Progress in Histochemistry and Cytochemistry最新文献

For the purpose of studying the aging changes of macromolecular synthesis in animal cells, we studied many groups of aging mice during development and aging from fetal day 19 to postnatal newborn, juvenile, young adults, aged and senescent adults up to 12 and month 24 (2 years). They were injected with ³H-thymidine, ³H-uridine or ³H-leucine, precursors for DNA, RNA and proteins, as well as ³H-glucose, ³H-glucosamine, ³⁵S-sulfuric acid, or ³H-glycerol for glucide and lipid precursors, respectively, then sacrificed and the liver tissues were taken out, fixed and processed for light and electron microscopic radioautography. On many radioautograms the localization of silver grains demonstrating DNA, RNA and proteins in hepatocytes in respective aging groups were analyzed qualitatively. The number of silver grains and the number of cell organelles in each cell of each animal in respective aging groups were analyzed quantitatively in relation to the aging of individual animals. The results revealed that the localization of respective precursors as well as the number of silver grains in cell nuclei, cell organelles, changed with the aging of animals. The numbers of labeled nuclei and cell organelles, as well as the numbers of silver grains in nuclei and cell organelles changed due to aging of individual animals. The number of mitochondria, the number of labeled mitochondria and the mitochondrial labeling index labeled with silver grains were counted in each hepatocyte. It was demonstrated that the numbers of mitochondria, the numbers of labeled mitochondria and the labeling indices showing DNA, RNA and protein synthesis at various ages from embryonic day 19 to postnatal newborn day 1, 3, 9, 14, adult month 1, 2 and 6, reaching the maxima, then decreased to senile year 1 to 2, indicating the aging changes. The results indicated that mitochondria in hepatocytes synthesized nucleic acids and proteins independently from the nuclei, but their synthetic activities were affected from the aging of the individual animals.

There is a rich knowledge of the enteric nervous system (ENS), especially the neurochemical and neurophysiological properties of enteric neurons and how they communicate in neural circuits underlying intestinal reflexes. The major pathways of excitatory transmission within the ENS are mediated by cholinergic and tachykinergic transmission, with transmitters Acetylcholine (ACh) and Tachykinins (TK), respectively, producing excitatory potentials in post-synaptic effectors. This review focuses on the cholinergic pathways of the ENS. The cholinergic circuitry of the ENS is extensive and mediates motility (muscular) and secretory (mucosal) reflexes, in addition to intrinsic sensory and vascular reflexes. The capacity of ACh to mediate multiple physiologically significant intestinal reflexes is largely due to having multiple sites of neuronal and non-neuronal release and reception within the intestine. This review will concentrate on one of two classes of ACh receptors, Muscarinic receptors (mAChr), in particular their location and function in mediating synaptic transmission within enteric circuits underlying intestinal reflexes.

Quantitative colocalization analysis is an advanced digital imaging tool to characterize the spatial expression of molecules of interest in immunofluorescence images obtained using confocal microscopes. It began from simple pixel counting and, with introduction of specialized algorithms, transformed into a powerful image analyzing technique capable of identifying the exact locations of various molecules in tissues and cells and describing their subtle changes in dynamics. Applications of quantitative colocalization in the field of neuroscience proved to be particularly informative by helping to obtain observations not otherwise achievable using other techniques. In this article, we review the background and applicability of quantitative colocalization with special focus on neuroscience research.

Endocytosis is essential for eukaryotic cell survival and has been well characterized in mammal and yeast cells. Among protozoa it is also important for evading from host immune defenses and to support intense proliferation characteristic of some life cycle stages. Here we focused on the contribution of morphological and cytochemical studies to the understanding of endocytosis in Trichomonas, Giardia, Entamoeba, Plasmodium, and trypanosomatids, mainly Trypanosoma cruzi, and also Trypanosoma brucei and Leishmania.

The antiapoptotic, antioxidant, proliferative, and angiogenic effects of metallothionein (MT)-I+II has resulted in increased focus on their role in oncogenesis, tumor progression, therapy response, and patient prognosis. Studies have reported increased expression of MT-I+II mRNA and protein in various human cancers; such as breast, kidney, lung, nasopharynx, ovary, prostate, salivary gland, testes, urinary bladder, cervical, endometrial, skin carcinoma, melanoma, acute lymphoblastic leukemia (ALL), and pancreatic cancers, where MT-I+II expression is sometimes correlated to higher tumor grade/stage, chemotherapy/radiation resistance, and poor prognosis. However, MT-I+II are downregulated in other types of tumors (e.g. hepatocellular, gastric, colorectal, central nervous system (CNS), and thyroid cancers) where MT-I+II is either inversely correlated or unrelated to mortality. Large discrepancies exist between different tumor types, and no distinct and reliable association exists between MT-I+II expression in tumor tissues and prognosis and therapy resistance. Furthermore, a parallel has been drawn between MT-I+II expression as a potential marker for prognosis, and MT-I+II's role as oncogenic factors, without any direct evidence supporting such a parallel. This review aims at discussing the role of MT-I+II both as a prognostic marker for survival and therapy response, as well as for the hypothesized role of MT-I+II as causal oncogenes.