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1.
A link between biological and human sciences may be established, under the condition that we should admit the existence of reciprocal influences between them. The model for the regulation of agonistic antagonistic couples (MRAAC) is built from the study of biological systems and gives rise to specific types of control. This model can be helpful in decision processes in some human sciences such as management, economical and political strategies. The reason for such an opportunity lies in the fact that MRAAC is a general and phenomenological model able to incorporate the whole of the agonistic antagonistic systems. This type of regulation might be related to the concept of the viability of a system (yet also valid for human science systems) and to a functional and structural pattern which is the basis for agonistic antagonistic networks.  相似文献   

2.
Changes in cytosolic free Ca2+ concentration ([Ca2+]c) play a crucial role in the control of insulin secretion from the electrically excitable pancreatic β-cell. Secretion is controlled by the finely tuned balance between Ca2+ influx (mainly through voltage-dependent Ca2+ channels, but also through voltage-independent Ca2+ channels like store-operated channels) and efflux pathways. Changes in [Ca2+]c directly affect [Ca2+] in various organelles including the endoplasmic reticulum (ER), mitochondria, the Golgi apparatus, secretory granules and lysosomes, as imaged using recombinant targeted probes. Because most of these organelles have specific Ca2+ influx and efflux pathways, they mutually influence free [Ca2+] in the others. In this article, we review the mechanisms of control of [Ca2+] in various compartments and particularly the cytosol, the endoplasmic reticulum ([Ca2+]ER), acidic stores and mitochondrial matrix ([Ca2+]mito), focusing chiefly on the most important physiological stimulus of β-cells, glucose. We also briefly review some alterations of β-cell Ca2+ homeostasis in Type 2 diabetes.  相似文献   

3.
Epidemiologic studies indicate that the incidence of gastric cancer is higher in males than in females. Although the mechanisms mediating this difference are unclear, a role for estrogens has been proposed. We used Western blotting to evaluate the role of estrogen receptor (ER) subtypes ERα and ERβ and proliferating cell nuclear antigen (PCNA) in N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis in Wistar rats; ERα and ERβ mRNA levels also were analyzed by quantitative real-time RT-PCR analysis. The incidence of gastric cancer was significantly higher in male than female rats. In both sexes, ERα expression was similar in MNNG-treated cancerous and noncancerous tissues and normal gastric tissue. However, ERβ expression in MNNG-treated cancerous and noncancerous tissues was significantly lower in male rats and higher in female rats than that in normal gastric tissue; MNNG-induced cancerous tissue showed the highest ERβ expression. PCNA expression in MNNG-treated cancerous tissues was higher than that in noncancerous tissues, and was higher in male rats than female rats. Western blotting results were consistent with the mRNA changes determined by quantitative real-time RT-PCR. The present study provides evidence of a sex-associated difference in ERβ and PCNA expression in MNNG-induced gastric cancers in Wistar rats.  相似文献   

4.
Human leukocyte antigen (HLA) class Ⅱ alleles are involved in antigen processing and presentation to T lymphocytes during fungal infections. However, few studies have investigated HLA genes in fungal diseases, or in sporotrichosis infections. Here, the frequencies of HLA-DRβ1 in 50 healthy volunteers and 9 patients with sporotrichosis from an endemic area in Mexico were determined to define their role in genetic susceptibility to this infection. Also, the frequencies of HLA-DRβ1 haplotypes were compared with a historic control group of healthy Mexican individuals. The patients presented that DR4 and DR8 increased, which were more than twice the control''s values, whereas local controls (endemic area) presented DR*04:01 increased, compared with the control group from Mexico City. The data suggest that involvement of HLA antigens could affect the outcomes of the host-fungi interaction in sporotrichosis by regulating the immune response to Sporothrix schenckii complex.  相似文献   

5.
6.
poor OS. HMP19 plays a role in metastasis/tumor suppression and offers a prognostic value for EOC. HMP19, as a new inhibitor, strongly inhibits metastasis and partially attenuates tumor growth in EOC.  相似文献   

7.
Cisplatinum [cis-diamminedichloroplatinum(II)] is one of the most active antitumour agents and its effect is mainly due to the formation of cisplatinum-DNA crosslinks. Formation of cisplatinum-DNA intrastrand crosslinks in nucleated white blood cells of patients was measured, both in (pretreatment) samples exposed in vitro and in cells collected immediately after in vivo exposure to cisplatinum. Large interpatient variations were found. The in vitro results showed a linear correlation with the in vivo data (cc = 0.91). The in vitro measurements of crosslinks may allow prediction of response and avoidance of toxicity in individual patients.  相似文献   

8.
9.
The aim of the study was to investigate theAmbrosia pollen concentrations inselected Polish cities and for Kraków torelate it to some meteorological factors.Sampling was carried out in Kraków in1982–1997 and in Rabka in 1992–1996 with theuse of the gravimetric method. In Zakopane,Kraków, Ostrowiec witokrzyski,Warszawa and Pozna in 1995–1996 both thegravimetric and volumetric methods (Burkardtrap) were employed. In Kraków themonitoring has been performed since 1994 usingthe volumetric method. The results show theragweed pollen presence in August and Septemberwith the tendency to appear more frequently inAugust in some years. In Kraków (1994–1999)Ambrosia pollen was found either in thelast two weeks of August or in the first twoweeks of September which seems to be a regularand repeatable pattern every two years.Seasonal fluctuations of Ambrosia pollenconcentration do not show a clear increasingtendency except at Warszawa and Ostrowiecwitokrzyski in 1996 and at Krakówin 1999. Percentage of Ambrosia pollen inannual sums of total pollen is very low anddoes not exceed 1% except at Ostrowiecwitokrzyski in 1996 (1.2%) and atKraków in 1999 (2%). For Kraków theanalysis of some meteorological factors (Tmax,Tmin, precipitation, wind direction) wasperformed. High temperature and lack of rain orlow precipitation correlate well with ragweedpollen concentrations. During the Ambrosia pollen seasons ESE, E, S, SE, WSW, SWwind directions prevailed which could suggest along-distance transport from Ukraine, the CzechRepublic, Slovakia and also from Hungary, one ofthe most ragweed-polluted countries.  相似文献   

10.
Cisplatinum [cis-diamminedichloroplatinum(II)] is one of the most active antitumour agents and its effect is mainly due to the formation of cisplatinum-DNA crosslinks. Formation of cisplatinum-DNA intrastrand crosslinks in nucleated white blood cells of patients was measured, both in (pretreatment) samples exposed in vitro and in cells collected immediately after in vivo exposure to cisplatinum. Large interpatient variations were found. The in vitro results showed a linear correlation with the in vivo data (cc=0.91). The in vitro measurements of crosslinks may allow prediction of response and avoidance of toxicity in individual patients.  相似文献   

11.
We tested if variations (i.e., breadth) in morphology and habitat use vary predictably among six aquatic gastropod species that were collected across Indiana and Illinois, USA. We predicted that interspecific morphological variation would positively covary with variation in habitat use among species. We used geometric morphometrics (Procrustes technique and relative warp analysis) to quantify morphology and multivariate analyses (PCA) to quantify habitat. Increased morphological breadth did not vary predictably with increased habitat breadth. However, we found that life history traits correspond with patterns in morphological and habitat breadth for these six aquatic gastropods. Pulmonate gastropods (use lungs for respiration) that lack an operculum cover exhibited decreased morphological breadth compared to coenogastropods (use gills for respiration). This pattern may ultimately be a function of behavioral adaptations in freshwater gastropods. Gastropods that are capable of breathing air or using other behavioral modifications such as burrowing to escape predators may not require high morphological breadth. Conversely, selection may favor higher morphological breadth in gastropods with gills that also do not move out of the water column to escape predators.  相似文献   

12.
Because previous research has shown a relationship between maximal squat strength and sprint performance, this study aimed to determine if changes in maximal squat strength were reflected in sprint performance. Nineteen professional rugby league players (height = 1.84 ± 0.06 m, body mass [BM] = 96.2 ± 11.11 kg, 1 repetition maximum [1RM] = 170.6 ± 21.4 kg, 1RM/BM = 1.78 ± 0.27) conducted 1RM squat and sprint tests (5, 10, and 20 m) before and immediately after 8 weeks of preseason strength (4-week Mesocycle) and power (4-week Mesocycle) training. Both absolute and relative squat strength values showed significant increases after the training period (pre: 170.6 ± 21.4 kg, post: 200.8 ± 19.0 kg, p < 0.001; 1RM/BM pre: 1.78 ± 0.27 kg·kg(-1), post: 2.05 ± 0.21 kg·kg(-1), p < 0.001; respectively), which was reflected in the significantly faster sprint performances over 5 m (pre: 1.05 ± 0.06 seconds, post: 0.97 ± 0.05 seconds, p < 0.001), 10 m (pre: 1.78 ± 0.07 seconds, post: 1.65 ± 0.08 seconds, p < 0.001), and 20 m (pre: 3.03 ± 0.09 seconds, post: 2.85 ± 0.11 seconds, p < 0.001) posttraining. Whether the improvements in sprint performance came as a direct consequence of increased strength or whether both are a function of the strength and power mesocycles incorporated into the players' preseason training is unclear. It is likely that the increased force production, noted via the increased squat performance, contributed to the improved sprint performances. To increase short sprint performance, athletes should, therefore, consider increasing maximal strength via the back squat.  相似文献   

13.
We have previously shown that 4 wk of exercise training early in life normalizes the otherwise greatly reduced pancreatic β-cell mass in adult male rats born small. The aim of the current study was to determine whether a similar normalization in adulthood of reduced skeletal muscle mitochondrial biogenesis markers and alterations in skeletal muscle lipids of growth-restricted male rats occurs following early exercise training. Bilateral uterine vessel ligation performed on day 18 of gestation resulted in Restricted offspring born small (P < 0.05) compared with both sham-operated Controls and a sham-operated Reduced litter group. Offspring remained sedentary or underwent treadmill running from 5-9 (early exercise) or 20-24 (later exercise) wk of age. At 24 wk of age, Restricted and Reduced litter offspring had lower (P < 0.05) skeletal muscle peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) protein expression compared with Control offspring. Early exercise training had the expected effect of increasing skeletal muscle markers of mitochondrial biogenesis, but, at this early age (9 wk), there was no deficit in Restricted and Reduced litter skeletal muscle mitochondrial biogenesis. Unlike our previous observations in pancreatic β-cell mass, there was no "reprogramming" effect of early exercise on adult skeletal muscle such that PGC-1α was lower in adult Restricted and Reduced litter offspring irrespective of exercise training. Later exercise training increased mitochondrial biogenesis in all groups. In conclusion, although the response to exercise training remains intact, early exercise training in rats born small does not have a reprogramming effect to prevent deficits in skeletal muscle markers of mitochondrial biogenesis in adulthood.  相似文献   

14.

Background

The value of genotyping to predict variant phenotypes in patients with phenylalanine hydroxylase (Pah) deficiency is a matter of debate. However, there exists no comprehensive population relationship study focused on the Han Chinese.

Methods

We analyzed genotype–phenotype correlation for 186 different genotypes in 338 unrelated Chinese patients harboring 109 different Pah mutations. Two systems were used in this process. The first was a phenotype prediction system based on arbitrary values (AV) attributed to each mutation. The second was a pair-wise correlation analysis. The observed phenotype for AV analysis was the corresponding metabolic phenotype stratified according to the pretreatment phenylalanine (Phe) value.

Results

We found that the observed phenotype matched the predicted phenotype in 54.41% of 272 patients for whom AV information was available; the highest degree of concordance (61.83%) was found in patients with null/null genotypes, whereas the lowest “concordance rate” (32.69%) was observed for patients with expected mild-PKU phenotype. There are repeated inconsistencies for such mutations as R241C, R243Q, R261Q, V388M, V399V, R408Q, A434D and EX6-96A>G which are associated with variable phenotypes in patients with identical genotype. Significant correlations were disclosed between pretreatment Phe values and predicted residual activity (r = − 0.45643, P < 0.0001) or AV sum (r = − 0.59523, P < 0.0001).

Conclusion

Our study supports the notion that the Pah mutation genotype is the main determinant of metabolic phenotype in most patients in a particular population, and provided novel insights into the values that underpin the subsequent treatment and the prognosis of PKU in Chinese.  相似文献   

15.
Four hectares were inventoried for all trees with diameter at breast height (DBH) of 10cm or greater in a terra firme forest 200km Northeast of Manaus, Central Amazonia. The number of species varied from 137 to 168, the number of individuals from 639 to 713, total basal area from 32.8 to 40.2 and total biomass from 405 to 560 tons per hectare. The majority of trees, 90%, had a DBH between 10 and 30 cm. Leguminosae, Lauraceae, Sapotaceae, Chrysobalanaceae and Moraceae were the most rich families (number of species) in all sampled hectares. The most abundant families in all sampled hectares (number of trees) were Leguminosae, Burseraceae, Myristicaceae, Moraceae and Chrysobalanaceae. The most dominant families in all sampled hectares (basal area and biomass) were Leguminosae, Lecythidaceae, Chrysobalanaceae, Bombacaceae and Moraceae. Similarity indexes at family level varied from 67 to 86% between the four hectares sampled. Alexa grandiflora (Leguminosae) was the most abundant species in the hectares one and three, while Scleronema micranthum (Bombacaceae), and Oenocarpus bacaba (Palmae) were the most abundant species in hectares two and four. S. micranthum was the most dominant species (basal area) in hectares one and two, while Bertholletia excelsa (Lecythidaceae) and Goupia glabra (Celastraceae) were the most dominant species in hectares three and four. S. micranthum (Bombacaceae), Buchenavia sp. 2 (Combretaceae), B. excelsa (Lecythidaceae) Couepia obovata (Chrysobalanaceae) were the most dominant species (biomass) in hectares one to four, respectively. Similarity indexes at species level varied from 26 to 44% between the four sampled hectares. This inventory is compared with previous studies and it was found that, in our study area, there was a greater proportion of trees of 60cm diameter or more and consequently a considerably higher total basal area. It is concluded that there are still an inadequate number of inventories of Amazonian terra firme forests to elucidate the major floristic pattern a both regional and local levels. Since the area is a mosaic of distinct floristic communities it is essential to obtain further standardized inventory data in order to set adequate conservation policies for the region.  相似文献   

16.
The hippocampus plays a key role in declarative learning and memory [1]. Hippocampal long-term potentiation (LTP) is a type of synaptic plasticity that has been widely studied as a syn-aptic mechanism underlying learning and memory[27]. It has been reported that in vitro LTP in area CA1 is subjected to b-adrenergic modulation. For example, the theta-pulse stimulation (510 Hz), a neutral frequency not modifying synaptic strength, can elicit a robust LTP in area CA1 in slice when the b-adr…  相似文献   

17.
Detection of chemical compounds in food sources is based on the activation of 7 transmembrane gustatory receptors (GRs) in mammals and in insects such as Drosophila, although the receptors are not conserved between the classes. Different combinations of Drosophila GRs are involved in the detection of sugars, but the activated signaling cascades are largely unknown. Because 7 transmembrane receptors usually couple to G-proteins, we tried to unravel the intracellular signaling cascade in taste neurons by screening heterotrimeric G-protein mutant flies for gustatory deficits. We found the subunit Goα to be involved in feeding behavior and cell excitability by different transgenic and pharmacological approaches. Goα is involved in the detection of sucrose, glucose, and fructose, but not with trehalose and maltose. Our studies reveal that Goα plays an important role in the perception of some sweet tastants. Because the perception of other sweet stimuli was not affected by mutations in Goα, we also found strong indication for the existence of multiple signaling pathways in the insect gustatory system.  相似文献   

18.
Clean safe water is increasingly valuable everywhere. Everyone lives in a watershed and desires high quality water. However, many activities lower water quality by way of increased productivity and pollution. Traditional limnological knowledge has been successfully applied to improve temperate zone lakes and streams.  相似文献   

19.
Sumoylation is an essential posttranslational modification that participates in many biological processes including stress responses. However, little is known about the mechanisms that control Small Ubiquitin-like MOdifier (SUMO) conjugation in vivo. We have evaluated the regulatory role of the heterodimeric E1 activating enzyme, which catalyzes the first step in SUMO conjugation. We have established that the E1 large SAE2 and small SAE1 subunits are encoded by one and three genes, respectively, in the Arabidopsis genome. The three paralogs genes SAEla, SAElbl, and SAElb2 are the result of two independent duplication events. Since SAElbl and SAElb2 correspond to two identical cop- ies, only two E1 small subunit isoforms are present in vivo: SAEla and SAElb. The E1 heterodimer nuclear localization is modulated by the C-terminal tail of the SAE2 subunit. In vitro, SUMO conjugation rate is dependent on the SAE1 isoform contained in the E1 holoenzyme and our results suggest that downstream steps to SUMO-E1 thioester bond formation are affected. In vivo, SAEla isoform deletion in T-DNA insertion mutant plants conferred sumoylation defects upon abi- otic stress, consistent with a sumoylation defective phenotype. Our results support previous data pointing to a regula- tory role of the E1 activating enzyme during SUMO conjugation and provide a novel mechanism to control sumoylation in vivo by diversification of the E1 small subunit.  相似文献   

20.
In order to investigate DNA methylation profiles of five pluripotency-related genes (Oct4, Sox2, Nanog, Rex1 and Fgf4) during bovine maternal to zygotic transition (MZT) in both in vitro fertilized (IVF) and nuclear transfer (NT) embryos, sodium bisulfite sequencing method was used to detect DNA methylation levels, accompanied by the statistical analysis of embryo developmental rates. The results showed that Oct4, Nanog, Rex1 and Fgf4 were respectively demethylated by 25.22% (P < 0.01), 3.84% (P > 0.05), 31.82% (P < 0.01) and 10% (P > 0.05) while Sox2 retained unmethylation during MZT in IVF embryos. By contrast, Oct4 and Rex1 respectively underwent demethylation by 23.04% (P < 0.01) and 6.02% (P > 0.05), and, reversely, Sox2, Nanog and Fgf4 respectively experienced remethylation by 0.84% (P > 0.05), 5.39% (P > 0.05) and 5.46% (P > 0.05) during MZT in NT embryos. Interestingly, the CpG 14 site of Sox2 was specifically methylated in both 8-cell and morula NT embryos. In addition, the development of blastocysts between IVF and NT embryos showed no significant difference. DNA methylation analysis showed that only Oct4 and Sox2 underwent the correct methylation reprogramming process, which may be responsible for the development of blastocysts of NT embryos to a certain extent. In conclusion, the five genes respectively experienced demethylation to different extents and incomplete DNA methylation reprogramming during bovine MZT in both IVF and NT embryos, suggesting that they may be used as indicators for bovine embryo developmental competence.  相似文献   

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