Characteristics of electroacupuncture-induced analgesia in mice: variation with strain,frequency, intensity and opioid involvement

The present study was conducted to evaluate the characteristics of electroacupuncture (EA)-induced analgesia in mice. Three inbred strains of mice (DBA/2, C57BL/6J, BALB/c) and three outbred strains (ICR, LACA, NIH) were used in the experiment. Two pairs of metallic needles were inserted into acupoints ST 36 and SP 6 connected to an electric pulse generator. EA parameters were set as constant current output with alteration of a positive and negative square wave, 0.6 ms in pulse width for 2 Hz and 0.3 ms for 100 Hz. Tail-flick latencies evoked by radiant heat were measured before, during and after EA stimulation. We found that (1) DBA/2 mice showed a significantly more potent analgesic effect than the other five strains in response to both 100 and 2 Hz EA. In this case, the intensities were 1.0-2.0-2.0 mA, 10 min for each intensity totally 30 min. (2) EA analgesia increased as the intensity of stimulation increased from 0.5 to 2.0 mA, but it remained at this plateau when the intensity further increased from 2.0 to 3.0 mA. (3) 10.0 mg x kg(-1) naloxone was needed to block the analgesic effect induced by 2 Hz EA of 2.0 mA, but to block that by 100 Hz, 25.0 mg x kg(-1) was necessary. (4) A positive correlation was observed between analgesia induced by morphine at the dose of 5.0 mg x kg(-1) and by 100 Hz EA in two tested strains DBA/2 and C57BL/6J. In conclusion, EA induces reliable, strain-dependent analgesia in mice. The naloxone-reversibility of EA, a measure of whether it is opioid or non-opioid mediated, is dependent upon intensity and frequency.     

Central neural mechanisms contributing to the perception of tactile roughness

This paper summarizes recent work showing that tactile roughness appreciation increases in a nearly linear fashion as tactile element spacing or spatial period (SP, distance centre-to-centre between raised dots in these experiments) is increased from 1.5 to 8.5 mm. Although a previous study had reported a U-shaped psychophysical function peaking at a nominal SP of 3.2 mm, differences in the surfaces (including changing SP in only one dimension as compared with two and higher dot heights that minimized contact with the smooth floor) likely contributed to the difference in the results. Roughness estimates were also unaffected by a 2-fold change in scanning speed (50 vs. 95 mm/s). Parallel recordings from neurones in primary somatosensory cortex (SI) during a texture discrimination task indicate that the discharge frequency of many SI cells shows a monotonic relation with SP (up to 5 mm tested). For some cells, the texture signals were ambiguous because discharge frequency co-varied with both texture and the scanning speed, as has also been reported for the peripheral mechanoreceptors that are activated by textured surfaces. Yet other SI cells showed a speed-invariant response to surface texture, consistent with perceptual constancy for roughness over a range of scanning speeds. We suggest that such a discharge pattern could be based on a simple intensive, or mean rate, code: an invariant central representation of surface texture could be obtained by subtracting a speed-varying signal from the ambiguous signals that co-vary with roughness and speed.     

Integration Mechanisms and Hospital Efficiency in Integrated Health Care Delivery Systems

This study analyzes integration mechanisms that affect system performances measured by indicators of efficiency in integrated delivery systems (IDSs) in the United States. The research question is, do integration mechanisms improve IDSs' efficiency in hospital care? American Hospital Association's Annual Survey (1998) and Dorenfest's Survey on Information Systems in Integrated Healthcare Delivery Systems (1998) were used to conduct the study, using IDS as the unit of analysis. A covariance structure equation model of the effects of system integration mechanisms on IDS performance was formulated and validated by an empirical examination of IDSs. The study sample includes 973 hospital-based integrated health care delivery systems operating in the United States, carried in the list of Dorenfest's Survey on Information Systems in Integrated Health care Delivery Systems. The measurement indicators of system integration mechanisms are categorized into six related domains: informatic integration, case management, hybrid physician–hospital integration, forward integration, backward integration, and high tech medical services. The multivariate analysis reveals that integration mechanisms in system operation are positively correlated and positively affect IDSs' efficiency. The six domains of integration mechanisms account for 58.9% of the total variance in hospital performance. The service differentiation strategy such as having more high tech medical services have much stronger influences on efficiency than other integration mechanisms do. The beneficial effects of integration mechanisms have been realized in IDS performance. High efficiency in hospital care can be achieved by employing proper integration strategies in operations.     

Drug therapy during labor and delivery, part 2.

PURPOSE: The drug therapy of common conditions and complications during labor and delivery and the fetal and neonatal effects of this therapy are examined. SUMMARY: The pharmacologic therapy of common conditions that occur in labor and delivery primarily involves oxytocin and prostaglandins for cervical ripening and labor induction and systemic and regional narcotic analgesics for pain. Because most medications used in women during labor and delivery do not have Food and Drug Administration-approved labeling, pharmacists should understand the benefits and limitations of medications used in the mother. Although induction and augmentation of labor and the control of pain often require drug therapy, other, less frequent, complications may occur in labor. Drug therapies for these complications include anti-infective agents to treat maternal infection and prevent neonatal diseases; antiretrovirals to reduce perinatal HIV-1 transmission from the mother to the fetus; corticosteroids to prevent fetal lung immaturity; antihypertensives to treat preeclampsia; anticonvulsants to treat eclampsia; antibiotics to prolong pregnancy and improve neonatal outcomes after premature rupture of the membranes; tocolytics for premature labor; and oxytocin, ergot alkaloids, and prostaglandin analogues for postpartum hemorrhage. The fetal and neonatal effects of therapy for the conditions that occur during labor and delivery are usually benign, but significant morbidity and mortality involving the mother, the fetus, and the newborn are ever-present risks. CONCLUSION: Awareness of the conditions and complications requiring drug therapy during labor and delivery will allow hospital pharmacists to make knowledgeable decisions about the rapid accessibility of critical medications in the labor and delivery unit.     

Cloning of two novel P-III class metalloproteinases from Trimeresurus stejnegeri venom gland.

Hemorrhagic toxins are widely distributed in viperid and crotalid snake venoms. Envenomation of Trimeresurus stejnegeri, a member of Crotalidae family, caused potent systemic and local hemorrhage. Up to now, there is no report on hemorrhage toxins from this venom. In this work, we cloned two cDNAs of P-III metalloproteinase precursors, designated as stejnihagin-A and stejnihagin-B, respectively, from T. stejnegeri venom gland. Both cDNAs encode an opening reading frame of 600 amino acid residues, containing a signal sequence, a proprotein domain, a metalloproteinase domain, a disintegrin-like domain and a cystetine-rich domain. Sequence analysis suggested that these two sequences shared highest similarity to the hemorrhagic toxin HR1b from T. flavoviridis. Aligning the deduced mature protein sequences of stejnihagin-A and stejnihagin-B with other snake venom metalloproteinases (SVMPs), we observed that stejnihagin-A and stejnihagin-B, together with HR1b shared the common cysteinyl residue at the position 100 in the metalloproteinase domain. In combination with the phylogenetic analysis, we presumed that stejnihagin-A, stejnihagin-B and HR1b might constitute a novel subclass of P-III SVMPs, named P-IIIc.     

Airborne severe acute respiratory syndrome coronavirus concentrations in a negative-pressure isolation room.

This study used a sensitive polymerase chain reaction method coupled with filter sampling to detect the presence of airborne severe acute respiratory syndrome (SARS) coronavirus in an isolation patient room with a patient with severe acute respiratory syndrome receiving mechanical ventilatory support. Polymerase chain reaction results were negative for SARS coronavirus in room air both before and after patient extubation.     

儿宝颗粒对幼龄厌食大鼠胃黏膜细胞内线粒体、酶原颗粒干预的研究

目的:观察幼龄厌食大鼠胃窦黏膜细胞超微结构的形态变化,探讨儿宝颗粒对其的干预作用。方法:采用电镜观察,CMIAS-98A北航图像分析仪比较厌食大鼠和儿宝颗粒干预后大鼠胃窦黏膜上皮细胞和壁细胞内线粒体及主细胞内酶原颗粒的个数、面积、周长、长径、短径及圆度值的变化。结果:厌食大鼠胃窦黏膜上皮细胞和壁细胞内线粒体及主细胞酶原颗粒的个数、面积、周长、长径、短径及圆度值等与空白组比较发生明显改变,有显著性差异(P<0.05或P<0.01),而儿宝颗粒组胃窦黏膜细胞超微结构与空白组比较无显著差异(P>0.05)。结论:厌食大鼠胃窦黏膜细胞超微结构异常与厌食症的发生有关,而儿宝颗粒能有效干预其结构的异常。     

国人儿童口腔轮替运动速率参考标准的制订

目的口腔轮替运动速率(diadochokinetic rate,DR)是衡量言语产生过程中舌部运动灵活程度以及言语清晰度的一个重要指标。本研究拟制订中国儿童DR参考标准,揭示儿童DR发展的一般规律及特征。方法对900名正常儿童进行DR测量,并做有关数据统计与分析。结果制订了4至18岁中国儿童的DR参考标准。结论①从4岁至7岁,DR的四项指标均呈上升趋势,至7岁达到高峰,虽然在13岁左右又出现高峰,但很快又恢复到7岁水平。因此,7岁可视为DR发展的关键期;②在DR发展中,性别间无显著性差异。