Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na
Ograniczanie wyników
Czasopisma help
Lata help
Autorzy help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 75

Liczba wyników na stronie
first rewind previous Strona / 4 next fast forward last
Wyniki wyszukiwania
w słowach kluczowych:  histochemistry
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 4 next fast forward last
The target of the study was to examine histochemically in vivo the activity of prostaglandin synthetase in Trichinella spiralis larvae in stages of their migration, settlement and encapsulation in the host’s tissues. It was proved that prostaglandins may play certain role in producing circumlarval capsules.
Histochemical studies on the activity of some neuropeptides (PGP, CT, NPY, SP and βE) and enzymes (AP, A1P, SDH and MAO) were performed on guinea pig parathyroid glands after injections of histamine, histamine receptor blockers and muscarinic receptor blocker. Under conditions of histamine shock, the immunoreactivity of CT and the reactivity of SDH and MAO were found to decrease together with an increase in the activity of βE and AP. The reactions for SP, NPY, PGP and A1P did not change in any of the groups.
The accumulation of neutral lipids in the cells predetermined to evolve into the cyst cavity lining in Hymenolepis diminuta cysticercoids is presented. The differentiation of these cells from the mesenchyma cells and the accompanying systhesis of lipids began in very young, blastula-shaped larvae. Both the number of the cells and the amount of their lipids increased gradually during further development of the parasites. In the pre-encystment stage of the cysticercoids the cells concentrated around the cavity of the prospective cyst. Following encystment, the scolex and the inverted neck became surrounded by a compact mass of the cells, which started using the stored lipids as a source of energy indispensable for the formation of the cyst tissues and of the definitive multilayer lining of the cyst cavity. No neutral lipids were detected in the mature 23-day-old cysticercoids as well as in the experimentally excysted scoleces. Beside a low level of uniformly distributed phospholipids apparently associated with cell membranes, no local accumulations of these substances were observed at any step of the development of the larvae. The utilization of neutral lipids proves both the presence of a lipase-type enzyme(s) and an operative β-oxidation pathway in the cells of the cysticercoids, the latter feature being highly indicative of oxidative metabolism of these larvae.
The distribution of acetylcholinesterase (AChE) in oncospheres and developing cysticercoids of Hymenolepis diminuta was examined. The enzyme was localized in the nervous system and in some non-nerve cells of these larvae. In oncospheres AChE was detected in hook muscles and in the binucleated medullar center that is known to enclose two neurons. At early developmental stages of the cysticercoids the enzyme was localized in the post-oncospheral hook muscles and in subtegumental muscle fibers of the cercomer. At medium and late stages of development the activity of AChE was detected in the developing nervous system and in two and, subsequently, in four populations of cells, which gradually spread over the whole internal wall of the cyst, thus forming a thin multilayer AChE-positive lining of the cyst cavity. Following withdrawal of the scolex the lining separates the parenchyma of the turned neck from the cyst tissues and remains AChE-positive during the whole life of the parasite, i.e. up to the death of the infected host. The role played by non-neural AChE associated with the cyst cavity lining is unknown, but seems to regulate both the transport of nutrients and minerals into the scolex and waste substances in the opposite direction.
first rewind previous Strona / 4 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.