共查询到20条相似文献,搜索用时 15 毫秒
1.
The building blocks fac-[99mTc{κ3-HB(timMe)3}(CO)3] and fac-[99mTc{κ3-R(μ-H)B(timMe)2}(CO)3] [R is H (4a), Ph (5a); timMe is 2-mercapto-1-methylimidazolyl] were obtained almost quantitatively by reacting fac-[99mTc(CO)3(H2O)3]+ with the corresponding scorpionate. These compounds cross the intact blood–brain barrier in mice, with significant retention in the case of 4a and 5a. Using 4a as the lead structure, we have synthesized the functionalized complexes fac-[M{κ3-H(μ-H)B(timBu-pip)2}(CO)3] [M is Re (8), 99mTc (8a); timBu-pip is methyl[4-((2-methoxyphenyl)-1-piperazinyl)butyl](2-mercapto-1-methylimidazol-5-yl)methanamide] and fac-[M{κ
3-H(μ-H)B(timMe)(timBu-pip)}(CO)3] [M is Re (9), 99mTc (9a)] and evaluated their potential as radioactive probes for the targeting of brain 5-HT1A serotonergic receptors. The Re complexes exhibit excellent affinity [IC50=0.172 ± 0.003 nM (8); IC50=0.65 ± 0.01 nM (9)] for the 5-HT1A receptor. The radioactive congeners (99mTc) have shown an initial brain uptake of 1.38 ± 0.46%ID g−1 (8a) and 0.43 ± 0.12%ID g−1 (9a), but suffer from a relatively fast washout. 相似文献
2.
The effect of ANG II on pHi, [Ca2+]i and cell volume was investigated in T84 cells, a cell line originated from colon epithelium, using the probes BCECF-AM, Fluo
4-AM and acridine orange, respectively. The recovery rate of pHi via the Na+/H+ exchanger was examined in the first 2 min following the acidification of pHi with a NH4Cl pulse. In the control situation, the pHi recovery rate was 0.118 ± 0.001 (n = 52) pH units/min and ANG II (10−12 M or 10−9 M) increased this value (by 106% or 32%, respectively) but ANG II (10−7 M) decreased it to 47%. The control [Ca2+]i was 99 ± 4 (n = 45) nM and ANG II increased this value in a dose-dependent manner. The ANG II effects on cell volume were minor and late
and should not interfere in the measurements of pHi recovery and [Ca2+]i. To document the signaling pathways in the hormonal effects we used: Staurosporine (a PKC inhibitor), W13 (a calcium-dependent
calmodulin antagonist), H89 (a PKA inhibitor) or Econazole (an inhibitor of cytochrome P450 epoxygenase). Our results indicate
that the biphasic effect of ANG II on Na+/H+ exchanger is a cAMP-independent mechanism and is the result of: 1) stimulation of the exchanger by PKC signaling pathway
activation (at 10−12 – 10−7 M ANG II) and by increases of [Ca2+]i in the lower range (at 10−12 M ANG II) and 2) inhibition of the exchanger at high [Ca2+]i levels (at 10−9 – 10−7 M ANG II) through cytochrome P450 epoxygenase-dependent metabolites of the arachidonic acid signaling pathway. 相似文献
3.
Elisa Palma Bruno L. Oliveira João D. G. Correia Lurdes Gano Leonor Maria Isabel C. Santos Isabel Santos 《Journal of biological inorganic chemistry》2007,12(5):667-679
Aiming to develop new bone-seeking radiotracers based on the organometallic core fac-[99mTc(CO)3]+ with improved radiochemical and biological properties, we have prepared new conjugates with phosphonate pendant groups. The
conjugates comprise a chelating unit for metal coordination, which corresponds to a pyrazolyl-containing backbone (pz) with
a N,N,N donor-atom set, and a pendant diethyl phosphonate (pz-MPOEt), phosphonic acid (pz-MPOH) or a bisphosphonic acid (pz-BPOH)
group for bone targeting. Reactions of the conjugates with the precursor [99mTc(H2O)3(CO)3]+ yielded (mote than 95%) the single and well-defined radioactive species [99mTc(CO)3(κ3-pz-MPOEt)]+ (1a), [99mTc(CO)3(κ3-pz-MPOH]+ (2a) and [99mTc(CO)3(κ3-pz-BPOH)]+ (3a), which were characterized by reversed-phase high-performance liquid chromatography . The corresponding Re surrogates (1–3), characterized by the usual analytical techniques, including X-ray diffraction analysis in the case of 1, allowed for macroscopic identification of the radioactive conjugates. These radioactive complexes revealed high stability
both in vitro (phosphate-buffered saline solution and human plasma) and in vivo, without any measurable decomposition. Biodistribution
studies of the complexes in mice indicated a fast rate of blood clearance and high rate of total radioactivity excretion,
occurring primarily through the renal–urinary pathway in the case of complex 3a. Despite presenting moderate bone uptake (3.04 ± 0.47% injected dose per gram of organ, 4 h after injection), the high stability
presented by 3a and its adequate in vivo pharmacokinetics encourages the search for new ligands with the same chelating unit and different
bisphosphonic acid pendant arms. 相似文献
4.
In an experimental site for reforestation of degraded area, three-year-old plants of Bertholletia excelsa Humb. & Bonpl. were subjected to different fertilization treatments: T0 = unfertilized control, T1 = green fertilization
(branches and leaves) and T2 = chemical fertilization. Higher net photosynthetic rates (P
N) were observed in T1 [13.2±1.0 μmol(CO2) m−2 s−1] compared to T2 [8.0±1.8 μmol(CO2) m−2 s−1] and T0 [4.8±1.3 μmol(CO2) m−2 s−1]. Stomatal conductance (g
s), transpiration rate (E) and water use efficiency (WUE) of individuals of T1 and T2 did not differ significantly, however, they were by 88, 55 and
63%, respectively, higher in T1 than in the control. The mean values of variable fluorescence (Fv), performance index (P.I.) and total chlorophyll [Chl (a+b)] were higher in T1. Our results indicate that green fertilization improves photosynthetic structure and function in plants
of B. excelsa in young phase. 相似文献
5.
trans -[PtCl4(NH3)(thiazole)] (1), trans-[PtCl4(cha)(NH3)] (2), cis-[PtCl4(cha)(NH3)] (3) (cha =cyclohexylamine), and cis-[PtCl4(NH3)2] (4) has been investigatedat 25 °C in a 1.0 M aqueous medium at pH 2.0–5.0 (1) and 4.5–6.8 (2–4) using stopped-flow spectrophotometry. The redox reactions follow the second-order rate law , where k is a pH-dependent rate constant and [GSH]tot the total concentration of glutathione. The reduction takes place via parallel reactions between the platinum(IV) complexes
and the various protolytic species of glutathione. The pH dependence of the redox kinetics is ascribed to displacement of
these protolytic equilibria. The thiolate species GS− is the major reductant under the reaction conditions used. The second-order rate constants for reduction of compounds 1–4 by GS− are (1.43±0.01)×107, (3.86±0.03)×106, (1.83±0.01)×106, and (1.18±0.01)×106 M−1 s−1, respectively. Rate constants for reduction of 1 by the protonated species GSH are more than five orders of magnitude smaller. The mechanism for the reductive elimination
reactions of the Pt(IV) compounds is proposed to involve an attack by glutathione on one of the mutually trans coordinated chloride ligands, leading to two-electron transfer via a chloride-bridged activated complex. The kinetics results
together with literature data indicate that platinum(IV) complexes with a trans Cl-Pt-Cl axis are reduced rapidly by glutathione as well as by ascorbate. In agreement with this observation, cytotoxicity
profiles for such complexes are very similar to those for the corresponding platinum(II) product complexes. The rapid reduction
within 1 s of the platinum(IV) compounds with a trans Cl-Pt-Cl axis to their platinum(II) analogs does not seem to support the strategy of using kinetic inertness as a parameter
to increase anticancer activity, at least for this class of compounds.
Received: 8 December 1999 / Accepted: 15 February 2000 相似文献
6.
By means of microcalorimetry, the effect of four copper(II) complexes on Tetrahymena growth was investigated. The extent and duration of the inhibitory effect on the metabolism, judged by the rate constant,
k, and the half inhibition concentration, IC50, varied with the different complexes. The results showed that the half inhibition concentrations IC50 of CuCl2, (C9H6NO)2Cu and [Cu(phen)2]Cl2⋅6H2O were 9.9 × 10−4, 2.0 × 10−4, and 2.6 × 10−4 mol/L, respectively. The sequence of antibiotic activity of these three complexes was: (C9H6NO)2Cu > [Cu(phen)2]Cl2⋅6H2O > CuCl2. The growth rate constants of [Cu(phen)3]Cl2⋅6H2O did not change obviously with the increase of concentrations, but [Cu(phen)3]Cl2⋅6H2O also can prolong the time of Tetrahymena growth. 相似文献
7.
Savignan F Ballion B Odessa MF Charveron M Bordat P Dufy B 《Journal of biomedical science》2004,11(5):671-682
We have used the human calcium- and temperature-dependent (HaCaT) keratinocyte cell line to elucidate mechanisms of switching from a proliferating to a differentiating state. When grown in low calcium medium (<0.1 mM) HaCaT cells proliferate. However, an increase in the calcium concentration of the culture medium, [Ca2+]0, induces growth arrest and the cells start to differentiate. Numerous studies have already shown that the increase in [Ca2+]0 results in acute and sustained increases in intracellular calcium concentration, [Ca2+]i. We find that the Ca2+-induced cell differentiation of HaCaT cells is also accompanied by a significant decrease in mitochondrial membrane potential, DeltaPsi. By combining patch-clamp electrophysiological recordings and microspectrofluorimetric measurements of DeltaPsi on single cells, we show that the increase in [Ca2+]i led to DeltaPsi depolarization. In addition, we report that tetraethylammonium (TEA), a blocker of plasma membrane K+ channels, which is known to inhibit cell proliferation, and 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), a blocker of plasma membrane Cl– channels, also affect DeltaPsi. Both these agents stimulate HaCaT cell differentiation. These data therefore strongly suggest a direct causal relationship between depolarization of DeltaPsi and the inhibition of proliferation and induction of differentiation in HaCaT keratinocytes. 相似文献
8.
Effects of intracellular Mg2+ on a native Ca2+-and voltage-sensitive large-conductance K+ channel in cultured human renal proximal tubule cells were examined with the patch-clamp technique in the inside-out mode.
At an intracellular concentration of Ca2+ ([Ca2+]i) of 10−5–10−4 M, addition of 1–10 mM Mg2+ increased the open probability (Po) of the channel, which shifted the Po –membrane potential (Vm) relationship to the negative voltage direction without causing an appreciable change in the gating charge (Boltzmann constant).
However, the Mg2+-induced increase in Po was suppressed at a relatively low [Ca2+]i (10−5.5–10−6 M). Dwell-time histograms have revealed that addition of Mg2+ mainly increased Po by extending open times at 10−5 M Ca2+ and extending both open and closed times simultaneously at 10−5.5 M Ca2+. Since our data showed that raising the [Ca2+]i from 10−5 to 10−4 M increased Po mainly by shortening the closed time, extension of the closed time at 10−5.5 M Ca2+ would result from the Mg2+-inhibited Ca2+-dependent activation. At a constant Vm, adding Mg2+ enhanced the sigmoidicity of the Po–[Ca2+]i relationship with an increase in the Hill coefficient. These results suggest that the major action of Mg2+ on this channel is to elevate Po by lengthening the open time, while extension of the closed time at a relatively low [Ca2+]i results from a lowering of the sensitivity to Ca2+ of the channel by Mg2+, which causes the increase in the Hill coefficient.
M. Kubokawa and Y. Sohma contributed equally to this work. 相似文献
9.
The morphological, anatomical and physiological variations of leaf traits were analysed during Quercus ilex L. leaf expansion. The leaf water content (LWC), leaf area relative growth rate (RGRl) and leaf dry mass relative growth rate (RGRm) were the highest (76±2 %, 0.413 cm2 cm−2 d−1, 0.709 mg mg−1 d−1, respectively) at the beginning of the leaf expansion process (7 days after bud break). Leaf expansion lasted 84±2 days when
air temperature ranged from 13.3±0.8 to 27.6±0.9 °C. The net photosynthetic rate (P
N), stomatal conductance (g
s), and chlorophyll content per fresh mass (Chl) increased during leaf expansion, having the highest values [12.62±1.64 μmol
(CO2) m−2 s−1, 0.090 mol (H2O) m−2 s−1, and 1.03±0.08 mg g−1, respectively] 56 days after bud break. Chl was directly correlated with leaf dry mass (DM) and P
N. The thickness of palisade parenchyma contributed to the total leaf thickness (263.1±1.5 μm) by 47 %, spongy layer thickness
38 %, adaxial epidermis and cuticle thickness 9 %, and abaxial epidermis and cuticle thickness 6 %. Variation in leaf size
during leaf expansion might be attributed to a combination of cells density and length, and it is confirmed by the significant
(p<0.001) correlations among these traits. Q. ilex leaves reached 90 % of their definitive structure before the most severe drought period (beginning of June — end of August).
The high leaf mass area (LMA, 15.1±0.6 mg cm−2) at full leaf expansion was indicative of compact leaves (2028±100 cells mm−2). Air temperature increasing might shorten the favourable period for leaf expansion, thus changing the final amount of biomass
per unit leaf area of Q. ilex. 相似文献
10.
Willis CK Turbill C Geiser F 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2005,175(7):479-486
Data on thermal energetics for vespertilionid bats are under-represented in the literature relative to their abundance, as
are data for bats of very small body mass. Therefore, we studied torpor use and thermal energetics in one of the smallest
(4 g) Australian vespertilionids, Vespadelus vulturnus. We used open-flow respirometry to quantify temporal patterns of torpor use, upper and lower critical temperatures (T
uc and T
lc) of the thermoneutral zone (TNZ), basal metabolic rate (BMR), resting metabolic rate (RMR), torpid metabolic rate (TMR),
and wet thermal conductance (C
wet) over a range of ambient temperatures (T
a). We also measured body temperature (T
b) during torpor and normothermia. Bats showed a high proclivity for torpor and typically aroused only for brief periods. The
TNZ ranged from 27.6°C to 33.3°C. Within the TNZ T
b was 33.3±0.4°C and BMR was 1.02±0.29 mlO2 g−1 h−1 (5.60±1.65 mW g−1) at a mean body mass of 4.0±0.69 g, which is 55 % of that predicted for a 4 g bat. Minimum TMR of torpid bats was 0.014±0.006 mlO2 g−1 h−1 (0.079±0.032 mW g−1) at T
a=4.6±0.4°C and T
b=7.5±1.9. T
lc and C
wet of normothermic bats were both lower than that predicted for a 4 g bat, which indicates that V. vulturnus is adapted to minimising heat loss at low T
a. Our findings support the hypothesis that vespertilionid bats have evolved energy-conserving physiological traits, such as
low BMR and proclivity for torpor. 相似文献
11.
Aporn Bualuang Kanteera Soontharapirakkul Aran Incharoensakdi 《Journal of applied phycology》2010,22(2):123-129
The activity of Na+/H+ exchanger to remove toxic Na+ is important for growth of organisms under high salinity. In this study, the halotolerant cyanobacterium Aphanothece halophytica was shown to possess Na+/H+ exchange activity since exogenously added Na+ could dissipate a pre-formed pH gradient, and decrease extracellular pH. Kinetic analysis yielded apparent K
m (Na+) and V
max of 20.7 ± 3.1 mM and 3,333 ± 370 nmol H+ min−1 mg−1, respectively. For cells grown under salt-stress condition, the apparent K
m (Na+) and V
max was 18.3 ± 3.5 mM and 3,703 ± 350 nmol H+ min−1 mg−1, respectively. Three cations with decreasing efficiency namely Li+, Ca2+, and K+ were also able to dissipate pH gradient. Only marginal exchange activity was observed for Mg2+. The exchange activity was strongly inhibited by Na+-gradient dissipators, monensin, and sodium ionophore as well as by CCCP, a protonophore. A. halophytica showed high Na+/H+ exchange activity at neutral and alkaline pH up to pH 10. Cells grown at pH 7.6 under high salinity exhibited higher Na+/H+ exchange activity than those grown under low salinity during 15 days of growth suggesting a role of Na+/H+ exchanger for salt tolerance in A. halophytica. Cells grown at alkaline pH of 9.0 also exhibited a progressive increase of Na+/H+ exchange activity during 15 days of growth. 相似文献
12.
Antarctic marine organisms are considered to have extremely limited ability to respond to environmental temperature change.
However, here we show that the Antarctic notothenioid fish Pagothenia borchgrevinki is an exception to this theory. P. borchgrevinki was able to acclimate its resting metabolic rate and resting ventilation frequency after a 5°C rise in temperature. Acute
exposure to 4°C resulted in an elevation in metabolic rate (57.8 ± 4.79 mg O2 kg−1 h−1) and resting ventilation rate (40.38 ± 1.61 breaths min−1) compared with fish at −1°C (metabolic rate 34.45 ± 3.12 mg O2 kg−1 h−1; ventilation rate 29.88 ± 3.72 breaths min−1). However, after a 1-month acclimation period, there was no significant difference in the metabolic rate (cold fish 29.52 ± 3.01;
warm fish 31.13 ± 2.30 mg O2 kg−1 h−1), or the resting ventilation rate (cold fish 28.75 ± 0.98; warm fish 34.25 ± 2.28 breaths min−1) of cold and warm acclimated fish. Acclimation changes to the rate of oxygen consumption following exhaustive exercise were
complex. The pattern of oxygen consumption during recovery from exhaustive exercise was not significantly different in either
cold or warm acclimated fish. 相似文献
13.
The growth and production of the Baltic clam Macoma balthica in the southeastern part of the Baltic Sea were studied. The shell length of M. balthica reached 23.5 mm, the maximum age was 13+ years. The linear growth was described by the von Bertalanffy equation for shallow-water
area (depths 9–40 m): L
τ = 23.99(1 − e
−0.1293(τ − (−0.9578))), and for the deep-water area (41–81 m): L
τ = 20.61(1 − e
−0.1813(τ − (−0.5608))). The annual production was lower (25.35 ± 1.72 kJ/m2) in the shallow-water area than in the deep-water area (71.23 ± 4.48 kJ/m2), with values of P
s
/B ratio 0.44 and 0.38, respectively. 相似文献
14.
Diurnal and seasonal trends in net photosynthetic rate (P
N), stomatal conductance (g), transpiration rate (E), vapour pressure deficit, temperature, photosynthetic photon flux density, and water use efficiency (WUE) were compared
in a two-year-old Dalbergia sissoo and Hardwickia binata plantation. Mean daily maximum P
N in D. sissoo ranged from 21.40±2.60 μmol m−2 s−1 in rainy season I to 13.21±2.64 μmol m−2 s−1 in summer whereas in H. binata it was 20.04±1.20 μmol m−2 s−1 in summer and 13.64±0.16 μmol m−2 s−1 in winter. There was a linear relationship between daily maximum P
N and g
s in D. sissoo but there was no strong linear relationship between P
N and g
s in H. binata. In D. sissoo, the reduction in g
s led to a reduction in both P
N and E enabling the maintenance of WUE during dry season thereby managing unfavourable environmental conditions efficiently whereas
in H. binata, an increase in g
s causes an increase of P
N and E with a significant moderate WUE. 相似文献
15.
K+-conductive pathways were evaluated in isolated surface and crypt colonic cells, by measuring 86Rb efflux. In crypt cells, basal K+ efflux (rate constant: 0.24 ± 0.044 min−1, span: 24 ± 1.3%) was inhibited by 30 mM TEA and 5 mM Ba2+ in an additive way, suggesting the existence of two different conductive pathways. Basal efflux was insensitive to apamin,
iberiotoxin, charybdotoxin and clotrimazole. Ionomycin (5 μM) stimulated K+ efflux, increasing the rate constant to 0.65 ± 0.007 min−1 and the span to 83 ± 3.2%. Ionomycin-induced K+ efflux was inhibited by clotrimazole (IC50 of 25 ± 0.4 μM) and charybdotoxin (IC50 of 65 ± 5.0 nM) and was insensitive to TEA, Ba2+, apamin and iberiotoxin, suggesting that this conductive pathway is related to the Ca2+-activated intermediate-conductance K+ channels (IKca). Absence of extracellular Ca2+ did neither affect basal nor ionomycin-induced K+ efflux. However, intracellular Ca2+ depletion totally inhibited the ionomycin-induced K+ efflux, indicating that the activation of these K+ channels mainly depends on intracellular calcium liberation. K+ efflux was stimulated by intracellular Ca2+ with an EC50 of 1.1 ± 0.04 μM. In surface cells, K+ efflux (rate constant: 0.17 ± 0.027 min−1; span: 25 ± 3.4%) was insensitive to TEA and Ba2+. However, ionomycin induced K+ efflux with characteristics identical to that observed in crypt cells. In conclusion, both surface and crypt cells present
IKCa channels but only crypt cells have TEA- and Ba2+-sensitive conductive pathways, which would determine their participation in colonic K+ secretion. 相似文献
16.
17.
Supplementation with CaCl2·2H2O (50 mg l−1) or CuSO4·5H2O (10 mg l−1) improved mannitol production by Candida magnoliae by 14.5 and 18.6% (25 and 32 g/L), respectively. When used in combination, they acted synergistically: Ca2+ decreased the intracellular concentration of mannitol 30%, whereas Cu2+ increased the intracellular activity of mannitol dehydrogenase 1.6-times more than control. Ca2+ probably works by altering the permeability of cells to mannitol, whereas, Cu2+ increases the activity of an enzyme responsible for mannitol biosynthesis. 相似文献
18.
Oladele Samuel Ajayi 《Radiation and environmental biophysics》2009,48(3):323-332
Activity concentrations of the selected radionuclides 40K, 226Ra and 232Th were measured in surface soil samples collected from 38 cities in the southwest region of Nigeria by means of gamma spectroscopy
with a high-purity germanium detector. Measured activity concentration values of 40K varied from 34.9 ± 4.4 to 1,358.6 ± 28.5 Bq kg−1 (given on a dry mass (DM) basis) with a mean value of 286.5 ± 308.5 Bq kg−1; that of 226Ra varied from 9.3 ± 3.7 to 198.1 ± 13.8 Bq kg−1 with a mean value of 54.5 Bq kg−1 and a standard deviation of 38.7 Bq kg−1, while that of 232Th varied from 5.4 ± 1.1 to 502.0 ± 16.5 Bq kg−1 with a mean value of 91.1 Bq kg−1 and standard deviation of 100.9 Bq kg−1. The mean activity concentration values obtained for 226Ra and 232Th are greater than the world average values reported by the United Nations Scientific Committee on Effects of Atomic Radiation
for areas of normal background radiation. Radiological indices were estimated for the radiation/health hazards of the natural
radioactivity of all soil samples. Estimated absorbed dose rates in air varied from 12.42 ± 2.25 to 451.33 ± 19.06 nGy h−1, annual outdoor effective dose rates from 0.015 ± 0.003 to 0.554 ± 0.023 mSv year−1, internal hazard index from 0.10 ± 0.03 to 3.02 ± 0.16, external hazard index from 0.07 ± 0.01 to 2.60 ± 0.11, representative
level index from 0.19 ± 0.03 to 6.84 ± 0.29, activity index from 0.09 ± 0.02 to 3.42 ± 0.15, and radium equivalent activity
from 26.95 ± 5.04 to 963.15 ± 41.87 Bq kg−1. Only the mean value of the representative level index exceeds the limit for areas of normal background radiation. All other
indices show mean values that are lower than the recommended limits. 相似文献
19.
The main target of this work is to examine blood clearance and external exposure for 177Lu-DOTATATE compared with new emerging 177Lu-PSMA therapy. Blood clearance and radiation exposure of 31 patients treated with 5.5?±?1.1 GBq 177Lu-DOTATATE were compared to those of 23 patients treated with 7.4 GBq 177Lu-PSMA. Dose rates were measured at several distances and time points up to 120 h after treatment. Blood samples were collected conjunctively after infusion. Caregiver’s cumulative dose was measured by means of an OSL (optically stimulated luminescence) dosimeter for 4–5 days and medical staff’s dose was also estimated using electronic personal dosimeters. Finger dose was determined via ring TLD (Thermoluminescence Dosimeter) for radiopharmacists and nurses. Dose rates due to 177Lu-DOTATATE at a distance of 1 m, 4 h and 6 h after infusion, were 3.0?±?2.8 and 2?±?1.9 µSv/(h GBq), respectively, while those due to 177Lu-PSMA were 3.1?±?0.8 and 2.2?±?0.9 µSv/(h GBq). Total effective dose of 17 caregivers was 100–200 µSv for 177Lu-DOTATATE therapy. Mean effective doses to nurses and radiopharmacists were 5 and 4 µSv per patient, respectively, while those for physicists and physicians were 2 µSv per patient. For 177Lu-DOTATATE, effective half-life in blood and early elimination phase were 0.31?±?0.13 and 4.5?±?1 h, while they were found as 0.4?±?0.1 and 5?±?1 h, respectively, for 177Lu-PSMA. The first micturition time following 177Lu-DOTATATE infusion was noted after 36?±?14 min, while the second and third voiding times were after 74?±?9 and 128?±?41 min, respectively. It is concluded that blood clearance and radiation exposure for 177Lu-DOTATATE are very similar to those for 177Lu-PSMA, and both treatment modalities are reasonably reliable for outpatient treatment, since the mean dose rate [2.1 µSv/(h GBq)] decreased below the dose rate that allows release of the patient from the hospital (20 µSv/h) after 6 h at 1 m distance. 相似文献
20.
Long LH Liu J Liu RL Wang F Hu ZL Xie N Fu H Chen JG 《Cellular and molecular neurobiology》2009,29(1):7-15
Methionine and cysteine residues in proteins are the major targets of reactive oxygen species (ROS). The present work was
designed to characterize the impact of methionine and cysteine oxidation upon [Ca2+]i in hippocampal neurons. We investigated the effects of H2O2 and chloramine T(Ch-T) agents known to oxidize both cysteine and methionine residues, and 5, 5′-dithio-bis (2-nitrobenzoic
acid) (DTNB)—a cysteine-specific oxidant, on the intracellular calcium in hippocampal neurons. The results showed that these
three oxidants, 1 mM H2O2, 1 mM Ch-T, and 500 μM DTNB, induced an sustained elevation of [Ca2+]i by 76.1 ± 3.9%, 86.5 ± 5.0%, and 24.4 ± 3.2% over the basal level, respectively. The elevation induced by H2O2 and Ch-T was significantly higher than DTNB. Pretreatment with reductant DTT at 1 mM for 10 min completely prevented the
action of DTNB on [Ca2+]i, but only partially reduced the effects of H2O2 and Ch-T on [Ca2+]i, the reductions were 44.6 ± 4.2% and 29.6 ± 6.1% over baseline, respectively. The elevation of [Ca2+]i induced by H2O2 and Ch-T after pretreatment with DTT were statistically higher than that induced by single administration of DTNB. Further
investigation showed that the elevation of [Ca2+]i mainly resulted from internal calcium stores. From our data, we propose that methionine oxidation plays an important role
in the regulation of intracellular calcium and this regulation may mainly be due to internal calcium stores. 相似文献