Inhibition of tumorigenesis by intratumoral delivery of the circadian gene mPer2 in C57BL/6 mice

Biological clocks are intrinsic time-keeping systems that regulate behavior and physiological functions in most living organisms. Previous works suggested a possible link between the endogenous circadian clock and cell cycle regulation. The mammalian Period-2 gene (mPer2), an important component of the circadian clock mechanism, is recently demonstrated to play an important role in repressing tumor growth. In this study, we found that polyethylenimine-mediated intratumoral Per2 gene delivery had significant antitumor effects in C57BL/6 mice transplanted with Lewis lung carcinoma. Our data illustrated that the Per2 gene delivery inhibited PCNA expression and induced apoptosis. Our results support the emerging role of the circadian clock in critical aspects of tumorigenesis. These findings underscore the potential use of Per2 gene delivery as a novel therapeutic intervention for the treatment of malignant tumors.

Association of the 54-nucleotide repeat polymorphism of hPer3 with heroin dependence in Han Chinese population

Circadian clock genes have the function of producing circadian rhythm. They are also implicated in the origin or development of many diseases such as cancers and neuropsychiatric diseases. The purpose of this study is to determine whether the 54-nucleotide repeat polymorphism of hPer3, one of the circadian clock genes, associates with heroin dependence. DNA samples were obtained from 209 Chinese heroin-dependent subjects and 249 Chinese healthy controls. The 54-nucleotide repeat polymorphism was detected by polymerase chain reaction and DNA agarose gel electrophoresis. The frequency of four-repeat allele was significantly higher (chi(2)= 10.64, P = 0.001; corrected for multiple tests, P = 0.003) in the mixed gender heroin-dependent subject group (four repeat: 0.89, five repeat: 0.11) than in the mixed gender control group (four repeat: 0.81, five repeat: 0.19); the frequency of four-repeat allele was also significantly higher (chi(2)= 10.00, P = 0.002; corrected for multiple tests, P = 0.006) in the male heroin-dependent subject group (four repeat: 0.89, five repeat: 0.11) than in the male control group (four repeat: 0.81, five repeat: 0.19); for females, no significant trend was observed with the 54-nucleotide repeat polymorphism between the heroin-dependent subject group and the control group. Our results suggest that the 54-nucleotide repeat polymorphism of hPer3 significantly associates with heroin dependence at the allele frequency level and may be a potential risk factor for the development of heroin dependence.

The extracellular signal-regulated kinase signaling pathway is involved in the modulation of morphine-induced reward by mPer1

Although there are clear interactions between circadian rhythms and drug addiction, mechanisms for such interactions remain unknown. Studies have shown that the circadian clock gene Period in Drosophila melanogaster could influence behavioral responses to cocaine, and the mouse homologues, mPer1 and mPer2, modulate cocaine sensitization and reward. In the present study, we applied DNAzyme targeting mPer1 to interfere the expression of mPer1 in CNS in mice, and studied its effects on morphine-induced reward and its molecular mechanism. The results demonstrated that the DNAzyme could attenuate the expression of mPer1 in CNS in mice and downregulate the increased extracellular signal-regulated kinase (ERK) activity induced by morphine in whole brain and the nucleus accumbens, the key region of drug addiction. Mice treated with morphine and injected intracerebroventricularly with DNAzyme did not show preference to the morphine-trained side. These results indicate that drug dependence seems to be influenced at least partially by mPer1 and its mechanism may involve the ERK signal pathway.

Obesity risk associated with the K121Q polymorphism of the glycoprotein PC-1 gene

BACKGROUND

Obesity is considered to be a multifactorial trait resulting from the combined influence of genetic and environmental determinants. Insulin resistance plays an important role in the development of obesity. Plasma-cell membrane differentiation antigene-1 (PC-1) inhibits insulin receptor signalling when overexpressed and thus causes insulin resistance. PC-1 gene polymorphism might be associated with adipocyte metabolism disturbance and energy imbalance. The purpose of this study was to determine whether K121Q polymorphism in PC-1 gene is involved in obesity susceptibility in Chinese Han population.

METHODS

The genotype of the polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism analysis for 338 unrelated subjects of Beijing, China. Their Body mass index (BMI), plasma glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL), free fatty acid (FFA) and insulin level were measured. Chi-square analyses were applied to test the significance differences in genotypic and allelic frequencies. Association studies were undertaken using the t-test and logistic regression analyses.

RESULTS

The obese had significantly higher frequency of KQ/QQ genotype or Q allele than non-obese in females (26.7% vs. 10.9%, p = 0.014 and 13.3% vs. 5.5%, p = 0.021). Significant elevation of insulin amongst the Q121 carrier women in obesity individuals and higher FFA level of Q121 carrier men in non-obese controls (BMI < or = 23 kg/m2) were observed. Binary logistic regression analysis revealed that PC-1 genotype together with higher glucose, total cholesterol, triglyceride and serum HDL were independently associated with the presence of obesity.

CONCLUSIONS

The observed genotype distributions revealed a significant association of PC-1 K121Q with obesity. PC-1 Q121 carriers are more likely to be insulin-resistant or get fatter in respect to KK subjects and carriers of the Q allele are at higher risk for the development of obesity in female.

Abnormal changes of plasma acute phase proteins in schizophrenia and the relation between schizophrenia and haptoglobin (Hp) gene

In this study we focused on detecting schizophrenia related changes of plasma proteins using proteomic technology and examining the relation between schizophrenia and haptoglobin (Hp) genotype. We investigated plasma proteins from schizophrenic subjects (n = 42) and healthy controls (n = 46) by two-dimensional gel electrophoresis (2-DE) in combination with mass spectrometry. To further reveal the genetic relationship between acute phase proteins (APPs) and schizophrenia disease, we tested Hp alpha1/Hp alpha2 (Hp 1/2) polymorphism and two single nucleotide polymorphisms (SNPs) of Hp, rs2070937 and rs5473, for associations with schizophrenia in the Chinese Han population. With the relatively high number of samples for 2-DE work, we found that four proteins in the family of positive APPs were all up-regulated in patients. In genetic association study, we found significant associations existing between schizophrenia and Hp polymorphisms, Hp 1/2 and rs2070937 variants. Schizophrenia is accompanied by both an altered expression of Hp protein and a different genotype distribution of Hp gene, demonstrating that Hp is associated with schizophrenia. The results from proteomic and genomic aspects both indicate that acute phase reaction is likely to be an aetiological agent in the pathophysiology of schizophrenia, but not just an accompanying symptom. The positive APPs are schizophrenic related proteins, with the highly concordant results on four positive APPs.

Relationship between the regulatory region polymorphism of human tissue kallikrein gene and essential hypertension

Ten alleles with length and nucleotide sequence variations were identified in the regulatory region of human tissue kallikrein gene. This present study aimed to study the polymorphisms of the regulatory region of human tissue kallikrein gene of the Chinese and investigate the relationship of the polymorphisms with essential hypertension. A case-control study was conducted in 200 hypertensive and 200 normotensive subjects of unrelated Chinese Han origin. All subjects were aged from 30 to 70 years and had no history of diabetes mellitus, kidney failure, or thyroid gland disease. The alleles were detected by polymerase chain reaction (PCR) and genotyping was performed with allele-specific oligonucleotide analysis (ASO). Data from the essential hypertensive and control subjects were statistically analysed by the Student's t-test and chi2-test. The age- and gender-matching of the groups were accurate. The case group and the control group were in Hardy-Weinberg equilibrium at this locus (cases, P=0.313; control subjects, P=0.457). There were nine alleles among the case and control groups, and the allele frequencies were found to be significantly different between cases and controls (chi2=25.701, P<0.001). The genotype frequencies were also significantly different (chi2=70.100, P<0.001) between these two groups. In conclusion, there are polymorphisms in the regulatory region of human tissue kallikrein gene in the Chinese Han people. Differences in both allele frequencies and genotype frequencies between these two groups have provided evidence towards the association of hypertension with the polymorphisms in this studied site.

The role of mPer1 in morphine dependence in mice

Investigations using Drosophila melanogaster have shown that the circadian clock gene period can influence behavioral responses to cocaine, and the mouse homologues, mPer1 and mPer2, modulate cocaine sensitization and reward. In the present study, we applied DNAzyme targeting mPer1 to interfere the expression of mPer1 in CNS in mice and studied the role of mPer1 on morphine dependence. We found that the DNAzyme could attenuate the expression of mPer1 in CNS in mice. Mice treated with DNAzyme and morphine synchronously did not show preference to the morphine-trained side, whereas the control group did. In contrast, mice treated with DNAzyme after morphine showed preference to the morphine-trained side as well as the control group did. These results indicate that drug dependence seems to be influenced at least partially by mPer1, but mPer1 cannot affect morphine dependence that has been formed.

Use of a quantitative gene expression assay based on micro-array techniques and a mathematical model for the investigation of chlamydial generation time

Chlamydia is an important pathogen which possesses a unique developmental cycle. We used real-time PCR technology to measure gene transcript levels in Chlamydia trachomatis strain L2. By measuring 16S rRNA transcript levels, and developing a mathematical model of the chlamydial developmental cycle fitting the data, we predict an average generation time of approximately 2.6 h. Additionally, potentially this modelling also provides the foundation for the application of emerging micro-array technology in which identification of the gene signals that trigger a chlamydial body to start replicating or transform to its infectious form can be made possible.

Novel PCR-EIA method for the detection of Chlamydia pneumoniae in respiratory specimens

We report the development of a microtitre plate-based PCR-EIA assay (ELAHA; Enzyme Linked Amplification and Hybridization Assay) for the sensitive and specific detection of Chlamydia pneumoniae in sputum samples from patients with chronic obstructive airways disease (COAD). Following PCR amplification of a segment of the chlamydial heat shock 60 protein gene, the 587 bp sized amplicon is captured onto the streptavidin coated surface of a microtitre plate using a C. pneumoniae specific biotinylated probe and the level of captured product is subsequently determined via a colorimetric reaction using an automated plate reader. The ELAHA is a simple, rapid and inexpensive method for detection of low levels of infectious agents and is readily adaptable to current clinical laboratory equipment. The assay was evaluated with a cohort of hospital respiratory patients: (i) COAD patients with acute exacerbation, (ii) COAD patients without exacerbation (stable) and (iii) a non-respiratory control group. The ELAHA produced 6/12 (50%) C. pneumoniae positives in the COAD with exacerbation group, 3/13 (23%) positives in the COAD without exacerbation group and only 1/6 (17%) positives in the control non-respiratory group. This sensitive and robust PCR-EIA method can provide clinically relevant diagnostic evidence of current C. pneumoniae infection contributing to serious respiratory tract diseases such as COAD.

The anticancer drug-DNA complex: femtosecond primary dynamics for anthracycline antibiotics function

The anthracycline-DNA complex, which is a potent agent for cancer chemotherapy, has a unique intercalating molecular structure with preference to the GC bases of DNA, as shown by Rich's group in studies of single-crystal x-ray diffraction. Understanding cytotoxicity and its photoenhancement requires the unraveling of the dynamics under the solution-phase, physiological condition. Here we report our first study of the primary processes of drug function. In a series of experiments involving the drug (daunomycin and adriamycin) in water, the drug-DNA complexes, the complexes with the four nucleotides (dGTP, dATP, dCTP, and dTTP), and the drug-apo riboflavin-binding protein, we show the direct involvement of molecular oxygen and DNA base-drug charge-separation-the rates for the reduction of the drug and dioxygen indicate the crucial role of drug/base/O(2) in the efficient and catalytic redox cycling. These dynamical steps, and the subsequent reactions of the superoxide product(s), can account for the photoenhanced function of the drug in cells, and potentially for the cell death.

Femtosecond dynamics of a drug-protein complex: daunomycin with Apo riboflavin-binding protein

In this contribution, we report studies of the primary dynamics of the drug-protein complexes of daunomycin with apo riboflavin-binding protein. With femtosecond resolution, we observed the ultrafast charge separation between daunomycin and aromatic amino acid residues of the protein, tryptophan(s). Electron transfer occurs from tryptophan(s) to daunomycin with two reaction times, 1 ps and 6 ps, depending on the local complex structure. The formation of anionic daunomycin radical is crucial for triggering a series of chemical reactions in redox cycling. One of the subsequent reactions is the reduction of dioxygen to form active superoxide by the reduced daunomycin. This catalytic process was found to occur within 10 ps. In the absence of dioxygen, charge recombination takes a much longer time, more than 100 ps. These results, along with similar findings in DNA and nucleotides, elucidate that the ultrafast generation of reduced daunomycin radicals by photoactivation is a primary step for the observed photoenhancement of drug cytotoxicity by several orders of magnitude. We also studied the dependence of the dynamics on protein conformations at different ionic strengths and denaturant concentrations. We observe a sharp transition from the tertiary structure to the unfolding state at 2 M of denaturant concentration.

Giant Hall effect in nonmagnetic granular metal films

Nearly 3 orders of magnitude enhancement in the Hall coefficient is observed in Cu(x)-(SiO(2))(1--x) granular films. This large enhancement of the Hall coefficient not only is significantly larger than the prediction of the classical percolation theory, but also occurs at a metal concentration identified to be the quantum percolation threshold. Measurements of the electron dephasing length and magnetoresistance, plus the TEM characterization of microstructures, yield a physical picture consistent with the mechanism of the local quantum interference effect.

[Investigation on an outbreak of Legionnaires' disease caused by Lboz in a suburb of Beijing]

OBJECTIVE

To demonstrate the infectious rates and incidence rates through epidemiological investigation.

METHODS

Serum samples from 203 new soldiers were detected from Lboz by TAT.

RESULTS

Infectious rates was 33.00% (67/203), and the incidence rates was 8.87% (18/203) with 2 cases of pneumonic type and 16 cases of pontiac fever type.

CONCLUSION

The results suggested that an outbreak of Legionnaires' desease caused by Legionella bozemanii (Lboz) took place in a suburb of Beijing. However the report of the outbreak caused by Lboz had not been found in related references.

[Influence of different clipping intensity and R/FR ratio in light radiation on tillering of weeping lovegrass]

Pot experiment with weeping lovegrass was conducted laboratory in the Department of Rangeland, Wildlife and Fisheries Management, Texas Tech University in 1996. The plants grown in green house were used to study the effect of different clipping intensities on tillering, and those grown in laboratory were used to study the interaction between different R/FR(red/farred) ratio of the light reaching to the lower strata of the canopy and different clipping intensities on tillering. The results show that increasing clipping intensity decreased the net gain tillers, bt R/FR ratio had no significant effect on tillering, except no clipping treatment. The compensatory growth effect of tillering did not existed at all clipping intensities, but the elongation speed of young leaves quickened with clipping intensities. It is suggested that suitable utilization, intensified utilization and no utilization were all not beneficial to the growth and development of weeping lovegrass.

[A pilot study on the value of duplex polymerase chain reaction method in early diagnosis of Legionella pneumonia]

OBJECTIVE

To investigate the value of duplex polymerase chain reaction (DPCR) in early diagnosis of Legionella pneumonia by detecting Legionella DNA in sputum and bronchoalveolar lavage fluid(BALF).

METHODS

During the process of DPCR, two different sets of oligonucleotide primers were simultaneously used to amplify 386bp 16SrRNA gene fragment and 206bp mip gene fragment. These two primers were designed according to the sequences of 16SrRNA gene and mip gene of Legionella. The sputum and BALF of patients from two groups, including a Legionella pneumonia group (n = 15) and an ordinary pneumonia group (n = 31) were collected at early course of the disease. All of the samples were detected with DPCR for Legionella DNA. Simulated samples were also detected to investigate the sensitivity of the method for testing clinical samples.

RESULTS

All the samples collected from the Legionella pneumonia patients, including 25 of sputum,and 8 of BALF showed positive DPCR. The results of DPCR, which could distinguish Legionella pneumophila from non-pneumophila Legionella spp. to some degree, were in good accordance with those of the specific serum antibodies. All of the samples from the ordinary pneumonia group including 40 of sputum and 16 of BALF demonstrated negative DPCR. Different samples of the same patient showed the same DPCR results. The lowest detection level of simulated sputum sample was the same as that of simulated BALF sample, being 1 x 10(3) cfu/ml.

CONCLUSIONS

This preliminary study showed that DPCR had satisfactory sensitivity, specificity and stability for detecting Legionella DNA in sputum and BALF. The method is of value in early diagnosis of Legionella pneumonia. Its wide use for clinical work requires further investigation.

An amplified fragment length polymorphism map of the silkworm

The silkworm (Bombyx mori L.) is a lepidopteran insect with a long history of significant agricultural value. We have constructed the first amplified fragment length polymorphism (AFLP) genetic linkage map of the silkworm B. mori at a LOD score of 2.5. The mapping AFLP markers were genotyped in 47 progeny from a backcross population of the cross no. 782 x od100. A total of 1248 (60.7%) polymorphic AFLP markers were detected with 35 PstI/TaqI primer combinations. Each of the primer combinations generated an average of 35.7 polymorphic AFLP markers. A total of 545 (44%) polymorphic markers are consistent with the expected segregation ratio of 1:1 at the significance level of P = 0.05. Of the 545 polymorphic markers, 356 were assigned to 30 linkage groups. The number of markers on linkage groups ranged from 4 to 36. There were 21 major linkage groups with 7-36 markers and 9 relatively small linkage groups with 4-6 markers. The 30 linkage groups varied in length from 37.4 to 691.0 cM. The total length of this AFLP linkage map was 6512 cM. Genetic distances between two neighboring markers on the same linkage group ranged from 0.2 to 47 cM with an average of 18.2 cM. The sex-linked gene od was located between the markers P1T3B40 and P3T3B27 at the end of group 3, indicating that AFLP linkage group 3 was the Z (sex) chromosome. This work provides an essential basic map for constructing a denser linkage map and for mapping genes underlying agronomically important traits in the silkworm B. mori L.

Femtosecond direct observation of charge transfer between bases in DNA

Charge transfer in supramolecular assemblies of DNA is unique because of the notion that the pi-stacked bases within the duplex may mediate the transport, possibly leading to damage and/or repair. The phenomenon of transport through pi-stacked arrays over a long distance has an analogy to conduction in molecular electronics, but the mechanism still needs to be determined. To decipher the elementary steps and the mechanism, one has to directly measure the dynamics in real time and in suitably designed, structurally well characterized DNA assemblies. Here, we report our first observation of the femtosecond dynamics of charge transport processes occurring between bases within duplex DNA. By monitoring the population of an initially excited 2-aminopurine, an isomer of adenine, we can follow the charge transfer process and measure its rate. We then study the effect of different bases next to the donor (acceptor), the base sequence, and the distance dependence between the donor and acceptor. We find that the charge injection to a nearest neighbor base is crucial and the time scale is vastly different: 10 ps for guanine and up to 512 ps for inosine. Depending on the base sequence the transfer can be slowed down or inhibited, and the distance dependence is dramatic over the range of 14 A. These observations provide the time scale, and the range and efficiency of the transfer. The results suggest the invalidity of an efficient wire-type behavior and indicate that long-range transport is a slow process of a different mechanism.

Fundus microvascular flow monitoring during retrograde cerebral perfusion: an experimental study

BACKGROUND

Retrograde cerebral perfusion (RCP) through the superior vena cava was clinically introduced as a supportive technique to protect the brain during deep hypothermic circulatory arrest. This study searched for a direct monitor of cerebral blood flow to evaluate the effect of cerebral perfusion.

METHODS

Retinal microvascular perfusions were studied in six piglets using fundus fluorescein angiography (FFA) and color Doppler sonography before cardiopulmonary bypass and retrograde cerebral perfusion during deep hypothermic circulatory arrest.

RESULTS

FFA showed initial filling of the fundus venae in 2.5 minutes, and complete filling in 4.5 minutes with partial filling of the arteriae. Arteriae completely filled in 8 minutes, and all of the arteriae and venae filled from 15 to 17 minutes. Color Doppler sonography showed that flow signals were detected in all of the fundus vessels during RCP.

CONCLUSIONS

FFA and color Doppler sonography are direct and sensitive methods for observing cerebral blood flow and assessing the effect of cerebral perfusion.

[Effects of electromagnetic radiation from cellular telephone handsets on symptoms of neurasthenia]

In order to study the effects of electromagnetic radiation from cellular telephone handsets on symptoms of neurasthenia, 115 and 101 persons with or without handsets were selected. The subjects were investigated by questionnaire on their general health, lifestyle, habit, mental stress, the frequency of using the handsets, living and working environment, the cases of suffered from diseases and symptoms of neurasthenia. The data were analyzed by Chi-square test and Logistic regression statistics. The results showed that the time of using handset was positively associated with depression (P < 0.05), nausea (P < 0.01) and loss of appetite(P < 0.05). The results showed that long time use of cellular telephone handset could induce the symptoms of neurasthenia.

[Researches on surface modification for prevention of bacterial adhesion to implanting biomaterials]

The failure of operation caused by biomaterials centered infections (BCI) has seriously restricted the clinical application of biomaterials. Two mechanisms of bacterial adhesion and the relationship between surface free energy of bimaterials and bacterial adhesion are introduced and discussed in this paper. Increasing the surface free energy can improve (decrease) the adhesion of some kinds of bacteria. At last, some methods of the surface modification are reviewed.

[Modification of surface of Dacron materials by UV irradiation for prevention of microbial adhesion]

UV irradiation grafting method was used to modify the surface of Prosthetic Valve materials (Dacron) for prevention of bacteria-adhesion, and PEG was introduced to the surface of Dacron by this method. The result showed that the chemical magnifying effect of PEG improved the grafting of heparin on the material surface. This method can obviously reduce the number of adherent bacteria.

Design of infection-resistant antibiotic-releasing polymers: I. Fabrication and formulation

Biomaterials-related infections are often observed with prosthetic implants and in many cases result in the failure of the devices. To design a biomedically useful polymer that is intrinsically infection-resistant, we have developed a ciprofloxacin-loaded polyurethane (PU) matrix that releases antibiotic locally at the implant surface, thereby minimizing bacterial accumulation. We report here the methods of fabrication and formulation for making such antibiotic-loaded devices, as well as evidence of their bactericidal properties. Specifically, various pore-forming agents and drug loadings were examined. An optimum formulation consisting of BIOSPAN PU, poly(ethylene glycol) and ciprofloxacin offered the longest effective period of sustained release (5 days). The bactericidal efficacy of the released ciprofloxacin against Pseudomonas aeruginosa (PA) was four times that of the control PU without antibiotics. This bactericidal efficiency was due to an increase in the PA detachment from the surface. These observations suggested that the released ciprofloxacin was biologically active in preventing the bacteria from permanently adhering to the substratum, and thus decreasing the possibility of biofilm-related infection.

Randomised trial of different rates of feeding in acute diarrhoea

OBJECTIVE

To compare the effect of different feeding frequencies on the speed of recovery from diarrhoea.

METHODS

A randomised, non-blinded trial provided 0.452 MJ/kg/day as either 6 or 12 feeds of cows' milk each day to 262 hospitalised male infants aged 3-12 months with acute diarrhoea. Stool frequency, stool weight, body weight, and diarrhoea complications were monitored until recovery or for 14 days.

RESULTS

A proportional hazards regression model controlling for age, diarrhoea aetiology, and severity of dehydration on admission revealed that the frequently fed group had a significantly shorter duration of diarrhoea (hazards ratio, 1.29; 95% confidence interval, 1.002 to 1.653). Frequently fed infants had a significantly greater weight gain and significantly lower faecal frequency and faecal weight.

CONCLUSIONS

Breast feeding remains the preferred method of feeding infants with acute diarrhoea, but feeding cows' milk to adequately nourished infants with acute diarrhoea is safe and is more rapidly effective if provided in frequent feeds with low energy loads.

[Modification of the surface of prosthetic valve material by LGDP for protection against microbial adhesion]

This study aimed at the surface modification of prosthetic valve materials by means of cold glow discharge plasma. Orthogonal design was adopted to select the optimal scheme by the experiments of the singular factor, such as output power, gas flow rate, treatment time etc. The PEG-200 was introducted to the surface. Grafting a layer of heparin onto the surface; coating a layer of PEG-like onto the surface first, and then the grafting heparin. Comparing the adhesive amounts of staphylococcus epidermidis (SE), the adhesive curves for Dacron, which was treated by the above methods; the last one is the best.

[Markov process method in analyzing longitudinal quality of life data]

OBJECTIVE

To present a method to analyze longitudinal quality of life data and discuss some relevant questions.

METHOD

Based on the theories of Markov process, the Markov method was presented and used to analyze the change of quality of life status for 212 cases being detoxificated drug addicts and their influence factors.

RESULTS

The intensity coefficients of status transient for 1-->2 and 2-->3 for occupation were 0.7912 and 0.6797 respectively; the coefficients for status 1-->2 for the detoxification time was 0.5663 and that for 2-->3 for the detoxification method was 0.2765.

CONCLUSIONS

The Markov method is good to analyze longitudinal quality of life data for it can analyze both the transient probabilities between any two status of quality of life and their influence factors. The results showed that the occupation of drug addicts, the detoxification time and method can affect the change of quality of life.

Femtosecond dynamics of DNA-mediated electron transfer

Diverse biophysical and biochemical studies have sought to understand electron transfer (ET) in DNA in part because of its importance to DNA damage and its repair. However, the dynamics and mechanisms of the elementary processes of ET in this medium are not fully understood and have been heavily debated. Two fundamental issues are the distance over which charge is transported and the time-scale on which the transport through the pi-stack of the DNA base pairs may occur. With femtosecond resolution, we report direct observation in DNA of ultrafast ET, initiated by excitation of tethered ethidium (E), the intercalated electron acceptor (A); the electron donor (D) is 7-deazaguanine (Z), a modified base, placed at different, fixed distances from A. The ultrafast ET between these reactants in DNA has been observed with time constants of 5 ps and 75 ps and was found to be essentially independent of the D-A separation (10-17 A). However, the ET efficiency does depend on the D-A distance. The 5-ps decay corresponds to direct ET observed from 7-deazaguanine but not guanine to E. From measurements of orientation anisotropies, we conclude that the slower 75-ps process requires the reorientation of E before ET, similar to E/nucleotide complexes in water. These results reveal the nature of ultrafast ET and its mechanism: in DNA, ET cannot be described as in proteins simply by a phenomenological parameter, beta. Instead, the involvement of the base pairs controls the time scale and the degree of coherent transport.

[Quality of life as a time-dependent covariable in cox regression analysis and its application]

OBJECTIVE

To present a statistical method for combined evaluation of the quality of life and survival time and to study some issues in its application.

METHODS

Based on Cox regression model, quality of life was used as a time-dependent covariable in analysis of the influence factors for the effectiveness of detoxification in 212 drug addicts.

RESULTS

The influence factors entered the regression equation were ways of detoxification for drug abusers, marital status, mode of drug abuse, frequency of detoxification, maternal educational level, maternal occupation, family atmosphere and help and encourage from their relatives and friends, with their hazard ratios of 0.673, 1.315, 1.319, 0.867, 1.120, 1.318, 0.724 and 1.150, respectively.

CONCLUSION

Combined statistical analysis of quality of life and survival time was a better method for the evaluation of the effectiveness of detoxification and its influence factors, which depended mainly on their mother's qualification, family atmosphere, mode and length of drug abuse, etc.

Femtosecond dynamics of the DNA intercalator ethidium and electron transfer with mononucleotides in water

Ethidium (E) is a powerful probe of DNA dynamics and DNA-mediated electron transfer (ET). Molecular dynamical processes, such as solvation and orientation, are important on the time scale of ET. Here, we report studies of the femtosecond and picosecond time-resolved dynamics of E, E with 2'deoxyguanosine triphosphate (GTP) in water, and E with 7-deaza-2'-deoxyguanosine triphosphate (ZTP) in water; E undergoes ET with ZTP but not GTP. These studies elucidate the critical role of relative orientational motions of the donor-acceptor complex on ET processes in solution. For ET from ZTP to E, such motions are in fact the rate-determining step. Our results indicate that these complexes reorient before ET. The time scale for the solvation of E in water is 1 ps, and the orientational relaxation time of E is 70 ps. The impact of orientational and solvation effects on ET between E and mononucleotides must be considered in the application of E as a probe of DNA ET.

[The development and clinical application of a multipurpose neuroendoscope]

The multipurpose rigid neuroendoscope MGE-4 has been developed with the application of the self-focussing lens technology. We have been using it to examine and treat 10 neurosurgical patients who suffered from tumours, hydrocephalus, intracerebral haematomas of head injury and hypertensive cerebral haemorrhage. The short-term effect was satisfactory and there was no operative complications. It is considered that Model MGE-4 with the accessories can be used safely for the brain functional subcortical lesion or the deep-seated cystic lesions and haematomas.

[Progress in the controlled release systems of hirudin]

Hirudin is very effective in treating and preventing cardiovascular disorders. In this review several polymeric controlled release systems of hirudin are introduced. The advantages of the local delivery for restenosis and the feasibility of endovascular drug-containing pharmaceutic stents for local therapy of cardiovascular thrombosis are discussed.

Unexpected frameshifts from gene to expressed protein in a phage-displayed peptide library

A library of long peptides displayed on the pIII protein of filamentous phage was used in biopanning experiments against several protein targets. We find that a large percentage of phage clones that bind specifically to a target contain peptide-encoding genes that do not have an ORF. Instead, the reading frame is either interrupted by one or more nonsuppressed stop codons, or a post-transcriptional frameshift is needed to account for the expression of the minor phage coat protein pIII. The percentage of frameshifted clones varies depending on the target. It can be as high as 90% for clones specific for soluble forms of certain cytokine receptors. Conversely, biopanning against four mAbs did not yield any frameshifted clones. Our studies focused on one clone that binds specifically to rat growth hormone binding protein (GHBP) yet does not have an ORF. A secondary peptide library containing random mutations of this sequence was constructed and panned against GHBP to optimize and correct the reading frame. In the last round (round two) of panning with this library, none of the phage clones that bound to GHBP had an ORF. However, careful analysis of these clones allowed us to design a synthetic peptide capable of binding to GHBP. The results of this study indicate that ORFs are not required to obtain gene expression of the minor coat protein of filamentous phage and suggest that some ORF- clones may have a selective advantage over the clones having ORFs.

[A novel high quality specific antithrombotic drug--hirudin]

Hirudin is the most potent specific inhibitor of thrombin, which is currently undergoing clinical trials as a novel antithrombotic drug. In this paper, the composition and structure, the pharmacological and pharmacokinetic characteristics, the anticoagulant and antithrombotic activity and function, the methods of isolation, recombination and syntheses were reviewed.

[Study on antibiotic rate-limiting barrier membrane by radio-frequency glow discharge plasma deposition]

A method that forming antibiotic rate-controling membrance on surface of polyurethane and ciprofloxacin matrix by RF-GDPD was studied. The surface characterization of film was analysed by XPS. The elution of antibiotic drug in vitro was discussed.

Vascular delay in skeletal muscle: a model for microcirculatory studies

Dynamic myoplasty is a relatively new use for muscle flaps and has led us to revisit the mechanisms of vascular delay as a means of optimizing blood supply to muscle flaps. Despite the well-documented effectiveness of vascular delay in skin flaps, vascular delay in muscle flaps has not been widely reported. Regardless of the many mechanisms postulated in the literature as contributors to the delay effect in skin, the one element common to all these hypotheses is the importance placed on changes in the microcirculation. Based on this factor, in the present study we developed and validated an animal model in which delay-induced microvascular changes could be measured in skeletal muscle flaps. We used the hairless mouse latissimus dorsi muscle flap because its vascular distribution is similar to that of humans and its thin structure will enable us in future studies to directly view and measure its microvasculature using videomicroscopy. In 12 animals, we found that delay significantly (p < 0.01) reduced necrosis of the distal part of the muscle from 57 +/- 9 percent in nondelayed flaps (n = 7) to 22 +/- 3 percent in delayed (n = 5) flaps. In these studies, we also determined that the hairless mouse latissimus dorsi muscle flap will serve as an excellent model for defining microvascular changes throughout delay.

The effect of pioglitazone on hepatic glucose uptake measured with indirect and direct methods in alloxan-induced diabetic dogs

Pioglitazone, a thiazolidinedione derivative, ameliorates hyperglycemia by augmenting peripheral glucose disposal and suppressing hepatic glucose production in diabetic animals. However, the effect of this agent on hepatic glucose uptake has not been explored. To determine this, experiments were conducted in alloxan-induced diabetic dogs with (pioglitazone group, n = 7) or without (control group, n = 5) a 10-day oral treatment with pioglitazone (1 mg x kg(-1) x day(-1)). A euglycemic-hyperinsulinemic (insulin infusion rate 25.2 pmol x kg(-1) x min(-1)) clamp was maintained by adjusting the peripheral glucose infusion rate (GIR). After a 60-min basal period (period I), portal glucose infusion (Pinf, 33.3 micromol x kg(-1) x min(-1)) was administered for 120 min (period II). This was followed by a 60-min recovery period (period III). Arterial insulin levels were kept stable in the supraphysiological range throughout the experiment (1,623 +/- 52, pioglitazone group; 1,712 +/- 52 pmol/l, C group). There was no significant difference in whole-body glucose utilization determined by [3-3H]glucose between the pioglitazone and C groups in period I (68.4 +/- 2.8 vs. 70.1 +/- 2.8 micromol x kg(-1) x min(-1), respectively) and period III (81.2 +/- 5.0 vs. 74.5 +/- 3.3 micromol x kg(-1) x min(-1), respectively). Net hepatic glucose uptake (NHGU) determined by arteriovenous difference method was approximately zero in the basal period (-0.7 +/- 1.1, pioglitazone group; 0.1 +/- 1.2 micromol x kg(-1) x min(-1), C group). In period II, hepatic glucose uptake, determined by the changes in GIR, was significantly higher in the pioglitazone group (6.5 +/- 0.6 micromol x kg(-1) x min(-1)) than in the C group (-0.4 +/- 0.6 micromol x kg(-1) x min(-1), P < 0.001). This observation was also confirmed by NHGU during portal glucose infusion (6.9 +/- 1.4 vs. 2.1 +/- 1.8 micromol x kg(-1) x min(-1), pioglitazone vs. C, respectively; P < 0.025). We conclude that pioglitazone treatment enhances hepatic glucose uptake during portal glucose loading in alloxan-induced diabetic dogs. However, in hyperinsulinemic conditions, pioglitazone does not enhance the already high peripheral glucose uptake.

Changes in binding affinity of a monoclonal antibody to a platelet binding domain of fibrinogen adsorbed to biomaterials

Previously, we found that when fibrinogen-coated polyurethanes resided in a buffer for a period of time (the 'residence time') platelet adhesion to these materials decreased. Other changes in adsorbed fibrinogen such as decreases in polyclonal antibody binding and SDS elutability supported the conclusion that fibrinogen undergoes postadsorptive conformational changes. Subsequently we measured the binding of monoclonal antibodies to the three putative platelet binding sites on fibrinogen, using a single mid-range concentration of antibody. We found that binding of a monoclonal antibody to the platelet binding site at the C-terminus of the gamma chain of fibrinogen changed little with residence time, while binding of monoclonal antibodies to the other two putative binding sites on fibrinogen either increased with residence time (RGDF at A alpha 95-98), or first increased and then decreased with residence time (RGDS at A alpha 572-575). In the current study, we measured antibody binding affinity, Ka, by measuring antibody binding at a series of antibody concentrations. This is a more sensitive method for detecting changes in adsorbed fibrinogen than measuring antibody binding from a single antibody concentration. The Ka was determined for two antibodies, M1 (4A5), which binds to a platelet binding domain of fibrinogen (gamma 402-411) and R1 (155 B 1616), which binds to residues 87-100 of the A alpha chain (containing an RGDF site). A summary of the results for the M1 antibody are as follows. The Ka was higher for M1 binding to fibrinogen adsorbed to Immulon I than to Biomer, Biospan or poly(ethylene terephthalate), suggesting that fibrinogen adsorbed to Immulon I is more platelet adhesive than fibrinogen adsorbed to the other polymers. On Biospan, the Ka decreased from 2.8 x 10(9) to 1.0 x 10(9) M-1 after a 24 h 37 degrees C residence time, which correlated with the decrease in platelet adhesiveness of adsorbed fibrinogen observed previously under these conditions. The change in Ka was greater when adsorbed fibrinogen was kept under denaturing conditions. For example, the Ka decreased from 2.8 x 10(9) to 0.8 x 10(9) M-1 after a 1 h 70 degrees C residence time whereas it remained approximately the same, 2.9 x 10(9) M-1, after a 24 h 0 degree C residence time.

[A legionella pneumophila strain serologically cross-reacting with thirteen serogroups of this species]

A bacterial strain, designated as Jin-1, was isolated from a water sample taken from the Jinyang Lake located in the suburbs of Taiyuan City, Shanxi Province. Its morphologic and tinctorial properties, nutritional requirements, growth characteristics, biochemical reactions, as well as results of DNA and peptide analysis overall met the criteria for identification of Legionella pneumophila. In serogrouping, extensive cross-reactions between Jin-1 and the type strains of L. pneumophila serogroup 1 through 14 were observed in both slide and tube agglutination tests mediated by the IgM antibodies. However, Jin-1 revealed the L. pneumophila serogroup 5 specificity in IFA, ELISA and dot-ELISA, all mediated by the IgG antibodies. Jin-1 was finally identified as a strain of L. pneumophila serogroup 5 with the more complex antigenic composition than the ATCC type strain of this serogroup. The taxonomic conclusion has been confirmed by CDC. A Legionella pneumophila strain which serologically cross-reacting with so many serogroups of this species has never been reported in the published articles. It is presumed that the cross-reacting antigen of Jin-1 belongs to the thymus-independent antigen by nature.

[Role of biological clocks in normal conditions, pathology, and in therapy. 2. Clinical chronoradiotherapy of lung cancer]

The present study tests whether body core temperature can serve as a marker rhythm for guiding the timing of the radiotherapy of lung cancer. It was shown that the treatment by radiation at the time of peak core temperature has more effectively then treatment at other circadian stages here investigated.

[The role of biological clocks in formation of standards, pathology, and in therapy. 1. Chronobiological aspects of formation of blood pressure in children with positive and negative family history of relatively high blood pressure]

There are a difference in average values and in amplitudes of about-7 and monthly rhythms of infants' blood pressure with positive and negative family history to the hypertension. Chronobiological approach to these problem can reveal hypertension risk at the early stage of life.

Comparison of personality traits of only and sibling school children in Beijing

The number of only children in China has increased rapidly since the late 1970s, when the Chinese government advocated the "one-child-per-family" policy. This increase has caused much public concern about the healthy growth of the young generation. In this study the behavioral traits of Chinese, urban, only children were investigated. The participants were 444 children with siblings and 473 only children from Grades 1, 3, and 5 in Beijing primary schools. An inventory consisting of 27 items covering three behavioral traits was developed. The children were rated on the inventory by the principal teacher of the class. Factor analysis revealed three main factors: achievement motivation, interpersonal skills, and attitude toward manual labor. The only children exceeded the sibling children on achievement motivation. No differences were found between only children and sibling children on interpersonal skills and attitude toward manual labor. Gender differences were evident; girls consistently received higher ratings on achievement motivation and interpersonal skills. The possible underlying reasons for these differences are discussed.

Reorientations in the bacteriorhodopsin photocycle

Reversible photoinduced reorientations of bacteriorhodopsin have been detected in suspensions of the purple membrane of Halobacterium salinarium. The anisotropy in bacteriorhodopsin during the nanosecond through millisecond stages of the photocycle was measured by time-resolved linear dichroism and transient absorption measurements. From these measurements the anisotropies of the K, L, M, and O intermediates were determined and related to the chromophore orientation with respect to the initially selected orientation. The anisotropies of the K and L states are 0.38 +/- 0.01 and 0.35 +/- 0.01, respectively. Further anisotropy decay after formation of the M intermediate in about 0.5 ms is evidence of orientational motion at this stage in the photocycle. A constant anisotropy with a value of 0.39 +/- 0.02 in the O intermediate demonstrates a recovery of the initial protein orientation with the formation of the O state. These results demonstrate that reorientations in BR are photoinduced and reversible. Similar measurements for L and M were carried out for purple membrane in polyacrylamide gels, where the anisotropies in the L and M states are 0.38 +/- 0.014 and 0.36 +/- 0.01, respectively. These results show that reorientations also occur in BR immobilized in gels. Anisotropy decay in the M state after formation of the M intermediate was not detected in the gels, in contrast to the M intermediate in suspensions. Orientational changes are observed for BR in purple membrane suspensions in the K state, during the K-->L step, in the M state possibly related to an M1-->M2 transition, and in the O state, where an almost complete return to the original orientation occurs.(ABSTRACT TRUNCATED AT 250 WORDS)

[Studies on the detection of Legionella pneumophila by the application of polymerase chain reaction (PCR)]

DNA fragment of Legionella pneumophila, the PCR was performed with a pair of artificial synthesized primer. Results of agarose electrophoresis and EB staining showed that there was a 870 bp band shared by serogroups 1-14 of L.pneumophila. The sensitivity of PCR in detecting Legionella from water was 350cfu/ml, however, the specific DNA probe labeled with 32P was .43cfu/ml by blot hybridization. The positive rate of tissue specimens from infected guinea-pigs with Legionella pneumophila was 83.3% by PCR detection, and only 26.6% by bacteriological culture method. An outbeak caused by Lp10 was verified by PCR. The result showed that the PCR could detect the infection of Legionella rapidly, specifically and sensitively.