A novel DNA vaccine based on ubiquitin-proteasome pathway targeting 'self'-antigens expressed in melanoma/melanocyte

Cancer vaccine that targets 'self'-antigens expressed at high levels in tumor cells is a potentially useful immunotherapy, but immunological tolerance often defeats this strategy. Here, we describe the use of a naked DNA vaccine encoding a self tumor antigen, tyrosinase-related protein 2, to whose N-terminus ubiquitin is fused in a 'nonremovable' fashion. Unlike conventional DNA vaccines, this vaccine broke the tolerance and induced protective immunity to melanoma in C57BL/6 mice, as evaluated by tumor growth, survival rate and lung metastasis. The protective immunity was cancelled in the proteasome activator PA28alpha/beta knockout mice. Moreover, this vaccination exhibited therapeutic effects on melanoma implanted before vaccination. Our findings provide evidence for the first time that naked DNA vaccines encoding a ubiquitin-fused self-antigen preferentially induce the main effector CD8+ T cells through efficient proteolysis mediated by the ubiquitin-proteasome pathway, and lead the way to strategies aimed at targeting tissue differentiation antigens expressed by tumors.

Genetic evidence of local adaptation of wheat yellow rust (Puccinia striiformis f. sp. tritici) within France

Puccinia striiformis f. sp. tritici (PST), a clonal basidiomycete causing yellow rust disease on wheat, has a long record of 'overcoming' cultivar resistance introduced by breeders. Despite the long dispersal capacity of its spores, the French population of PST presents a strong geographical structure, with the presence of a specific pathotype (array of avirulence genes) at high frequencies in the south of France. The genetic diversity underlying this differentiation was analysed by microsatellite and AFLP markers. A total of 213 French isolates belonging to 10 pathotypes collected over a 15-year period were investigated. For each of the 12 microsatellites used, polymorphism resulted from a unique allelic variant associated to the south-specific pathotype. This pathotype was characterized by 40 specific markers over the total of 63 polymorphins detected using 15 AFLP primer combinations. Phylogeographical analysis indicated a strictly clonal structure of the population, and a strong genomic divergence between the northern population and a south-specific clone. Both virulence and molecular data show that the northern French population belongs to the northwestern European population, whereas the southern clone is most likely related to a Mediterranean population, the two subpopulations resulting from the ancient divergence of two clonal lineages. While the virulence complexity in the northern population may be explained by the successive introduction of corresponding resistance genes in cultivars, the maintenance of a simple virulence type in southern France, despite gene flow between the two populations, may be explained in terms of host cultivars repartition and local adaptation to specific host or climatic conditions.

Chinese medicinal herbs for acute bronchitis

BACKGROUND

Acute bronchitis is one of the most common diagnoses made by primary-care physicians. It is traditionally treated with antibiotics, (although the evidence for their effectiveness is weak and modest at best), and other even less effective treatments. Chinese medicinal herbs have been also used as treatment.

OBJECTIVES

This review aims to summarise the existing evidence on the comparative effectiveness and safety of Chinese medicinal herbs for treating uncomplicated acute bronchitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2005), which includes the Cochrane Acute Respiratory Infections Group's specialised register; The Chinese Cochrane Centre's Controlled Trials Register (up to December 2004); MEDLINE (1966 to March Week 1, 2005); EMBASE (1988 to December 2004); and the Chinese Biomedical Database (CBM) (1980 to December 2004).

SELECTION CRITERIA

Randomised controlled trials comparing Chinese medicinal herbs with placebo, antibiotics or other Western medicines for the treatment of uncomplicated acute bronchitis.

DATA COLLECTION AND ANALYSIS

At least two authors extracted data and assessed trial quality.

MAIN RESULTS

Four trials reported the time to improvement of cough, fever, and rales associated with bronchitis and showed that patients treated with Chinese herbs had a shorter duration of signs and symptoms. Two trials reported the proportion of patients with improved signs and symptoms at follow up and showed that Chinese herbs were beneficial in terms of relief of signs and symptoms. Thirteen trials analysed the data on physician global assessment of improvement at follow up. Nine of thirteen trials showed that Chinese herbs were superior to routine treatment and the other four trials showed a similar effect to routine treatment. In general, Chinese herbs appeared beneficial. Only one trial reported on adverse effects during treatment.

AUTHORS' CONCLUSIONS

There is insufficient quality data to recommend the routine use of Chinese herbs for acute bronchitis. The benefit found in this systematic review could be due to publication bias and study-design limitations of the individual studies. In addition, the safety of Chinese herbs is unknown due to the lack of toxicological evidence on these Chinese herbs, though adverse events are rarely reported. Chinese herbs should be used carefully.

beta2-Adrenergic receptor gene variations associated with stage-2 hypertension in northern Han Chinese

The aim of this study was to investigate the association between polymorphisms in the beta(2)-adrenergic receptor gene (ADRB2) (-47C/T, Arg16/Gly, Gln27/Glu) and stage-2 hypertension in northern Han Chinese. We recruited 503 individuals with stage-2 hypertension and 504 age-, gender-, and area-matched controls from the International Collaborative Study of Cardiovascular Disease in Asia. Genotyping was performed using PCR-RFLP. Logistic regression analyses revealed that carriers of the Gly16 allele had a significantly higher odds ratio (OR) for hypertension, while carriers of the Glu27 allele had a significantly lower OR. In multivariate linear regression analyses, the Arg16/Gly and Gln27/Glu genotypes were significantly associated with systolic blood pressure level (p = 0.004 and p < 0.001, respectively). In haplotype analyses, we found the frequency of haplotypes composed of the Gly16 and Gln27 alleles was significantly higher, whereas the frequency of haplotypes composed of the Arg16 and Glu27 alleles was significantly lower, in hypertensives compared to their controls (both p = 0.001). These results indicate that the Gly16 and Gln27 alleles of the ADRB2 gene confer an increased risk for stage-2 hypertension in this northern Han Chinese population.

Chinese medicinal herbs for influenza

BACKGROUND

Influenza is an acute respiratory communicable disease which can cause high morbidity and mortality in an epidemic. Traditional Chinese medicinal herbs following a particular theory may be a potential medicine of choice.

OBJECTIVES

The objective of this review was to assess the therapeutic effect and adverse reaction of Traditional Chinese medicinal herbs in treating uncomplicated influenza.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2004); MEDLINE (January 1966 to October 2004); EMBASE (January 1988 to October 2004); CBM (Chinese Biomedical Database) (January 1980 to December 2003); and the Chinese Cochrane Center's Controlled Trials Register (up to December 2003). We also searched Current Controlled Trials (www.controlled-trials.com) and the National Research Register (http://www.update-software.com/National/) for ongoing trials and reference lists of articles. We wrote to researchers in the field, or authors of studies evaluated in the review for more information.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing traditional Chinese medicinal herbs with placebo, or various other Chinese medicinal herbs, or with other current regimes normally used in care or comparing drugs with herbal preparations to simple drugs in treating defined uncomplicated influenza patients.

DATA COLLECTION AND ANALYSIS

At least two reviewers extracted data and assessed trial quality.

MAIN RESULTS

Eleven studies with the number of participants ranged from 52 to 479. In total 2,088 participants were included in the review. As the interventions of the included studies were different from each other and most of the studies were of low quality, we did not perform a summary meta-analysis. Some of the studies showed positive results favouring Traditional Chinese medicinal herb treatment compared to antiviral or antipyretic-analgesic drugs or the combination of them. Only three studies mentioned adverse reactions but no detailed data were acquired in the included studies. Eleven studies with the number of participants ranged from 52 to 479, 2,088 in total were included. As the interventions of the included studies were different from each other and most of the studies were of low quality, we failed to perform a summary meta-analysis. Some of the studies showed positive results favouring Traditional Chinese medicinal herb treatment compared to antiviral or antipyretic-analgesic drugs or the combination of them. Only three studies mentioned adverse reactions but no detailed data was acquired in the included studies.

AUTHORS' CONCLUSIONS

The small number of included studies and participants, as well as the low quality of most studies, made the evidence far from conclusive for clinical decision making, although traditional Chinese medicinal herbs as a whole seem to be comparatively or more effective compared to different chemical drugs. A certain herbal preparation could not be recommended for there was not enough evidence. More high quality randomised controlled trials (RCTs) with similar interventions are required to strengthen the evidence for the efficacy and safety of certain herbal preparation.

Analysis of immobilizedL-cysteine on polymers

Recently, we reported that L-cysteine attached to polymeric biomaterials, without prior nitrosation, enhances the hemocompatibility of biomaterials via exploiting endogenous nitric oxide (NO). As part of the polymer optimization process to further enhance platelet inhibition, a kinetic model is being developed to predict the release rate of NO. A key model parameter is the immobilized concentration of L-cysteine. This article demonstrates how several chemiluminescence-based assays, previously utilized for measuring thiols in solution, were successfully adapted to quantify immobilized L-cysteine. The assays showed that the immobilized L-cysteine on the modified PET sample is within the range of 4.1 to 6.5 nmol/cm(2). An advantage of using the more successful chemiluminescence-based assay is that it can accurately measure molar concentrations of any thiol-containing compound with a detection limit in the pmol range. The major disadvantage is that L-cysteine must first be broken off of the polymer and released into solution prior to measurement, therefore leaving the sample unable to be reused. Other thiol-measuring techniques, such as fluorescence microscopy and X-ray photoelectron spectroscopy (XPS), were used to provide qualitative and semiquantitative analysis to substantiate the polymer development.

Thermodynamic model of electric-field-induced pattern formation in binary dielectric fluids

An electric-field-induced phase transition and pattern formation in a binary dielectric fluid layer are studied using a coarse-grained free-energy functional. The electrostatic part of the free energy is a nonlinear functional of the dielectric function, which depends in turn on the local colloidal concentration. We determine the phase coexistence curve and find that beyond a critical electric field the system phase separates. Accompanying the phase separation are patterns similar to those observed in a spinodal decomposition of an ordinary binary fluid. The temporal evolution of the phase separating patterns are discussed both analytically and numerically by integrating a Cahn-Hilliard type of equation.

Partitioning of model toxins to hydrophobically terminated DAB dendrimers

Dendrimers are attractive in biological and biomedical applications due to the similarity in their molecular size to biologically relevant molecules and the large number of chain ends available functionalization. In the current work, we examined the potential of diamino butane (DAB) dendrimers functionalized with long alkyl chains as partitioning agents for hydrophobic toxins for use as a prefiltering stage in a bioartiticial liver. DAB dendrimers of various generations that had been previously fully modified with palmitoyl chloride were obtained. A study of the kinetics of partitioning of acetylsalicylic acid (ASA) suggested that while significant toxin removal occurred in 30 s, although a slight time dependent increase in removal was noted up to 60 minutes. The partitioning of 6 hydrophobic toxins from aqueous solution to the modified dendrimers in 30 minutes was examined. The results demonstrated that a number of factors, including the pKa of the toxin, its octanol water partitioning coefficient and molecular size contributed to the level of toxin removal. Toxin removal on a molar basis increased with increasing dendrimer generation for all toxins, with the modified G5 dendrimers partitioning 50-100 toxin molecules in most cases. Dendrimer modification with C4 alkyl chains rather than Cl5 chains significantly decreased toxin removal, although chains longer than C10 seemed to partition equal amounts of toxins. The results of the study demonstrate that water-soluble dendrimers modified with hydrophobic end groups may be useful for the removal of toxins from the blood in a prereaction step for a bioartificial liver, but that a better understanding of the molecular mechanisms of removal may be necessary before it is possible to predict the levels of toxin removal.

Prevalence of diabetes and impaired fasting glucose in the Chinese adult population: International Collaborative Study of Cardiovascular Disease in Asia (InterASIA)

AIMS/HYPOTHESIS

To estimate the prevalence of diagnosed and undiagnosed diabetes and impaired fasting glucose in the general adult population of China.

METHODS

The International Collaborative Study of Cardiovascular Disease in ASIA, conducted from 2000 to 2001, included a nationally representative sample of 15 540 adults, aged 35 to 74 years. An overnight fasting blood specimen was collected to measure serum glucose and information on history of diabetes and use of hypoglycaemic medications was obtained by a standard questionnaire. Undiagnosed diabetes (fasting glucose > or =7.0 mmol/l) and impaired fasting glucose (6.1-6.9 mmol/l) were defined using the American Diabetes Association criteria.

RESULTS

Prevalence of self-reported diagnosed diabetes, undiagnosed diabetes, and impaired fasting glucose in Chinese adults were 1.3%, 4.2%, and 7.3%, respectively. Overall, 5.2% or 12.7 million men and 5.8% or 13.3 million women in China aged 35 to 74 years had diabetes (self-reported diagnosis plus undiagnosed diabetes). The age-standardized prevalence of diabetes was higher in residents of northern compared to southern China (7.4% vs 5.4%, p<0.001) and in those living in urban compared to rural areas (7.8% vs 5.1%, p<0.001).

CONCLUSIONS/INTERPRETATION

Our results show that the prevalence of diabetes in the adult population in China is much higher than previously reported. Three out of every four diabetes patients are undiagnosed, indicative of a lack of population-based screening programmmes and a relatively rapid and recent increase in incidence of diabetes. These results indicate that diabetes has become a major public health problem in China and underscore the need for national strategies aimed at prevention and treatment of diabetes.

Novel dendrimer based polyurethanes for PEO incorporation

A series of segmented polyurethanes based on methylene diisocyanate/poly (tetramethylene oxide) and chain extended with either ethylene diamine or butane diol in combination with a generation 2 polypropylenimine octaamine dendrimer were synthesized. For polymer synthesis, the dendrimers were protected with either t-boc or Fmoc groups and were incorporated into the polyurethane microstructure to permit further functionalization with biologically active groups. Following deprotection, the dendrimers were reacted with succinimidyl propionate polyethylene oxide (SPA-PEO) to improve the protein resistance of the polymers and to examine the potential of this technique for polymer functionalization. Different synthesis techniques were examined to optimize the incorporation of the PEO into the polymer microstructure. Incorporation of the dendrimers and the PEO were confirmed by NMR and FTIR. Gel permeation chromatography was used to examine the molecular weights of the various polyurethanes. The dendrimer incorporated polymers had significantly lower molecular weights than the ED or BDO chain extended controls, likely due to lower reactivity of the dendrimers as a result of steric factors. Following PEO reaction, the molecular weights of the resultant polymers were consistent with the levels of PEO incorporation noted by comparison of peak intensities in the NMR spectra. Due to the highly hydrophilic nature of the PEO, some migration to the polymer surface was expected. Water contact angles and XPS, used to characterize the surfaces, suggest that there was some PEO enrichment at the surface of the polymers. Adsorption of radiolabeled fibrinogen to the polymer surfaces was decreased by a factor of approximately 40% in some of the PEO incorporated polymers. There were also differences in the patterns of plasma protein adsorption on the various surfaces as evaluated by SDS PAGE and immunoblotting. Therefore, the use of dendrimers in biomaterials for incorporation of a large number of functional groups seems to be promising.

[Long-term follow-up study on Hunan aqueous drainage implantation for refractory glaucoma]

One hundred and three cases(106 eyes) of refractory glaucoma underwent Hunan aqueous drainage (HAD) implantation from July 1993 to January 1998. The mean period of postoperative follow-up was 32.8 months. The intraocular pressure(IOP) was decreased from preoperative 6.6 +/- 1.8 kPa to postoperative 2.2 +/- 1.4 kPa at the 1st year after surgery. The success rates were 83.8% at the 1st year, 80.4% at the 2nd year, 77.1% at the 3rd year, 71.0% at the 4th year, and 64.3% at the 5th year using Kaplan-Meier lifetable analysis. The neovascular glaucoma had lower success rate. The success rate in 38 patients who were used adjunctively with mitomycin C in the operation was 89.5% at the 1st year. The common complications included early continuous flat anterior chamber, local choroidal detachment, increased IOP, and so on. This study suggests that HAD implantation is an effective method in the treatment of refractory glaucoma in spite of its complications.

In Situ Sol–Gel Preparation of Polysaccharide/Titanium Oxide Hybrid Colloids and Their Electrorheological Effect

A new type of organic/inorganic hybrid colloid, made of modified carboxylmethyl starch (CMS) and titanium oxide (TiO(2)), was synthesized by an in situ sol-gel technique. IR spectra analysis shows strong a interaction of functional groups between two components, whose dispersion is almost at the molecular level. Due to the highly active surfaces hybrid particles and their characteristic dielectric behavior in accordance with the previous theoretic calculation, the suspensions of hybrids in silicone oil display a remarkable ER effect. The static yield stress can be above 20 kPa (shear rate 5 S(-1)) under a direct current field of 4 kV/mm at room temperature, much higher than that of simple blends of starch and titanium dioxide. In the meanwhile, the temperature dependence and sedimentation stability were optimized. Based on existing experimental results, we propose that dielectric properties and surface (interface) activity are two necessary conditions fulfilling the requirement of high ER activity. The combination of both factors may effectively reduce the activation energy needed for ERF restructuring.

Logic gates and computation from assembled nanowire building blocks

Miniaturization in electronics through improvements in established "top-down" fabrication techniques is approaching the point where fundamental issues are expected to limit the dramatic increases in computing seen over the past several decades. Here we report a "bottom-up" approach in which functional device elements and element arrays have been assembled from solution through the use of electronically well-defined semiconductor nanowire building blocks. We show that crossed nanowire p-n junctions and junction arrays can be assembled in over 95% yield with controllable electrical characteristics, and in addition, that these junctions can be used to create integrated nanoscale field-effect transistor arrays with nanowires as both the conducting channel and gate electrode. Nanowire junction arrays have been configured as key OR, AND, and NOR logic-gate structures with substantial gain and have been used to implement basic computation.

Highly polarized photoluminescence and photodetection from single indium phosphide nanowires

We have characterized the fundamental photoluminescence (PL) properties of individual, isolated indium phosphide (InP) nanowires to define their potential for optoelectronics. Polarization-sensitive measurements reveal a striking anisotropy in the PL intensity recorded parallel and perpendicular to the long axis of a nanowire. The order-of-magnitude polarization anisotropy was quantitatively explained in terms of the large dielectric contrast between these free-standing nanowires and surrounding environment, as opposed to quantum confinement effects. This intrinsic anisotropy was used to create polarization-sensitive nanoscale photodetectors that may prove useful in integrated photonic circuits, optical switches and interconnects, near-field imaging, and high-resolution detectors.

Effect of potassium supplementation on blood pressure in Chinese: a randomized, placebo-controlled trial

OBJECTIVE

To examine the effect of potassium supplementation on blood pressure (BP) in a Chinese population who consume a habitual high sodium and low potassium diet.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Community sample from Beijing, China.

PARTICIPANTS

A total of 150 men and women aged 35-64 years with an initial systolic BP 130-159 mmHg and/or diastolic BP 80-94 mmHg.

INTERVENTIONS

Participants were randomly assigned to take 60 mmol potassium chloride supplement or placebo for 12 weeks.

MAIN OUTCOME MEASURE(S)

BP measurements were obtained at baseline, and at 6 weeks and 12 weeks during the trial, using random-zero sphygmomanometers.

RESULTS

The average baseline urinary excretion of sodium and potassium was 182 mmol/24 h and 36 mmol/24 h. Baseline BP and other measured variables were similar between the potassium supplementation and placebo groups. In the active compared to the placebo treatment group, the urinary excretion of potassium was significantly increased by 20.6 mmol/24 h (P< 0.001) during 12 weeks of intervention. Compared to placebo, active treatment was associated with a significant reduction in systolic BP (-5.00 mmHg, 95% CI: -2.13 to -7.88 mmHg, P < 0.001) but not diastolic BP (-0.63 mmHg, 95% CI: -2.49 to1.23 mmHg, P = 0.51) during 12-week intervention.

CONCLUSION

These data indicate that moderate potassium supplementation resulted in a substantial reduction in systolic BP. Our findings suggest that increased potassium intake may play an important role in the prevention and treatment of hypertension in China.

[The psychological effect of clinical examination on women with tubal infertility]

OBJECTIVE

To comprehend the psychological effects in the course of diagnosis and treatment of infertility on the sexuality, emotional feeling and marriage of women with tubal infertility.

METHODS

The study involved 180 hospitalized patients who were awaiting tube operation from May to September in the year 2000. A survey was made by using questionnaire about sexuality, emotional feeling and marriage after infertility examinations.

RESULTS

The sexual intercourse frequency of 46.2% infertile women decreased and no influences on sexual living satisfaction were confirmed during basal body temperature (BBT) examination. 92.3% to 93.2% of the infertile women were sad after hysterosalpingography(HSG) and laparoscopy. 78.9% of them felt remorse when the result of semen examination was normal. 56.6% of them would choose in vitro fertilization and embryo transfer(IVF-ET); 38.9% of the infertile couples' wedlock would not be stable and 10.5% of them would be divorced in the case of continuing infertility 2 years after tube operation.

CONCLUSION

Sexual intercourse in almost half of the infertile couples decreased during BBT examination. Most infertile women became sad when they were informed of the abnormal results of HSG and laparoscopy and the normal results of semen analysis.

Crystal structures of the maltodextrin/maltose-binding protein complexed with reduced oligosaccharides: flexibility of tertiary structure and ligand binding

The structure of the maltodextrin or maltose-binding protein, an initial receptor for bacterial ABC-type active transport and chemotaxis, consists of two globular domains that are separated by a groove wherein the ligand is bound and enclosed by an inter-domain rotation. Here, we report the determination of the crystal structures of the protein complexed with reduced maltooligosaccharides (maltotriitol and maltotetraitol) in both the "closed" and "open" forms. Although these modified sugars bind to the receptor, they are not transported by the wild-type transporter. In the closed structures, the reduced sugars are buried in the groove and bound by both domains, one domain mainly by hydrogen-bonding interactions and the other domain primarily by non-polar interactions with aromatic side-chains. In the open structures, which abrogate both cellular activities of active transport and chemotaxis because of the large separation between the two domains, the sugars are bound almost exclusively to the domain rich in aromatic residues. The binding site for the open chain glucitol residue extends to a subsite that is distinct from those for the glucose residues that were uncovered in prior structural studies of the binding of active linear maltooligosaccharides. Occupation of this subsite may also account for the inability of the reduced oligosaccharides to be transported. The structures reported here, combined with those previously determined for several other complexes with active oligosaccharides in the closed form and with cyclodextrin in the open form, revealed at least four distinct modes of ligand binding but with only one being functionally active. This versatility reflects the flexibility of the protein, from very large motions of interdomain rotation to more localized side-chain conformational changes, and adaptation by the oligosaccharides as well.

Directed assembly of one-dimensional nanostructures into functional networks

One-dimensional nanostructures, such as nanowires and nanotubes, represent the smallest dimension for efficient transport of electrons and excitons and thus are ideal building blocks for hierarchical assembly of functional nanoscale electronic and photonic structures. We report an approach for the hierarchical assembly of one-dimensional nanostructures into well-defined functional networks. We show that nanowires can be assembled into parallel arrays with control of the average separation and, by combining fluidic alignment with surface-patterning techniques, that it is also possible to control periodicity. In addition, complex crossed nanowire arrays can be prepared with layer-by-layer assembly with different flow directions for sequential steps. Transport studies show that the crossed nanowire arrays form electrically conducting networks, with individually addressable device function at each cross point.

Indium phosphide nanowires as building blocks for nanoscale electronic and optoelectronic devices

Nanowires and nanotubes carry charge and excitons efficiently, and are therefore potentially ideal building blocks for nanoscale electronics and optoelectronics. Carbon nanotubes have already been exploited in devices such as field-effect and single-electron transistors, but the practical utility of nanotube components for building electronic circuits is limited, as it is not yet possible to selectively grow semiconducting or metallic nanotubes. Here we report the assembly of functional nanoscale devices from indium phosphide nanowires, the electrical properties of which are controlled by selective doping. Gate-voltage-dependent transport measurements demonstrate that the nanowires can be predictably synthesized as either n- or p-type. These doped nanowires function as nanoscale field-effect transistors, and can be assembled into crossed-wire p-n junctions that exhibit rectifying behaviour. Significantly, the p-n junctions emit light strongly and are perhaps the smallest light-emitting diodes that have yet been made. Finally, we show that electric-field-directed assembly can be used to create highly integrated device arrays from nanowire building blocks.

[Immortalization of the rabbit mandibular condylar chondrocyte with SV40]

OBJECTIVE

To establish an immortalized cell line of the mandibular condylar chondrocyte (MCC).

METHODS

Reconstructed retroviral vector pLN/SV40 containing the large T antigen and neomycin-resistance genes were transfected into the packaging cells PA317 using lipofectin transfection method. Then the primarily cultured cells derived from mandibular condylar chondrocytes(MCCs) of New Zealand rabbits were infected with the positive retrovirus medium and monoclone was selected with G418. Specific primer of large T antigen was designed and PCR was used to detect the integrating of large T antigen gene. The positive cell clones were subcultured and their growth characteristics were compared with untransfected cells.

RESULTS

10 cell clones of the transduced cells showed the positive gene fragment of 1,196 bp, and 5 of them had been further subcultured for more than 30 passages. One clone of A21 had been passaged for more than 100 times in nearly one and half year, and named immortalized mandibular condylar chondrocyte (IMCC). IMCCs were polygonal-shaped, similar to MCCs; the population doubling time of IMCC and MCC were 30.86 h and 78.95 h respectively. Subculture, freezing and recovering had no effect on cellular shape and proliferation of IMCC.

CONCLUSIONS

An immortalized cell cline derived from the rabbit MCC has been successfully established.

[ATP synthesis by free yeast catalysis coupling hollow fiber ultrafiltration separation]

A novel process for the ATP production employing free yeast catalysis and coupling a hollow fiber module ultrafiltration separation was studied. The experimental results of biocatalyst half-life and operating stability for ultrafiltration showed that the enzymes released from free yeast cell could be cut-off efficiently from the product output stream by hollow fiber membrane. The intercepted percentage of ADH and HK reached more than 95% during the steady running. The efficiency of enzymes utilized was 2.0-2.5 fold as much as that of batch reaction. And the time of yeast cells used repeatedly for ATP synthesis reached 2.5-3.0 batches. Under 0.1 MPa, the ultrafiltrating speed of hollow fiber membrane could keep on a stabilizing value for 11 batches continuously. The continuous operation mode of ATP synthesis simultaneous product ultrafiltration separation could be maintained in higher conversion rate for 5.0 h when the whole system fell in a pseudo-stat where the dilution rate was equal to 0.25 h-1.

[Hostility behavior as risk factor of coronary heart disease]

OBJECTIVE

To explore the relationships between hostility, and the risks of coronary-prone behavior and the clusters of unhealthy behaviors in individuals with different levels of hostility.

METHODS

A cross-sectional study was carried out among 1 010 male employees from two factories in Beijing Capital Steel and Iron Company in 1997. Data on major risks of cardiovascular, other social-demographic factors and levels of hostility by Cook-Medley Scales were collected.

RESULTS

Body mass index, amounts of cigarette smoking and alcohol drinking were significantly increased (P < 0.01) with a characteristic of reduced social support from one's colleagues, when individual's level of hostility increased. In addition, less years of education, higher prevalence of other chronic diseases (P < 0.05) and clustering of various unhealthy behaviors were found related to the increase of individual's hostility. The odds ratio in the group with highest hostility was 2.37 times higher than in the lowest one, after confounding effects from age, blood pressure, education level, status of chronic disease and social support being adjusted. No significant differences on both systolic and diastolic blood pressures among groups with different levels of hostility were discovered.

CONCLUSION

The association between hostility, coronary-prone risk behavior and cluster of unhealthy behaviors suggested that hostility might increase the risk of coronary heart diseases through affecting individual's behavior.

[Effect of yimai jiangya extract on plasma neuropeptide Y level in patients of senile hypertension with qi-deficiency and blood stasis syndrome]

OBJECTIVE

To observe the effect of Yimai Jiangya extract (YMJYE) on plasma neuropeptide Y (NPY) level in patients of senile hypertension at stage II with Qi-Deficiency and blood stasis Syndrome (QDBSS).

METHODS

Sixty-eight patients were randomly divided into two groups, 36 patients in the treated group treated with YMJYE and 32 patients in the control group treated with captopine. Radioimmunoassay was used to examine the level of plasma NPY before and after treatment in the two groups.

RESULTS

Before treatment, plasma NPY level was significantly higher in both groups than that in the old healthy persons (P < 0.01), it lowered significantly after treatment and the decrement was more obvious in the treated group in comparing with that in the control group (P < 0.01). Blood pressure was significantly lowered in both groups after treatment (P < 0.01) but with no significant difference between them.

CONCLUSION

Plasma NPY level was increased in patients of senile hypertension with QDBSS. YMJYE had good effect in lowering plasma NPY level and reducing blood pressure. It is presumed that the NPY lowering effect of YMJYE might be one of its mechanisms in lowering blood pressure.

PCD1, a novel gene containing PDZ and LIM domains, is overexpressed in several human cancers

In an effort to discover novel genes differentially expressed in human pancreatic cancer, we have identified a gene named PCD1 (pancreatic cancer derived) that is up-regulated in pancreatic dysplasia and cancer relative to normal pancreatic ductal epithelium. We cloned the full length (4572 bp) of this gene, which encodes a novel protein of 1064 amino acids containing a PDZ domain and a LIM domain. An alternatively spliced form with a deletion of 30 bp in the coding region was also found. In situ hybridization results showed that PCD1 is highly expressed in a significant percentage of colon, breast, liver, lung, pancreas, stomach, and prostate tumor tissues but is expressed in very few normal tissues. Northern blot hybridization confirmed the overexpression of PCD1 in colon and breast tumor tissues and also showed strong expression of PCD1 in the heart as well as in HeLa cells. Real-time quantitative reverse transcription-PCR verified the overexpression of PCD1 in primary colon tumors or in liver metastases relative to normal colon tissues in five of eight patients. The PCD1 gene maps to human chromosome 13q21.33. Because of its high levels of expression in neoplastic tissues and the presence of both PDZ and LIM domains, we suggest that PCD1 may play an important role in cytoskeletal reorganization during carcinogenesis.

[Allotransplantation of cultured fetal parathyroid gland cells in treating patients with hypoparathyroidism]

OBJECTIVE

To evaluate the therapeutic efficacy of transplantation of cultured human fetal parathyroid gland (chf-PTG) cells in treating patients with primary or secondary hypoparathyroidism.

METHODS

Chf-PTG cells were allotransplanted into the renal adipose capsules of 6 patients with hypoparathyroidism under the ultrasonic guidance. The levels of serum parathyroid hormone (PTH) and calcium were monitored by radioimmunometric assay (RIA) and biochemical method, respectively. Both indexes of pre-and post-operation were compared and the data were analyzed.

RESULTS

The levels of serum PTH and calcium were markedly elevated from three days to the first two weeks following transplantation of chf-PTG cells (P < 0.01). The PTH and calcium levels gradually stabilized from day 14 up to months 9-12, during which the symptoms of the patients alleviated or relieved.

CONCLUSION

The transplantation of chf-PTG cells is a potential method for treating patients with primary or secondary hypoparathyroidism.

[Clinical and experimental study on Shuanghua aerosol in treating infantile upper respiratory tract infection]

OBJECTIVE

To study the effect and mechanism of Shuanghua aerosol (SHA) in treating infantile upper respiratory tract infection (IURTI).

METHODS

In the clinical study, 276 cases of IURTI were randomly divided into two groups. The treated group was treated with SHA and the control group was treated with Shuanghuanglian aerosol (SHLA). In the experimental study, the effect of SHA on anti-inflammatory and anti-viral were observed.

RESULTS

The clinical total effective rate of SHA was 99.03% and its cure rate 65.38%, while those of the SHLA was 94.11% and 44.12% respectively, significant difference was shown between the two groups (P < 0.01). Experimental study showed that SHA could inhibit the xylol induced ear swelling and the egg white induced paw swelling in mice obviously, suppress the proliferation of influenza virus in rat's lung.

CONCLUSION

SHA has obvious anti-inflammatory and anti-viral effect, and has good curative effect in treating IURTI.

[Effect of yimai jiangya extract on platelet activation and fibrinolytic activity and angiotensin II in aged patients with essential hypertension]

OBJECTIVE

To observe the effect of Yimai Jiangya extract (YMJYE) on platelet alpha-granule membrane protein (GMP-140), tissue-type plasminogen activator (t-PA) and its inhibitor (PAI), angiotensin II (AngII) in aged patients with essential hypertension (EH) of stage 2 caused by Qi deficiency and blood stasis.

METHODS

Radioimmunoassay (RIA) and colorimetric analysis were used to examine the levels of GMP-140, t-PA, PAI and AngII before and after treatment with YMJYE in 42 aged patients (treated group), compared with that of 30 aged patients before and after treatment with captopril (control group) and 30 aged healthy subjects (healthy group).

RESULTS

Before treatment, GMP-140, PAI and AngII were significantly higher (P < 0.01), and t-PA were obviously lower (P < 0.01) in the treated and the control group compared with those in the healthy group. After treatment, the improvement of GMP-140, t-PA, PAI and AngII in the treated group were obvious (P < 0.05, P < 0.01). The improvement of GMP-140, t-PA, PAI in the treated group was more significant than that of control group (P < 0.05, P < 0.01), while the improvement of AngII in the treated group was worse than that of the control group (P < 0.01). After treatment, there was insignificant changes about the levels of blood pressure between the treated group and the control group (P > 0.05).

CONCLUSIONS

In the aged patients, GMP-140, PAI and AngII were increased, t-PA reduced. The effects of YMJYE in inhibiting platelet activation and improving fibrinolytic activity were better than that of captopril. These findings indicated that the mechanisms of inhibiting platelet activation and improving fibrinolytic activity and lowering blood pressure of YMJYE were correlated with decreasing the levels of AngII, but other mechanisms may also exist.

Identification of a novel aspartic-like protease differentially expressed in human breast cancer cell lines

Four different human breast cancer cell lines were examined to search for genes associated with tumor growth and metastasis. Each of these cell lines, MDA-MB-453, MCF-7, MDA-MB-231 and MDA-MB-435, displays different phenotypic characteristics ranging from poorly to highly tumorigenic and metastatic. The differences in gene expression profiles of these cell lines generated by differential display technique should allow one to identify candidates as putative oncogenes or tumor/metastasis suppressor genes. A novel cDNA expressed in the highly tumorigenic and metastatic cell line, MDA-MB-435, was identified and isolated by this approach. The function for this gene, designated ALP56 (aspartic-like protease 56 kDa), in tumor progression is suggested by the homology of the encoded protein to aspartic proteases, such as cathepsin D. The amino acid residues in two catalytic domains of this family are highly conserved in those domains of ALP56. Northern hybridization indicated that the expression of ALP56 is associated with growth and metastasis of MDA-MB-435 tumors in immunodeficient mice. In situ hybridization of biopsies from breast cancer and colon cancer patients indicated that ALP56 is upregulated in human primary tumors and liver metastasis. These results suggest that this novel gene correlates with human tumor progression.

[Immunohistochemical study of type I and type II collagen in the remodelling of the supraosseous tissue of mandibular condyle]

OBJECTIVE

Previous studies focused on the pathological changes of the supraosseous tissue of mandibular condyle (STMC), but little is known about extracellular matrix during the remodelling activity of temporomandibular joint (TMJ). This study will examine the characteristics of type I and type II collagen during this process.

METHODS

The animal model was established by extracting the left lower molars of adult rabbits. Temporomandibular joints of two sides were taken after 2 weeks, 1 month and 3 months respectively, and embedded in paraffin. Then 5 microns-thick sections were cut and processed for immunohistochemistry and haematoxylin-eosin staining. An immunohistochemical ABC method was used to determine the local changes of type I and type II collagen. The positive cells were counted in order to analyze quantitative changes.

RESULTS

After loss of teeth from 2 weeks to 3 months, the number and arrangement of chondrocytes changed. Some chondrocyte clusters were also observed in the non-extraction side of TMJ. Most STMC cells stained positively with anti-type I collagen, but weakly in chondrocytes and hypertrophic chondrocytes. On the other hand, type II collagen only existed in chondrocytes and some hypertrophic chondrocytes. The expression of type I collagen decreased after 2 weeks and became stronger after 1 and 3 months, furthermore distributed unevenly in STMC. Some hypertrophic chondrocytes in the non-extraction side showed strong positive staining with anti-type I collagen. Type II collagen in two sides decreased after 2 weeks, then became stronger after 1 and 3 month, but the whole level was less than that of the control group. Expressions of two kinds of collagen were compared between two sides. Type I collagen in the non-extraction side was stronger than that in the extraction side, while type II collagen had an opposite result.

CONCLUSION

Adult rabbits have a limited remodelling ability, and the synthesis and secretion of type I and type II collagen will change when the remodelling is beyond a proper extent, which will lead to impaired resistance and elasticity of fibrocartilage.

[Cost-effectiveness analysis of Beijing Fangshan cardiovascular prevention program in 1992 - 1997]

OBJECTIVE

To determine whether a community-based cardiovascular disease (CVD) intervention program, undertaken over six years, was cost-effective.

METHODS

Based on Beijing Fangshan Cardiovascular Disease Comprehensive Prevention Program, the cost for intervention and expenditure saved from caring for CVD in the communities with intervention from 1992 to 1997 were calculated, and cost-effectiveness analysis was performed using disability-adjusted life years (DALYs) gained as an indicator of effectiveness.

RESULTS

The cost for one DALY gained reduced gradually from 1992 to 1997, with an average ratio of cost to effectiveness of four to one (4:1). It cost annually 1,586.00, 1,380.20, -2,350.80, -905.30, -1,495.60 and -1,766.70 RMB yuan for one life-year saved, from 1992 to 1997 respectively, in a gradually decreasing trend with the increase in length of intervention. After intervention for two years, ratio of cost to effectiveness has become negative since 1994, which meant a positive benefit from intervention. Sensitivity analysis showed that ratio of cost to effectiveness was little sensitive to the changes in discount rate, weight of age and increase in cost of hospitalization for stroke and coronary heart disease, which reflected its reliability.

CONCLUSION

Community-based comprehensive intervention for CVD in rural population is cost-effective.

Crystal structure of the VHS and FYVE tandem domains of Hrs, a protein involved in membrane trafficking and signal transduction

We have determined the 2 A X-ray structure of the 219-residue N-terminal VHS and FYVE tandem domain unit of Drosophila Hrs. The unit assumes a pyramidal structure in which the much larger VHS domain (residues 1-153) forms a rectangular base and the FYVE domain occupies the apical end. The VHS domain is comprised of an unusual "superhelix" of eight alpha helices, and the FYVE domain is mainly built of loops, two double-stranded antiparallel sheets, and a helix stabilized by two tetrahedrally coordinated zinc atoms. The two-domain structure forms an exact 2-fold-related homodimer through antiparallel association of mainly FYVE domains. Dimerization creates two identical pockets designed for binding ligands with multiple negative charges such as citrate or phosphatidylinositol 3-phosphate.

Probing the structure of the PI-SceI-DNA complex by affinity cleavage and affinity photocross-linking

The PI-SceI protein is an intein-encoded homing endonuclease that initiates the mobility of its gene by making a double strand break at a single site in the yeast genome. The PI-SceI protein splicing and endonucleolytic active sites are separately located in each of two domains in the PI-SceI structure. To determine the spatial relationship between bases in the PI-SceI recognition sequence and selected PI-SceI amino acids, the PI-SceI-DNA complex was probed by photocross-linking and affinity cleavage methods. Unique solvent-accessible cysteine residues were introduced into the two PI-SceI domains at positions 91, 97, 170, 230, 376, and 378, and the mutant proteins were modified with either 4-azidophenacyl bromide or iron (S)-1-(p-bromoacetamidobenzyl)-ethylenediaminetetraacetate (FeBABE). The phenyl azide-coupled proteins cross-linked to the PI-SceI target sequence, and the FeBABE-modified proteins cleaved the DNA proximal to the derivatized amino acid. The results suggest that an extended beta-hairpin loop in the endonuclease domain that contains residues 376 and 378 contacts the major groove near the PI-SceI cleavage site. Conversely, residues 91, 97, and 170 in the protein splicing domain are in close proximity to a distant region of the substrate. To interpret our results, we used a new PI-SceI structure that is ordered in regions of the protein that bind DNA. The data strongly support a model of the PI-SceI-DNA complex derived from this structure.

[The diagnostic value of 13C-urea breath test in Helicobacter pylori colonization density and the severity of gastritis]

OBJECTIVE

To evaluate the diagnostic value of (13)C-urea breath test (UBT) in Helicobacter pylori (Hp) colonization density and the severity of gastritis.

METHODS

The diagnostic accuracy of UBT in the diagnosis of Hp infection with reference to histology (HE and Warthin-Starry stain) was analyzed and the UBT results (DOB values) among the groups of gastritis with different degrees of severity were compared.

RESULTS

By using UBT, 96 of 103 patients with Hp -positive histology were detected (sensitivity, 93.2%), the specificity was 89.1%. DOB value in the Hp colonization dense group was significantly higher than in the other groups (low and moderately dense) (P < 0.05). A significant but weak, correlation was found between the DOB values and the colonization density either with (rs = 0.599 0, P < 0.000 1) or without (r(s) = 0.245 7, P = 0.015 8) inclusion of histologically negative patients. In Hp positive patients, DOB values neither in the groups of active gastritis (0 - 3 grade) nor in the groups of chronic gastritis (1 - 3 grade) had no significant difference. There was no correlation between DOB values and severity of inflammatory infiltration.

CONCLUSION

(13)C-UBT has high sensitivity and specificity in the detection of Hp infection. There is significant but weak, correlation between DOB values and the colonization density of Hp. DOB values could not reflect the density of neutrophil and lymphocyte infiltration.

[Analysis of genome character and amino acid residues 2,209 to 2,248 of NS5 A region of hepatitis C virus in relation to the response to interferon therapy]

OBJECTIVE

To observe nucleotide sequence variations and amino acid residues 2,209 to 2,248 of the NS5 A region of hepatitis C virus in relation to interferon therapy in Chinese patients infected with HCV genotype 1b.

METHODS

We collected sera from 22 patients infected with HCV genotype 1b, performed nested RT-PCR using extracted serum RNA from sera, amplified NS5 A region 2,209 to 2,248 and sequenced the PCR product directly. The deduced amino acid sequences were compared with the corresponding region of the HCV-J prototype strain.

RESULTS

Only 4 isolates were intermediate type, and no mutant type was found. In 18 patients treated with IFN-alpha, only 4 were HCV RNA negative at present, No correlation was found between amino acid mutation and IFN response.

CONCLUSION

Variations in the NS5 A region between amino acid residues 2,209 to 2,248 failed to predict IFN response in Chinese patients infected with HCV genotype 1b. IFN may accelerate nucleotide variation but has little influence on amino acid variations.

[A study on the endotoxin and bacterial contamination in reverse osmosis water and dialysis fluids]

OBJECTIVE

To evaluate the endotoxin (ET) and the bacterial contamination in reverse osmosis (RO) water and dialysis fluids for hemodialysis treatment.

METHODS

Specimens of RO water and dialysis fluids were obtained at random from 18 hospitals in Beijing. ET was measured with chromogenic limulus amoeboeyte lysate (LAL) assay. Bacteriologic samples were processed on heterotrophic plate count agar with pour plate technique. The plasma IL-1, IL-6 and TNFalpha were tested with enzyme-linked immunosorbent assay (ELISA).

RESULTS

The level of ET in RO water was 0.116 +/- 0.063 EU/ml, and the culture of bacteria had 2 positive results, both counting 100 CFU/ml. The level of ET was much higher in acid concentrate (Protocol B) than in basic concentrate (Protocol A). The culture of bacteria had 11 positive results in Protocol B concentration with 8 samples equal or higher than 2,000 CFU/ml. The culture of bacteria had only 3 positive results in Protocol A concentration, all being lower than 2,000 CFU/ml. Another investigation showed that the level of ET in dialysis inlet was higher than 0.5 EU/ml in 5 cases of a total of 16. Their plasma IL-1 and TNFalpha levels were significantly increased.

CONCLUSION

Both ET and bacterial contamination exist in RO water and dialysate. It is essential to examine the level of ET and perform bacterial culture, as well as to disinfect RO and dialysate tank at regular intervals in order to reduce pyrogenic reactions.

Mapping of a DNA binding region of the PI-sceI homing endonuclease by affinity cleavage and alanine-scanning mutagenesis

The PI-SceI protein is a member of the LAGLIDADG family of homing endonucleases that is generated by a protein splicing reaction. PI-SceI has a bipartite domain structure, and the protein splicing and endonucleolytic reactions are catalyzed by residues in domains I and II, respectively. Structural and mutational evidence indicates that both domains mediate DNA binding. Treatment of the protein with trypsin breaks a peptide bond within a disordered region of the endonuclease domain situated between residues Val-270 and Leu-280 and interferes with the ability of this domain to bind DNA. To identify specific residues in this region that are involved in DNA binding and/or catalysis, alanine-scanning mutagenesis was used to create a set of PI-SceI mutant proteins that were assayed for activity. One of these mutants, N281A, was >300-fold less active than wild-type PI-SceI, and two other proteins, R277A and N284A, were completely inactive. These decreases in cleavage activity parallel similar decreases in substrate binding by the endonuclease domains of these mutant proteins. We mapped the approximate position of the disordered region to one of the ends of the 31 base pair PI-SceI recognition sequence using mutant proteins that were substituted with cysteine at residues Asn-274 and Glu-283 and tethered to the chemical nuclease FeBABE. These mutational and affinity cleavage data strongly support a model of PI-SceI docked to its DNA substrate that suggests that one or more residues identified here are responsible for contacting base pair A/T(-)(9), which is essential for substrate binding.

Entry of porcine reproductive and respiratory syndrome virus into porcine alveolar macrophages via receptor-mediated endocytosis

Porcine alveolar macrophages (AMphi) are the dominant cell type that supports the replication of porcine reproductive and respiratory syndrome virus (PRRSV) in vivo and in vitro. In order to determine the characteristics of the virus-receptor interaction, the attachment of PRRSV to cells was examined by using biotinylated virus in a series of flow cytometric assays. PRRSV bound specifically to AMphi in a dose-dependent manner. Binding of PRRSV to AMphi increased gradually and reached a maximum within 60 min at 4 degrees C. By confocal microscopy, it was shown that different degrees of PRRSV binding exist and that entry is by endocytosis. Virus uptake in vesicles is a clathrin-dependent process, as it was blocked by the addition of cytochalasin D and co-localization of PRRSV and clathrin was found. Furthermore, by the use of two weak bases, NH4Cl and chloroquine, it was demonstrated that PRRSV uses a low pH-dependent entry pathway. In the presence of these reagents, input virions accumulated in large vacuoles, indicating that uncoating was prevented. These results indicate that PRRSV entry into AMphi involves attachment to a specific virus receptor(s) followed by a process of endocytosis, by which virions are taken into the cell within vesicles by a clathrin-dependent pathway. A subsequent drop in pH is required for proper virus replication.

Nanocrystalline Silver Particles: Synthesis, Agglomeration, and Sputtering Induced by Electron Beam

Nanocrystalline silver particles with an average size of 15 nm have been prepared by reducing Ag(NH3)+2 with N2H4. H2O, with sodium dodecylbenzene sulfate (DBS) used as the stabilizing agent. The influence of DBS in the reaction is discussed. When the so-prepared silver particles were observed in situ under a transmission electron microscope, we observed an agglomeration and sputtering phenomenon induced by the electron beam. The possible reason for agglomeration and sputtering is proposed. Silver crystals of hexagonal shape, ranging from 20- to 120-nm in size, were formed on a copper grid. This phenomenon may offer a useful means of forming small particles. Copyright 1999 Academic Press.

[A histopathological study on Hunan aqueous drainage implantation in rabbit's eye]

Thirty eyes with 15 healthy white New Zealand rabbits subgrouped into two groups: right eye as an experimental group which was implanted Hunan aqueous drainage (HAD) and left eye served as self-control group in which a silicone band 7 mm in width and 7 to 10 mm in length was placed equatorially around the globe. Within 1 to 12 weeks postoperatively, we examined the anterior segment of the globe by the slit lamp microscopy (SLM) and made histopathological observation under light microscope after sacrifice and enucleation of eyeballs in five batches. SLM examination showed that 8 out of 15 eyes in experimental group showed mild or moderate ocular reaction which subsided within 2 to 14 days postoperatively. Histopathological observation revealed no obvious pathological lesions in the uveal tract tissues in the most globes. No foreign body macrophages were found. It indicates that HAD implant is nontoxic and nonallergenic, so it is adaptable for rabbit ocular tissue. The HAD implant can be used in human eyes, too.