Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 33

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  molecule
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Quantitative estimation of the structure anticancer activity relationship in a series of macrocyclic Schiff bases of 2,6-bis(formylaryloxymethyl)pyridines was carried out by the topological approach. Correlation equations describing the relationship between the anticancer activity and structural parameters of the molecules studied and descriptors characterizing their structure were obtained on the basis of in vitro screening data. The influence of structure of the investigated substances as reflected by the parameters studied on the anticancer activity, was established.
A bridged peptide with the sequence: H-Thr-Pro-Gln-Arg-Gly-Asp-Val-y-Abu-Asn- Asp-Gln-Glu-Glu-Thr-Thr-Gly-Val-Val-Ser-Thr-Pro-Leu-Ile-Arg-Asn-Gly-OH was de­signed to mimic the discontinuous epitope of the HLA-DQ molecule that might interact with CD4. The bridged peptide revealed distinct suppressory effect in the humoral im­mune response. This result supports our suggestion that the 164-172 region of the HLA-DQ molecule may enhance its interactions with coreceptors, possibly with CD4.
The laminin receptor precursor (LRP) has been the center of intense controversy and interest for over a decade. Chief among these controversies is the putative multifunctional aspect of this molecule: as a ribosomal-associated protein (p40) and/or as the precursor for the 67kDa high-affinity laminin receptor (67LR), neither of which have been definitively established. Other controversies include the presence of more than one 67kDa laminin receptor protein. However, interest in the molecule is sustained because of its vital function in the cell as a component of the translational machinery and due to its constant up-regulation in cancer cells with the invasive and metastatic phenotype and in association with poor prognosis. Recently, while studying the autoimmunogenicity of a species conserved 37-44 kDa oncofetal antigen (37kDa OFA), the authors of this paper, using amino acid sequencing of isolated OFA-peptides, cDNA cloning and sequencing and antigens-antibodies cross reactivity as well as antigens-T cell recognition reactions, identified the 37kDa OFA as precursor or immature laminin receptor protein.
Computer modelling related to the real dimensions of both the whole filament and the myosin molecule subfragments has revealed two alternative modes for myosin molecule packing which lead to the head disposition similar to that observed by EM on the surface of the cross-bridge zone of the relaxed vertebrate skeletal muscle thick fil­aments. One of the modes has been known for three decades and is usually incorpo­rated into the so-called three-stranded model. The new mode differs from the former one in two aspects: (1) myosin heads are grouped into asymmetrical cross-bridge crowns instead of symmetrical ones; (2) not the whole myosin tail, but only a 43-nm C-terminus of each of them is straightened and near-parallel to the filament axis, the rest of the tail is twisted. Concurrent exploration of these alternative modes has re­vealed their influence on the filament features. The parameter values for the filament models as well as for the building units depicting the myosin molecule subfragments are verified by experimental data found in the literature. On the basis of the new mode for myosin molecule packing a complete bipolar structure of the thick filament is cre­ated.
Recent literature on the evolution and interrelationships of the Caryophyllidea based on molecular and morphological criteria is reviewed. Molecular analyses with SSU rDNA, LSU rDNA and ef-1 alpha reaffirms the basal or near basal position of these nonozoic cestodes. Major emphasis is on an evaluation of the scoring in morphological character matrices used in cladistic studies. Suggested changes to present scoring are: uterus is dorsal; scolex is afossate, fossate or difossate with little support for monofossate; ciliated coracidium is absent; vitellaria are circum-cortical and circum-medullary; testes are cortical and medullary; metacercoid stage is absent; and the spermatozoan lacks a crested body, flagellar rotation and proximodistal fusion. Of the 41 recognized genera of the Caryophyllidea, 59% have an afossate scolex and the remainders are fossate. The use of a new character, “nuclear vacuole” in the nucleus of mature vitellocytes, is suggested. To aid in identifying cestode body types in an evolutionary context, they are designated as monopleuroid, polypleuroid and strobila. Tabulated differences between the monozoic Caryophyllidea and polyzoic eucestodes suggest that the two groups may warrant separate taxonomic status. The question of whether or not the monozoic state is primary or secondarily derived is not resolved. Using the life cycle characterstics of the Pseudophyllidea and of Archigetes as models, it is hypothesized that progenesis may have played a major role in the evolution of the Caryophyllidea. If the role of progenesis can be substantiated through total evidence incorporating cytohistological data, then the monozoic condition becomes coincidental and the hypothesis is not supported that the Caryophyllidea are ancestral and preceded polyzoic eucestodes.
The basic form of pollution is characterized by a microscopic size and solid state and it is called particulates or particulate matter. Unfortunately, these forms undergo a variety of transformations, which consequently can sometimes be easily modified and even cause an increase in their toxicity. This work was devoted to join the composition of various materials being residues after different combustion processes with the distribution of elements and molecules within studied surfaces. The content of chosen elements was determined using ICP-MS and ICP-OES methods. Elemental and/or molecular distribution was studied using surface sensitive techniques, SEM-EDS and ToF-SIMS. The obtained results revealed that the composition and morphology of particles are strongly influenced by the type of material and combustion conditions.
Syntaxin 8 has been shown to form the SNARE complex with syntaxin 7, vti1b and endobrevin. These have been shown to function as the machinery for the homotypic fusion of late endosomes. Recently, we showed that syntaxins 7 and 8 cycle through the plasma membrane, and that the di-leucine-based motifs in the cytoplasmic domain of syntaxins 7 and 8 respectively function in their endocytic and exocytic processes. However, we could not elucidate the mechanism by which syntaxin 8 cycles through the plasma membrane. In this study, we constructed several different syntaxin 8 molecules by mutating putative di-leucine-based motifs, and analyzed their intracellular localization and trafficking. We found a di-leucine-based motif in the cytoplasmic domain of syntaxin 8. It is similar to that of syntaxin 7, and functions in its endocytosis. These results suggest that in the cytoplasmic domain, syntaxin 8 has two functionally distinct di-leucine-based motifs that act independently in its endocytic and exocytic processes. This is the first report on two di-leucine-based motifs in the same molecule acting independently in distinct transport pathways.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.