宫内节育器(Cu-IUD)体外释放Cu~(2+)以及含药Cu-IUD体外释放吲哚美辛的研究

目的:比较含Cu及含消炎药IUD释放Cu2+和吲哚美辛(IMC)的释放行为。方法:通过模拟人体宫腔内环境,采用火焰原子吸收光谱仪和UV-752分光光度仪测定TCu380A IUD、MLCu375 IUD和元宫型药Cu365IUD 300d内Cu2+和320d内IMC的释放行为。结果:3种Cu-IUDs的Cu2+都呈现了双相的释放行为:初始阶段的快速释放与随后的稳定缓慢释放。元宫型药Cu365IUD的Cu2+释放为零级过程,其内IMC的体外释放结果符合Weibull方程。结论:3种型号中,元宫型药Cu365IUD中Cu2+的释放最为稳定。依据IMC的体外释放特点,可以解释含药Cu-IUD防治置IUD副作用的功能。     

计算机仿真实验在机能学实验教学中的应用

计算机仿真实验是以虚拟实验动物为实验对象,利用计算机仿真实验软件系统来完成特定实验项目的一种实验教学形式。它是机能学活体动物实验教学的有益补充及延伸。其科学严谨的实验操作流程,丰富的实验项目和处理因素,高实验成功率及文字、语音、图像、动画等多媒体信息并举的实验教学模式,有助于当代大学生综合素质的提高。     

The structure and response properties of Golgi tendon organs in control and hypodynamia-hypokinesia rats

The Golgi tendon organs (GTOs) are encapsulated mechano-receptors that, in normal conditions, monitor via Ib afferent fibers the contractile force. A 14-day period of hypodynamia, absence of weight bearing and hypokinesia, and reduction of motor activity (HH) is known to induce changes in postural muscles such as the soleus. At present, there is no data available regarding the Ib afferent feedback in normal rats (CONT group) and in rats after a hypodynamia-hypokinesia (HH group) period. Consequently, the aim of our study was to determine the HH effects on the morphological (histochemistry on gross morphology) and electrophysiological properties of the GTOs in rat soleus muscle. In the histological study, nine CONT and nineteen HH GTOs of the soleus muscle were identified. The results demonstrated that HH GTOs were morphologically similar to the CONT GTOs. Regarding the electrophysiological study, a L2-L6 laminectomy was performed under deep anesthesia (sodium pentobarbital, 60 mg kg(-1)). Responses in single Ib fibers from the L5 dorsal root to the isometric twitch and tetanic fused contractions of "in-series" motor units (MUs) were recorded. Twenty-three and twenty-eight GTO/MU pairs were studied in the CONT and HH groups, respectively. In the HH group, the Ib afferent response exhibited a decrease in dynamic peak for the high stimulation frequencies and an increase in static sensitivity for all stimulation frequencies. Our results suggest that after an HH period, the GTOs continue to fulfil their mechano-sensory function to signal the contractile force but with a higher static sensitivity.     

Neuromuscular adaptations to spaceflight are specific to postural muscles

The effects of microgravity were determined in muscles of differing function and myofiber-type composition. Rats were assigned either to a 10-day spaceflight mission or to ground-based control conditions. Following the experimental period, hindlimb muscles were obtained from both groups. Cytofluorescent techniques were used to examine neuromuscular junctions (NMJs) from both slow- and fast-twitch fibers. Histochemical procedures were employed to assess myofiber profiles (size and type). Results indicate that microgravity did not alter NMJ structure or myofiber profile in the tibialis anterior, a predominantly fast-twitch, nonpostural muscle. Similarly, the NMJs and myofibers of deep regions of the gastrocnemius, a locomotor muscle possessing a mixed fiber population, were unaffected by spaceflight. In contrast, both myofibers and NMJs of the soleus-a postural muscle-demonstrated significant (P < 0.05) plasticity following exposure to spaceflight. Moreover, NMJs of both fast- and slow-twitch myofibers displayed similar remodeling in that muscle. Our findings suggest that the deleterious effects of microgravity are most apparent among postural muscles, and are manifested both in myofibers and their synapses.     

Functional alterations of mesenteric vascular bed, vas deferens and intestinal tracts in a rat hindlimb unloading model of microgravity

1. Prolonged bed rest or exposure to microgravity may cause several alterations in autonomic nervous system response (ANSR). 2. Hindlimb unloading (HU) rats were used as an animal model of simulated microgravity to investigate ANSR changes. The experiments were carried out to investigate the effects of simulated microgravity on the autonomic nervous response of the perfused mesenteric vascular bed (MVB), vas deferens and the colon and duodenum from 2-week HU rats. 3. In MVB preparations of HU rats, the frequency-dependent increases in perfusion pressure with perivascular nerve stimulation (PNS; 8-40 Hz) were inhibited, whereas the noradrenaline (NA) concentration-dependent (1-100 microM) perfusion pressure increases were potentiated. The latter most probably reflected up-regulation of alpha-adrenergic receptor function. Relaxant responses of NA-precontracted MVB to PNS (4-30 Hz) or isoprenaline were not different between control and HU preparations, while vasodilation induced by the endothelial agonist ACh was reduced. 4. Transmural stimulation (2-40 Hz) induced frequency-dependent twitches of the vas deferens which were reduced in vas deferens of HU rats, while the sensitivity to NA-induced contraction was significantly increased. 5. In the gastroenteric system of HU rat, direct contractile responses to carbachol or tachykinin as well as relaxant or contractile responses to nervous stimulation appeared unchanged both in the proximal colon rings and in duodenal longitudinal strips. 6. In conclusion, HU treatment affects peripheral tissues in which the main contractile mediators are the adrenergic ones such as resistance vessels and vas deferens, probably by reducing the release of neuromediator. This study validates NA signalling impairment as a widespread process in microgravity, which may most dramatically result in the clinical phenotype of orthostatic intolerance.     

Differential effects of alcohol and alcohol expectancy on risk-taking during simulated driving

This study examined the separate and combined effects of alcohol (0.0 or 0.5 g/kg) and alcohol expectancies (none or 2-3 standard drinks) on risk-taking using a simulated-driving lane choice task. In this task, risk-taking was operationalized as choosing a cone-defined lane with a higher relative probability of hitting a cone. When alcohol was received but not expected, the probability of a risky lane choice increased compared with when alcohol was neither expected nor received. However, when subjects both expected and received alcohol, the probability of a risky lane choice was significantly decreased compared with when alcohol was neither expected nor received. These findings suggest that the knowledge of dose received can differentially influence the pharmacological effect of alcohol on decision-making.     

Using simulated patients in a multiprofessional communications skills programme: reflections from the programme facilitators

This paper discusses a multiprofessional, 4-day communication skills programme in which participants explore the challenges of communicating with cancer patients and their families. Effective communication and skilled emotional support are essential prerequisites for high quality care in oncology and palliative care settings. This aspect of care presents major challenges to nurses and other health care professionals. It is acknowledged that health professionals often lack the requisite skills to communicate meaningfully with this patient group and that tangible benefits accrue from training in this area. Using simulated patients, structured feedback and small group discussions, this multiprofessional programme seeks to provide a forum that enables participants to acquire confidence and competence in a safe, comfortable and non-threatening environment. The programme structure presents several challenges in terms of providing a learning experience that addresses the diverse educational of a heterogeneous learning group. Participants' comments and programme facilitators reflections suggest that the programme is successful in addressing these challenges and providing a meaningful learning experience.     

Simulation-based education promoting situation awareness in undergraduate nursing students: A scoping review

AimTo examine simulation-based education (SBE) strategies on situation awareness (SA) in nursing students including the strategies of SBE, the measurement tools of SA during SBE and the effectiveness of SBE on SA.BackgroundSA has been reported as an effective way to identify and manage deteriorating patients. Researchers have suggested that SBE is more effective than other instructional modalities in improving SA. However, SA among nursing students and studies regarding the effectiveness of SBE on SA are limited.DesignThe Arksey and O'Malley scoping review framework was used to guide the review process and the PRISMA-ScR checklist was used to report on this scoping review.MethodsThe databases searched were Medline, CINAHL, EMBASE, EBSCO and Google Scholar from December 2020 to November 2021. Thematic analysis was applied to identify the main findings in the literature.ResultsNine eligible articles were included. Five major themes were identified: SBE situations used to teach SA to nursing students, SBE strategies to improve SA in nursing, effectiveness of SBE on SA in nursing, measurements of SA used during the SBE and experimental studies examining the effectiveness of SBE on SA.ConclusionThis review reveals that SBE may be useful to cultivate SA in nursing students. Future studies that use randomized clinical trials to test the effects of combining different simulation strategies on SA are suggested. Developing more reliable and valid SA global assessment queries and standardizing the query process of SA measurement is also recommended.     

CLINICAL SIMULATED EXPERIMENT ON THE SYNDROMI STANDARDS OF PULMONARY SYSTEM DISEASES

ＣＬＩＮＩＣＡＬＳＩＭＵＬＡＴＥＤＥＸＰＥＲＩＭＥＮＴＯＮＴＨＥＳＹＮＤＲＯＭＩＳＴＡＮＤＡＲＤＳＯＦＰＵＬＭＯＮＡＲＹＳＹＳＴＥＭＤＩＳＥＡＳＥＳＭｕｌｉｎＸｕＱｉｏｕｑｉｎＷａｎｇ（ＨｕｂｅｉＡｃａｄｅｍｙｏｆＴｒａｄｉｔｉｏｎａｌＣｈｉｎｅｓｅ...     

A UPLC–MS/MS method for in vivo and in vitro pharmacokinetic studies of psoralenoside,isopsoralenoside, psoralen and isopsoralen from Psoralea corylifolia extract

Ethnopharmacological relevance

The dried fruit of Psoralea corylifolia L. has been used to prevent and treat vitiligo, osteoporosis, arthralgia and asthma in Traditional Chinese Medicine for some 1600 years. Psoralen (P), isopsoralen (IP), psoralenoside (PO) and isopsoralenoside (IPO) are the major coumarins and coumarin-related benzofuran glycosides in Psoraleae Fructus, which have been reported to show estrogen-like activity, osteoblastic proliferation accelerating activity, antitumor effects and antibacterial activity. The first aim of this study is to develop a rapid, sensitive and selective ultra performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) approach for simultaneous determination of PO, IPO, P and IP in rat plasma and samples collected from in vitro incubation experiments. The second aim is to investigate the pharmacokinetic properties of PO, IPO, P and IP after oral administration of Psoralea corylifolia extract (PCE) to rats. The third aim is to confirm the biotransformation of PO to P or IPO to IP under gastrointestinal conditions.

Materials and methods

A UPLC–MS/MS method with a C18 column and a mobile phase of methanol-0.1% aqueous formic acid was validated according to the criteria in FDA guidelines about bioanalytical method, which was developed to investigate the pharmacokinetic behavior of PO, IPO, P and IP from PCE and the metabolic pathways of PO to P or IPO to IP.

Results

The criteria for establishment of a new UPLC–MS/MS method including selectivity, linearity, accuracy, precision, extraction recovery, matrix effect and stability were validated. This method was successfully applied to the quantitative determination of PO, IPO, P and IP in biological samples collected from both in vitro incubations and in vivo rat experiments. After oral administration of PCE to rat, pharmacokinetic parameters of these four compounds indicated that in vivo biotransformation may occur between PO and P or IPO and IP. Purified benzofuran glycosides fraction (PBGF), containing only PO and IPO, was orally administered to rats to further confirm the biotransformation of PO to P or IPO to IP under gastrointestinal conditions. An in vitro incubation study elucidated that PO and IPO were metabolized to P and IP by intestinal microflora through de-glucosylation.

Conclusions

This paper developed a rapid, sensitive and selective UPLC–MS/MS method for simultaneous determination of PO, IPO, P and IP from PCE in biological samples, and investigated on their comprehensive in vivo and in vitro pharmacokinetic studies. These obtained results showed that the metabolism by intestinal bacteria plays an important role in pharmacological effects of orally administered PCE.