živých buněk i řady jejich organel je membránový potenciál. K jeho sledování se často používá fluorescenčních sond, které se akumulují uvnitř buněk až do vyrovnání jejich intra- a extracelulárních elektrochemických potenciálů. Obsahem tohoto článku je přehled optických metod sloužících k tomuto účelu, jenž zahrnuje spektrofluometrii, proudovou cytometrii a konfokální mikroskopii a je prezentován jako průřez aktivitami biofyzikálního oddělení Fyzikálního ústavu UK na Matematicko-fyzikální fakultě UK., Jaromír Plášek, Dana Gášková., and Obsahuje seznam literatury
Patients treated for knee disorders were included in this study. They were examined clinically (Lequesne and Tegner scores) and by standard X-ray investigation. Patients underwent a surgical procedure, either arthroscopy or knee replacement. At the initial phase of surgery, a sample of cartilage was taken for laboratory examination. Progression of the disorder and the clinical examination was correlated with the actual state of the cartilage using a novel fluorescence approach. The intrinsic fluorescence of cartilages was shown as a suitable and sensitive method for detection of the actual state of cartilages because the correlation with X-ray examination and clinical status was found. Intrinsic fluorescence properties of cartilages from patients with chondropathy and osteoarthritis were described and found to be age-dependent. We also observed a higher concentration of advanced glycation end products due to inflammatory and/or degenerative processes in the cartilage. In addition, acute pathological changes due to diseases such as meniscal lesions or anterior cruciate ligament rupture caused a significant increase of formation of advanced glycation end products even in the group of young patients. In fact, such an observation could be crucial and important for the detection of knee conditions suspected of early meniscal and/or ACL lesions especially among young patients., M. Handl, E. Filová, M. Kubala, Z. Lánský, L. Koláčná, J. Vorlíček, T. Trč, M. Pach, E. Amler., and Obsahuje bibliografii a bibliografické odkazy
Aluminofluoride complexes (AlFx) form spontaneously in aqueous solutions containing fluoride and traces of aluminum ions and appear to act as phosphate analogs. These complexes have become widely utilized in laboratory investigations of various guanine nucleotide-binding proteins. Reflecting on many laboratory studies, a new mechanism of fluoride and aluminum action on the cellular level is being suggested. The long-term synergistic effects of these ions in living environment and their hidden danger for human health are not yet fully recognized., A. Strunecká, O. Strunecký, J. Patočka., and Obsahuje bibliografii
Rutinní testování prostatického specifického antigenu v některých částech světa vedlo k významné migraci stadia karcinomu prostaty v době diagnózy, což má často za následek zbytečnou diagnostiku (over-diagnosis) a zbytečnou léčbu (over-treatment) onemocnění. Při volbě radikálních definitivních možností léčby jako radikální prostatektomie a radioterapie jsou potom pacienti vystaveni nežádoucím účinkům souvisejícím s léčbou. Koncepce „aktivního sledování s indikací odložené intervence v případě potřeby“ získala popularitu jako možné řešení zbytečné léčby onemocnění, přestože tento přístup má svá omezení. Pro léčbu některých typů lokalizovaného karcinomu prostaty se tak nabízí jako vhodná alternativa fokální terapie. Pokrok v zobrazovacích technologiích a skutečnost, že jsme schopni bezpečně a účinně aplikovat energii potřebnou pro ablaci ložiska lokalizovaného karcinomu prostaty, umožnily rychlejší přijetí této formy léčby. Ačkoli v současné době nejsou k dispozici žádné údaje první úrovně, probíhá několik studií, které se pokoušejí definovat roli fokální terapie. Kryoterapie a fokusovaný ultrazvuk o vysoké intenzitě jsou zavedené modality užívané pro ablaci celé prostatické žlázy. V našem článku hodnotíme různé techniky fokální léčby lokalizovaného karcinomu prostaty a indikace pro tuto léčbu spolu s prvními publikovanými výsledky. Klíčová slova: karcinom prostaty fokální terapie kryoablace fokusovaný ultrazvuk o vysoké intenzitě intersticiální laserová terapie fotodynamická terapie ireverzibilní elektroporace a fokální brachyterapie, The ubiquity of prostate specific antigen testing in certain parts of the world has led to significant stage migration of prostate cancer at presentation, apparently resulting in over-diagnosis and over-treatment. With radical definitive therapies such as radical prostatectomy and radiotherapy, patients have to endure treatment-related adverse effects. “Active surveillance with delayed intervention if necessary”, has gained popularity as a possible solution for the over-treatment problem, although this approach also has inherent limitations. Focal therapy is emerging as a viable management option for certain localized prostate cancers. Advancement in imaging technology coupled with the ability to safely and effectively deliver energy to ablate foci of localized prostate cancer has accelerated acceptance of this form of management. Level one evidence is still lacking, although a number of trials are now underway to define the role of focal therapy. Cryotherapy and high intensity focused ultrasound have an established track record as energy sources for whole gland prostate ablation. In this article we review the indications and technique of focal treatment for localized prostate cancer, as well as early published results using these two technologies. Key Words: prostate cancer focal therapy cryoablation high intensity focused ultrasound interstitial laser photodynamic therapy irreversible electroporation and focal brachytherapy, and Siddiqui K. M., Billia M., Izawa J., Chin J. L.