Expression of endothelial nitric oxide synthase traffic inducer in the placentas of women with pre-eclampsia

OBJECTIVE

To investigate the expression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) in the placenta of women with pre-eclampsia (PE) and discuss its role in the pathogenesis of PE.

METHODS

Western blot analysis was used to detect the expression of NOSTRIN and endothelial nitric oxide synthase (eNOS). The activity of eNOS in placental tissue was assayed by spectrophotometry. Serum and placental NO(2)/NO(3), the stable metabolic end product of NO, was measured using nitrate reductase.

RESULTS

Western blot analysis showed that the protein level of NOSTRIN was significantly higher in women with PE than in the control group (P<0.01). However, no significant difference between groups was observed in the expression of placental eNOS (P>0.05). The activity of eNOS was significantly decreased in women with PE (13.727+/-3.58 U/mg) compared with the control group (21.69+/-3.84 U/mg) (P<0.01). The placental levels of NO(2)/NO(3) were significantly lower in women with PE (27.53+/-8.51 micromol/mg) than in the control group (44.38+/-9.59 micromol/mg) (P<0.01). The levels of serum NO(2)/NO(3) were significantly lower in women with PE (48.56+/-8.49 micromol/L) than in the control group (65.37+/-9.61 micromol/L) (P<0.01). A significant negative correlation existed between the expression of NOSTRIN protein and the activity of eNOS in the placental tissues of women with PE (r=-0.57, P<0.01).

CONCLUSION

The level of NOSTRIN expression in the placental tissues of women with PE is increased and is negatively correlated with the activity of eNOS-which may play an important role in the pathogenesis of PE.

Development and psychometric tests of the Chinese-version Low Vision Quality of Life Questionnaire

BACKGROUND/AIMS

To develop and assess the psychometric validity of a Chinese language Vision Health related quality-of-life (VRQoL) measurement instrument for the Chinese visually impaired.

METHODS

The Low Vision Quality of Life Questionnaire (LVQOL) was translated and adapted into the Chinese-version Low Vision Quality of Life Questionnaire (CLVQOL). The CLVQOL was completed by 100 randomly selected people with low vision (primary group) and 100 people with normal vision (control group). Ninety-four participants from the primary group completed the CLVQOL a second time 2 weeks later (test-retest group). The internal consistency reliability, test-retest reliability, item-internal consistency, item-discrimination validity, construct validity and discriminatory power of the CLVQOL were calculated.

RESULTS

The review committee agreed that the CLVQOL replicated the meaning of the LVQOL and was sensitive to cultural differences. The Cronbach's alpha coefficient and the split-half coefficient for the four scales and total CLVQOL scales were 0.75-0.97. The test-retest reliability as estimated by the intraclass correlations coefficient was 0.69-0.95. Item-internal consistency was > 0.4 and item-discrimination validity was generally < 0.40. The Varimax rotation factor analysis of the CLVQOL identified four principal factors. the quality-of-life rating of four subscales and the total score of the CLVQOL of the primary group were lower than those of the Control group, both in hospital-based subjects and community-based subjects.

CONCLUSION

The CLVQOL Chinese is a culturally specific vision-related quality-of-life measure instrument. It satisfies conventional psychometric criteria, discriminates visually healthy populations from low vision patients and may be valuable in screening the local community as well as for use in clinical practice or research.

Molecular pharmacology of the interaction of anthracyclines with iron

Although anthracyclines such as doxorubicin are widely used antitumor agents, a major limitation for their use is the development of cardiomyopathy at high cumulative doses. This severe adverse side effect may be due to interactions with cellular iron metabolism, because iron loading promotes anthracycline-induced cell damage. On the other hand, anthracycline-induced cardiotoxicity is significantly alleviated by iron chelators (e.g., desferrioxamine and dexrazoxane). The molecular mechanisms by which anthracyclines interfere with cellular iron trafficking are complex and still unclear. Doxorubicin can directly bind iron and can perturb iron metabolism by interacting with multiple molecular targets, including the iron regulatory proteins (IRP) 1 and 2. The RNA-binding activity of these molecules regulates synthesis of the transferrin receptor 1 and ferritin, which are crucial proteins involved in iron uptake and storage, respectively. At present, it is not clear whether doxorubicin affects IRP1-RNA-binding activity by intracellular formation of doxorubicinol and/or by generation of the doxorubicin-iron(III) complex. Furthermore, doxorubicin prevents the mobilization of iron from ferritin by a mechanism that may involve lysosomal degradation of this protein. Prevention of iron mobilization from ferritin would probably disturb vital cellular functions as a result of inhibition of essential iron-dependent proteins, such as ribonucleotide reductase. This review discusses the molecular interactions of anthracyclines with iron metabolism and the development of cardioprotective strategies such as iron chelators.

Strong Green Emission from α-SiAlON Activated by Divalent Ytterbium under Blue Light Irradiation

This contribution reports on luminescence properties of divalent ytterbium in alpha-SiAlON at room temperature. Ytterbium-doped alpha-SiAlON powders, with the compositions of (M(1-2x/v)Yb(x))(m/v)Si(12-m-n)Al(m+n)O(n)N(16-n) (M = Ca, Li, Mg, and Y, v is the valency of M, 0.002 < or = x < or = 0.10, 0.5 < or = m = 2n < or = 3.5), were synthesized by sintering at 1700 degrees C for 2 h under 0.5 MPa N2. A single, intense, broad emission band, centered at 549 nm, is observed due to the electronic transitions from the excited state 4f(13)5d to the ground state 4f14 of Yb2+. The luminescence of Yb2+ in alpha-SiAlON occurs at relatively low energy, which is attributable to the large crystal field splitting and nephelauxetic effect due to the nitrogen-rich coordination of Yb2+. The dependence of luminescence properties on the Yb2+ concentration, chemical composition, and annealing is discussed. It is suggested that this novel green phosphor could be applied in white light-emitting diodes (LEDs) when combined with a red phosphor and a blue LED.

Effects of vasopressin and long pulse-low frequency gastric electrical stimulation on gastric emptying, gastric and intestinal myoelectrical activity and symptoms in dogs

The aim of this study was to investigate the effect of vasopressin and long pulse-low frequency gastric electrical stimulation (GES) on gastric emptying, gastric and intestinal myoelectrical activity and symptoms in dogs. The study was performed in eight healthy female dogs implanted with four pairs of gastric serosal electrodes and two pairs of small bowel serosal electrodes, and a duodenal fistula for the assessment of gastric emptying. Each dog was studied in three sessions on three separate days in a randomized order with recordings of gastric and small bowel slow waves. Each study session consisted of 30-min baseline, 30-min stimulation and 30-min recovery period. In sessions 1 and 2, infusion of either saline or vasopressin (0.75 U kg(-1) in 30 mL saline instilled in 30 min) was given during the second 30-min period. The protocol of session 3 was the same as session 2 except long pulse-low frequency GES was performed during the second 30-min period. It was found that: (i) Vasopressin significantly delayed gastric emptying 30 and 45 min after meal and GES did not improve the vasopressin induced delayed gastric emptying; (ii) Vasopressin induced gastric dysrhythmias and GES significantly improved vasopressin induced gastric dysrhythmia; (iii) Vasopressin also induced intestinal slow wave abnormalities but GES had no effect on vasopressin induced small bowel dysrhythmia; (iv) Vasopressin induced symptoms and behaviours suggestive of nausea that were not improved by GES. We conclude that: (i) Vasopressin delays gastric emptying and induces gastric and small bowel dysrhythmias and symptoms in the fed state, and (ii) long pulse-low frequency GES normalizes vasopressin induced gastric dysrhythmia with no improvement in gastric emptying or symptoms.

Lymphatic vessel density is significantly increased in melanoma

BACKGROUND

Melanoma is well known for its ability to involve regional lymph nodes in the early stage. However, the presence of lymphangiogenesis in melanoma is still controversial due to lack of lymphatic-specific markers. The purpose of this study was to determine the intra- and peritumoral lymphatic vessel density (LVD) using a novel lymphatic vessel-specific marker D2-40 and compare it to general vessel density (GVD) as determined by CD31 immunostaining in a series of melanocytic lesions.

METHODS

The intra- and peritumoral GVD and LVD were examined by immunohistochemistry using D2-40 and CD31 antibodies in a series of melanocytic lesions.

RESULTS

We found significantly higher intratumoral LVD in melanomas as compared to either common acquired or dysplastic nevi (p < 0.01). Although peritumoral LVD in melanoma and malignant melanoma in situ was higher compared to nevi, the difference did not reach statistical significance (p = 0.059). There was no significant difference in GVD among the various groups of melanocytic lesions.

CONCLUSIONS

Our results show that intratumoral LVD is significantly increased in melanomas compared to benign nevi. The higher intratumoral lymphatic density in invasive melanomas suggests that melanoma cells might promote lymphangiogenesis. In addition, assessment of intratumoral LVD may be potentially useful in the differential diagnosis of melanocytic lesions.

SU proteins from virulent and avirulent EIAV demonstrate distinct biological properties

Biologic activity of equine infectious anemia virus (EIAV) surface (SU) glycoprotein was assayed in a mouse model. Recombinant SU from virulent EIAV17 (SU17), administered intraperitoneally to mouse pups, induced dose-dependent diarrheal responses similar to those reported for SIV SU (Virology 277 (2000) 250). SU17 caused fluid accumulation without histological lesions in mouse intestinal loops, induced chloride secretory currents in Ussing chambers and increased inositol 1,4,5 triphosphate (IP3) levels in HT29 cells. An SU17 peptide, SU17(299-330), provoked a dose-dependent diarrheal response akin to enterotoxic peptides from SIV. In contrast, SU from an avirulent EIAV strain failed to induce a dose response in mouse pups and produced lower levels of activity than SU17 in Ussing chambers and IP3 assays. These results demonstrate that a mouse pup model is useful to monitor EIAV SU biologic activity, showing clear differences between the activities of SU derived from virulent and avirulent viruses, and may provide a useful screen of EIAV virulence.

Stress and dysmenorrhoea: a population based prospective study

BACKGROUND

Dysmenorrhoea is the most common gynaecological disorder in women of reproductive age. Despite the association between stress and pregnancy outcomes, few studies have examined the possible link between stress and dysmenorrhoea.

AIMS AND METHODS

Using a population based cohort of Chinese women, the independent effect of women's perceived stress in the preceding menstrual cycle on the incidence of dysmenorrhoea in the subsequent cycle was investigated prospectively. The analysis included 1160 prospectively observed menstrual cycles from 388 healthy, nulliparous, newly married women who intended to conceive. The perception of stress and the occurrence of dysmenorrhoea in each menstrual cycle were determined from daily diaries recorded by the women.

RESULTS

After adjustment for important covariates, the risk of dysmenorrhoea was more than twice as great among women with high stress compared to those with low stress in the preceding cycle (OR = 2.4; 95% CI 1.4 to 4.3). The risk of dysmenorrhoea was greatest among women with both high stress and a history of dysmenorrhoea compared to women with low stress and no history of dysmenorrhoea (OR = 10.4, 95% CI 4.9 to 22.3). Stress in the follicular phase of the preceding cycles had a stronger association with dysmenorrhoea than stress in the luteal phase of the preceding cycles.

CONCLUSION

This study shows a significant association between stress and the incidence of dysmenorrhoea, which is even stronger among women with a history of dysmenorrhoea.

Prospective study of relationship between cytomegalovirus pneumonia and viral load in renal transplant recipients

The present study prospectively examined the relationship between cytomegalovirus interstitial pneumonia (CMV-IP) and viral load among 56 renal transplant recipients. We sought to identify the cutoff of viral load to predict CMV-IP. Blood samples were obtained weekly within the first 2 months and every second week during 2 to 6 months after kidney transplantations. A commercial real-time polymerase chain reaction (PCR)-method was applied to quantify CMV-DNA in plasma or in leukocytes. Among 54 renal transplant recipients who were analyzed for CMV-DNA in the blood (96.4%), 8 experienced CMV-IP (14.3%) and 2 died (3.6%). After kidney transplantation, CMV-DNA loads were near 0 in plasma before the week 4 and before the week 3 in leukocytes among both groups. From week 5 (week 4, in leukocytes), plasma CMV-DNA loads in the CMV-IP group increased, the peak value reached at week 8 in plasma and the week 9 in leukocytes. Whereas, the CMV-DNA loads both in plasma and in leukocytes in the non-CMV-IP group fluctuated at lower levels, those in plasma were significantly different between the 2 groups at the weeks 5, 7, and 9. For CMV-DNA in leukocytes, there were significant differences between 2 groups from week 6 to week 11. The present study demonstrated that dynamic determination of CMV-DNA may predict the occurrence of CMV-IP. Viral loads over 10(4) copies/mL plasma continuing for 3 weeks may serve as a cutoff to predict CMV-IP.

Beta-adrenoceptor subtype dependence of chronotropy in mouse embryonic stem cell-derived cardiomyocytes

Cardiomyocytes derived from embryonic stem cells (ESCM) have potential both as an experimental model for investigating cardiac physiology and as a source for tissue repair. For both reasons it is important to characterise the responses of these cells, and one of the key modulators of contraction is the beta-adrenergic system. We therefore undertook a detailed study of the response of the spontaneous beating rate of ESCM to beta-adrenoceptor (betaAR) stimulation. Embryoid bodies (EBs) were generated from murine ES line E14Tg2a by the hanging drop method, followed by plating. Spontaneously beating areas were seen starting from 9-14 days after differentiation: the experiments described here were performed on EBs between developmental day 19 and 48. Beating cell layers were seeded with charcoal to allow tracking of movement by a video-edge detection system. Experiments were performed in physiological medium containing 1 mM Ca2+ at 37 degrees C. Isoprenaline (Iso) increased beating rate with an EC50 value of 52 nM. Iso (0.3 microM) increased basal rate from 67 +/- 7 beats per minute (bpm) to 138 +/- 18 bpm, P < 0.001, n = 22. At earlier developmental time points the response to Iso was not maintained through 5 min exposure; this spontaneous desensitisation only being observed before day 36. A repeat application of Iso after a wash period of 20 min produced reproducible effects on beating rate. Subtype dependence of the betaAR response was determined by comparing an initial response with a second in the presence of selective beta1- or beta2AR antagonists. In the presence of the specific beta1AR-blocker CGP 20712A (300 nM) the increase in rate with Iso was reduced from 207 +/- 42% of basal to 128 +/- 13%, P < 0.01. With the beta2AR-blocker ICI 118,551 (50 nM) there was no significant change in Iso response. Exposure to the muscarinic agonist, carbachol (10 microM), inhibited the increase in frequency mediated by isoprenaline, but had mixed stimulatory and inhibitory effects on basal rate. This study extends the characterisation of ESCM as a preparation for studying receptor pharmacology, and indicates that the beta1AR is the predominant subtype mediating increases in contraction rate in murine ESCM.

Temperature-induced gelation of concentrated silicon carbide suspensions

Due to the steric barrier provided by the adsorption of the dispersant hypermer KD1 (a polyester/polyamine condensation polymer), stable and low-viscosity suspensions of SiC, Y(2)O(3), and Al(2)O(3) powder mixtures could be prepared in methyl ethyl ketone (MEK)/ethanol (E) solvent with solids loading as high as 60 vol%. The solvency of the dispersant in MEK/E decreased dramatically on cooling. Steady shear viscosity and oscillatory measurements were performed as a function of temperature for suspensions with different solids loading. The viscosity and elastic modulus of suspension increased with decreasing temperature and became more sensitive with the increase of solids loading. The suspensions with solids loading higher than 40 vol% could be solidified with decreasing temperature, but gelation temperature and gelation stiffness decreased with decreasing solids loading. The 60 vol% solid-loaded suspension was a stable and free-flowing fluid at 20 degrees C and gradually transformed to a very highly viscous and elastic system upon cooling to about 13 degrees C. Complete solidification occurred when the temperature was decreased to 5 degrees C. The gelation mechanism was mainly based on the collapse of the adsorbed layer as the temperature decreases, which induced incipient flocculation and formed a stiff network. The gelled body was further strengthened by separation of the dispersant from the suspension.

Defective Clearance of Adenovirus in IRF-1-/- Mice Associated with Defects in NK and T Cells but not Macrophages

A replication-defective adenovirus-LacZ recombinant virus (AdLacZ) was injected intravenously into IRF-1(-/-) mice and wild-type mice to characterize the contribution of IRF-1 to the immune-mediated clearance of Ad vector. Compared with wild-type mice, IRF-1(-/-) mice expressed higher levels of the LacZ gene product in the liver. After infusion of the AdLacZ, the expression of IRF-1 mRNA was upregulated in the liver of wild-type mice, but not in IRF-1(-/-) mice. Both spleen and liver mononuclear cells from IRF-1(-/-) mice initially exhibited a markedly lower number of NK, NK-T and CD8 T cells. At day 7 after the administration of AdLacZ, there was a significantly increased population of NK, NK-T and CD8 T cells in both spleen and liver, and also CD11b(+) cells in liver of IRF-1(-/-) mice, compared with the increased in wild-type mice. As IRF-1 is an important signal for production of IFN-gamma by CD8 T and NK cells as well as production of IL-12 by CD11b(+) cells, we determined whether there were lower levels of these cytokines in IRF-1(-/-) mice after Ad challenge. Surprisingly, there were lower levels of IL-12, but higher levels of IFN-gamma and IL-18 in IRF-1(-/-) compared with wild-type mice at day 7 after administration with AdLacZ. These results indicate that delayed clearance of Ad is associated with partial correction of defects of the NK, NK-T and CD8 T cells and increased production of IFN-gamma and IL-18 in IRF-1(-/-) mice.

Osteoblastic cells express phospholipid receptors and phosphatases and proliferate in response to sphingosine-1-phosphate

Sphingosine-1-phosphate (S1P) is a naturally occurring polar phospholipid that exerts growth-factor--like effects in a number of cell types, potentially by endocrine, paracrine, and intracrine mechanisms. The biological actions of S1P are mediated in part by its specific binding to at least four members of the edg/lp family of G protein-coupled receptors (edg 1, 3, 6, and 8), and further regulated by the actions of specific cell membrane-bound lipid phosphate phosphatases (LPPs). Recent evidence has suggested that S1P may act as an osteoblast growth factor. In the current study, we demonstrate expression in osteoblastic cells of the S1P receptors edg 1, edg 5 and edg 8; the lipid phosphate phosphatases LPP-1, LPP-2, and LPP-3, and the S1P phosphatase mSPP1. S1P exerts dose-dependent mitogenic effects in cultures of primary rat osteoblastic cells and SaOS-2 cells. S1P also activates p42/44 mitogen-activated protein (MAP) kinases in osteoblastic cells, and the proliferative effects of S1P in these cultures are partially abrogated by PD-98059 and U-0126, specific inhibitors of p42/44 MAP kinase signaling. S1P-induced p42/44 MAP kinase activation in osteoblastic cells is dependent on functional Gi proteins and intracellular calcium fluxes, but not on protein kinase A, phospha-tidylinositol-3 kinase, or protein Kinase C. These data demonstrate (1) the expression by osteoblastic cells of several cell membrane-bound components of phospholipid signaling and (2) that S1P is a potent osteoblast mitogen, the proliferative action of which is mediated by a signaling pathway that involves Gi proteins, intracellular calcium, and p42/44 MAP kinases.