International journal of tissue reactions最新文献

Radiation damage results in blood-brain barrier damage followed by blood plasma transfer into the neuropil. The transferred liquid contains high amounts of biologically active substances/proteinases including factor Xa and a free pool of serum trypsin, which is not bound to antiproteases (alpha1 AT, alpha2-macroglobulin). The aim of this study was to follow up expression of proteinase-activated receptor-2 (PAR-2) in the brains of Wistar rats after single exposure to radiation at 26 Gy (60Co, 23 min, 15 sec). After irradiation, the animals were sacrificed on days 10, 20, 30 and 40. Control rat brains served as negative control. Coronal sections of caudal diencephalons were investigated using histology and immunohistochemistry. Polyclonal goat specified antibody against the NH-end of murine and rat PAR-2. Significant PAR-2 membrane positivity of scattered swollen neurons in deeper cortical layers was found in irradiated animals compared with controls. Although this membrane positivity was noticed in all irradiated animals, the most prominent occurred on day 30. Diffuse cytoplasmic positivity was also demonstrated on shrunken neurons in the cortex and hippocampus. Increased cytoplasmic and polarized membrane positivity was also noticed on the neurons of hypothalamic nuclei The causal relationship between blood-brain barrier damage, PAR-2 activation and neurodegeneration has not yet been verified. However, the present findings indicate that PAR-2 mediates a certain cellular response. It remains to be demonstrated whether this is a response to higher concentrations of factor Xa, a free pool of trypsin or other unknown possible proteinases in brain tissue; whether changes in PAR-2 expression are consequences of direct radiation damage to neuronal cells; whether this reaction is protective; and whether primary PAR-2 activation results in neuronal damage.

In the search for alternative methods to animal testing, the Hen's egg test on chorioallantoic membrane (HET-CAM) plays a central role in evaluating the innocuity of active ingredients. Therefore, in the following studies we combined the HET-CAM test with histological evaluation in order to increase the sensitivity of evaluation. Twenty active ingredients from four different categories of origin (vegetal, marine, biotechnological and chemical synthetic) were subjected to innocuity evaluation at two different concentrations (pure and 10%). We performed the HET-CAM test and histological evaluation after trypan blue and hematoxylin-eosin staining of the chorioallantoic membrane to microscopically evaluate its state of damage after application of each active ingredient. These studies showed that when the active ingredient was diluted (10%), no discrepancy was seen between the classical HET-CAM evaluation and the histological reading of the chorioallantoic membrane. The histological findings corresponded with the visual observation of the CAM. When the active ingredients were tested at pure concentration, 7 out of 20 tested products demonstrated discrepancy between the two tests. In six cases, the histological examination revealed signs of irritation, such as hyperemia, while visual HET-CAM evaluation was negative. In another case, the histological examination revealed a slight hemorrhage whereas the HET-CAM reading showed only hyperemia. Moreover, the results of trypan blue staining corroborated the histological evaluation of the CAM. These results strongly suggest that the combination of histological and visual HET-CAM tests is of interest for a more sensitive evaluation of the innocuity of cosmetic active ingredients. This additional sensitivity may help to prevent some cases of in vivo intolerance reactions.

Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) are prone to dyslipidemia and have a high risk of cardiovascular death. The aim of this study was to assess the effects of a 6-month treatment with simvastatin (10 mg at bedtime) on markers of endothelial cell injury in 12 hypercholesterolemic CAPD patients. Cholesterol and low-density lipoprotein cholesterol fell significantly after 1 month of therapy. Simvastatin treatment significantly decreased concentrations of vascular cell adhesion molecule and intracellular adhesion molecule after 3 and 6 months of the therapy, respectively. Thrombomodulin decreased significantly after 6 months of the treatment, whereas von Willebrand's factor, P-selectin and E-selectin remained unaltered during simvastatin therapy. Simvastatin, an effective hypolipemic agent, favorably affects endothelial function and may potentially slow the progression of atherosclerosis and confer protection from thrombotic complications in patients with hypercholesterolemia undergoing CAPD.

Rheumatoid arthritis is an inflammatory joint and systemic disease believed to be of autoimmune origin. Predisposing factors also include genetic factors, such as the presence of alleles HLA-DRB1 *04, (HLA-DRB1 *0401, *0404, *0405 and *0408) and, in other ethnic groups, of subtypes DRB1 *0101, *0102 and DRB1 *1001. These genetic factors are believed to raise the risk of developing the disease. In rheumatoid arthritis, as in other chronic inflammatory diseases, iron metabolism dysfunction has been observed and attributed to inflammation. In hereditary hemochromatosis, tissue sideropexia is associated with a peculiar form of arthropathy. C282Y is a point mutation involving the replacement of a cysteine with a tyrosine at position 282 of the HFE protein. When found in homozygosis, there is a close association with hereditary hemochromatosis, accounting for one of the causes of iron metabolism dysfunction observed in this disease. The aim of this study was to compare the frequency of C282Y in patients with rheumatoid arthritis with that in patients with different forms of spondylarthritis and to correlate these findings with iron metabolism parameters. In the group of patients with rheumatoid arthritis, 2/24 (8.34%) were found to be positive for the C282Y mutation in the case of heterozygosis compared with 3/24 (12.5%) of patients with spondylarthritis. In patients with the C282Y mutation, ferritin levels were significantly higher than those in controls; conversely, serum iron levels were higher in patients with spondylarthritis. Serum transferrin levels, although slightly higher in rheumatoid arthritis patients, showed no statistically significant differences.

Evidence is accumulating that intermediates of oxygen reduction may be associated with the development of alcoholic disease. Free radical-induced perturbation of the oxidant/antioxidant balance in the cell is widely recognized as the main causative factor of age-related disorders. In the present study we investigated the effects of 20 months of ethanol consumption on the antioxidant defense system in different rat organs compared with normal aging in the absence and presence of treatment with L-acetyl carnitine. We demonstrate that aged rats underwent significant perturbation of the antioxidant defense system, as indicated by depletion of reduced glutathione (GSH) content, increased oxidized GSH, free radical-induced luminescence associated with increased hydroxynonenal content and decreased GSH reductase activity. These modifications, observed particularly in brain and liver compared with other organs, were enhanced by long-term alcohol exposure and, interestingly, were significantly reduced with acetyl carnitine supplements. Our results indicate that decreased GSH reductase activity and thiol depletion are important factors in effecting a pathogenic role for oxidative stress in aging and in all situations in which age-correlated and oxidant-induced changes occur, such as in alcoholism. Administration of acetyl carnitine greatly reduces these metabolic abnormalities. Our findings support its pharmacological potential in the management of alcoholic disturbances.

We examined the effect of local ischemic preconditioning on postradiation lipid peroxidation in the serum of total body irradiated rats. Markers of peroxidative damage provoked by radiation alone or radiation preceeded by ischemic preconditioning were thiobarbituric acid reactive substances, triglycerides and uric acid concentrations in serum. These data indicated that local ischemic preconditioning modifies the peroxidizing effects of radiation through inhibition of free radical-dependent lipid peroxidation. Other unrecognized mechanisms are probably also involved. Uric acid could act as an antioxidant against radiation alone and local preconditioned ischemia together with radiation.

Chronic alcoholism is a major public health problem and causes multiorgan diseases and toxicity. Although the majority of ethanol ingested is metabolized by the liver, it has intoxicating effects in the brain. Evidence is accumulating that intermediates of oxygen reduction may be associated with the development of alcoholic disease. Several studies have shown the capacity of carnitine and its derivatives to influence ethanol metabolism. We have previously demonstrated that preadministration of L-carnitine to rats receiving ethanol significantly reduced fatty acid ethyl esters in different organs and that the carnitine/acylcarnitine system is crucial for maintaining a functional acetyl-CoA/CoA ratio under conditions in which cellular homeostasis is exposed to the deleterious effects of accumulating organic acids. Ethanol, administered to rats for 20 months, induced significant changes in the status of glutathione, primarily in the brain regions of hippocampus and cerebellum, followed by cortex and striatum, where a decrease in reduced glutathione (GSH) and the GSH/oxidized glutathione ratio was found. The same brain regions showed a significant increase in free radical-induced luminescence and hydroxynonenal (HNE), which were associated with decreased GSH reductase activity. Long-term supplementation with acetyl carnitine significantly reduced GSH depletion, particularly in the brain regions of hippocampus, an effect associated with decreased luminescence and HNE formation. In addition, acetyl carnitine treatment increased GSH reductase and arginase activities. Our results indicate that decreased GSH reductase activities associated with thiol depletion are important factors sustaining a pathogenic role in alcohol-related pathologies. Administration of acetyl carnitine greatly reduces these metabolic abnormalities. This evidence supports the pharmacological potential of acetyl carnitine in the management of alcoholic disturbances.

Leptin, a circulating hormone secreted mainly from adipose tissues, is involved in the control of body weight. Recently, leptin was found to be an angiogenic factor and its vitreous levels were shown to be elevated in patients with angiogenic eye diseases such as proliferative diabetic retinopathy. However, the role of leptin in diabetic retinopathy is not fully understood. Since pericyte loss and dysfunction have been considered to be one of the characteristic changes of the early phases of diabetic retinopathy, we investigated the effects of leptin on the growth and function of bovine cultured retinal pericytes. Although it did not affect cell growth, leptin significantly up-regulated pericyte messenger ribonucleic acid levels of an endogenous angiogenic stimulator, vascular endothelial growth factor (VEGF). Leptin was also found to significantly inhibit gene expression of pigment epithelium-derived factor (PEDF), the most potent angiogenesis inhibitor in the mammalian eye, in pericytes. The present study suggests that leptin might elicit angiogenesis through VEGF induction as well as PEDF suppression in pericytes and could thus be involved in the development and progression of diabetic retinopathy, especially in obese insulin-resistant patients.

Hormones play a central role in skin appearance and are implicated in skin aging. Recently, along with the remarkable increase in interest in natural products, the application of phytohormones in antiaging products has become very important. In this context, we developed date palm kernel extract. Date palm kernel is rich in phytohormones and we investigated the antiaging properties of date palm kernel in this in vivo study on wrinkles. Ten healthy women volunteers, between the ages of 46 and 58 years, applied the cream formula with 5% date palm kernel or placebo on the eye area twice a day for 5 weeks. The evaluation was made both clinically and by silicon replica analysis followed by statistical analysis using the Wilcoxon test. Silicon replica results showed that topical application of date palm kernel reduced the total surface of wrinkles by 27.6% (p = 0.038). Moreover, date palm kernel reduced the depth of wrinkles by 3.52% (p = 0.0231). These results are statistically significant and were clinically confirmed where visual improvement was seen in 60% of the volunteers treated. This in vivo study demonstrates that date palm kernel exhibits a significant antiwrinkle effect and is therefore of interest in antiaging skin care products.