Transfer of conjugated linoleic acid from sows to their offspring and its impact on the fatty acid profiles of plasma, muscle, and subcutaneous fat in piglets

This experiment was conducted to determine if CLA could be transferred from sows to their offspring through the umbilical cord or milk. Eighteen pregnant Dalland sows of mixed parity were used in a completely randomized block design based on parity and BW. The sows were allotted to 1 of 3 groups and fed diets containing 0, 0.5, or 1.0% CLA during the last 50 d of gestation and throughout a 26-d lactation (n = 6). Umbilical cord blood was sampled at parturition. Colostrum and milk were collected from each sow on d 2 and 15 after farrowing. Samples of blood, backfat, and the LM were obtained from piglets at 2 and 26 d of age. Sow reproductive performance and piglet growth were not altered by CLA supplementation during the late gestation and lactation periods. The CLA supplementation of sow diets had an impact on the fatty acid profiles in colostrum and milk. Dietary CLA increased the concentrations of total SFA (linear and quadratic, P < 0.01), but reduced the total MUFA in the colostrum (linear and quadratic, P < 0.01). Although dietary CLA increased the concentrations of total SFA (quadratic, P < 0.01), it had no influence on total MUFA concentrations in the milk. In addition, feeding sows diets supplemented with CLA resulted in increases (linear and quadratic, P < 0.01) in the CLA content of plasma, backfat, and the LM in their offspring. However, trans-10, cis-12-18:2, rather than cis-9, trans-11-18:2, was detected in the umbilical cord blood, which indicates that CLA may be transported from the sow to the fetus in an isomer-specific manner.

Propagation losses in undoped and n-doped polycrystalline silicon wire waveguides

Polycrystalline silicon (polySi) wire waveguides with width ranging from 200 to 500 nm are fabricated by solid-phase crystallization (SPC) of deposited amorphous silicon (a-Si) on SiO(2) at a maximum temperature of 1000 degrees C. The propagation loss at 1550 nm decreases from 13.0 to 9.8 dB/cm with the waveguide width shrinking from 500 to 300 nm while the 200-nm-wide waveguides exhibit quite large loss (>70 dB/cm) mainly due to the relatively rough sidewall of waveguides induced by the polySi dry etch. By modifying the process sequence, i.e., first patterning the a-Si layer into waveguides by dry etch and then SPC, the sidewall roughness is significantly improved but the polySi crystallinity is degraded, leading to 13.9 dB/cm loss in the 200-nm-wide waveguides while larger losses in the wider waveguides. Phosphorus implantation causes an additional loss in the polySi waveguides. The doping-induced optical loss increases relatively slowly with the phosphorus concentration increasing up to 1 x 10(18) cm(-3), whereas the 5 x 10(18) cm(-3) doped waveguides exhibit large loss due to the dominant free carrier absorption. For all undoped polySi waveguides, further 1-2 dB/cm loss reduction is obtained by a standard forming gas (10%H(2) + 90%N(2)) annealing owing to the hydrogen passivation of Si dangling bonds present in polySi waveguides, achieving the lowest loss of 7.9 dB/cm in the 300-nm-wide polySi waveguides. However, for the phosphorus doped polySi waveguides, the propagation loss is slightly increased by the forming gas annealing.

Polymorphisms in the ovine myostatin gene (MSTN) and their association with growth and carcass traits in New Zealand Romney sheep

Myostatin is a regulator of myogenesis and has been implicated in the regulation of adiposity and in controlling the structure and function of tendons. Polymerase Chain Reaction Single-Stranded Conformational Polymorphism (PCR-SSCP) analysis of intron-1 was used to identify five variants (designated A-E) of the myostatin gene (MSTN). The effect of this genetic variation on growth and carcass traits was investigated in 517 Romney male lambs from 17 sire-lines, born on a South Island New Zealand farm. General linear mixed effect models revealed that the presence of allele A in a lamb's genotype was associated with decreased leg, loin and total yield of lean meat, whereas the presence of allele B was associated with increased loin yield and proportion loin yield (loin yield divided by total yield expressed as percentage). The effect of the number of allele copies present was investigated, and it was found that the absence of A, or the presence of two copies of B, was associated with increased mean leg yield, loin yield and total yield. Two copies of B were also associated with a decrease in proportion of shoulder yield, whereas two copies of A were associated with a decrease in proportion of loin yield. Associations with allele C were not detected. No associations of MSTN variation with birth weight, weaning weight, pre-weaning growth rate, draft age and hot carcass weight (H-W) were detected. These results suggest that variation in ovine MSTN is associated with meat production, but not birth weight or growth rate in New Zealand Romney sheep.

Adjuvant chemotherapy in completely resected stage III-N2 non-small cell lung cancer

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Background: We evaluate effect of postoperative adjuvant chemotherapy on overall survival after complete resection of stage III-N2 non-small-cell lung cancer. Methods: From Jan.1999 to Dec. 2003, a total of 150 stage III-N2 non-small cell lung cancer patients randomly received four cycles of chemotherapy (NVB25mg/m2, D1,D5 or paclitaxel 175mg/m2, D1 / carboplatin AUC=5, D1) or observation after operation. Results: The median survival for the 150 patients was 879 days, with a 1-year survival rate of 81%, 3-year survival rate of 43%, and 5-year survival rate of 28%.There was significant difference in median survival between chemotherapy and control group (897 days vs 821 days p=0.04), and also there was significant difference in 5-year survival rate (30% vs 24% p<0.05). The most common site of recurrence was brain. 26% (39/150) of patients recurred in the brain as their first site, 22% (18/79) for chemotherapy group, 29% (21/71) for control group. The median survival time for brain metastasis patients between chemotherapy and control group is no difference (812 days vs 512 days, p=0.122), but there was significant difference in 2-year survival rate (66.71% vs 37.6% p<0.05). Conclusions: Postoperative adjuvant chemotherapy dose significantly improves median survival among completely resected stage III-N2 non-small-cell lung cancer patients, and significantly improves 5-year survival rate. It dose not decrease incidence of brain metastasis but postpone the time of brain metastasis in chemotherapy group.

No significant financial relationships to disclose.

A genetic variant of G6PC2 is associated with type 2 diabetes and fasting plasma glucose level in the Chinese population

AIMS/HYPOTHESIS

Single nucleotide polymorphisms (SNPs) in G6PC2 have been reported to be associated with fasting plasma glucose level in several populations of European descent. However, whether G6PC2 variants have a similar effect in other ethnic groups is unknown. The aim of this study was to investigate the effect of common variants of G6PC2 on type 2 diabetes and related clinical features in a Chinese population.

METHODS

We selected four SNPs, rs13387347, rs2232316, rs492594 and rs16856187, tagging all the common variants spanning the G6PC2 gene (r(2) >or= 0.8) based on HapMap Chinese data, and genotyped them in a group of 3,676 Shanghai Chinese individuals, comprising 1,876 cases and 1,800 controls.

RESULTS

Three SNPs were nominally associated with type 2 diabetes, with rs16856187 showing the strongest evidence for association (p = 0.0009, empirical p = 0.0047). Further conditional analysis revealed that the association signal arose from an individual SNP, rs16856187. This SNP was also associated with fasting plasma glucose level in participants with normal glucose regulation (p = 0.0002), with the fasting plasma glucose level observed to increase by 0.067 mmol/l with each copy of the rare C allele.

CONCLUSIONS/INTERPRETATION

In this study we identified a novel risk-conferring G6PC2 SNP for type 2 diabetes in a Chinese population and confirmed the previous finding that G6PC2 variants are associated with fasting plasma glucose concentration.

Influence of grape seed proanthocyanidin extract in broiler chickens: effect on chicken coccidiosis and antioxidant status

Grape seed proanthocyanidin extract (GSPE) has been widely used as a human food supplement for health promotion and disease prevention. However, there was little information regarding its application in animal nutrition. The aim of the current study is to determine the effect of GSPE at different concentrations on chicken performance, and the status of antioxidant/oxidant system after the Eimeria tenella infection. In the first experiment, GSPE incorporated in the diet at 5, 10, 20, 40, and 80 mg/kg significantly decreased mortality and increased weight gain after the E. tenella infection, and the protective effect of GSPE was dose-dependent. The lowest mortality and the greatest growth gains were recorded in the group of birds fed with GSPE between 10 to 20 mg/kg. In the second experiment, 12 mg/kg of GSPE supplementation in the diet significantly reduced the mortality and lesion scores in birds after the infection with 5 x 10(4) and 1 x 10(5) oocysts of E. tenella. The weight gains also improved significantly. After the oral infection with 5 x 10(4) and 1 x 10(5) of E. tenella, analysis of the status of antioxidant/oxidant system revealed that plasma NO increased significantly from 7.11 to 21.31 micromol/L, plasma superoxide dismutase (SOD) decreased from 126.55 to 111.14 U/mL, and malondiadehyde increased, suggesting oxidative stress was increased in circulation. However, supplementation of 12 mg/kg GSPE reduced the level of plasma NO from 21.31 to 14.73 micromol/L and increased plasma SOD activities from 111.14 to 133.27 U/mL. The effects of incorporation of GSPE into the poultry diet on the concentration of plasma NO, malondiadehyde, and SOD indicated that the lower concentration of dietary GSPE was able to restore the balance of antioxidant/oxidant system that was exerted by the oxidative stress after the parasite infection. The current results suggested GSPE can act as an antioxidant in diet to improve the performance of broiler chickens and remedy the clinical symptoms caused by the oxidative stress of E. tenella infection.

Cascade wide-angle Y-junction 1 x 16 optical power splitter based on silicon wire waveguides on silicon-on-insulator

A 1 x 16 optical power splitter with wide splitting angle, uniform outputs, and low excess loss is demonstrated. The 1 x 16 splitter comprising cascaded 1 x 2 splitters with arc-shaped branching waveguides is fabricated on the silicon-on-insulator (SOI) substrate. The gap between the branching waveguides is widened in a short propagation length such that influences of etch residues and air voids in the gap on the optical power uniformity are reduced significantly. The measured power uniformity of the 1 x 16 splitter is better than 0.3 dB at wavelength of 1550 nm.

Effective thermo-optical enhanced cross-ring resonator MZI interleavers on SOI

A cross-ring (CR-) Mach-Zehnder interferometer (MZI) interleaver structure has been proposed and fabricated. It uses an '8' shaped cross-ring resonator to replace the conventional circular ring resonator. Thus, the new structure can have the function of add-signal. Furthermore, a thermo-optical fine tuning has been applied, which improves the crosstalk performance from approximately -10 dB to approximately -20 dB with 9 V applied on the heater of the 3-dB directional coupler.

Improving coupling efficiency of fiber-waveguide coupling with a double-tip coupler

A double-tip coupler that comprises two inversely and laterally tapered waveguides is experimentally demonstrated for efficient light coupling between a fiber and a sub-micron silicon nitride waveguide. The coupling efficiency of the fabricated double-tip coupler can be improved by as much as over 2 dB per coupling facet, compared with that of a single-tip one with the same tip width of 180 nm. The effect of the gap width of the double tips on the coupling efficiency is studied both in experiment and simulation.

Modeling nitrogen and water management effects in a wheat-maize double-cropping system

Excessive N and water use in agriculture causes environmental degradation and can potentially jeopardize the sustainability of the system. A field study was conducted from 2000 to 2002 to study the effects of four N treatments (0, 100, 200, and 300 kg N ha(-1) per crop) on a wheat (Triticum aestivum L.) and maize (Zea mays L.) double cropping system under 70 +/- 15% field capacity in the North China Plain (NCP). The root zone water quality model (RZWQM), with the crop estimation through resource and environment synthesis (CERES) plant growth modules incorporated, was evaluated for its simulation of crop production, soil water, and N leaching in the double cropping system. Soil water content, biomass, and grain yield were better simulated with normalized root mean square errors (NRMSE, RMSE divided by mean observed value) from 0.11 to 0.15 than soil NO(3)-N and plant N uptake that had NRMSE from 0.19 to 0.43 across these treatments. The long-term simulation with historical weather data showed that, at 200 kg N ha(-1) per crop application rate, auto-irrigation triggered at 50% of the field capacity and recharged to 60% field capacity in the 0- to 50-cm soil profile were adequate for obtaining acceptable yield levels in this intensified double cropping system. Results also showed potential savings of more than 30% of the current N application rates per crop from 300 to 200 kg N ha(-1), which could reduce about 60% of the N leaching without compromising crop yields.

Dynamic functional and mechanical response of breast tissue to compression

Physiological tissue dynamics following breast compression offer new contrast mechanisms for evaluating breast health and disease with near infrared spectroscopy. We monitored the total hemoglobin concentration and hemoglobin oxygen saturation in 28 healthy female volunteers subject to repeated fractional mammographic compression. The compression induces a reduction in blood flow, in turn causing a reduction in hemoglobin oxygen saturation. At the same time, a two phase tissue viscoelastic relaxation results in a reduction and redistribution of pressure within the tissue and correspondingly modulates the tissue total hemoglobin concentration and oxygen saturation. We observed a strong correlation between the relaxing pressure and changes in the total hemoglobin concentration bearing evidence of the involvement of different vascular compartments. Consequently, we have developed a model that enables us to disentangle these effects and obtain robust estimates of the tissue oxygen consumption and blood flow. We obtain estimates of 1.9+/-1.3 micromol/100 mL/min for OC and 2.8+/-1.7 mL/100 mL/min for blood flow, consistent with other published values.

Fast and low power Michelson interferometer thermo-optical switch on SOI

We designed and fabricated silicon-on-insulator based Michelson interferometer (MI) thermo-optical switches with deep etched trenches for heat-isolation. Switch power was reduced approximately 20% for the switch with deep etched trenches, and the MI saved approximately 50% power than that of the Mach-Zehnder interferometer. 10.6 mW switch power, approximately 42 micros switch time for the MI with deep trenches, 13.14 mW switch power and approximately 34 micros switch time for the MI without deep trenches were achieved.

Application of the laguerre deconvolution method for time-resolved fluorescence spectroscopy to the characterization of atherosclerotic plaques

This study investigates the ability of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) to detect inflammation in atherosclerotic lesion, a key feature of plaque vulnerability. A total of 348 TR-LIFS measurements were taken from carotid plaques of 30 patients, and subsequently analyzed using the Laguerre deconvolution technique. The investigated spots were classified as Early, Fibrotic/Calcified or Inflamed lesions. A stepwise linear discriminant analysis algorithm was developed using spectral and TR features (normalized intensity values and Laguerre expansion coefficients at discrete emission wavelengths, respectively). Features from only three emission wavelengths (390, 450 and 500 nm) were used in the classifier. The Inflamed lesions were discriminated with sensitivity > 80% and specificity > 90 %, when the Laguerre expansion coefficients were included in the feature space. These results indicate that TR-LIFS information derived from the Laguerre expansion coefficients at few selected emission wavelengths can discriminate inflammation in atherosclerotic plaques. We believe that TR-LIFS derived Laguerre expansion coefficients can provide a valuable additional dimension for the detection of vulnerable plaques.

Short communication: Identification of allelic variation at the bovine DRA locus by polymerase chain reaction-single strand conformational polymorphism

The major histocompatibility complex DRA locus is noteworthy among the major histocompatibility complex class II loci for the little or no variation reported in many species. In cattle, DRA has not been investigated in depth, and the extent of variation at the locus is not yet known. In this study, we used PCR-single strand conformational polymorphism (SSCP) analysis to screen for potential sequence variation in the second exon of bovine DRA, which encodes the antigen-presentation groove. Four unique SSCP patterns were detected among 384 cattle from New Zealand. Sequence analysis revealed that these SSCP patterns represent 4 DRA alleles; and 3 single nucleotide polymorphisms were detected in exon 2. However, all of the single nucleotide polymorphisms were synonymous, and no amino acid change was therefore expected in this region. The polymorphism detected may be linked to variation elsewhere in the gene that affects its structure or function.

Passive ring-assisted Mach-Zehnder interleaver on silicon-on-insulator

A passive ring-assisted Mach-Zehnder interferometer optical interleaver comprising a Y-bench, a 3-dB directional coupler, a ring-resonator, and a delay line is proposed. The interleaver is fabricated with 300 nm x 300 nm silicon wires on silicon-on-insulator. The fabricated interleaver demonstrates a flat-top spectral response. The measured free-spectral range is approximately 4 nm, the insertion loss is approximately -8 dB, and the crosstalk is <- 10 dB. Both the experimental and simulation results are in good agreement.

Proposed silicon wire interleaver structure

A Ring-resonator Mach-Zehnder interferometer (RR-MZI) optical interleaver structure comprising a ring resonator (RR) and a 3 dB directional coupler is proposed. The interleaver is fabricated with 300 nm x 300 nm silicon wires on silicon-on-insulator (SOI) wafers. The fabricated interleaver demonstrates a flat-top spectral response, and the measured free spectral range (FSR) is approximately 20 nm. The insertion loss (IL) of the device is approximately -10 dB and the polarization dependent loss (PDL) <5 dB. Both the experimental and simulation results are in good agreement.

Low loss (approximately 6.45dB/cm) sub-micron polycrystalline silicon waveguide integrated with efficient SiON waveguide coupler

In this communication, the sub-micron size polycrystalline silicon (poly- Si) single mode waveguides are fabricated and integrated with SiON waveguide coupler by deep UV lithography. The propagation loss of poly-Si waveguide and coupling loss with optical flat polarization-maintaining fiber (PMF) are measured. For whole C-band (i.e., lambda approximately 1520-1565nm), the propagation loss of TE mode is measured to approximately 6.45+/-0.3dB/cm. The coupling loss with optical flat PMF is approximately 3.4dB/facet for TE mode. To the best of our knowledge, the propagation loss is among the best reported results. This communication discusses the factors reducing the propagation loss, especially the effect of the refractive index contrast. Compared to the SiO(2) cladding, poly-Si waveguide with SiON cladding exhibits lower propagation loss.

Effect of RBP4 gene variants on circulating RBP4 concentration and type 2 diabetes in a Chinese population

AIMS

Retinol binding protein 4 (RBP4) is a newly discovered adipokine, which plays a role in insulin resistance and obesity. The aim of this study was to determine the relationship between genetic variants of the RBP4 gene, circulating RBP4 concentrations and phenotypes related to glucose and lipid metabolism in the Chinese population.

METHODS

We sequenced exons and the putative promoter region to identify single nucleotide polymorphisms (SNPs) in the RBP4 gene in 32 Chinese subjects. Additional SNPs were selected from a public database to increase marker density. Taking account of the pairwise linkage disequilibrium and minor allele frequencies, a subset of SNPs was further genotyped in 255 Type 2 diabetic patients and 372 normal control subjects. Circulating RBP4 concentrations and phenotypes related to glucose and lipid metabolism were measured.

RESULTS

Ten SNPs were identified and five were further genotyped in the full sample. No individual SNP was significantly associated with Type 2 diabetes, but a rare haplotype CAA formed by +5388 C>T, +8201 T>A and +8204 T>A was more frequent in diabetic patients (P = 0.0343, empirical P = 0.0659 on 10 000 permutations). In both groups, non-coding SNPs were associated with circulating RBP4 concentrations (P < 0.05). In the normal control subjects, the SNP +5388 C>T was associated with serum C-peptide levels both fasting and 2 h after an oral glucose tolerance test (P = 0.0162 and P = 0.0075, respectively).

CONCLUSION

Our findings suggest that genetic variants in the RBP4 gene may be associated with circulating RBP4 concentration and phenotypes related to glucose metabolism.

Freezing points and small-scale deicing tests for salts of levulinic acid made from grain sorghum

Deicers from renewable resources are needed to overcome the disadvantages of using traditional deicers. Salts made from levulinic acid produced using grain sorghum as raw material were tested as road deicing agents. Freezing points of these salts viz., sodium levulinate, magnesium levulinate and calcium levulinate along with rock salt (sodium chloride) were determined according to American Society for Testing and Materials (ASTM) D 1177-94 standard at concentrations of 10, 20, 30 and 40 % w/w. There were significant differences among the freezing points of the salts. Freezing points for rock salt, sodium levulinate, calcium levulinate and magnesium levulinate, for different concentrations, were in the ranges of -6.6 to -20.5, -2.9 to -15.0, -2.1 to -7.8 and -1.5 to -6.5 degrees C, respectively. Deicing effectiveness of the salts of levulinic acid were investigated by conducting small-scale deicing tests with aqueous solutions of various salt concentrations (2%, 5% and 10%) in a laboratory freezer and by spraying the deicer on a graveled surface covered by ice and snow with the average temperature during the testing at -2.7 degrees C. Deicing capabilities of the three salts of levulinic acid differed. At -2.7 degrees C, all three salts caused melting of the ice. Among the different levulinates studied sodium levulinate was the most effective deicing agent. These salts of levulinates could be a viable replacement for traditional deicers and could help in reducing the disadvantages of traditional deicers.

Study of ATP-binding cassette transporter A1 (ABCA1)-mediated cellular cholesterol efflux in diabetic golden hamsters

The effects of cyclic adenosine monophosphate (cAMP) and atorvastatin on macrophage adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux were investigated in a diabetic animal model. Golden hamsters were fed a high-fat diet which resulted in insulin resistance. Diabetes was induced by a single intraperitoneal injection of streptozotocin (30 mg/kg). Normal golden hamsters were used as controls. Peritoneal macrophages were incubated with apolipoprotein A-1 (apoA-1), 8-bromoadenosine-3',5'-cyclic monophosphate (8-br-cAMP), and atorvastatin in vitro. Intracellular cholesterol accumulation was greater in the diabetic animals than in the insulin-resistant animals. Expression of ABCA1 mRNA in macrophages from diabetic animals was upregulated by 8-br-cAMP and atorvastatin. ApoA-1 caused a time-dependent cellular cholesterol efflux. Both atorvastatin and 8-br-cAMP significantly facilitated ABCA1-mediated cellular cholesterol efflux, with the maximal cholesterol efflux rate observed in the macrophages from diabetic animals. Accumulation of cholesterol in the macrophages of diabetic animals can be significantly alleviated by atorvastatin or 8-br-cAMP through improving ABCA1-mediated cellular cholesterol efflux.

Polymorphism of the DQA2 gene in goats

Variation in the caprine DQA2 gene was investigated using PCR-single-strand conformational polymorphism (SSCP) and DNA sequencing. Eleven DQA2 alleles were defined by SSCP patterns from 23 goats. All the caprine alleles shared high sequence homology to ovine DQA2 sequences, and exhibited a pattern of polymorphism similar to DQA2 alleles from sheep and cattle but different from caprine DQA1 sequences. Thirty-eight AA positions in the alpha1 domain of caprine DQA2 molecules were polymorphic, and a high degree of polymorphism was observed in the putative antigen-binding region, with 74% of the positions being polymorphic. Phylogenetic analysis of caprine, ovine, and bovine DQA sequences revealed that the caprine DQA2 sequences identified here grouped with ovine DQA2, bovine DQA2, DQA3, and DQA4 sequences but are separate from the group of caprine DQA1 alleles. Nine of the caprine DQA2 sequences were more similar to ovine DQA2 alleles, whereas the remaining two were more closely related to ovine DQA2-like and bovine DQA3 alleles. This finding suggests that the caprine DQA2 sequences may represent two loci, which probably arose by either gene duplication or gene conversion events. Allelic lineages were evident for both DQA2 and DQA2-like loci, supporting the trans-species mode of evolution of major histocompatibilitly complex genes. The high level of polymorphism and similarity between caprine and ovine DQA2 alleles suggests that the DQA2 gene may play an important role in immune responses to shared pathogens.

Technical note: determination of alleles of the ovine PRNP gene using PCR-single-strand conformational polymorphism analysis

Susceptibility to scrapie in sheep is linked to variation at codons 136, 154, and 171 in the host prion protein gene (PRNP). A number of techniques are available for detecting these polymorphisms, but none allow for a rapid and accurate determination of genotype. Here we describe PCR coupled with single-strand conformational polymorphism (SSCP) analysis, which allows for the accurate identification of ovine PRNP alleles. A gene region including codons 136 to 171 was amplified by PCR, and the amplimers were then denatured and subjected to electrophoresis in a nondenaturing polyacrylamide gel. Nine unique SSCP patterns, representing nine different alleles of the ovine PRNP gene, could be resolved. A new polymorphism (I/T) at codon 142 also was detected. The profiles produced by SSCP allowed for the accurate differentiation of PRNP alleles and could be employed to genotype PRNP in sheep.

Novel methods of time-resolved fluorescence data analysis for in-vivo tissue characterization: application to atherosclerosis

This study investigates the ability of new analytical methods of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) data to characterize tissue in-vivo, such as the composition of atherosclerotic vulnerable plaques. A total of 73 TR-LIFS measurements were taken in-vivo from the aorta of 8 rabbits, and subsequently analyzed using the Laguerre deconvolution technique. The investigated spots were classified as normal aorta, thin or thick lesions, and lesions rich in either collagen or macrophages/foam-cells. Different linear and nonlinear classification algorithms (linear discriminant analysis, stepwise linear discriminant analysis, principal component analysis, and feedforward neural networks) were developed using spectral and TR features (ratios of intensity values and Laguerre expansion coefficients, respectively). Normal intima and thin lesions were discriminated from thick lesions (sensitivity >90%, specificity 100%) using only spectral features. However, both spectral and time-resolved features were necessary to discriminate thick lesions rich in collagen from thick lesions rich in foam cells (sensitivity >85%, specificity >93%), and thin lesions rich in foam cells from normal aorta and thin lesions rich in collagen (sensitivity >85%, specificity >94%). Based on these findings, we believe that TR-LIFS information derived from the Laguerre expansion coefficients can provide a valuable additional dimension for in-vivo tissue characterization.

Novel ultra-fast deconvolution method for fluorescence lifetime imaging microscopy based on the Laguerre expansion technique

A new deconvolution method for fluorescence lifetime imaging microscopy (FLIM) based on the Laguerre expansion technique is presented. The performance of this method was tested on synthetic FLIM images derived from a multiexponential model and from fluorescence lifetime standards, and then compared to standard algorithms of FLIM analysis. Our results demonstrated significant advantages of the Laguerre method over standard algorithms. First, the fluorescence intensity decays of arbitrary form can be estimated at every pixel, without a priori assumption of its functional form. Second, the number of delayed images required to perform deconvolution is relatively low (as low as 5), reducing the acquisition time. Third, ultra-fast light sources are not longer required, making less expensive to perform lifetime imaging. Finally and most important, deconvolution at every pixel is performed in parallel using a common Laguerre basis, thus allowing reducing significantly the computation time (i.e. synthetic 600x600 pixel images can be deconvolved with high accuracy in less than 20 s). Based on these findings, we believe that the Laguerre deconvolution technique represents a more robust and extremely fast analytical method that will allow exploring FLIM in practical real-time applications, such as clinical diagnosis.

Haplotype analysis of the DQA genes in sheep: Evidence supporting recombination between the loci1

The ovine class II major histocompatibility complex mediates specific immune responses to exogenous antigens in sheep. A number of ovine class II loci have been identified, and most of them appear to be polymorphic. In this study we investigated the DQA1 locus of 520 sheep and the DQA2 locus of over 40,000 sheep, finding 12 sequences and 22 sequences, respectively, using DQA1- and DQA2-specific PCR primers. Among the DQA2 sequences, 2 groups of sequences can be found: those that share homology with the DQA2 sequences from closely related species and those that cluster with bovine DQA3 and DQA4 sequences and have been called DQA2-like in sheep. The occurrence of these DQA2-like sequences was once again confirmed to correspond with the absence of detectable DQA1 sequences, suggesting that they are found at the same location as DQA1. Within the sheep studied, 37 haplotypes could be detected, 23 being haplotypes of DQA1 and DQA2 sequences and with frequencies ranging from 0.38 to 9.27%, and 14 being haplotypes of DQA2 and DQA2-like sequences and with frequencies ranging from 0.03 to 14.53%. We discovered 12 DQA1-DQA2 combinations that were derived from 5 DQA1 alleles and 4 DQA2 alleles, and 8 DQA2-DQA2-like combinations from 5 DQA2 alleles and 2 DQA2-like sequences. The frequency of occurrence of recombined DQA1-DQA2 sequences and recombined DQA2-DQA2-like sequences is similar, once again suggesting the DQA2-like sequences are found at the DQA1 locus.

Comparison of fibroglandular tissue distributions for microwave tomographic breast images with complementary MR T2 weighted images

We have recently demonstrated good correlation between the recovered permittivity from microwave imaging (MIS) and the recovered water content from near infrared imaging (NIR) for a common set of normal patients undergoing associated breast examinations. We have subsequently conducted a small sample of comparison breast examinations between microwave imaging and MR to assess possible correlation between the location and extent of the fibroglandular as seen on MR images with increased permittivity zones of the microwave images. From various physiological and MR breast studies, it has been shown that the fibroglandular regions are generally comprised of significantly higher levels of water than the more dominant adipose tissue. The initial results of this study are quite encouraging and demonstrate obvious correlations between the permittivity and MR-recovered fibroglandular regions for a set of patients with widely varying tissue type variations. In addition, they illustrate the value of extracting diagnostic information from multiple modalities especially where the amount of direct in vivo property measurements is limited or nonexistent.

Electrically tunable Bragg gratings in single-mode polymer optical fiber

We present what is to our knowledge the first demonstration of a tunable fiber Bragg grating device in polymer optical fiber that utilizes a thin-film resistive heater deposited on the surface of the fiber. The polymer fiber was coated via photochemical deposition of a Pd/Cu metallic layer with a procedure induced by vacuum-ultraviolet radiation at room temperature. The resulting device, when wavelength tuned via joule heating, underwent a wavelength shift of 2 nm for a moderate input power of 160 mW, a wavelength to input power coefficient of -13.4 pm/mW, and a time constant of 1.7 s(-1).

New Methods for Time-resolved Fluorescence Spectroscopy Data Analysis Based on the Laguerre Expansion Technique

Objectives : A new deconvolution method for the analysis of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) data is introduced and applied for tissue diagnosis.

Method : The intrinsic TR-LIFS decays are expanded on a Laguerre basis, and the computed Laguerre expansion coefficients (LEC) are used to characterize the sample fluorescence emission. The method was applied for the diagnosis of atherosclerotic vulnerable plaques.

Results : At a first stage, using a rabbit atherosclerotic model, 73 TR-LIFS in-vivo measurements from the normal and atherosclerotic aorta segments of eight rabbits were taken. The Laguerre deconvolution technique was able to accurately deconvolve the TR-LIFS measurements. More interesting, the LEC reflected the changes in the arterial biochemical composition and provided discrimination of lesions rich in macrophages/foamcells with high sensitivity (> 85%) and specificity (> 95%). At a second stage, 348 TR-LIFS measurements were obtained from the explanted carotid arteries of 30 patients. Lesions with significant inflammatory cells (macrophages/foam-cells and lymphocytes) were detected with high sensitivity (> 80%) and specificity (> 90%), using LEC-based classifiers.

Conclusion : This study has demonstrated the potential of using TR-LIFS information by means of LEC for in- vivo tissue diagnosis, and specifically for detecting inflammation in atherosclerotic lesions, a key marker of plaque vulnerability.

New methods for time-resolved fluorescence spectroscopy data analysis based on the Laguerre expansion technique--applications in tissue diagnosis

OBJECTIVES

A new deconvolution method for the analysis of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) data is introduced and applied for tissue diagnosis.

METHOD

The intrinsic TR-LIFS decays are expanded on a Laguerre basis, and the computed Laguerre expansion coefficients (LEC) are used to characterize the sample fluorescence emission. The method was applied for the diagnosis of atherosclerotic vulnerable plaques.

RESULTS

At a first stage, using a rabbit atherosclerotic model, 73 TR-LIFS in-vivo measurements from the normal and atherosclerotic aorta segments of eight rabbits were taken. The Laguerre deconvolution technique was able to accurately deconvolve the TR-LIFS measurements. More interesting, the LEC reflected the changes in the arterial biochemical composition and provided discrimination of lesions rich in macrophages/foam-cells with high sensitivity (> 85%) and specificity (> 95%). At a second stage, 348 TR-LIFS measurements were obtained from the explanted carotid arteries of 30 patients. Lesions with significant inflammatory cells (macrophages/foam-cells and lymphocytes) were detected with high sensitivity (> 80%) and specificity (> 90%), using LEC-based classifiers.

CONCLUSION

This study has demonstrated the potential of using TR-LIFS information by means of LEC for in vivo tissue diagnosis, and specifically for detecting inflammation in atherosclerotic lesions, a key marker of plaque vulnerability.

Peroxisome proliferator-activated receptor (PPAR) delta genetic polymorphism and its association with insulin resistance index and fasting plasma glucose concentrations in Chinese subjects

AIMS

Previous studies have shown that the peroxisome proliferator-activated receptor delta (PPARD) genetic polymorphism affects cholesterol metabolism in Whites. This association was not observed in a Korean population in a separate study, but this study showed a link between the PPARD polymorphism and body weight and fasting plasma glucose. The purpose of this study was to determine whether polymorphisms of PPARD influence glucose and cholesterol metabolism in Chinese subjects. We investigated the association between the polymorphism (-87T/C) of the human PPARD gene and phenotypes related to body weight, insulin sensitivity, glucose and lipid metabolism in Chinese subjects.

METHODS

Unrelated Chinese subjects (n = 663) in Shanghai were studied; 287 had newly diagnosed Type 2 diabetes mellitus and 376 were non-diabetic control subjects over 40 years old. Clinical parameters were collected and genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

In normal glucose tolerant (NGT) subjects, the C allele carriers had higher fasting plasma glucose concentrations (P = 0.0078) and a lower insulin sensitivity index (ISI) (P = 0.0365). The C allele carriers also showed higher concentrations of low-density lipoprotein cholesterol (P = 0.0261) and percentage of body fat (P = 0.0357). There was a trend towards higher visceral adiposity in C allele carriers, but the difference was not significant (P = 0.0830). In diabetes patients, similar results were detected for plasma glucose concentrations (fasting plasma glucose P < 0.0001, 2-h plasma glucose P = 0.0052) and insulin sensitivity (homeostasis model assessment of insulin resistance P = 0.0094; ISI P = 0.0058).

CONCLUSION

The PPARD-87T/C polymorphism is associated with higher fasting plasma glucose concentrations in both NGT and diabetic subjects, largely due to impaired insulin sensitivity.

Diagnosis of vulnerable atherosclerotic plaques by time-resolved fluorescence spectroscopy and ultrasound imaging

In this study, time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) and ultrasonography were applied to detect vulnerable (high-risk) atherosclerotic plaque. A total of 813 TR-LIFS measurements were taken from carotid plaques of 65 patients, and subsequently analyzed using the Laguerre deconvolution technique. The investigated spots were classified by histopathology as thin, fibrotic, calcified, low-inflamed, inflamed and necrotic lesions. Spectral and time-resolved parameters (normalized intensity values and Laguerre expansion coefficients) were extracted from the TR-LIFS data. Feature selection for classification was performed by either analysis of variance (ANOVA) or principal component analysis (PCA). A stepwise linear discriminant analysis algorithm was developed for detecting inflamed and necrotic lesion, representing the most vulnerable plaques. These vulnerable plaques were detected with high sensitivity (>80%) and specificity (>90%). Ultrasound (US) imaging was obtained in 4 carotid plaques in addition to TR-LIFS examination. Preliminary results indicate that US provides important structural information of the plaques that could be combined with the compositional information obtained by TR-LIFS, to obtain a more accurate diagnosis of vulnerable atherosclerotic plaque.

Structural, interfacial and optical characterization of ultrathin zirconia film grown byin situthermal oxidation of sputtered metallic Zr films

High dielectric constant ZrO₂gate dielectric thin films have been prepared by means ofin situthermal oxidation of sputtered metallic Zr films. XRD reveals that the as-oxidized samples are amorphous, but can be made polycrystalline with a highly ()-preferential orientation by increasing the annealing temperature. AFM measurements confirm that high temperature annealing results in increase of the roughness root mean square value of the films. The growth and properties of the interfacial SiO₂layer formed at the ZrO₂/Si interface are observed by using Fourier transform infrared spectroscopy. It has been found that the formation of the interfacial layer depends on the post-deposition annealing temperature. On the basis of a parametrized Tauc-Lorentz dispersion model, the optical properties of the as-oxidized and annealed films related to the annealing temperature are systematically investigated by spectroscopic ellipsometry. The increase in the refractive index and decrease in extinction coefficient with increase of the annealing temperature are discussed in detail.

Molecular characterization of a major outer capsid protein encoded by the Threadfin aquareovirus (TFV) gene segment 10 (S10)

Genome segment 10 (S10) of Threadfin aquareovirus (TFV) was cloned, sequenced, analyzed and found to be 987 bp long encoding a protein of 298 aa with a predicted molecular mass of 32.0 kDa. The TFV S10 gene possesses terminal motifs, (5' GTTTTA and ATTCATC 3') which are also conserved in the S6 and S11 TFV gene segments. Sequence comparison revealed that the TFV S10 gene was similar to the Striped bass reovirus (SBR) VP7 outer capsid protein (OCP). A conserved putative zinc-finger motif, CCHC, present in the mammalian reovirus (MRV) delta3 protein, was identified in TFV and other aquareovirus VP7 protein. Phylogenetic analysis of the TFV VP7 protein indicated that TFV is closely related to SBR and Chum salmon reovirus (CSV) and possibly belong to the same species Aquareovirus A as SBR and CSV. The TFV VP7 protein was expressed in E. coli, purified and injected into mice. Serum specific antibodies were generated, however, the serum showed weak neutralizing activity. In contrast, co-incubation of this serum with another serum obtained from mice immunized with another OCP encoded by the TFV S6 gene segment resulted in a highly elevated antibody neutralization titer.

Thrombin induces collagen gel contraction partially through PAR1 activation and PKC-epsilon

The ability of fibroblasts to contract three-dimensional collagen gels has been used as an in vitro model of the tissue contraction which characterises both normal repair and fibrosis. Among its actions, thrombin can activate the protease-activated receptor (PAR)1 and, thereby, stimulate inflammation and repair. The current study evaluated whether thrombin could stimulate fibroblast-mediated collagen gel contraction by activating PAR1 and whether its downstream signalling depends on protein kinase C (PKC)-epsilon. Human foetal lung fibroblasts (HFL-1) were cultured in three-dimensional collagen gels and the area of the gels was measured by image analyser. Both thrombin and TFLLR, a selective PAR1 agonist, stimulated collagen gel contraction mediated by HFL-1. After RNA interference-mediated PAR1 knockdown in HFL-1, both thrombin and the PAR1 agonist-induced gel contraction were partially inhibited (by 22.4+/-2.2% and 17.6+/-5.6%, respectively). The gel contraction stimulated by thrombin was also reduced by a nonspecific PKC inhibitor and a calcium-independent PKC-epsilon inhibitor. Both thrombin and TFLLR significantly increased PKC-epsilon activity, and this effect was blocked by PAR1 knockdown. Thrombin stimulates collagen gel contraction at least partially through activation of protease-activated receptor 1 and protein kinase C-epsilon, and may contribute to tissue remodelling in inflammatory airway and lung diseases.

Studies on the chemopreventive potentials of vegetable oils and unsaturated fatty acids against breast cancer carcinogenesis at initiation

The effect of dietary fat on breast cancer is a longstanding and an unresolved issue. We found that 17beta-estradiol (E2) could be activated by the epoxide-forming oxidant dimethyldioxirane (DMDO) to bind DNA-forming DNA adducts both in vitro and in vivo, and to inhibit nuclear RNA synthesis. We proposed that E2 epoxidation is the underlying mechanism for the initiation of breast cancer carcinogenesis (Carcinogenesis 17, 1957-61, 1996). This report is on the transcriptional and DNA-binding properties of vegetable oils and fatty acids, and on the potentials of these compounds to prevent the formation of E2 epoxide. The results show that vegetable oils, having no effect on nuclear RNA synthesis either before or after DMDO treatment, were all able to prevent the formation of E2 epoxide independent of their mono- or polyunsaturated fatty acid content. Similarly, unsaturated fatty acids, regardless of chain length and number of double bonds, were all able to prevent the formation of E2 epoxide as reflected by the loss of the ability of [3H]E2 to bind DNA. In contrast to vegetable oils, the results indicated that the unsaturated fatty acids palmitoleic, oleic, linoleic, linolenic and arachidonic acid could be activated by DMDO to inhibit nuclear RNA synthesis, and that the mono-unsaturated fatty acids (i.e. palmitoleic and oleic acid) were stronger inhibitors than fatty acids with more than one double bond (e.g. linoleic, linolenic and arachidonic acid). [32P]Post-labeling analysis revealed that under identical DMDO activation, the DNA adducts formed for oleic acid were 17098 adducts/10(8) nucleotides, which was 20-fold more than palmitoleic acid (815), and 120-fold more than alpha-linolenic acid (142). This result strongly suggests that oleic acid could be a potential initiating carcinogen after epoxidation.