OxLDL upregulates growth-regulation oncogene alpha expression in human endothelial cells

OBJECTIVE

To explore the effect of oxLDL on CXC chemokine growth-regulated oncogene alpha (GRO alpha) expression in human endothelial cells and the possible functional significance of the effect.

METHODS

LDL was isolated by sequential ultracentrifugation and oxidized to oxLDL. Reverse transcription-polymerase chain reaction with GAPDH as internal standard was applied and CXC chemokine GRO alpha mRNA in endothelial ECV304 cells was examined. ELISA was used to determine GRO alpha protein expression on ECV304 cells surface and in the medium. With static cell adhesion assays, the physiological significance of elevated GRO alpha expression was tested.

RESULTS

OxLDL, not LDL, treatment of ECV304 cells significantly induced the expression of GRO alpha mRNA that was not detectable in untreated cells. Induction of expression was first evident at 1 h, became maximal at 2 h, and was substantially decreased by 4 h. In a concentration- and time-dependent manner, oxLDL, and not LDL, induced a significant upregulation of GRO alpha surface expression in ECV304 cells that was at a barely detectable level in unstimulated ECV304 cells. GRO alpha protein in the medium did not change significantly. Exposure of ECV304 cells to 40 micrograms protein/ml oxLDL for 24 h resulted in a marked increase in the number of U937 cells bound to ECV304 cells and antibodies to GRO alpha inhibited adhesion.

CONCLUSION

OxLDL functionally upregulated GRO alpha expression in endothelial cells.

[Study on high-efficiency gene transfer of pseudotyped HIV vector]

OBJECTIVE

To investigate the high-efficiency of pseudotyped HIV as gene transfer vector.

METHODS

Three plasmids of pseudotyped HIV gene transfer vector system were transferred into packaging cell line 293T by Ca3 (PO4)2 precipitation method. GFP (Green Fluorescence Protein) or HSV-tk gene was constructed in the plasmid pHR'CS respectively (pHR'CS.GFP or pHR'CS.HSV-tk). The pseudotyped HIV particles were observed through electronic microscopy and were measured through spectrofluorophotometer. High titer pseudotyped HIV was harvested from volume of virus-producing cell supernatant and concentrated. Ovarian epithelial cancer cell line SKOV3 and normal human gingival fibroblast cell GF were infected by pseudotyped HIV. PCR and RT-PCR were resorted to demonstrate the successful transduction and transcription of the HSV-tk gene. After administration of GCV, the changes of those cells and apoptosis were observed through optical microscopy. The cytotoxicity efficacy of HSV-tk/GCV system was evaluated by MTT method. The growth inhibition rate (GIR) of cells and inhibition concentration 50 (IC50) were counted.

RESULTS

The above plasmids were effectively transferred into 293T cell. A lot of pseudotyped HIV particles were observed through electronic microscopy. The virus supernatant had a high absorbing value at 510 nm through spectrofluorophotometer, which proved the existence of virus. After pseudotyped HIV infection, SKOV3 and GF had remarkable infection rate. 600 bp strand was seen through PCR and RT-PCR. Changes and apoptosis of cells followed by administration of GCV were observed. The MTT method showed that the cytotoxicity efficacy of GCV was high to SKOV3 and GF cell.

CONCLUSIONS

The pseudotyped HIV is a high-efficiency gene transfer vector.

Investigation of the role of the domain linkers in separate site catalysis by Clostridium symbiosum pyruvate phosphate dikinase

Pyruvate phosphate dikinase (PPDK) catalyzes the reversible reaction: ATP + P(i) + pyruvate <--> AMP + PP(i) + PEP using Mg2+ and NH4+ ions as cofactors. The reaction takes place in three steps, each mediated by a carrier histidine residue located on the surface of the central domain of this three-domain enzyme: (1) E-His + ATP <--> E-His-PP.AMP, (2) E-His-PP.AMP + P(i) <--> E-His-P + AMP + PP(i), (3) E-His-P + pyruvate <--> E-His + PEP. The first two partial reactions are catalyzed at an active site located on the N-terminal domain, and the third partial reaction is catalyzed at an active site located on the C-terminal domain. For catalytic turnover, the central domain travels from one terminal domain to the other. The goal of this work is to determine whether the two connecting linkers direct the movement of the central domain between active sites during catalytic turnover. The X-ray crystal structure of the enzyme suggests interaction between the two linkers that may result in their coordinated movement. Mutations were made at the linkers for the purpose of disrupting the linker-linker interaction and, hence, synchronized linker movement. Five linker mutants were analyzed. Two of these contain 4-Ala insertions within the solvated region of the linker, and three have 3-residue deletions in this region. The efficiencies of the mutants for catalysis of the complete reaction as well as the E-His + ATP <--> E-His-PP.AMP partial reaction at the N-terminal domain and the E-His + PEP <--> E-His-P + pyruvate reaction at the C-terminal domain were measured to assess linker function. Three linker mutants are highly active catalysts at both active sites, and the fourth is highly active at one site but not the other. These results are interpreted as evidence against coordinated linker movement, and suggest instead that the linkers move independently as the central domain travels between active sites. It is hypothesized that while the linkers play a passive role in central domain-terminal domain docking, their structural design minimizes the conformational space searched in the diffusion process.

Effects of spectator ligands on the specific recognition of intrastrand platinum-DNA cross-links by high mobility group box and TATA-binding proteins

The results presented describe the effects of various spectator ligands, attached to a platinum 1,2-intrastand d(GpG) cross-link in duplex DNA, on the binding of high mobility group box (HMGB) domains and the TATA-binding protein (TBP). In addition to cisplatin-modified DNA, 15-base pair DNA probes modified by [Pt(1R,2R-diaminocyclohexane)](2+), cis-[Pt(NH(3))(cyclohexylamine)](2+), [Pt(ethylenediamine)](2+), cis-[Pt(NH(3))(cyclobutylamine)](2+), and cis-[Pt(NH(3))(2-picoline)](2+) were examined. Electrophoretic mobility shift assays show that both the A and B domains of HMGB1 as well as TBP discriminate between different platinum-DNA adducts. HMGB1 domain A is the most sensitive to the nature of the spectator ligands on platinum. The effect of the spectator ligands on protein binding also depends highly on the base pairs flanking the platinated d(GpG) site. Double-stranded oligonucleotides containing the AG*G*C sequence, where the asterisks denote the sites of platination, with different spectator ligands are only moderately discriminated by the HMGB proteins and TBP, but the recognition of dsTG*G*A is highly dependent on the ligands. The effects of HMGB1 overexpression in a BG-1 ovarian cancer cell line, induced by steroid hormones, on the sensitivity of cells treated with [Pt(1R,2R-diaminocyclohexane)Cl(2)] and cis-[Pt(NH(3))(cyclohexylamine)Cl(2)] were also examined. The results suggest that HMGB1 protein levels influence the cellular processing of cis-[Pt(NH(3))- (cyclohexylamine)](2+), but not [Pt((1R,2R)-diaminocyclohexane)](2+), DNA lesions. This result is consistent with the observed binding of HMGB1a to platinum-modified dsTG*G*A probes but not with the binding affinity of HMGB1a and HMGB1 to platinum-damaged dsAG*G*C oligonucleotides. These experiments reinforce the importance of sequence context in platinum-DNA lesion recognition by cellular proteins.

Investigation of the catalytic site within the ATP-grasp domain of Clostridium symbiosum pyruvate phosphate dikinase

Pyruvate phosphate dikinase (PPDK) catalyzes the interconversion of ATP, P(i), and pyruvate with AMP, PP(i), and phosphoenolpyruvate (PEP) in three partial reactions as follows: 1) E-His + ATP --> E-His-PP.AMP; 2) E-His-PP.AMP + P(i) --> E-His-P.AMP.PP(i); and 3) E-His-P + pyruvate --> E.PEP using His-455 as the carrier of the transferred phosphoryl groups. The crystal structure of the Clostridium symbiosum PPDK (in the unbound state) reveals a three-domain structure consisting of consecutive N-terminal, central His-455, and C-terminal domains. The N-terminal and central His-455 domains catalyze partial reactions 1 and 2, whereas the C-terminal and central His-455 domains catalyze partial reaction 3. Attempts to obtain a crystal structure of the enzyme with substrate ligands bound at the nucleotide binding domain have been unsuccessful. The object of the present study is to demonstrate Mg(II) activation of catalysis at the ATP/P(i) active site, to identify the residues at the ATP/P(i) active site that contribute to catalysis, and to identify roles for these residues based on their positions within the active site scaffold. First, Mg(II) activation studies of catalysis of E + ATP + P(i) --> E-P + AMP + PP(i) partial reaction were carried out using a truncation mutant (Tem533) in which the C-terminal domain is absent. The kinetics show that a minimum of 2 Mg(II) per active site is required for the reaction. The active site residues used for substrate/cofactor binding/activation were identified by site-directed mutagenesis. Lys-22, Arg-92, Asp-321, Glu-323, and Gln-335 mutants were found to be inactive; Arg-337, Glu-279, Asp-280, and Arg-135 mutants were partially active; and Thr-253 and Gln-240 mutants were almost fully active. The participation of the nucleotide ribose 2'-OH and alpha-P in enzyme binding is indicated by the loss of productive binding seen with substrate analogs modified at these positions. The ATP, P(i), and Mg(II) ions were docked into the PPDK N-terminal domain crevice, in an orientation consistent with substrate/cofactor binding modes observed for other members of the ATP-Grasp fold enzyme superfamily and consistent with the structure-function data. On the basis of this docking model, the ATP polyphosphate moiety is oriented/activated for pyrophosphoryl transfer through interaction with Lys-22 (gamma-P), Arg-92 (alpha-P), and the Gly-101 to Met-103 loop (gamma-P) as well as with the Mg(II) cofactors. The P(i) is oriented/activated for partial reaction 2 through interaction with Arg-337 and a Mg(II) cofactor. The Mg(II) ions are bound through interaction with Asp-321, Glu-323, and Gln-335 and substrate. Residues Glu-279, Asp-280, and Arg-135 are suggested to function in the closure of an active site loop, over the nucleotide ribose-binding site.

Vestibular discrimination of gravity and translational acceleration

According to Einstein's equivalence principle, linear accelerations experienced during translational motion are physically indistinguishable from changes in orientation relative to gravity experienced during tilting movements. Nevertheless, despite these ambiguous sensory cues provided by the primary otolith afferents, perceptual and motor responses discriminate between gravity and translational acceleration. There is growing evidence to suggest that the brain resolves this ambiguity primarily by combining signals from multiple sensors, the semicircular canals being a main extra otolith contributor. Here, we summarize the experimental evidence in support of the canal influences on the neural processing of otolith cues, provide specific experimental results in rhesus monkeys, and discuss and compare previously proposed models that combine otolith and semicircular-canal signals in order to provide neural estimates of gravity and linear acceleration.

LF15-0195 prevents the induction and inhibits the progression of rat anti-GBM disease

BACKGROUND

LF15-0195 is a novel immunosuppressant that is currently in phase II clinical trials for the treatment of vasculitis. This study examined whether LF15-0195 could suppress the induction and progression of rat anti-glomerular basement membrane (anti-GBM) glomerulonephritis.

METHODS

Rapidly progressive glomerulonephritis was induced in primed rats by the administration of anti-GBM serum. In the first experiment, LF15-0195 was given daily by subcutaneous injection (days 0 to 14) to treat the induction of anti-GBM disease analyzed at day 14. In a second experiment, rats received LF15-0195 as an intervention treatment from days 7 to 28 (continuous therapy) or days 7 to 12 (pulse therapy) to treat the progression of disease assessed at day 28.

RESULTS

Continuous LF15-0195 treatment during the induction of anti-GBM disease (experiment 1) prevented proteinuria and loss of renal function, and markedly reduced histological kidney lesions and renal fibrosis. LF15-0195 also reduced kidney leukocyte infiltrate, urine excretion of interleukin-1beta (IL-1beta) and transforming growth factor-beta (TGF-beta), and the serum antibody response, but not kidney deposition of Ig and C3. When LF15-0195 treatment was initiated at day 7, both continuous and pulse therapy partially inhibited disease progression by suppressing the loss of renal function, interstitial macrophage and T-cell accumulation, tubular cell proliferation, and renal fibrosis.

CONCLUSION

LF15-0195 prevents the induction and suppresses the progression of rat anti-GBM disease through multiple mechanisms of action, suggesting that this drug may have significant therapeutic potential in human glomerulonephritis. The similar efficacy of continuous and pulse intervention treatment in this model indicates that short-term LF15-0195 treatment may achieve optimal benefit without prolonged bone marrow suppression.

Cytokine responses and myocardial injury in coronary artery bypass grafting

OBJECTIVE

Cardiopulmonary bypass is acknowledged to be one of the major causes of a complex systemic inflammatory response after cardiac surgery, and it may contribute to postoperative complications and even multiple organ dysfunction. We here compared the cytokine responses and the degree of myocardial injury after coronary artery bypass grafting with or without cardiopulmonary bypass.

METHODS

Nine patients underwent off-pump revascularization and 13 with cardiopulmonary bypass. Plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, IL-8 and IL-10 were measured before anesthesia induction, and 5 min, 1, 4, and 20 h after reperfusion to the myocardium. Levels of the MB isoenzyme of creatine kinase (CK-MB) were also measured after the operation.

RESULTS

Levels of TNF-alpha were low in both groups. A delayed elevation of IL-6 was noted in the off-pump group. IL-8 and IL-10 levels were significantly higher in the CPB than in the off-pump patients after reperfusion (p=0.006 and 0.001 respectively). Postoperative CK-MB levels were significantly higher in the CPB than in the off-pump group (p=0.001). Cytokine levels correlated with CK-MB values.

CONCLUSION

The results indicated that off-pump revascularization was associated with reduced cytokine responses and less severe myocardial injury. The degree of myocardial injury, as defined by CK-MB release, correlated with cytokine release. Intervention designed to reduce cytokine responses in cardiac surgery may be advantageous for patients with severe comorbidity.

Cardioprotective effect of adenosine pretreatment in coronary artery bypass grafting

OBJECTIVE

There are several reports of the use of adenosine as a cardioprotective agent during cardiac surgery. Adenosine treatment might affect neutrophils and inflammatory mediators. The present prospective randomized study was designed to investigate the effect of adenosine pretreatment on myocardial recovery and inflammatory response in patients undergoing elective coronary artery bypass surgery.

DESIGN

A prospective, randomized, controlled study.

SETTING

Operative unit and ICU in a university hospital in Finland.

PATIENTS

Thirty male patients undergoing primary, elective coronary revascularization.

INTERVENTIONS

Patients in the adenosine group received a 7-min infusion of adenosine (total, 650 microg/kg) before the initiation of cardiopulmonary bypass.

MEASUREMENTS

Postoperative creatine kinase (CK)-MB release and hemodynamics were recorded. Perioperative leukocyte and cytokine release were measured.

RESULTS

Adenosine pretreatment resulted in less CK-MB release and an improved postbypass cardiac index. Similar leukocyte counts and cytokine responses were seen in both groups perioperatively. Neutrophil counts were similar between the groups before and after myocardial ischemia when measured simultaneously in arterial and coronary sinus blood.

CONCLUSIONS

The present results support the hypothesis that adenosine pretreatment is cardioprotective in humans, but the present dose failed to regulate the inflammatory responses after coronary artery bypass grafting.

[Experimental study on effect of bushen huoxue xiezhuo decoction in treating minimal change nephropathy]

OBJECTIVE

To explore the therapeutic effect and mechanism of Bushen Huoxue Xiezhuo Decoction (BHXD) in treating minimal change nephropathy (MCN) in rats.

METHODS

The MCN model rats established by a single intravenous injection of Adriamycin were divided into the model, BHXD group, and a normal group was set up for control. The effect of treatment on renal function, hemorrheologic parameters, renal tissue TGF-beta 1 expression and polyanion sites on glomerular basement membrane were observed dynamically.

RESULTS

After treatment, all the parameters between the BHXD group and the model group were significantly different respectively, morphological observation also showed the pathological changes in the BHXD group were milder than those in the model group.

CONCLUSION

BHXD treatment could markedly improve the renal function, alleviate blood hypercoagulability and hyperviscosity, protect the anion barrier and delay the progression of glomerular fibrosis and sclerosis.

Inflammatory cytokines and soluble receptors after coronary artery bypass grafting

Much interest has been focused on the overexpression of proinflammatory cytokines, but studies on their soluble receptors are rare. For a comprehensive picture of cytokine activation in cardiac surgery, a combination of cytokines and the corresponding soluble receptor concentration should be determined. Blood samples were collected from the radial artery and coronary sinus perioperatively in ten patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. TNF-alpha, IL-6, sTNFRI, sTNFRII, and sIL-6R levels in the plasma were determined. Systemic TNFRI, TNFRII and IL-6 increased significantly after reperfusion to the myocardium, while perioperative systemic sIL-6r levels were similar. Arterial and sinus levels of TNFRI, TNFRII and sIL-6r were similar before cardiopulmonary bypass. Five minutes after reperfusion to the myocardium, higher sinus TNFRI and TNFRII and lower sinus sIL-6R levels were observed as compared to the arterial levels. The myocardium release of sTNFRI (r=0.57, P=0.089) and sTNFRII (r=0.64, P=0.047) positively correlated with the change of cardiac index after cardiopulmonary bypass. Myocardium releases sTNFRI and sTNFRII after ischaemic-reperfusion injury, and this may be of benefit to cardiac performance. sIL-6R is constantly being produced in areas other than the myocardium, while sIL-6R levels are reduced by consumption in the myocardium after ischaemic-reperfusion injury.

Anti-inflammatory effects of 17beta-estradiol pretreatment in men after coronary artery surgery

OBJECTIVE

To investigate the anti-inflammatory and hemodynamic effects of 17beta-estradiol in men undergoing elective coronary artery bypass graft surgery (CABG).

DESIGN

Prospective, randomized, controlled.

SETTING

Operating room and intensive care unit in a university hospital.

PARTICIPANTS

Twenty-one men undergoing primary, elective CABG surgery.

INTERVENTION

17beta-estradiol, 2mg, was given orally twice in 14 hours before the operation.

MEASUREMENTS AND MAIN RESULTS

Leukocyte counts, plasma myeloperoxidase, tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, and IL-10 were measured perioperatively. Leukocyte counts were lower in the 17beta-estradiol group than in controls at 6 hours (11.4 +/- 2.0 hours v 15.5 +/- 4.7 hours x 10(9)/L) and 20 hours (11.6 +/- 1.9 hours v 13.6 +/- 2.5 hours x 10(9)/L) after reperfusion (p = 0.03). The release of myeloperoxidase was lower in the 17beta-estradiol group than in controls (5 minutes; 634.4 +/- 213.1 microg/mL v 773.1 +/- 209.3 microg/mL; 4 hours, 305.0 +/- 108.0 microg/mL v 441.3 +/- 191.6 microg/mL; p = 0.02). Systemic vascular resistance index was lower just after cardiopulmonary bypass, and cardiac index was higher postoperatively in the 17beta-estradiol group as compared with controls.

CONCLUSION

Pretreatment with 17beta-estradiol can limit leukocyte activation in men after CABG surgery.

Possible prevention by abieslactone of development of diethylnitrosamine-initiated GST-P positive foci in the rat liver

Triterpenoid compounds, isolated from plants of Abies genus (Pinceae), are known to exert anti-tumor promotion activities in mouse skin carcinogenesis. In the present study, we investigated whether AVB-1 and acid and acid methyl ester derivatives have inhibitory effects on rat hepatocarcinogenesis by using a liver medium-term bioassay for carcinogens (Ito's test), immunohistochemically assessing the numbers and areas per cm(2) of preneoplastic lesions, glutathione S-transferase placental form (GST-P)-positive foci. In experiment 1, 6-week-old male Fisher 344 rats were given a single intraperitoneal injection of diethylnitrosamine (200 mg/kg b.w.) and subjected to two-thirds partial hepatectomy at week 3. From weeks 2 to 8, the compounds were given three times a week at a dose of 1 mg/kg b.w. by i.g. gavage and found to significantly decrease the number of GST-P-positive foci in the liver. In experiment 2, AVB-1 was given three times a week at doses of 3, 1, or 0.3 mg/kg b.w. by i.g. gavage from weeks 2 to 8. All doses of AVB-1 significantly decreased the numbers of GST-P-positive foci. Thus, our results suggest that AVB-1 is a chemopreventive agent for rat hepatocarcinogenesis.

Autoxidation of substituted phenols catalyzed by cobalt Schiff base complexes in supercritical carbon dioxide

This first study of O(2) oxidation (autoxidation) of substituted phenols catalyzed by a dioxygen carrier in supercritical carbon dioxide (scCO(2)) provides additional insights into the established mechanism of reactions that have been much studied in conventional solvents. As has been long believed, the cobalt(II) dioxygen carriers of the class represented by [[N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminato(2-)]cobalt(II)], Co(salen), show both oxidase and oxygenase activities during oxygenation of substituted phenols in scCO(2). The catalytic autoxidation of 2,6-di-tert-butylphenol (DTBP) and 3,5-di-tert-butylphenol (35-DTBP) in scCO(2) was studied by analysis of products in batch reactions with carefully controlled variables, in the presence of a large excess of O(2), at 207 bar of total pressure and a reaction temperature of 70 degrees C. The oxidation of 35-DTBP yielded only traces of products under the same experimental conditions that converted DTBP totally to a mixture of the oxygenation product 2,6-di-tert-butyl-1,4-benzoquinone (DTBQ) and the related product of radical coupling 3,5,3',5'-tetra-tert-butyl-4,4'-diphenoquinone (TTDBQ). The effects on conversion of DTBP to products and on selectivity between the two products were studied for variations in temperature and the concentrations of catalyst, oxygen, and methylimidazole. Selectivity in favor of the O-transfer product DTBQ over the self-coupling of the phenoxy radical was observed upon changing the oxygen concentration. In contrast, selectivity remained unaffected over a wide range of temperatures and catalyst concentrations. The oxygen dependence of both the conversion and selectivity showed saturation effects identifying the dioxygen complex as the effective oxidant in both the initial radical formation step and the oxygenation of that radical. No direct reaction is observed between the electrophilic phenoxy radical and O(2).

Epigenetic heterogeneity at imprinted loci in normal populations

Genomic imprinting is the phenomenon by which the two alleles of certain genes are differentially expressed according to their parental origin. Extensive analysis of allelic expression at multiple imprinted loci in a normal population has not performed so far. In the present study, we examined the allelic expression pattern of three imprinted genes in a panel of 262 Japanese normal individuals. We observed differences in the extent of maintenance of allele-specific expression of the three genes. The allelic expression of small nuclear ribonucleoprotein N (SNRPN) was stringently regulated while that of multimembrane-spanning polyspecific transporter-like gene 1 (IMPT1) showed a large degree of variation. Significant biallelic expression of insulin-like growth factor II (IGF2) was observed in about 10% of normal individuals. Our findings add to the accumulating evidence for variable allelic expression at multiple loci in a normal human population. This epigenetic heterogeneity can be a stable trait and potentially influence individual phenotypes.

[Subtotal laryngectomy reconstructed by platysma myocutaneous flaps]

OBJECTIVE

To study the feasibility, surgical techniques and the results of laryngeal function preservation during subtotal laryngectomy in laryngeal carcinoma.

METHODS

A retrospective review was made of 13 patients treated by subtotal laryngectomy and laryngeal reconstruction from 1991 to 1996. Eleven patients were male and 2 were female. The age ranged from 46 to 72 years, with a mean of 53.25. All cases were of stage IV. The essence of this operation is to reconstruct the new larynx with two platysma myocutaneous flaps following subtotal laryngectomy.

RESULTS

The success rate of voice rehabilitation was 100%. Among them, the acceptability rating scores in 11 cases were 7 and the intelligibility scores ranged from 95% to 98%. The other two cases had acceptability 5 and intelligibility form 90% to 94%. The three-year survival rate was 84.6% (11/13), 5-year survival rate was 76.9% (10/13).

CONCLUSION

This form of laryngeal reconstruction in subtotal laryngectomy is helpful to restore laryngeal function and decrease the rate of total laryngectomy. The procedure is easy, safe and applicable to patients treated by subtotal laryngectomy.

Cross-axis adaptation of the translational vestibulo-ocular reflex

The adaptive plasticity of the translational vestibulo-ocular reflex (VOR) was investigated in rhesus monkeys after 2-h exposure to either vertical or torsional optic flow stimulation accompanied by lateral translation stimuli (0.5 Hz). Because of the inherent ambiguity in the otolith system for the detection of gravitoinertial accelerations, we hypothesized that cross-axis adaptation of the translational VOR during lateral motion would be preferentially selective for a torsional optic flow stimulus that would mimic a roll tilt movement. However, we found that both vertical and torsional adaptation was possible. Furthermore, there was no significant preference for whether the torsional adaptation was in phase or out of phase with the apparent tilt induced by the motion stimulus. These results suggest that, at least at 0.5 Hz, there seems to be no preferential, visually induced adaptive capacity of the otolith system for tilt/translation reinterpretation during motion. Like the rotational VOR, translational VOR appears to exhibit a general form of cross-axis adaptation that operates for different directions of optic flow stimulation.

Cephalometric image analysis and measurement for orthognathic surgery

Automatic identification of landmarks in cephalometry is very important and useful for orthognathic surgery. A computerised automatic cephalometric analysis system (CACAS), based on image processing, is presented. For an original X-ray image, median filtering and histogram equalisation are used to improve image quality. The edge of an X-ray image is detected by a wavelet transform and Canny filter. Seventeen landmarks in cephalometry are successfully identified by knowledge-based edge tracing and changeable templates. Seventy-three measurements based on distances, angles and ratios between landmarks are computed automatically. The reliability of the landmarks and the validity of the measurements are compared for automatic and manual operation. The values of measurements obtained by CACAS are more precise and reliable: the mean error for linear measurements is less than 0.9mm; the mean error for angular measurements is less than 1.2 degrees. The rate of validity is over 80%, even if the image quality is poor. For an image with a high signal-to-noise ratio, the rate of validity of landmarking and measurements using the CACAS system is over 90%.

Cytokine responses in patients undergoing coronary artery bypass surgery after ischemic preconditioning

OBJECTIVE

The release of proinflammatory cytokines has been shown to be associated with the development of complications after coronary artery bypass grafting with cardiopulmonary bypass. The purpose of the present study was to establish whether ischemic preconditioning (IP) could limit inflammatory cytokines release in patients undergoing elective coronary artery bypass surgery.

METHODS

Twenty-two patients with multiple-vessel coronary artery disease and stable angina admitted for first-time elective coronary artery bypass surgery were randomized into control or ischemic preconditioning groups. Patients in the IP group were exposed to two cycles of two-minute myocardial ischemia, followed by three minutes of reperfusion, at the beginning of the revascularization operation, before the cross-clamping and ischemic period used for coronary artery bypass graft anastomosis. Peripheral plasma levels of TNF-alpha, IL-6, IL-8 and IL-10 were measured perioperatively.

RESULTS

Significant elevation of IL-6, IL-8 and IL-10 were observed in both groups after reperfusion. Ischemic preconditioning has no effect on cytokine release in the early stage after reperfusion. Arterial blood IL-6 levels in the preconditioning group were significantly lower than in controls at 20 h after declamping (52.93 +/- 9.79 vs 96.04 +/- 17.56 pg/ml, p < 0.05).

CONCLUSIONS

The results indicate that ischemic preconditioning results in no effect on systemic inflammatory cytokine release in the early stage but a delayed reduction in IL-6 levels at 20 h after reperfusion.

The association between physical activity, physical fitness, and type 2 diabetes mellitus

Recent studies have shown that cardiorespiratory fitness--an objective measurement of physical activity--is a strong predictor of type 2 diabetes. Self-reported physical activity is also associated with decreased risk of developing diabetes.

Presence of a no-observed effect level for enhancing effects of development of the alpha-isomer of benzene hexachloride (alpha-BHC) on diethylnitrosamine-initiated hepatic foci in rats

The dose dependence of the promoting effects of the alpha-isomer of benzene hexachloride (alpha-BHC) on hepatocarcinogenesis was investigated in a medium-term rat liver bioassay (Ito test). A total of 195 F344 male rats, 6 weeks old, were given a single intraperitoneal injection of diethylnitrosamine (DEN) at the start of the experiment and subjected to two-thirds partial hepatectomy at week 3. Two weeks after the administration of DEN, alpha-BHC were fed to rats at doses of 0, 0.01, 0.1, 0.5, 1, 2, 4, 7.5, 15, 30, 60, 125 and 500 ppm in diet for 6 weeks. All surviving animals were killed at week 8, and their livers were examined immunohistochemically for detection of glutathione S-transferase placental form (GST-P)-positive foci, surrogate preneoplastic lesions. Quantitative values for numbers and areas were dose-dependently increased in rats given alpha-BHC at 0.5-500 ppm. However, those for groups treated with 0.01 and 0.1 ppm were decreased, albeit not significantly in comparison to the controls. Cytochrome P450 3A2 (CYP3A2) protein levels and activities showed a good correlation to the number and area of GST-P-positive foci. These results support evidence of hormesis and indicate a no-observed effect level for alpha-BHC promoting potentials may exist regarding rat liver carcinogenesis, which correlates with expression of CYP3A2 in the liver.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Identification of domain-domain docking sites within Clostridium symbiosum pyruvate phosphate dikinase by amino acid replacement

Potential domain-domain docking residues, identified from the x-ray structure of the Clostridium symbiosum apoPPDK, were replaced by site-directed mutagenesis. The steady-state and transient kinetic properties of the mutant enzymes were determined as a way of evaluating docking efficiency. PPDK mutants, in which one of two stringently conserved docking residues located on the N-terminal domain (Arg(219) and Glu(271)) was substituted, displayed largely unimpeded catalysis of the phosphoenolpyruvate partial reaction at the C-terminal domain, but significantly impaired catalysis (>10(4)) of the ATP pyrophosphorylation of His(455) at the N-terminal domain. In contrast, alanine mutants of two potential docking residues located on the N-terminal domain (Ser(262) and Lys(149)), which are not conserved among the PPDKs, exhibited essentially normal catalytic turnover. Arg(219) and Glu(271) were thus proposed to play an important role in guiding the central domain and, hence, the catalytic His(455) into position for catalysis. Substitution of central domain residues Glu(434)/Glu(437) and Thr(453), the respective docking partners of Arg(219) and Glu(271), resulted in mutants impaired in catalysis at the ATP active site. The x-ray crystal structure of the apo-T453A PPDK mutant was determined to test for possible misalignment of residues at the N-terminal domain-central domain interface that might result from loss of the Thr(453)-Glu(271) binding interaction. With the exception of the mutation site, the structure of T453A PPDK was found to be identical to that of the wild-type enzyme. It is hypothesized that the two Glu(271) interfacial binding sites that remain in the T453A PPDK mutant, Thr(453) backbone NH and Met(452) backbone NH, are sufficient to stabilize the native conformation as observed in the crystalline state but may be less effective in populating the reactive conformation in solution.

Chemopreventive effects of S-methylcysteine on rat hepatocarcinogenesis induced by concurrent administration of sodium nitrite and morpholine

The aim of the present study was to examine the chemopreventive efficacy of S-methylcysteine (SMC) on rat hepatocarcinogenesis induced by concurrent administration of sodium nitrite (NaNO(2)) and morpholine (Mor) using a medium-term rat liver carcinogenesis bioassay (Ito test). Administration of SMC caused significant reduction in the areas of glutathione S-transferase placental form positive foci along with a significant decrease of hepatocyte 5-bromo-2'-deoxyuridine (BrdU) labeling indices. These results demonstrated potent chemopreventive effects of SMC against hepatocarcinogenesis due to concurrent administration of Mor and NaNO(2). SMC could thus be an effective chemopreventive agent for decreasing the risk of carcinogenicity from environmental precursors of N-nitroso compounds.

Glomerulosclerosis in adriamycin-induced nephrosis is accelerated by a lipid-rich diet

The present study was performed to determine quantitatively the effect of hypercholesterolemia induced by a lipid-rich diet on glomerulosclerosis in an animal model of nephrotic syndrome (NS) induced by Adriamycin (ADR). Twenty NS Wistar rats administered ADR with a single intravenous dose of 5 mg/kg body weight were divided into standard and lipid-rich chow groups. Another 20 weight-matched non-NS rats that received a vehicle alone were grouped as controls. Quantitative analyses of renal histological changes were performed with determination of blood and urine biochemical parameters. It was found that serum cholesterol was markedly higher in rats with lipid-rich chow in both NS and non-NS rats. Urinary protein was significantly higher in rats on the lipid-rich diet in the NS group. The mesangial matrix and cell indices were significantly increased in rats with the lipid-rich diet and the most obvious changes were found in the NS group. Lipid deposits and foam cells were observed in mesangial areas, and some glomeruli had progressed to form focal and segmental glomerulosclerosis in the NS group. Findings indicated that diet-induced hyperlipidemia can lead to proliferation of mesangial cells and accumulation of mesangial matrices, and further aggravate glomerulosclerosis in Adriamycin-induced nephrosis.

[Wind-damage effects on quality of heartwood of Lignum Santali Albi]

OBJECTIVE

To evaluate the wind-damage effects on quality of heartwood of Lignum Santali Albi.

METHOD

GC-MS, TLC and pharmacodynamic test.

RESULTS

The content of volatile oil from heartwood of Wind-damaged Lignum Santali Albi is 1.42%; the content of various components in the oil and the chromatography of different extracts are similar to those of reference drug and 25 years old trees.

CONCLUSION

Wind-damage should accelerate the formation of heartwood of Lignum Santali Albi without influence on its quality.

Open-loop and closed-loop optokinetic nystagmus (OKN) in myasthenia gravis and nonmyasthenic subjects

Optokinetic nystagmus (OKN) eye movements of myasthenia gravis (MG) and nonmyasthenic ocular palsies, and normal subjects were examined under closed-loop and open-loop conditions. The open-loop OKN condition was achieved by adding the signal of eye-movement velocity of OKN to the computer-generated signal controlling the stimulus grating moving. The OKN was recorded by means of electromagnetic search scleral coil technique. In MG patients, the open-loop gains of OKN increased significantly after the intramuscular injection of an acetylcholinesterase inhibitor, neostigmine, while the closed-loop OKN gains were not significantly changed. Both the closed-loop and open-loop OKN gains of normal subjects and nonmyasthenic patients were not increased for the administration of neostigmine. The experimental results indicated that the open-loop OKN gain could be sensitive to reflect the changes of the function of neuromuscular junction in MG patients.

[Effect of high-lipid diet on glomerular mesangial matrix in adriamycin-induced nephrotic rats]

OBJECTIVE

To determined the effect of hypercholesterolemia induced by high-lipid diet on glomerulosclerosis.

METHODS

Urinary protein excretion and serum cholesterol were assayed, Image analysis and techniques of pathology, immunohistochemistry, molecular biology were used to determine morphological changes in glomeruli and the production of glomerular mesangial matrixes in adriamycin-induced nephrotic syndrome (NS) and non-NS rats fed with standard chow and high-lipid chow.

RESULTS

The serum total cholesterol level was significantly higher in rats with high-lipid chow in both non-NS[(2.2 +/- 0.3) g/L vs (0.9 +/- 0.1) g/L, P < 0.01] and NS[(9.5 +/- 0.2) g/L vs (2.3 +/- 0.3) g/L, P < 0.01]. The urinary protein excretion was significantly higher in the high-lipid diet rats than that in standard chow rats [(76.2 +/- 24.2) mg/24 h vs (44.8 +/- 13.6) mg/24 h, P < 0.05] in NS rats. Significant increases in the mesangial matrix and mesangial cells were observed in rats with high-lipid diet in both NS and non-NS group. Especially, more obvious pathological changes were found in NS group, such as lipid deposits and foam cell formation in mesangial areas, and progressing to focal and segmental glomerulosclerosis in some glomeruli. The immunohistochemical assay showed that the production of fibronectin was increased in the rats with high-lipid diet in non-NS group, whereas, the production of three major components (collagen IV, fibronectin, and laminin) was increased in NS group, especially in the rats with high-lipid chow. The increased expression of laminin mRNA was also detected with slot blotting in both NS and non-NS rats with high-lipid chow, and it was more obvious in the rats with NS.

CONCLUSION

Our findings indicated that diet-induced hyperlipidemia can lead to over-production of mesangial matrix components, and further aggravate glomerulosclerosis in adriamycin-induced nephrosis.

Sedentary habits, health, and function in older women and men

PURPOSE

To evaluate the relation of physical activity and cardiorespiratory fitness to morbidity, mortality, and functional limitations in older persons.

DATA SOURCES

We reviewed published reports related to the review's purpose. Sources were identified from recent major reports and position statements from scientific and public health organizations, our files, and reference lists of published papers.

STUDY INCLUSION AND EXCLUSION CRITERIA

We included prospective epidemiological studies and clinical trials published in the peer-reviewed literature that included data from age groups of people 60 years and older. We evaluated study methods and included studies that used valid measures of exposures, clearly specified outcomes, and controlled for confounders.

DATA EXTRACTION METHODS

We extracted by detailed review data on sample characteristics, outcomes, and rates and relative risks.

DATA SYNTHESIS

Extracted data were included in tables, figures, or the text and were synthesized by nonquantitative methods.

MAJOR CONCLUSIONS

Active and fit individuals were at much lower risk for morbidity, mortality, and loss of function when compared with sedentary and unfit persons. Data from the studies generally conformed to a steep inverse dose-response gradient across activity or fitness categories. Results were consistent, temporally appropriate, strong, and graded, and therefore support a causal hypothesis that a fit and active way of life improves health and function in older individuals.

[Study on treatment of hyperandrogenism and hyperinsulinism in polycystic ovary syndrome with Chinese herbal formula "tiangui fang"]

OBJECTIVE

To observe the efficacy of Chinese herbal formula "Tiangui Fang" (TGF) in hyperandrogenism and hyperinsulinism patients of polycystic ovarian syndrome (PCOS), and compare with western medicine metformin.

METHODS

Twenty-two anti-clomiphen citrite patients were divided into two treatment groups: "Tiangui Fang" (n = 10) and metformin (n = 12) for three months. Insulin response during oral glucose tolerance test and serum level of LH, FSH, testosterone (T), estradiol (E2) and waist to hip ratio (WHR), body mass index (BMI) were measured before and after treatment.

RESULTS

After treatment for three months with metformin or TGF, fasting and the integrated insulin response to the glucose load decreased. Treated by metformin 4 out of 8 patients had restoration of menstrual cyclicity and 2 of them had double phase bases body temperature (BBT). This was accompanied by lowering in serum logT/E2 but had no significant difference, the BMI, WHR and serum E2, LH:FSH ratio were not changed. Treated by TGF for three months, 6 out of 8 patients had restoration of menstrual cyclicity and double phase BBT. This was accompanied by significant lowering in serum T, logT/E2 and BMI (P < 0.05), serum LH:FSH ratio were not changed.

CONCLUSION

Both metformin and TGF can reduce the high concentration of insulin in PCOS patients and induce ovulation, the herbal formula has a better efficacy.

Inhibition by ginseng of 1,2-dimethylhydrazine induction of aberrant crypt foci in the rat colon

The modifying effects of dietary administration of ginseng on the induction and development of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) were investigated in Fischer 344 (F-344) rats. In Experiment 1, starting at six weeks of age, 65 rats were injected with DMH or saline alone once a week for four weeks. Rats in Groups 1 and 2 were fed diets containing 1% ginseng for five weeks, starting one week before the first dose of DMH. Animals in Groups 3 and 4 received ginseng for eight weeks after DMH treatment; Group 5 served as a carcinogen control group. In Experiment 2, 60 rats were injected with DMH or saline alone four times at one-week intervals. They were also fed diets containing 1% ginseng or the control diet throughout the 30 days of the experiment. In Experiment 1, numbers of foci with at least four crypts were significantly reduced in Group 2 treated with red ginseng during the initiation phase (p < 0.005). In Experiment 2, treatment with red ginseng also resulted in a decrease in the total number of DMH-induced ACF accompanied by a reduction in 5-bromo-2'-deoxyuridine labeling indexes in colonic crypts comprising ACF (p < 0.005 and p < 0.05, respectively). These findings suggest that dietary administration of red ginseng in combination with DMH suppresses colon carcinogenesis of rats, and the inhibition may be associated, in part, with suppression of cell proliferation in the colonic mucosa.

Maximal exercise test as a predictor of risk for mortality from coronary heart disease in asymptomatic men

Exercise testing in asymptomatic persons has been criticized for failing to accurately predict those at risk for coronary heart disease (CHD). Previous studies on asymptomatic subjects, however, may not have been large enough or long enough to provide reliable outcome measures. This study examines the ability of a maximal exercise test to predict death from CHD and death from any cause in a population of asymptomatic men. This is a prospective longitudinal study performed between 1970 and 1989, with an average follow-up of 8.4 years. The subjects are 25,927 healthy men, 20 to 82 years of age at baseline (mean 42.9 years) who were free of cardiovascular disease and who were evaluated in a preventive medicine clinic. The main outcome measures are CHD mortality and all-cause mortality. During follow-up there were 612 deaths from all causes and 158 deaths from CHD. The sensitivity of an abnormal exercise test to predict coronary death was 61%. The age-adjusted relative risk of an abnormal exercise test for CHD death was 21 (6.9 to 63.3) in those with no risk factors, 27 (10.7 to 68.8) in those with 1 risk factor, 54 (21.5 to 133.7) in those with 2 risk factors, and 80 (30.0 to 212. 5) in those with >/=3 factors. A maximal exercise test performed in asymptomatic men free of cardiovascular disease does appear to be a worthwhile tool in predicting future risk of CHD death. An abnormal exercise test is a more powerful predictor of risk in those with than without conventional risk factors.

Low fasting plasma glucose level as a predictor of cardiovascular disease and all-cause mortality

BACKGROUND

Although medical textbooks usually classify fasting plasma glucose <70 or 80 mg/dL (<3.89 or 4.44 mmol/L) as abnormal, the prognosis for patients with low fasting plasma glucose is unclear.

METHODS AND RESULTS

We conducted prospective cohort studies among 40 069 men and women to investigate the association between fasting plasma glucose levels and cardiovascular disease and all-cause mortality. We documented a U-shaped relation between fasting plasma glucose and mortality. In addition to diabetes and impaired fasting glucose levels, low fasting plasma glucose levels were also associated with high mortality. After multivariate adjustment for age, sex, study population, ethnicity, current smoking status, high blood pressure, total cholesterol, body mass index, triglycerides, history of cardiovascular disease and cancer, and a family history of cardiovascular disease, patients with fasting plasma glucose <70 mg/dL (<3.89 mmol/L) had a 3.3-fold increased risk of cardiovascular disease mortality, and patients with fasting plasma glucose 70 to 79 mg/dL (3.89 to 4.43 mmol/L) had a 2.4-fold increased risk compared with the risk in patients with fasting plasma glucose 80 to 109 mg/dL (4.44 to 6.05 mmol/L) (tests for trend P<0.0001). Participants with low fasting plasma glucose levels also had increased risk of all-cause mortality (test for trend P<0.0001).

CONCLUSIONS

Participants with low fasting plasma glucose levels had a high risk of cardiovascular disease and all-cause mortality.

Low cardiorespiratory fitness and physical inactivity as predictors of mortality in men with type 2 diabetes

BACKGROUND

Although physical activity is recommended as a basic treatment for patients with diabetes, its long-term association with mortality in these patients is unknown.

OBJECTIVE

To evaluate the association of low cardiorespiratory fitness and physical inactivity with mortality in men with type 2 diabetes.

DESIGN

Prospective cohort study.

SETTING

Preventive medicine clinic.

PATIENTS

1263 men (50+/-10 years of age) with type 2 diabetes who received a thorough medical examination between 1970 and 1993 and were followed for mortality up to 31 December 1994.

MEASUREMENTS

Cardiorespiratory fitness measured by a maximal exercise test, self-reported physical inactivity at baseline, and subsequent death determined by using the National Death Index.

RESULTS

During an average follow-up of 12 years, 180 patients died. After adjustment for age, baseline cardiovascular disease, fasting plasma glucose level, high cholesterol level, overweight, current smoking, high blood pressure, and parental history of cardiovascular disease, men in the low-fitness group had an adjusted risk for all-cause mortality of 2.1 (95% CI, 1.5 to 2.9) compared with fit men. Men who reported being physically inactive had an adjusted risk for mortality that was 1.7-fold (CI, 1.2-fold to 2.3-fold) higher than that in men who reported being physically active.

CONCLUSIONS

Low cardiorespiratory fitness and physical inactivity are independent predictors of all-cause mortality in men with type 2 diabetes. Physicians should encourage patients with type 2 diabetes to participate in regular physical activity and improve cardiorespiratory fitness.

[The influence of external stimulation on content and quality of volatile oil in Lignun Santali albi]

The authors analyzed the quality of Ligmum Santali Albi formed by the external stimulation of hormone and windburn by GC-MS-DS. The results showed that the content of volatile oil is 2.34% in the heart wood formed in 10 years tree age of Santalum album (SA) after 2 years stimulation continuously with a definite concentration of hormone, which is near to the 25 years tree age of SA in the same place. The GC-MS analysis showed that the content of santalol and other chemical components in volatile oil are similar to the 25 years tree age of SA. It is indicated that a definite concentration of hormone stimulated the SA may shorten the formation of the heart wood. The heart wood can be also formed by the broken branches after 2 years windburn, but its content of volatile oil is only 1/2 of the heart wood formed by hormone stimulation.

[Effect of inflammatory factor and yishen huoxue xiezhuo decoction on growth of glomerular mesangial cells in rats]

OBJECTIVE

To explore the part of inflammatory factors (cytokines) and Yishen Huoxue Xiezhuo (YSHXXZ) Decoction on the proliferation of extracorporeal cultured mesangial cells (MCs) in rats.

METHODS

The effects of lipopolysaccharide (LPS) and interleukin-6 (IL-6) as stimulating factors, its action on the proliferation of rat MCs were investigated by using the technique of 3H-TdR incorporation. Meanwhile, adopting serum pharmacology assay, the medicated serum of rat, containing YSHXXZ decoction was extracted and its effects on the growth of MCs were also studied.

RESULTS

LPS and IL-6, in a dose-dependent and time-dependent manner, could markedly stimulate the MCS proliferation, while this stimulatory effects could be strongly antagonized by the serum containing YSHXXZ decoction.

CONCLUSION

Mesangial cell is the main target cell of the action of YSHXXZ decoction, and the inhibition on MCs might be one of the mechanisms of the YSHXXZ decoction in preventing the progression of chronic glomerulonephritis.

Exposure to 60-Hz magnetic fields and proliferation of human astrocytoma cells in vitro

Epidemiological studies have suggested that exposure to electric and magnetic fields (EMF) may be associated with an increased incidence of brain tumors, most notably astrocytomas. However, potential cellular or molecular mechanisms involved in these effects of EMF are not known. In this study we investigated whether exposure to 60-Hz sinusoidal magnetic fields (0.3-1.2 G for 3-72 h) would cause proliferation of human astrocytoma cells. Sixty-Hertz magnetic fields (MF) caused a time- and dose-dependent increase in proliferation of astrocytoma cells, measured by (3)H-thymidine incorporation and by flow cytometry, and strongly potentiated the effect of two agonists (the muscarinic agonist carbachol and the phorbol ester PMA). However, MF had no effect on DNA synthesis of rat cortical astrocytes, i.e., of similar, nontransformed cells. To determine the amount of heating induced by MF, temperatures were also recorded in the medium. Both 1.2 G MF and a sham exposure caused a 0.7 degrees C temperature increase in the medium; however, (3)H-thymidine incorporation induced by sham exposure was significantly less than that caused by MF. GF 109203X, a rather specific protein kinase C (PKC) inhibitor, and down-regulation of PKC inhibited the effect of MF on basal and on agonist-stimulated (3)H-thymidine incorporation. These data indicate that MF can increase the proliferation of human astrocytoma cells and strongly potentiate the effects of two agonists. These findings may provide a biological basis for the observed epidemiological associations between MF exposure and brain tumors.

Alcohol intake and incidence of type 2 diabetes in men

OBJECTIVE

To evaluate the relation between alcohol intake and incidence of type 2 diabetes.

RESEARCH DESIGN AND METHODS

This prospective study included 8,663 men with fasting plasma glucose measurements from at least two medical examinations. Alcohol intake was classified into five groups: nondrinkers and four quartiles (Qs) of drinkers according to the amount of alcohol intake. Type 2 diabetes was diagnosed by 1997 American Diabetes Association criteria.

RESULTS

There were 149 incident cases of type 2 diabetes during 52,588 person-years of follow-up. There was a U-shaped association between alcohol intake and diabetes, with the lowest incidence of diabetes at Q2 (61.9-122.7 g/week). As compared with Q2, men in Q3 and Q4 had a 2.2- (95% CI 1.2-3.9, P = 0.01) and 2.4-fold (1.4-4.4, P<0.01) risk of developing diabetes, while nondrinkers and men in Q1 had 1.8- (1.0-3.3, P<0.05) and 1.4-fold (0.7-2.6, P = 0.34) higher risk of diabetes, respectively. These associations persisted after adjustment for age, fasting plasma glucose, smoking, BMI, blood pressure, serum triglyceride concentration, cardiorespiratory fitness, HDL cholesterol, waist circumference, and parental diabetes.

CONCLUSIONS

We observed an elevated risk of developing type 2 diabetes in nondrinkers and men with high alcohol intakes, when compared with men who reported moderate alcohol intake. Men with a high alcohol intake may be able to reduce their risk of developing type 2 diabetes if they drink less.

Do Mexican Americans really have low rates of cardiovascular disease?

In this article we challenge the conclusion made from vital statistics that Hispanic Americans have lower all-cause and cardiovascular disease (CVD) mortality than non-Hispanic whites. There is reason to believe that vital statistics underascertain minority, and in particular Hispanic, deaths. Cohort studies minimize many of these limitations. In the San Antonio Heart Study risk factor distributions predicted higher all-cause and CVD mortality among Mexican Americans than among non-Hispanic whites. Follow-up of the cohort confirmed a mortality ratio of 1.38 for all-cause and 1.30 for CVD mortality for Mexican Americans vs non-Hispanic whites. This excess risk was confined to U.S.-born Mexican Americans, since immigrants from Mexico had very low mortality despite low socioeconomic status. We attribute this latter finding to a "healthy migrant effect."

[Establishment of the animal models of mandibular distraction osteogenesis]

OBJECTIVE

To establish the animal models of mandibular distraction osteogenesis in rabbits and study its osteogenetic mechanism.

METHODS

The right mandibles just anterior to the first molars of 12 rabbits were performed osteotomies, and the mandibles were positioned with distractors. The left mandibles were control group without operation. After 1 week, the distractors were stretched 0.9 mm every day for 10 days progressively. One day, 2, 4, 8 weeks after distraction, the mandibles were studied with gross measurement, X-ray, and histological examination.

RESULTS

The right mandible were lengthened 8.3 mm on average without bone nonunion and deformity healing. It was observed that the gaps between the distracted bone edges were first occupied by fibrous tissue. Two weeks after distraction, it was found that the gaps were bridged by callus in X-ray, the new bone and the normal bone could not be differentiated clearly after 8 weeks. In histological sections, there were collagen bundles in early distraction, then those collagen bundles were calcificated and become trabeculaes. No Cartilage was found during distraction.

CONCLUSION

It suggests that the rabbit mandible can be lengthened by distraction osteogenesis, and the new bone is formed by intramembranous ossification.

Concentration dependent promoting effects of sodium L-ascorbate with the same total dose in a rat two-stage urinary bladder carcinogenesis

Sodium L-ascorbate (Na-AsA) has been demonstrated to be a strong promoter of rat urinary bladder tumor development initiated by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). In the present study, we investigated variation in its promoting activity when the same total dose was given with different concentrations and exposure times. After 4 weeks administration of 0.05% BBN, group 1 served as a control without any post-initiation treatment. The rats in groups 2-4 received 1.25% Na-AsA diet for 36 weeks, 2.5% Na-AsA for 18 weeks and 5% Na-AsA for 8 weeks, respectively. Tumor number (papillomas and carcinomas) was greatest in group 3, and area in group 4 (P < 0.05). However, no enhancement was noted in group 2, although preneoplastic lesions were significantly increased. These results suggest that with the same total administration dose, high concentration of Na-AsA has the strongest promoting effects on tumor development in urinary bladder carcinogenesis.

Relationship between low cardiorespiratory fitness and mortality in normal-weight, overweight, and obese men

CONTEXT

Recent guidelines for treatment of overweight and obesity include recommendations for risk stratification by disease conditions and cardiovascular disease (CVD) risk factors, but the role of physical inactivity is not prominent in these recommendations.

OBJECTIVE

To quantify the influence of low cardiorespiratory fitness, an objective marker of physical inactivity, on CVD and all-cause mortality in normal-weight, overweight, and obese men and compare low fitness with other mortality predictors.

DESIGN

Prospective observational data from the Aerobics Center Longitudinal Study.

SETTING

Preventive medicine clinic in Dallas, Tex.

PARTICIPANTS

A total of 25714 adult men (average age, 43.8 years [SD, 10.1 years]) who received a medical examination during 1970 to 1993, with mortality follow-up to December 31, 1994.

MAIN OUTCOME MEASURES

Cardiovascular disease and all-cause mortality based on mortality predictors (baseline CVD, type 2 diabetes mellitus, high serum cholesterol level, hypertension, current cigarette smoking, and low cardiorespiratory fitness) stratified by body mass index.

RESULTS

During the study period, there were 1025 deaths (439 due to CVD) during 258781 man-years of follow-up. Overweight and obese men with baseline CVD or CVD risk factors were at higher risk for all-cause and CVD mortality compared with normal-weight men without these predictors. Using normal-weight men without CVD as the referent, the strongest predictor of CVD death in obese men was baseline CVD (age- and examination year-adjusted relative risk [RR], 14.0; 95% confidence interval [CI], 9.4-20.8); RRs for obese men with diabetes mellitus, high cholesterol, hypertension, smoking, and low fitness were similar and ranged from 4.4 (95% CI, 2.7-7.1) for smoking to 5.0 (95% CI, 3.6-7.0) for low fitness. Relative risks for all-cause mortality in obese men ranged from 2.3 (95% CI, 1.7-2.9) for men with hypertension to 4.7 (95% CI, 3.6-6.1) for those with CVD at baseline. Relative risk for all-cause mortality in obese men with low fitness was 3.1 (95% CI, 2.5-3.8) and in obese men with diabetes mellitus 3.1 (95% CI, 2.3-4.2) and as slightly higher than the RRs for obese men who smoked or had high cholesterol levels. Low fitness was an independent predictor of mortality in all body mass index groups after adjustment for other mortality predictors. Approximately 50% (n = 1674) of obese men had low fitness, which led to a population-attributable risk of 39% for CVD mortality and 44% for all-cause mortality. Baseline CVD had population attributable risks of 51% and 27% for CVD and all-cause mortality, respectively.

CONCLUSIONS

In this analysis, low cardiorespiratory fitness was a strong and independent predictor of CVD and all-cause mortality and of comparable importance with that of diabetes mellitus and other CVD risk factors.

Variations of synaptotagmin I, synaptotagmin IV, and synaptophysin mRNA levels in rat hippocampus during the estrous cycle

Periodic changes in ovarian steroid levels during fertility cycles affect learning both in humans and in rats in parallel with electrophysiological and morphological fluctuations in selective neuronal populations. In particular, during the estrous cycle of the female rat, hippocampal CA1 region undergoes cyclic modifications in synaptic density. To investigate the molecular mechanisms involved in synaptic remodeling during the estrous cycle, we analyzed the expression of three presynaptic markers, synaptotagmin I, synaptotagmin IV, and synaptophysin, in the female adult rat brain by in situ hybridization. Relative abundance in mRNA for these three markers was quantified at four phases of the estrous cycle: diestrus, proestrus (AM and PM), and estrus. mRNA levels for syt1 exhibited cyclic variations in pyramidal neurons of the CA3 region of hippocampus during the estrous cycle, while mRNA levels for syt4 and SYN were relatively invariant in this or other regions of the hippocampus. Because CA3 pyramidal neurons make synaptic contacts in CA1, modulation of syt1 expression in CA3 may participate in the changes in synaptic density observed in CA1 during the estrous cycle. Furthermore, both syt1 and SYN mRNA varied cyclically in layer II, but not in layer III of entorhinal cortex, while syt4 remained unchanged throughout the cycle. These data suggest that regular variations in steroid hormone levels during fertility cycles may alter the properties of several networks involved in information processing and learning and memory through altered levels of presynaptic proteins.

Urinary bladder carcinogenicity of dimethylarsinic acid in male F344 rats

The present study was conducted to determine the carcinogenicity of dimethylarsinic acid (DMA) administered to male F344 rats in a 2 year bioassay. A total of 144 rats (10 weeks old at the start) were divided into four groups of 36 rats each. Groups 1-4 received DMA (purity 100%) at concentrations of 200, 50, 12.5 and 0 p.p.m. in the drinking water, respectively, for 104 weeks. From weeks 97 to 104, urinary bladder tumors were observed in 12 of 31, eight of 31 and none of 33 in groups 1-3, respectively. No bladder tumors were observed in group 4. The present study demonstrated that long-term p. o. administration of DMA induced urinary bladder carcinomas in male F344 rats. Therefore, the results indicate that DMA is carcinogenic for the rat urinary bladder, which may be related to the human carcinogenicity of arsenicals.

[Design of CXLY-II low frequency magnetic fields pulse generator]

An experimental device, low frequency magnetic fields pulse generator, has been designed and accomplished in our department. It can provide low frequency magnetic fields pulse with the intensity from 150mT to 800mT and the frequency from 0 to 100Hz. This device is easy to operate and performs reliably. It can stably work for a long time and has been successful used in the experiment of magnetic biological effect.

Specific p53 gene mutations in urinary bladder epithelium after the Chernobyl accident

After the Chernobyl accident, the incidence of urinary bladder cancers in the Ukraine population increased gradually from 26.2 to 36.1 per 100,000 between 1986 and 1996. Urinary bladder epithelium biopsied from 45 male patients with benign prostatic hyperplasia living in radiocontaminated areas of Ukraine demonstrated frequent severe urothelial dysplasia, carcinoma in situ, and a single invasive transitional cell carcinoma, combined with irradiation cystitis in 42 cases (93%). No neoplastic changes (carcinoma in situ or transitional cell carcinoma) were found in 10 patients from clean areas (areas without radiocontamination). DNA was extracted from the altered urothelium of selected paraffin-embedded specimens that showed obviously abnormal histology (3 cases) or intense p53 immunoreactivity (15 cases), and mutational analysis of exons 5-8 of the p53 gene was performed by PCR-single-strand conformational polymorphism analysis followed by DNA sequencing. Nine of 17 patients (53%) had one or more mutations in the altered urothelium. Urine sediment samples were also collected from the patients at 4-27 months after biopsy and analyzed by PCR-single-strand conformational polymorphism analysis or yeast functional assay, and identical or additional p53 mutations were found in four of five cases. Interestingly, a relative hot spot at codon 245 was found in five of nine (56%) cases with mutations, and 11 of the 13 mutations determined (73%) were G:C to A:T transitions at CpG dinucleotides, reported to be relatively infrequent (approximately 18%) in human urinary bladder cancers. Therefore, the frequent and specific p53 mutations found in these male patients may alert us to a future elevated occurrence of urinary bladder cancers in the radiocontaminated areas.

[Expression of vascular endothelial growth factor and tumor angiogenesis correlates with biological behaviors of nasopharyngeal carcinoma]

OBJECTIVE

To study the correlation between tumor angiogenesis and biological behaviors of nasopharyngeal carcinoma(NPC).

METHOD

Angiogenesis was assessed by the microvessel dinsity(MVD) and expression of vascular endothelial growth factor(VEGF) was detected using immunohistochemical S-P method. Paraffin-embedded specimens from 65 patients with NPC and 15 with benign nasopharyngeal tumors, 15 with tumor-free nasopharyngeal mucosac were detected.

RESULT

Expressions of VEGF and MVD in NPC group were higher than that of nonmetastic carcinoma group. The relationship between expressions of VEGF and MVD and the clinical staging present statistic significance.

CONCLUSION

MVD and expression of VEGF are highly correlated with biological behaviors of NPC, which may serve as a parameter for determining tumor biological metastatic potential and prognosis. Angiogenesis inhibitors might be helpful in preventing NPC from metastasis.

[The clinical significance of preserving superior epigastric vessels in Cohen incision]

OBJECTIVE

To study the clinical significance of preserving epigastric vessels in Cohen incision.

METHODS

42 cases of pregnant women were performed cesarean section using Cohen incision. One side vessel of incision was preserved, the other side was cut off. By self control comparison, skin temperature of two sides incision has been taken by CET (computer electric infrared thermograph) on the third day post operation. The thinkness of scar was measured with vernier calipers on the 40th day post operation.

RESULTS

The skin temperature difference between both sides of incision was (0.098 +/- 0.088) degree C. On the cut side the skin temperature was higher than that of the other side (P < 0.01). The scar thickness of cut side was (3.61 +/- 0.61) mm, the other side was (3.10 +/- 0.68) mm. The difference was significant (P < 0.01).

CONCLUSION

The inflammatory reaction and formation of scar can be decreased by means of preserving superior epigastric vessels in Cohen incision.