Gentamicin-Induced Chronotoxicity: Use of Body Temperature as a Orcadian Marker Rhythm

Aminoglycoside antibiotics produce varying degrees of ototoxicity, dependent on dosage time, in animals synchronized for rhythm study. Herein, we illustrate the use of an economical and reliable system to telemeter body temperature of laboratory animals as an endogenous marker rhythm for gentamicin-induxed ototoxicity. Two groups of 3 male Sprague-Dawley rats (250-400 gm) were housed in separate cages in a temperature-controlled room programmed with a 12:12 LD schedule and monitored for hearing thresholds at the frequencies of 8kHz, 16kHz, 24kHz and 32kHz at 2-week intervals. Each rat was dosed with 100 mg/kg/day gentamicin subcutaneously for a duration of 28 days. The animals from one group were dosed at their daily temperature maximum, while the animals of the other group were dosed at their daily temperature minimum. Both after 14 and 28 days of gentamicin treatment there was no important changes in auditory thresholds from baseline values when treatment was timed daily to the circadian peak of body temperature. Animals dosed daily at the trough of the circadian temperature rhythm evidenced an auditory threshold shift of between 5 and 25 dB after 14 days of treatment and a total hearing loss (80-90 dB) after 28 days of such treatment. These results document a dramatically greater level of hearing loss induced in those animals dosed with gentamicin at the body temperature trough (diurnal rest span) as compared to those dosed at the acrophase (nocturnal activity span). The findings indicate that the peak and trough of the circadian pattern of body temperature serve as meaningful markers of the resistance and susceptibility, respectively, of gentamicin-induced ototoxicity in rodent models.     

Gentamicin-Induced Chronotoxicity: Use of Body Temperature as a Orcadian Marker Rhythm

Aminoglycoside antibiotics produce varying degrees of ototoxicity, dependent on dosage time, in animals synchronized for rhythm study. Herein, we illustrate the use of an economical and reliable system to telemeter body temperature of laboratory animals as an endogenous marker rhythm for gentamicin-induxed ototoxicity. Two groups of 3 male Sprague-Dawley rats (250–400 gm) were housed in separate cages in a temperature-controlled room programmed with a 12:12 LD schedule and monitored for hearing thresholds at the frequencies of 8kHz, 16kHz, 24kHz and 32kHz at 2-week intervals. Each rat was dosed with 100 mg/kg/day gentamicin subcutaneously for a duration of 28 days. The animals from one group were dosed at their daily temperature maximum, while the animals of the other group were dosed at their daily temperature minimum. Both after 14 and 28 days of gentamicin treatment there was no important changes in auditory thresholds from baseline values when treatment was timed daily to the circadian peak of body temperature. Animals dosed daily at the trough of the circadian temperature rhythm evidenced an auditory threshold shift of between 5 and 25 dB after 14 days of treatment and a total hearing loss (80–90 dB) after 28 days of such treatment. These results document a dramatically greater level of hearing loss induced in those animals dosed with gentamicin at the body temperature trough (diurnal rest span) as compared to those dosed at the acrophase (nocturnal activity span). The findings indicate that the peak and trough of the circadian pattern of body temperature serve as meaningful markers of the resistance and susceptibility, respectively, of gentamicin-induced ototoxicity in rodent models.     

Chronopharmacokinetics and Chronotoxicity of Lithium in Mice Eating Normal and Low-Sodium Diets

The temporal aspects of the pharmacokinetics and toxicity of lithium were studied in mice eating normal and low-sodium diets. ICR male mice, housed under a lightrdark (LD; 12:12) cycle, were injected with variable doses of lithium chloride i.p. A circadian rhythm was found in lithium clearance after a single administration in mice eating the normal diet showed the maximum value in the early dark phase and the minimum in the early light phase. The repeated administration of lithium did not affect the rhythm of the pharmacokinetics of the drug under the LD cycle. Although the low-sodium diet significantly decreased the lithium clearance, it did not influence the rhythm of the clearance. Higher toxicity was demonstrated in mice injected with the drug at the time of day with lower lithium clearance in the single-dose study but not in the repeated-doses study, regardless of the diet conditions. The low-sodium diet increased the acute and chronic toxicity of lithium. The results indicate that there is a circadian rhythm of acute toxicity and clearance of lithium after a single dose or repeated administration of the drug in mice eating normal and low-sodium diets and that the low-sodium diet increases lithium toxicity by reducing the clearance of the drug without influencing the rhythm characteristics.     

经颅磁刺激联合丙戊酸钠注射液治疗癫痫持续状态的效果分析

目的:探讨经颅磁刺激(transcranial magnetic stimulate,TMS)联合丙戊酸钠注射液治疗癫痫持续状态的效果。方法:选择2014年8月到2017年8月在我院诊治的癫痫持续状态患者79例,根据治疗方法的不同分为观察组40例与对照组39例。对照组给予丙戊酸钠注射液治疗,观察组在对照组治疗的基础上给予经颅磁刺激治疗,两组均治疗1个月,比较其临床总有效率、治疗期间不良反应的发生情况及治疗前后低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、总胆固醇(TC)、甘油三酯(TG)水平、行为能力评分、被动肌动力评分及主动肌动力评分的变化。结果:观察组与对照组总有效率分别为97.5%和84.6%,观察组显著高于对照组(P0.05)。治疗期间,观察组食欲下降、恶心呕吐、嗜睡、头痛等不良反应发生率为10.0%,对照组为12.8%,两组对比无显著差异(P0.05)。治疗后,观察组TG、TC与LDL-C水平显著低于对照组(P0.05),两组HDL-C含量对比无显著差异(P0.05)。治疗后,观察组的行为能力评分、被动肌动力评分、主动肌动力评分都高于对照组(P0.05)。结论:经颅磁刺激联合丙戊酸钠注射液治疗癫痫持续状态能显著提高治疗效果,改善患者的神经行为功能,且不会影响患者的血脂水平与增加不良反应。     

Chronopharmacokinetics and Chronotoxicity of Lithium in Mice Eating Normal and Low-Sodium Diets

The temporal aspects of the pharmacokinetics and toxicity of lithium were studied in mice eating normal and low-sodium diets. ICR male mice, housed under a lightrdark (LD; 12:12) cycle, were injected with variable doses of lithium chloride i.p. A circadian rhythm was found in lithium clearance after a single administration in mice eating the normal diet showed the maximum value in the early dark phase and the minimum in the early light phase. The repeated administration of lithium did not affect the rhythm of the pharmacokinetics of the drug under the LD cycle. Although the low-sodium diet significantly decreased the lithium clearance, it did not influence the rhythm of the clearance. Higher toxicity was demonstrated in mice injected with the drug at the time of day with lower lithium clearance in the single-dose study but not in the repeated-doses study, regardless of the diet conditions. The low-sodium diet increased the acute and chronic toxicity of lithium. The results indicate that there is a circadian rhythm of acute toxicity and clearance of lithium after a single dose or repeated administration of the drug in mice eating normal and low-sodium diets and that the low-sodium diet increases lithium toxicity by reducing the clearance of the drug without influencing the rhythm characteristics.     

蓝藻生物钟分子机理的研究进展

蓝藻是具有内源性生物钟的简单生物.虽然蓝藻生物钟具有跟真核生物同样的基础特征,但其相关基因和蛋白质与真核生物没有同源性.蓝藻生物钟的核心是kai基因簇及其编码的蛋白KaiA,KaiB和KaiC.这三种Kai蛋白相互作用调节KaiC的磷酸化状态,从而产生昼夜节律信息.KaiC的磷酸化循环是昼夜节律的起博器,调控包括kai基因在内的相关基因的节律性表达.组氨酸蛋白激酶的磷酸化传递可将环境信息输入和将节律信息输出生物钟核心.     

卡马西平与丙戊酸钠对儿童癫痫部分性发作脑电图的临床对照研究

目的:探究卡马西平与丙戊酸钠对儿童癫痫部分发作患儿发作脑电图影响,并实施组间对照研究。方法:选择2017年1月至2020年1月于我院接受治疗的81例癫痫部分性发作患儿为研究对象,按照其接受治疗的差异将其分为卡马西平组(40例)和丙戊酸钠组(41例),对比两组患儿接受药物治疗后脑电图以及脑电地形图变化情况。结果:(1)卡马西平组患儿接受治疗后脑电图检测显示间歇期痫样活动减少≥50%者占比高达67.50%(27/40),而丙戊酸钠组占比仅为43.90%(18/41),两组比较差异明显(P<0.05);(2)脑电背景活动变化比较显示,治疗后卡马西平组患儿α波无影响者占比65.00%,明显高于丙戊酸钠组36.59%,同时丙戊酸钠组患儿δ波数(20 s内)药物治疗后变化较卡马西平组更为明显;(3)脑电功率比较显示,卡马西平组患儿治疗后仅θ频段相对功率出现明显变化(P<0.05),但丙戊酸钠组患儿α频段相对功率、θ频段相对功率和θ频段绝对功率均出现明显变化(P<0.05)。结论:丙戊酸钠应用于儿童癫痫部分性发作时患儿脑电背景活动会明显变慢,甚至有出现间歇期痫样放电的风险,而卡马西平相对更为稳定,对患儿脑电图的影响更小,安全性更高。     

奥卡西平与丙戊酸钠对癫痫患者血液学指标、认识功能及生活质量的影响

目的:探讨奥卡西平与丙戊酸钠对癫痫患者血液学指标、认识功能及生活质量的影响。方法:将2015年6月至2017年5月我院接诊的癫痫患者98例纳入本研究,随机分为观察组(n=49)和对照组(n=49),对照组给予丙戊酸钠治疗。观察组给予奥卡西平治疗。比较两组同型半胱氨酸(Hcy)、不对称二甲基精氨酸(ADMA)水平、简明精神状态检查量表(MMSE)评分、癫痫患者生活质量量表(QOLIE)评分,并比较两组不良反应发生情况。结果:治疗后两组患者Hcy、ADMA水平均高于治疗前,差异有统计学意义(P0.05),但治疗前和治疗后两组患者Hcy、ADMA水平组间比较差异均无统计学意义(P0.05)。观察组治疗后MMSE评分高于治疗前和对照组(P0.05);对照组治疗前后MMSE评分对比,差异无统计学意义(P0.05)。两组患者治疗后QOLIE各项评分高于治疗前(P0.05),观察组治疗后精力/疲乏、认知功能、药物影响等评分以及总评分高于对照组(P0.05)。观察组不良反应发生率为4.08%,与对照组的10.20%比较差异无统计学意义(P0.05)。结论:奥卡西平与丙戊酸钠治疗癫痫患者均可升高其Hcy、ADMA水平,无严重不良反应发生,而奥卡西平在改善癫痫患者的认知功能和生活质量等方面优于丙戊酸钠。     

Sodium valproate inhibits glucose transport and exacerbates Glut1-deficiency in vitro

Anticonvulsant sodium valproate interferes with brain glucose metabolism. The mechanism underlying such metabolic disturbance is unclear. We tested the hypothesis that sodium valproate interferes with cellular glucose transport with a focus on Glut1 since glucose transport across the blood-brain barrier relies on this transporter. Cell types enriched with Glut1 expression including human erythrocytes, human skin fibroblasts, and rat astrocytes were used to study the effects of sodium valproate on glucose transport. Sodium valproate significantly inhibited Glut1 activity in normal and Glut1-deficient erythrocytes by 20%-30%, causing a corresponding reduction of Vmax of glucose transport. Similarly, in primary astrocytes as well as in normal and Glut1-deficient fibroblasts, sodium valproate inhibited glucose transport by 20%-40% (P < 0.05), accompanied by an up to 60% downregulation of GLUT1 mRNA expression (P < 0.05). In conclusion, sodium valproate inhibits glucose transport and exacerbates Glut1 deficiency in vitro. Our findings imply the importance of prudent use of sodium valproate for patients with compromised Glut1 function.     

果蝇昼夜节律的分子机制研究进展

果蝇由于遗传易操作性而成为一个研究昼夜节律分子机制的理想模式生物 . 到目前为止,通过遗传学和生物化学方法已经鉴定到 10 多个时钟基因 (clock genes) 和许多时钟相关基因,包括时钟输入基因和钟控基因 . 这些时钟基因以及它们的相应产物组成两个互相依赖的转录 / 翻译反馈环路,从而调节行为和生理的昼夜节律 . 果蝇这种核心钟的工作原理同样见于哺乳动物 .     

丙戊酸钠对抗鱼藤酮诱导的SH-SY5Y细胞损伤的线粒体机制

研究丙戊酸钠（sodiumvalproate,VPA）对抗鱼藤酮（Rotenone）诱导的SH-SY5Y细胞损伤的作用及线粒体机制。以l,10μmol／LVPA预处理SH－SY5Y细胞3h,再加入400nmol／LRotenone作用24h。MTT法检测与相差显微镜观察相结合,分析VPA对抗Rotenone损伤的作用;JC－1染色法与Mito－Tracker染色法分析线粒体膜电位及线粒体数量的变化;Clark氧电极法检测细胞呼吸功能;DCFH-DA探针法检测细胞中Ros的含量;并在离体线粒体上观察VPA对Ca^2＋诱导的线粒体肿胀的影响。结果发现,1,10p．mol／LVPA预处理SH．SY5Y细胞3h可对抗400nmol／LRotenoneI起的细胞损伤,并且可以提高损伤细胞中线粒体的膜电位,增加线粒体的数量,此外,还可以增强损伤细胞的呼吸功能,降低细胞中ROS的含量,但VPA并不能直接作用于离体的线粒体发挥神经保护作用。由此,VPA具有良好的神经保护作用,其机制与增强线粒体功能和数量、从而改善细胞功能有关,这为其应用于帕金森病的预防与治疗提供了实验依据。     

奥氮平与碳酸锂分别联合丙戊酸钠治疗双相障碍躁狂发作的临床疗效比较

目的：比较奥氮平与碳酸锂分别联合丙戊酸钠治疗双相障碍躁狂发作的临床疗效,探讨提高双相障碍躁狂发作临床疗效的药物治疗方案。方法：选择双相障碍躁狂发作患者90例,随机均分为A组与B组,A组给予奥氮平联合丙戊酸钠治疗,B组给予碳酸锂联合丙戊酸钠治疗,比较两组患者治疗第2周、第4周、第6周躁狂量表（BRMS）评分、副反应量表（TESS）评分和治疗第6周的临床疗效。结果：两组患者在上述方面比较,差异均具有统计学意义（P〈O．05）,A组临床疗效好于B组。结论：药物治疗双相障碍躁狂发作时,应选择奥氮平联合丙戊酸钠治疗方案,可提高临床疗效,减少用药后副反应。     

Effect of Isonicotinic Acid Hydrazide on Extracellular Amino Acids and Convulsions in the Rat: Reversal of Neurochemical and Behavioural Deficits by Sodium Valproate

Abstract: We have studied the effect of isonicotinic acid hydrazide (INH), a convulsant agent, on the extracellular levels of amino acids in the hippocampus, and the effect of sodium valproate (VPA) administration in INH-treated rats. INH (250 mg/kg) caused a rapid and sustained decrease in basal levels of GABA, and during this period convulsions of increasing severity were observed. Basal levels of glutamine, taurine, aspartate, and glutamate were unchanged by INH. When VPA was coadministered with INH, basal GABA levels were increased and no convulsions were observed. When transmitter release was evoked using 100 m M K⁺, the increase in dialysate GABA observed in INH-treated animals was less than that seen in controls and convulsions increased in frequency. K⁺-evoked release of glutamate and aspartate tended to be higher following INH treatment, and in the case of aspartate, this increase was significant. VPA reversed the changes in evoked release of glutamate and aspartate, and release of GABA was considerably greater than that seen in control or INH-treated rats. No drug effect on evoked changes in taurine or glutamine level was seen. These are the first data to show decreased extracellular GABA in conjunction with convulsions in freely moving animals in vivo.     

Circadian Phase Dependent Pharmacokinetics of Disopyramide in Mice

The focus of the reported work is investigation of disopyramide chronopharmacokinetics in the mouse. Different groups of male NMRI mice maintained under controlled environmental conditions (LD: 0600-1800) received a single intraperitoneal injection of disopyramide (30mg per kg of body weight) at one of four different fixed time points of a 24-h period, i.e. 1000, 1600, 2200 or 0400. Blood samples were taken 0.5,1,2,3,4 and 6 hr after drug administration and total and free plasma levels of disopyramide were measured by an immunoenzymatic method.

Our data showed statistically significant circadian rhythms in the following pharmacokinetic parameters: highest volume of distribution = 3.91 ± 0.211kg^-1 at 2200 (circadian amplitude, half the peak-to-trough difference relative to the 24-hr mean multiplied by 100, is 34%); highest area under concentration curves = 16.06 ± 1.03μgml^-1hr^-1 at 0400 (circadian amplitude = 43%) and highest clearance = 3.04 ± 0.191hr“kg”¹ at 2200 (circadian amplitude = 21%). Protein binding of the drug was shown to ^he circadian time dependent. Alpha and beta phase elimination half-lives were not found to be significantly circadian phase-dependent. Thus circadian changes in disopyramide clearance may represent circadian changes in the drug's volume of distribution.     

奥氮平与碳酸锂分别联合丙戊酸钠治疗双相障碍躁狂发作 的临床疗效比较

目的:比较奥氮平与碳酸锂分别联合丙戊酸钠治疗双相障碍躁狂发作的临床疗效,探讨提高双相障碍躁狂发作临床疗效的药物治疗方案。方法:选择双相障碍躁狂发作患者90例,随机均分为A组与B组,A组给予奥氮平联合丙戊酸钠治疗,B组给予碳酸锂联合丙戊酸钠治疗,比较两组患者治疗第2周、第4周、第6周躁狂量表(BRMS)评分、副反应量表(TESS)评分和治疗第6周的临床疗效。结果:两组患者在上述方面比较,差异均具有统计学意义(P<0.05),A组临床疗效好于B组。结论:药物治疗双相障碍躁狂发作时,应选择奥氮平联合丙戊酸钠治疗方案,可提高临床疗效,减少用药后副反应。     

托吡酯、卡马西平与丙戊酸钠治疗脑炎继发癫痫的疗效比较

目的:观察和比较托吡酯、卡马西平与丙戊酸钠对治疗脑炎继发癫痫的临床疗效及安全性。方法:选择2013年1月~2015年9月在我院进行诊治的脑炎继发癫痫患者80例,随机分为托吡酯组、卡马西平组和丙戊酸钠组,分别采用托吡酯、卡马西平与丙戊酸钠治疗,比较三组的治疗有效率、执行能力与视空间、命名、抽象、注意、定向、语言以及延迟回忆等认知功能评分及不良反应的发生情况。结果:托吡酯组的有效率最高,为80.65%(25/31),卡马西平组的有效率最低,为70.00%(21/30),但三组间有效率相比差异无统计学意义(P0.05)。治疗后,托吡酯组患者的执行能力与视空间、命名、抽象、注意、定向、语言以及延迟回忆等认知功能评分均明显高于卡马西平组和丙戊酸钠组(P0.05);托吡酯组的不良反应发生率(12.90%)明显低于卡马西平组(36.67%)和丙戊酸钠组的(29.62%)(P0.05)。结论:托吡酯、卡马西平以及丙戊酸钠治疗脑炎继发癫痫疗效相当,但托吡酯对患者认知功能损害最小,安全性最高。     

Photorefractoriness and Its Termination in the Subtropical House Sparrow, Passer Domesticus: Involvement of Circadian Rhythm

Groups of photorefractory female subtropical house sparrows, Passer domestkus, when treated with 6 weeks of a short photocycle (8L : 16D) showed significant ovarian growth on their return to a long photocycle (15L :9D). A 6-hr photophase coupled with scotophase of varying durations does not terminate the refractory period under photoperiod cycles of 12 (6L : 6D), 36 (6L :30D) and 60 (6L : S4D) hr but the refractory period is terminated by light-dark cycles of 24 (6L: 18D), 48 (6L :42D) and 72 (6L : 66D) hr. These results are consistent with the Biinning hypothesis of coincidence between endogenous photosensitive rhythmicity and environmental photoperiod timing that an endogenous circadian rhythm is involved in the maintenance and termination of photorefractoriness.     

Regional Effects of Sodium Valproate on Extracellular Concentrations of 5-Hydroxytryptamine, Dopamine, and Their Metabolites in the Rat Brain: An In Vivo Microdialysis Study

The effects of sodium valproate (VPA; 100, 200, and 400 mg/kg, i.p.) on ventral hippocampal and anterior caudate putamen extracellular levels of dopamine (DA) and 5-hydroxytryptamine (5-HT) were examined using in vivo microdialysis. VPA induced dose-related increases in dialysate DA, 3,4-dihydroxyphenylacetic acid, and 5-HT in the ventral hippocampus. Anterior caudate putamen dialysate 5-HT was also dose dependently elevated by the drug, whereas DA levels tended to decrease with increasing VPA dose. In contrast, VPA (200, 400, and 800 mg/kg, i.p.) produced no significant elevation of DA in posterior caudate putamen dialysates, although 5-HT levels were significantly elevated at the 400- and 800-mg/kg doses. In all three regions studied, dialysate concentrations of 5-hydroxyindoleacetic acid and homovanillic acid remained at basal levels following VPA treatments. The results are discussed with regard to the possible anticonvulsant mode of action of VPA.     

Role of Sleep Restriction in Daily Rhythms of Expression of Hypothalamic Core Clock Genes in Mice

Lack of sleep time is a menace to modern people, and it leads to chronic diseases and mental illnesses. Circadian processes control sleep, but little is known about how sleep affects the circadian system. Therefore, we performed a 28-day sleep restriction (SR) treatment in mice. Sleep restriction disrupted the clock genes’ circadian rhythm. The circadian rhythms of the Cry1 and Per1/2/3 genes disappeared. The acrophase of the clock genes (Bmal1, Clock, Rev-erbα, and Rorβ) that still had a circadian rhythm was advanced, while the acrophase of negative clock gene Cry2 was delayed. Clock genes’ upstream signals ERK and EIFs also had circadian rhythm disorders. Accompanied by changes in the central oscillator, the plasma output signal (melatonin, corticosterone, IL-6, and TNF-α) had an advanced acrophase. While the melatonin mesor was decreased, the corticosterone, IL-6, and TNF-α mesor was increased. Our results indicated that chronic sleep loss could disrupt the circadian rhythm of the central clock through ERK and EIFs and affect the output signal downstream of the core biological clock.     

丙戊酸钠联合奥卡西平治疗小儿癫痫的疗效及对患儿脑电图、认知功能和血清神经因子的影响

摘要 目的：评价丙戊酸钠联合奥卡西平治疗小儿癫痫的疗效及对患儿脑电图、认知功能和血清神经因子的影响。方法：选入2019年1月~2022年12月收治的癫痫患儿104例,根据治疗方法不同分为单药组（丙戊酸钠治疗）和联合组（丙戊酸钠+奥卡西平治疗）,各52例。评价两组的临床疗效、脑电图、认知功能、血清神经因子等指标,并进行统计比较。结果：联合组治疗后癫痫发作频率及每次持续时间显著低于单药组（P<0.05）,EEG显示痫样放电率、总异常亦明显低于单药组（P＜0.05）;联合组治疗总有效率94.23%,明显高于单药组的71.15%（P<0.05）;两组治疗后WISC-CR量表VIQ、PIQ和FIQ评分均较治疗前明显升高（P<0.05）,而联合组升高幅度更大,与单药组差异显著（P<0.05）;治疗前,两组血清BDNF、NSE和S-100β蛋白无明显差异（P＞0.05）,而治疗后,联合组血清BDNF水平明显高于单药组、NSE和S-100β水平显著低于单药组（P＜0.05）;两组不良反应总发生率无差异（P＞0.05）。结论：丙戊酸钠联合奥卡西平治疗小儿癫痫疗效较好,可有效缓解临床症状,控制脑部异常放电,改善认知功能,调节血清神经因子水平,且安全性良好。