Real time PCR on disposable PDMS chip with a miniaturized thermal cycler

This paper presents the design and implementation of a low-cost miniature PCR device consisting of a disposable reactor chip and a miniature thermal cycler. The simple fabrication of the PCR chip by PDMS (Polydimethylsiloxane) does not need micro-machining or photolithography processes. The thermal cycler was built with a thin film heater for heating and a fan for rapid cooling. This device can perform PCR tests in a single well chip or a multiple-well chip. It can run PCR reactions of different volumes to meet specific application requirements. The smallest reaction volume tested in this work is 0.9 microL. In addition, this device fits any standard fluorescence microscope for real time detection, which makes real time PCR affordable for most research labs and clinics with a fluorescence microscope. Real-time PCR of E. coli stx1 has been demonstrated with the device described.

Ultra-wide bore 900 MHz high-resolution NMR at the National High Magnetic Field Laboratory

Access to an ultra-wide bore (105 mm) 21.1 T magnet makes possible numerous advances in NMR spectroscopy and MR imaging, as well as novel applications. This magnet was developed, designed, manufactured and tested at the National High Magnetic Field Laboratory and on July 21, 2004 it was energized to 21.1 T. Commercial and unique homebuilt probes, along with a standard commercial NMR console have been installed and tested with many science applications to develop this spectrometer as a user facility. Solution NMR of membrane proteins with enhanced resolution, new pulse sequences for solid state NMR taking advantage of narrowed proton linewidths, and enhanced spatial resolution and contrast leading to improved animal imaging have been documented. In addition, it is demonstrated that spectroscopy of single site (17)O labeled macromolecules in a hydrated lipid bilayer environment can be recorded in a remarkably short period of time. (17)O spectra of aligned samples show the potential for using this data for orientational restraints and for characterizing unique details of cation binding properties to ion channels. The success of this NHMFL magnet illustrates the potential for using a similar magnet design as an outsert for high temperature superconducting insert coils to achieve an NMR magnet with a field >25 T.

Increased persistent Na(+) current and its effect on excitability in motoneurones cultured from mutant SOD1 mice

Mutations in the enzyme superoxide dismutase 1 (SOD1) initiate a progressive motoneurone degeneration in amyotrophic lateral sclerosis (ALS). Transgenic mice overexpressing this mutation develop a similar progressive motoneurone degeneration. In spinal motoneurones cultured from presymptomatic mice expressing the glycine to alanine mutation at base pair 93 (G93A) SOD1 mutation, a marked increase in the persistent component of the Na(+) current was observed, without changes in passive properties. This increase only enhanced neuronal excitability in high input conductance cells, as low input conductance cells exhibited a compensatory outward shift in the current remaining after Na(+) blockade. High input conductance motoneurones tend to be large, so these results may explain the tendency of large motoneurones to degenerate first in ALS. Riluzole, at the therapeutic concentration used to treat ALS, decreased neuronal excitability and persistent Na(+) current in G93A motoneurones to levels observed in the control motoneurones. Aberrations in the intrinsic electrical properties may be among the first symptoms to emerge in SOD1-linked ALS.

Skin temperature recovery from cold provocation in workers exposed to vibration: a longitudinal study

BACKGROUND

Vibration white finger (VWF) is characterised by arterial hyperresponsiveness and vasoconstriction following cold provocation. Several years after of removal from exposure, most subjects show improved finger systolic blood pressure (FSBP) under conditions of cold challenge, but continue to report cold hands and finger blanching.

AIMS

To assess the underlying reasons for the persistence of cold symptoms.

METHODS

A total of 204 former users of pneumatic tools with cold related hand symptoms were evaluated and then re-evaluated a year later. Symptoms were evaluated using the Stockholm Workshop Scale. Finger systolic blood pressure per cent (FSBP%) was assessed by comparing digital blood pressure in a cold provoked and normalised state. Fingertip skin temperature was measured during cooling and occlusion and during rewarming and recovery.

RESULTS

There were dramatic improvements in FSBP% (14.3 mm Hg %), modest improvement in recovered skin temperature (0.86 degrees C), and no change in symptom stage. When the most symptomatic subjects (n = 75) were compared with the less symptomatic subjects (n = 129), there were similar inter-test improvements in FSBP%. Skin temperature recovery improved in the less symptomatic (+1.49 degrees C), but did not change in the most symptomatic group (-0.12 degrees C). However, the more symptomatic group had higher temperatures at the initial test, thus qualifying the result.

CONCLUSIONS

Skin temperature recovery after cold challenge in subjects with VWF remains reduced in the symptomatic subjects several years after exposure removal. This is evident even when blood pressure has increased in the setting of cold provocation. Results suggest that in VWF, the dermal circulation remains impaired, even after the restoration of arterial blood pressure in the digits.

Functional polymer affinity matrix for purifying hexahistidine-tagged recombinant protein

A functional polyacrylic acid (PAA) adsorbent has been prepared for metal chelate affinity chromatography. It has been found to chelate nickel ion Ni2+ strongly, and was evaluated for the ability to bind proteins containing neighbouring histidine residues. The principle of the technique was illustrated with Aeromonas hydrophila outer membrane protein OmpTS. DNA elements coding for adjacent histidines were fused to the Aeromonas hydrophila ompTS gene. Subsequent expression in E. coli resulted in the production of hybrid protein His6-OmpTS that could be purified by Ni2+-PAA affinity chromatography. The remarkable specificity found makes it an attractive addition to the range of adsorbents for metal chelate affinity chromatography.

Assessment of various topical oral formulations by bone marrow transplant recipients

Topical approaches to management of oral mucositis have the advantages of high local concentration and limited or no systemic absorption, reducing the risk of systemic complications. The acceptability of topical therapies in cancer patients has not been evaluated. Thirty-eight transplant patients assessed the acceptability of three formulations (rinse, thin gel, thick gel) of a new compound developed to prevent oral mucositis. The rinse was selected as the most acceptable formulation. The thick gel received the lowest rating. Consistency was a major determinant of overall acceptability. A neutral taste was desirable for most participants. Room temperature of the formulation was rated as completely acceptable. Most participants would be willing to use the rinse or thin gel several times per day, to retain each dose in the oral cavity for up to 5 min, and to swallow it. The support of caregivers may be needed to achieve compliance with such regimens.

Imaging membrane protein helical wheels

Resonance patterns have been observed in 2D solid-state NMR spectra of the transmembrane segment of M2 protein from Influenza A virus in oriented samples reflecting the helical wheel of this alpha-helix. The center of this pattern uniquely defines the helical tilt with respect to the bilayer normal without a need for resonance assignments. The distribution of resonances from amino acid specific labels around the "PISA wheel" defines the rotational orientation of the helix and yields preliminary site-specific assignments. With assignments high-resolution structural detail, such as differences in tilt and rotational orientation along the helical axis leading to an assessment of helical coiling, can be obtained.

Inter- and intramolecular distance measurements by solid-state MAS NMR: determination of gramicidin A channel dimer structure in hydrated phospholipid bilayers

Distance constraints are an important complement to orientational constraints. While a high-resolution monomer structure of the ion channel forming polypeptide, gramicidin A, has been solved with 120 orientational constraints, the precise geometry of the dimer interface has not been characterized. Here, using both 13C and 15N labeled gramicidin A samples in hydrated phospholipid bilayers, both inter- and intramolecular distances have been measured with a recently developed simultaneous frequency and amplitude modulation (SFAM) solid-state NMR scheme. Using this approach 15N-13C1 residual dipolar couplings across a hydrogen bond as small as 20+/-2 Hz have been characterized. While such distances are on the order of 4.2+/-0.2 A, the spectroscopy is complicated by rapid global motion of the molecular structure about the bilayer normal and channel axis. Consequently, the nominal 40 Hz dipolar coupling is averaged depending on the orientation of the internuclear vector with respect to the motional axis. The intermolecular distance confirmed the previously described monomeric structure, while the intramolecular distance across the monomer-monomer interface defined this junction and confirmed the previous model of this interface.

[The lymphocyte subset and blood interleukin-2 level in children with Henoch-Schönlein purpura before and after cimetidine treatment]

The objective of this study was to evaluate the effect of cimetidine treatment on cellular immunity in children with Henoch-Schönlein purpura. T cell subset was detected by double marker flow cytometry and the level of IL-2 in peripheral blood was measured by MTT method, before and after cimetidine treatment. The results showed that CD3+, CD4+ T cell subset, CD4+/CD8+ ratio, and blood IL-2 level increased after the treatment (P < 0.05). There was no significant change in CD8+ T subset after the treatment. These findings indicate that cimetidine can promote T lymphocyte proliferation and differentiation, especially TH1 lymphocyte activity.

[Detection of DNA variation after space flight in Datura innoxia by random amplified polymorphic DNA markers]

OBJECTIVE

To substantiate the effect of space environment on medicinal plants, the seeds of Datura innoxia were set up in retrievable satellites.

METHODS

After returning to earth, the DNA variation of different groups was detected by random amplified polymorphic DNA (RAPD) markers.

RESULTS

From a pre-screening of 65 primers with 20 oligonucleotide lengths, 15 primers that produced distinct profiles for each DNA sample were selected. In contrast with the earth controlled group, 39 polymorphic bands were produced in weightless group, and its degree of gene polymorphism was 23.1%; 45 polymophic bands were produced in hit group, and its degree of gene polymorphism was 24.4%. The polymorphic bands ranged approximately from 200 to 1990 bp.

CONCLUSIONS

These results indicate that weightlessness induce DNA variation to some extents in Datura innoxia, while the compound effect of weightlessness and high energy heavy ions is more notable than the effect of single weightlessness.

[Effect of space flight on ultrastructure of chloroplast in Agastache rugosa]

OBJECTIVE

To substantiate the effects of space condition on medicinal plants, the seeds of Agastache rugosa were set up in retrievable satellites.

METHODS

After returning to earth, the ultrastructural changes of chloroplasts were examined by means of electron microscope.

RESULTS

Vesicles could be seen in the chloroplasts in the cells of earth controlled group, it was few and could not be found in the chloroplasts in the cells of weightless group and hit group. Some chloroplasts were degrading in the cells of weightless group, but this phenomenon was not observed in the cells of the other two groups.

CONCLUSIONS

These results showed that space environment had some effect on the ultrastructure of chloroplasts in Agastache rugosa.

Correlations of structure, dynamics and function in the gramicidin channel by solid-state NMR spectroscopy

The high resolution structure of the gramicidin A channel has been determined in a lamellar phase environment using solid-state NMR spectroscopy. While the fold is similar to previous characterizations, channel function is exquisitely dependent on structural detail. There is essentially no structural change upon cation binding and no significant change in dynamics. The cations appear to be adequately solvated in their binding site by no more than two carbonyls and no fewer than three water molecules at any one time. The relatively large number of water molecules allows for geometric flexibility and little selectivity among monovalent cations. However, the dehydration energies of cations clearly explain the selectivity for monovalent versus divalent cations. Moreover, the binding site is shown to be delocalized, resulting in a shallow potential energy well so that efficient cation conductance can be realized. The potential energy barrier at the bilayer centre has been shown to be rate limiting under certain circumstances through a correlation between conductance and the electrostatic interactions between cations at the gramicidin monomer-monomer junction and the indole dipole moments at the lipid-water interface. The dynamics are functionally important. The time-scale for carbonyl fluctuations about the C alpha-C alpha axis and kinetic rates for cation movement in the channel are the same, suggesting a correlation between molecular dynamics and kinetics. These functional correlations will be described in light of the recent K+ channel structure and the biological challenge to achieve both selectivity and efficiency.

[The advances of the study on the optical chromatography]

This review is mainly concerned with the recent developments in (1) the differences between the optical tweezer and optical chromatography; (2) the principle of optical chromatography separation; (3) the theory studies on the optical chromatography, especially the relationship between the particle radius with the intensity of the applied laser radiation force and the relationship between the particle retention distance with the particle radius; (4) the application of the optical chromatography technique to the separation of polymers, biological macromolecules and biological cells. The application of optical chromatography to the immunoassy and molecular biology is highlighted.

Hahn-echoes from 14N in solids by the stray-field method: prospects for imaging using Long Echo-Train Summation

We have observed Hahn-echoes resulting from Powles-Mansfield pulse-sequences for a variety of nitrogen containing solids which exhibit a range of 14N electric quadrupole coupling constants (Cq) from 0 to 4.9 MHz. Long echo-decays were frequently obtained which allowed the collection of many echoes in one echo-train, so that the method of Long Echo-Train Summation (LETS), could be used to accumulate signal. A one-dimensional STRAFI-profile is shown for solid ammonium nitrate. The spatial resolution is discussed as a function of Cq.

13C selective polarization and spin diffusion in a lipid bilayer-bound polypeptide by solid-state NMR

While (15)N solid-state NMR has proven to be very advantageous for the development of structural biological methods, (13)C spectroscopy has increased sensitivity and spectral dispersion. However, large natural abundance signals and homonuclear dipolar interactions pose significant problems. Here we have used a pair of (13)C-labeled sites in a lipid-solubilized polypeptide to show the selective polarization can be used in combination with spin diffusion to achieve simplified spectra. Both unoriented and oriented samples have been used, with the latter providing a well-resolved homonuclear dipolar splitting.

Solid-state nuclear magnetic resonance investigation of protein and polypeptide structure

Solid-state nuclear magnetic resonance (NMR) is rapidly emerging as a successful and important technique for protein and peptide structural elucidation from samples in anisotropic environments. Because of the diversity of nuclei and nuclear spin interactions that can be observed, and because of the broad range of sample conditions that can be studied by solid-state NMR, the potential for gaining structural constraints is great. Structural constraints in the form of orientational, distance, and torsional constraints can be obtained on proteins in crystalline, liquid-crystalline, or amorphous preparations. Great progress in the past few years has been made in developing techniques for obtaining these constraints, and now it has also been clearly demonstrated that these constraints can be assembled into uniquely defined three-dimensional structures at high resolution. Although much progress toward the development of solid-state NMR as a routine structural tool has been documented, the future is even brighter with the continued development of the experiments, of NMR hardware, and of the molecular biological methods for the preparation of labeled samples.

Capillary electrophoresis enantioseparation of drugs using beta-cyclodextrin polymer: intramolecular synergistic effect

Enantiomers of eight basic compounds of pharmaceutical interest were studied by capillary electrophoresis (CE) using a soluble cyclodextrin (CD) polymer and native CD as chiral selectors. The effects of the polymer concentration and the pH of the buffer solution on resolution were examined. It was found that the beta-CD polymer shows higher stereoselectivity than its parent cyclodextrin. Such improvement is due to the structural difference between beta-CD and beta-CD polymer. These results suggested the existence of an intramolecular synergistic effect in CE.

[Effect of space flight on ultrastructure in medicinal plant Datura innoxia Mill]

OBJECTIVE

To substantiate the effect of space environment on medicinal plants.

METHOD

The seeds of Datura innoxia were set up in retrievable satellites. After returning to earth, the ultrastructural changes were observed by means of electron microscope.

RESULTS

In cells of weightless group and hit group, some changes were found in chloroplast grana, starch grains and vesicles in chloroplasts. No obvious changes were observed in nuclei.

CONCLUSION

Space environment has some effect on the ultrastructure in D. innoxia, and chloroplast is more sensitive to space environment than other organs.

Vicia root micronucleus assay on the clastogenicity of water samples from the Xiaoqing River in Shandong Province of the People's Republic of China

Vicia root micronucleus assay was used to determine the clastogenicity of water samples from Xiaoqing River that passes through Jinan City. Positive results were obtained from eight water collecting sites. This indicates that the water in most areas of this river was polluted with industrial waste and municipal sewage. Results of this study proves that biomonitoring with Vicia root micronucleus test is an efficient way to assess the water quality of this river.

[The application of expanded polytetrafluoroethylene in the treatment of facial depression with facial nerve palsy]

OBJECTIVE

In order to investigate the effect of expanded polytetrafluoroethylene (e-PT-FE) in repair of facial depression.

METHODS

From February 1997 to July 1998. The e-PTFE was used as a filling and suspending material for facial depression and facial nerve palsy in 6 cases. They were followed up for 2-16 months.

RESULTS

After filling of the facial depression, the deformed side of the face became symmetrical to that of contralateral side, and those following the suspending technique using this material the affected eyelids could close completely and the oral corners were symmetrical in its static status.

CONCLUSION

The expanded PTFE was a safe, biocompatible and easily applied material, especially served as a filling or suspending material in the repair of facial depression with facial nerve palsy.

Solid-state NMR and hydrogen-deuterium exchange in a bilayer-solubilized peptide: structural and mechanistic implications

Hydrogen-deuterium exchange has been monitored by solid-state NMR to investigate the structure of gramicidin M in a lipid bilayer and to investigate the mechanisms for polypeptide insertion into a lipid bilayer. Through exchange it is possible to observe 15N-2H dipolar interactions in oriented samples that yield precise structural constraints. In separate experiments the pulse sequence SFAM was used to measure dipolar distances in this structure, showing that the dimer is antiparallel. The combined use of orientational and distance constraints is shown to be a powerful structural approach. By monitoring the hydrogen-deuterium exchange at different stages in the insertion of peptides into a bilayer environment it is shown that dimeric gramicidin is inserted into the bilayer intact, i.e., without separating into monomer units. The exchange mechanism is investigated for various sites and support for a relayed imidic acid mechanism is presented. Both acid and base catalyzed mechanisms may be operable. The nonexchangeable sites clearly define a central core to which water is inaccessible or hydroxide or hydronium ion is not even momentarily stable. This provides strong evidence that this is a nonconducting state.

[The novel copolymer coated capillary columns of electrophoresis and their applications to separation of proteins]

The copolymer of acrylonitrile, methyl acrylate, hydroxy ethyl acrylate (ZB-004), the copolymer of acrylonitrile, methyl acrylate, hydroxy ethyl acrylate, acrylamide (ZB-014) and the copolymer of acrylonitrile, hydroxy ethyl acrylate (ZB-016) were coated on the inner surface of fused-silica capillaries by just filling the capillary with solutions containing these copolymers followed by flushing the capillary with nitrogen. The physically adsorbed layer can reduce both protein adsorption and electroosmotic flow in the pH range of 3-5. Electroosmotic flow decreased by raising the concentrations of the copolymers. Separation performance of ZB-004 layer is better than those of other two layers due to its low hydrophilicity, but with higher pH values, appreciable peak deformation and increase in electroosmosis were observed. The intra day and inter day migration reproducibility were investigated in terms of relative standard deviation (RSD) with four basic proteins at pH 4.0. The RSDs of the intra day migration times were less than 2%. The RSDs of the inter day migration times were less than 4%. At pH 5.0, the RSDs of the migration times in two ZB-004-coated capillaries made on two different days were less than 1%. Separation efficiencies of four basic proteins in a ZB-004-coated capillary which stored in a buffer (pH 4.0) for fifteen days after being used for 14 days decreased 15%. These coatings were stable and exhibited reproducible separations from intra day, inter day and inter column under acidic conditions.

[Separation of alkaloids in tea by high-speed counter-current chromatography]

Alkaloids extracted from the green tea were separated by high-speed counter-current chromatography. A series of experiments have been performed to investigate effects of different solvent system. A system of CHCl3-CH3OH-NaH2PO4(23 mmol/L) = (4:3:2) was selected, in which the upper phase was used as the stationary phase, and the lower phase as mobile phase. When acidity of solvent system is pH 5.6, three chemical components are very efficiently isolated by one injection of 50 mg sample mixture. Analyzing the eluted fractions by TLC, we know that one is caffeine, and the other is theophylline. In comparing the separation results by high-speed counter-current chromatography with those by TLC, the advantages of this method is verified. It should find wide applications of this technology for the separation of crude mixture of plant components.

Design of efficient lens ducts

Lens ducts have the potential to couple the output from a laser diode array efficiently into the gain medium of a solid-state laser in an end-pumped configuration. Using a ray-tracing method we investigate different design approaches of lens ducts and demonstrate the possibility to obtain an output beam with a symmetric profile that is insensitive to the small displacement from the output surface of a lens duct.

[Preliminary analysis and isolation of genomic total DNA in Fritillaria thunbergii Miq]

Genomic total DNA of leaf, fresh scale and dry scale in Fritillaria thumbergii were isolated by two different methods and analysed by agarose gel electrophoresis. The results show that the DNA contents are different under these two isolating methods. Two bands besides the band of genomic total DNA have been found by electrophoresis, these two bands deserve further study.

ISD1, an insertion element from the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough: structure, transposition, and distribution

Insertion element ISD1, discovered when its transposition caused the insertional inactivation of an introduced sacB gene, is present in two copies in the genome of Desulfovibrio vulgaris Hildenborough. Southern blot analysis indicated at least two insertion sites in the sacB gene. Cloning and sequencing of a transposed copy of ISD1 indicated a length of 1,200 bp with a pair of 44-bp imperfect inverted repeats at the ends, flanked by a direct repeat of the 4-bp target sequence. AAGG and AATT were found to function as target sequences. ISD1 encodes a transposase from two overlapping open reading frames by programmed translational frameshifting at an A6G shifty codon motif. Sequence comparison showed that ISD1 belongs to the IS3 family. Isolation and analysis of the chromosomal copies, ISD1-A and ISD1-B, by PCR and sequencing indicated that these are not flanked by direct repeats. ISD1-A is inserted in a region of the chromosome containing the gapdh-pgk genes (encoding glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase). Active transposition to other loci in the genome was demonstrated, offering the potential of a new tool for gene cloning and mutagenesis. ISD1 is the first transposable element described for the sulfate reducers, a large and environmentally important group of bacteria. The distribution of ISD1 in genomes of sulfate-reducing bacteria is limited. A single copy is present in the genome of D. desulfuricans Norway.

[Study on the enantiomeric separation of adrenalines by capillary zone electrophoresis]

Capillary zone electrophoresis (CZE) has been used for the enantiomeric separation of the racemic isoprenaline, noradrenaline and adrenaline with bare fused silica capillary and employing beta-cyclodextrin(beta-CD) and beta-cyclodextrin derivatives as the chiral selectors. Both the complexion and enantiomeric resolution were influenced by the temperature, beta-CD type, CD concentration and pH of background electrolyte (BGE). The effects of the BGE types and concentrations on the enantiomeric separation were also investigated. The results showed that 2,6-di-O-carboxymethyl-beta-cyclodextrin (CM-beta-CD) has stronger recognition than that of beta-CD for the chiral separation of the basic drugs under study. The CD concentrations and pH of BGE have strong influence on the efficiency of chiral separation. The adsorption of the basic compound on the surface of bare fused silica capillary is a disadvantage to the chiral separation while the use of beta-CD as the chiral selector and the addition of an amphiphile, such as tetraethylammonium bromide (TEA+) or tetrabutylammonium bromide (TBA+) to the BGE could improve the resolution of the enantiomers due to the reduction of the adsorption of the basic compound on the silica surface by the strong electrostatic force between the positively charged amphiphile and the silica surface. It was also found that as CM-beta-CD was used as the chiral selector there was no influence on the chiral separation of the basic compound whether the amphiphile was added to BGE or not. Lower temperature was favorable to improve the efficiency of the chiral separation. CM-beta-CD gave a baseline enantiomeric separation for isoprenaline, while beta-CD, under the same experimental conditions, gave an incomplete chiral separation. Both CM-beta-CD and beta-CD could not give enantiomeric resolution for noradrenaline and adrenaline.

[Localization of ferritin in placental villous tissue and its role in the maternal-fetal iron transport]

OBJECTIVE

To investigate the localization and quantity of ferritin in placental villous tissue and its implications.

METHODS

The localization of ferritin in placental villous tissue at different gestation period was assayed by immunocytochemistry. The quantity of ferritin in placental villous tissue was determined with radioimmunoassay.

RESULTS

Ferritin was localized in all layers of the trophoblast, especially in the surface of the syncytiotrophoblast and basal membrane. The quantity of ferritin in placental villous tissue was increased with gestation progress and decreased in pregnant women with IDA.

CONCLUSIONS

Ferritin may be the important carrier of transplacental iron transport, and its receptor plays a crucial role in the course. The placental iron transport varied with gestation progress and iron nutritional status of the mother.

[Expression of ferritin receptor on placental microvillous membrane and its role in maternal-fetal iron transport]

OBJECTIVE

In order to investigate the expression of ferritin receptor (FnR) on human placental microvillous membrane in mid-pregnancy and its implication.

METHODS

Radioligand binding assay was used, with horse spleen 125I-apo-ferritin as radioligand.

RESULTS

The FnR expression in normal placental microvillous membrane in mid-pregnancy was (9.63 +/- 4.72) x 10(12) sites/mg pro, similar to that in normal placental of term delivery,and the dissociation constants (Kd) between them had also no significant difference: Competitive binding assay indicated that the receptor bound basic ferritin with higher affinity than acidic one.

CONCLUSIONS

The expression of FnR in mid-pregnancy almost come to mature level; The FnR on placenta might be involved in maternal-fetal iron transport, transfering iron from mother to fetal.

[Review of the development of capillary electrochromatography]

Capillary electrochromatography is a new micro-LC technique which combines the selectivity of HPLC and the high efficiency of HPCE. It utilizes EOF or EOF with pumped flow to drive mobile phase fluids through a stationary phase in a capillary column and permits the separations of charged and uncharged compounds. Capillary electrochromatography can be divided into three categories: packed-column electrochromatography, open-tubular electrochromatography and pressurized-flow electrochromatography. The paper surveys the recent development of the capillary electrochromatography.

[Three kinds of standing-materials for concha in reconstruction of ear]

In the reconstruction of the concha, standing support was necessary. From 1984 to 1996, 33 cases of aurical defects were admitted. Three standing-materials were chosen, and they included carved autogenous cartilage, heterogenous concha cartilage and steel wire work silicon-wires with silastic rubber tube. After expansion of the postauricular skin by tinsion expander, the standing-material was enveloped and total ear reconstruction or repair was performed. After followed up for average of 3.5 years, of the twenty-two cases, 16 had a satisfactory result, unsatisfied in 3 and failure in 3. It was concluded that the outcome of autogenous concha cartilage as a standing-material was good. The other two materials if used should be very carefully.

Growth factor-induced transcription via the serum response element is inhibited by cyclic adenosine 3',5'-monophosphate in MCF-7 breast cancer cells

The effect of increased intracellular cAMP on MCF-7 breast cancer cell growth was examined by treating cells with either forskolin, an activator of adenylate cyclase, or 8-[4-chlorophenylthio]-cAMP (8-CPT-cAMP), a cAMP analog. Compared to cells maintained in control medium, treatment with either 1 or 10 microM forskolin decreased cell growth by 17% and 68%, respectively, whereas treatment with 250 microM 8-CPT-cAMP decreased cell growth by 29%. To determine whether this effect of cAMP on cell growth was mediated by inhibition of the activity of extracellular signal-regulated kinases 1 and 2 (ERK1 and -2), two mitogen-activated protein kinases, the effect of cAMP on growth factor-induced ERK activity in MCF-7 cells was examined. Treatment with either insulin-like growth factor I (IGF-I) or epidermal growth factor (EGF) for 10 min stimulated a 4- to 8-fold increase in ERK1 and -2 activity. This effect of IGF-I and EGF was not inhibited by increased intracellular cAMP generated by pretreatment of the cells with 10 microM forskolin. Similarly, 10 microM forskolin had no effect on IGF-I- or EGF-induced ERK activity in cells treated with growth factor for 30 min. To determine whether cAMP inhibits other growth factor-mediated effects, its effect on the activity of the serum response element (SRE), a DNA promoter element whose activity is regulated by a variety of growth-promoting events, was examined. For these assays, MCF-7 cells were transiently transfected with pTK81-SRE-Luc, a luciferase fusion gene that contains the SRE cloned 5' to a minimal thymidine kinase promoter and the luciferase gene. Treatment with either IGF-I or EGF increased pTK81-SRE-Luc activity in a dose-dependent fashion. Pretreatment of cells with 10 microM forskolin decreased IGF-I- and EGF-stimulated luciferase activity by approximately 75%. An intermediate effect was observed using 1 microM forskolin. When intracellular cAMP levels were increased using 8-CPT-cAMP, similar results were obtained. SRE activity is dependent upon the activation by phosphorylation of a ternary complex factor; included among the ternary complex factors is Elk-1. When MCF-7 cells were cotransfected with a vector that expresses a Gal4/Elk-1 fusion protein and UAS-TK-Luc, a plasmid that contains two Gal4 DNA recognition sites cloned 5' to a thymidine kinase promoter and the luciferase gene, treatment with forskolin partially inhibited the activation of Elk-1 by IGF-I and EGF. These data demonstrate that in MCF-7 breast cancer cells, cAMP has no effect on IGF-I- or EGF-induced ERK activity, but it inhibits growth factor-induced transcription. Taken together with the effects of cAMP on IGF-I- and EGF-induced Elk-1 activation, these data suggest that the effect of cAMP on SRE activity occurs distal to ERK activation, possibly via inhibition of an ERK-independent pathway. Finally, these data indicate that the effect of increased intracellular cAMP on breast cancer growth may be mediated through inhibition of specific growth factor-induced effects, including gene transcription.

Deletion of two downstream genes alters expression of the hmc operon of Desulfovibrio vulgaris subsp. vulgaris Hildenborough

The hmc operon of Desulfovibrio vulgaris subsp. vulgaris Hildenborough consists of six genes (hmcA to hmcF) that encode structural components of the high-molecular-mass cytochrome redox protein complex (the Hmc complex). Two genes (rrf1 and rrf2) encoding regulatory proteins are present downstream of hmcF. Expression of the hmc operon, monitored by incubating protein blots with HmcA-specific or HmcF-specific antibodies, was found to be highest when hydrogen was the sole electron donor for sulfate reduction. Use of lactate or pyruvate as electron donor reduced expression of the hmc operon. A mutant with a deletion of the rrf1 and rrf2 genes was generated with the sacB mutagenesis method. This mutant overexpressed the hmc operon approximately threefold. It grew more rapidly than the wild type when hydrogen was used as the electron donor for sulfate reduction, but more slowly than the wild type when lactate was used. The results indicate that a physiological function of the Hmc complex is in electron flow from hydrogen to sulfate. At least one redox carrier is shared competitively by the hydrogen and lactate oxidation pathways in D. vulgaris.

[An analysis of acute leukemia cells TfR expression in children]

There are a lot of transferrin receptors on the acute leukemia cells. We used the method of "Receptor Radioligand Assay" to determine the numbers of TfR binding sites on leukemia cells from 20 child patients with acute lymphocyte leukemia (ALL) and 9 with acute myeloid leukemia (AML). The results showed the numbers of TfR binding sites of AML cells were higher than those of ALL cells, and the numbers of complete remission group were lower than those of dead or relapse group. This indicated there might be a relationship between the TfR expression and the prognosis.

Measurement of spin-lattice relaxation times of 13C in organic solids

A transient nuclear Overhauser effect (NOE) makes measurements of the 13C spin-lattice relaxation times in organic solids complicated. Extended Solomon equations are applied in order to describe 13C spin-lattice relaxation with 1H r.f. field irradiation. Spin-lattice relaxation under r.f. irradiation is shown to be generally a triple-exponential process, but it can be reduced to be single-exponential under stronger r.f. field irradiation as well as in the absence of 1H initial magnetizations. Based on numerical calculations, the difference between spin-lattice relaxation curves obeying T1C < T1H and those obeying T1C > T1H is clearly indicated. The methyl group resonances in solid-state L-valine are examined, and the experimental results agree well with the theoretical results.

Curious Consequences of Strong Coupling in NMR Experiments Involving Selective Pulses

This study is concerned with the effects of applying selective pulses to systems with strong second-order scalar couplings in isotropic phase, where different transitions (rs) are associated with different transition matrix elements F+(rs). Two unusual features can be distinguished: the nutation angle ("flip angle") depends on the matrix element of the irradiated transition (rs), and, in contrast to the behavior of an isolated spin-(1/2) system, the norm of the three single-transition operators [I(rs)x, I(rs)y, I(rs)z] associated with the fictitious spin-(1/2) space of the irradiated transition (rs) is generally not conserved. It is necessary to consider the single-transition operators [I(rp)x, I(rp)y, I(rp)z] and [I(sq)x, I(sq)y, I(sq)z] associated with all connected transitions (rp) and (sq) that share a common energy level r or s with the irradiated transition (rs). If the pulse applied to the (rs) transition is sufficiently selective, the transverse components I(rp)x, I(rp)y, I(sq)x, and I(sq)y, can be neglected, since their expectation values remain equal to zero after application of a selective pulse to the (rs) transition, but the longitudinal components I(rp)z and I(sq)z acquire nonvanishing expectation values. When the selective pulse affects several transitions simultaneously, the response varies from one transition to another, depending on the matrix elements and the connectivities. These effects manifest themselves in unusual amplitudes and phases of signals excited by selective pulses, in particular in selective two-dimensional correlation spectra.

Divergent double chirp pulses for refocusing quadrupolar interactions

To excite and refocus single quantum coherences in a three-level system with a quadrupolar interaction, it is possible to use frequency-modulated pulses with two diverging frequency components that are swept simultaneously through the two single-quantum transitions. This is achieved by time-dependent amplitude-modulation of the carrier frequency, so as to generate two sidebands with frequencies that are diverging (or converging) symmetrically with respect to the carrier frequency. Simulations and experiments show that such modulated pulses can be used to refocus single quantum coherences to form quadrupole echoes, using much weaker RF amplitudes than in conventional echo sequences. To visualize the evolution of the coherences in a three-level system, a graphical representation of the density operator components is proposed.

NMR of residual protons in partly deuterated anisotropic materials with phase-alternated decoupling of deuterium spins

A new method is presented for decoupling spins with S = 1 like deuterium in anisotropic media while observing other spins such as residual protons in partly deuterated samples. The carrier frequency of a weak radiofrequency (RF) field is applied near the center of the doublet arising from the quadrupolar interaction of the S = 1 spins. The phase of the RF field is periodically reversed with intervals matching the reciprocal of the magnitude of the quadrupolar splitting. It is shown by theory and experiment that, even when the irradiating field is quite weak, the efficiency of this phase-alternated decoupling scheme is much better than for simple continuous-wave irradiation at the center of the doublet, an established technique which is usually referred to as double quantum decoupling. The phase-alternated experiment makes it possible to decouple large quadrupolar interactions with a weak RF field. A theoretical analysis and numerical simulations are presented to demonstrate the decoupling performance. Proton spectra of partly deuterated dibromobutane in a liquid crystalline solvent have been recorded to illustrate the efficiency of phase-alternated deuterium decoupling.

Macrophage inflammatory protein-1 beta: a C-C chemokine in osteoarthritis

The aim of this study was to determine whether the cytokine macrophage inflammatory protein-1 beta (MIP-1 beta) is present and functionally active in the arthritic joint. We used immunoassays and bioassays to assess the presence and function of MIP-1 beta using samples obtained from 62 arthritic patients. MIP-1 beta levels were increased in synovial fluids (SFs) from patients with osteoarthritis (OA) (18.0 +/- 8.9 ng/ml) (SD) compared to patients with rheumatoid arthritis (RA) 6.1 +/- 2.9 ng/ml) or other forms of arthritis (10.4 +/- 7.0 ng/ml) (P < 0.05). Levels of OA SF MIP-1 beta were significantly greater than OA or normal serum levels of MIP-1 beta. Anti-MIP-1 beta neutralized 28% of the chemotactic activity for monocytes found in OA SFs. Isolated OA synovial tissue fibroblasts did not constitutively produce MIP-1 beta but could be induced to express this chemokine upon exposure to tumor necrosis factor-alpha, interleukin-1 beta, or lipopolysaccharide. Synovial tissue immunohistochemical staining revealed that the main immunopositive cells in OA were the lining cells as well as vascular smooth muscle and endothelial cells. A minority of macrophages were immunopositive as well. In this study, we identify MIP-1 beta as a unique cytokine increased in OA compared to RA SF. We conclude that MIP-1 beta may play a role in the ingress of monocytes into the OA joint.

Increased synovial expression of transforming growth factor (TGF)-beta receptor endoglin and TGF-beta 1 in rheumatoid arthritis: possible interactions in the pathogenesis of the disease

The ingress of inflammatory cells into the rheumatoid (RA) synovial tissue (ST) plays a role in the pathogenesis of this disease. Transforming growth factor beta (TGF-beta) may play a role in this process. We have investigated the distribution of endoglin, a newly described receptor for TGF-beta 1 and -beta 3, in RA compared to osteoarthritis (OA) or normal ST. Immunohistochemical analysis was carried out using an anti-TGF-beta 1 monoclonal antibody (mAb) as well as 10 mAbs raised against various epitopes of endoglin. This study was performed on ST from 10 patients with RA, 10 with OA, and 4 normal individuals. TGF-beta 1 expression was significantly up-regulated on RA compared to OA and normal ST lining cells, interstitial macrophages, and endothelial cells (P < 0.05). All anti-endoglin mAbs uniformly reacted with endothelial cells in RA, OA, and normal STs. However, 3 out of 10 anti-endoglin mAbs reacted with significantly more RA versus normal ST lining cells (P < 0.05), as well as RA compared to OA and normal macrophages (P < 0.05). There was a positive correlation between TGF-beta 1 and endoglin reactivity on the synovial lining layer and subsynovial macrophages (P < 0.05). These results indicate that TGF-beta 1 and certain epitopes of endoglin, a TGF-beta 1 and -beta 3 receptor, are up-regulated on myeloid elements in RA compared to normal ST. Endoglin is also present on ST endothelia, and its expression may also be increased on OA compared to normal ST lining cells. These findings implicate endoglin in the pathogenesis of RA.

Increased synovial expression of the adhesion molecules CD66a, CD66b, and CD31 in rheumatoid and osteoarthritis

Leukocyte-endothelial interaction mediated by adhesion molecules may play a role in the ingress of inflammatory cells into the rheumatoid (RA) synovial tissue (ST). A number of these molecules have been shown to be up-regulated in the inflamed compared to normal ST. We studied the distribution of two members of the CD66 carcinoembryonic antigen adhesion molecule family, as well as that of CD31, an antigen structurally related to CD66, on various cell types in the RA compared to osteoarthritic (OA) and normal ST. Immunoperoxidase histochemistry was carried out using monoclonal antibodies to CD66a, CD66b, and CD31. This study was performed on ST from 10 patients with RA, 10 with OA, and 4 normal individuals. CD66a, and CD66b were expressed on RA and OA ST myeloid cells but not on normal ST lining cells and interstitial macrophages, suggesting that these antigens may be specific markers of diseased compared to normal ST macrophages (P < 0.05). CD31 was present on more RA and OA than on normal ST macrophages. Also, CD31 was present on most RA, OA, and normal ST endothelial cells. Our results indicate that the expression of CD66a, CD66b, and CD31, members of the immunoglobulin superfamily of adhesion receptors, is up-regulated on cells of myeloid origin in the inflamed compared to normal ST. These results suggest that the CD66 antigens and CD31 may be involved in the adhesive events in the inflamed synovium.

[A 3-year follow-up study of 50 children with acute lymphoblastic leukemia]

Fifty children with acute lymphoblastic leukemia were followed up for an average period of 3 3/12 years. The results showed that 19 (38%) cases were given up after diagnosis. Eight patients only received treatment irregularly for 1 year; among them, 2 discontinued therapy by themselves for 2-3 years and survived free of events, and 6 were lost, Twenty-three received treatment regularly; among them, 3 died of infection, 11 were in continuously complete remission and 9 experienced relapse. The total disease-free survival rate for mean 3 3/12 years is 42% (13/31), exclusive of the 19 given up cases. Statistical analysis indicates a higher relapse rate in those cases with lower initial glucocorticoid receptors (GCR) of peripheral blood lymphocytes.

[Effect of environmental temperature, cryopreservation and aging on Plasmodium vivax sporozoites developing into exoerythrocytic stages]

After Anopheles stephensi mosquitoes with salivary infection of Plasmodium vivax were put in environments with temperatures of 30 +/- 1 degrees C, 26 +/- 1 degrees C or 13 +/- 1 degrees C for 5 d, their glands were aseptically dissected and sporozoites were collected and inoculated into HepG2-A16 cell monolayers. Seven days post-inoculation the cultured materials were harvested and the exoerythrocytic schizonts and hypnozoites were observed under the microscope by using immunoperoxidase staining technique. The results showed that the sporozoite developing rate of 30 +/- 1 degrees C group and 13 +/- 1 degrees C group was significantly lower than that of 26 +/- 1 degrees C group (0.33%, 0.35% and 0.75% respectively). The proportion of hypnozoites in the total number of EE forms was the highest in the low temperature group (62.5%) compared with 26 +/- 1 degrees C and 30 +/- 1 degrees C group (40.1% and 42.7% respectively). Suggesting that the low environmental temperature first affected the viability of tachysporozoites or the phenotype of sporozoites and thus resulted in heightened hypnozoite rate. This is parallel to the epidemiological data that in the regions of high latitute vivax malaria with long incubation period was more frequently observed. When the sporozoites within the body of mosquito were cryopreserved at -70 degrees C or in liquid nitrogen for 24 h or 5 d respectively, the proportion of hypnozoite increased 87.4% and 82.4%, respectively. However, cryopreservation did not inactivate all of the tachysporozoites, indicating that the resistance to ultralow temperature in bradysporozoite was much greater than that in tachysporozoites. Aging of sporozoites decreased their developing rate and the exoerythrocytic (EE) schizonts were found to grow sluggishly and asynchronously, indicating that the size of EE schizont and the age of sporozoites are in negative correlation. Meantime, proportion of the hyponozoite decreased significantly.

[Observation on hypnozoite of different isolates of Plasmodium vivax in cultured materials]

The hypnozoites of different isolates of P. vivax from Shenzhen and Shixin, Guangdong Province, Changsha, Hunan Province and Yincheng, Hubei Province of China in cultured materials were observed employing immunoperoxidase staining method. The percentages of hypnozoites among exoerythrocytic stages were 40.1, 43.5, 50.6 and 57.1%, respectively, indicating that the percentage of hypnozoites and the latitude are in positive correlation. The equation is y = -6.68 + 2.05x. When the difference in latitude of Plasmodium vivax isolate source was more than 5 degrees, a significant difference in the percentage of hypnozoites in various geographic isolates was found. However, the average diameters of hypnozoites and schizonts among various geographic isolates showed no significant difference. The results showed that in the regions north to the Yangtze River, the proportion of hypnozoite in the liver stage of P. vivax was larger than those in the southern China, being consistent with the clinical manifestations.

Hybrid rice (Oryza sativa L.): identification and parentage determination by RAPD fingerprinting

DNA from three families of rice plants selected in Northern China (each comprising the male sterile, the restorer, the hybrid F1 and the maintainer lines) has been extracted and amplified by PCR with different random DNA primers (RAPD analysis). Then, DNA has been analysed by agarose gel electrophoresis and DNA bands scored as present or absent. The generated matrices are reproducible and amenable for identification of each single plant line. Thus, RAPD fingerprinting of the inbred parental lines and of the resulting hybrid is proposed as a convenient tool for the identification, protection and parentage determination of plant hybrids. Furthermore, by offering a molecular tool to verify the degree of dissimilarity between the parental lines, the RAPD analysis may also be used to search for new parental combinations.