220 research outputs found
Impact of Age and Body Site on Adult Female Skin Surface pH
Background: pH is known as an important parameter in epidermal barrier function and homeostasis. Aim: The impact of age and body site on skin surface pH (pH(SS)) of women was evaluated in vivo. Methods: Time domain dual lifetime referencing with luminescent sensor foils was used for pH(SS) measurements. pH(SS) was measured on the forehead, the temple, and the volar forearm of adult females (n = 97, 52.87 +/- 18.58 years, 20-97 years). Every single measurement contained 2,500 pH values due to the luminescence imaging technique used. Results: pH(SS) slightly increases with age on all three investigated body sites. There are no significant differences in pH(SS) between the three investigated body sites. Conclusion: Adult pH(SS) on the forehead, the temple and the volar forearm increases slightly with age. This knowledge is crucial for adapting medical skin care products. Copyright (C) 2012 S. Karger AG, Base
Gene expression profile of AIDS-related Kaposi's sarcoma
BACKGROUND: Kaposi's Sarcoma (KS) is a proliferation of aberrant vascular structures lined by spindle cells, and is caused by a gammaherpes virus (HHV8/KSHV). Its course is aggravated by co-infection with HIV-1, where the timing of infection with HIV-1 and HHV8 is important for the clinical outcome. METHODS: In order to better understand the pathogenesis of KS, we have analysed tissue from two AIDS-KS lesions, and from normal skin by serial analysis of gene expression (SAGE). Semi-quantitative RT-PCR was then used to validate the results. RESULTS: The expression profile of AIDS-related KS (AIDS-KS) reflects an active process in the skin. Transcripts of HHV8 were found to be very low, and HIV-1 mRNA was not detected by SAGE, although it could be found using RT-PCR. Comparing the expression profile of AIDS-KS tissue with publicly available SAGE libraries suggested that AIDS-KS mRNA levels are most similar to those in an artificially mixed library of endothelial cells and leukocytes, in line with the description of KS lesions as containing spindle cells with endothelial characteristics, and an inflammatory infiltrate. At least 64 transcripts were found to be significantly elevated, and 28 were statistically downregulated in AIDS-KS compared to normal skin. Five of the upregulated mRNAs, including Tie 1 and sialoadhesin/CD169, were confirmed by semi-quantitative PCR to be elevated in additional AIDS-KS biopsies. Antibodies to sialoadhesin/CD169, a known marker of activated macrophages, were shown to specifically label tumour macrophages. CONCLUSION: The expression profile of AIDS-KS showed 64 genes to be significantly upregulated, and 28 genes downregulated, compared with normal skin. One of the genes with increased expression was sialoadhesin (CD169). Antibodies to sialoadhesin/CD169 specifically labelled tumour-associated macrophages, suggesting that macrophages present in AIDS-KS lesions belong to a subset of human CD169+ macrophages
Intestinal fibrovascular nodules caused by Schistosoma mansoni infection in Calomys callosus Rengger, 1830 (Rodentia: Cricetidae): a model of concomitant fibrosis and angiogenesis
Lysosomes in iron metabolism, ageing and apoptosis
The lysosomal compartment is essential for a variety of cellular functions, including the normal turnover of most long-lived proteins and all organelles. The compartment consists of numerous acidic vesicles (pH ∼4 to 5) that constantly fuse and divide. It receives a large number of hydrolases (∼50) from the trans-Golgi network, and substrates from both the cells’ outside (heterophagy) and inside (autophagy). Many macromolecules contain iron that gives rise to an iron-rich environment in lysosomes that recently have degraded such macromolecules. Iron-rich lysosomes are sensitive to oxidative stress, while ‘resting’ lysosomes, which have not recently participated in autophagic events, are not. The magnitude of oxidative stress determines the degree of lysosomal destabilization and, consequently, whether arrested growth, reparative autophagy, apoptosis, or necrosis will follow. Heterophagy is the first step in the process by which immunocompetent cells modify antigens and produce antibodies, while exocytosis of lysosomal enzymes may promote tumor invasion, angiogenesis, and metastasis. Apart from being an essential turnover process, autophagy is also a mechanism by which cells will be able to sustain temporary starvation and rid themselves of intracellular organisms that have invaded, although some pathogens have evolved mechanisms to prevent their destruction. Mutated lysosomal enzymes are the underlying cause of a number of lysosomal storage diseases involving the accumulation of materials that would be the substrate for the corresponding hydrolases, were they not defective. The normal, low-level diffusion of hydrogen peroxide into iron-rich lysosomes causes the slow formation of lipofuscin in long-lived postmitotic cells, where it occupies a substantial part of the lysosomal compartment at the end of the life span. This seems to result in the diversion of newly produced lysosomal enzymes away from autophagosomes, leading to the accumulation of malfunctioning mitochondria and proteins with consequent cellular dysfunction. If autophagy were a perfect turnover process, postmitotic ageing and several age-related neurodegenerative diseases would, perhaps, not take place
Characterization of Granulations of Calcium and Apatite in Serum as Pleomorphic Mineralo-Protein Complexes and as Precursors of Putative Nanobacteria
Calcium and apatite granulations are demonstrated here to form in both human and
fetal bovine serum in response to the simple addition of either calcium or
phosphate, or a combination of both. These granulations are shown to represent
precipitating complexes of protein and hydroxyapatite (HAP) that display marked
pleomorphism, appearing as round, laminated particles, spindles, and films.
These same complexes can be found in normal untreated serum, albeit at much
lower amounts, and appear to result from the progressive binding of serum
proteins with apatite until reaching saturation, upon which the mineralo-protein
complexes precipitate. Chemically and morphologically, these complexes are
virtually identical to the so-called nanobacteria (NB) implicated in numerous
diseases and considered unusual for their small size, pleomorphism, and the
presence of HAP. Like NB, serum granulations can seed particles upon transfer to
serum-free medium, and their main protein constituents include albumin,
complement components 3 and 4A, fetuin-A, and apolipoproteins A1 and B100, as
well as other calcium and apatite binding proteins found in the serum. However,
these serum mineralo-protein complexes are formed from the direct chemical
binding of inorganic and organic phases, bypassing the need for any biological
processes, including the long cultivation in cell culture conditions deemed
necessary for the demonstration of NB. Thus, these serum granulations may result
from physiologically inherent processes that become amplified with calcium
phosphate loading or when subjected to culturing in medium. They may be viewed
as simple mineralo-protein complexes formed from the deployment of
calcification-inhibitory pathways used by the body to cope with excess calcium
phosphate so as to prevent unwarranted calcification. Rather than representing
novel pathophysiological mechanisms or exotic lifeforms, these results indicate
that the entities described earlier as NB most likely originate from calcium and
apatite binding factors in the serum, presumably calcification inhibitors, that
upon saturation, form seeds for HAP deposition and growth. These calcium
granulations are similar to those found in organisms throughout nature and may
represent the products of more general calcium regulation pathways involved in
the control of calcium storage, retrieval, tissue deposition, and disposal
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