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71.
Serum leptin levels were significantly increased during rat gestation. Our data showed that leptin mRNA levels in both the adipose tissue and placenta were higher as pregnancy progressed, suggesting a role for both tissues in the hyperproduction of leptin. This paradoxical increase in leptin concentration during gestation suggests that a physiological state of leptin resistance may exist at the hypothalamic level that may explain the hyperphagia observed in pregnant rats. In order to study this issue further, levels of the mRNA encoding the different leptin receptor isoforms were determined in the hypothalamus of pregnant and nonpregnant rats. We found a specific reduction of the mRNA levels encoding the leptin receptor isoform Ob-Rb in the hypothalamus of pregnant rats compared to nonpregnant animals, suggesting that during pregnancy the hypothalamus shows a physiological resistance to the high levels of leptin due, at least in part, to a decrease in the expression of the long, biologically active form of the leptin receptor (Ob-Rb). During lactation, serum leptin levels returned to values observed in nonpregnant rats. In the hypothalami of these animals, Ob-Rb mRNA content was similar to that observed in nonpregnant rats, but we found an increased expression of some of the short forms of the leptin receptor (Ob-Re and Ob-Rf). This could contribute to induction of the hyperphagia present during lactation. These data provide new insights into the adaptive mechanisms that take place during pregnancy and lactation in order to meet increased metabolic requirements.  相似文献   
72.
Astaxanthin (ASX) is one of the keto-carotenoids, which is biologically more active than other counterparts. Besides its variety of beneficial effects, it was reported to exert anticancer effects. Despite its utilization against different cancer types, the effect of ASX on mesothelioma has yet to be well-studied. In this study, our goal is to ascertain how ASX will affect SPC212 human mesothelioma cells. First, the effective doses of ASX against SPC212 cells were investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Thereafter, with flow cytometry analysis, Annexin-V and caspase 3/7 assay were implemented for the evaluation of apoptotic cell death and an oxidative stress test was carried out to determine how the free radicals changed. Ultimately, the cells' morphology was examined under a light microscope. The effective doses of ASX were found as 50, 100, and 200 µM. In the Annexin V assay, the total apoptosis increased to around 12%, 30%, and 45% with increasing doses of ASX. In the caspase 3/7 assay, the total apoptosis was around 25% and 38% at 100 and 200 µM. In oxidative stress analysis, reactive oxygen species-positive cells rose from 4.54 at the lowest dose to 86.95 at the highest dose. In morphological analysis, cellular shrinkage, decrease in cell density, swelling and vacuolations in some cells, membrane blebbing, and apoptotic bodies are observed in ASX-treated cells. To conclude, the current study provided insights into the efficacy and effects of ASX against SPC212 mesothelioma cells regarding morphology, proliferation, and cell death for future studies.  相似文献   
73.

Key message

Anatomical characteristics and hydrologic signals in tree-rings of oaks from areas with regular flooding may vary, even within the same forest stand, and largely depend on the micro-environmental conditions.

Abstract

Q. robur decline in European floodplain forests in recent years seems to be strongly associated with the deteriorating hydrological regime. We investigated the influence of the Krka River flow on tree-ring patterns of Q. robur from the Krakovo floodplain forests (Slovenia) to assess the effect of micro-location conditions on hydrological signals in wood-anatomical characteristics. We selected two groups of Q. robur trees growing at nearby locations with different hydrological conditions, resulting in frequent autumn and spring flooding at the wetter site (=W oaks) but no flooding at the other, drier site (=D oaks). We found differences between the two groups in the anatomical structure of tree-rings; however, ring width proved to be the main variable determining the anatomical structure of oak wood. D and W oaks responded differently to the Krka River flow in the studied period. Radial growth of D oaks was negatively influenced by spring flow, but positively influenced by minimum summer flow. In W oaks, ring width was positively correlated with mean summer flow. Thus, environmental information stored in wood-anatomical features may vary, even within the same forest stand, and largely depends on the micro-environment. Reduced wood increments of D oaks suggest that growth conditions are less favourable, implying a link between the health state of oaks from lowland forest and hydrological conditions. Trees intended for hydrological reconstruction must therefore be carefully selected to avoid the possibility of error and potential loss of information. Anatomical characteristics and hydrological signals in tree-rings of oaks from areas with regular flooding may vary, even within the same forest stand, and largely depends on the micro-environmental conditions.  相似文献   
74.
Four isoenzymes of carbonic anhydrase (CA) were purified from Elephas Irogontherii (steppe elephant) bone (approx 0.3-0.5 million years old) from different locations (outer peripheral, cytosolic, inner peripheral and integral) using Sepharose 4B-L-tyrosine sulphanilamide affinity chromatography and their kinetics properties were investigated and compared with known CA isoenzymes. The purification degree of CAs was monitored by SDS-PAGE. Purification fold for outer peripheral, inner peripheral, cytosolic and integral CA was 395.6, 652.8, 1091 and 429.3 and the molecular mass (as determined by gel filtration chromatography) was 37, 36, 35, and 39 kDa, respectively. The optimal temperature for isozymes was 10-20, 30, 30 and 60 degrees C and optimal pH- was between 7.5-11, 7.5-10, 7.5-10 and 7.5 respectively. K(m) values (at optimum pH and 20 degrees C) for p-nitrophenyl acetate as substrate were 4.83, 6.80, 4.525 and 3.86 mM and the Vmax values for the same substrate were 0.00097, 0.0149, 0.00249 and 0.00072 micromol/L*min, respectively. I50 values of isoenzymes for the inhibitors of CA - sulphanilamide, KSCN, acetazolamide and NaN3 were also determined.  相似文献   
75.
Pheochromocytomas and sympathetic paragangliomas are rare tumours arising from chromaffin cells, producing catecholamines in various amounts. Fatal hypertensive episodes may occur perioperatively, which are preventable by alpha adrenergic receptor blockers. The perioperative mortality rate of diagnosed versus undiagnosed catecholamine-producing tumours is significant, considering that only a minority of tumours develop metastasis. Herein we describe a case of a primary adrenal pheochromocytoma referred to as a pancreatic tumour, successfully diagnosed by endoscopic ultrasound-guided fine needle aspiration biopsy, with a distinct morphology (prominent nuclear anisonucleosis, intranuclear pseudoinclusions, and multinucleation) and immunohistochemical signature.  相似文献   
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Many filamentous fungi produce an array of extracellular enzymes that acting in cell walls release elicitors of the plant defense response These enzymes may therefore be important in biocontrol applications. The aim of this study was to characterize extracellular degradative enzymes produced by a non-pathogenic binucleate isolate of Rhizoctonia AG-G. The fungus was grown in liquid culture supplemented with pectin, polygalacturonic acid or glucose as a carbon sources and filtrates of the culture media were analyzed for the detection of pectinolytic and glucan hydrolytic enzymes. Using only pectin as a carbon source, secretion of polygalacturonases and methylesterases was found. When the liquid medium was supplemented with polygalacturonic acid, only polygalacturonase activity was detected. However, when glucose was used as carbon source arge946.gif" alt="beta" align="MIDDLE" BORDER="0">-1,3 and arge946.gif" alt="beta" align="MIDDLE" BORDER="0">-1,6 glucanases activities were detected, using laminarin and pustulan as substrates, but none of the pectinolytic activities were found. These enzymes were partially purified and characterized. The arge946.gif" alt="beta" align="MIDDLE" BORDER="0">-(1,3)(1,6) glucanase and polygalacturonase enzymes showed to be active against cell wall polysaccharides from potato sprouts. These enzymes may have an important role in fungus-plant cell wall interaction. This is the first study about the production of extracellular enzymes by non-pathogenic binucleate Rhizoctonia AG-G.  相似文献   
80.
Diazepam is a benzodiazepine with anticonvulsant, anxiolytic, sedative and muscle-relaxing properties. Many aspects of its toxicity have been investigated, including genotoxic and carcinogenic effects in various model systems. However, it is still unclear whether diazepam is in fact a genotoxic agent. Propofol is a rapid-onset, short-acting intravenous anesthetic agent. It is used widely for the induction and maintenance of anesthesia as well as for long-term sedation in intensive care units. There is limited information in the literature on its genotoxic effects. Both drugs are commonly used as anesthetic in patients undergoing open-heart surgery. Therefore, we investigated the possible genotoxic effects of propofol and diazepam in those patients, using a chromosomal aberration (CA) assay. Peripheral blood samples were collected from 45 patients before induction of anesthesia and at the end of the anesthesia with diazepam or propofol. In Group I (n=24), anesthesia was induced with 0.2 mg kg(-1) diazepam and 10 microg kg(-1) fentanyl. In Group II (n=21), anesthesia was induced with 1 mg kg(-1) propofol and 10 microg kg(-1) fentanyl. Pancuronium bromide (0.1 mg kg(-1)) was administered for skeletal muscle relaxation in both groups. Anesthesia was maintained by diazepam administration at 5 mg kg(-1) in Group I or by continuous propofol administration at 2-4 mg (kg h)(-1) in Group II. All patients received 0.02 mg kg(-1) pancuronium and 5 microg kg(-1) fentanyl boluses at 30-40 min intervals for anesthesia maintenance. Body temperature was controlled during bypass in the two groups. We found that the mean frequency of CAs in both groups before and at the end of the anesthesia were not statistically significantly different. Our analysis also indicated that age, smoking habit and gender were not confounding factors. In conclusion, our results indicate that diazepam and propofol do not exert genotoxic effects in blood cells during open-heart surgery.  相似文献   
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