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901.
The touchstone to evaluate accurately the aggressiveness and invasiveness of prostate cancer is something of a holy grail in the facet of urologic oncology. Gene expression and sequencing studies have improved our interpretations of the genetic determinants of the disease but are unsuccessful in the establishment of any unified classification to improve the molecular stratification. These questions addressing failure in rational drug design are difficult to answer in the multifaceted and heterogeneous pathogenesis of prostate cancer. In this review, we have developed a roadmap of the "recalcitrant prostate cancer proteome" to recognize the aspects of prostate cancer that may be helpful in effectively translating these findings to the clinic.  相似文献   
902.
The phytotoxic effects of lead (Pb) on seed germinability, seedling growth, photosynthetic performance, and nutrient accumulation (K(+) and Cu(2+)) in two maize genotypes (EV-1098 and EV-77) treated with varying levels of PbSO(4) (0.01, 0.1, and 1.0 mg L(-1)) were appraised in this study. In the seed germination experiment, lead stress significantly reduced seed germination percentage and index, plumule and radicle lengths as well as fresh and dry weights in both genotypes. In the second experiment, lengths and fresh and dry weights of shoots and roots decreased due to Pb in both genotypes with increase in plant age. Higher Pb levels also decreased photosynthetic rate (A), water use efficiency (A/E), and intrinsic water use efficiency (A/g(s)), but increased transpiration rate (E) and C(i)/C(a) ratio as a result of increase in stomatal conductance (g(s)). The concentrations of K(+) and Cu(2+) decreased in root, stem, and leaves of both genotypes, which could be a direct consequence of multifold increase in Pb concentration in these tissues. Overall, cv. EV-1098 had better Pb tolerance potential than EV-77 because the former genotype showed less reduction in seed germinability parameters, photosynthetic performance, and K(+) and Cu(2+) accumulation in shoot and root under lead stress.  相似文献   
903.
To assess the toxic effect of nickel (Ni) on the growth and some key metabolic processes in sunflower, varying levels of Ni as Ni(NO3)2 up to 60 mg L−1 were applied once to sunflower cultivars SF-187 and Hysun-33 at sowing time in sand culture. An increase in Ni in the growth medium adversely affected growth parameters, sugar concentration (both reducing and non-reducing), as well as the activities of α-amylase and protease. It also slowed down mobilization of stored proteins and amino acids in the germinating seeds. However, an increase in the activities of α-amylase and protease was observed over time from 24 to 120 h after sowing. Cultivar Hysun-33 showed better performance than SF-187 in the presence of excess Ni. Overall, Ni-induced reduction in germination of sunflower seed appeared to be due to disturbance in biochemical metabolism as the availability of sugars for the synthesis of metabolic energy as well as necessary amino acids for the synthesis of proteins and enzymes essential for the growing embryo are generally reduced due to suppression in α-amylase and protease activities.  相似文献   
904.
In the present study, the newly synthesized TRH analog (l-pGlu-(2-propyl)-l-His-l-ProNH2; NP-647) was evaluated for its effects in in vitro (oxygen glucose deprivation (OGD)-, glutamate- and H2O2-induced injury in PC-12 cells) and in vivo (transient global ischemia) models of cerebral ischemic injury. PC-12 cells were subjected to oxygen and glucose deprivation for 6 h. Exposure of NP-647 was given before and during OGD. In glutamate and H2O2 induced injury, exposure of NP-647 was given 1, 6 and 24 h prior to exposure of glutamate and H2O2 exposure. NP-647, per se found to be non-toxic in 1-100 μM concentrations. NP-647 showed protection against OGD at the 1 and 10 μM. The concentration-dependent protection was observed in H2O2- and glutamate-induced cellular injury. In in vivo studies, NP-647 treatment showed protection of hippocampal (CA1) neuronal damage in transient global ischemia in mice and subsequent improvement in memory retention was observed using passive avoidance retention test. Moreover, administration of NP-647 resulted in decrease in inflammatory cytokines TNF-α and IL-6 as well as lipid peroxidation. These results suggest potential of NP-647 in the treatment of cerebral ischemia and its neuroprotective effect may be attributed to reduction of excitotoxicity, oxidative stress and inflammation.  相似文献   
905.
Background information. AQPs (aquaporins) are water channel proteins that are expressed in almost all living things. In mammalians, 13 members of AQPs (AQP0–12) have been identified so far. AQP5 is known to be expressed mostly in the exocrine cells, including the salivary gland acinar cells. A naturally occurring point mutation (G308A, Gly103 > Asp103) was earlier found in the rat AQP5 gene [Murdiastuti, Purwanti, Karabasil, Li, Yao, Akamatsu, Kanamori and Hosoi (2006) Am. J. Physiol. 291 , G1081–G1088]; in this mutant, the rate of initial saliva secretion under stimulated and unstimulated conditions is less than that for the wt (wild‐type) animals. Results. Here the mutant molecule was characterized in detail. Using the Xenopus oocyte system, we demonstrated the mutant AQP5 to have water permeability almost the same as that of the wt molecule. Mutant and wt AQP5s, tagged with GFP (green fluorescent protein; GFP‐AQP5s) and expressed in polarized MDCK‐II (Madin—Darby canine kidney II) cells, first appeared in the vesicular structure(s) in the cytoplasm, and were translocated to the upper plasma membrane or apical membrane during cultivation, with the mutant GFP‐AQP5 being translocated less efficiently. Thapsigargin and H‐89 both induced translocation in vitro of either molecule, whereas colchicine inhibited this activity; the fraction of cells showing apical localization of mutant GFP‐AQP5 was less than that showing that of the wt molecule under any of the experimental conditions used. In the mutant SMG (submandibular gland) tissue, localization of AQP5 in the apical membrane of acinar cells was extremely reduced. Vesicular structures positive for AQP5 and present in the cytoplasm of the acinar cells were co‐localized with LAMP2 (lysosome‐associated membrane protein 2) or cathepsin D in the mutant gland, whereas such co‐localizations were very rare in the wt gland, suggesting that the mutant molecules largely entered lysosomes for degradation. Conclusion. Replacement of highly conserved hydrophobic Gly103 with strongly hydrophilic Asp103 in rat AQP5, though it did not affect water permeability, may possibly have resulted in less efficient membrane trafficking and increased lysosomal degradation, leading to its lower expression in the apical membrane of the acinar cells in the SMG.  相似文献   
906.
In eukaryotes, protein transport into the endoplasmic reticulum (ER) is facilitated by a protein-conducting channel, the Sec61 complex. The presence of large, water-filled pores with uncontrolled ion permeability, as formed by Sec61 complexes in the ER membrane, would seriously interfere with the regulated release of calcium from the ER lumen into the cytosol, an essential mechanism for intracellular signalling. We identified a calmodulin (CaM)-binding motif in the cytosolic N-terminus of mammalian Sec61α that bound CaM but not Ca2+-free apocalmodulin with nanomolar affinity and sequence specificity. In single-channel measurements, CaM potently mediated Sec61-channel closure in Ca2+-dependent manner. At the cellular level, two different CaM antagonists stimulated calcium release from the ER through Sec61 channels. However, protein transport into microsomes was not modulated by Ca2+-CaM. Molecular modelling of the ribosome/Sec61/CaM complexes supports the view that simultaneous ribosome and CaM binding to the Sec61 complex may be possible. Overall, CaM is involved in limiting Ca2+ leakage from the ER.  相似文献   
907.
The ameliorative role of 28-homobrassinolide under chilling stress in various growth, photosynthesis, enzymes and biochemical parameters of cucumber (Cucumis sativus L.) were investigated. Cucumber seedlings were sprayed with 0 (control), 10−8, or 10−6 M of 28-homobrassinolide at the 30-day stage. 48 h after treatment plants were exposed for 18 h to chilling temperature (10/8°C, 5/3°C). The most evident effect of chilling stress was the marked reduction in plant growth, chlorophyll (Chl) content, and net photosynthetic rate, efficiency of photosystem II and activities of nitrate reductase and carbonic anhydrase. Moreover, the activities of antioxidant enzymes; catalase (E.C. 1.11.1.6), peroxidase (E.C.1.11.1.7), superoxide dismutase (E.C. 1.15.1.1) along with the proline content in leaves of the cucumber seedlings increased in proportion to chilling temperature. The stressed seedlings of cucumber pretreated with 28-homobrassinolide maintained a higher value of antioxidant enzymes and proline content over the control suggesting the protective mechanism against the ill-effect caused by chilling stress might be operative through an improved antioxidant system. Furthermore, the protective role of 28-homobrassinolide was reflected in improved growth, water relations, photosynthesis and maximum quantum yield of photosystem II both in the presence and absence of chilling stress.  相似文献   
908.
The majority of true parasitoids manipulate their host’s physiology for their own benefit. In this study, we documented the physiological changes that occurred in major soldiers of the subterranean termite Macrotermes gilvus (Hagen) (Isoptera: Termitidae) parasitized by the koinobiont larval endoparasitoid Misotermes mindeni Disney and Neoh (Diptera: Phoridae). We compared the metabolic rate, body water content, body water loss rate, cuticular permeability, and desiccation tolerance between parasitized and unparasitized major soldiers. The metabolic rate of parasitized hosts was significantly higher than that of unparasitized termites. Mean total body water content of parasitized major soldiers (64.73 ± 3.26%) was significantly lower than that of unparasitized termites (71.99 ± 2.23%). Parasitized hosts also had significantly lower total body water loss rates (5.72 ± 0.06%/h) and higher cuticular permeability (49.37 ± 11.26 μg/cm/h/mmHg) than unparasitized major soldiers (6.75 ± 0.16%/h and 60.76 ± 24.98 μg/cm/h/mmHg, respectively). Parasitized major soldiers survived almost twice as long as unparasitized termites (LT50 = 6.66 h and LT50 = 3.40 h, respectively) and they had significantly higher tolerance to water loss compared to unparasitized termites (45.28 ± 6.79% and 32.84 ± 7.69%, respectively). Body lipid content in parasitized hosts (19.84 ± 6.27%) was significantly higher than that of unparasitized termites (6.17 ± 7.87%). Finally, parasitized hosts had a significantly lower percentage of cuticular water content than unparasitized major soldiers (10.97 ± 1.84% and 13.17 ± 2.21%, respectively). Based on these data, we conclude that the parasitism-induced physiological changes in the host are beneficial to the parasitoids as the alterations can clearly increase the parasite’s chances of survival when exposed to extreme environmental conditions and ensure that the parasitoids are able to complete their larval development successfully before the host dies.  相似文献   
909.
This study was undertaken to investigate the hematological and biochemical changes in experimentally infected goats with Besnoitia caprae from the time of infection till 360 days post-infection (PI). Six male goats were inoculated subcutaneously with 13 × 10(7) bradyzoites of B. caprae, and blood samples were collected from the jugular vein. The total erythrocyte and total leukocyte counts, hematocrit value, and differential leukocyte counts were determined. Serum biochemical analysis, including the total protein, albumin, total globulin, cholesterol, triglyceride, chloride, testosterone, calcium (Ca(2+)), inorganic phosphorus, sodium (Na(+)), potassium (K(+)), iron (Fe(2+)), glucose, serum amyloid A (SAA), haptoglobin (Hp), fibrinogen, ceruloplasmin, aspartate aminotransferase, alanine aminotransferase, creatine kinase, lactate dehydrogenase, and alkaline phosphatase, was undertaken. Skin biopsy from the limbs were collected at weekly intervals and histologically examined for Besnoitia cysts. Cysts were present in the skin biopsies of the leg of the infected goats from day 28 PI. There were variations in hematological analyses, but no significant difference was seen. From day 30 to 360 PI, results showed that SAA, Hp, fibrinogen, and ceruloplasmin concentrations increased, whereas testosterone concentrations decreased. Infected goats exhibited decrease of albumin and increase of serum total protein and globulin concentrations. By contrast, there were no significant differences in the remained analyses concentrations.  相似文献   
910.
Protein and DNA destabilization by osmolytes: the other side of the coin   总被引:1,自引:0,他引:1  
Singh LR  Poddar NK  Dar TA  Kumar R  Ahmad F 《Life sciences》2011,88(3-4):117-125
Osmolytes are naturally occurring small molecules accumulated intracellularly to protect organisms from various denaturing stresses. Similar to the two faces of a coin, several of these osmolytes are stabilizing and destabilizing proteins depending on the concentrations and/or solvent conditions. For example, the well known stabilizing osmolyte, trehalose destabilizes some proteins at high concentration and/or high pH. In spite of the fact that destabilizing aspects of osmolytes can modulate many cellular processes including regulation of protein homeostasis (proteostasis), protein-protein interaction, and protein-DNA interaction, researchers have mostly focused on the stabilizing aspects of osmolytes. Thus, it is important to look into both aspects of osmolytes to determine their precise role under physiological conditions. In this article, we have discussed both stabilizing and destabilizing/denaturant aspects of osmolytes to uncover both sides of the coin.  相似文献   
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