甲地孕酮在家兔和大鼠的药物动力学

用放射免疫法(RIA)测定甲地孕酮(MA)血清浓度并计算了在家兔和大鼠静注或口服的药物动力学参数。MA口服的生物利用度,家兔为64％,大鼠为56％。MA肝微粒体酶代谢实验提示有极性较MA为大的代谢产物形成,~3H-MA十二指肠给药后30min内门静脉血中放射性远高于外周血,也有极性代谢产物形成。     

Suitability of the AUC Ratio as an Indicator of the Pharmacokinetic Advantage in HIPEC

The purpose of this study was to evaluate the area under the concentration-time curve (AUC) ratio as an optimal indicator of the pharmacokinetic advantage during hyperthermic intraperitoneal perioperative chemotherapy. The impact on the AUC ratio on the variables related to the calculation of systemic drug exposure, instillation time, and peripheral drug distribution was evaluated through simulations as well as through a retrospective analysis of studies published in the literature. Both model simulations and the retrospective analysis showed that the 3 variables evaluated had an impact on the AUC ratio value if the complete systemic exposure was not fully considered. However, when that complete systemic exposure was considered, none of these variables affected the AUC ratio value. AUC ratio is not a characteristic parameter of a drug if the calculated systemic drug exposure is not complete. Thus, AUC ratio is not valid for comparing the pharmacokinetic advantage of 2 drugs, and it should not be employed to prove whether a drug can be used in hyperthermic intraperitoneal perioperative chemotherapy safely with regard to toxicity. As an alternative, the study of the absorption rate constant and the bioavailability are proposed as the true and independent parameters that reflect the amount of drug absorbed.     

Respiratory effects of buprenorphine/naloxone alone and in combination with diazepam in naive and tolerant rats

Respiratory depression has been attributed to buprenorphine (BUP) misuse or combination with benzodiazepines. BUP/naloxone (NLX) has been marketed as maintenance treatment, aiming at preventing opiate addicts from self-injecting crushed pills. However, to date, BUP/NLX benefits in comparison to BUP alone remain debated. We investigated the plethysmography effects of BUP/NLX in comparison to BUP/solvent administered by intravenous route in naive and BUP-tolerant Sprague-Dawley rats, and in combination with diazepam (DZP) or its solvent. In naive rats, BUP/NLX in comparison to BUP significantly increased respiratory frequency (f, P < 0.05) without altering minute volume (V_E). In combination to DZP, BUP/NLX significantly increased expiratory time (P < 0.01) and decreased f (P < 0.01), tidal volume (V_T, P < 0.001), and V_E (P < 0.001) while BUP only decreased V_T (P < 0.5). In BUP-tolerant rats, no significant differences in respiratory effects were observed between BUP/NLX and BUP. In contrast, in combination to DZP, BUP/NLX did not significantly alter the plethysmography parameters, while BUP increased inspiratory time (P < 0.001) and decreased f (P < 0.01) and V_E (P < 0.001). In conclusion, differences in respiratory effects between BUP/NLX and BUP are only significant in combination with DZP, with increased depression in naive rats but reduced depression in BUP-tolerant rats. However, BUP/NLX benefits in humans remain to be determined.     

莫西沙星注射液治疗急性细菌感染临床研究

目的以左氧氟沙星注射液为对照,采用随机对照、多中心、平行开放的实验设计,评价莫西沙星治疗敏感菌引起的临床感染的有效性和安全性。方法盐酸莫西沙星注射液用法用量为400mg,qd,静滴,乳酸左氧氟沙星注射液用法用量为400mg,qd,静滴,疗程均为7～14天。患者总例数为49例。结果试验组和对照组的临床有效率分别为96.30%和77.27%;不同菌种感染患者的临床有效率分别为95.65%和73.68%;细菌清除率分别为95.65%和78.95%;不良反应发生率分别为14.81%和27.27%。结论盐酸莫西沙星注射液是治疗临床感染安全有效的药物。     

Urocortin ameliorates diabetic nephropathy in obese db /db mice

Background and purpose: Hyperglycaemia induces overproduction of mitochondrial reactive oxygen species (ROS) in endothelial cells, which is believed to be a major molecular mechanism underlying complications of diabetes, including diabetic nephropathy. Impairment of endothelium-dependent vasodilatation is found in type 2 diabetes. Urocortin is a 40 amino-acid peptide related to the corticotrophin-releasing factor (CRF) family, which suppresses production of ROS in endothelial cells and sustains endothelium-dependent relaxations of rat coronary artery. However, it is not clear if urocortin has any effect on diabetic nephropathy. Experimental approach: Possible mechanisms underlying the effects of urocortin on diabetic nephropathy were investigated in db/db mice and cultured rat mesangial cells. Key results: Urocortin decreased body weight, plasma levels of advanced glycation end-prod ucts, blood urea nitrogen and creatinine levels. However, food intake, plasma insulin and glucose levels remained unaffected. Superoxide dismutase activity was increased markedly, whereas malonaldehyde levels in kidney homogenate and sorbitol concentrations in red blood cells were decreased significantly in urocortin-treated mice. Urocortin significantly decreased glomerular extracellular matrix expansion and accumulation in kidney. Moreover, urocortin inhibited the overexpression of transforming growth factor-beta 1 and connective tissue growth factor in rat mesangial cells induced by 25 mM glucose. All the effects of urocortin, except sorbitol accumulation, were abolished by the non-selective CRF receptor blocker, astressin. Conclusion and implications: Urocortin could significantly ameliorate diabetic nephropathy and this effect was mediated via the     

15例尿毒症患者应用rHuEpo的药代动力学研究

 报道了１５例尿毒症患者，ｉｖ和ｓｃｒＨｕＥｐｏ的药代动力学。用ＥＬＩＳＡ法测定血清ｒＨｕＥｐｏ浓度，用３Ｐ８７软件处理药浓度。时间数据。ｉｖ的药代动力学符合线性二室模型，其主要动力学参数Ｔ＿（１／２），Ｖ，Ｃｌ和ＡＵＣ＿（０～∞）分别为５．４５±１．４８ｈ，７９．７±５２．２ｍｌ／ｋｇ，０．３０５±０．２９８（ｍｌ·ｍｉｎ）／ｋｇ和５２９５．９±３６６１．２（ｍＵ·ｈ）／ｍｌ。ｓｃ的药代动力学符合线性一室模型，其主要的药代动力学参数Ｔ＿（ｍａｘ），Ｃ＿（ｍａｘ），Ｔ＿（１／２）和ＡＵＣ＿（０～∞）分别为１０．２±５．７ｈ，３７．２±１９．２ｍＵ／ｍｌ，１７．６±８．１ｈ和１６２０．３±８６０．７（ｍＵ·ｈ）／ｍｌ。单次ｓｃ后，血药浓度约为ｉｖ相同剂量时峰浓度的５％。占ｓｃ组５０％的患者，ｓｃ后约０．５ｈ才从血清中测到ｒＨｕＥｐｏ浓度。ｓｃ组较ｉｖ组浓度。时间曲线下总面积小。此外还比较了ｉｖ和ｓｃ的临床价值。     

Functional subsets of neurons in somatosensory thalamus of the cat

Functional properties of somatosensory thalamic neurons isolated within a region encompassing nucleus ventralis posterolateralis were studied in chloralose-anesthetized cats. A sample of these neurons responding to electrical stimulation of the contralateral forepaw was reconstructed by pooling data from 46 individual animals on the basis of unit spatial location. Seventy percent of the 640 neurons studied responded only to the contralateral forepaw; they had small receptive fields as determined by natural stimulation, generally on the digits and the dorsum of the paw, and 75% of this group were excited by light touch or deflection of hairs. Thirty percent of the neurons studied responded to the contralateral forepaw and to other limbs as well, their larger receptive fields often being bilateral. Approximately 50% of these wide-field neurons were excited by gentle mechanical stimulation. Some cells of this type were identified as projection neurons by virtue of their antidromic activation from the S I forepaw area of cerebral cortex. The wide-field neurons described here are not adequately explained as vestigial aberrations persisting at the feline stage in an evolutionary trend toward strictly somatotopic thalamic representation. Comparison of the dynamic response properties (latency, spikes per discharge, and frequency-following) of small- and wide-field somatosensory thalamic neurons suggests that they are activated via different input mechanisms and that each has a particular functional role in somesthesis.     

Wide-field conditioning effects on small-field neurons in the posterior sigmoid gyrus of domestic cats

Single neurons were isolated in four different recording sites in sensorimotor cortex of the domestic cat, all sites being topographically related to the contralateral forepaw. Conditioning-testing interactions were made on 409 small-field neurons, the testing input being the contralateral forepaw (also the ipsilateral forepaw in the case of bilateral-field neurons) and the conditioning input being any paw that was ineffective in exciting the neuron. About 29% of the neurons showed inhibitory interactions and 23% showed facilitatory interactions. Of these, about 5.5% showed both effects, according to the conditioning site. Nearly 54% of the neurons failed to show any interaction effects. Most of the latter were isolated in the two posterior recording sites, located in somatosensory area I; the interaction effects were found predominantly in the two anterior recording sites, located in agranular tissue. Neurons that responded only to contralateral forepaw stimulation (sa neurons) and showed facilitatory interactions from the other three paws had response properties characteristic of neurons that respond to all four paws (m neurons). The sa neurons that showed inhibitory interactions from the other three paws did not differ significantly in response properties from those that showed no interaction effects. These findings are relevant to current criteria for the classification of sensorimotor cortex neurons and lead to remarks on the possible thalamic routes that mediate the interaction effects.