Woven silk fabric-reinforced silk nanofibrous scaffolds for regenerating load-bearing soft tissues

Although three-dimensional (3-D) porous regenerated silk scaffolds with outstanding biocompatibility, biodegradability and low inflammatory reactions have promising application in different tissue regeneration, the mechanical properties of regenerated scaffolds, especially suture retention strength, must be further improved to satisfy the requirements of clinical applications. This study presents woven silk fabric-reinforced silk nanofibrous scaffolds aimed at dermal tissue engineering. To improve the mechanical properties, silk scaffolds prepared by lyophilization were reinforced with degummed woven silk fabrics. The ultimate tensile strength, elongation at break and suture retention strength of the scaffolds were significantly improved, providing suitable mechanical properties strong enough for clinical applications. The stiffness and degradation behaviors were then further regulated by different after-treatment processes, making the scaffolds more suitable for dermal tissue regeneration. The in vitro cell culture results indicated that these scaffolds maintained their excellent biocompatibility after being reinforced with woven silk fabrics. Without sacrifice of porous structure and biocompatibility, the fabric-reinforced scaffolds with better mechanical properties could facilitate future clinical applications of silk as matrices in skin repair.

Meta-analysis of associations between the TP53 Arg72Pro polymorphism with risk of head and neck carcinomas based on case-control studies

Genetic factors have been shown to play a role in the development of head and neck cancers (HNCs). However, studies investigating the association between the TP53 Arg72Pro polymorphism and HNCs susceptibility have yielded conflicting results. Hence, we performed a meta-analysis of all eligible studies (up to January 1, 2012) to derive a more precise estimation of this association in order to increase understanding of the possible risk factors of HNCs. Twenty-seven case-control studies involving 3966 cases and 4387 controls were included in our analysis. Overall, no evidence of association was observed between the TP53 Arg72Pro single nucleotide polymorphism (SNP) and the risk of HNCs in any genetic model (Arg/Arg vs Pro/Pro: odds ratio (OR) = 0.83, 95% confidence interval (CI): 0.65-1.06; Arg/Pro vs Pro/Pro: OR = 0.88, 95%CI= 0.70-1.10; Arg/Arg+Arg/Pro vs Pro/Pro: OR = 0.87, 95%CI= 0.70-1.09; Arg/Arg vs Arg/Pro+Pro/Pro: OR = 0.95, 95%CI= 0.82-1.11). Nevertheless, the TP53 Arg72Pro polymorphism shows diverse effects across different subtypes of HNCs. For example, there was a lack of association of this polymorphism with oral cavity cancer, whereas a significant association with nasopharyngeal cancer was observed. Results of this meta-analysis suggest that the TP53 Arg72Pro polymorphism might have different effects on the risk of various subtypes of HNCs.

Trajectory planning of a robot for lower limb rehabilitation

We introduce a method for lower-limb physical rehabilitation by means of a robot that applies preliminary defined forces to a patient's foot while moving it on a preliminary defined trajectory. We developed a special musculoskeletal model that takes into consideration the generated muscle forces of 27 musculotendon actuators and joint stiffness of the leg and allows the calculation of the motion trajectory of the robot and the forces that the robot needs to apply to the foot in each moment of the therapeutic exercise. Robotic treatment programs are customized for the individual patient by using a genetic algorithm (GA) that refers to the musculoskeletal model and calculates the parameters of the spline curves of the motion trajectory of the robot and forces acting on the foot.

Robot-aided rehabilitation task design for inner shoulder muscles

In this paper, we propose a simultaneous design method of motion and external force trajectories for shoulder inner muscles in the robot-aided rehabilitation system, based on a biomechanical analysis of patient's body. The rehabilitation efficiency evaluation function was maximized by Genetic Algorithm (GA), where the structure of spline curves parameters are pre-defined, and the structural parameters are explored to design smooth rehabilitation motion and external force trajectories.

Occupational contact dermatitis (drug-induced medicamentosa): six case reports

We report six patients who had dermatitis after contacting certain chemical substances (one worker with contact 1-chloromethyl naphthalene and five with contact Hydroxy-phthalimide). They appeared like drug-induced erythma multiforme, bullosa epidermalysis from the point of contact gradually spreading to the whole body, combining high temperature, digestive system dysfunction, such as liver dysfunction etc. We can call this occupational drug-induced medicamentosa. The course of dermatosis diseases is 1 - 2 months. Hormone and sustaining treatment may be effective. We discuss chemistry substance, clinical presentation, diagnoses, treatment and relevant prognosis.

Structural biology of RNA silencing and its functional implications

We outline structure-function contributions from our laboratories on protein-RNA recognition events that monitor siRNA length, 5 -phosphate and 2-nucleotide 3 overhangs, as well as the architecture of Argonaute, its externally bound siRNA complex, and Argonaute-based models involving guide-strand-mediated mRNA binding, cleavage, and release.

Mitochondrial DNA deletions in primate embryonic and adult stem cells

Mitochondrial DNA (mtDNA) mutations occur naturally in skeletal muscle fibers from aged rhesus macaques. In addition, mtDNA mutations have been observed in germinal vesicle oocytes from fertile monkeys. The goal of this study was to determine whether the rhesus macaque mitochondrial common deletion was present in oocytes and embryos generated by in-vitro embryo production (IVP), as well as in rhesus adult and embryonic stem cell lines. The rhesus common deletion was detected in IVP-generated embryos, three IVP-derived embryonic stem cell lines (ORMES 1, 2 and 7), one in-vivo-derived embryonic stem cell line (R4) and multiple passages of an adult bone marrow stromal cell (BMSC) line. Mitochondrial DNA from an adult adipose stromal cell (ATSC) line was compared with mtDNA from an immortalized line transfected with a retroviral vector expressing telomerase, ATSC-TERT. Multiple passages of the ATSC line harboured a dramatically higher level of the rhesus common deletion than the immortalized ATSC-TERT line. Accumulation of mtDNA mutations in oocytes, embryos and subsequent embryonic stem cell lines, as well as adult stem cell lines, may contribute to mitochondrial dysfunction, and thereby impair ATP production. The authors believe this information establishes a compelling argument for the parallel development of embryonic stem cell technology in non-human primates and humans.

Cloning and molecular characterization of three novel LMW-i glutenin subunit genes from cultivated einkorn (Triticum monococcum L.)

Three novel low molecular weight (LMW) glutenin subunits from cultivated einkorn (Triticum monococcum L., A(m)A(m), 2n = 2x = 14) were characterized by SDS-PAGE and molecular weights determined by MALDI-TOF-MS. Their coding genes were amplified and cloned with designed AS-PCR primers, revealing three complete gene sequences. All comprised upstream, open reading frame (ORF), downstream and no introns were present. The deduced amino acid sequences showed that all three genes, named as LMW-M1, LMW-M3 and LMW-M5, respectively, belonged to the LMW-i type subunits with the predicted molecular weight between 38.5206 and 38.7028 kDa. They showed high similarity with other LMW-i type genes from hexaploid bread wheats, but also displayed unique features. Particularly, LMW-M5 subunit contained an extra cysteine residue in the C-terminus except for eight conserved cysteines, which resulted from a single-nucleotide polymorphism (SNP) of the T-C transition, namely arginine --> cysteine substitution at position 242 from the N-terminal end. This is the first report that the LMW-i subunit contained nine cysteines residues that could result in a more highly cross-linked and more elastic glutenin suggesting that LMW-M5 gene may associates with good quality properties. In addition, a total of 25 SNPs and one insertions/deletions (InDels) were detected among three LMW-i genes, which could result in significant functional changes in polymer formation of gluten. It is anticipated that these SNPs could be used as reliable genetic markers during wheat quality improvement. The phylogenetic analysis indicated that LMW-i type genes apparently differed from LMW-m and LMW-s type genes and diverged early from the primitive LMW-GS gene family, at about 12.92 million years ago (MYA) while the differentiation of A(m) and A genomes was estimated at 3.98 MYA.

Ectopic expression of the human adenine nucleotide translocase, isoform 3 (ANT-3). Characterization of ligand binding properties

The adenine nucleotide translocase (ANT) is a key component in maintaining cellular energy homeostasis, and has also been implicated in formation of the mitochondrial permeability transition pore. Human ANT-3 was cloned from a human heart cDNA library and expressed as a histidine-tagged fusion protein in the mitochondria of the Trichoplusia ni. cell line. Overexpression resulted in a concomitant decrease in the endogenous ANT content, allowing for the characterization of binding of known ANT ligands to the human protein. Binding affinities for bongkrekic acid (BKA), ADP, and atractyloside (ATR) were measured in mitochondria from the human ANT-3 expressing cell line, and compared to similar preparations from bovine heart mitochondria by use of a novel radioiodinated derivative of ATR. Binding to ANT-3 by the high affinity inhibitors BKA and ATR, as well as the lower affinity natural ligand ADP, was similar to that measured in bovine heart mitochondria, and to that previously reported for mammalian heart mitochondria. Characterizations such as these of human ANT isoforms may lead to drug development for enhanced mitochondrial function and cellular viability.

Serum-free culture of rhesus monkey embryonic stem cells

Previous studies have shown that the maintenance and proliferation of undifferentiated rhesus monkey embryonic stem (rES) cells requires medium supplemented with fetal bovine serum (FBS). Due to the uncharacterized composition and variation in serum nature, the present study aimed to replace the serum-containing medium with a serum-free medium in the rES cell culture. The results showed that after the initial 48-h culture in the routinely used serum-containing medium, rES cells can grow and proliferate for a prolonged period in the serum-free medium composed of DMEM supplemented with a cocktail of BSA, IGF-1, TGF-alpha, bFGF, aFGF, estradiol, and progesterone. rES cells cultured in the serum-free medium maintained high level of alkaline phosphatase activity and OCT4 level. There was no indication of differentiation as judged by the marker gene expression of all three embryonic germ layers and trophoblast. In addition, serum-free culture would not affect the passage capacity and differentiation potential of rES cells. This work will facilitate the future study of induced differentiation of rES cells and other applications.

The platelet-activating factor receptor protects epidermal cells from tumor necrosis factor (TNF) alpha and TNF-related apoptosis-inducing ligand-induced apoptosis through an NF-kappa B-dependent process

A number of chemical mediators can induce human keratinocytes and epidermal-derived carcinomas to undergo apoptosis, or programmed cell death. Recent evidence suggests pro-inflammatory cytokines, such as interleukin-1 beta or transforming growth factor alpha, protects carcinomas from numerous pro-apoptotic stimuli. Platelet-activating factor (1-alkyl-2-acetyl-3-glycerophosphocholine; PAF) is a lipid mediator with pro-inflammatory effects on numerous cell types. Although PAF can be metabolized to other bioactive lipids, the majority of PAF effects occur through activation of a G protein-coupled receptor. Using a model system created by retroviral transduction of the PAF receptor (PAF-R) into the PAF-R-negative human epidermal cell line KB and the PAF-R-expressing keratinocyte cell line HaCaT, we now demonstrate that activation of the epidermal PAF-R results in protection from apoptosis induced by tumor necrosis factor (TNF) alpha or TNF-related apoptosis-inducing ligand. The PAF-mediated protection was inhibited by PAF-R antagonists, and protection did not occur in PAF-R-negative KB cells. Additionally, we show protection from TNFalpha- or TRAIL-induced apoptosis by PAF-R activation is dependent on the transcription factor nuclear factor (NF)-kappa B, because PAF-R activation-induced NF-kappa B and epidermal cells transduced with a super-repressor form of inhibitor kappa B were not protected by the PAF-R. These studies provide a mechanism whereby the epidermal PAF-R, and possibly other G protein-coupled receptors, can exert anti-apoptotic effects through an NF-kappa B-dependent process.

Changes of urinary steroid conjugates and gonadotropin excretion in the menstrual cycle and pregnancy in the Yunnan snub-nosed monkey (Rhinopithecus bieti)

The Yunnan snub-nosed monkey (Rhinopithecus bieti) is one of the most endangered species in the world, and it is endemic to China. According to our knowledge, there was no information on reproduction for this species. The present study was designed to understand the characteristics of reproductive hormone secretion during the menstrual cycle and pregnancy of this species by monitoring urinary estrone conjugate (E1C), pregnanediol-3-glucuronide (PdG), bioactive follicle-stimulating hormone (FSH), and luteinizing hormone (LH). The urine samples were collected each day from four adult females for eight menstrual cycles, and once in 3 days during pregnancy (three full-term pregnancies, one mid-term abortion). The steroid conjugate was tested by radioimmunoassays (RIAs), and bioactive FSH and LH levels were measured in vitro by the sensitive bioassays granulosa cell aromatize bioassay (GAB) and rat interstitial cell testosterone (RICT), respectively. The results showed that: 1) E1C presented a preovulatory peak (183.9 +/- 8.6 ng/mgCr) followed by a definite elevation of PdG; 2) PdG in the luteal phase (754.4 +/- 30.6 ng/mgCr) was three- to fivefold higher than during the corresponding follicular phase (198.3 +/- 11.4 ng/mgCr); 3) the peaks of bio-LH and bio-FSH were on the same day, while the E1C peak was 1 or 2 days before the peaks for these two hormones; 4) bio-FSH levels were higher in the follicular phase than in the luteal phase, and bio-LH levels elevated slightly in the luteal phase; 5) the mean cycle length was 23.6 +/- 3.5 days (n = 3) based upon successive urinary LH peaks; 6) based on the interval from the day of E1C peak to the day of parturition, the gestation was 203.7 +/- 2.5 days (n = 3); and 7) both E1C and PdG increased and remained high after pregnancy, with a sharp decrease in basal levels following parturition or mid-term abortion. The results suggested that the pattern of reproductive hormones for R. bieti is similar to that of other Old World monkeys, but the concentration of the hormones is different from that of other species. This species has a longer progestation period, which may be related to its classification status.

Optical tomographic imaging of dynamic features of dense-scattering media

Methods used in optical tomography have thus far proven to produce images of complex target media (e.g., tissue) having, at best, relatively modest spatial resolution. This presents a challenge in differentiating artifact from true features. Further complicating such efforts is the expectation that the optical properties of tissue for any individual are largely unknown and are likely to be quite variable due to the occurrence of natural vascular rhythms whose amplitudes are sensitive to a host of autonomic stimuli that are easily induced. We recognize, however, that rather than frustrating efforts to validate the accuracy of image features, the time-varying properties of the vasculature can be exploited to aid in such efforts, owing to the known structure-dependent frequency response of the vasculature and to the fact that hemoglobin is a principal contrast feature of the vasculature at near-infrared wavelengths. To accomplish this, it is necessary to generate a time series of image data. In this report we have tested the hypothesis that through analysis of time-series data, independent contrast features can be derived that serve to validate, at least qualitatively, the accuracy of imaging data, in effect establishing a self-referencing scheme. A significant finding is the observation that analysis of such data can produce high-contrast images that reveal features that are mainly obscured in individual image frames or in time-averaged image data. Given the central role of hemoglobin in tissue function, this finding suggests that a wealth of new features associated with vascular dynamics can be identified from the analysis of time-series image data.

Prevalence of hepatitis E virus antibodies in Canadian swine herds and identification of a novel variant of swine hepatitis E virus

Swine hepatitis E virus is a newly identified potentially zoonotic virus from pigs of particular concern for possible direct transmission to a human xenotransplant recipient by organ transplantation. In the present study, prevalence of serum antibodies to hepatitis E virus was examined in Canadian swine herds. A total of 998 serum samples collected from 6-month-old healthy slaughter hogs were examined by enzyme immunoassay and Western blot analysis for antibodies to the recombinant open reading frame 3 (ORF3) protein of hepatitis E virus expressed in Escherichia coli. These samples represented more than 80 different swine production units from five major swine-producing provinces across Canada. From this study, 594 samples (59.4%) were found to be positive for hepatitis E virus antibody. The seroprevalence was higher in Quebec (88.8%) and Ontario (80.1%) than in Alberta and Saskatchewan (38.3%). By PCR using a pair of oligonucleotide primers deduced from the ORF2 sequence of human hepatitis E virus, a specific hepatitis E virus sequence was recovered from feces of pigs. The nucleotide sequence identity between the U.S. swine hepatitis E virus and the Canadian isolate (SK3) was only 85.8%, suggesting that genotypic variations may exist in swine hepatitis E virus in North America. Among 165 serum samples collected from humans in Saskatchewan, 2.4% were found to be positive for antibodies to the hepatitis E virus ORF3 protein. Our data indicate that hepatitis E virus is highly prevalent in commercial swine populations in Canada and support the suggestion that the swine hepatitis E virus may be an important zoonotic agent for humans.

Influence of Systematic Errors in Reference States on Image Quality and on Stability of Derived Information for dc Optical Imaging

Optical measurements of tissue can be performed in discrete, time-averaged, and time-varying data collection modes. This information can be evaluated to yield estimates of either absolute optical coefficient values or some relative change in these values compared with a defined state. In the case of time-varying data, additional analysis can be applied to define various dynamic features. Here we have explored the accuracy with which such information can be recovered from dense scattering media using linear perturbation theory, as a function of the accuracy of the reference medium that serves as the initial guess. Within the framework of diffusion theory and a first-order solution, we have observed the following inequality regarding the sensitivity of computed measures to inaccuracy in the reference medium: Absolute measures ? relative measures > dynamic measures. In fact, the fidelity of derived dynamic measures was striking; we observed that accurate measures of dynamic behavior could be defined even if the quality of the image data from which these measures were derived was comparatively modest. In other studies we identified inaccuracy in the estimates of the reference detector values, and not to corresponding errors in the image operators, as the primary factor responsible for instability of absolute measures. The significance of these findings for practical imaging studies of tissue is discussed.

[An AFLP marker related to fibrogenesis in upland cotton (Gossypium hirsuturm L.)]

By using AFLP technique polymorphism analysis was performed between a fuzzlesslintless mutant line and its isogenic wild-type line, Xuzhou 142. Out of 6,360 bands produced by 64 pairs primers, a fragment, named as CF1, appearing stably in wild-type line, Xuzhou 142. This polymorphism was further verified using several normal fiber varieties and F2, F3 populations from the cross of fuzzless-lintless mutant line with a high-lint-percentage variety Yumian No. 1. The cosegregation of CF1 and fibrogenesis was proved, which suggested that CF1 can be used as a molecular marker for cotton fibrogenesis. The CF1 segment was cloned into PUCm-T Vector and then sequenced. The putative amino acid sequences, is an analogue to phenol hydroxylase alpha subunit, outer surface protein C, NADH dehydrogenase subunit 1, NADH-ubiquinone oxidoreductase, 2-oxoacid ferredoxin oxidoreduct and hypothetical 14.5kD protein.

The length, phosphorylation state, and primary structure of the RNA polymerase II carboxyl-terminal domain dictate interactions with mRNA capping enzymes

The carboxyl-terminal domain (CTD) of elongating RNA polymerase II serves as a landing pad for macromolecular assemblies that regulate mRNA synthesis and processing. The capping apparatus is the first of the assemblies to act on the nascent pre-mRNA and the one for which binding of the catalytic components is most clearly dependent on CTD phosphorylation. The present study highlights a distinctive strategy of cap targeting in fission yeast whereby the triphosphatase (Pct1) and guanylyltransferase (Pce1) enzymes of the capping apparatus do not interact physically with each other (as they do in budding yeast and metazoans), but instead bind independently to the phosphorylated CTD. In vivo interactions of Pct1 and Pce1 with the CTD in a two-hybrid assay require 12 and 14 tandem repeats of the CTD heptapeptide, respectively. Pct1 and Pce1 bind in vitro to synthetic CTD peptides containing phosphoserine uniquely at position 5 or doubly at positions 2 and 5 of each of four tandem YSPTSPS repeats, but they bind weakly (Pce1) or not at all (Pct1) to a peptide containing phosphoserine at position 2. These results illustrate how remodeling of the CTD phosphorylation array might influence the recruitment and dissociation of the capping enzymes during elongation. But how does the CTD structure itself dictate interactions with the RNA processing enzymes independent of the phosphorylation state? Using CTD-Ser5 phosphopeptides containing alanine substitutions at other positions of the heptad, we define essential roles for Tyr-1 and Pro-3 (but not Thr-4 or Pro-6) in the binding of Schizosaccharomyces pombe guanylyltransferase. Tyr-1 is also essential for binding and allosteric activation of mammalian guanylyltransferase by CTD Ser5-PO4, whereas alanine mutations of Pro-3 and Pro-6 reduce the affinity for the allosteric CTD-binding site. These are the first structure-activity relationships deduced for an effector function of the phosphorylated CTD.

Normalized-constraint algorithm for minimizing inter-parameter crosstalk in DC optical tomography

In this report, we present a method for reducing the inter-coefficient crosstalk problem in optical tomography. The method described is an extension of a previously reported normalized difference method that evaluates relative detector values, and employs a weight matrix scaling technique together with a constrained CGD method for image reconstruction. Results from numerical and experimental studies using DC measurement data demonstrate that the approach can effectively isolate absorption and scattering heterogeneities, even for complex combinations of perturbations in optical properties. The significance of these results in light of recent theoretical findings is discussed.

[The cloning of apple ferritin gene (Apfl) from Malus xiaojinensis Cheng et Jiang and its structure analysis]

The special primers were designed based on the sequence information of plant ferritin genes reported in the literature and used for polymerase chain reaction (PCR) with the genomic DNA of Malus xiaojinensis Cheng et Jiang in an attempt to clone apple ferritin gene. A single fragment of 771 bp was successfully obtained from the PCRs and cloned in this study. The sequence and homology analysis results of the fragment showed that the deduced amino acids of the fragment had a ninety-nine percent homology to that of the soybean ferritin gene reported by Lescure et al. (1991). A comparison in details of the nucleotide sequence of the clone and that of the soybean ferritin gene showed that they consisted of the same open reading frame (ORF, 753 bp) and that the cloned fragment had complete initial and stop codes. Within the ORF no introns were found and there were no nucleotide difference in the transit peptide region (TP) of the gene, but five nucleotide mutations were found in the mature peptide region (MP), among which four were synonymous mutations.

PEGylated PLGA nanoparticles as protein carriers: synthesis, preparation and biodistribution in rats

The aim of the present work was to assess the merits of PEGylated poly(lactic-co-glycolic acid) (PEG-PLGA) nanoparticles as protein and peptide drugs (PPD) carriers. PEG-PLGA copolymer, which could be used to prepare the stealth nanoparticles or long-circulating nanoparticles, was synthesized with methoxypolyethyleneglycol (MePEG) and PLGA. The structure of PEG-PLGA was confirmed with (1)H NMR and Fourier transform infrared (FTIR) spectrum, and molecular weight was determined by gel permeation chromatography (GPC). Bovine serum albumin (BSA), chosen as model protein, was encapsulated within the stealth nanoparticles with the double emulsion method. The particles were characterized in terms of size, zeta potential and in vitro release of the protein. The biological fate of the BSA-loaded nanoparticles following intravenous administration was determined over 24 h in rats. The experimental results showed that PEG-PLGA could be obtained by ring-opening polymerization of lactide and glycolide in the presence of MePEG. (1)H NMR and FTIR spectrum were consistent with the structure of PEG-PLGA copolymer. Molecular weight determined by GPC was 50800. The stealth nanoparticles loading BSA could be prepared by the double emulsion technique. The entrapment efficiency was 48.6%, particle size about 200 nm and zeta potential -16.1 mV. BSA release from the stealth nanoparticles showed an initial burst release and then sustained release. PEG-PLGA nanoparticles could extend half-life of BSA from 13.6 min of loaded in PLGA nanoparticles to 4.5 h and obviously change the protein biodistribution in rats compared with that of PLGA nanoparticles. Thus, PEG-PLGA nanoparticles could be an effective carrier for PPD delivery.

A "two-hit" model of cystogenesis in autosomal dominant polycystic kidney disease?

An intriguing feature of autosomal dominant polycystic kidney disease (ADPKD) is the focal and sporadic nature of individual cyst formation. Typically, only a few renal cysts are detectable in an affected individual during the first two decades of life. By the fifth decade, however, hundreds to thousands of renal cysts can be found in most patients. Additionally, significant intra-familial variability of ADPKD has been well documented. Taken together, these findings suggest that factor(s) in addition to the germline mutation of a polycystic kidney disease gene might be required for individual cyst formation. Indeed, recent studies have provided compelling evidence in support of a "two-hit" model of cystogenesis in ADPKD. In this model, inactivation of both copies of a polycystic kidney disease gene by germline and somatic mutations within an epithelial cell provides growth advantages for it to proliferate clonally into a cyst. This article highlights key findings of these recent studies and discusses the controversies and implications of the "two-hit" model in ADPKD.

[AFLP markers of restoring genes of the wild-abortive hybrid rice]

Fertile and sterile pools were set up by bulked segregant analysis (BSA) based on the selection for the highly fertile and highly sterile plants of Shanyou 63 F2 population. The AFLP analysis of the two pools indicated that 64 primer combinations amplified 3,477 stable and clear bands. Exception of the combination E-AGC/M-CAA, all primer combinations had not detected polymorphism between the two pools. It was proved by investigation of two parents, individuals of F2 segregant population, backbone sterile lines and restorer lines that the polymorphic fragment AP1 generated from the primer E-AGC/M-CAA was associated with the restoring gene. AP1 was a single copy detected by Southern blot hybridization. The distance between AP1 and the restoring gene was 4.76 cM.

Bilineal disease and trans-heterozygotes in autosomal dominant polycystic kidney disease

In searching for a putative third gene for autosomal dominant polycystic kidney disease (ADPKD), we studied the genetic inheritance of a large family (NFL10) previously excluded from linkage to both the PKD1 locus and the PKD2 locus. We screened 48 members of the NFL10 pedigree, by ultrasonography, and genotyped them, with informative markers, at both the PKD1 locus and the PKD2 locus. Twenty-eight of 48 individuals assessed were affected with ADPKD. Inspection of the haplotypes of these individuals suggested the possibility of bilineal disease from independently segregating PKD1 and PKD2 mutations. Using single-stranded conformational analysis, we screened for and found a PKD2 mutation (i.e., 2152delA; L736X) in 12 affected pedigree members. Additionally, when the disease status of these individuals was coded as "unknown" in linkage analysis, we also found, with markers at the PKD1 locus, significant LOD scores (i.e., >3.0). These findings strongly support the presence of a PKD1 mutation in 15 other affected pedigree members, who lack the PKD2 mutation. Two additional affected individuals had trans-heterozygous mutations involving both genes, and they had renal disease that was more severe than that in affected individuals who had either mutation alone. This is the first documentation of bilineal disease in ADPKD. In humans, trans-heterozygous mutations involving both PKD1 and PKD2 are not necessarily embryonically lethal. However, the disease associated with the presence of both mutations appears to be more severe than the disease associated with either mutation alone. The presence of bilineal disease as a confounder needs to be considered seriously in the search for the elusive PKD3 locus.

Characterization of Schizosaccharomyces pombe RNA triphosphatase

RNA triphosphatase catalyzes the first step in mRNA cap formation which entails the cleavage of the beta-gamma phosphoanhydride bond of triphosphate-terminated RNA to yield a diphosphate end that is then capped with GMP by RNA guanylyltransferase. Here we characterize a 303 amino acid RNA triphosphatase (Pct1p) encoded by the fission yeast SCHIZOSACCHAROMYCES: pombe. Pct1p hydrolyzes the gamma phosphate of triphosphate-terminated poly(A) in the presence of magnesium. Pct1p also hydrolyzes ATP to ADP and P(i) in the presence of manganese or cobalt (K(m) = 19 microM ATP; k(cat) = 67 s(-1)). Hydrolysis of 1 mM ATP is inhibited with increasing potency by inorganic phosphate (I(0.5) = 1 mM), pyrophosphate (I(0.5) = 0.4 mM) and tripolyphosphate (I(0.5) = 30 microM). Velocity sedimentation indicates that Pct1p is a homodimer. Pct1p is biochemically and structurally similar to the catalytic domain of Saccharomyces cerevisiae RNA triphosphatase Cet1p. Mechanistic conservation between Pct1p and Cet1p is underscored by a mutational analysis of the putative metal-binding site of Pct1p. Pct1p is functional in vivo in S.cerevisiae in lieu of Cet1p, provided that it is coexpressed with the S.pombe guanylyltransferase. Pct1p and other yeast RNA triphosphatases are completely unrelated, mechanistically and structurally, to the metazoan RNA triphosphatases, suggesting an abrupt evolutionary divergence of the capping apparatus during the transition from fungal to metazoan species.

[T cell and molecule-1 detection in cornea of fetus, neonates, children and adults]

OBJECTIVE

To study the immune state of human cornea with different ages.

METHODS

The human corneas in different ages were detected by using immunohistochemical techniques for 5 types of monoclonal antibody.

RESULTS

The contents of T-cell (CD(+)(3)), helper/inducer (CD(+)(4)), toxic T-cell (CD(+)(8)), macrophage (CD(+)(68)) and molecule-1 (intercellular adhesive molecule, CD(+)(54)) in the adult cornea were relatively low, mainly in the limbus but none at the corneal center. These positive cells were less in corneas of fetus, neonates and children than that in adults.

CONCLUSION

In corneas of fetus, neonates and children, the T-cell, macrophage and molecule-1 were less than that of adults. Their corneas may be used as donors in corneal transplantation.

Instrumentation and calibration protocol for imaging dynamic features in dense-scattering media by optical tomography

Instrumentation is described that is suitable for acquiring multisource, multidetector, time-series optical data at high sampling rates (up to 150 Hz) from tissues having arbitrary geometries. The design rationale, calibration protocol, and measured performance features are given for both a currently used, CCD-camera-based instrument and a new silicon-photodiode-based system under construction. Also shown are representative images that we reconstructed from data acquired in laboratory studies using the described CCD-based instrument.

Evidence for involvement of the epidermal platelet-activating factor receptor in ultraviolet-B-radiation-induced interleukin-8 production

Ultraviolet B radiation has been shown to generate cutaneous inflammation in part through inducing oxidative stress and cytokine production in human keratinocytes. Amongst the proinflammatory cytokines synthesized in response to ultraviolet B radiation is the potent chemoattractant interleukin-8. Though the lipid mediator platelet-activating factor (PAF) is synthesized in response to oxidative stress, and keratinocytes express PAF receptors linked to cytokine biosynthesis, it is not known whether PAF is involved in ultraviolet-B-induced epidermal cell cytokine production. These studies examined the role of the PAF system in ultraviolet-B-induced epidermal cell interleukin-8 biosynthesis using a novel model system created by retroviral-mediated transduction of the PAF-receptor-negative human epidermal cell line KB with the human PAF receptor. Treatment of PAF-receptor-expressing KB cells with the metabolically stable PAF receptor agonist carbamoyl-PAF resulted in increased interleukin-8 mRNA and protein, indicating that activation of the epidermal PAF receptor was linked to interleukin-8 production. Ultraviolet B irradiation of PAF-receptor-expressing KB cells resulted in significant increases in both interleukin-8 mRNA and protein in comparison to ultraviolet-B-treated control KB cells. Pretreatment with PAF receptor antagonists inhibited both carbamoyl-PAF-induced and ultraviolet-B-induced interleukin-8 production in the PAF-receptor-positive cells, but not in control KB cells. Similarly, treatment of the PAF-receptor-expressing primary cultures of human keratinocytes or the human epidermal cell line A-431 with carbamoyl-PAF or ultraviolet B radiation resulted in interleukin-8 production that was partially inhibited by PAF receptor antagonists. These studies suggest that the epidermal PAF receptor may be a pharmacologic target for ultraviolet B radiation in skin and thus may act to augment ultraviolet-B-mediated production of cytokines such as interleukin-8.

Use of enhanced green fluorescent protein to monitor retroviral-mediated gene therapy in human keratinocytes

Keratinocytes have great promise as targets for gene therapy involving both skin as well as for systemic disorders due to their availability and potential long life span. Improvement of gene transfer into keratinocytes will be greatly facilitated by markers that will allow both rapid detection and efficient selection of transduced cells. For these purposes, a recombinant version of the Aequorea victoria green fluorescent protein that is enhanced for high-level expression in mammalian cells (EGFP) was placed into a replication-deficient retroviral vector. High-titer retrovirus was used to transduce both primary cultures of neonatal foreskin-derived human keratinocytes (HK) as well as the immortalized keratinocyte-derived cell line HaCaT. Both cell types stably expressed the EGFP, and this marker allowed rapid purification of transduced cells by fluorescence-activated cell sorting. EGFP expression was seen in HaCaT keratinocytes for at least 40 passages, and the presence of this construct did not effect cell growth, or apoptosis in response to UVB or etoposide. Transduced populations of HK were grafted into SCID mice, resulting in a functional epidermis. EGFP expression was readily seen in vivo by exposing the xenografts to an ultraviolet light source. These studies demonstrate the feasibility of using EGFP as a convenient and rapid marker to monitor keratinocyte gene transfer both in vitro and in vivo.

Primary structure of the sialodacryoadenitis virus genome: sequence of the structural-protein region and its application for differential diagnosis

Sialodacryoadenitis virus (SDAV) is a coronavirus that is commonly found in laboratory rats and that causes sialodacryoadenitis and respiratory illness. We cloned and sequenced the 3' terminal 9.8 kb of the genomic RNA and analyzed the structure of the viral genome. As with mouse hepatitis coronaviruses (MHVs), the SDAV genome was able to code for a spike protein, a small membrane protein, a membrane-associated protein, and a nucleocapsid protein. In addition, the hemagglutinin-esterase gene capable of encoding a protein of 439 amino acids (aa) was identified. The putative functional site for acetylesterase activity was present in the HE protein as Phe-Gly-Asp-Ser (FGDS), suggesting that the SDAV HE protein might have retained the esterase activity. Immediately upstream of the HE gene and downstream of the polymerase 1b gene, the NS2 nonstructural-protein gene was identified with a coding capacity of 274 aa. A motif of UCUAAAC was identified as a potential transcription signal for subgenomic mRNA synthesis. Large insertions of 172, 127, and 44 aa were detected in the N-terminal half of the predicted S protein of SDAV when its sequence was compared to the sequences of MHV 2, MHV JHM, and MHV A59, respectively. The sequence information on the SDAV S-protein gene was applied to a differential diagnostic PCR to detect and distinguish the rat coronavirus from mouse coronaviruses. This is the first report on the comprehensive genetic information of any rat coronavirus.

[Purification and characterization of cuticle-degrading protease from entomopathogenic fungus, Metarhizium anisopliae]

The cuticle-degrading proteases from entomopathogensis fungus, Melarhizium anisopliae, were induced by adding cicada exuviae, colloidal chitin, shrimp cuticle, maggot cuticle, horsefly cuticle and silkworm chrysalis cuticle into minimal medium. After ultrafiltration, Ultrogel AcA 54 column and IEF, a protease designated as MAP-21 with Mr 27 kD, and pI 7.6 were purified. It was shown that the recognition site of MAP-21 was Arg, PMSF and TLCK could inhibited the activity of this protease, indicating that there were Ser and His residues in the active center. The inhibitors to trypsin, leupeptin antipain and STI also repressed the activity of MAP-21, while chymostatin, TPCK and elastatinal TEI were shown no inhibition to its activity, demonstrating that, MAP-21 was a trypsin-like protease. Other properties of MAP-21 were also reported.

Mutations of PKD1 in ADPKD2 cysts suggest a pathogenic effect of trans-heterozygous mutations

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 and PKD2. The products of these genes associate to form heteromeric complexes. Several models have been proposed to explain the mechanism of cyst formation. Here we find somatic mutations of PKD2 in 71% of ADPKD2 cysts analysed. Clonal somatic mutations of PKD1 were identified in a subset of cysts that lacked PKD2 mutations.

Characterization of Candida albicans RNA triphosphatase and mutational analysis of its active site

The RNA triphosphatase component (CaCet1p) of the mRNA capping apparatus of the pathogenic fungus Candida albicans differs mechanistically and structurally from the RNA triphosphatase of mammals. Hence, CaCet1p is an attractive antifungal target. Here we identify a C-terminal catalytic domain of CaCet1p from residue 257 to 520 and characterize a manganese-dependent and cobalt-dependent NTPase activity intrinsic to CaCet1p. The NTPase can be exploited to screen in vitro for inhibitors. The amino acids that comprise the active site of CaCet1p were identified by alanine-scanning mutagenesis, which was guided by the crystal structure of the homologous RNA triphosphatase from Saccharomyces cerevisiae (Cet1p). Thirteen residues required for the phosphohydrolase activity of CaCet1p (Glu287, Glu289, Asp363, Arg379, Lys396, Glu420, Arg441, Lys443, Arg445, Asp458, Glu472, Glu474 and Glu476) are located within the hydrophilic interior of an eight-strand beta barrel of Cet1p. Each of the eight strands contributes at least one essential amino acid. The essential CaCet1p residues include all of the side chains that coordinate manganese and sulfate (i.e., gamma phosphate) in the Cet1p product complex. These results suggest that the active site structure and catalytic mechanism are conserved among fungal RNA triphosphatases.

Association between angiotensin-converting enzyme and Alzheimer disease

BACKGROUND

Angiotensin-converting enzyme has been reported to show altered activity in patients with neurologic diseases. An insertion-deletion polymorphism in ACE has recently been linked to heart disease, cerebrovascular disease, and AD.

OBJECTIVE

To determine whether the angiotensin-converting enzyme (ACE) is associated with risk of Alzheimer disease (AD).

METHODS

We investigated the ACE polymorphism as a potential risk factor for AD in 151 patients with AD and 206 ethnically matched controls from Russia and in 236 patients with AD and 169 controls from North America by means of allele association methods and logistic regression.

RESULTS

None of the ACE genotypes was associated with increased susceptibility to AD in the total sample or in subsets stratified by apolipoprotein E gene (APOE) epsilon4 status. However, the D allele was more frequent among AD cases between ages 66 and 70 years compared with controls in both the Russian (P = .02) and North American (P = .001) datasets. In this age group, the effect of D (odds ratio, 11.2; 95% confidence interval, 2.9-44.0) appeared to be independent of and equal or greater in magnitude to the effect of APOE epsilon4 (odds ratio, 7.8; 95% confidence interval, 3.5-7.4).

CONCLUSIONS

Our results suggest that APOE and ACE genotypes may be independent risk factors for late-onset AD, but the ACE association needs to be confirmed in independent samples in which the time and extent of vascular cofactors can be assessed.

Modeling of sensitivity and resolution to an included object in homogeneous scattering media and in MRI-derived breast maps

We have examined the measured sensitivity and edge resolution to an included tumor in MR-derived maps of the breast exposed to NIR illumination. A large parameter space was explored, enabling a systematic examination of the influence that measurement parameters (e.g., view angle, source position, wavelength) and target medium parameters (e.g., breast and tumor size, background tissue properties, and tumor contrast) have on the computed responses. The significance of these finding on data collection schemes for imaging studies is discussed.

Mutational analyses of yeast RNA triphosphatases highlight a common mechanism of metal-dependent NTP hydrolysis and a means of targeting enzymes to pre-mRNAs in vivo by fusion to the guanylyltransferase component of the capping apparatus

Saccharomyces cerevisiae Cet1p is the prototype of a family of metal-dependent RNA 5'-triphosphatases/NTPases encoded by fungi and DNA viruses; the family is defined by conserved sequence motifs A, B, and C. We tested the effects of 12 alanine substitutions and 16 conservative modifications at 18 positions of the motifs. Eight residues were identified as important for triphosphatase activity. These were Glu-305, Glu-307, and Phe-310 in motif A (IELEMKF); Arg-454 and Lys-456 in motif B (RTK); Glu-492, Glu-494, and Glu-496 in motif C (EVELE). Four acidic residues, Glu-305, Glu-307, Glu-494, and Glu-496, may comprise the metal-binding site(s), insofar as their replacement by glutamine inactivated Cet1p. E492Q retained triphosphatase activity. Basic residues Arg-454 and Lys-456 in motif B are implicated in binding to the 5'-triphosphate. Changing Arg-454 to alanine or glutamine resulted in a 30-fold increase in the K(m) for ATP, whereas substitution with lysine increased K(m) 6-fold. Changing Lys-456 to alanine or glutamine increased K(m) an order of magnitude; ATP binding was restored when arginine was introduced. Alanine in lieu of Phe-310 inactivated Cet1p, whereas Tyr or Leu restored function. Alanine mutations at aliphatic residues Leu-306, Val-493, and Leu-495 resulted in thermal instability in vivo and in vitro. A second S. cerevisiae RNA triphosphatase/NTPase (named Cth1p) containing motifs A, B, and C was identified and characterized. Cth1p activity was abolished by E87A and E89A mutations in motif A. Cth1p is nonessential for yeast growth and, by itself, cannot fulfill the essential role played by Cet1p in vivo. Yet, fusion of Cth1p in cis to the guanylyltransferase domain of mammalian capping enzyme allowed Cth1p to complement growth of cet1Delta yeast cells. This finding illustrates that mammalian guanylyltransferase can be used as a vehicle to deliver enzymes to nascent pre-mRNAs in vivo, most likely through its binding to the phosphorylated CTD of RNA polymerase II.

Screening plasma aluminum levels in relation to aluminum bone disease among asymptomatic dialysis patients

Aluminum accumulation in plasma and tissues is a well-described complication among persons undergoing peritoneal dialysis or hemodialysis. Excess bone aluminum is associated with low bone formation rates and increased risk for fractures. Current recommendations for care of patients with end-stage renal disease include screening for aluminum toxicity with plasma aluminum levels; patients with levels below 40 microg/L are considered to be at low risk for aluminum bone disease (ABD). We examined data from the Toronto Renal Osteodystrophy Study to evaluate the performance of plasma aluminum levels in screening for ABD. Two hundred fifty-eight unselected patients undergoing peritoneal dialysis (n = 143) or hemodialysis (n = 115) underwent diagnostic bone biopsy and measurement of plasma aluminum level. Sixty-nine patients (26.7%) were identified as having ABD, defined as low or normal bone formation rates with 25% or more bone surface aluminum staining. Plasma aluminum level was strongly associated with the presence of ABD; the odds ratio was 1.4 for each increase of 10 microg/L (95%CI, 1.2, 1.6). However, only 50.1% of patients with a plasma aluminum level of 40 microg/L or greater had ABD, whereas 14.2% of patients with a level below this threshold also had ABD. Using this cutoff level of 40 microg/L, the sensitivity and specificity were 65.2% and 76.7%, respectively. We conclude that although there is a correlation between high aluminum levels and ABD, a patient's plasma aluminum level does not predict well the presence of ABD in spite of a relatively high prevalence of disease.

Augmentation of ultraviolet B radiation-induced tumor necrosis factor production by the epidermal platelet-activating factor receptor

Ultraviolet B radiation (UVB) has been shown to damage human keratinocytes in part by inducing oxidative stress and cytokine production. Indeed, UVB-induced production of the pro-inflammatory and cytotoxic cytokine tumor necrosis factor alpha (TNF-alpha) has been implicated in the epidermal damage seen in response to acute solar radiation. Though the lipid mediator platelet-activating factor (PAF) is synthesized in response to oxidative stress, and keratinocytes express PAF receptors linked to cytokine biosynthesis, it is not known whether PAF is involved in UVB-induced epidermal cell cytokine production. These studies examined the role of the PAF system in UVB-induced epidermal cell TNF-alpha biosynthesis using a novel model system created by retroviral-mediated transduction of the PAF receptor-negative human epidermal cell line KB with the human PAF receptor (PAF-R). Treatment of PAF-R-expressing KB cells with the metabolically stable PAF-R agonist carbamoyl-PAF resulted in increased TNF-alpha mRNA and protein, indicating that activation of the epidermal PAF-R was linked to TNF-alpha production. UVB irradiation of PAF-R-expressing KB cells resulted in significant increases in both TNF-alpha mRNA and protein in comparison to UVB-treated control KB cells. However, UVB treatment up-regulated cyclooxygenase-2 mRNA levels to the same extent in both PAF-R-expressing and control KB cells. Pretreatment with the antioxidant vitamin E or the PAF-R antagonists WEB 2086 and A-85783 inhibited UVB-induced TNF-alpha production in the PAF-R-positive but not control KB cells. These studies suggest that the epidermal PAF-R may be a pharmacological target for UVB in skin.

[Purification and characterization of a novel antifungal peptide APS-1 produced by Bacillus cereus]

In previous study, we isolated an antagonist Bacillus cereus strain: S-1 from cotton plant. In field experiments, this bacterium was shown strong inhibition to several plant diseases. In this paper, we reported the purification of the antifungal substance produced by the bacterium and its properties. After the steps of acid precipitation, methanol and ethy lether extraction, Sephadex G100 and DEAE52 column chromatography, the antifungal material was purified. The purified material had absorption peak at 275 nm, and was exhibited negative in biuret color reaction. However after hydrolyzed with HCl, this substance shown positive in the same reaction. Amino acid analysis to the hydrolysate of APS-1 showed that APS-1 was composed of Glu, Asp, Tyr, Ser, Thr, Pro, Leu, Ile, Val and an unknown amino acid. Combining with its pratial resistance to proteinases, it was suggested that this antifungal material was a cyclic peptide. This peptide, named APS-1, with strong inhibition on the germination of spores of the phytopathogens tested, was shown high stability against ultraviolet radiation and heat. APS-1 may have potential role in plant diseases biological control.