毛花猕猴桃原生质体再生植株根尖染色体数目变异与细胞多核现象

对18株毛花猕猴桃(Actinidia eriantha Benth.)原生质体再生植株的体细胞染色体数做了观察,其中12株为整倍体:二倍体(2n=58)和四倍体(2n=116)各6株;另外6株为混倍体,其染色体数目变化在59～203之间。还发现原生质体再生植株有丝分裂间期细胞存在多核现象,有多核细胞的共10株,细胞核数目以双核和三核较常见,最多的有7个核。对照植株为2n=2x=58,未发现多核细胞。     

褶纹冠蚌外套膜组织培养的分泌物的偏光显微镜观察

以淡水育珠贝中珍珠形成较快的褶纹冠蚌为材料,用相差显微镜观察组织培养的外套膜的分泌物的形成和变化,用偏光显微镜观察分泌物的双折射现象,并与活体外套膜的分泌物、贝壳的角质层、棱柱层、珍珠层的双折射现象进行比较。结果表明;离体培养的外套膜细胞不仅能产生活体细胞相同的分泌物,而且分泌物还能在培养过程中形成结晶,并逐渐生长。发现外套膜的不同部位分区培养所形成的分泌物的性状与结晶性质和活体有一致性,表明组织培养的外套膜小片具有贝体原来的组织结构、分化特征和分泌功能。     

Recombinant protein production in insect larvae: host choice,tissue distribution,and heterologous gene instability

The expression of the fluorescent protein, DsRed, facilitates the optimization of protein production in orally-infected whole larvae. Trichoplusia ni was shown to be a much better host for recombinant AcMNPV compared to four other noctuid Lepidopteran species achieving 100% infectivity at the minimal tested dose. The highest density of marker protein was found in endothelial and tracheal cells, fat body, and hemocytes. Trichoplusia ni larvae possessed visually detected color over sequential passages of oral infection until the sixth round. Western blot analysis confirmed the progressive decrease of both tetramer and monomer forms of DsRed. The intact DsRed gene and promoter region was present in late passages, but viral population carrying the heterologous gene had dropped more than 2-logs after the fifth round while the amount of total viral DNA remained unchanged over sequential passages. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A recovery-relapse epidemic model with spatial diffusion

An epidemic model of an infectious phenomenon is analyzed. The model allows for an age-dependency to describe the phases of incubation, recovery, and relapse, and for a spatial dependency to describe diffusion of the population in geographical space.Supported in part by the National Science Foundation Grant NSF MCS 7903047     

Cervical flexion–relaxation response to neck muscle fatigue in males and females

In this study the effect of muscle fatigue on the cervical spine flexion–relaxation response was studied. Twenty healthy participants (10 males and 10 females) were recruited for data collection. The Sorenson protocol was utilized to induce neck muscle fatigue. Surface electromyography and optical motion capture systems were used to measure neck muscle activation and head–neck posture, respectively. A post-fatigue reduction in the Flexion–Relaxation Ratio (FRR) and higher FRR for females compared to males were observed. A post-fatigue decrease was also observed in the onset and offset angles resulting in an expansion of the myoelectric silence period. Gender had no effect on the onset and offset angles of the silence period. Post-fatigue shift in the onset and offset angles and the expansion of the silence period indicate an increased contribution by the passive viscoelastic tissues in stabilizing the cervical spine under fatigued condition.     

Thermal Biofeedback for Primary Raynaud’s Phenomenon: A Review of the Literature

The clinical presentation of primary Raynaud’s phenomenon (RP) derives from various pathogenic triggers. The use of thermal biofeedback (TBF) may be of benefit in reducing the severity and frequency of attacks. This article summarizes the relevant research regarding the pathophysiology of primary RP and mechanism of TBF for RP. Systematic reviews of the efficacy of TBF for RP and treatment guidelines for clinicians are provided. The panel concludes that the level of evidence for TBF efficacy is categorized as Level IV: efficacious. The rationale, based on three randomized controlled trials conducted in independent laboratories, demonstrated “superiority or equivalence” of treatments that include TBF. However, randomly controlled trials (RCT) with positive clinical outcomes tended to be small. A large RCT with negative results did not effectively teach handwarming skills. Procedures for reviewing and rating of the levels of evidence of efficacy of studies was based on the Template for Developing Guidelines for the Evaluation of the Clinical Efficacy of Psychophysiological Interventions developed by the joint task force of the AAPB and the Society for Neuronal Regulation (SNR).     

对483 例住院病人退院现象的调查分析

目的：分析住院病人退院现象的增多,找出医院管理环节中诸多不合理的因素,合理调配医院现有资源,加强医院整体管理水平,减少不正常退院现象的发生。     

The relation between the flexion relaxation phenomenon onset angle and lumbar spine muscle reflex onset time in response to 30 min of slumped sitting

Viscoelastic creep of spine tissue, induced by submaximal spine flexion in sitting, can delay the onset of the flexion-relaxation phenomenon (FRP) and low back reflexes (LBR). Theoretically, these two outcome measures should be correlated; however, no studies have investigated this. This study aims to determine whether 30 min of near-maximal spine flexion will affect the onset of FRP and LBR in the lumbar erector spinae (LS) and lumbar multifidus (LM), and to examine the relation between these parameters. 15 participants were recruited (9F, 6M). Spine angle (between L1 and S2) was monitored synchronously with bilateral muscle activity in the LS (L1) and the LM (L4). FRP onset and LBR were measured in a randomized order before and after 30 min of slouched sitting. No significant difference was found for any muscle LBR onset time between pre and post-sitting (p > 0.05). A significant increase in FRP onset was found in the RLM (p = 0.016) following sitting. No significant correlation was found between the FRP and the LBR for any muscle. These results suggest that the LBR onset might not be as sensitive as an outcome measure to investigate shorter exposures of sitting as FRP.     

Fungal Inoculation and Elevated CO2 Mediate Growth of Lolium Mutiforum and Phytolacca Americana,Metal Uptake,and Metal Bioavailability in Metal-Contaminated Soil: Evidence from DGT Measurement

Fungal inoculation and elevated CO₂ may mediate plant growth and uptake of heavy metals, but little evidence from Diffusive Gradients in Thin-films (DGT) measurement has been obtained to characterize the process. Lolium mutiforum and Phytolacca americana were grown at ambient and elevated CO₂ on naturally Cd and Pb contaminated soils inoculated with and without Trichoderma asperellum strain C3 or Penicillium chrysogenum strain D4, to investigate plant growth, metal uptake, and metal bioavailability responses. Fungal inoculation increased plant biomass and shoot/root Cd and Pb concentrations. Elevated CO₂ significantly increased plants biomass, but decreased Cd and Pb concentrations in shoot/root to various extents, leading to a metal dilution phenomenon. Total Cd and Pb uptake by plants, and DGT-measured Cd and Pb concentrations in rhizosphere soils, were higher in all fungal inoculation and elevated CO₂ treatments than control treatments, with the combined treatments having more influence than either treatment alone. Metal dilution phenomenon occurred because the increase in DGT-measured bioavailable metal pools in plant rhizosphere due to elevated CO₂ was unable to match the increase in requirement for plant uptake of metals due to plant biomass increase.     

Evasion from accelerated blood clearance of nanocarrier named as “Lactosome” induced by excessive administration of Lactosome

Background

Nanoparticle of Lactosome, which is composed of poly(l-lactic acid)-base depsipeptide with diameter of 35 nm, accumulates in solid tumors by the enhanced permeability and retention (EPR) effect. However, a pharmacokinetic alteration of Lactosome was observed when Lactosome was repeatedly administered. This phenomenon is named as the Lactosome accelerated blood clearance (ABC) phenomenon. In this study, the effect of Lactosome dose on the ABC phenomenon was examined and discussed in terms of immune tolerance.

Methods

To tumor transplanted mice, Lactosome (0–350 mg/kg) was administrated. At 7 days after the first administration, indocyanine green (ICG)-labeled Lactosome (ICG-Lactosome, 0–350 mg/kg) was injected. Near-infrared fluorescence imaging was performed, and biodistribution of ICG-Lactosome was evaluated. Further, the produced amounts of anti-Lactosome IgM were determined by enzyme-linked immunosorbent assay (ELISA).

Results

ICG-Lactosome accumulated in the tumor region when the first Lactosome dose exceeded over 150 mg/kg. The amounts of anti-Lactosome IgM were inversely correlated with the first Lactosome doses. Even after establishment of the Lactosome ABC phenomenon with the first Lactosome dose as low as 5.0 mg/kg, the Lactosome ABC phenomenon can be evaded apparently by dosing ICG-Lactosome over 50 mg/kg regardless of anti-Lactosome IgM production.

Conclusions

There are two different mechanisms for evasion from the Lactosome ABC phenomenon before and after its establishment. In either mechanism, however, the Lactosome ABC phenomenon can be evaded by excessive administration of Lactosome.

General significance

Lactosome is a potential nanocarrier for drug and/or imaging agent delivery, which can be used for frequent administrations without significant pharmacokinetic alterations.