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.

Scanning for MODY5 gene mutations in Chinese early onset or multiple affected diabetes pedigrees

Mutation of HNF-1beta gene has been reported in early onset diabetes or MODY families and this gene has been defined as MODY5 gene. The aim of our study was to examine whether HNF-1beta mutation contribute to early onset or multiple affected diabetes pedigrees in Chinese. Molecular scanning of HNF-1beta gene promoter region, nine exons and flanking introns was performed in 154 unrelated probands from early onset and multiple affected diabetes Chinese pedigrees. The family members of probands with mutations or variants and 58 nondiabetics were also examined. Clinical examinations of renal morphology, renal function and beta-cell function were performed in the HNF-1beta gene mutation carriers and family members. Mutation of HNF-1beta gene causing the substitution S36F was found in two subjects of an early onset diabetic family. One carrier has early onset diabetes, renal function impairment and renal cyst, while the other has impaired glucose tolerance only. This is the first case of MODY5 gene mutation diabetes found in the Chinese. Three HNF-1beta variants were identified and no significant differences in allele frequencies for these variants were detected between the nondiabetic and diabetic groups. Nucleotide 66 of intron 8 of HNF-1beta gene was G in the Chinese population rather than A as noted in the GenBank sequence. These results suggest that HNF-1beta gene mutations may be associated with nondiabetic renal dysfunction and diabetes in Chinese, but they are responsible for only a small percentage of early onset or multiple affected diabetes pedigrees including MODY.

Microwave thermal imaging: initial in vivo experience with a single heating zone

The deployment of hyperthermia as a routine adjuvant to radiation or chemotherapy is limited largely by the inability to devise treatment plans which can be monitored through temperature distribution feedback during therapy. A non-invasive microwave tomographic thermal imaging system is currently being developed which has previously exhibited excellent correlation between the recovered electrical conductivity of a heated zone and its actual temperature change during phantom studies. To extend the validation of this approach in vivo, the imaging system has been re-configured for small animal experiments to operate within the bore of a CT scanner for anatomical and thermometry registration. A series of 5-7 day old pigs have been imaged during hyperthermia with a monopole antenna array submerged in a saline tank where a small plastic tube surgically inserted the length of the abdomen has been used to create a zone of heated saline at pre-selected temperatures. Tomographic microwave data over the frequency range of 300-1000 MHz of the pig abdomen in the plane perpendicular to the torso is collected at regular intervals after the tube saline temperatures have settled to the desired settings. Images are reconstructed over a range of operating frequencies. The tube location is clearly visible and the recovered saline conductivity varies linearly with the controlled temperature values. Difference images utilizing the baseline state prior to heating reinforces the linear relationship between temperature and imaged saline conductivity. Demonstration of in vivo temperature recovery and correlation with an independent monitoring device is an important milestone prior to clinical integration of this non-invasive imaging system with a thermal therapy device.

Development of a rapid, sensitive and specific diagnostic assay for fish Aquareovirus based on RT-PCR

A rapid, sensitive and highly specific detection method for Aquareovirus based on reverse-transcription polymerase chain reaction (RT-PCR) was developed. Based on multiple sequence alignment of the cloned sequences of a local isolates, the Threadfin reovirus (TFV) and Guppy reovirus (GPV) with Grass carp reovirus (GCRV), a pair of degenerate primers was selected carefully and synthesized. Using this primer combination, only one specific product, approximately 450 bp in length was obtained when RT-PCR was carried out using the genomic double-stranded RNA (dsRNA) of TFV, GPV and GCRV. Similar results were also obtained when Chum salmon reovirus (CSRV) and Striped bass reovirus (SBRV) dsRNA were used as templates. No products were observed when nucleic acids other than the dsRNA of the aquareoviruses described above were used as RT-PCR templates. This technique could detect not only TFV but also GPV and GCRV in low titer virus-infected cell cultured cells. Furthermore, this method has also been shown to be able to diagnose GPV-infected guppy (Poecilia reticulata) that exhibit clinical symptoms as well as GPV-carrier guppy. Collectively, these results showed that the RT-PCR amplification method using specific degenerate primers described below is very useful for rapid and accurate detection of a variety of aquareovirus strains isolated from different host species and origin.

Diversity of the ovine DQA2 gene1

Variation in the ovine DQA2 gene was investigated in approximately 2,000 sheep from six breeds. Fragments of DNA containing the ovine DQA2 exon 2 were amplified using PCR. Single-strand conformational polymorphism analysis and DNA sequence analysis were employed to detect genetic variation. Twenty-three nucleic acid sequences, encoding 22 DQA2 amino acid sequences, were identified. This increases the number of alleles identified from 10 to 23. In some cases, three or four unique sequences were isolated from individual sheep, suggesting that these DQA2 sequences may represent two loci. Phylogenetic tree analysis revealed that 5 of these 23 sequences were more closely related to cattle DQA3 or DQA4 sequences than to other sheep DQA2 sequences. These sequences clustered together and were called DQA2-like to differentiate them from other DQA2 sequences. There was no evidence of DQA5-like sequences in sheep. Information theory-based analysis indicated that some of the DQA2-like sequences had low information content at splice sites, suggesting that these alleles may have low functional activity. Allelic lineages were observed not only at the DQA2 locus, but also at the DQA2-like locus, supporting the trans-species mode of evolution of MHC genes. Comparison of the allelic sequences suggests that polymorphism seems to have arisen largely by point mutation and gene conversion, and a recent gene conversion event seems to have occurred between the DQA2 and DQA2-like loci. The high level of sequence polymorphism detected and varied number of loci demonstrate the extensive diversity of the ovine DQA2 gene.

Crystal structure of 2,3-bis(2-cyanoethylthio)-6,7-vinylenedithiotetrathiafulvalene, C14H10N2S8

C14H10N2S8, triclinic, P1̅ (no. 2), a = 7.753(2) Å, b = 11.403(3) Å, c = 12.371(5) Å, α = 64.10(2)°, β = 84.62(2)°, γ = 77.34(2)°, V = 959.9 Å3, Z = 2, Rgt(F) = 0.061, wRref(F2) = 0.168, T = 293 K.

Crystal structure of 4,5-(ethoxyethylenedithio)-1,3-dithiole-2-thione, C7H8OS5

C7H8OS5, monoclinic, P121/c1 (No. 14), a = 8.3699(7) Å, b = 17.573(2) Å, c = 7.5305(7) Å, β = 103.584(7)°, V = 1076.6 Å3, Z=4, Rgt(F) = 0.033, wRref(F2) = 0.082, T = 293 K.

Nonparametric Analysis Of Time-Resolved Fluorescence Data Based On The Laguerre Expansion Technique

To estimate the intrinsic fluorescence intensity decay of a compound, the excitation light pulse must be deconvolved from the measured fluorescence pulse trace. The most commonly used deconvolution method is the multiexponential least-square iterative reconvolution (LSIR) technique. A variant of LSIR in which the intrinsic fluorescence intensity decay is expressed as an expansion on the discrete time Laguerre basis, was recently introduced. In this study, the performance of the Laguerre deconvolution technique was successfully tested with simulated and fluorescence standard data. It was also demonstrated that the Laguerre deconvolution presents a number of advantages over the classical multiexponential LSIR, including less expensive computational resolution, and the property to generate a unique set of expansion coefficients highly correlated with the intrinsic lifetimes. A novel method for concentration estimation based on the analysis of the Laguerre expansion coefficients was also proposed and successfully applied to different fluorescence standard mixtures, performing even better (error<2%) than more traditional methods of spectral analysis, such as PCR (error<7%) and PLS (error<10%). These findings suggest that the use of Laguerre expansion coefficients represents an alternative nonparametric approach to characterize and discriminate biological systems, in terms of their spectral and lifetime characteristics.

Crystal structure of tetra-n-butylammonium (1,3-dithiol-2-thione-4,5-dithiolato)-( diethyldithiocarbamato-S,S')-nickelate(II), (C16H36N)(C8H10NNiS7)

C24H46N2NiS7, monoclinic, C1c1 (No. 9), a = 8.846(2) Å, b = 24.702(6) Å, c = 15.392(3) Å, β = 95.12(1)°, V = 3349.9Å3, Z = 4, Rgt(F) = 0.059, wRref(F2) = 0.166, T = 293 K.

Image accuracy improvements in microwave tomographic thermometry: phantom experience

Evaluation of a laboratory-scale microwave imaging system for non-invasive temperature monitoring has previously been reported with good results in terms of both spatial and temperature resolution. However, a new formulation of the reconstruction algorithm in terms of the log-magnitude and phase of the electric fields has dramatically improved the ability of the system to track the temperature-dependent electrical conductivity distribution. This algorithmic enhancement was originally implemented as a way of improving overall imaging capability in cases of large, high contrast permittivity scatterers, but has also proved to be sensitive to subtle conductivity changes as required in thermal imaging. Additional refinements in the regularization procedure have strengthened the reliability and robustness of image convergence. Imaging experiments were performed for a single heated target consisting of a 5.1 cm diameter PVC tube located within 15 and 25 cm diameter monopole antenna arrays, respectively. The performance of both log-magnitude/phase and complex-valued reconstructions when subjected to four different regularization schemes has been compared based on this experimental data. The results demonstrate a significant accuracy improvement (to 0.2 degrees C as compared with 1.6 degrees C for the previously published approach) in tracking thermal changes in phantoms where electrical properties vary linearly with temperature over a range relevant to hyperthermia cancer therapy.

Aberrant monocyte prostaglandin synthase 2 (PGS2) expression in type 1 diabetes before and after disease onset

METHODS

We examined monocyte prostaglandin synthase 2 (PGS2/COX2) expression in individuals at risk for or with type 1 diabetes including: (i) 58 established type 1 and 2 diabetic patients; (ii) 34 autoantibody positive (AA+) children and adults; (iii) 164 infants and young children with insulin-dependent diabetes mellitus (IDDM) susceptibility human leukocyte antigen (HLA) alleles; and (iv) 37 healthy control individuals, over a 5-yr period.

RESULTS

Established type 1 diabetic patients (1 month to 30+ yr post-disease onset) had significantly higher PGS2 expression than healthy controls; by contrast, insulin-treated type 2 diabetic patients had significantly lower PGS2 expression than healthy controls. Longitudinal studies of AA+ subjects at risk for type 1 diabetes indicated that 73% (11/15) of individuals who developed this disease during the study period expressed high levels of PGS2 prior to or after onset. We also found high level PGS2 expression in genetically at-risk infants and young children that correlated with having a first-degree relative with type 1 diabetes, but not with age, gender, or HLA genotype. In this population, high level PGS2 expression coincided with or preceded autoantibody detection in 30% (3/10) of subjects.

CONCLUSIONS

These findings suggest that high level monocyte PGS2 expression, although subject to fluctuation, is present in at-risk subjects at an early age and is maintained during progression to and after type 1 diabetes onset.

In vivo study of intradermal focusing for tattoo removal

Delivery of intradermally focused nanosecond laser pulses with small energy as an alternate technique applicable to clinical procedures in dermatological and plastic surgery is an area of relatively new interest with multiple potential applications. We assessed this approach on common tattoo pigments in dermis in an in vivo study using a wavelength of 1064 nm. Paired micropigs were tattooed with standard blue, black, green and red pigments. The tattoos were allowed to mature and then treated by 12 ns pulses in a focused beam of 11.4 degrees cone angle. Visual observation and histological analysis of biopsies were performed to evaluate results. Significant reduction in pulse energy and collateral damage was achieved with pulse energy ranging between 38 to 63 mJ. Blue and black tattoos were found to respond well from a clinical standpoint. The depth dependence of tissue response and pigment redistributions at 1 hour, 1 week and 1 month after laser treatment was quantitatively analysed through biopsies and a strong relationship was demonstrated between tattoo response and laser-induced dermal vacuolation. The optical absorption coefficients of the four tattoo pigments were measured to be approximately the same and the laser-induced plasma is suggested to be responsible for the pigment redistribution. As we hypothesised, intradermal focusing of nanosecond pulses significantly reduced required pulse energy for tattoo ablation to about 60 mJ or less. These results stimulate a number of additional questions relevant not only to clinical applications but also to the understanding of the fundamental process of laser-pigment interaction in the dermis as it relates to tattoo removal.

[The impact of calpain-10 gene combined-SNP variation on type 2 diabetes mellitus and its related metabolic traits]

OBJECTIVE

To investigate the impact of calpain-10 gene (CAPN-10) combined single nucleotide polymorphism (SNP) variation on type 2 diabetes mellitus (T2DM) and its related clinical metabolic traits in Chinese.

METHODS

The study population consisted of 268 Chinese residents in Shanghai. Among them, 144 were subjects with normal glucose tolerance (NGT) and 124, with T2DM. Plasma glucose (PG), insulin (INS), c-peptide (CP) and free fatty acids (FFA) levels were measured at fasting and 30, 60, 120, and 180 minutes after oral 75 g glucose challenge. The islet beta-cell insulin secretion and tissue insulin sensitivity were assessed. CAPN-10 UCSNP44,-43,-19 and -63 were genotyped.

RESULTS

(1) In Chinese NGT subjects, the major allele of UCSNP-44 was allele T (frequency=91%), of UCSNP43 was G(89%), of UCSNP-19 was I (3 repeats of a 32 bp sequence) (67%) and of UCSNP-63 was C allele (79%). Significant differences were observed in comparison of these allele frequencies in Chinese to those in other ethnic groups reported in the literature. (2) 14 genotype combinations of these four SNPs were observed in Chinese NGT subjects. 69% of the NGT population was composed of four genotype combinations, in the order of UCSNP44,-43,-19 and -63, i.e., combination A:TT-GG-DI-CC(haplotype combination was 1121/1111) (frequency=10%), combination B:TT-GA-II-CC(1121/1221)(10%), combination C:TT-GG-II-CC(1121/1121)(26%) and combination D:TT-GG-DI-CT(1121/1112)(22%).(3) The frequencies of the above mentioned SNP in single or in combinations were not different significantly between NGT and T2DM groups. (4) The variation of clinical metabolic parameter levels shifted from completely normal towards abnormal glucose intolerance among genotype combination subgroups. In comparison between combination A and combination D, subjects in the former subgroups had: higher PG levels with delayed peak after glucose challenge; less and lower decrement of FFA levels after challenge with no rising in late stage; higher insulin levels with delayed peak after challenge; and the tendency of decreased insulin sensitivity. More than half of the comparisons remained statistically significant after adjusted with age, gender, body mass index and waist circumference.

CONCLUSION

The variation of calpain-10 gene has impact on the variation of clinical metabolic parameter levels related to type 2 diabetes mellitus. Such impact depends upon the haplotypes as well as the haplotype combination of calpain-10 gene variations.

Genetic modification of hematopoietic progenitor cells for combined resistance to 4-hydroperoxycyclophosphamide, vincristine, and daunorubicin

AIM

To investigate whether human peripheral blood hematopoietic progenitor cells (PBPC) modified with human aldehyde dehydrogenase class-3 gene (ALDH-3) and multidrug resistance gene 1 (MDR1) would increase chemotherapy resistance to 4-hydroperoxycyclophosphamide (4-HC) and -glycoprotein effluxed drugs.

METHODS

A bicistronic retroviral vector G1Na-ALDH3-IRES-MDR1 cDNA was constructed and used to transfect the packaging cell lines PA317 by electroporation. CD34+ PBPC were isolated with a high-gradient magnetic cell sorting system (MACS), and then were transfected with supernatant of retrovirus containing human ALDH-3 and MDR1 cDNA. PCR, RT-PCR, Southern blot, Northern blot, FACS, and MTT assay were used to evaluate the transfection and expression of the transgene in target cells.

RESULTS

The bicistronic retroviral vector construction was verified by PCR and restriction endonuclease analysis. Dual drug resistance genes were integrated into the genomic DNA of CD34+ PBPC and expressed efficiently. The efficiency of gene transfection in CD34+ PBPC was tested to be 18 % on colonies. Nested PCR and Neor rescue assay indicated that no helper virus was present in this system. Compared with the untransduced cells, transgene recipient cells conferred 4.5-fold resistance to 4-HC, 6.6-fold and 7.8-fold resistance to P-glycoprotein effluxed drug, vincristine and daunorubicin, respectively.

CONCLUSION

Efficient transduction of two different types of drug resistance genes into human peripheral blood hematopoietic progenitor cells and the co-expression may decrease cumulative myelosuppression of combination chemotherapy.

[Effects of angiotensin II on proliferation and expression of interleukin-6 of human kidney fibroblasts]

OBJECTIVE

To investigate the effects of Angiotensin(Ang) II on the proliferation and expression of Interleukin (IL)-6 in human kidney fibroblasts(KFB).

METHODS

The human KFB were cultured and identified, the proliferation of KFB was measured by MTT, and the level of IL-6 was measured by radioimmunoassay(RIA).

RESULTS

Angiotensin II could stimulate the proliferation of KFB and enhance the expression of IL-6 in protein level on KFB.

CONCLUSION

Angiotensin II can stimulate KFB's proliferation and enhance the expression of IL-6 of KFB. These findings suggest that Ang II might play a part in the mechanisms for modulating tubulointerstitial changes and induceing renal fibrosis.

[A study of Humphrey three zone screening to detect visual field of the patients with pituitary macroadenomas]

OBJECTIVE

To evaluate the clinical application of Humphrey three zone screening in detecting the visual field of the patients with pituitary macroadenomas (PMA).

METHODS

There were two groups in the study. The PMA group: 128 PMA cases were selected who had symptoms of visual problem and been diagnosed with computer tomography (CT) or magnetic resonance (MR) and without apparent opacity of refractive medium. The low myopia group: thirty cases with low myopia and without other eye diseases were included. Humphrey three zone screening method was used to detect the 76-points in the central 30 degree visual fields of the patients of the two groups.

RESULTS

In PMA group, 99.2% of the 128 patients and 87.1% of their eyes had visual field defect. 86.7% of the patients had the visual field defect mainly located at the temporal side and showed or tended to have a medial vertical limit. In detecting abnormality of the patients, three zone screening test had a sensitivity of 99.2% (percent of cases with true visual field defect identified by the field test). The mean test duration of each eye is (5.8 +/- 2.2) minutes. In low myopia group, two eyes of two patients had visual field defect. In testing the normal group, three zone screening test had a specificity of 93.3% (percent of cases without true visual field defect appropriately identified by the field test).

CONCLUSION

Humphrey three zone screening has very high sensitivity and specificity in detecting visual field, and it is simple, fast and practical for detecting the visual field of the patients with PMA. It plays an important role in implying diagnosis and avoiding misdiagnosis of PMA.

Development of a low-cost microfluidic capillary-electrophoresis system coupled with flow-injection and sequential-injection sample introduction (review)

Microfabrication techniques used for the production of MEMS (micro electro-mechanical systems) have been successfully used to produce highly efficient microfluidic capillary electrophoresis chip systems. A limitation of this approach are the difficulties associated with the creation of the micrometer-sized structures in glass or other substrates, which currently involve specialized and expensive lithographic and etching processes. A further limitation is that hitherto most microfluidic chips are not designed for continuous introduction of a series of different samples, which limits the overall throughput of such systems. This article reviews the development of a microfluidic system for rapid CE separations, produced at a low cost of less than a dollar each, using equipment and materials readily available in the ordinary laboratory. Applications of the system, after coupling to flow-injection and/or sequential-injection sample introduction, for the determination of FITC-labeled amino acids by laser-induced fluorescence, trace metals by chemiluminescence, carbohydrates by amperometry, and inorganic and organic anions by indirect UV absorbance are exemplified to illustrate the performance and versatility of the microfluidic system.

Clinical retrospective and comparative study on diaphragm injuries in 46 cases

OBJECTIVE

To explore a way of guiding diagnosis and treatment of blunt and penetrating diaphragm injuries.

METHODS

According to injury violence, 46 chest trauma patients with diaphragm rupture were divided into two groups: a blunt injury group and a penetrating injury group. The injury condition and trauma scores between the two groups were compared and analyzed.

RESULTS

The incidence of blunt diaphragm injuries was lower than that of penetrating injuries (1.78% vs 8.53%, P <0.05). In the blunt injury group most patients had multiple injuries. Penetrating injuries developed more quickly than blunt injuries, and resulted in hemorrhagic shock in the early period. Trauma scores showed that there was no significant difference in the Revised Trauma Score (RTS), the Injury Severity Score (ISS) and thoracic Abbreviated Injury Scale (AIS) between the two groups (P<0.05), but the blunt injury group had lower Glasgow Coma Scale (GCS) and abdominal AIS than the penetrating group (P<0.0 5).

CONCLUSIONS

Blunt and penetrating diaphragm injuries have different clinical characteristics. So they should be dealt with differently to reduce the incidence of complication and improve prognosis.

A histone fold TAF octamer within the yeast TFIID transcriptional coactivator

Gene activity in a eukaryotic cell is regulated by accessory factors to RNA polymerase II, which include the general transcription factor complex TFIID, composed of TBP and TBP-associated factors (TAFs). Three TAFs that contain histone fold motifs (yTAF17, yTAF60 and yTAF61) are critical for transcriptional regulation in the yeast Saccharomyces cerevisiae and are found in both TFIID and SAGA, a multicomponent histone acetyltransferase transcriptional coactivator. Although these three TAFs were proposed to assemble into a pseudooctamer complex, we find instead that yTAF17, yTAF60 and yTAF61 form a specific TAF octamer complex with a fourth TAF found in TFIID, yTAF48. We have reconstituted this complex in vitro and established that it is an octamer containing two copies each of the four components. Point mutations within the histone folds disrupt the octamer in vitro, and temperature-sensitive mutations in the histone folds can be specifically suppressed by overexpressing the other TAF octamer components in vivo. Our results indicate that the TAF octamer is similar both in stoichiometry and histone fold interactions to the histone octamer component of chromatin.

On-line incorporation of cloud point extraction to flow injection analysis

The on-line incorporation of cloud point extraction (CPE) to flow injection analysis (FIA) is demonstrated for the first time. The technical difficulties of inducing the cloud point phenomenon, separating the surfactant-rich phase from the aqueous phase, and detecting trace amounts of analyte(s) in the presence of the highly scattering surfactant medium in an on-line FIA system were resolved by the following: (1) mixing the sample solution containing the analyte(s) and CPE surfactant with an appropriate salting-out agent, (2) using a collection column to entrap the analyte-containing surfactant aggregates, and (3) employing the peroxyoxalate chemiluminescence reaction for the sensitive and selective determination of the analyte(s) in the presence of surfactant micelles. The figures of merit for the determination of coproporphyrin in pretreated urine samples were as follows: precision, 1.1-2.2% (RSD); limit of detection, 2.0 microg/L; and the calibration curve was linear from 46 to 2319 (micro/L (r = 0.9996).

Preparation and characterization of biodegradable copolyester-starch based foams

Regular (25% amylose) and waxy corn starches blended to various ratios with Eastar Bio Copolyester 14766 (EBC) were extruded into loose-fill foams using a twin screw extruder. Included in this study were two types of corn starch, three levels of EBC content, and three levels of starch moisture content. Waxy starch produced foams with greater radial expansions and lower unit and bulk densities than regular starch. Regular starch foams had lower water solubility indices (WSIs) than waxy starch foams. Foams made of both types of starch possessed similar mechanical properties. No differences were observed in compressibilities and spring indices of either waxy or regular starch foams. Higher levels of EBC addition resulted in less radial expansion and higher unit and bulk densities. Foams made with 10% EBC had higher compressibility than foams containing 25% EBC. Spring indices of single-piece samples and compressibilities and spring indices of bulk samples were not affected by the differences in the level of EBC addition. At 19% and 22% of moisture contents, foams had greater radial expansion than at 25% moisture content. Unit and bulk densities were not affected by variations in moisture content. At 22% moisture content, a lower WSI of 18.5% was obtained. At 22% moisture content, softer foams were produced. At all three levels of moisture content, no differences were detected in the spring indices.

Optical properties of a new two-photon absorbing chromophore

A new dye, trans-4-[p-(pyrrolidinyl)styryl]-N-methylpyridinium iodide, has been synthesized, and the two-photon-absorption (TPA), TPA-induced frequency upconversion emission, and two-photon-pumped (TPP) frequency upconverted lasing properties of this new dye were experimentally studied. This new dye has a moderate TPA cross section of varsigma(2) = 5.7 x 10(-48) (cm(4) s(-1))/photon at 1064 nm but exhibits high lasing efficiency. The slope efficiency of the TPP cavity laser with this new dye as the laser medium is 1.6%.

Micelle-mediated extraction and preconcentration of ginsenosides from Chinese herbal medicine

The feasibility of employing micelle-mediated extraction as an alternative and effective method for the solubilization, purification and/or preconcentration of active ingredients from herbal products is demonstrated for the first time using the root of American ginseng as a model. When compared to methanol and water, an aqueous surfactant solution containing 10% Triton X-100 yielded faster kinetics and higher recovery for the extraction of various ginsenosides. An experimental design approach (uniform design) was demonstrated as a novel and useful method for the optimization of experimental factors involved in the micelle-mediated extraction process. For the preconcentration of ginsenosides prior to chromatographic determination, a salting-out agent (sodium sulfate) was employed to make the efficient cloud point extraction of both hydrophobic and hydrophilic ginsenosides into the surfactant-rich phase possible, as well as to increase the preconcentration factor by reducing the volume of the surfactant-rich phase.

Establishment and chimera analysis of 129/SvEv- and C57BL/6-derived mouse embryonic stem cell lines

Hundreds of new mutant mouse lines are being produced annually using gene targeting and gene trap approaches in embryonic stem (ES) cells, and the number is expected to continue to grow as the human and mouse genome projects progress. The availability of robust ES cell lines and a simple technology for making chimeras is more attractive now than ever before. We established several new ES cell lines from 129/SvEv and C57BL/6 mice and tested their ability to contribute to the germline following blastocyst injections and/or the less expensive and easier method of morula-ES cell aggregation. Using morula aggregation to produce chimeras, five newly derived 129/SvEv and two C57BL/6 ES cell lines tested at early passages were found to contribute extensively to chimeras and produce germline-transmitting male chimeras. Furthermore, the two 129S/vEv ES cell lines that were tested and one of the C57BL/6 ES cell lines were able to maintain these characteristics after many passages in vitro. Our results indicate that the ability of ES cells to contribute strongly to chimeras following aggregation with outbred embryos is a general property of early passage ES cells and can be maintained for many passages. C56BL/6-derived ES cell lines, however, have a greater tendency than 129-derived ES cell lines to lose their ability to colonize the germline.

Sequence of genome segments 1, 2, and 3 of the grass carp reovirus (Genus Aquareovirus, family Reoviridae)

The genome segments 1, 2, and 3 of the grass carp reovirus (GCRV), a tentative species assigned to genus Aquareovirus, family Reoviridae, were sequenced. The respective segments 1, 2, and 3 were 3949, 3877, and 3702 nucleotides long. Conserved motifs 5' (GUUAUUU) and 3' (UUCAUC) were found at the ends of each segment. Each segment contains a single ORF and the negative strand does not permit identification of consistent ORFs. Sequence analysis revealed that VP2 is the viral polymerase, while VP1 might represent the viral guanylyl/methyl transferase (involved in the capping process of RNA transcripts) and VP3 the NTPase/helicase (involved in the transcription and capping of viral RNAs). The highest amino acid identities (26-41%) were found with orthoreovirus proteins. Further genomic characterization should provide insight about the genetic relationships between GCRV, aquareoviruses, and orthoreoviruses. It should also permit to precise the taxonomic status of these different viruses.

[Differentiation of achondroplasia and other similar genetic dwarfism by FGFR3 gene analysis]

OBJECTIVE

To study the gene mutation of Chinese patients with achondroplasia(ACH) and to set up a simple and rapid molecular diagnostic method to differentiate ACH from other similar genetic dwarfism.

METHODS

The specific fragment of fibroblast growth factor receptor 3(FGFR3) transmembrane domain was amplified from dried blood spots of 21 patients with ACH and 6 suspicious patients with ACH by polymerase chain reaction, then mutation was screened and detected by restrictive enzyme analysis, single strand conformation polymorphism(SSCP) and denaturing gradient gel electrophoresis(DGGE).

RESULTS

One out of 6 suspicious cases was ACH and 5 were pseudoachondroplasia(PSACH). Twenty-one out of 22 patients with ACH bore a G to A transition at nucleotide 1138 and 1 bore a G to C transversion at this same position.

CONCLUSION

The nucleotide 1138 of FGFR3 gene is also the hotspot of mutation in Chinese patients with ACH. A simple and rapid molecular diagnostic method has been set up to differentiate ACH from other similar genetic dwarfism.

[The detection of disparity evoked potentials in anisometropes]

OBJECTIVE

To investigate the affection of anisometropia on stereopsis and its mechanism.

METHODS

A new set of static random-dot stereograms was utilized as a stimulus to elicit evoked potentials in 20 anisometropes and 40 normal subjects.

RESULTS

Under the stimulus of different degrees of disparity in anisometropes, the P(250) waves related to stereopsis could be recorded. However, the percentage of their P(250) wave amplitude over the plane figure was significantly lower than that of normal persons (P < 0.05). The P(250) wave mean amplitude of severe anisometropes (aniseikonia >or= 5%) in fine disparity (14' and 23') was lower than that in mild anisometropes (aniseikonia < 5%, P < 0.05).

CONCLUSIONS

Anisometropia may affect and disturb the stereopsis. The degree of disturbance is related to the degree of anisometropia. The higher the degree of anisometropia, the lower the amplitude of the P(250) potential, and the main defect is at the part of fine disparity.

Cartilage-reactive T cells in rheumatoid synovium

Rheumatoid arthritis (RA) is an inflammatory polyarthritis genetically linked to HLA-DR4 and related haplotypes. RA synovial tissue is characterized by T cell infiltration and activation of macrophage-like cells, strongly implicating a T cell-antigen-presenting cell (APC) interaction in RA pathogenesis. To investigate the nature of the antigens driving the T cell response, synovial tissue was obtained from a patient with chronic RA and T cells were enriched. These T cells were stimulated by endogenous APC from the same synovial tissue. The T cell lines were subsequently evaluated for responsiveness to autologous APC and cartilage antigens. Specific proliferative responses to autologous APC which were enhanced by cartilage extract were seen. Immunomagnetic bead selection and RT-PCR was used to identify TCR alphabeta pairs which appeared to respond to antigen(s) in the cartilage extract. T cell clones derived from the same joint were shown to release IL-2 in response to the cartilage extract and expressed a related TCR. With these experiments we have shown direct evidence that autoreactive T cells are found within the inflamed rheumatoid synovium and, further, that the antigens driving these T cells are cartilage derived. Since the antigens recognized by these populations of T cells are found within cartilage our data provides evidence that RA pathology could be related to a self-driven autoimmune response to cartilage proteins.

The resonant recognition model (RRM) predicts amino acid residues in highly conserved regions of the hormone prolactin (PRL)

The resonant recognition model (RRM) is a model which treats the protein sequence as a discrete signal. It has been shown previously that certain periodicities (frequencies) in this signal characterise protein biological function. The RRM was employed to determine the characteristic frequencies of the hormone prolactin (PRL), and to identify amino acids ('hot spots') mostly contributing to these frequencies and thus proposed to mostly contribute to the biological function. The predicted 'hot spot' amino acids, Phe-19, Ser-26, Ser-33, Phe-37, Phe-40, Gly-47, Gly-49, Phe-50, Ser-61, Gly-129, Arg-176, Arg-177, Cys-191 and Arg-192 are found in the highly conserved amino-terminal and C-terminus regions of PRL. Our predictions agree with previous experimentally tested residues by site-direct mutagenesis and photoaffinity labelling.

[Difluoromethylornithine synergizes with antisense bcl-2 RNA in the induction of apoptosis of HL60 cells]

OBJECTIVE

To study the combined effect of difluoromethylornithine (DFMO) and bcl-2 antisense RNA in the induction of apoptosis of HL60 cells.

METHODS

HL60 cells were transfected with recombinant retroviral vector expressing bcl-2 antisense RNA. The growth characteristics of transfectants were studied by morphological observation, growth curve, FCM analysis, colony formation in soft agar, DNA electrophoresis, molecular hybridization and immunocytochemical staining.

RESULTS

The recombinant retroviral vectors expressing bcl-2 antisense RNA and the cell line producing recombinant virus were constructed. Although the expression of bcl-2 at mRNA and protein levels in the HL60 cells transfected with antisense bcl-2 were down-regulated, there was no change in cell growth, cell cycles and expression of ornithine decarboxylase (ODC) compared with the parental cells albeit some decrease in colony formation. In addition, transfection with antisense bcl-2 did not induce marked apoptosis whereas treatment of the transfectant with low concentration (0.2 mmol/L) of DFMO resulted in enhanced expression inhibition of bcl-2 protein, inhibition of cell growth and induction of apoptosis.

CONCLUSION

DFMO synergizes with antiense bcl-2 RNA in the induction of apoptosis of HL60 cells.

[Analysis of chromosomal karyotypes in 300 fetal blood samples during the second and third trimesters of gestation]

OBJECTIVE

To analyze the fetal chromosomal karyotypes from the blood samples obtained by cordocenteses during the second and third trimesters, and to investigate the types of chromosomal abnormalities, as well as the relationship between the abnormal karyotypes and the indications of prenatal diagnosis.

METHODS

Cordocenteses were performed in 300 pregnant women with different indications for prenatal diagnosis during the 18 to 38 gestational weeks, and fetal chromosomal karyotypes were examined.

RESULTS

Twenty three chromosomal abnormalities(7.7%) were checked out. In the second trimester, there were 15 abnormalities in 174 samples(8. 6%); whereas in the third trimester, it was 8 out of 126(6.3%), P=0. 77. Trisomy, the leading abnormality, consisted of 60.9%(14/23) of all abnormalities and 9 out of 14 were trisomy 21, which was 39. 1%(9/23). In those aged over 35 years, trisomy 21 was detected in 5 of 92(5.4%), and in the age under 35 years, it was 4 out of 208(1. 9%), P=0.26. Thirty three women had the history of giving a birth of trisomy 21 previously, this time, however, no one was recurrent. Highest chromosomal aberration rate, 26.3%(5/19), was detected in the fetuses with intrauterine growth retardation(IUGR), and all were trisomy. Balanced translocation was found in 5 fetuses (1 associated with Robertsonian translocation), which was 21.7%(5/23).

CONCLUSION

During the second and third trimesters, the rate of chromosomal abnormality is 7.7% in those fetuses who have maternal indications for prenatal diagnosis. trisomy, especially trisomy 21, is the most common abnormal karyotype found in these periods and in advanced maternal age, as well as in severe IUGR.

Targeted deletion of the tub mouse obesity gene reveals that tubby is a loss-of-function mutation

The mouse tubby phenotype is characterized by maturity-onset obesity accompanied by retinal and cochlear degeneration. A positional cloning effort to find the gene responsible for this phenotype led to the identification of tub, a member of a novel gene family of unknown function. A splice defect mutation in the 3' end of the tub gene, predicted to disrupt the C terminus of the Tub protein, has been implicated in the genesis of the tubby phenotype. It is not clear, however, whether the Tub mutant protein retains any biological activity, or perhaps has some dominant function, nor is it established that the tubby mutation is itself responsible for all of the observed tubby phenotypes. To address these questions, we generated tub-deficient mice and compared their phenotype to that of tubby mice. Our results demonstrate that tubby is a loss-of-function mutation of the tub gene and that loss of the tub gene is sufficient to give rise to the full spectrum of tubby phenotypes. We also demonstrate that loss of photoreceptors in the retina of tubby and tub-deficient mice occurs by apoptosis. In addition, we show that Tub protein expression is not significantly altered in the ob, db, or melanocortin 4 receptor-deficient mouse model of obesity.

Influence of fetal to neonatal transition on nitric oxide synthase expression in the nucleus tractus solitarius in sheep

Transition from fetal to newborn life is accompanied by a marked rise in circulating norepinephrine (NE) concentrations though arterial blood pressure does not substantively change. Nitric oxide (NO) plays an important role in the central regulation of sympathetic tone in the nucleus tractus solitarius (NTS) and neuronal NO synthase (nNOS) expression is functionally regulated in the brain. The purpose of these studies was to determine the influence of transition at birth on nNOS expression in the brainstem nuclei, particularly in the NTS, associated with changes in arterial pressure and plasma NE concentration. Experiments were performed using time-dated gestational ewes with twin fetuses. Arterial blood pressure was recorded and arterial blood NE concentrations were measured in the term fetus (gestational 147-148 days) and newborn lambs (4 h of postnatal age). The fetal and newborn animals were then perfused with 4% paraformaldehyde. Sections of the medulla were examined by using both immunolabeling with a polyclonal antibody directed against nNOS and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry, a marker for expression of nNOS. Micrographs were quantified using a microscope with reticule grid to measure the number of positive cells containing color staining in the brainstem nuclei. Plasma NE concentration in the newborn was more than two-fold greater compared to fetal values but mean arterial blood pressure was similar between fetus and newborn. The nNOS positive cells and NADPHd positive cells were significantly increased in the medial NTS (mNTS) of the newborn compared to fetus. nNOS immunoreactivity and NADPHd reactivity tended to increase in the rostral ventral medulla (RVM) in newborn, but were not altered in other brainstem nuclei during the transition from fetal to newborn life. The results suggest that nNOS expression in the mNTS is predominately enhanced at 4 h of neonatal age vs. the term fetus. We conclude that elevated circulating NE is associated with up-regulation of nNOS in the mNTS which may serve a protective role in central regulation of neonatal arterial blood pressure.