Evaluation of an independent prestin mouse model derived from the 129S1 strain

Studies using the prestin knockout mouse indicate that removal of the outer hair cell (OHC) motor protein is associated with loss of sensitivity, frequency selectivity and somatic electromotility. Here we provide data obtained from another prestin mouse model that was produced commercially. In vivo electrical recordings from the round window indicate that the phenotype is similar to that of the original knockout generated by the Zuo group at St. Jude Children's Research Hospital. Hence, compound action potential (CAP) thresholds are shifted in a frequency-dependent manner and CAP tuning curves at 12 kHz are flat for masker frequencies between 3 and 18 kHz. Although CAP input-output functions at 6 kHz show a shift in sensitivity at low levels, responses approach wild-type magnitudes at high levels where the cochlear amplifier has less influence. In order to confirm that the loss of sensitivity and frequency selectivity is due to loss of prestin, we performed immunohistochemistry using a prestin antibody. Cochlear segments from homozygous mutant mice showed no fluorescence, while wild-type mice displayed a fluorescent signal targeted to the OHC's lateral membrane. Absence of prestin protein was confirmed using LDS-PAGE/Western blot analysis. These results indicate that the loss of function phenotype is associated with loss of prestin protein. Lack of prestin protein also results in a shortening of OHC length to approximately 60% of wild-type, similar to that reported previously by Liberman's group. The linkage shown between the loss of prestin protein and abnormal cochlear function validates the original knockout and attests to the importance of OHC motor function in the auditory periphery.

Effects of Ionic Liquid as Additive and the pH of the Mobile Phase on the Retention Factors of Amino Benzoic Acids in RP-HPLC

As an organic salt, ionic liquids are widely used as new solvent media. In this paper, three positional isomers, such as o-amino benzoic acid, m-amino benzoic acid, and p-amino benzoic acid are separated with four different ionic liquids as additives to the mobile phase using reversed-phase (RP) high-performance liquid chromatography (HPLC). Amino benzoic acids are biologically active substances; the p-isomer is present in a group of water-soluble vitamins and is widely known as a sunscreen agent. The ionic liquids used are 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium methylsulfate, and 1-octyl-3-methylimidazolium methylsulfate. The effects of the length of the alkyl group on the imidazolium ring and its counterion, the concentrations of the ionic liquid, and the effect of the pH of the mobile phase on the retention factor of the amino benzoic acid isomers are studied. Separation with the ionic liquid in the eluent was better than the separation without the ionic liquid. The pH mainly affected the retention and elution order of the solutes in RP-HPLC.

Development of temporal response properties and contrast sensitivity of V1 and V2 neurons in macaque monkeys

The temporal contrast sensitivity of human infants is reduced compared to that of adults. It is not known which neural structures of our visual brain sets limits on the early maturation of temporal vision. In this study we investigated how individual neurons in the primary visual cortex (V1) and visual area 2 (V2) of infant monkeys respond to temporal modulation of spatially optimized grating stimuli and a range of stimulus contrasts. As early as 2 wk of age, V1 and V2 neurons exhibited band-pass temporal frequency tuning. However, the optimal temporal frequency and temporal resolution of V1 neurons were much lower in 2- and 4-wk-old infants than in 8-wk-old infants or adults. V2 neurons of 8-wk-old monkeys had significantly lower optimal temporal frequencies and resolutions than those of adults. Onset latency was longer in V1 at 2 and 4 wk of age and was slower in V2 even at 8 wk of age than in adults. Contrast threshold of V1 and V2 neurons was substantially higher in 2- and 4-wk-old infants but became adultlike by 8 wk of age. For the first 4 wk of life, responses to high-contrast stimuli saturated more readily in V2. The present results suggest that although the early development of temporal vision and contrast sensitivity may largely depend on the functional maturation of precortical structures, it is also likely to be limited by immaturities that are unique to V1 and V2.

Molecular Characterization of a Xiphinema hunaniense Population with Morphometric Data of all Four Juvenile Stages

A population of Xiphinema hunanienseWang and Wu, 1992 with all four juvenile stages was found in the rhizosphere of Pinus sp. in Hangzhou, Zhejiang, China. Morphometrics of 18 females and 35 juveniles of this population are given herein. Detailed morphology and morphometrics of the four juvenile stages are provided. Further comparisons based on morphometrics of the population with previous studies of the females and the first-stage juveniles of X. hunaniense with X. radicicola are given, and morphological variation in X. hunaniense populations are discussed. A revised polytomous key code of Loof and Luc (1990) for X. hunaniense identification is provided, i.e., A1- B4- C4- D4/5- E1- F2(3)- G2- H2-I3- J4- K2- L1. In addition, the sequence of the D2 and D3 expansion region of the 28S rRNA gene was analyzed and compared with sequences of closely related species downloaded from the NCBI database. Cluster analysis of sequences confirmed and supported the species identifications.

Effects of perceptual learning on local stereopsis and neuronal responses of V1 and V2 in prism-reared monkeys

Visual performance improves with practice (perceptual learning). In this study, we sought to determine whether or not adult monkeys reared with early abnormal visual experience improve their stereoacuity by extensive psychophysical training and testing, and if so, whether alterations of neuronal responses in the primary visual cortex (V1) and/or visual area 2 (V2) are involved in such improvement. Strabismus was optically simulated in five macaque monkeys using a prism-rearing procedure between 4 and 14 wk of age. Around 2 yr of age, three of the prism-reared monkeys ("trained" monkeys) were tested for their spatial contrast sensitivity and stereoacuity. Two other prism-reared monkeys received no training or testing ("untrained" monkeys). Microelectrode experiments were conducted around 4 yr of age. All three prism-reared trained monkeys showed improvement in stereoacuity by a factor of 7 or better. However, final stereothresholds were still approximately 10-20 times worse than those in normal monkeys. In V1, disparity sensitivity was drastically reduced in both the trained and untrained prism-reared monkeys and behavioral training had no obvious effect. In V2, the disparity sensitivity in the trained monkeys was better by a factor of approximately 2.0 compared with that in the untrained monkeys. These data suggest that the observed improvement in stereoacuity of the trained prism-reared monkeys may have resulted from better retention of disparity sensitivity in V2 and/or from "learning" by upstream neurons to more efficiently attend to residual local disparity information in V1 and V2.

Puerarin injection for unstable angina pectoris

BACKGROUND

Puerarin is extracted from the Chinese herb puerariae lobata. Many users of Chinese herbal medicine believe that puerarin has positive effects in the treatment of coronary heart disease (CHD). In recent years puerarin injection has been widely used to treat CHD and angina pectoris.

OBJECTIVES

To assess the benefits and harms of puerarin injection for unstable angina.

SEARCH STRATEGY

The following electronic databases were searched: The Cochrane Controlled Trials Register on The Cochrane Library (Issue 3, 2004), MEDLINE (1995 to 2004), EMBASE (1995 to 2004), CBM (1995 to 2004), Chinese Cochrane Centre Controlled Trials Register (to 2004), Current Controlled Trials (www.controlled-trials.com) and The National Research Register. We also hand searched 60 Chinese traditional medicine journals.

SELECTION CRITERIA

Randomised controlled trials undertaken on adults with unstable angina evaluating the following types of interventions: Puerarin injection compared to western drugs or placebo, or puerarin injection used with western drugs compared to western drugs alone.

DATA COLLECTION AND ANALYSIS

Data were extracted and analysed independently by two reviewers. Differences in data extraction and analysis were resolved by consensus, referring back to the original article. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

20 trials involving 1240 people were included. All trials identified were classified as having a high risk of bias because of poor reported methodology. The duration of treatment was 7-20 days and no information supplied suggested longer follow-ups were conducted for any trials. This limited the observation to participants who were not undertaking normal activities of daily living. The primary outcome (death) was not report in any trial. For all the secondary outcome measures, frequency of acute angina attacks, improvements in ECG, doses and incidence of nitroglycerine needed and levels of plasma endothelin, there was no evidence that puerarin had better or worse effects to other conventional treatments. There was strong evidence to suggest that puerarin injection plus western drugs was a better treatment option than western drugs alone.

AUTHORS' CONCLUSIONS

Puerarin injection may be effective in unstable angina when used in addition to conventional treatments. However, these finding should be interpreted with care because of the very low methodological quality of studies and potential publication bias. In the light of the findings, a more rigorously designed, randomised double-blind placebo-controlled trial is needed.

Stable Isotope Records from Mount Logan, Eclipse Ice Cores and Nearby Jellybean Lake. Water Cycle of the North Pacific Over 2000 Years and Over Five Vertical Kilometres: Sudden Shifts and Tropical Connections

Three ice cores recovered on or near Mount Logan, together with a nearby lake record (Jellybean Lake), cover variously 500 to 30 000 years. This suite of records offers a unique view of the lapse rate in stable isotopes from the lower to upper troposphere. The region is climatologically important, being beside the Cordilleran pinning-point of the Rossby Wave system and the Aleutian Low. Comparison of stable isotope series over the last 2000 years and model simulations suggest sudden and persistent shifts between modern (mixed) and zonal flow regimes of water vapour transport to the Pacific Northwest. The last such shift was in A.D. 1840. Model simulations for modern and “pure” zonal flow suggest that these shifts are consistent regime changes between these flow types, with predominantly zonal flow prior to ca. A.D. 1840 and modern thereafter. The 5.4 and 0.8 km asl records show a shift at A.D. 1840 and another at A.D. 800. It is speculated that the A.D. 1840 regime shift coincided with the end of the Little Ice Age and the A.D. 800 shift with the beginning of the European Medieval Warm Period. The shifts are very abrupt, taking only a few years at most.

Julibroside J8-induced HeLa cell apoptosis through caspase pathway

The julibroside J8 was isolated from the Albizia julibrissin and evaluated for antiproliferatived on six cancer cell lines (BGC-823, Bel-7402, HeLa, PC-3MIE8, MDA-MB-435 and LH-60) in vitro. Julibroside J8 at 100 microg mL- 1 (46.08 micromol.L- 1) significantly inhibited growth in the first three cell lines. In addition, in HeLa cells typical apoptotic changes in morphology were observed, and further, nuclear damage was observed by Giemsa staining and DNA fragmentation was exhibited. Effects of julibrosideJ8 on induction of DNA fragmentation, caspase-3 activation and downregulation of ICAD expression were effectively inhibited by a caspase-3 inhibitor, z-DEVD-fmk. In addition, apoptosis induced with julibroside J8 was associated with an increase in expression of the apoptosis inducer Bax, and a significant reduction in expression of the apoptosis suppressor Bcl-2 in mitochondria. These results suggest that julibroside J8 induces HeLa death through caspase pathway.

HIV-1 infection and AIDS: consequences for the central nervous system

Infection with the human immunodeficiency virus-1 (HIV-1) can induce severe and debilitating neurological problems that include behavioral abnormalities, motor dysfunction and frank dementia. After infiltrating peripheral immune competent cells, in particular macrophages, HIV-1 provokes a neuropathological response involving all cell types in the brain. HIV-1 also incites activation of chemokine receptors, inflammatory mediators, extracellular matrix-degrading enzymes and glutamate receptor-mediated excitotoxicity, all of which can trigger numerous downstream signaling pathways and disrupt neuronal and glial function. This review will discuss recently uncovered pathologic neuroimmune and degenerative mechanisms contributing to neuronal damage induced by HIV-1 and potential approaches for development of future therapeutic intervention.

Cortical Effects of Brief Daily Periods of Unrestricted Vision During Early Monocular Form Deprivation

Experiencing daily brief periods of unrestricted vision during early monocular form deprivation prevents or reduces the degree of resulting amblyopia. To gain insight into the neural basis for these “protective” effects, we analyzed the monocular and binocular response properties of individual neurons in the primary visual cortex (V1) of macaque monkeys that received intermittent unrestricted vision. Microelectrode-recording experiments revealed significant decreases in the proportion of units that were dominated by the treated eyes, and the magnitude of this ocular dominance imbalance was correlated with the degree of amblyopia. The sensitivity of V1 neurons to interocular spatial phase disparity was significantly reduced in all treated monkeys compared with normal adults. With unrestricted vision, however, there was a small but significant increase in overall disparity sensitivity. Binocular suppression was prevalent in monkeys with constant form deprivation but significantly reduced by the daily periods of unrestricted vision. If neurons exhibited consistent responses to stimulation of the treated eye, monocular response properties obtained by stimulation of the two eyes were similar. These results suggest that the observed protective effects of brief periods of unrestricted vision are closely associated with the ability of V1 neurons to maintain their functional connections from the deprived eye and that interocular suppression in V1 may play an important role in regulating synaptic plasticity of these monkeys.

Feasibility of Supercritical Fluid Chromatography/Mass Spectrometry of Polypeptides with Up to 40-Mers

Supercritical fluid chromatography (SFC) provides a number of advantages over traditional HPLC such as speed, practical use of longer columns, a normal-phase retention mechanism, and reduced use of organic solvents. Yet, it has been a technique traditionally limited to relatively nonpolar compounds. The nature of SFC mobile and stationary phases did not allow the elution of ionic compounds or of peptides, except, in the latter case, for the most hydrophobic peptides. The characterization of peptides is critically important for drug discovery and development in the pharmaceutical industry, as well as for a variety of other important applications. Here, for the first time to our knowledge, we show that relatively large peptides (at least 40 mers), containing a variety of acidic and basic residues, can be eluted in SFC. We used trifluoroacetic acid as additive in a CO2/methanol mobile phase to suppress deprotonation of peptide carboxylic acid groups and to protonate peptide amino groups. A 2-ethylpyridine bonded silica column, which was specifically developed for SFC, was used for the majority of this work. The relatively simple mobile phase was compatible with mass spectrometric detection.