[The prevalence of hypertension, diabetes mellitus and hyperlipemia among 1369 subjects for physical examination in Changsha]

A survey of the prevalence of hypertension (HT) and diabetes mellitus (DM) and hyperlipemia (HL) was conducted among 1369 subjects for health check in Changsha. The results showed that the prevalence of HT and DM and impaired glucose tolerance (IGT) and HL were 17.2% and 4.6% and 5.9% and 27.4%, respectively. The prevalence of HT and DM and IGT increased with age. The higher the body mass index was, the higher the prevalence of HT and DM and HL was. These findings indicate that the aging and over weight are important risk factors to the prevalence of HT, DM and HL.

[Sequence analysis of human immunodeficiency virus type 1 tat gene among the long-term HIV infected non-progressoris in Yunnan province]

OBJECTIVE

HIV-1 tat gene is one of its regulatory genes necessary for its replication. This study is to explore whether the variation of tat gene influences the AIDS progress of HIV infected individual.

METHODS

We carried out investigation on tat gene of HIV among the long term HIV infected non-progressors and the commonly infected individuals. Mononuclear cells of peripheral blood were isolated and cellular DNA was extracted. Nested PCR method was used to amplify tat gene and their sequences were analyzed.

RESULTS

Blood were collected from 22 HIV infected individuals, of which 11 cases were infected with B subtype strains based on previous env gene analysis and belonged to long term non-progressors according to clinical features and immunology. The other 11 cases were common HIV infection of which 5 subtype B and 6 subtype C were found. Both long term non-progressor group (subtype B) and the commonly HIV infectedly group (subtype B) had constantly four amino acids different from that of international B subtype consensus sequence The both groups clustered randomly on the phylogenetic tree. In commonly HIV infected subtype C group there were 6 amino acids different from that of international subtype C. The variation inside the tatgene of common subtype C group was small.

CONCLUSIONS

There was no regular variation and significant difference between long term HIV infected non-progressive group and commonly HIV infected subtype B group. There is no evidence showing that progressive speed of AIDS correlated with the tat sequence profile of HIV-1.

[Determination of lignan glycosides in the roots of Gaultheria yunnanensis Rehd. by HPLC]

OBJECTIVE

To determine the contents of four lignan glycosides in the root of Gaultheria yunnanensis, namely, D1: gaultheroside A, D2:(-)-8'-methoxyisolariciresinol-2a-O-beta-D-xylopyranoside, D3:(-)-isolariciresinol-2a-O-beta-D-xylopyranside, D4:(+)-lyoniresinol-2a-O-beta-D-glucoxylopyranoside.

METHOD

Rp-HPLC was used to separate and analyze the lignan glycosides in the root of the title plant.

RESULT

The method for sample preparation was set up; the gradient program for the mobile phase was established; and the retention times of four lignan glycosides were determined.

CONCLUSION

The method has been proved to be accurate, reproducible and of higher recovery rate.

[Effect of three composite recipes on content of monoamine transmitters in hypothalamus induced by intracerebroventricular injection of interleukin-1 of rats]

OBJECTIVE

To explore the different effects of Youguiyin decoction, Sijunzi decoction, Taohong Siwu decoction on the content of monoamine transmitters in the hypothalamus induced by cytokines.

METHODS

A reactive status of hypothalamic monoamine transmitters to cytokine in rat was built by observing the content change of monoamine transmitters in hypothalamic homogenate after intracerebroventricular (icv) injection of human recombinant interleukin-1 beta(IL-1 beta). On this basis, the different effect of three composite recipes on this status was observed.

RESULTS

The content of norepinephrine (NE) declined significantly compared with control group after icv injection of IL-1. Compared with IL-1 group, Youguiyin further reduced the content of NE induced by icv injection of IL-1, while Taohong Siwu decoction and Sijunzi decoction did not show any effect on this status.

CONCLUSIONS

It seems that Youguiyin for tonifying Kidney could increase the reactivity of hypothalamic NE neuron, Sijunzi decoction for invigorating Spleen and Taohong Siwu decoction for promoting blood circulation did not show this effect.

Parathyroid hormone deficiency and excess: similar effects on trabecular bone but differing effects on cortical bone

Parathyroid hormone (PTH) may be anabolic at trabecular bone and catabolic in cortical bone. As many regions of the skeleton contain both types of bone, the effects of PTH deficiency or excess may be difficult to evaluate using bone densitometry, a technique that integrates the cortical and trabecular compartments of bone. We asked the following questions: 1) Is the higher bone mineral density (BMD) in postsurgical hypoparathyroidism due to higher cortical, not trabecular, bone? 2) Is age-related bone loss slowed in patients with postsurgical hypoparathyroidism? 3) Is lower BMD in primary hyperparathyroidism the result of deficits in cortical, not trabecular, bone? BMD of the lumbar spine, proximal femur, distal radius, and femoral midshaft was measured by postero-anterior (PA) scanning, while bone mineral content (BMC) of the third lumbar vertebra was measured by lateral scanning using dual x-ray absorptiometry in 10 women, ages 64.6 +/- 3.2 yr, with postsurgical hypoparathyroidism and in 25 women, ages 68.7 +/- 1.6 yr, with primary hyperparathyroidism. Measurements were repeated 4.7 +/- 0.6 yr later in 8 patients with hypoparathyroidism and 4.0 +/- 0.4 yr later in 20 age-matched controls. Data were expressed as z scores (SD, mean +/- sem) derived from 405 postmenopausal women. In patients with hypoparathyroidism, bone mass z score of the third lumbar vertebra (vertebral body plus posterior processes) was higher than zero by PA scanning (1.26 +/- 0.58 SD, P < 0.05) and lateral scanning (1.04 +/- 0.60 SD, P = 0.1), and higher at the trabecular-rich vertebral body (1.02 +/- 0.47 SD, P = 0.07) and predominantly cortical posterior processes (0.98 +/- 0.66 SD, P = 0.1) determined by lateral scanning. The BMD z scores were higher than zero at the femoral neck (0.89 +/- 0.48 SD, P = 0.09), but not at the femoral midshaft (0.45 +/- 0.60, NS) and distal radius (0.04 +/- 0.51, NS). During follow-up, femoral neck BMD decreased in controls but not in patients with hypoparathyroidism (slope, -0.00818 +/- 0.00496 g/cm2/year vs. 0.00907 +/- 0.00583 g/cm2/year, respectively, P = 0.06). There was no change in lumbar spine BMD in either group. In 25 women with primary hyperparathyroidism, there were no deficits in BMD at the third lumbar vertebra (vertebral body plus posterior processes) by PA or lateral scanning. By lateral scanning, BMC was increased at the vertebral body (0.64 +/- 0.31 SD, P < 0.01) and reduced at the posterior processes (-0.65 +/- 0.26 SD, P < 0.05). BMD was lower at the midshaft of the femur (-0.82 +/- 0.37 SD, P < 0.05) and at the distal radius (-0.68 +/- 0.20 SD, P < 0.01), but not at the femoral neck (-0.08 +/- 0.20 SD, NS). Longitudinal data were unavailable in hyperparathyroid patients. In summary, trabecular bone is increased by both PTH deficiency and excess. Cortical bone loss is slowed by PTH deficiency and accelerated by PTH excess so that suppression of PTH may reduce age-related bone loss and the risk of fracture. Assessment of BMD in PTH deficiency and excess requires the separate study of cortical and trabecular bone.

Is there a risk of cytomegalovirus transmission during in vitro fertilization with donated oocytes?

OBJECTIVE

To define the risk of human cytomegalovirus (HCMV) transmission from donated oocytes.

DESIGN

Prospective study.

SETTING

University IVF program.

PATIENT(S)

Sixty-seven couples undergoing 72 cycles of IVF-ET.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Serum from both partners (women: n = 71; men: n = 60) was obtained for detection of antibodies to HCMV. Semen before preparation (n = 53), sperm after preparation (Percoll gradient; n = 47), cervical mucus aspirated at the time of oocyte aspiration (n = 70), and uninseminated oocytes and embryos not suitable for cryopreservation (n = 568) were frozen in liquid nitrogen. Polymerase chain reaction was used for detection of HCMV (immediate early 1 gene) in all samples collected.

RESULT(S)

Serum antibodies to HCMV were found in 62% of the women and 37% of the men tested. Human cytomegalovirus DNA was detected in 25% of the ejaculates and in 19% of the cervical mucus samples. There was no amplification of HCMV DNA from oocytes or embryos.

CONCLUSION(S)

Because we were unable to amplify HCMV DNA from any of the oocytes or embryos, it seems unlikely that HCMV is transmissible through oocyte or embryo donation.

[Analysis of renal function on 1,743 people of different ages]

OBJECTIVE

To understand and evaluate the currency and correlation between parameters about renal function.

METHODS

We divided 1,743 people whose ages vary from 20-85 years into six groups(A, B, C, D, E, F). Urinary Mini Albumin, RBP, NAG, osmotic pressure, serum BUN, plasma UA and internal creatinine clearance were measured as parameter about renal function.

RESULTS

There was no obvious difference between the Group A and Group B(P > 0.05); The mean value of urinary NAG and urinary RBP in the two group was 10.9650 +/- 6.5650 and 0.1885 +/- 0.4709; However, when they were compared with the values of C, D, E group respectively, there were prominent differences (P < 0.05 or P < 0.01). Urinary Alb value of Group A is quite different from other groups. No difference exists between urinary Alb value of Group E and Group F(P > 0.05). Internal creatinine clearance decrease by the rate of 8.5%, 17.8%, 29.9%, 42.9% and 56.3% when Groups B, C, D, E and F was compared with Group A; while urinary osmotic pressure and the value of plasma BUN, Cr and UA has no obvious difference between any two groups(P > 0.05).

CONCLUSION

The clearance of internal creatinine decrease with the growing of the age, especially older than 50 years of age. The parameter about tubular injury increase obviously after 40 years old though it does not change prominently before 50 years old, while it tends to be stable after 70 years old. We think it is during period of 40 to 70 years old that the renal function decreases more rapidly.

Polymorphism of the vitamin D receptor gene and corticosteroid-related osteoporosis

Corticosteroid therapy (CST) is associated with reduced intestinal calcium absorption, bone loss and increased fracture risk. As polymorphisms of the vitamin D receptor (VDR) gene may be associated with bone mineral density (BMD) and intestinal calcium absorption, we asked whether patients with a given VDR genotype receiving CST may be at increased or decreased risk for corticosteroid-related bone loss and osteoporosis. We measured areal BMD (g/cm2) by dual-energy X-ray absorptiometry in 193 women (50 premenopausal, 143 postmenopausal) and 70 men with rheumatoid arthritis (n = 44), obstructive airway diseases (n = 128) and other corticosteroid-treated diseases (n = 91). All patients received a cumulative dose greater than 1.8 g per year or a minimum of 5 mg daily of prednisolone or equivalent for at least 1 year. VDR alleles were typed by polymerase chain reaction assay based on the polymorphic BsmI and TaqI restriction sites. BMD in patients was expressed as a Z-score (mean +/- SEM) derived from age- and gender-matched controls. BMD was reduced in patients at the lumbar spine (bb, -0.52 +/- 0.12; Bb, -0.47 +/- 0.11; BB, -0.65 +/- 0.18 SD; p < 0.01), femoral neck (bb, -0.46 +/- 0.10; Bb, -0.34 +/- 0.10; BB, -0.54 +/- 0.14 SD; p < 0.01), Ward's triangle (bb, -0.44 +/- 0.10; Bb, -0.31 +/- 0.10; BB, -0.45 +/- 0.13 SD; p < 0.01), and trochanter (bb, -0.50 +/- 0.10; Bb, -0.30 +/- 0.10; BB, -0.44 +/- 0.14 SD; p < 0.01). However, there was no significant difference in the deficit in BMD in any of the genotypes, either before or after adjusting for age, sex, body mass index, disease type, age at onset of disease, disease duration, cumulative steroid dosage, smoking status and dietary calcium intake. Similarly, there were no detectable differences between the BsmI genotypes and the rate of bone loss in 79 patients with repeated BMD measurements at an interval of 4-48 months. The data suggest that the VDR genotypes may not be a means of identifying patients at greater risk of corticosteroid-related bone loss.

Expression and functional analysis of a hemopoietic progenitor antigen, NJ-1 (114/A10), in the megakaryocytic lineage

To analyze the functions of molecules expressed in hemopoietic progenitor cells, we obtained several monoclonal antibodies by immunizing Wistar rats with antigens from a murine immature leukemic cell line, DA-1. Here, we characterize one antibody designated NJ-1, which recognizes a 145-kd molecule, and identify the cDNA encoding the NJ-1 antigen by retrovirus-mediated expression cloning. Sequence analysis of the cDNA reveals that it is identical to a previously reported cDNA encoding a surface molecule of 573 amino acids recognized by monoclonal antibody 114/A10. Our studies show that expression of NJ-1 antigen is upregulated in a murine megakaryoblastic cell line, L8057, when it differentiates into a megakaryocytic lineage in response to 12-O-tetradecanoyl phorbol-13-acetate. Overexpression of NJ-1 antigen in L8057 cells inhibits cell adhesion to fibronectin, suggesting that it may act as a negative regulator of cell adhesion in the megakaryocytic lineage.

Pathways to a protein folding intermediate observed in a 1-microsecond simulation in aqueous solution

An implementation of classical molecular dynamics on parallel computers of increased efficiency has enabled a simulation of protein folding with explicit representation of water for 1 microsecond, about two orders of magnitude longer than the longest simulation of a protein in water reported to date. Starting with an unfolded state of villin headpiece subdomain, hydrophobic collapse and helix formation occur in an initial phase, followed by conformational readjustments. A marginally stable state, which has a lifetime of about 150 nanoseconds, a favorable solvation free energy, and shows significant resemblance to the native structure, is observed; two pathways to this state have been found.

[Ultrasonographic diagnosis of peripartum cardiomyopathy]

OBJECTIVE

Analysing the characteristics of ultrasonographic manifestation for peripartum cardiomyopathy (PPCM), and discussing its diagnostic criteria.

METHOD

Echocardiographic examination in 20 PPCM and 20 normal volunteers (NC) was completed with Acuson 128 computed sonography.

RESULTS

All 20 PPCM showed an enlargement in the left ventricle and left atrium. Left ventricular end diastolic anterio-posterior diameter was 65.4 +/- 4.5 mm, left atrium end systolic anterio-posterior diameter was 43.1 +/- 6.1 mm. There was a very significant difference in left atrium and ventricle size between PPCM and NC (P < 0.001). Among 20 PPCM, there were enlargements of the right atrium in 6 cases, of the right ventricle in 8 cases and 20% cardiomegaly. All patients showed decreased left ventricular wall movement. Ejection fraction (0.33 +/- 0.08) and fraction shorting (16.2 +/- 5.0%) were significant different with that of NC (P < 0.001). The regurgitation rate in the heart valvae was MR 100%, TR 70%, PR 70% and AR 15% respectively.

CONCLUSION

The ultrasonographic manifestation of PPCM was not specific, so the diagnosis of PPCM depended on peripartum history, left atrium and ventricle enlargements or cardiomegaly, decreased left ventricular function based on ruling out of other heart diseases.

The early stage of folding of villin headpiece subdomain observed in a 200-nanosecond fully solvated molecular dynamics simulation

A new approach in implementing classical molecular dynamics simulation for parallel computers has enabled a simulation to be carried out on a protein with explicit representation of water an order of magnitude longer than previously reported and will soon enable such simulations to be carried into the microsecond time range. We have used this approach to study the folding of the villin headpiece subdomain, a 36-residue small protein consisting of three helices, from an unfolded structure to a molten globule state, which has a number of features of the native structure. The time development of the solvation free energy, the radius of gyration, and the mainchain rms difference from the native NMR structure showed that the process can be seen as a 60-nsec "burst" phase followed by a slow "conformational readjustment" phase. We found that the burial of the hydrophobic surface dominated the early phase of the folding process and appeared to be the primary driving force of the reduction in the radius of gyration in that phase.

[Raman spectrum characteristics of methane]

Two characteristic Raman peaks of methane at 2917 and 3020cm(-1) were measured. The results show that the four C-H bonds of methane molecular are unequal. The assignment of Raman bands at 2917 and 3020cm(-1) was discussed in this paper.

[Studies on the general properties of a novel microwave plasma enhanced glow discharge source]

This paper introduced a novel microwave plasma enhanced glow descharge source, the structure design and operation were decribed, and the mutual effects of the main characters, such as pressure, current, voltage, microwave power and sputtering rates were also investigated in details.

Engineering of plasmin-resistant forms of streptokinase and their production in Bacillus subtilis: streptokinase with longer functional half-life

The short in vivo half-life of streptokinase limits its efficacy as an efficient blood clot-dissolving agent. During the clot-dissolving process, streptokinase is processed to smaller intermediates by plasmin. Two of the major processing sites are Lys59 and Lys386. We engineered two versions of streptokinase with either one of the lysine residues changed to glutamine and a third version with both mutations. These mutant streptokinase proteins (muteins) were produced by secretion with the protease-deficient Bacillus subtilis WB600 as the host. The purified muteins retained comparable kinetics parameters in plasminogen activation and showed different degrees of resistance to plasmin depending on the nature of the mutation. Muteins with double mutations had half-lives that were extended 21-fold when assayed in a 1:1 molar ratio with plasminogen in vitro and showed better plasminogen activation activity with time in the radial caseinolysis assay. This study indicates that plasmin-mediated processing leads to the inactivation of streptokinase and is not required to convert streptokinase to its active form. Plasmin-resistant forms of streptokinase can be engineered without affecting their activity, and blockage of the N-terminal cleavage site is essential to generate engineered streptokinase with a longer in vitro functional half-life.

Control of the amount of free molecular iodine in iodine germicides

Horseradish peroxidase has been used to generate iodine compositions that comprised principally free molecular iodine. The concentration of free molecular iodine in these enzyme-based compositions ranged from 44 to 63% of the thiosulphate titratable iodine; this is substantially higher than the corresponding value for the povidone-iodine preparation betadine. The biocidal efficacy of these compositions was proportional to the concentration of free molecular iodine. Iodine compositions with relatively low total iodine concentrations but high levels of free molecular iodine (20-175 ppm) killed Staphylococcus aureus and spores of Bacillus subtilis more rapidly than betadine. The effects of normal saline and these enzyme-based iodine compositions on the rate of epidermal regeneration in superficial swine wounds were comparable. These results suggest that an effective germicide containing a high level of molecular iodine need not be irritating or toxic.

The benefit of hormone replacement therapy on bone mass is greater at the vertebral body than posterior processes or proximal femur

The aim of this study was to determine whether the higher vertebral bone mass in women receiving hormone replacement therapy (HRT) is confined to the trabecular rich vertebral body rather than the predominantly cortical posterior processes, and to determine whether the protective effect of HRT at the proximal femur, a predominantly cortical site, is less than at the spine. Bone mass (g) of the third lumbar vertebra (total, vertebral body and posterior processes, measured by lateral scanning), and bone mineral density (g/cm2) of the femoral neck, Ward's triangle, and trochanter were measured using dual X-ray absorptiometry in a cross-sectional study of 71 women receiving HRT for 5.7 +/- 0.4 years (mean +/- SEM), ranging from 1 to 21 years, 69 age-matched controls, and 42 premenopausal controls aged 20 to 40 years. Relative to untreated postmenopausal controls, total bone mass of the third lumbar vertebra (body plus posterior processes) by postero-anterior (PA) scanning was 0.4 +/- 0.1 SD or 9.6 +/- 3.0% higher in HRT treated women (p < 0.01). By lateral scanning, total bone mass was higher than age-matched controls (z score 0.4 +/- 0.1 SD or 11.2 +/- 3.4%, p < 0.01). This difference was confined to the vertebral body (z score 0.6 +/- 0.1 SD, p < 0.001), which was 17.1 +/- 3.3% higher than in age-matched controls (p < 0.001). Bone mass of the posterior processes was no higher [z score 0.1 +/- 0.1, not significant (NS)]. The deficit at the vertebral body in HRT-treated women, relative to premenopausal controls, was half the deficit at the vertebral body in untreated postmenopausal women (t score -0.7 +/- 0.1 vs. -1.4 +/- 0.1 SD, respectively; p < 0.001) but no less at the posterior processes (t score -1.6 +/- 0.2 vs. -1.9 +/- 0.2 SD, respectively; NS). Similarly, the deficit in the vertebral body in the HRT treated group was half the deficit at their posterior processes (t score -0.7 +/- 0.1 SD vs. -1.6 +/- 0.2, respectively; p < 0.001). In HRT-treated women, bone mass diminished significantly with age at the posterior processes (r = -0.31, p < 0.01), but not at the vertebral body (r = -0.21, p = 0.07). Bone mass diminished significantly with age at the vertebral body and posterior processes in untreated women (r = -0.55, p < 0.001; r = -0.45, p < 0.001, respectively). Bone density (g/cm2) diminished at all femoral sites with advancing age in HRT-treated women. A protective effect was seen at the femoral neck and Ward's triangle, but not trochanter (z score 0.2 +/- 0.1, p = 0.06; 0.3 +/- 0.1, p < 0.05; 0.0 +/- 0.1, NS, respectively). In conclusion, the protective effect of HRT against bone loss at the vertebral body, the site of fracture in osteoporosis, may be underestimated by PA scanning. The greater benefit at the vertebral body, and more modest effect at the proximal femur, suggests that HRT may be a more effective means of reducing the risk of spine than hip fractures.

Molecular dynamics simulation study of DNA dodecamer d(CGCGAATTCGCG) in solution: conformation and hydration

A molecular dynamics simulation of the dodecamer duplex d(CGCGAATTCGCG) using the particle mesh Ewald sum assumed a B-conformation remarkably close to the observed X-ray structure. The Ewald summation method effectively eliminates the usual "cut-off" of long-range interactions and allowed us to evaluate the full effect of the electrostatic forces. This simulation showed remarkable agreement with the Dickerson X-ray structure in both average structure and B-factors; within the EcoRI site itself, the rms deviation between the average theoretical and observed structures was 1.1 A. The width of the minor groove fluctuated between a wide and narrow configuration with the latter corresponding closely to the X-ray structure. The simulation also suggested a strong sequence-dependent signature on the minor groove width in both wide and narrow conformers. Hydration shells in both the major and minor grooves were observed. The "spine of hydration" in the minor groove was clear. In the major groove the first hydration shell appears to be a ribbon-like structure that reproduces the principal features of observed X-ray structures; subtle variations of this hydration pattern suggest sequence dependencies. Sequence-dependent features were also examined for helical and other geometric parameters. The successful reproduction of many experimentally observed fine structural features shows that the Ewald summation significantly improves the fidelity of the calculations.

[Changes in t-PA, PAI-1 gene expression of coronary arteries with preconditioning in acute myocardial infarction rat]

The changes of t-PA, PAI-1 gene expression and t-PA activity were investigated in coronary arteries of Acute Myocardial Infarction (AMI) rat by nucleic acid molecular hybridization and spectrophotometric assay. The effect of preconditioning on t-PA and PAI-1 was observed in this model. The results indicated that: (1) Tissue t-PA activity in ischemia was significantly decreased than that in control (P < 0.01). t-PA activity was obviously increased in preconditioning group (P < 0.01 compared with ischemia group). (2) t-PA and PAI-1 mRNA expression in ischemia were higher than that in control, especially PAI-1 4.6 times higher than that in control), while PAI-1 expression lower in preconditioning rat. (3) In situ hybridization showed t-PA and PAI-1 were primarily expressed by endothelial cells in vessels of rat heart. These data suggested that abnormal expression of PAI-1 and t-PA was involved in AMI. This fibrinolytic depress was associated with high PAI-1 expression. Preconditioning may be effective to protect myocardium through decreasing PAI-1 mRNA expression.

Preliminary study of the effects of metoprolol and propafenone on ventricular arrhythmia with positive ventricular late potential

OBJECTIVE

To compare the effects of metoprolol and propafenone in patients with ventricular arrhythmia (VA) of positive ventricular late potential (VLP) and to discuss the effect of medicine on high risk VA.

METHODS

30 A total of 128 patients (78 males and 50 females) with VA of positive VLP were randomly divided into 3 groups. Groups A and B were given metoprolol and propafenone respectively, group C was given vitamin C as placebo. Twenty-four hours dynamic electrocardiogram and VLP were examined before treatment and 4 weeks after treatment.

RESULTS

Propafenone could effectively control VA but could not reverse positive VLP to negative meanwhile it had proarrhythmia effect (2/40), metoprolol could effectively control VA (38/46) and reverse positive VLP to negative (39/46) with no obvious side effects. The dosage from 50 to 100 mg/day made no difference. VA and VLP had no significant changes in group C.

CONCLUSIONS

Metoprolol is superior to other medicine for VA of positive VLP when the patients have no contraindication of preceptor blocking agents.

[Studies on the spectral characteristics of argon in a novel microwave plasma enhanced glow discharge source]

This paper describes a investigation about the spectral characteristics of argon in a novel microwave plasma enhanced glow discharge source. In different discharge conditions, such as glow discharge, microwave plasma and microwave plasma enhanced glow discharge, there are different distributions of argon spectral lines.

[Subtype and sequence analysis of the C2-V3 region of gp120 genes among human immunodeficiency virus infected IDUs in Ruili epidemic area of Yunnan Province of China]

DNA fragments of HIV-1 env gene were amplified by nested-PCR from 17 uncultured peripheral blood mononuclear cells (PBMCs) obtained from HIV-1 seropositive intravenous drug users (IDUs) in Ruili city of Yunnan Province. The C2-V3 region (about 450 bp) of them were sequenced. Sequence analysis showed that there exists two HIV-1 subtypes, B and C, with 5.8% and 2.2% gene divergence inside each subtype. The 12 subtype B strains, were closely related to those found in Thailand, Myanma and Ruili city of Yunnan, and the nucleotide sequence divergence between them ranged from 4.4% to 4.9%; meanwhile, the 5 subtype C strains were most close to those found in India as well as Ruili city, all with a genetic distance of 1.9%. The small divergence among Ruili HIV-1 subtype C strains suggests a recent epidemic. The analysis of V3 loop amino sequence of 12 subtype B HIV-1 reveals that V3-tip motif of 6 samples (50%) is GPGQ and that of 3 samples (25%) is GPGR. In addition, the codon of arginine (R) of all the strains is CGA instead of AGA. This result is in accordance with our previous hypothesis that there is a drift in vivo from GPGR to GPGQ motif on the tipof V3-loop of HIV-1 subtype B strain in this arm with the elapse of time.

Dynamic contributions to the DNA binding entropy of the EcoRI and EcoRV restriction endonucleases

Molecular Dynamics simulations on DNA-EcoRI and DNA-EcoRV complexes suggest that the DNA within these complexes is significantly more ordered than free DNA. Similarly, both the protein and the DNA are more ordered in the specific (cognate) DNA-EcoRV complex than they are in the non-cognate DNA-protein complex, consistent with recently proposed analogies between protein folding and sequence-specific DNA-protein recognition. Analysis of the trajectories shows that the net entropy gain upon specific binding to be the result of opposing contributions. Solvent release, which increases entropy versus configurational terms (as measured by the magnitude of the atomic fluctuations), and collective terms from tight coupling between the motions of the protein and the DNA.