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1.
Dietary copper deficiency was produced in Swiss albino mice and Sprague Dawley rats to determine the organ specificity of alterations in norepinephrine (NE) and dopamine (DA) concentrations and the relationship with organ copper levels. A 5-week dietary treatment was used, which started 1 week after birth for mice, initially via dams, and 3 weeks after birth for rats. Mice offspring (6 weeks of age) and rats (8 weeks of age) maintained on a copper-deficient (-Cu) treatment were compared with copper-adequate (+Cu) controls. Compared with +Cu animals, -Cu mice and rats were anemic and had low (<1% of +Cu) ceruloplasmin activities but normal body weights. The -Cu mice had organ copper concentrations ranging between 30% and 65% of +Cu values for eight organs studied, with the thymus being the least depleted. For -Cu rats, the range was 15% to 65%. Significant reductions in NE concentration were observed in the heart, pancreas, and spleen of -Cu mice. Elevated DA levels were observed in all organs except the brain. For -Cu rats, the NE level was lower in the heart and the DA level was higher in both the heart and spleen compared with +Cu rats. Dopamine elevation in the heart and spleen for both -Cu mice and rats was four- and fivefold higher, respectively. Adrenal catecholamine levels were only slightly changed by copper deficiency in mice or rats. Urinary levels of both NE and DA were higher in -Cu rats and mice. Plasma and heart tyrosine levels were not altered in -Cu mice. Elevated DA in -Cu rodents may be due to limiting dopamine-beta-monooxygenase. Higher urinary NE and lower organ NE may be due to a combination of decreased synthesis and enhanced turnover. The magnitude of decreased organ copper was not predictive of altered catecholamine pool size.  相似文献   

2.
Dietary copper (Cu) deficiency was produced in Swiss albino mice to determine the temporal relationship between depletion of Cu and changes in the cardiovascular and nervous system. Dams were placed on a Cu-deficient diet 4 days after parturition. Half the dams were provided with deionized water and their offspring are referred to as Cu-deficient (-Cu). Half the dams were given cupric sulfate in their drinking water (20 microg Cu/mL) and their offspring are referred to as Cu-adequate (+Cu). At 6 weeks of age a sample of the -Cu mice were repleted with CuSO(4). Mice were sampled 1 day after birth and at weekly intervals for 7 weeks. Both +Cu and -Cu mice grew at the same rate: birth weight increased 16-fold at 6 weeks of age. Liver Cu more than doubled between 1 and 7 days of age. At 2 weeks of age -Cu mice were anemic (lower hematocrit and hemoglobin) and had lower liver Cu and plasma ceruloplasmin activity compared to +Cu mice. Liver Fe was not elevated in -Cu mice until 2 weeks after anemia developed. At weaning first signs of altered catecholamine metabolism included elevation of dopamine in both heart and spleen. Norepinephrine concentrations and content, in contrast, were not both lowered in -Cu mice until 5 weeks of age. Heart weight was first elevated in -Cu mice at 6 weeks of age and relative weight (mg/g body wt) at 4 weeks of age. Liver Cu concentration was lower in 1-week repleted mice than in +Cu mice. Anemia preceded the development of cardiac hypertrophy and altered catecholamine levels in -Cu mice.  相似文献   

3.
Weanling albino male mice rapidly develop biochemical signs of copper deficiency when fed a purified diet containing 0.5 mg Cu/kg. Plasma ceruloplasmin activity of copper-deficient (-Cu) mice was 5% of that of copper-adequate (+Cu) control mice after only 3 d on the diet. More gradual loss of organ (liver, spleen, and thymus) cytochrome c oxidase activity was observed during the next 4 wk. Body weight was equivalent between +Cu and -Cu mice, but thymus weight dropped faster in -Cu mice than +Cu mice. The number of antibody producing cells to sheep erythrocytes was lower in -Cu mice compared to +Cu mice after 17 d on the diet. Spleen cytochrome oxidase activity of -Cu mice was 50% of that of +Cu mice by 10 d on the diet. Mitogenic response of splenic and thymic lymphocytes to concanavalin A (con A) was not greatly different between +Cu and -Cu mice. Splenocytes from -Cu mice had a 3-fold higher thymidine incorporation rate in the absence of mitogen compared to +Cu mice. The depressed antibody and high mitogenic background responses of -Cu mice were similar to previous work with another strain (C58) of mice that had been started on copper-deficient treatment from birth. However, the normal proliferative response to con A stimulation in postweaning copper deficiency differs from the previous model. Mice of both studies were very copper-deficient as judged by liver copper levels. Timing of the copper-deficient treatment influences the manner in which copper deficiency alters the immune response.  相似文献   

4.
Experiments performed with Holtzman rats demonstrated that brain iron (Fe) was lower by postnatal day 13 (P13) in pups born and nursed by dams that began copper-deficient (-Cu) treatment at embryonic day 7. Transcardial perfusion of P24-P26 males and females to remove blood Fe contamination revealed that brain Fe was still 20% lower in -Cu than +Cu rats. Estimated blood content of brain for -Cu rats was greater than for +Cu rats; for all groups, values ranged between 0.43 and 1.03%. Using group-specific data and regression analyses, r = 0.99, relating blood Fe to hemoglobin, brain Fe in non-perfused rats in a replicate study was lower by 33% at P13 and 39% at P24 in -Cu rats. Brain extracts from these rats and from P50 rats from a post-weaning model were compared by immunoblotting for transferrin receptor (TfR1). P24 brain -Cu/+Cu TfR1 was 3.08, suggesting that brains of -Cu rats were indeed Fe deficient. This ratio in P13 rats was 1.44, p < 0.05. No change in P50 -Cu rat brain TfR1 or Fe content was detected despite a 50% reduction in plasma Fe. The results suggest that brain Fe accumulation depends on adequate Cu nutriture during perinatal development.  相似文献   

5.
Copper deficiency was studied in mice to investigate an interaction between copper and ascorbic acid. Twelve-day-old mutant brindled mice that exhibited signs of copper deficiency were compared to their normal brothers as well as to age-matched suckling mice that were copper deficient (-Cu) because their dams were consuming a copper-deficient diet throughout gestation and lactation, and a fourth group of copper-supplemented ( + Cu) suckling mice that served as dietary controls. Dietary copper deficiency was also produced in older mice by beginning the treatment at birth and continuing for 7 wk. Organ ascorbate levels were determined by high performance liquid chromatography with electrochemical detection. Differences caused by diet and genetics were evident but age-dependent. Compared to controls, liver and kidney ascorbate levels did not change remarkably in young or old copper-deficient mice. Cardiac ascorbate levels were higher in 7-wk-old - Cu mice and lower in 12-d-old - Cu mice, despite hypertrophy in both cases. Spleen ascorbate levels were lower in older -Cu mice and higher in 12-d-old mice, but total spleen ascorbate reflected the hypertrophic and atrophic size in the older and younger -Cu mice, respectively. Brindled mutants had an extremely low level of ascorbate in spleen. Plasma ascorbate was lower in 7-wk-old - Cu mice. Reasons for the alterations in ascorbate levels are not known. Synthesis in liver from D-glucuronate was not altered by dietary copper deficiency in 7-wk-old mice. Synthesis was lower in livers from 12-d-old - Cu and brindled mice compared to control values. However, the difference correlated better with body weight of the mice rather than with degree of copper deficiency. Consequences of the altered organ levels of ascorbate in copper-deficient mice are not completely known.  相似文献   

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7.
This work investigates the effects of maternal adrenalectomy (ADX) on the development of the adrenal medulla. Adrenal catecholamines (AC) were measured at postnatal day (PN) 1, 8, 12 and 22 in rat offspring of ADX dams and in pups of control dams. The pups of ADX rats showed a reduction in AC concentrations in the adrenal medulla at PN 1, 12 and 22, although these were higher than in the pups of sham dams at PN 8. Further, in the pups of control mothers, there was an increase in ACs during the first two weeks of life whereas pups of ADX mothers only showed increases in noradrenaline, dopamine and adrenaline levels at day 8. These results suggest that maternal absence of corticosterone affects the medulla catecholamine content during development. These data support the idea that a maternal glucocorticoids are involved in the differentiation or/and maturation of the adrenal medulla.  相似文献   

8.
Scavenger receptor BI (SR-BI) mediates selective uptake of high density lipoprotein (HDL) cholesteryl ester in the liver and adrenal gland. Adrenal SR-BI is increased both in adrenocorticotropic hormone (ACTH)-treated mice and also in apolipoprotein A-I knock-out (apoA-I0) mice which have depleted adrenal cholesterol stores. The goal of the present study was to determine whether adrenal cholesterol stores and ACTH have independent effects on SR-BI expression in adrenal gland. Adrenal SR-BI levels were 5-fold higher in apoA-I0 than wild-type mice when killed under low stress condition, and plasma ACTH levels were similar in both strains. After male apoA-I0 or wild-type mice were treated with dexamethasone to suppress ACTH release, adrenal SR-BI protein levels were decreased in both groups but remained 13-fold higher in apoA-I0 than in wild-type mice. By contrast, uncontrolled stress or supplemental ACTH treatment increased SR-BI levels but narrowed the difference in SR-BI expression between apoA-I0 and wild-type. Cholesterol depletion by beta-cyclodextrin in cultured Y1-BS1 adrenal cells also led to a rapid 2- to 3-fold increase in SR-BI mRNA and protein levels, in association with a significant depletion of cellular free cholesterol.These results indicate that depletion of adrenal cholesterol stores can act independently from ACTH to increase SR-BI expression, but in vivo this effect is diminished under high ACTH conditions. Both stimuli may increase selective uptake via increased SR-BI as a means of replenishing cholesterol stores for steroid hormone synthesis.  相似文献   

9.
Nicotine treatment and copper (Cu) deficiency have been associated with an increased production of reactive oxygen species that may contribute to the development and/or progression of cardiovascular diseases (CVD). The present study investigated the influence of dietary Cu intake on the response to chronic nicotine treatment in spontaneous hypertensive rats (SHR) with respect to tissue trace mineral levels, several components of the oxidant defense system, and lipid peroxidation rates. SHR weighing 100–110 g were fed a Cu deficient diet (?Cu) (0.5 μg Cu/g) for 14 d prior to nicotine treatment. SHR were inserted with tablets that released nicotine at a rate of 75 μg/h or placebo (control). Following tablet insertion, rats were fed a control diet (+Cu) (12.0 μg Cu/g) or the ?Cu diet. Nicotine treatment lasted for 12 wk. Blood pressure (BP) was higher in nicotine-treated SHR than in control SHR at wk 3; BP was unaffected by diet. BP was higher in +Cu nicotine-treated SHR at wk 6 compared to ?Cu nicotine and control rats. BP was not affected by nicotine or diet at wk 2. Liver, heart, and brain Cu levels and liver, heart, and red cell CuZn superoxide dismutase and plasma ceruloplasmin oxidase activities were lower in the ?Cu SHR than in the +Cu SHR. Liver Fe levels were higher and plasma Fe levels were lower in the ?Cu rats than in the +Cu rats. Liver selenium-dependent-glutathione peroxidase (Se-GSH-Px) activity was lower in the ?Cu rats than in the +Cu rats; heart and thoracic aorta Se-GSH-Px activity was unaffected by ?Cu diet. Thoracic aorta, liver, and heart GSH-reductase activities were unaffected by treatments. Plasma thiobarbituric acid reactive substances (TBARS) were higher in the ?Cu than in the +Cu SHR. Liver and heart TBARS production was similar among the groups. These data show that nicotine can exacerbate the development of high BP in susceptible individuals; Cu deficiency did not exacerbate the effects of nicotine.  相似文献   

10.
Abstract: Perinatal copper deficiency was studied in 1-month-old female and male Sprague-Dawley rat offspring to investigate regional changes in brain copper and catecholamine levels. Offspring of dams given the low copper treatment beginning at day 7 of gestation exhibited signs characteristic of deficiency such as impaired growth and 10-fold lower liver copper levels compared with copper-adequate controls. Regional analysis of brain copper by graphite furnace atomic absorption spectroscopy revealed uniform and severe reduction of copper to levels 20 ± 3% of controls in all regions, except the hypothalamus, where reductions to 56 and 28% of those in copper-adequate females and males, respectively, were measured. HPLC analysis revealed significant reductions in norepinephrine levels in cerebrum, midbrain, corpus striatum, cerebellum, and medulla-pons of copper-deficient offspring ranging between 39 and 67% of control values. There were no significant differences in norepinephrine concentration in the hypothalamus. There was a significant, one-third reduction of dopamine in the corpus striatum of copper-deficient male rats. Consistent with altered in vivo dopamine β-monooxygenase activity, there were five-, three-, and twofold elevations of dopamine in cerebellum, medulla-pons, and hypothalamus of copper-deficient rats. Spectrophotometric measurement of in vitro dopamine β-monooxygenase activity of brain and adrenal homogenates was higher in copper-deficient rats, confirming prior work. An explanation for the in vitro data is unclear. Changes in copper and catecholamine levels were influenced by diet and were regionally selective, especially in the hypothalamus.  相似文献   

11.
Several neurochemical parameters were studied in brain regions of rats chronically treated with a high concentration of manganese chloride (20 mg MnCl2.4H2O per ml. of drinking water) throughout development until adulthood. Large increases in Mn accumulation were found in all brain regions (hypothalamus, +530%; striatum, +479%; other regions, +152 to +250%) of Mn-treated adult rats. In these animals, Ca levels were decreased (–20 to –46%) in cerebellum, hypothalamus, and cerebral cortex but were increased (+186%) in midbrain. Mg levels were decreased (–12 to –32%) in pons and medulla, midbrain, and cerebellum. Fe levels were increased (+95%) in striatum but were decreased (–28%) in cerebral cortex. Cu levels were increased (+43 to +100%) in pons and medulla and striatum but Zn levels were decreased (–30%) in pons and medulla. Na levels were increased (+22%) in striatum but those of K and Cl remained unchanged. Type A monoamine oxidase activities were decreased (–13 to –16%) in midbrain, striatum, and cerebral cortex, but type B monoamine oxidase activities decreased (–13%) only in hypothalamus. Acetylcholinesterase activities were increased (+20 to +22%) in striatum and cerebellum. The results are consistent with out hypothesis that chronic manganese encephalopathy not only affects brain metabolism of Mn but also that of other metals.We dedicate this paper to Professor Alan N. Davison. Professor Davison has conducted pioneering research in several important areas including: brain development and myelination, aging and Alzheimer's disease, and multiple sclerosis. He encouraged us to investigate the neurochemical mechanisms of neurotoxicity of metal ions, particularly in connection with neurological diseases. His encouragement and continued support facilitated the launching of our multidisciplinary research program in the long-term effects of manganese toxicity on brain development and aging.  相似文献   

12.
采用逆转录-聚合酶链式反应检测了慢性足底电击结合噪声应激致高血压大鼠下丘脑、延髓、中脑、垂体和肾上腺等组织中编码肾上腺髓质素的肾上腺髓质素前肽原(preproadrenomedullin,ppADM)基因以及ADM的特异性受体组件降钙素受体样受体(calcitonin-receptor-like receptor,CRLR)和受体活性调节蛋白2和3(receptor-activty-modifying proteins,RAMP2和RAMP3)表达的变化.我们观察到:与对照组相比,以3-磷酸甘油醛脱氢酶作为内参照,15 d足底电击结合噪声应激引起下丘脑、垂体和肾上腺中ppADM mRNA表达上调,而在延髓和中脑表达明显下调(P<0.01或P<0.05);CRLR基因表达量正常时在下丘脑相对较高,应激15 d后CRLR表达在延髓、中脑和下丘脑下调(P<0.01或P<0.05),而在垂体和肾上腺的表达无明显变化;应激后RAMP2基因在延髓和下丘脑表达上调,而在肾上腺表达显著下调(P<0.01),其他部位无明显变化;RAMP3基因在对照组大鼠的中脑和下丘脑表达较高,在应激性高血压大鼠的下丘脑和垂体表达上调(P<0.01或P<0.05),而在中脑和肾上腺表达下调(P<0.05),在延髓中的表达变化无统计学差异.上述结果提示:慢性足底电击结合噪声应激引起明显的中枢和下丘脑-垂体-肾上腺轴ADM及其受体组件CRLR/RAMP2或CRLR/RAMP3基因的表达变化.但慢性应激后中枢源性ADM及其受体的表达变化对应激和血压的调节以及在应激致高血压中的确切作用及机制尚待进一步研究.  相似文献   

13.
Li X  Li L  Shen LL  Qian Y  Cao YX  Zhu DN 《生理学报》2004,56(6):723-729
采用逆转录- 聚合酶链式反应检测了慢性足底电击结合噪声应激致高血压大鼠下丘脑、延髓、中脑、垂体和肾上腺等组织中编码肾上腺髓质素的肾上腺髓质素前肽原(preproadrenomedullin, ppADM) 基因以及ADM 的特异性受体组件降钙素受体样受体(calcitonin-receptor-like receptor,CRLR)和受体活性调节蛋白2 和3(receptor-activity-modifying proteins, RAMP2 和RAMP3)表达的变化。我们观察到:与对照组相比,以 3- 磷酸甘油醛脱氢酶作为内参照,15 d 足底电击结合噪声应激引起下丘脑、垂体和肾上腺中ppADM mRNA表达上调,而在延髓和中脑表达明显下调(P<0.01 或 P<0.05); CRLR基因表达量正常时在下丘脑相对较高,应激15 d 后CRLR 表达在延髓、中脑和下丘脑下调(P<0.01 或 P<0.05), 而在垂体和肾上腺的表达无明显变化;应激后RAMP2 基因在延髓和下丘脑表达上调,而在肾上腺表达显著下调(P <0.01), 其他部位无明显变化;RAMP3 基因在对照组大鼠的中脑和下丘脑表达较高,在应激性高血压大鼠的下丘脑和垂体表达上调(P<0.01 或P<0.05), 而在中脑和肾上腺表达下调(P<0.05), 在延髓中的表达变化无统计学差异。上述结果提示:慢性足底电击结合噪声应激引起明显的中枢和下丘脑- 垂体-肾上腺轴ADM 及其受体组件CRLR/RAMP2 或CRLR/R  相似文献   

14.
Change in cerebellar protein kinase C gamma (PKCgamma) content caused by perinatal copper (Cu) deficiency was determined in 22-day old rats. The offspring of dams with low Cu intake during gestation and lactation exhibited signs characteristic of Cu deficiency including anemia, greater than 90% reduction in liver Cu concentration, and undetectable serum ceruloplasmin. In addition, brain Cu concentrations were reduced 80%. No differences in the signs of Cu deficiency were observed between female and male offspring. However, cerebellar PKCgamma content was reduced 54% (P < 0.05, Tukey's test) in female offspring but only 18% (P > 0.05) in male offspring. Following 6 weeks of Cu supplementation, brain Cu concentrations remained depressed in female and male rats that experienced perinatal Cu deficiency, but cerebellar PKCgamma content was completely restored to control levels. Postnatal expression of PKCgamma in the cerebellum coincides with and regulates cerebellar maturation. The results of the present study indicate perinatal Cu deficiency may impair cerebellar maturation to a greater extent in females than in males. However, it is not clear whether suppression of PKCgamma by perinatal Cu deficiency produces permanent neuropathology in the cerebellum because the effects were reversed by Cu supplementation.  相似文献   

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Levels of ascorbic acid (AA) in the plasma, brain, and adrenal gland of rats were determined after 15 min of hypoxia (PaO2 less than 25 mm Hg) and following asphyxia. In rabbits, AA plasma levels were followed up to 75 min of reoxygenation following 15 min of hypoxia of the same severity. A significant increase (approximately 70%) in AA levels was found in plasma of rats and rabbits after hypoxia and asphyxia. This increase was found to be transient, with a return to normal levels within 1 h after resumption of normal oxygenation. Pretreatment with dexamethasone reduced the increase in AA level in both rabbits and rats. Adrenalectomy in rats, performed 24 h before the experiment, abolished the response to hypoxia. Ascorbate levels in the cerebral cortex, hypothalamus, and adrenal gland of awake rats subjected to hypoxia or asphyxia were found to be the same as in normoxic rats. Our results suggest that the observed changes in plasma AA levels are probably mediated through adrenocorticotropic hormone and that the adrenal gland is the major source of ascorbate efflux into the circulation during oxygen deprivation.  相似文献   

18.
We examined the effect of angiotensin I (AI), without the effect of angiotensin II (AII) converted from AI, on the weight of the adrenal glands, adrenal corticosterone (B) and adrenal aldosterone under conditions where the renin-angiotensin system was suppressed, since a reduction in the size of the adrenal glands is often observed in DOCA/salt hypertensive rats. Sixty male Wistar rats fed on a 1% NaCl solution were divided into 6 groups as follows: a) Salt group: received sesame oil and vehicle, b) Salt + C group: received sesame oil and MK422 (0.14 mg/day), an angiotensin converting enzyme inhibitor (CEI), c) DOCA group: received DOCA (30 mg/week) and vehicle, d) DOCA + A group: received DOCA and AI (0.5 mg/kg/day), e) DOCA + A + C group: received DOCA and AI with MK422, and f) DOCA + C group: received DOCA and MK422. After 4 weeks, the rats were sacrificed to sample their blood and remove their adrenal glands. There was no significant difference in adrenal B among the groups apart from the DOCA + C group. Adrenal aldosterone was lower in the groups of DOCA/salt hypertensive rats than in the Salt group and Salt + C group. Furthermore, the DOCA + A + C group and DOCA + C group had lower adrenal aldosterone levels than the DOCA group and DOCA + A group.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
Recent immunohistochemical characterization of the copper transport protein, Ctr1, reported enriched levels in mouse choroid plexus, and enhancement by copper deficiency. To extend and confirm this, experiments were conducted with Holtzman rats. Following perinatal copper deficiency there was an 80% reduction in brain copper of 24-27 day old copper-deficient (Cu-) rat pups compared to copper-adequate (Cu+) controls. Choroid plexus immunoblot analysis with rabbit anti-hCtr1 demonstrated a 50% higher Ctr1 protein expression in Cu-samples. However, levels of copper chaperone for superoxide dismutase (CCS) were unchanged, suggesting that Ctr1 buffers the choroid plexus against copper deficiency, since CCS normally is much higher in Cu-tissues. There were 13% lower levels of cytochrome c oxidase subunit IV (COX IV) detected in Cuchoroid plexus. In contrast, in cerebellum of Cu-rats CCS was 2-fold higher and COXIV 1.7-fold lower than Cu+ rats consistent with severe copper deficiency. Brain mitochondria from Cu-rats had severe reductions in COXIV content and CCO activity and modest but significant elevations in CCS and reductions in Cu, Zn-superoxide dismutase. COXIV may be a more sensitive marker for copper deficiency than CCS and may prove useful to assess copper status.  相似文献   

20.
We hypothesized that resveratrol, a natural phytoalexin found in grapes, can prevent oxidative stress, obesity and its related disturbances in obese rats programmed by early weaning. Lactating Wistar rats were separated into two groups: early weaning (EW) — dams who were wrapped with a bandage to interrupt the lactation in the last 3 days of lactation; control — dams whose pups had free access to milk during all lactation. At the 150th day, EW offspring were randomly subdivided into EW+resveratrol (EW+Res) — resveratrol (30 mg/kg/day); EW+vehicle (EW) — rats that received 0.5% (w/v) aqueous methylcellulose. The control group received vehicle. Rats were treated by gavage daily for 30 days. EW offspring developed hyperphagia, higher body weight, visceral obesity, higher systolic (SBP) and diastolic blood pressure (DBP) (+15% and +20%, respectively; P<.05) and higher serum triglycerides (TG) and low-density lipoprotein but lower high-density lipoprotein (+55%, +33% and ?13%, respectively; P<.05). Resveratrol normalized food intake, SBP and DBP and prevented obesity and dyslipidemia in EW+Res. EW rats had higher plasma and liver thiobarbituric-acid-reactive substances (TBARS) and lower plasma superoxide dismutase (SOD) and liver glutathione peroxidase activities (+51%, +18%, ?58%, ?31%, respectively; P<.05), and resveratrol normalized both plasma and liver TBARS and increased the activity of SOD and catalase in plasma. EW rats presented liver steatosis and higher liver TG, and resveratrol prevented these hepatic alterations. In conclusion, this study demonstrated a potential therapeutic use of resveratrol in preventing obesity and oxidative stress and reducing the risk of hypertension, dyslipidemia and steatosis in adult rats programmed by early weaning.  相似文献   

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