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., Fukuzawa, K. (1980) Thiobarbituric acid value of fresh homogenate of rat as parameter of lipid peroxidation in ageing, CCl 4 intoxication and vitamin E deficiency. Biochem. Med. 23 , 302–311. Fukuzawa K
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20 Werker, E., Lerner, H. R., Weimberg, R., Poljakoff-Mayber, A. (1983) Structural changes occurring in nuclei of barley root cells in response to a combined effect of salinity and ageing
The aim of the study was to investigate the relationships between the vascular plant species and the associated soil microbial properties at various stages of vegetation development on unclaimed hard coal mine spoil heaps in Upper Silesia (south Poland). The spontaneous vegetation, soil chemistry as well as the activity and structure of microbial communities were recorded on this specific habitat. The colliery heaps were divided into four age classes and the plant species composition and cover abundance were recorded on established plots (2 m × 2 m). The soil microbial activity under the vegetation patches was assessed using fluorescein diacetate hydrolytic activity (FDHA) and the soil microbial biomass and community composition were determined by phospholipid fatty acid (PLFA) biomarkers. Total microbial biomass in soils from the older vegetation plots was significantly higher than those in soils from the younger plots. In all studied samples, microbial communities consisted primarily of bacteria with the dominance of Gram negative bacteria over Gram positive and aerobic microorganisms were more dominant than anaerobic ones. Statistical analysis revealed a correlation between the type of vegetation and microbial community structure.
We assess if the structural and floristic diversity of Juniperus-Ilex forests from Pico Island (Azores) corresponds to a mosaic of different phases of a forest cycle, by identifying the phases of that cycle and the dynamic relations between them. Eight 100 m 2 plots were placed randomly in areas with structural and floristic differences but having in common the presence of live and/or dead individuals of the dominant tree species ( Juniperus brevifolia ). In each plot the number of seedlings, saplings, and adults as well as canopy height and width and maximum height of live Juniperus brevifolia and Ilex azorica adults were recorded. The floristic composition was determined in a 25 m 2 plot, placed inside each 100 m 2 plot. Juniperus-Ilex forests show a cyclic patch dynamic triggered by the senescence and death of even-aged individuals of J. brevifolia . In this forest cycle, five phases were identified, such as gap, building, mature, initial degenerative and final degenerative. The first two phases are dominated by J. brevifolia however in the degenerative phases I. azorica is the dominant tree species. The cycle may be divided into an upgrade series (comprising the first two phases) and a downgrade series (between the mature and final degenerative phases). In these forests there was no climax micro-succession detected since changes in the dominant tree species occur in the degenerative phases. This paper brings the first evidence for the existence of a forest cycle in Macaronesian forests.
The aim of this study was to investigate the effect of estradiol and progesterone and melatonin supplementation on TNF-a levels in ovariectomized and pinealectomized rats. The study was carried out on 42 adult, Spraque-Dawley strain female rats aged 6 months and weighing 200-250 grams. The rats were divided into 6 groups, each group contained 7 rats. Group 1: Sham-ovariectomized (Sham-Ovx), Group 2: Ovariectomized (Ovx), Group 3: Ovx and estradiol (E) and progesterone (P) supplemented (Ovx+E-P) group, Group 4: Ovx+E-P+Melatonin (M) supplemented group, Group 5: Ovx - Pinealectomized (Pnx) group, Group 6: Ovx - Pnx+E-P supplemented group. Serum TNF-a levels were determined after 4 weeks application period. Group 6 (Ovx-Pnx+E-P) has the highest serum TNF-a compared with other groups while group 2 (ovariectomized), has the lowest levels (P<0.001). Group 5 was higher than groups 1, 2, 3 and 4 (P<0.001). The results of the study show that ovariectomy reduces the serum level of TNF-a, but estradiol and progesterone application prevents this reduction in ovariectomized rats. However, pinealectomy intensifies the increases in TNF- a levels in ovariectomized and estradiol and progesterone supplemented rats, whereas melatonin reduces TNF- a levels in ovariectomized rats.
The lysosomal membrane-associated glycoproteins LAMP-1 and LAMP-2 are the major constituents of lysosomal membranes with still undefined biological functions. As autophagy is an alternative model of programmed cell death in which lysosomes play a crucial role, we hypothesize that LAMPs might participate in this phenomenon in the involuting thymus. Thymic glands from cases with acute (infection induced) and chronic (senile) involution were examined immunohistochemically for the expression of LAMPs. In acute involution LAMP-1 was localized mainly in medullary epithelial cells, in single macrophages and lymphocytes. Hassall's corpuscules were stained less intensely as compared to control specimens. The quantitative analysis showed a significantly elevated LAMP-2 expression compared to LAMP-1. LAMPs were detected with very slight reactivity in the senile thymus. The enhanced expression of LAMPs, and mainly of LAMP-2, in epithelial cells of incidentally involuted thymus might be an indicator of acute cell injury requiring autophagic degradation of damaged structures. The diminished expression of LAMPs in age-involuted thymus could be a sign of the morphological reorganization and the functional disregulation of the gland. In conclusion, we present novel evidence for differential expression of LAMP-1 and LAMP-2 in thymic involution suggesting their possible involvement in the process of accidental involution of the thymic gland.
The objective of the work was to characterize the presence of spontaneous micronucleated erythrocytes (MNES) from peripheral blood of bottlenose dolphins (Tursiops truncatus) to evaluate the possibility to use this species as potential bioindicator of genotoxic compounds. Forty-eight blood samples from 12 bottlenose dolphins were obtain from three Mexican dolphinariums, and from 10 dolphins was possible to obtain more than one sample at different sampling times. Smears were processed and observed with an epifluorescence microscope. The average of MNES and polychromatic erythrocytes (PCE) from the 48 samples was 24.3±6.1 MNES/10,000 total erythrocytes (TE), and 9.1±5.5 PCE/1,000 TE. MNES and PCE number did not show differences between gender and age. No variations in the MNES values of the bottlenose dolphins that were sampled more than one occasion were found. Comparisons among dolphinariums revealed differences in MNES frequency, with the highest significant frequency observed in dolphins from dolphinarium “A” (26.0±5.9 MNES/10,000 TE) than dolphinarium “B” (19.5±3.1 MNES/10,000 TE) (p<0.05) and dolphinarium “C” (18.6±3.5 MNES/10,000 TE) (p<0.007). The presence of MNES and PCE in the bottlenose dolphin may provide a useful marine mammal model to detect DNA damage by means of micronuclei test in peripheral blood erythrocytes to evaluate genotoxicity and cytotoxicity expositions.
Cardiac failure secondary to myocardial fibrosis (MF) significantly contributes to death in Duchenne muscular dystrophy (DMD), a fatal form of muscle disease. In aging, the mdx mice, an animal model of DMD, MF is similar to that observed in humans. Nitric oxide-based therapy has been proposed to retard MF in DMD and a candidate is L-arginine (L-arg). In this study we evaluated the effects of long-term therapy with L-arg in the MF of mdx mice. mdx mice (6 months old) were treated with L-arg in drinking water. Control mdx mice received water only. After 15 months of treatment, hearts were stained with Masson’s trichrome for analysis of MF and with hematoxilyn and eosin for analysis of inflammation and cardiomyocyte damage. We observed that MF was not affected (29.5 ± 2.5% of MF area for control vs 31.4 ± 2% for L-arginine-treated animals; P > 0.05). The density of inflammatory cells was reduced (169 ± 12 cells/mm 2 in control vs 102 ± 9 cells/mm 2 in L-arg-treated; P < 0.05). The present study shows that long-term administration of L-arg is not effective in retarding MF in mdx dystrophinopathy.
Modification in the metabolism of phenolic compounds under boron (B) deficiency conditions was studied in tea plants. Plants were grown from seed, treated with low B in hydroponic medium under environmentally controlled conditions for six weeks. Dry matter production and B content of plants were significantly declined under B deficiency conditions. Boron starvation resulted in rising phenylalanine ammonia lyase activity in the young leaves and declining polyphenol oxidase activity in the roots. Soluble phenolics fraction was increased up to 3.4-fold in the young leaves while did not influence by B nutrition in the old leaves and roots. Cell wall (CW) bound phenolics and lignin content was lower in B-deficient plants compared with B-sufficient ones. Boron deficiency increased significantly activity of soluble peroxidase (POD) only in the leaves. Activity of ionically bound POD was decreased in the old leaf and roots while it increased in the young leaves upon B deprivation. Activity of covalently bound POD decreased in the roots and leaves of different age in low B plants. Our results suggested that tea plant is highly tolerant species to B deficiency and CW tightening and accumulation of oxidized phenolics are not mechanisms for growth inhibition under B deficiency conditions.
