Search results for "Secretory"
showing 10 items of 150 documents
Secretory breast carcinoma with metastatic sentinel lymph node
2006
Abstract Background Secretory mammary carcinoma is a rare breast neoplasia originally described in children but sometimes also found in adults. It presents a more favourable outcome than more common histological types of breast carcinoma; published literature in fact reports only a few cases with axillary lymph node metastases and only four cases with distant metastases. Clinical presentation In this paper we report a rare case of secretory breast carcinoma with axillary lymph node metastases in a 33-year-old woman. To our knowledge, this is the first case of secretory carcinoma involving biopsy of the sentinel lymph node and investigation of the e-cadherin expression. We found positivity f…
Vascular Senescence: A Potential Bridge Between Physiological Aging and Neurogenic Decline
2021
The adult mammalian brain contains distinct neurogenic niches harboring populations of neural stem cells (NSCs) with the capacity to sustain the generation of specific subtypes of neurons during the lifetime. However, their ability to produce new progeny declines with age. The microenvironment of these specialized niches provides multiple cellular and molecular signals that condition NSC behavior and potential. Among the different niche components, vasculature has gained increasing interest over the years due to its undeniable role in NSC regulation and its therapeutic potential for neurogenesis enhancement. NSCs are uniquely positioned to receive both locally secreted factors and adhesion-…
Intraepidermal formation of Merkel cells in xenografts of human fetal skin.
1990
An experimental transplantation model using human fetal skin was applied to approach the question of the embryologic origin of human Merkel cells. Palmar and plantar skin from five fetuses, between 8 and 11 weeks of estimated gestational age (EGA), was xenografted to subcutaneous beds of nude mice. After 4 or 8 weeks of growth, biopsies were taken from these xenografts and examined for the presence of Merkel cells, using immunocytochemistry with antibodies specific for simple epithelial-type cytokeratins and neuron-specific enolase (NSE) as well as using electron microscopy. Skin from the same fetuses at the time of transplantation was screened in the same way. In all fetuses, no (or very s…
Merkel cells in ontogenesis of human nails
1993
Digital skin of human fetuses is known to contain a particularly high concentration of Merkel cells. Using antibodies against the simple epithelial cytokeratins (CK) 18 and 20, which are sensitive and specific Merkel cell markers, we studied immunohistochemically the main adnexal structure of digital skin, the nail anlage, in human fetuses (9-22 weeks of gestation) for the presence of Merkel cells. As early as week 9 some clustered Merkel cells were detected in the early matrix primordium. In specimens of week 12-15, abundant Merkel cells were found in the nail anlagen, particularly in the epithelium of the proximal nail-fold and the dorsal and ventral side of the apex region. In contrast, …
A further analysis of secretory structures of some taxa belonging to the genus Hypericum (Clusiaceae) in relation to the leaf vascular pattern
2014
This work extends knowledge about the distribution of secretory structures (black nodules, translucent glands, and type A and B secretory canals) to other species of the genus Hypericum L., as only H. perforatum L. appears to have been widely investigated. Moreover, the current study was extended to include leaf vascular patterns. In the species studied, a possible correlation between the presence of black nodules and a particular biological form, that of hemicryptophytes scapose perennials such as H. perfoliatum L., H. perforatum L., H. pubescens Boiss., H. tetrapterum Fr., and H. triquetrifolium Turra, was noted. These black nodules are not present in H. androsaemum L. and H. hircinum L.,…
In vitro release of lectins by Phallusia mamillata hemocytes.
1991
Abstract α-Lactose specific lectins are released from Phallusia mamillata hemocytes during short-term cultures. The molecular weight of the subunits, the immunological cross-reaction and the sugar specificity suggest that the released lectins are similar to those isolated from the sonicated hemocytes. Because lectin release appears to take place independently of active protein synthesis, the possibility exists that lectins are pre-formed, stored in hemocytes and released when in vitro conditions stimulate the cells.
Putative p24 complexes in Arabidopsis contain members of the delta and beta subfamilies and cycle in the early secretory pathway
2013
p24 proteins are a family of type I membrane proteins localized to compartments of the early secretory pathway and to coat protein I (COPI)- and COPII-coated vesicles. They can be classified, by sequence homology, into four subfamilies, named p24α, p24β, p24γ, and p24δ. In contrast to animals and fungi, plants contain only members of the p24β and p24δ subfamilies, the latter probably including two different subclasses. It has previously been shown that transiently expressed red fluorescent protein (RFP)-p24δ5 (p24δ1 subclass) localizes to the endoplasmic reticulum (ER) at steady state as a consequence of highly efficient COPI-based recycling from the Golgi apparatus. It is now shown that tr…
Coupled transport of Arabidopsis p24 proteins at the ER–Golgi interface
2012
p24 proteins are a family of type I membrane proteins localized to compartments of the early secretory pathway and to coat protein I (COPI)- and COPII-coated vesicles. They can be classified, by sequence homology, into four subfamilies, named p24α, p24β, p24γ, and p24δ. In contrast to animals and fungi, plants contain only members of the p24β and p24δ subfamilies. It has previously been shown that transiently expressed red fluorescent protein (RFP)–p24δ5 localizes to the endoplasmic reticulum (ER) as a consequence of highly efficient COPI-based recycling from the Golgi apparatus. Using specific antibodies, endogenous p24δ5 has now been localized to the ER and p24β2 to the Golgi apparatus in…
Out for a Walk Along the Secretory Pathway During Programmed Cell Death
2015
This chapter provides a comprehensive updated analysis on the role of the secretory pathway in the orchestration of cell’s demise, an emerging and promising research topic in the field of plant programmed cell death (PCD). Since my first review on this topic, a plethora of data has been published supporting the concept that endomembrane system-forming subcellular compartments cooperate to coordinate cellular responses to developmental and environmental cues and thereby can dictate a cell’s ultimate fate. Thus, the early secretory pathway, encompassing the endoplasmic reticulum and Golgi apparatus, can be involved in the perception of extrinsic and intrinsic stimuli. It can also be an active…
A membrane associated metalloprotease cleaves Cry3Aa Bacillus thuringiensis toxin reducing pore formation in Colorado potato beetle brush border memb…
2007
AbstractInsect proteases are implicated in Bacillus thuringiensis insecticidal proteins mode of action determining toxin specificity and sensitivity. Few data are available on the involvement of proteases in the later steps of toxicity such as protease interaction with toxin–receptor complexes and the pore formation process. In this study, a Colorado potato beetle (CPB) midgut membrane metalloprotease was found to be involved in the proteolytic processing of Cry3Aa. Interaction of Cry3Aa with BBMV membrane proteases resulted in a distinct pattern of proteolysis. Cleavage was demonstrated to occur in protease accessible regions of domain III and was specifically inhibited by the metalloprote…