The potential role for arachidonic and docosahexaenoic acids in protection against some central nervous system injuries in preterm infants

The risk of central nervous, visual, and auditory damage increases from 2/1000 live births in the normal birthweight to > 200/1000 as birthweight falls below 1500 g. Such babies are most likely to be born preterm. Advances in infant care have led to increasing numbers of very-low-birthweight, preterm infants surviving to school age with moderate to severe brain damage. Steroids are one of the current treatments, but they cause significant, long-term problems. The evidence reported here suggests an additional approach to protecting the very preterm infant by supporting neurovascular membrane integrity. The complications of preterm, very-low-birthweight babies include bronchopulmonary dysplasia, retinopathy of prematurity, intraventricular hemorrhage, periventricular leukomalacia, and necrotizing enterocolitis, all of which have a vascular component. Arachidonic acid (AA) and DHA are essential, structural, and functional constituents of cell membranes. They are especially required for the growth and function of the brain and vascular systems, which are the primary biofocus of human fetal growth. Molecular dynamics and experimental evidence suggest that DHA could be the ligand for the retinoid X receptor (RXR) in neural tissue. RXR activation is an obligatory step in signaling to the nucleus and in the regulation of gene expression. Very preterm babies are born with minimal fat stores and suboptimal circulating levels of these nutrients. Postnatally, they lose the biomagnification of the proportions of AA and DHA by the placenta for the fetus. No current nutritional management repairs these deficits. The placental biomagnification profile highlights AA rather than DHA. The resultant fetal FA profile closely resembles that of the vascular endothelium and not the brain. Without this nourishment, cell membrane abnormalities would be predicted. We present a scientific rationale for a common pathogenic process in the complications of prematurity.

On small-sample confidence intervals for parameters in discrete distributions

The traditional definition of a confidence interval requires the coverage probability at any value of the parameter to be at least the nominal confidence level. In constructing such intervals for parameters in discrete distributions, less conservative behavior results from inverting a single two-sided test than inverting two separate one-sided tests of half the nominal level each. We illustrate for a variety of discrete problems, including interval estimation of a binomial parameter, the difference and the ratio of two binomial parameters for independent samples, and the odds ratio.

A randomised multicentre phase II trial of capecitabine vs S-1 as first-line treatment in elderly patients with metastatic or recurrent unresectable gastric cancer

This randomised multicentre phase II study was conducted to investigate the activity and safety of two oral fluoropyrimidines, capecitabine or S-1, in elderly patients with advanced gastric cancer (AGC). Elderly (⩾65 years) chemo-naive patients with AGC were randomly assigned to receive capecitabine 1250 mg m⁻² two times daily on days 1–14 every 3 weeks or S-1 40–60 mg two times daily according to body surface area on days 1–28 every 6 weeks. Ninety-six patients were enrolled and 91 patients were randomised to capecitabine (N=46) or S-1 (N=45). Overall response rate, the primary end point, was 27.2% (95% CI, 14.1–40.4, 12 of 44 assessable patients) with capecitabine and 28.9% (95% CI, 15.6–42.1, 13 of 45) with S-1. Median times to progression and overall survival in the capecitabine arm (4.7 and 9.5 months, respectively) were similar to those in the S-1 arm (4.2 and 8.2 months, respectively). The incidence of grade 3–4 granulocytopenia was 6.8% with capecitabine and 4.8% with S-1. Grade 3–4 nonhaematologic toxicities were: asthenia (9.1% with capecitabine vs 7.1% with S-1), anorexia (6.8 vs 9.5%), diarrhoea (2.3 vs 0%), and hand–foot syndrome (6.8 vs 0%). Both capecitabine and S-1 monotherapies were active and tolerable as first-line treatment for elderly patients with AGC.

Insulin-like growth factor I receptor blockade enhances chemotherapy and radiation responses and inhibits tumour growth in human gastric cancer xenografts

BACKGROUND AND AIMS

Insulin-like growth factor (IGF) I receptor (IGF-Ir) signalling is required for carcinogenicity and proliferation of many tumours but this pathway has not been studied in detail in gastric cancer. We have previously shown successful therapy for colorectal, pancreatic, and lung cancer using recombinant adenoviruses expressing dominant negative (dn) IGF-Ir. In this study, we sought to better dissect the role of IGF-Ir on progression of gastric cancer and determine whether IGF-Ir targeted adenoviruses represent potentially effective therapeutics for human gastric cancer.

METHODS

We assessed the effect of IGF-Ir ligands on proliferation and survival in gastric cancer cells in culture. Then, recombinant adenoviruses expressing truncated IGF-Ir (482 and 950 amino acids long, IGF-Ir/dn) that function as dn inhibitors were studied in the treatment of human gastric cancer xenografts. We characterised the effects of IGF-Ir/dn on signalling blockade, growth, apoptosis induction, and in vivo therapeutic efficacy.

RESULTS

IGF-Ir signalling promoted tumour growth and survival in gastric cancer. IGF-Ir/dn expression suppressed tumorigenicity both in vitro and in vivo and upregulated stressor induced apoptosis. IGF-Ir/dn blocked Akt-1 activation induced by IGF-I, IGF-II, and des(1-3)IGF-I, but not by insulin. IGF-Ir/dn expression increased radiation and chemotherapy induced apoptosis and the combination of IGF-Ir/dn and chemotherapy was very effective against tumours in mice. In an intraperitoneal model, IGF-Ir/dn therapy also suppressed peritoneal dissemination.

CONCLUSIONS

IGF-Ir is involved in the regulation of survival and cell growth in human gastric cancer and may be a good molecular therapeutic target. Adenovirus-IGF-Ir/dn may thus have therapeutic use in gastric cancer.

Adverse effect of obesity on red cell membrane arachidonic and docosahexaenoic acids in gestational diabetes

AIMS/HYPOTHESIS

Gestational diabetes is a metabolic disorder affecting 2-5% of women and is a predictor of obesity, Type 2 diabetes mellitus and cardiovascular disease. Insulin resistance, a characteristic of gestational diabetes and obesity, is correlated with the fatty acids profile of the red cell and skeletal muscle membranes. We investigated the plasma and red cell fatty acid status of gestational diabetes. The effect of obesity on membrane fatty acids was also examined.

METHODS

Fasting blood obtained at diagnosis was analysed for the fatty acids in plasma choline phosphoglycerides and red cell choline and ethanolamine phosphoglycerides.

RESULTS

There were reductions in arachidonic acid (controls 10.74+/-2.35 vs gestational diabetes 8.35+/-3.49, p<0.01) and docosahexaenoic acid (controls 6.31+/-2.67 vs gestational diabetes 3.25+/-2.00, p<0.0001) in the red cell choline phosphoglycerides in gestational diabetes. A similar pattern was found in the ethanolamine phosphoglycerides. Moreover, the arachidonic and docosahexaenoic acids depletion in the red cell choline phosphoglycerides was much greater in overweight/obese gestational diabetes (arachidonic acid=7.49+/-3.37, docosahexaenoic acid=2.98+/-2.18, p<0.01) compared with lean gestational diabetes (arachidonic acid=10.03+/-2.74, docosahexaenoic acid=4.18+/-1.42).

CONCLUSION/INTERPRETATION

Apparently normal plasma choline phosphoglycerides fatty acids profile in the gestational diabetic women suggested that membrane lipid abnormality is associated specifically with perturbation in the membrane. The fact that the lipid abnormality is more pronounced in the outer leaflet of the membrane where most of receptor binding and enzyme activities take place might provide an explanation for the increased insulin resistance in gestational diabetes and obesity.

Identification of genes differentially expressed in association with acquired cisplatin resistance

The goal of this study was to identify genes whose mRNA levels are differentially expressed in human cells with acquired cisplatin (cDDP) resistance. Using the parental UMSCC10b head and neck carcinoma cell line and the 5.9-fold cDDP-resistant subline, UMSCC10b/Pt-S15, two suppressive subtraction hybridization (SSH) cDNA libraries were prepared. One library represented mRNAs whose levels were increased in the cDDP resistant variant (the UP library), the other one represented mRNAs whose levels were decreased in the resistant cells (the DOWN library). Arrays constructed with inserts recovered from these libraries were hybridized with SSH products to identify truly differentially expressed elements. A total of 51 cDNA fragments present in the UP library and 16 in the DOWN library met the criteria established for differential expression. The sequences of 87% of these cDNA fragments were identified in Genbank. Among the mRNAs in the UP library that were frequently isolated and that showed high levels of differential expression were cytochrome oxidase I, ribosomal protein 28S, elongation factor 1alpha, alpha-enolase, stathmin, and HSP70. The approach taken in this study permitted identification of many genes never before linked to the cDDP-resistant phenotype.

Blood fatty acid composition of pregnant and nonpregnant Korean women: red cells may act as a reservoir of arachidonic acid and docosahexaenoic acid for utilization by the developing fetus

Relative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides (EPG) of pregnant (n = 40) and nonpregnant, nonlactating (n = 40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P < 0.05) and palmitic and oleic acids higher (P < 0.0001) in plasma CPG of the pregnant women. Similarly, the RBC CPG and EPG of the pregnant women had lower AA and DHA (P < 0.05) and higher palmitic and oleic acids (P < 0.01). The reduction in DHA and total n-3 fatty acids in plasma CPG of the pregnant women was paralleled by an increase in docosatetraenoic (DTA) and docosapentaenoic (DPA) acids of the n-6 series and in DPA/DTA ratio. In the RBC phospholipids (CPG and EPG) of the pregnant women, DTA and DPA acids of the n-6 series and DPA/DTA ratio did not increase with the decrease of the n-3 metabolites (eicosapentaenoic acid, DPA, and DHA) and total n-3. Since pregnancy was the main identifiable variable between the two groups, the lower levels of AA and DHA in RBC CPG and EPG of the pregnant women suggest that the mothers were mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation to the placenta to be utilized by the developing fetus.

Shikonin inhibits tumor invasion via down-regulation of NF-κB-mediated MMP-9 expression in human ACC-M cells

OBJECTIVE

The aim of this study was to examine the anti-invasion effect of Shikonin on human high-metastatic adenoid cystic carcinoma (ACC-M) cells and to explain the possible molecular mechanism involved.

METHODS

The ACC-M cells were treated with Shikonin (0, 2.5, 5, 10 μM) for 24 h. The protein levels and gelatinolytic activities of MMP-2 and MMP-9 were analyzed using Western blot and Gelatin zymography test, respectively. Matrigel invasion assays were used to investigate tumor invasive potential and electromobility shift assays were used to determine the activity of NF-κB.

RESULTS

The invasiveness of ACC-M cells was reduced in a dose dependent manner following 24-h treatment of up to 10 μM of the Shikonin at which concentration no cytotoxicity occurred. The protein levels and gelatinolytic activities of MMP-9 were significantly suppressed by increasing Shikonin concentrations. The down-regulation of MMP-9 appeared to be via the inactivation of NF-κB as the treatment with Shikonin suppressed the protein level of phosphate-IkBa, which was accompanied by a decrease in DNA-binding level of the factor.

CONCLUSIONS

Shikonin inhibits tumor invasion via downregulation of MMP-9 expression in ACC-M cells. Pharmacologic inhibition of the NF-κB-mediated MMP-9 expression by Shikonin might be a powerful treatment option for ACC patients in future.

Prevalence and Risk Factors of Gallbladder Polypoid Lesions in a Healthy Population

PURPOSE

To determine the prevalence of and investigate the risk factors for gallbladder (GB) polypoid lesions in a healthy population.

MATERIALS AND METHODS

A total of 23827 subjects who underwent abdominal ultrasonography in conjunction with health screening examinations were retrospectively analyzed. The prevalence of risk factors for GB polypoid lesions were evaluated. In addition, risk factors according to the number of polypoid lesions and the presence of stones with polypoid lesions were investigated. To analyze these risk factors, a control group was established with a 1:2 ratio matched for age and sex.

RESULTS

The prevalence of GB polypoid lesions was identified as 9.96%. On multivariate analysis, chronic hepatitis B infection (CHB) and the presence of metabolic syndrome (MS) were risk factors for GB polypoid lesions. CHB and MS were also significant independent risk factors for multiple GB polypoid lesions when compared with solitary GB polypoid lesions. In addition, gastric Helicobacter pylori infection and MS were significant risk factors for GB polypoid lesions with stones when compared with GB polypoid lesions without stones.

CONCLUSION

The prevalence of GB polypoid lesions in a healthy Korean population was 9.96%. Patients with CHB and MS need to be carefully examined for such lesions.

Adjuvant chemotherapy for gastric cancer: a randomised phase 3 trial of mitomycin-C plus either short-term doxifluridine or long-term doxifluridine plus cisplatin after curative D2 gastrectomy (AMC0201)

BACKGROUND

This phase 3 study evaluated the efficacy of new adjuvant chemotherapy (MFP), which intensified the mitomycin-C (MMC) plus short-term doxifluridine (Mf) for gastric cancer.

PATIENTS AND METHODS

A total of 855 patients (424 in Mf, 431 in MFP) with pathological stage II-IV (M0) gastric cancer after D2 gastrectomy were randomly assigned to receive either Mf (MMC 20 mg m(-2), followed by oral doxifluridine 460-600 mg m(-2) per day for 3 months) or MFP (MMC 20 mg m(-2), followed by oral doxifluridine 460-600 mg m(-2) per day for 12 months with 6 monthly infusions of 60 mg m(-2) of cisplatin) chemotherapy.

RESULTS

With a median follow-up of 6.6 years, there was no difference between the two groups in recurrence-free survival (RFS) (5-year RFS 61.1% in Mf and 57.9% in MFP; hazard ratio 1.10 (95% CI 0.89-1.35); P=0.39) and overall survival (OS) (5-year OS 66.5% in Mf and 65.0% in MFP; hazard ratio 1.11 (95% CI 0.89-1.39); P=0.33).

CONCLUSION

Intensification of Mf adjuvant chemotherapy by prolonging the duration of oral fluoropyrimidine and adding cisplatin was safe but not effective to improve the survivals in curatively resected gastric cancer patients.

Milk of northern Sudanese mothers whose traditional diet is high in carbohydrate contains low docosahexaenoic acid

AIM

  The suckling neonates and infants are reliant primarily on the mother for optimal supply of docosahexaenoic acid (DHA). The richest source of preformed DHA is cold-water oily fish. Although there is paucity of data, existing evidence suggest women with restricted access to these foods have low or marginal DHA status. The aim of the study was to investigate milk fatty acids of Sudanese mothers whose traditional diet is high in carbohydrate and low in fat and gain some insight into the provision of DHA to the suckling offspring.

METHODS

Colostrum (n =26), transitional (n=20) and mature (n=14) milk samples were obtained from Northern Sudanese women (NSW) recruited prior to delivery from Ibrahim Malik and Khartoum Teaching Hospitals.

RESULTS

  The arachidonic acid content of the colostrum (0.87±0.28%) and transitional (0.89± 0.29%) and mature (0.48±0.12%) milk of the NSW were broadly comparable with published international values. In contrast, the DHA level (colostrum 0.13±0.07%, transitional 0.13±0.06% and mature milk 0.06±0.05%) was very low.

CONCLUSION

  The study reveals breast milk of NSW, whose traditional diet is almost devoid of fish and fish products, is unlikely to provide sufficient DHA to support optimal postnatal neuro-visual development.

Plasma AA and DHA levels are not compromised in newly diagnosed gestational diabetic women

OBJECTIVE

The polyunsaturated fatty acids, arachidonic (AA) and docosahexaenoic (DHA), are vital structural and functional components of the neural, vascular and visual systems. There is increased demand for these fatty acids during pregnancy. Diabetes impairs the synthesis of both AA and DHA. We have investigated the possibility that pregnancy-induced diabetes compromises the levels of plasma AA and DHA in newly diagnosed expectant mothers.

DESIGN

Cross-sectional study.

SETTING

London, UK.

SUBJECTS AND METHODS

Venous blood was obtained from 44 women with gestational diabetes mellitus (GDM) and from the same number of nondiabetics, during the third trimester. Fatty acid composition of plasma choline phosphoglycerides (CPG), triglycerides (TG) and cholesterol esters (CE) was analysed.

RESULTS

The GDM women had higher levels of AA (20:4n-6; P<0.0001) and AA/linoleic acid ratio (20:4n-6/18:2n-6; P<0.01) in the CPG, and linoleic acid (LA; P<0.0001), total n-6 (P<0.01), DHA (P<0.05) and n-3 metabolites (P<0.05) in TG compared to their nondiabetic counterparts. Similarly, AA (P<0.0001), osbond acid (22:5n-6; P<0.05), total n-6 metabolites (P<0.0001), AA/LA (P<0.0001) and n-6 metabolites/LA (P<0.01) were higher in the CE of the GDM women. There was no difference in the levels of DHA in CPG and CE between the two groups (P>0.05).

CONCLUSIONS

The results of this study do not provide evidence that the activity of delta-6 or delta-5 desaturases, which are vital for the synthesis of AA and DHA, is compromised by pregnancy-induced diabetes. However, since the samples were taken at diagnosis, it is conceivable that the duration of the diabetes was too short to have a discernable adverse effect on the levels of AA and DHA in plasma lipids.

Construction and validation of a nomogram for predicting cervical lymph node metastasis in classic papillary thyroid carcinoma

PURPOSE

Patients with papillary thyroid carcinoma (PTC) frequently present a relatively poor prognosis when they coexist with cervical lymph node metastasis (LNM). Moreover, it remains controversial whether prophylactic lymph node dissection (LND) should be performed for patients without clinically lymph node metastasis. Thus, we hereby develop a nomogram for predicting the cervical LNM (including central and lateral LNM) in patients with PTC.

METHODS

We retrospectively reviewed the clinical characteristics of adult patients with PTC in the surveillance, epidemiology, and end results (SEER) database between 2010 and 2015 and in our Department of Breast and Thyroid Surgery in the Second Affiliated Hospital of Chongqing Medical University between 2019 and 2020.

RESULT

A total of 21,972 patients in the SEER database and 747 patients in our department who met the inclusion criteria were enrolled in this study. Ultimately, six clinical features including age, gender, race, extrathyroidal invasion, multifocality, and tumor size were identified to be associated with cervical LNM in patients with PTC, which were screened to develop a nomogram. This model had satisfied discrimination with a concordance index (C-index) of 0.733, supported by both internal and external validation with a C-index of 0.731 and 0.716, respectively. A decision curve analysis was subsequently made to evaluate the feasibility of this nomogram for predicting cervical LNM. Besides, a positive correlation between nomogram score and the average number of lymph node metastases was observed in all groups.

CONCLUSION

This visualized multipopulational-based nomogram model was successfully established. We determined that various clinical characteristics were significantly associated with cervical LNM, which would be better helping clinicians make individualized clinical decisions for PTC patients.

Fetal erythrocyte membrane lipids modification: preliminary observation of an early sign of compromised insulin sensitivity in offspring of gestational diabetic women

AIMS

Intrauterine exposure to diabetes is a significant determinant of the development of obesity and early onset of Type 2 diabetes mellitus in the offspring. Both conditions are characterized by insulin resistance and the latter is associated with reduced membrane arachidonic and docosahexaenoic acids. Hence, we investigated if the membrane arachidonic and docosahexaenoic acids are depressed in the cord blood of babies born to women with gestational diabetes.

METHODS

Cord (fetal) and maternal blood were obtained at delivery from control subjects (n = 33) and women with gestational diabetes (n = 40) and analysed for plasma triglycerides and cholinephosphoglycerides, and erythrocyte choline- and ethanolaminephosphoglycerides fatty acids.

RESULTS

Babies of gestational diabetic mothers had reduced docosahexaenoic acid in the plasma (5.9 +/- 1.4 vs. 7.1 +/- 2.0, P < 0.01) and erythrocyte (4.0 +/- 2.2 vs. 5.4 +/- 2.9, P < 0.05) cholinephosphoglycerides. Moreover, the total omega-6 and omega-3 fatty acids of the erythrocyte cholinephosphoglycerides were significantly lower (P < 0.05) in these babies. A similar trend was observed in plasma triglycerides and erythrocyte ethanolaminephosphoglycerides. The maternal plasma triglycerides and erythrocyte ethanolaminephosphoglycerides fatty acids profile were not different between the two groups. However, there was a reduction in arachidonic acid and total omega-6 fatty acids in the erythrocyte cholinephosphoglycerides of the gestational diabetic women.

CONCLUSION

The altered plasma and erythrocyte fatty acids in the cord blood of babies born to women with gestational diabetes suggests a perturbation in the maternal-fetal nutrient transport and/or fetal lipid metabolism.

Photoluminescence Properties of Surface-Modified Nanocrystalline ZnS : Mn

DBS surface-modified nanocrystalline ZnS : Mn was prepared by a precipitation method. Photoluminescence spectra and decay curves were measured and compared to those of unmodified samples. For both kinds of samples, luminescence decay curves of 600 nm emission consist of two components with nanosecond (ns) and millisecond (ms) lifetimes. The nanosecond component is attributed to zinc vacancies luminescence, with peak located at 440 nm. While the millisecond component is attributed to Mn(2+) luminescence and its decay time changes with Mn(2+) concentration and surface modification. The surface-modified sample has a longer lifetime compared to unmodified samples. The photoaging of surface-modified samples is slow. Particle size effects on photoaging were also examined. For nanocrystalline ZnS : Mn photoaging is more noticeable than that of bulk material. After UV irradiation, photoluminescence intensity of the modified sample is several times larger than that of the unmodified sample, because the surface-active reagent decreases surface defects and depresses radiationless transitions. XPS yields direct evidence of the surface-modification effect on the surface structure. Copyright 2000 Academic Press.

Association of matrilysin mRNA expression with K-ras mutations and progression in pancreatic ductal adenocarcinomas

The matrix metalloproteinase matrilysin has been implicated in the progression of gastrointestinal and other cancers. The aim of this study was to examine matrilysin mRNA expression and determine whether it is correlated with K-ras mutations and/or progression of pancreatic carcinoma. Using the semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we analyzed 11 pancreatic cancer cell lines and 70 pancreatic adenocarcinoma tissues for matrilysin mRNA expression. The results were correlated with clinicopathological characteristics and K-ras mutations. Significant amounts of matrilysin mRNA were detected in six of the eight cell lines with K-ras mutations but not in the three cell lines with wild-type K-ras. Matrilysin mRNA was detected in 57 (81.4% ) of the 70 tumor tissues and in all of the eight liver metastases, but not in any of the adjacent non-tumorous tissues. Matrilysin expression was significantly correlated with the size of tumor, tumor spreading, lymph node metastasis, advanced pathologic tumor-node- metastasis stage and K-ras mutations. The relative amounts of matrilysin mRNA in tumor tissues increased with increase in tumor stage and were highest in liver metastatic tumor tissues. Our results suggest that matrilysin, the expression of which is correlated with K-ras mutations, plays a key role in tumor growth and progression of pancreatic carcinoma.

Thrombin-reduced miR-27b attenuates platelet angiogenic activities in vitro via enhancing platelet synthesis of anti-angiogenic thrombospondin-1

Essentials It is unclear if platelet micro-RNAs can regulate de novo protein synthesis of platelets. Platelet de novo protein synthesis of thrombospondin-1 (TSP-1) was induced by thrombin. Thrombin stimulation in vitro altered platelet microRNA profiles, including decreased miR-27b. Decreased miR-27b hampers platelet angiogenic activities via enhancing de novo TSP-1 synthesis.

SUMMARY

Background Platelets can synthesize proteins upon activation. Platelets contain a number of microRNAs (miRNA) and a fully functional miRNA effector machinery. It is, however, unclear if platelet miRNAs can regulate protein synthesis of platelets, and whether the regulation may produce a physiological impact. Objectives To investigate if and how platelet miRNAs regulate de novo syntheses of angiogenic regulators and subsequently modulate platelet angiogenic activities. Methods and Results Microarray-based miRNA profiling showed that thrombin stimulation in vitro down- or up-regulated a number of platelet miRNAs, both in the total platelet miRNAs and in Ago2-associated miRNAs. Among those altered miRNAs, miR-27b was down-regulated in both the total and Ago2-immunoprecipitated miRNA profiles of platelets, which was confirmed by reverse transcription-quantitative PCR (RT-qPCR). Using western blotting assays, we showed that thrombin induced platelet de novo synthesis of thrombospondin-1, and that the level of thrombospondin-1 synthesis could reach a level of 3-5-fold higher than that before thrombin stimulation. With either the platelet precursor megakaryocyte cell line MEG-01 cells or mature platelets, we demonstrated that transfection of miR-27b mimic, but not the negative control of miRNA mimic, markedly reduced thrombospondin-1 protein levels. The latter subsequently enhanced platelet-dependent endothelial tube formation on matrigel. Conclusions Thrombin stimulation in vitro reduces platelet miR-27b levels that may markedly enhance thrombin-evoked platelet de novo synthesis of thrombospondin-1. Elevation of platelet miR-27b by transfection inhibits thrombospondin-1 synthesis, and subsequently enhances platelet pro-angiogenic activities. Hence, platelet activation-dependent reduction of miR-27b levels may represent a novel negative regulatory mechanism of platelet angiogenic activities.

Observation of discrete quadratic solitons

Discrete solitons with two frequency components mutually locked by a quadratic nonlinearity have been observed for the first time. Optical experiments have been performed in arrays of coupled channel waveguides with tunable cascaded quadratic nonlinearity. The tunability was the prerequisite that soliton species with different topology could be identified in the same array. Moreover, soliton stability has been experimentally probed. Good agreement with theoretical predictions was found.

Arachidonic and docosahexaenoic acids are strongly associated in maternal and neonatal blood

BACKGROUND

The red cell membrane fatty acid composition has frequently been used as an index of essential fatty acid (EFA) nutrition. After birth there is a decline in plasma arachidonic acid (AA) and docosahexaenoic (DHA) acids in babies fed on conventional formula which contains only the parent linoleic and alpha-linolenic acids. In human studies, the red cell phosphoglyceride composition appears to be more constant than that of plasma. In infants fed fish oil without AA, the AA proportions fall in the plasma but much less so in the red cells. This result might be considered to mean that there is no need for preformed AA. On the other hand, in a study where the levels of AA fell there was reduction of infant growth. Indeed, where cell membrane composition does change there is often an associated alteration in physiological functions of membranes. We therefore felt it worth investigating the balance between AA and DHA in a physiological situation where plasma levels are known to change, namely in pregnancy.

PURPOSE

The aim of the study was to investigate a relationship between blood phosphoglyceride AA and DHA in pregnant women and neonates.

SUBJECTS

Health pregnant women from London, England (n=193) and their term babies (n=45); healthy pregnant women from Seoul, South Korea (n=40) and their term babies (n=40); and preterm neonates (n=72) from London.

METHOD

Blood samples were taken from British and Korean pregnant women during the third trimester, and from term and preterm babies at birth. These samples were taken for routine monitoring purposes in Korea and were a part of a study on pregnancy outcome for which ethical permission was granted from the East London and The City Health Authority and Lambeth, Southwark and Lewisham Health Authority. Approval was also obtained from the Ethical Committee of the Asan Medical Centre, Seoul, South Korea.

RESULTS

AA and DHA correlated in plasma choline phosphoglycerides (CPG) of the British mothers (r=0.52 P<0.0001). The correlation coefficients and significance were much stronger in the red cell CPG and even more so in the term and preterm infant red cell CPGs ( r=0.75, 0.80 and 0.88, respectively). Similarly, AA and DHA correlated in red cell CPGs of the Korean women and their term babies. There was also a significant relationship between the two fatty acids in red cell ethanolamine phosphoglycerides in the mothers and their babies. Both linoleic (LA) and alpha-linolenic acids (ALA) were inversely associated with AA and DHA in some of the phosphoglyceride fractions of the mothers and babies.

CONCLUSIONS

Although AA and DHA have different primary dietary origins, there were significant relationships between AA and DHA in the phosphoglycerides of the red cell membrane. This finding seems surprising if the red cell composition is determined by diet. These results suggest a physiological mechanism which attempts to maintain an appropriate balance between AA and DHA. It is plausible that there is an optimum balance between AA and DHA for membrane stability, deformability, enzyme and receptor function.

SPONSORSHIP

The British Diabetic Association, March of Dimes Birth Defects Foundation and The Christopher H.R. Reeves Charitable Trust. European Journal of Clinical Nutrition (2000) 54, 50-56

Effect of docosahexaenoic acid-enriched fish oil supplementation in pregnant women with Type 2 diabetes on membrane fatty acids and fetal body composition--double-blinded randomized placebo-controlled trial

AIMS

To test if docosahexaenoic acid-enriched fish oil supplementation rectifies red cell membrane lipid anomaly in pregnant women with Type 2 diabetes and their neonates, and alters fetal body composition.

METHODS

Women with Type 2 diabetes (n = 88; 41 fish oil, 47 placebo) and healthy women (n = 85; 45 fish oil, 40 placebo) were supplemented from the first trimester until delivery. Blood fatty acid composition, fetal biometric and neonatal anthropometric measurements were assessed.

RESULTS

A total of 117 women completed the trial. The women with Type 2 diabetes who took fish oil compared with those who received placebo had higher percentage of docosahexaenoic acid in red cell phosphatidylethanolamine in the third trimester (12.0% vs. 8.9%, P = 0.000) and at delivery (10.7% vs. 7.4%, P = 0.001). Similarly, the neonates of the women with Type 2 diabetes supplemented with the fish oil had increased docosahexaenoic acid in the red cell phosphatidylethanolamine (9.2% vs. 7.7%, P = 0.027) and plasma phosphatidylcholine (6.1% vs. 4.7%, P = 0.020). Docosahexaenoic acid-rich fish oil had no effect on the body composition of the fetus and neonates of the women with Type 2 diabetes.

CONCLUSIONS

A daily dose of 600 mg of docosahexaenoic acid was effective in ameliorating red cell membrane docosahexaenoic acid anomaly in pregnant women with Type 2 diabetes and neonates, and in preventing the decline of maternal docosahexaenoic acid during pregnancy. We suggest that the provision of docosahexaenoic acid supplement should be integrated in the antenatal care of pregnant women with Type 2 diabetes.

Pregnancy reduces arachidonic and docosahexaenoic in plasma triacylglycerols of Korean women

Plasma triacylglycerol (TG) fatty acid composition of healthy non-pregnant and non-lactating women, expectant mothers and their term neonates from Seoul, South Korea was investigated. They were ethnically homogeneous and the women had comparable age and parity. Blood samples were obtained at recruitment, third trimester and birth from the non-pregnant women, expectant mothers and neonates respectively. Percent levels of linoleic and arachidonic acids and n-6 metabolites and total n-6 were significantly lower in the pregnant women than in the non-pregnant (p < 0.0001). Similarly, there were lower levels of alpha-linolenic (p = 0.033), eicosapentaenoic and docosahexaenoic acids and n-3 metabolites and total n-3 (p < 0.0001) in the expectant mothers. Compared with their mothers, the neonates had higher proportions of dihomo-gamma-linolenic, arachidonic, docosatetraenoic and docosapentaenoic acids and n-6 metabolites (p < 0.0001) and lower linoleic acid (p < 0.0001). Of the n-3 series, alpha-linolenic acid was lower (p < 0.0001) and eicosapentaenoic, docosapentaenoic and docosahexaenoic acids and n-3 metabolites and total n-3 higher (p < 0.0001) in the neonates compared with their mothers. The study reveals that pregnancy is associated with a reduction in the relative levels of plasma triacylglycerol arachidonic and docosahexaenoic acids. Moreover, it indicates that the decline is a manifestation of selective transfer of these fatty acids to the developing fetus.

Gender-specific fatty acid profiles in platelet phosphatidyl-choline and -ethanolamine

Previous studies suggested that women synthesise docosahexaenoic acid (DHA) more efficiently from their precursors than men. This study investigated the relationship between diet, platelet phospholipids fatty acids and gender. Dietary intake and platelet phosphatidyl-choline (PC) and phosphatidylethanolamine (PE) fatty acids were determined in Caucasian 40 men and 34 women. Absolute and %energy intakes of arachidonic acid (AA), eicosapentaenoic acid (EPA), and DHA, and the ratios of total n-6/n-3 PUFA and linoleic/alpha-linolenic acids did not differ between the sexes. However, women had higher DHA in PC (1.19 vs 1.05 wt%, p<0.05) and PE (3.62 vs 3.21 wt%, p<0.05) than men. Also EPA (1.10 vs 0.93 wt%, p<0.05) was higher in women's PE. Conversely, men had elevated AA and total n-6 fatty acids in PC. The higher platelet DHA levels and lower platelet AA/EPA and AA/DHA ratios in women of child-bearing age compared with men, may lead to less platelet aggregation and vaso-occlusion.

A new method to induce molecular low bias negative differential resistance with multi-peaks

According to a first-principles study of the transport properties of two thiolated anthracene-9,10-diono molecules sandwiching ethyl, a new method to induce molecular low bias negative differential resistance with multi-peaks for strong n- or p-type molecules is proposed. The anthracene-9,10-diono molecule shows strong n-type characteristics when in contact with Au and Ag electrodes via a thiolate. The multiple negative differential resistance effect originated from the molecule-electrode couple is different between Ag and Au electrodes. Our investigations may promise potential for applications in molecular devices with low power dissipation and multifunction in the future.