Identification of site(s) of insulin nitration by peroxynitrite and characterization of its structural change

Insulin nitration mediated by peroxynitrite (ONOO(-)) has been implicated in diabetes and diabetic cardiovascular complications. In this study, we identified the nitration sites of porcine insulin by infusion of ONOO(-) and quantified its secondary structural change. Insulin was cleaved with V8 protease to six peptides (four of them contained each tyrosine residue), then analyzed by HPLC-MS and further confirmed the nitration sites by HPLC-MS/MS. At low accumulated doses of peroxynitrite, the main products were two different mono-nitrated insulin species at Tyr-A19 and Tyr-B26 with Tyr-A19 being predominant as shown by peptide mapping. Also, the content of alpha-helix structure of insulin reduced to 22.9 % and random-coil structure increased to 30.2 % (compare with native insulin of 41.7 % and 13.7 %, respectively) as determined by FTIR spectra.

Efficient human growth hormone gene expression in the milk of non-transgenic goats

Heterogenous expression of recombinant proteins in milk of livestock at a large scale is very labour-intensive to be achieved with current transgenic animals, and usually seen as time-consuming, expensive and technically most challenging. Here we describe a convenient system for transient production of recombinant human growth hormone and its extensive use in recombinant protein production for therapeutic purposes. In this study, an adenoviral vector containing the GFP gene and hGH gene was constructed for direct infusion into the epithelium of mammary glands of goats via the teat canal during the period of natural lactation. Western-blot analysis of milk samples obtained from all of the viral-treated founders indicated that the recombinant hGH (rhGH) was secreted into the milk of the goats. The concentrations of rhGH in milk ranged from 0.6 to 2.4 mg/ml and lasted for more than 10 days during lactation. These data suggest that it is possible to produce larger amounts of recombinant human growth hormone in the milk of livestock animals by using replication-defective adenoviruses.

Operational characteristics of continuous renal replacement modalities used for critically ill patients with acute kidney injury

Renal replacement therapy (RRT) is required in a significant percentage of patients developing acute kidney injury (AKI) in an intensive care unit (ICU) setting. One of the foremost objectives of continuous renal replacement therapy (CRRT) is the removal of excess fluid and blood solutes that are retained as a consequence of decreased or absent glomerular filtration. Because prescription of CRRT requires goals to be set with regard to the rate and extent of both solute and fluid removal, a thorough understanding of the mechanisms by which solute and fluid removal occurs during CRRT is necessary. The following provides an overview of solute and water transfer during CRRT and this information is placed in the appropriate clinical context with a discussion of recent clinical trials assessing the relationship between CRRT dose and patient survival. Moreover, the differences between solute removal in CRRT and other dialysis modalities, especially sustained low-efficiency dialysis (SLED) and extended daily dialysis (EDD), along with the potential clinical implications are discussed.

Measurement of the elastic constants of a columnar SiC thin film

The technique of resonant ultrasound spectroscopy was used to measure the elastic properties of a polycrystalline cubic silicon carbide (3C-SiC) thin film. The film, grown on a silicon (100) substrate, was 1.69 microns thick with columnar crystalline grains and a (111) texture. The substrate with the film was placed between two transducers and the resonant frequencies were measured; measurements were repeated after selective, timed dry etching of the film, allowing a determination of the elastic constants of the film alone. The film elastic constants, c(11)=371 and c(12)=146 GPa, were within a few percent of the literature values (c(11)=386, c(12)=136 GPa) of crystalline 3C-SiC. However, the film elastic constant c(44), 111 GPa, was significantly smaller than the bulk literature value, 254 GPa. For the film, c44 approximately (c(11)-c(12))/2, indicating that, quite unlike a bulk 3C-SiC crystal, the thin film is elastically isotropic.

Population dynamics and maturation cycle of Camallanus cotti (Nematoda: Camallanidae) in the Chinese hooksnout carp Opsariichthys bidens (Osteichthyes: Cyprinidae) from a reservoir in China

The seasonal population dynamics and maturation cycle of the nematode Camallanus cotti in the posterior intestine of Chinese hooksnout carp Opsariichthys bidens have been studied in the Danjiangkou Reservoir of the Hubei Province in central China from September 2004 to November 2005. The overall prevalence, mean abundance and intensity of C. cotti among fish sampled (n=700 fish) were 47%, 2.29+/-12.38 (+/-S.D.) and 1-307 (average 4.89+/-17.74), respectively. The overall sexual ratio of female to male nematodes (excluding L3 and L4 juveniles) was 1.17:1. Statistical results showed weakly positive correlations between fish length and the number of nematodes per host. The dynamics of infection of the nematode exhibited significant seasonal pattern in changes in mean abundance. A similar pattern was found for changes in nematode prevalence, although this was not statistically significant. Higher levels of infection were observed among fish sampled in summer months and the lower in the winter. Neither the prevalence nor the abundance of the parasite was significantly different between male and female hosts. The pattern of frequency distribution of the parasite in the host was found to be over-dispersed throughout the sampling period. In addition, studies on the development and maturation of the parasite in O. bidens revealed that development (maturation), recruitment of the next generation, and reproduction may be continuous year-round, although reproduction may peak during the winter.

Expression of the nucleoprotein gene of rabies virus for use as a diagnostic reagent

The nucleoprotein (N) gene of rabies virus CTN strain, was cloned, sequenced and expressed in Escherichia coli as a fusion with maltose binding protein (MBP). The antigenicity of this recombinant MBP-N fusion protein was examined by Western blotting and enzyme linked immunosorbent assay (ELISA). Subsequently, an indirect ELISA was developed to detect rabies specific antibody levels. Using sera from naive and vaccinated animals the ELISA results were compared with virus neutralizing antibodies detected by a rapid fluorescent focus inhibition test (RFFIT). Neutralizing titres by RFFIT were found to correlate well with the OD values in the ELISA (r=0.9436) and the sensitivity and specificity of the ELISA were shown to be 93.4 and 100%, respectively. The data indicate that the recombinant MBP-N fusion protein can be expressed and isolated straightforwardly and may be useful as a safe and abundant source of antigen to monitor seropositivity in vaccinated canines.

IGF2 is critical for tumorigenesis by synovial sarcoma oncoprotein SYT-SSX1

Synovial sarcoma is an aggressive soft tissue tumor characterized by a specific chromosomal translocation between chromosome 18 and X. This translocation can generate a fusion transcript encoding SYT-SSX1, a transforming oncoprotein. We present evidence that SYT-SSX1 induces insulin-like growth factor II expression in fibroblast cells. SYT-SSX2, a fusion also frequently found in synovial sarcoma, is necessary for maintaining Igf2 expression in the synovial sarcoma cell line, and the increased IGF2 synthesis protects cells from anoikis and is required for tumor formation in vivo. We also found a loss of imprinting (LOI) for Igf2 in a limited number of primary synovial sarcomas despite demethylation of CpG dinucleotides critical for maintaining imprinting. These findings suggest that inhibition of the IGF2/IGF1-R signaling pathway may represent a significant therapeutic modality for treating synovial sarcoma.

Objective decomposition of the stress tensor in granular flows

A model for the stress tensor in granular flows [Volfson, Tsimring, and Aranson, Phys. Rev. Lett. 90, 254301 (2003)] is correctly generalized to an objective form that is independent of the coordinate system. The objective representation correctly models the isotropic and anisotropic parts of the stress tensor, whereas the original model for stress tensor components is dependent on the coordinate system. This general objective form of the model also relaxes the assumption in the original model that the principal axes of the granular stress tensor be coaxial with that of the "fluid" stress tensor. This generalization expands the applicability of the model to a wider class of granular flows. The objective representation is also useful in analyzing other models based on additive decomposition of the stress tensor in granular flows.

CD40 antisense oligonucleotide inhibition of trinitrobenzene sulphonic acid induced rat colitis

BACKGROUND

CD154/CD40 interactions play a pivotal role both in humoral and cellular immune responses. Their involvement in the pathogenesis of chronic inflammatory bowel disease (IBD) has been revealed by increased expression of CD40 and CD154 in the inflamed mucosa of patients and the therapeutic effects of anti-CD154 antibodies in experimental colitis. Because of adverse side effects however, the use of such antibodies in patients with IBD may be limited.

AIMS

An alternative approach to blocking CD154/CD40 interactions by employing a CD40 antisense oligonucleotide (ODN) was explored.

RESULTS

After sequencing of the rat CD40 gene, five antisense ODNs were designed, of which one (rAS3) effectively downregulated CD40 expression in rat vascular smooth muscle cells as well as the subsequent changes in gene expression in response to CD40 stimulation. The therapeutic potency of rAS3 was evaluated in the 2,4,6-trinitrobenzene sulphonic acid (TNBS) induced colitis model of the rat. Single intracolonic injection of a liposomal formulation of rAS3 either prior to or post colitis induction markedly suppressed the inflammatory reaction in these animals monitored both macroscopically and microscopically over one week, while application of a scrambled control ODN had no such effects. Moreover, reverse transcription-polymerase chain reaction analyses revealed reduced expression of vascular cell adhesion molecule 1, interleukin 12 p40, and monocyte chemoatractive protein 1 in the inflamed mucosa, which in turn may have contributed to the decrease in leucocyte infiltration judged by immunohistochemistry.

CONCLUSIONS

These results suggest that CD40 antisense ODNs effectively interfere with CD154/CD40 interactions in vivo and, therefore, may provide a novel approach to the treatment of patients with chronic IBD.

A new method for noninvasive measurement of multilayer tissue conductivity and structure using divided electrodes

This paper outlines a new method for measuring multilayer tissue conductivity and structure by using divided electrodes, in which current electrodes are divided into several parts. Our purpose is to estimate the multilayer tissue structure and the conductivity distribution in a cross section of the local tissue by using bioresistance data measured noninvasively. The effect of the new method is assessed by computer simulations using a typical two-dimensional (2-D) model. In this paper, the conductivity distribution in the model is analyzed based on a finite difference method (FDM) and a steepest descent method (SDM). Simulation results show that the conductivity values of skin, fat, and muscle layers can be estimated with an error of less than 0.1%. When random noise at various levels is added to the measured resistance values, estimates of the conductivity values for skin, fat, and muscle layers are still reasonably precise: their root mean square errors are about 1.06%, 1.39%, and 1.61% for 10% noise. In a 2-D model, increasing the number of divided electrodes permits simultaneous estimates of tissue structure and conductivity distribution. Optimal configuration for divided electrodes is examined in terms of dividing pattern.

Dynamic of lead speciation in sewage sludge composting

A large-scale sewage sludge composting experiment was conducted to develop an understanding of changes that occur to Pb chemical speciation, distribution and bio-availability during the course of composting. The four-stage Tessier sequential extraction method was employed to investigate the dynamics of heavy metal Pb speciation (exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and sulphides, residual) during the course of sewage sludge composting. The concentrations of the total Pb and the five Pb fractions concentrations were increased during the whole stage of compost. However, the percentages of Pb distribution with respect to total Pb were changed in the following manner: exchangeable, bound to Fe-Mn oxides and bound to carbonates Pb with respect to total Pb were increased, while the percentages of bound to organic matter and sulphides, and residual Pb with respect to total Pb were decreased during composting. The data showed that the quantity of Pb in the less toxic portion, such as consisting of organic matter and sulphides bound and residual Pb, was increased, and that the contamination and bio-availability of heavy metal Pb in sewage sludge was reduced during the composting process.

Television viewing and change in body fat from preschool to early adolescence: The Framingham Children's Study

OBJECTIVE

To prospectively examine the relation between television watching and body fat change in children from preschool to early adolescence.

METHODS

In a longitudinal study, 106 children were enrolled during preschool years (mean age 4.0 y) and followed into early adolescence (mean age 11.1 y). Parents completed an annual questionnaire on the child's television and video habits. Body mass index (BMI), triceps skinfolds, and sum of five skinfolds were recorded yearly at annual clinic visits. Longitudinal statistical analyses were carried out using mixed modeling procedures to control for potential confounding by a number of factors.

RESULTS

Television watching was an independent predictor of the change in the child's BMI, triceps, and sum of five skinfolds throughout childhood. Its effect was only slightly attenuated by controlling for the baseline body fat, level of physical activity (as measured repeatedly by Caltrac accelerometer), percent of calories from fat, total calorie intake, or the parents' BMI or education. By age 11, children who watched 3.0 h or more of television per day had a mean sum of skinfolds of 106.2 mm, compared with a mean sum of skinfolds of 76.5 mm for those who watched less than 1.75 h per day (P=0.007). Furthermore, the adverse effect of television viewing was worse for those children who were also sedentary or had a higher-fat diet.

CONCLUSIONS

Children who watched the most television during childhood had the greatest increase in body fat over time. Healthy lifestyle education designed to prevent obesity and its consequences should target television-watching habits of children.

Quantitative X-ray projection microscopy: phase-contrast and multi-spectral imaging

We outline a new approach to X-ray projection microscopy in a scanning electron microscope (SEM), which exploits phase contrast to boost the quality and information content of images. These developments have been made possible by the combination of a high-brightness field-emission gun (FEG)-based SEM, direct detection CCD technology and new phase retrieval algorithms. Using this approach we have been able to obtain spatial resolution of < 0.2 micro m and have demonstrated novel features such as: (i) phase-contrast enhanced visibility of high spatial frequency image features (e.g. edges and boundaries) over a wide energy range; (ii) energy-resolved imaging to simultaneously produce multiple quasi-monochromatic images using broad-band polychromatic illumination; (iii) easy implementation of microtomography; (iv) rapid and robust phase/amplitude-retrieval algorithms to enable new real-time and quantitative modes of microscopic imaging. These algorithms can also be applied successfully to recover object-plane information from intermediate-field images, unlocking the potentially greater contrast and resolution of the intermediate-field regime. Widespread applications are envisaged for fields such as materials science, biological and biomedical research and microelectronics device inspection. Some illustrative examples are presented. The quantitative methods described here are also very relevant to projection microscopy using other sources of radiation, such as visible light and electrons.

Lysophosphatidylcholine enhances superoxide anions production via endothelial NADH/NADPH oxidase

Reactive oxygen species (ROS) including superoxide anions (O2(-)) play a key role in atherogenesis, and endothelial cells have the ability to generate ROS. To investigate the enzymatic sources of ROS and the effects of lysophosphatidylcholine (LPC), an atherogenic lipid, we measured ROS production in cultured bovine aortic endothelial cells (BAECs) by the lucigenin-enhanced chemiluminescence (CL) method and electron spin resonance (ESR). BAEC homogenates had the enzymatic activity of NADH/NADPH oxidase. BAECs cultured on microcarrier beads generated O2(-) under basal conditions. The inhibition of NADH/ NADPH oxidase by diphenylene iodonium (DPI) significantly attenuated O2(-) production, whereas no inhibitors of other oxidases suppressed it. Although LPC enhanced O2(-) production approximately 3.1-fold, its action was suppressed by DPI. Tyrosine kinase inhibitors significantly attenuated LPC-induced O2(-) production. ESR with DMPO demonstrated that LPC increased the formation of the DMPO-hydroxyl adduct in dose- and time-dependent manners. These data suggest that the basal production of O2(-) in endothelial cells is mainly mediated by the NADH/NADPH oxidase system and that LPC activates this oxidase to enhance O2(-) production through a tyrosine kinase-dependent pathway. The enhancement of ROS production by LPC is probably involved in its atherogenic property.

Identification of the calcium-sensing receptor in the developing tooth organ

Calcium (Ca2+) is a critical component of tooth enamel, dentin, and the surrounding extracellular matrix. Ca2+ also may regulate tooth formation, although the mechanisms for such action are poorly understood. The Ca2+-sensing receptor (CaR) that is expressed in the parathyroid gland, kidney, bone, and cartilage has provided a mechanism by which extracellular Ca2+ can regulate cell function. Because these tissues play an important role in maintaining mineral homeostasis and because Ca2+ is hypothesized to play a crucial role in tooth formation, we determined whether the CaR was present in teeth. In this study, using immunohistochemistry, CaR protein was detected in developing porcine molars localized in the predentin (pD), early secretory-stage ameloblasts, maturation-stage smooth-ended ameloblasts (SA), and certain cells in the stratum intermedium. CaR protein and messenger RNA (mRNA) were detected also in an immortalized ameloblast-like cell line (PABSo-E) using immunofluorescence, reverse-transcription polymerase chain reaction (RT-PCR), and Northern analysis. Based on the observation that the CaR is expressed in cultured ameloblasts, we determined whether increments in medium Ca2+ concentration could activate the intracellular Ca2+ signal transduction pathway. In PABSo-E cells, increasing extracellular Ca2+ in the medium from 0 (baseline) to 2.5mM or 5.0 mM resulted in an increase in intracellular Ca2+ above baseline to 534 +/- 69 nM and 838 +/- 86 nM, respectively. Taken together, these results suggest that the CaR is expressed in developing teeth and may provide a mechanism by which these cells can respond to alterations in extracellular Ca2+ to regulate cell function and, ultimately, tooth formation.

[Weak signal detection in every heart cycle]

In this article, a new approach is introduced to lowering the myo-electronic noise in weak ECG signals. We use artificial neural network to make the noise be white, and then we adopt an adaptive filter of which the reference signal is achieved by extracting from other ECG cycle. The outcome is the reduction of both white noise and non-white noise in ECG signal. Satisfactory results have been achieved by using this method in the experiment of late potential detection.

Risk factors for intermediate-term survival after coronary artery bypass grafting

BACKGROUND

Risk factors for short-term mortality after coronary artery bypass grafting are well established, but little is known about risk factors for intermediate-term mortality.

METHODS

We analyzed the outcomes of 11,815 patients undergoing coronary artery bypass grafting in one of the 43 cardiac surgery programs of the Department of Veteran Affairs. Risk factors for intermediate- and short-term mortality were determined using Cox proportional hazards regression models. Effects of risk factors during these two periods were explicitly compared.

RESULTS

We found important differences in mortality risk-factor sets between the intermediate- and short-term periods after coronary artery bypass grafting. The majority of predictors of intermediate-term mortality were noncardiac-related variables, whereas the majority of predictors of short-term mortality were cardiac-related variables. Impaired functional status, chronic obstructive pulmonary disease, and renal dysfunction had greater effects in the intermediate-term period. Previous heart operation, angina class III or IV, previous myocardial infarction, and preoperative use of an intraaortic balloon pump had greater effects in the short-term period.

CONCLUSIONS

The risk factors for intermediate-term mortality identified in this study can augment preoperative risk assessment and counseling of patients. Clinicians should be aware of the importance of noncardiac-related variables as predictors of mortality in the intermediate-term period after coronary artery bypass grafting.