Roles of inter- and intramolecular vibrations and band-hopping crossover in the charge transport in naphthalene crystal

We calculate the hole and electron mobilities in naphthalene crystal from 10 to 300 K within the framework of the Holstein-Peierls model coupled with first-principles density-functional-theory-projected tight-binding band structures. All the electron-phonon coupling constants, including both local and nonlocal parts for inter- and intramolecular vibrations, have been taken into considerations through density functional theory. The band-hopping crossover transition temperature for the electron transport in the c' axis is calculated to be around 23 K. We have identified a few high frequency intramolecular vibrations which are very important to the charge transport in naphthalene crystal due to their comparatively large electron-phonon coupling constants. However, their contributions to the temperature dependence of mobility are minor because of the small phonon occupations and small nonlocal coupling strengths. The low frequency intermolecular modes (longitudinal optical modes) are found to be the major contributions to the temperature dependent charge transfer properties in naphthalene crystal. Even though the calculated qualitative temperature dependence is in agreement with experiment, the predicted absolute mobility is about one to two orders of magnitude larger.

Formation of subwavelength periodic structures on tungsten induced by ultrashort laser pulses

The evolution of surface morphology of tungsten irradiated by single-beam femtosecond laser pulses is investigated. Ripplelike periodic structures have been observed. The period of these ripples does not show a simple relation to the wavelength and angle of incidence. The orientation of ripples is aligned perpendicularly to the direction of polarization for linearly polarized light. Surprisingly, we find that the alignment of the ripple structure turned left or right by 45 degrees with respect to the incident plane when using right and left circularly polarized light, respectively. The period of the ripple can be controlled by the pulse energy, the number of pulses, and the incident angle. We find a clear threshold for the formation as a function of pulse energy and number of pulses. The mechanism for the ripple formation is discussed, as well as potential applications in large-area structuring of metals.

Increased cross-correlation in cascaded four-wave mixing processes

We report the measurement of increased noise cross-correlation between stokes and anti-stokes beams created in cascaded four-wave mixing processes with dual pump wavelengths. This method may be useful in creating highly correlated twin beams for various applications including quantum information processing.

Modular microdrop generator

We present the design of a simple, modular, and inexpensive generator for droplets with diameters of 20-150 microm. The instrument is based on piezoelectric pressure injection. Its main components, their functionality, and instructions for reliable operation are described in detail. The option of charging microdrops is also discussed.

Platelet phospholipid n-3 PUFA negatively associated with plasma homocysteine in middle-aged and geriatric hyperlipaemia patients

Studies showed that increased dietary intake of n-3 polyunsaturated fatty acids (PUFA) has a cardiovascular beneficial effect. Increased plasma phospholipid (PL) docosahexaenoic acid (22:6n-3) is associated with decreased plasma homocysteine (Hcy). The aim of this study was to investigate the relationship between platelet PL fatty acid and plasma Hcy in middle-aged and geriatric hyperlipaemia patients (50 males, 31 females) and 65 healthy subjects (43 males, 22 females) in Hangzhou, China. Plasma Hcy demonstrated significant positive correlation with adrenic acid (22:4n-6) (r = 0.188, P = 0.018) and negative correlation with 22:6n-3 (r = -0.277, P = 0.001) and the ratio of n-3/n-6 (r = -0.231, P = 0.003) in sex-, age- and BMI-controlled partial correlation analysis. The present results suggest that increased ratio of n-3/n-6 PUFA in platelet PL is associated with decreased thrombotic risks such as plasma Hcy in middle-aged and geriatric hyperlipaemia patients in Hangzhou.

Marrow mesenchymal stem cells transduced with TPO/FL genes as support for ex vivo expansion of hematopoietic stem/progenitor cells

A new marrow-derived mesenchymal stem cell (hMSC) line that could support expansion of hematopoietic stem/progenitor cells (HSPCs) was developed. Primary hMSCs were infected with retrovirus containing Flt-3 ligand and thrombopoietin genes. CD34+ cells from cord blood were expanded with primary hMSCs or transduced hMSCs. The expansion of total nucleated cells, CD34+ cells and mixed colonies containing erythroid and myeloid cells and megakaryocytes for 2 weeks coculture with transduced hMSCs was remarkably increased. The outputs of long-term culture-initiating cells for 2 and 4 weeks coculture with transduced hMSCs were also largely increased. The expansion rates of HSPCs with transduced hMSCs were unchanged for 6 weeks. In contrast, the expansion rates of HSPCs with primary hMSCs declined drastically through 6 weeks. SCID-repopulating cell expansion with transduced hMSCs for 4 weeks was significantly higher than that of uncultured CD34,+ cells and HSPCs expanded with primary hMSCs.

Precision measurement of the refractive index of air with frequency combs

We report an experimental method for high-precision refractive index measurement using a Michelson interferometer setup with a femtosecond optical frequency comb as the light source. We demonstrate this technique by measuring the refractive index of air, under different pressures, inside a 29 m multipass cell. Both spectral and temporal interferograms are recorded. The method has a sensitivity of 6.2 x 10(-9) and a standard error of 7.4 x 10(-8) at fixed parameters (pressure and temperature). The possible variation of the density factor from the Lorentz-Lorenz equation is also discussed.

Efficient generation of correlated photon pairs in a microstructure fiber

We report efficient generation of correlated photon pairs through degenerate four-wave mixing in a microstructure fiber. With 735.7 nm pump pulses producing correlated signal (688.5 nm) and idler (789.8 nm) photons in a 1.8 m microstructure fiber, we detect photon pairs at a rate of 37.6 kHz with a coincidence/ accidental contrast of 10:1 with deltalambda = 0.7 nm. This is the highest rate to our knowledge reported to date in a fiber-based photon source. The light source is highly nonclassical as defined by the Zou-Wang-Mandel inequality, which is violated by 1100 times the uncertainty.

Generation of correlated photon pairs in a microstructure fiber

We propose and experimentally demonstrate a new method of generating correlated photons in a microstructure fiber by means of a reversed degenerate four-wave-mixing process. Here one photon is annihilated from each of the bichromatic pump pulses to generate a pair of photons at the mean frequency. For a microstructure fiber as short as 1.5 m the measured coincidence counting rate is approximately eight times that of the accidental coincidences with a peak pump power of 0.25 W.

Intractable bladder tamponade due to left internal pudendal and obturator arterial bleeding induced by erection: a superselective arteriography followed by transcatheter arterial embolization

Bladder tamponade is an uncommon clinical symptom among men suffering during sexual intercourse. The authors report on a 46-year-old man for whom this symptom appeared 4-5 years prior to hospitalization. Angiography confirmed the presence of left pudendal and obturator arterial bleeding, and embolotherapy of the internal pudendal and obturator arteries was performed. There was no mortality, or limb loss or sexual potency loss at follow-up.

Amplified total internal reflection

Totally internal reflected beams can be amplified if the lowerindex medium has gain. We analyze the reflection and refraction of light, and analytically derive the expression for the Goos-Hänchen shifts of a Gaussian beam incident on a lower-index medium, both active and absorptive. We examine the energy flow and the Goos-Hänchen shifts for various cases. The analytical results are consistent with the numerical results. For the TE mode, the Goos-Hänchen shift for the transmitted beam is exactly half of that of the reflected beam, resulting in a "1/2" rule.

LC method for the determination of oxcarbazepine in pharmaceutical preparations

A simple and accurate HPLC method for determination of oxcarbazepine (OXC) in a new tablet formulation is described. Chromatographic separation was achieved on a Diamonsil C18 column using a mobile phase consisting of acetonitrile, potassium phosphate monobasic buffer (pH 6.8) and water (36:8:56, v/v) at a flow rate of 1.0 ml/min. Absorbance was monitored at 255 nm where OXC has maximum absorption. The linear range of detection for OXC was from 9.96 to 99.6 microg/ml. The proposed method was validated for selectivity, precision, accuracy and limits of detection and quantitation, etc.

Spinal MR findings in spontaneous intracranial hypotension

Whole spine magnetic resonance (MR) imaging was used to evaluate the shape, size, signal intensity, and enhancement of the spinal spaces in a series of six patients with spontaneous intracranial hypotension (SIH). In all patients varying degrees of shrunken dural sacs, expanded extradural spaces with delayed homogeneous enhancement, and distended epidural venous plexuses were noted. In 83% (5/6) of patients, the MR signal of the expanded extradural space was similar to that of cerebrospinal fluid; 17% (1/6) showed an excessive fat deposit in the epidural space. Sixty-seven percent (4/6) of patients had a visible peridural membrane. After relief of the symptoms, one patient (1/4) showed persistence of the spinal abnormalities even though the brain abnormalities disappeared. In conclusion, the spinal MR findings of SIH, like its brain counterpart, are characteristic. In cases with clinical suspicion but without support from brain MR imaging, spinal MR imaging may be helpful in establishing the diagnosis.

Cervical carcinoma: MR imaging with integrated endorectal/phased-array coils: a pilot study

The purpose of this study was to investigate the value of using MRI with integrated endorectal/phased-array coils for the staging and determination of the extent of cervical carcinoma. Twenty-two consecutive patients with biopsy-proven cervical carcinoma underwent MRI with integrated endorectal/phased-array coils before treatment. Magnetic resonance imaging was compared with clinical staging using surgical and pathological results as the gold standard. Eighteen of 22 patients underwent surgery. Seventeen of the 18 patients were correctly staged using an integrated endorectal/phased-array MRI with an overall staging accuracy of 94%. Fourteen of the 18 patients had a correct clinical staging with an overall staging accuracy of 78%. The overall accuracy of pelvic lymph node metastasis detection was 89% on MRI. These data showed that MRI using integrated endorectal/phased-array coils was more accurate than the clinical approach for the staging of cervical carcinoma. Magnetic resonance imaging using integrated endorectal/phased-array coils is a highly promising modality for detecting and staging cervical carcinomas.

Evaluation of mixed hematopoietic chimerism in pediatric patients with leukemia after allogeneic stem cell transplantation by quantitative PCR analysis of variable number of tandem repeat and testis determination gene

In order to monitor the clinical outcome of pediatric patients with leukemia following allogeneic hematopoietic transplantation, tests of variable number of tandem repeat (VNTR) and sex determination by quantitative polymerase chain reaction (PCR) were performed. PCR results combined with the blast counts from 21 leukemia patients were analyzed. Complete chimerism (100% donor cells) was found in 15 cases with remission, and incomplete chimerism in six cases with relapse. In the majority of cases, complete chimerism was always associated with no detectable blasts, while blasts were often detected in association with incomplete chimerism. There is significant correlation (P<0.0001) between the percentage of donor DNA and blast percentage in these patients. Early detection of incomplete chimerism may therefore predict a poor prognosis. In one patient (case 15), a differing percentage of donor DNA was observed between samples of bone marrow and peripheral blood collected on the same day. This may be due to the fact that allogeneic stem cells proliferate at different rates depending on their environment (bone marrow or peripheral blood). In addition, 100% donor cells found in the peripheral blood may not reflect the number of cells in the bone marrow. In case 17, asynchronous engraftment of donor cells was present between the white and red blood cell lineages, indicating that the degree of chimerism may not be the same in all cell lineages. At the time of this report, the significance of this observation is unknown and needs further investigation.

[Geometrical dummy used for ergonomic evaluation on early stage cockpit conceptual design]

Objective. Basing on the need of cockpit ergonomic design, to set up a geometrical dummy. Method. Surface partition of the dummy, source of the curved face data, express of the curved face, degree of freedom of the human joint, coordinate system of the parts, position of the human segment centroid and weight of the human segment were cleared up first, then geometrical dummy was displayed with three-dimensional software. Result. The geometrical dummy could simulate some basic body movements and postures for ergonomic analysis. Conclusion. The geometrical dummy was suitable for present study and engineering design.

Auxin distribution and transport during embryogenesis and seed germination of Arabidopsis

Auxin distribution during embryogenesis and seed germination were studied with transgenic Arabidopsis plants expressing GUS gene driven by a synthetic DR5 promoter, an auxin responsive promoter. The results showed that GUS activity is higher in ends of hypophysis and cotyledon primordia of heart-, torpedo- and cotyledon-stage embryos, leaf tip area, lateral root primordia, root apex and cotyledon of young seedlings. And GUS accumulated in root apex of the seedlings grown on auxin transport inhibitor containing media. All these suggested that above-mentioned part of the organs and tissues have a higher level of auxin, and auxin polar transport inhibitor could cause the accumulation of auxin in root apex. And auxin transport inhibitor also resulted in aberration of Arabidopsis leaf pattern formation, root gravitropism and elongation.

Intramedullary high signal intensity on T2-weighted MR images in cervical spondylotic myelopathy: prediction of prognosis with type of intensity

PURPOSE

To examine whether the different appearances of intramedullary high signal intensity (SI) on T2-weighted MR images in cervical spondylotic myelopathy are related to differences in surgical prognosis.

MATERIALS AND METHODS

The magnetic resonance (MR) findings and Japanese Orthopedic Association (JOA) score of 64 cervical spondylotic myelopathy patients, who underwent decompression surgery, were evaluated. SIs were classified as type 0 if no intramedullary high SI on T2-weighted MR images was noted, type 1 if a predominantly (>50%) faint and fuzzy border of high SI was noted, or type 2 if a predominantly (>50%) intense and well-defined border of high SI was noted. Postoperative JOA scoring and MR imaging were also performed 6 months after surgery. Recovery ratios were calculated.

RESULTS

There were 20 type 0, 23 type 1, and 21 type 2 cases. Statistical analyses showed no significant difference in age, sex, cervical curvature, and preoperative JOA score between the three groups. Statistical analyses of the recovery ratio showed significantly poor prognosis of type 2 compared with type 1 (P < .001) and type 0 (P =.001), but no difference between types 0 and 1 (P = .317). After controlling for factors of age, sex, preoperative JOA score, cervical curvature, and cord compression ratio, analysis of covariance showed the same result.

CONCLUSION

Type 1 intramedullary high SI on T2-weighted MR images indicates a better surgical outcome than does type 2.

Bis(N-octylsalicylideniminato-N,O)copper(II)

In the title compound, [Cu(C(15)H(22)NO)(2)], the Cu(II) cation lies on a centre of symmetry. The coordination geometry about the Cu(II) ion is a parallelogram, formed by the N(2)O(2) donor set of the two bidentate long alkane chain Schiff base imine-phenol ligands. The Cu-N and Cu-O distances are 2.009 (3) and 1.888 (3) A, respectively.

[Effect of 7 d -6 degrees head-down tilt (HDT) on electromyogram of gastrocnemius and anterior tibialis muscles]

Objective. To assess the effect of 7 d -6 degrees HDT on electromyogram of the weightbearing muscles. Method. Eight healthy males, aged 33-42, were exposed to -6 degrees HDT bed-rest for 7 d, electromyogram from the gastrocnemius and anterior tibialis muscles were recorded before and after HDT, and day 4 of recovery. Result. The latency of SLR (short latency response) recorded from lower leg muscles after HDT was not different from that pre-HDT. But the latency of MLR (middle latency response) and LLR (long latency response) after HDT were significantly increased as compared with that pre-HDT, and recovered to pre-HDT level on day 4 of recovery. The durations of SLR recorded from right leg muscles after HDT were significantly longer as compared with that pre-HDT, and did not recover. The integrated amplitude of SLR and MLR after HDT were significantly increased as compared with that pre-HDT, and only the integrated amplitude of SLR recovered, but that of MLR did not. Conclusion. Seven day -6 degrees HDT bed-rest had significant effects on electromyogram of the weightbearing muscles.

[Effects of 7 d -6 degrees bed-rest on postural equilibrium]

OBJECTIVE

To quantitatively assess the effects of 7 d -6 degrees head-down bed-rest (HDBR) on postural equilibrium and to investigate the contributions of vestibular, somatosensory and visual informations to postural equilibrium.

METHOD

Eight healthy males, aged 33 - 42 years, were exposed to -6 degrees head-down tilt bed rest for 7 d. Sensory Organization Test (SOT) and Motor Coordination Test (MCT) were measured before and after HDBR, and day 4 of recovery.

RESULT

Equilibrium scores of SOT in condition 1 (eyes opened, platform and visual scence environment fixed), 5 (eyes closed visual scence environment fixed, platform movable) were significantly lower as compared with pre-HDBR value, and recovered to pre-HDBR level on day 4 of recovery. Postural strategy scores of SOT in condition 1, 2 (eyes closed, platform and visual scence environment fixed) and 3 (eyes opened, platform fixed, visual scence environment movable) were significantly lower as compared with pre-HDBR value, and recovered to pre-HDBR level on day 4 of recovery. The dependence of somatosensory and visual information (ratio pair codition 2/condition 1, condition 3/condition 1 in sensory analysis) was significantly higher as compared with pre-HDBR value, and recovered on day 4 of recovery. Mean SOT alignment scores in conditions 1, 4 (eyes opened, visual scence environment fixed, platform movable) and 6 (eyes opened, platform and visual scence environment movable) were significantly higher as compared with pre-HDBR value, and only the scores of conditions 1, 6 were recovered on day 4 of recovery, but that of condition 4 did not. Mean postural-evoked response latencies of MCT were not significantly different as compared with pre-HDBR value.

CONCLUSION

7 d -6 degrees head-down tilt bed-rest has significant effects on postural equilibrium. The contributions of somatosensory and visual informations to postural equilibrium are increased.

[The tissue culture of medicinal plant Trichosanthes kirilowii and its protein analysis]

We reported preliminary results of rapid propagation, callus induction and regeneration of Trichosanthes Kirilowii, and its protein analysis. Pre-existing meristerms regenerate shoots very rapidly when grown on MS medium containing 0.5 or 1.0 mg/L 6-BA; calli could be induced from leaf sections when put on MS medium containing 4.0 mg/L 6-BA + 0.2 mg/L IAA; shoots regenerated successfully 30 days after calli induction and the differentiation ratio was one shoot out of every four leaf sections; and all shoots gave rise to roots after removing onto MS medium containing 0.1 mg/L NAA and 100% survived when transplanted into soil. Very excitingly, these plants produced small tubers in one month, where satisfactory expression of TCS protein was detected by Western blot analysis.

[Effects of adaptive changes of vestibular system on cardiovascular regulation and orthostatic tolerance]

Astronauts may experience Space Adaptation Syndrome at the primary period in spaceflight. It is widely accepted that it is mainly caused by vestibular adaptive changes. The reverse changes of adaptation present after the return from weightlessness to normal 1 G. It may cause astronauts' postural instability and orthostatic intolerance. Evidences from animal model and some data from humans suggest that the vestibular system have influences on the sympathetic nervous system and cardiovascular control. The inputs that appear to be critical in producing these responses come from otolith receptors. The important medical problem--orthostatic intolerance in space medicine is mainly caused by cardiovascular abnormal control. It is possible that vestibular adaptive changes under microgravity may have its influence on the cardiovascular function and orthostatic intolerance.

[Analyses of chromosomal karyotypes and cytogenetic variations of animal cell lines]

After the master cell stock(mcs) and working cell bank of more than 30 different strains of 7 animal kidney cell lines (F-81 or CRFK cell line, MDCK cell line, Vero or Vero-2 cell line, MA-104 cell line and BHK-21 cell line) were established in China, the chromosomal number variations and structural aberrations of the above lines, primary feline or canine kidney cell (FKC or CKC) and HeLa cell line were investigated and their karyotypes of routine or Giemsa chromosomal bands were analyzed. The carcinogenesis or tumorigenicity testing of these cells in about 700 nude mice and for colony formation in soft agar (SA) and for agglutination under different concentration of plant lectins was carried out. Both tumorigenicity-negative strains of F-81, CRFK, Vero or Vero-2 lines and very-low-tumorigenicity strains of MDCK line were successfully selected and evaluated for the production of canine or feline combination viral vaccines, which are free of infectious agents, and described with respect to cytogenetic characteristics and tumorigenicity. Rate of modal chromosome number represents the ratio of cell number having modal chromosome number to all the split cell number analyzed at random. Rate of difference represents the ratio of difference of the rate of modal chromosome number between mcs (master cell stock) + n and mcs passages. The chromosomal analysis results showed that the ratio of difference of the rate of modal chromosome number between mcs + n and mcs passages was not more than 5%-15% and the structure aberrations was generally 0%-3%, not more than 5%-10%, thus the hereditary character of cell lines is comparatively stable without significant difference between different passages. The genetic characteristics of chromosomal number of cell lines determines their tumorigenicity, but it is species specific. Experimental models were established for the researches on the prevention and prophylaxis of malignant tumors or cancers and their genetically biological characteristics. Tests showed that there was correlation among cell line chromosome number variations, anchorage independence in soft agar, agglutination under plant lectins and tumor-forming ability in nude mice. Since testing in vitro is more economic, simpler, faster, and is thought to be reliable, we recommend plant lectins followed by SA or analysis of karyotypes as the initial means for monitoring tumorigenicity of animal cell line in nude mice.

Signal velocity, causality, and quantum noise in superluminal light pulse propagation

We consider pulse propagation in a linear anomalously dispersive medium where the group velocity exceeds the speed of light in vacuum ( c) or even becomes negative. A signal velocity is defined operationally based on the optical signal-to-noise ratio, and is computed for cases appropriate to the recent experiment where such a negative group velocity was observed. It is found that quantum fluctuations limit the signal velocity to values less than c.

Delay in light transmission through small apertures

We demonstrate a technique for measuring pulse propagation time delays with 0.5-fs resolution by use of a widely available 100-fs pulsed laser. Using this technique, we measured the time delay of a light pulse transiting through subwavelength apertures placed on a 0.3-mum metallic film. We measured a 7-fs total transit time, corresponding to an effective group velocity of c/7 . The experimental result yielded additional evidence that light interacts resonantly with oscillators formed by the surface modes near the small apertures.

[Cardiac arrhythmias in pilots under positive (+Gz) acceleration]

OBJECTIVE

To study the relationship between cardiac arrhythmias and autonomic nervous regulation in pilots under +Gz acceleration.

METHOD

Dynamic ECG during +Gz exposures in 36 orthostatic intolerance pilots and 62 healthy pilots were analysed and compared.

RESULT

The orthostatic intolerance pilots had obviously lower +Gz tolerance and more cardiac arrhythmias. The cardiac arrhythmias could affect +Gz tolerance.

CONCLUSION

The cardiac arrhythmias under +Gz acceleration could be taken as an index of evaluating cardiovascular compensatory function and warning against acceleration (+Gz) induced loss of consciousness (G-LOC).

MRI of intraosseous dural arteriovenous malformation: findings in two cases

Intraosseous dural arteriovenous malformation (DAVM) is rare. The intraosseous component of this DAVM has usually been neglected on conventional angiography and found during operation after the bone drilling has been completed. Considerable bleeding usually occurs during operation because of the unexpected hypervascular bone marrow. We report the use of MRI to help in the diagnosis and therapeutic plan for this rare type of DAVM.

Preparation and evaluation of insulin-loaded polylactide microspheres using factorial design

The aim of this work was to study the influence of the concentration and molecular weight of poly(DL-lactide) (PLA) on the characteristics and in vivo biological activity of protein-loaded microspheres. At the same time, an attempt was made to achieve further optimization of the formulation. In the study, insulin was chosen as a model of protein drugs. Nine formulations of injectable insulin-loaded PLA microspheres were prepared using an emulsification and solvent evaporation process according to a factorial design. The trapping efficiency, drug loading, and the drop percentages of blood glucose levels at 24 hr and 72 hr in mice were used to evaluate the formulations. The results showed that PLA molecular weight and, especially, PLA concentration exerted influences on the characteristics and in vivo biological activity of insulin-loaded microspheres. The drug-trapping efficiency increased with the increase of the polymer concentration. The drug loading decreased with the increase of the polymer concentration and was not obviously affected by PLA molecular weight. The drop percentage of blood glucose level at 24 hr increased with the increase of polymer concentration and molecular weight. At 72 hr, the drop percentages of blood glucose levels were slightly increased with the increase of PLA concentration and then significantly decreased after the PLA concentration was above 150 mg/ml. An optimized formulation was prepared with PLA-10k at a concentration of 200 mg/ml. The experimental values of the response variables were close to the predicted values. The results suggest that the in vivo release behavior should be taken into consideration in the design of protein-loaded PLA microspheres.

[Effects of some physical training on vestibular function]

Objective. To study the effects of active vestibular conditioning by some physical training on the vestibular function. Method. 10 subjects were given five kinds training gyro wheel, hanging ladder, ripple wood, four column swing and rotating swing for two weeks. Vestibular experimental tests were given before and after training. Result. After physical training, subjects' linear acceleration tolerance time increased significantly, the result of computer dynamic equilibrium posturegraphy demonstrated that the sway of body center of gravity decreased significantly when subjects maintained their equilibrium by both vestibular and visual information. Conclusion. The linear acceleration physical training methods used in this experiment have positive effects, while the methods of angular acceleration training need further investigation.

Enhancement of the activity of l-aspartase from Escherichia coli W by directed evolution

l-Aspartase was modified by directed evolution. After four rounds of error-prone PCR and three rounds of DNA shuffling, an evolved enzyme purified from the final round showed a 28-fold increased k(cat)/K(m) and 4.6-fold decreased K(m). The thermostability and stable pH range were also enhanced. The DNA sequence of the evolved aspartase gene showed seven base changes, resulting in three amino acid changes from the native enzyme: N217K, T233R, V367G. The mechanism of the enhancement of activity was analyzed.

[Mechanism of anti-inflammatory action of Huanglian Jiedu decoction a traditional Chinese prescription]

OBJECTIVE

To elucidate the mechanism of anti-inflammatory action of Huanglian Jiedu Decoction (HJD).

METHODS

An acute inflammatory air-pouch was established in mice by s.c. injecting air and 1% carrageenan. A mouse endotoxeamia induced by lipopolysaccharide was also used. Splenocyte proliferation was quantified with 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetery. NO2- concentration was examined by a Griess reagent and interleukin-1 activity was evaluated in thymocyte proliferation.

RESULTS

HJD significantly inhibited the leukocyte infiltration and PGE2 production in the mouse air-pouch model. In the in vitro assay, HJD significantly inhibited concanavalin A(Con A)-induced transformation of spleen cells isolated from the endotoxeamia mice, but did not influence that from the normal mice. HJD did not affact Con A-induced interleukin-2 production in splenocytes in either normal or endotoxeamia mice. HJD remarkably reduced interleukin-1 and NO production in peritoneal macrophages elicited by lipopol ysaccharide.

CONCLUSION

HJD displays an anti-inflammatory effect mainly through inhibiting the production of inflammatory cytokines including IL-1, NO and PGE2.

[Physiological evaluation of vestibular training load]

Objective. To evaluate the effects of vestibular training by observing the variations of the physiological indices. It is helpful in grasping the training load, setting down and implementing the training plan. Method. 10 healthy subjects received linear acceleration, continuous Coriolis acceleration and discontinuous Coriolis acceleration stimuli on different dates. The stimulus was stopped when there were slight autonomic nervous symptoms, ECG, EGG and BP were recorded before during and after the stimuli. Computerized Dynamic Posturography (correction of Postrograph) (CDP) was tested before and after experiment. Result. One subject finished the training of the three stimuli with only slight autonomic nervous symptoms. The CDP tests pre- and post-experiment indicated that for most subjects the contribution of vestibular function in maintaining dynamic posture equilibrium increased after the linear acceleration stimuli, but decreased after continuous Coriolis acceleration stimuli, and there was great individual difference after discontinuous Coriolis acceleration stimuli because the stimulation was relatively heavy. The equilibrium score in SOT2 decreased significantly after linear acceleration stimuli, and increased significantly after discontinuous Coriolis acceleration stimuli. Conclusion. The training methods we designed and used in this experiment are feasible, and the required training load can be reached. EGG, BP and the percentage of LF (low frequency) in ECG R-R power spectrum can reflect the subject's condition when the period stimuli stopped. It provided important reference in the determination of training stimulation load.

A study of postoperative radiotherapy in patients with non-small-cell lung cancer: a randomized trial

PURPOSE

To study the value of postoperative radiotherapy for non-small-cell lung cancer (NSCLC) with positive regional lymph metastases (NI or N2) after radical surgery.

MATERIALS AND METHODS

From February 1982 to October 1995, 366 patients with NSCLC and N1 or N2 disease were randomized into postoperative radiotherapy (S + R) (183 patients) and no further treatment (S alone) (182 patients). Postoperative radiotherapy (RT) was administrated 3-4 weeks after radical operation. Irradiated fields covered the bronchial stump, ipsilateral hilum, and most of the mediastinum. The midplane dose was 6000 cGy/30 fractions/6 weeks, with the spinal cord limited to 4000 cGy/20 fractions/4 weeks or less. One hundred thirty-four patients in S + R group and 162 patients in S alone group were evaluated. Clinical data were comparable in both arms, except for the numbers of N2 patients.

RESULTS

The 3-year and 5-year overall survival rates were 51.9% and 42.9% in the S + R group and 50.2% and 40.5% in the S alone Group (p = 0.56). The 3-year and 5-year disease-free survival rates were 50.7% +/- 4.7% and 42.9% +/- 5.2% in the S + R group vs. 44.4% +/- 4.3% and 38.2% +/- 4.5% in the S alone group (p = 0.28), respectively. In the patients with NI or T3-4 tumors, there was a trend toward improved survival in the S + R group, especially in the patients with T3-4N1M0. These patients demonstrated 20% improvement in overall survival (p = 0.092) and greater than 20% better disease-free survival (p = 0.057). Postoperative RT reduced local recurrence but had no impact on distant metastases.

CONCLUSION

Postoperative RT significantly reduced local relapses, but did not improve overall survival, due to a high frequency of distant metastases in this patient group.

Mortality after successful transcatheter arterial embolization in patients with unstable pelvic fractures: rate of blood transfusion as a predictive factor

BACKGROUND

To determine the factors predictive of mortality in patients with unstable pelvic fractures after successful transcatheter arterial embolization.

METHODS

A retrospective study of pelvic fractures between May of 1995 and April of 1998 was performed. Of 507 patients, 17 who were unstable underwent embolization. The success rate of embolization and the mortality rate after successful embolization were reviewed. Predictive factors (contrast medium extravasation, initial blood pressure, Injury Severity Score, timing of external fixation, time to angiography, volume of blood transfusion, rate of blood transfusion) of the final outcome were statistically analyzed.

RESULTS

Embolization was 100% effective in stopping pelvic hemorrhage. The mortality of patients treated successfully with embolization was 17.6%. Among the predictive factors analyzed, only the rate of blood transfusion before embolization, 11.3 +/- 11.0 units/h (death) versus 3.2 +/- 1.9 units/h (survival) showed statistical significance with an odds ratio of 1.62 (95% confidence interval, 1.07-2.46).

CONCLUSION

The success rate of embolization was 100% in stopping arterial hemorrhage of unstable pelvic fractures. The survival rate after successful embolization was 82.4%. Patients who had rapid blood transfusion before embolization had a poor final outcome. The risk of dying increased by 62% for every 1 unit/h increase of transfusion rate.

[c-fos expression in rat's vestibular nucleus under eccentric rotational stimulation]

OBJECTIVE

To investigate the c-fos expression in rat's vestibular nucleus under eccentric rotational stimulation and the effects of anti-motion sickness drug (PAPM) on this expression.

METHOD

19 SD rats were divided into three groups: A, B and C. A received as control. B was stimulated by eccentric rotation for 60 minutes. C received injection of PAPM through cavun abdominis 45 min before eccentric rotation. Immunohistochemical method and computerized image analysis were used to map locations of c-fos protein appeared in four vestibular nucleus and to count the masculine cells.

RESULT

c-fos protein appeared in four vestibular nucleus areas after stimulation, and PAPM had no influence on this expression.

CONCLUSION

It suggests that c-fos expression in vestibular nucleus is one of the important way in which vestibular nervous system reacts to outside stimulation and this expression has no direct relationship with the generation and development of motion sickness.

The impact of overall treatment time on outcomes in radiation therapy for non-small cell lung cancer

PURPOSE

A retrospective study was carried out to evaluate the impact of overall treatment time (OTT) on the results of radiation therapy for non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

From Jan. 1990 to Dec. 1996, 256 patients with stages I-IIIb NSCLC entered this analysis. All patients received definitive radiotherapy. Biologically effective dose (BED) was used to standardize the irradiation effects. The correlation between OTT and local progression-free survival was analyzed by linear-regression and Cox proportional hazard models. The prognostic variables for survival and distant metastasis were also briefly studied.

RESULTS

OTT had been shortened in 64 patients because of an accelerated hyperfractioned irradiation, while OTT was prolonged i n 114 patients due to interruptions of irradiation courses. The main ca uses of interruption were machine breakdown or delayed preparations of c errobend block for boost fields (55%), holidays (11%) and treatment toxi city and side effects (34%). Patients tre ated with prolonged OTT (> 45 days) had significant poorer local progression-free survival than whom with OTT of </=45 days, 1, 3 and 5 year actuarial local progression-free survivals being 49, 17 and 15% for the former, and 74, 35 and 25% for the latter, respectively (P<0.001). BED-T that contained the factor of OTT correlated directly to local controls, which implied that BED-T represented radiobiological effects accurately, in other words, OTT had played a role in determining the radiobiological effects. Linear-regression on 103 cases treated with BED of 80-85 Gy(10) showed that 3 year local progression-free survival decreased by 9% per week with prolongation of OTT, or vice versa it increased by 9% per week with shortening OTT in an OTT range of 30-76 days. Cox multivariate analyses confirmed that OTT was an independent prognostic factor for local controls.

CONCLUSION

OTT may have played an important role in determining local controls in radiotherapy for NSCLC. One should always keep in mind to make the OTT as short as possible, provided the patients can tolerate it, and to reduce irradiation interruptions for whatever reasons to a minimum.

Image data compression using cubic convolution spline interpolation

A new cubic convolution spline interpolation (CCSI )for both one-dimensional (1-D) and two-dimensional (2-D) signals is developed in order to subsample signal and image compression data. The CCSI yields a very accurate algorithm for smoothing. It is also shown that this new and fast smoothing filter for CCSI can be used with the JPEG standard to design an improved JPEG encoder-decoder for a high compression ratio.

Regulation of the renal Na-HCO(3) cotransporter. XI. Signal transduction underlying CO(2) stimulation

We have previously shown that CO(2) stimulation of the renal Na-HCO(3) cotransporter (NBC) activity is abrogated by general inhibitors of protein tyrosine kinases. The more selective inhibitor herbimycin also blocked this effect at concentrations known to preferentially inhibit Src family kinases (SFKs). We therefore examined a role for SFKs in CO(2)-stimulated NBC activity. To this end, we engineered OK cells to express the COOH-terminal Src kinase (Csk), a negative regulator of SFKs. CO(2) stimulated NBC activity normally in beta-galactosidase-expressing and untransfected control cells. In contrast, Csk-expressing cells had normal baseline NBC activity that was not stimulated by CO(2). CO(2) stimulation increased both total SFK activity and specific tyrosine phosphorylation of Src. The specific MEK1/2 inhibitor PD-98059 completely inhibited the CO(2) stimulation of NBC activity as well as the accompanying phosphorylation and activation of ERK1/2. Our data suggest the involvement of both SFKs, probably Src, and the "classic" MAPK pathway in mediating CO(2)-stimulated NBC activity in renal epithelial cells.

[Ocular counterrolling as an indicator of vestibular otolith function]

Space Motion Sickness (SMS) occurred in the first few days of space flight correlated with the vestibular function. As the main influence of weightlessness in space focused on the otolith receptors. The test of otolith function is of great importance. Although there are a lot of methods to test otolith function, at present ocular counterrolling is the only relative pure indicator of otolith function. It provide a valid method for predicting SMS susceptibility, it has great application prospect in the research of the SMS mechanism and the readaptability of vestibular function after space flight, it also provides great reference in the clinical diagnosis of vestibular problems.

Skeletal muscle calcium channel ryanodine binding activity in genetically unimproved and commercial turkey populations

The biochemical basis for the incidence of pale, soft, exudative (PSE) turkey meat was investigated by conducting ryanodine binding experiments on sarcoplasmic reticulum (SR) vesicles prepared from genetically unimproved and commercial turkeys. Ryanodine binding to the Ca2+ channel protein in SR vesicles from both populations of turkeys was activated at a threshold concentration of approximately 0.2 microM Ca2+, reached a plateau over the range of 3 to 30 microM free Ca2+, and was only slightly inhibited at 1 mM Ca2+. The SR fractions, enriched in the Ca(2+)-channel protein, from commercial turkeys exhibited a higher (P < 0.05) mean affinity for ryanodine when compared to that from unimproved turkeys (Kd = 12.2 vs 20.5 nM, respectively). A fourfold difference (P < 0.05) in mean Ca(2+)-channel protein content or Bmax (1.10 pmol/mg vs 4.01 pmol/mg) was observed between commercial and unimproved turkey SR fractions. The apparent difference in channel protein content between the two populations may be partially accounted for by the high abundance of a 75-kDa protein, as yet unidentified, observed in most commercial turkey samples on SDS polyacrylamide gels. The differences in ryanodine binding activity between these two populations of turkeys suggest that altered SR calcium channel protein activity, or altered channel regulation, may be associated with the increased incidence of PSE meat from turkeys selected for growth characteristics.

S-adenosylmethionine synthetase is overexpressed in murine neuroblastoma cells resistant to nucleoside analogue inhibitors of S-adenosylhomocysteine hydrolase: a novel mechanism of drug resistance

S-Adenosylmethionine (AdoMet) synthetase (EC 2.5.1.6), which catalyzes the synthesis of AdoMet from methionine and ATP, is the major methyl donor for transmethylation reactions and propylamino donor for the biosynthesis of polyamines in biological systems. We have reported previously that wild-type C-1300 murine neuroblastoma (wMNB) cells, made resistant to the nucleoside analogue (Z)-5'-fluoro-4',5'-didehydro-5'-deoxyadenosine (MDL 28,842), an irreversible inhibitor of S-adenosylhomocysteine (AdoHcy) hydrolase (EC 3.3.1.1), express increased AdoMet synthetase activity (M. R. Hamre et al., Oncol. Res., 7: 487-492, 1995). In the present study, immunoblot analyses of AdoMet Synthetase with isoform-specific (MATII) antibodies demonstrated an elevation in the AdoMet synthetase immunoprotein in nucleoside analogue-resistant MNB cells (rMNB-MDL) when compared to wild-type, nonresistant MNB cells. An increase of 2.1-fold was observed in the alpha2/alpha2' catalytic subunit, which differed significantly from the much smaller increment in the noncatalytic beta-subunit of AdoMet synthetase. Densitometric analyses revealed that an increased expression of AdoMet synthetase in rMNB-MDL cells was due to overexpression of the alpha2 (Mr 53,000; 2.6-fold) and alpha2' (Mr 51,000; 1.8-fold) subunits. AdoMet synthetase mRNA expression in rMNB-MDL cells was remarkably greater than wMNB cells, as determined by quantitative competitive reverse transcription-PCR (QC-PCR) analysis. DNA (cytosine) methyl transferase expression, measured by reverse transcription-PCR analysis, was also elevated significantly in rMNB-MDL cells. In contrast, Western blot analyses demonstrated down-regulation (1.6-fold) of AdoMet synthetase in doxorubicin-resistant human leukemia cells (HL-60-R) expressing multidrug resistance protein when compared with wild-type, nonresistant HL-60 cells. The resistance of rMNB-MDL cells to nucleoside analogue inhibitors of S-adenosylhomocysteine hydrolase correlates directly with overexpression of the alpha2/alpha2' subunits of AdoMet synthetase. Cellular adaptation allows sufficient AdoMet to be synthesized, so that viability of the MNB cells can be maintained even in the presence of high AdoHcy concentrations. This novel mechanism of drug resistance does not appear to require multidrug resistance protein (P-glycoprotein) overexpression.

Velvet antler polypeptides promoted proliferation of chondrocytes and osteoblast precursors and fracture healing

AIM

To study the effects of velvet antler (VA) total polypeptides (VATP) and VA polypeptides, VAP-A, VAP-B, and VAP-C on proliferation of chondrocytes and osteoblast precusors.

METHODS

Chondrocytes (rabbit and human fetus) and osteoblast precusors (chick embryo) were incubated in the culture medium containing VATP or VAP-A, VAP-B, and VAP-C. [3H]TdR incorporation into DNA was measured. Fracture healing-promoting action of VATP was determined in rats.

RESULTS

VATP 50-200 mg.L-1 and VAP-B 12.5, 25, and 50 mg.L-1 showed most marked proliferation-promoting activity for rabbit costed chondrocytes and increased incorporation of [3H]TdR from (73 +/- 9) Bq (control group) to (272 +/- 55), (327 +/- 38), and (415 +/- 32) Bq, respectively (P < 0.01). The activity of VAP-A was weaker than that of VAP-B, and VAP-C had no activity. VATP 10 and 20 mg.kg-1 by local injection into the cross-section fracture area accelerated healing of radial fracture. The healing rate of VATP-treated group was higher (75%) than that of control group (25%) (P < 0.05).

CONCLUSION

VATP accelerated fracture healing by stimulating proliferation of chondrocytes and osteoblast precursors.

[Preliminary studies on tissue culture and agrobacterium-medicated transformation of Brassica campestris ssp. chinensis]

The hypocotyls and cotyledons of the asepetic seedling of Brassica campestris ssp. chinensis L cv. Pudongaijiecai) were used as explants for tissue culture. Adventitious buds were differentiated on modified MS medium supplemented with TDZ 1-2 mg/L, NAA 0.2-1 mg/L and AgNO3 7.5 mg/L. The percentage of explants which formed buds of cotyledons was about 56%, and that of hypocotyls was about 37%. When the regenerated explants were transferred onto MS medium with 2 i.p. 5 mg/L and NAA 0.1 mg/L for two weeks, whole plantlets were obtained by culturing the regenerated shoots on 1/2 MS medium with NAA 0.1 mg/L. Agrobacterium tumefaciens strain (LBA 4404/PBI 121) carrying the GUS gene and Npt II gene was used for transformation. After 2 days of coculture, the hypocotyls and cotyledons were transferred onto regenerated medium containing CP 300 mg/L for bud formation. After 4-5 weeks, the differentiated buds were transferred onto selection medium with CP 200 mg/L and Km 10 mg/L for 1 month, then the green shoots were transferred onto the rooting medium containing Cef 100 mg/L and Km 20 mg/L. 4-5 weeks later, plantlets with Km resistance were obtained and some of them showed higher enzymatic activities of beta-glucuronidase than control ones.

Foliar modifications induced by inhibition of polar transport of auxin

The effects of auxin polar transport inhibitors, 9-hydroxy-fluorene-9-carboxylic acid (HFCA); 2, 3, 5-triiodobenzoic acid (TIBA) and trans-cinnamic acid (CA) on leaf pattern formation were investigated with shoots formed from cultured leaf explants of tobacco and cultured pedicel explants of Orychophragmus violaceus, and the seedlings of tobacco and Brassica chinensis. Although the effective concentration varies with the inhibitors used, all of the inhibitors induced the formation of trumpet-shaped and/or fused leaves. The frequency of trumpet-shaped leaf formation was related to the concentration of inhibitors in the medium. Histological observation of tobacco seedlings showed that there was only one main vascular bundle and several minor vascular bundles in normal leaves of the control, but there were several vascular bundles of more or less the same size in the trumpet-shaped leaves of treated ones. These results indicated that auxin polar transport played an important role on bilateral symmetry of leaf growth.