Essential roles of basic helix-loop-helix transcription factors, Capsulin and Musculin, during craniofacial myogenesis of zebrafish

Capsulin and Musculin are basic helix-loop-helix transcription factors, but their biophysiological roles in zebrafish cranial myogenesis are unclear. Expressions of endogenous capsulin transcripts are detected at the central- (~24-hpf) and at dorsal- and ventral-mesoderm cores (~30-72 hpf) of branchial arches. In contrast, musculin transcripts are expressed as a two-phase manner: early phase (20-22 hpf) expressions of musculin are detected at the head mesoderm, whereas late-phase (36-72 hpf) are detected at all presumptive head-muscle precursors. Knockdown of either capsulin or musculin leads to loss of all cranial muscles without affecting trunk muscle development. The defective phenotypes of Capsulin- and Musculin-morphant can be rescued by co-injection of mRNA of each other. Both myf5 and myod transcripts are down-regulated in the Capsulin-morphant while myod transcripts are up-regulated in the Musculin-morphant. Therefore, we propose a putative regulatory network to understand how capsulin/musculin regulate distinctly either myf5 or myod during zebrafish craniofacial myogenesis.

Nitrite-mediated S-nitrosylation of caspase-3 prevents hypoxia-induced endothelial barrier dysfunction

RATIONALE

Hypoxia is a significant perturbation that exacerbates endothelial barrier dysfunction, contributing to the disruption of vascular homeostasis and the development of various diseases such as atherosclerosis and metastasis of tumors. To date, it is not known what strategy might be used to counter the effect of hypoxia on endothelial permeability.

OBJECTIVE

This study investigated the role of nitrite in regulating vascular integrity under hypoxic conditions.

METHODS AND RESULTS

We found denitrosylation and the resulting activation of caspase-3 to be critical for hypoxia-induced endothelial permeability. Nitrite treatment led to S-nitrosylation and the inactivation of caspase-3, suppressing the barrier dysfunction of endothelia caused by hypoxia. This process required the conversion of nitrite to bioactive nitric oxide in a nitrite reductase-dependent manner. Using primary human umbilical vein endothelial cells as a model, we showed that in the presence of nitrite, the S-nitrosylated and inactivated form of caspase-3 was unable to cleave β-catenin, a key component in the VE-cadherin complex. Therefore, nitrite treatment led to the maintenance of VE-cadherin-mediated adherens junctions under hypoxic conditions. In in vivo experiments using a zebrafish model, nitrite was found to protect blood vessels from hypoxia-induced vascular leakage.

CONCLUSIONS

These results are the first to demonstrate that nitrite plays a critical role in the protection of endothelial barrier function against hypoxic insult. Our findings show that nitrite holds great potential for the treatment of diseases associated with hypoxia-induced disorder of vascular homeostasis.

One-time-implantable spinal cord stimulation system prototype

A prototype of a one-time-implantable spinal cord stimulation (SCS) system using wireless power and data-transmission techniques is presented in this paper. The power of the implant is induced by wireless coil coupling, and duplex amplitude-shift keying-load-shift keying wireless communication is used so that digital packets can be transmitted by the same inductive link. The proposed novel ASK demodulator attains high demodulation performance and small area without using any resistors and capacitors. The proposed SCS system utilizes many power saving schemes to reduce power dissipation (e.g., dual supply voltages on-chip, high-voltage impulse generation using small current, etc.). Meanwhile, the excess energy induced by the coils is stored in a rechargeable battery to extend the implant's operation time so that the number of battery replacement surgeries will be reduced significantly. The system-on-chip (SOC) is physically implemented on silicon and integrated in the implant as the system controller. The fabricated SOC area is 1410 × 1710 μm(2). Compared with existing commercial products, the proposed SCS system attains better flexibility and longer operation time.

Association of obesity and smoking with PSA and PSA velocity in men with prostate cancer

Significant number of prostate tumors are slow growing and could probably be left untreated. However, many are aggressive and can spread rapidly causing patient suffering and/or death. Current technology does not allow physicians to differentiate between slow growing and aggressive tumors at diagnosis. Hence, many patients are exposed to invasive treatment and its associated morbidities such as incontinence and impotence. Markers that enable differentiation between slow and fast progressing cancer will allow physicians to prevent unnecessary treatments on men who may not need them, and focus on the men with aggressive disease. A longitudinal study was conducted (N = 140) using mixed effects regression models to determine the association of obesity and smoking toward prostate cancer progression. These models account for correlation because of repeated measures over time, thus, using maximum amount of information provided by the subject. Estimates thus obtained are more robust and reliable than those obtained using data from a single time point. Rate of change of prostate-specific antigen (PSA) over time (PSA velocity) was used as a measure of prostate cancer progression. Results indicate that PSA velocity of overweight and obese subjects (0.59 and 1.05 ng/mL/year) was not significantly different as compared with normal weight subjects (p values .91 and .31, respectively). For men in the highest tertile of pack-years of smoking, PSA velocity was significantly higher as compared with never smokers 1.57 ng/mL/year (p = .04). Further studies with larger sample sizes and study designs specific to above exposures are needed before recommendations can be made to reduce weight or reduce/quit smoking.

A variant of fibroblast growth factor receptor 2 (Fgfr2) regulates left-right asymmetry in zebrafish

Many organs in vertebrates are left-right asymmetrical located. For example, liver is at the right side and stomach is at the left side in human. Fibroblast growth factor (Fgf) signaling is important for left-right asymmetry. To investigate the roles of Fgfr2 signaling in zebrafish left-right asymmetry, we used splicing blocking morpholinos to specifically block the splicing of fgfr2b and fgfr2c variants, respectively. We found that the relative position of the liver and the pancreas were disrupted in fgfr2c morphants. Furthermore, the left-right asymmetry of the heart became random. Expression pattern of the laterality controlling genes, spaw and pitx2c, also became random in the morphants. Furthermore, lefty1 was not expressed in the posterior notochord, indicating that the molecular midline barrier had been disrupted. It was also not expressed in the brain diencephalon. Kupffer's vesicle (KV) size became smaller in fgfr2c morphants. Furthermore, KV cilia were shorter in fgfr2c morphants. We conclude that the fgfr2c isoform plays an important role in the left-right asymmetry during zebrafish development.

Effect of caffeine, norfloxacin and nimesulide on heartbeat and VEGF expression of zebrafish larvae

The use of pharmaceuticals during pregnancy may causes abnormalities to the embryo. Sometime the drug also effect to the new born if the drug transferred through lactation. We have used zebrafish model to see the effect of some pharmaceuticals on embryos and larvae. Three drugs, caffeine, norfloxacin and nimesulide, were used for this study to see the effect mainly the hatching rate of eggs, heart beat rate and the vascular endothelial growth factor (VEGF) expression of the larvae. VEGF is an important signaling protein that involved generating the new blood vessels during embryonic development. We have used 10, 20, 50, 100 microg ml(-1) concentrations of all the drugs to see the effect. No significant mortality or malformations were observed in zebrafish embryos. Hatching was stared from 60 hr. In control group, 91% hatching rate was observed. Lowest hatching rate was observed using highest concentration of norfloxacin (100 microg ml(-1)) and nimesulide (100 microg ml(-1)) i.e. 55 and 56% respectively. In control group, 110 to 115 heart beat rate was counted per minute. Significantly higher heart beat was observed in caffeine treated group which is 125 to 140 min(-1) Lower heart beat was noted in nimesulide treated group which is 100 min(-1). We have tried to observe the possible effect of VEGF of the larvae by these three drugs. Expression of VEGF was very low in caffeine treated group. Almost no VGF expression was observe in 100 microg ml(-1) caffeine treated group. These studies suggest that there is a possibility that high dosage of caffeine can harm the unborn baby or new born babies, if the mothers use caffeine.

A hypothetical relationship between the nuclear reprogramming factors for induced pluripotent stem (iPS) cells generation--bioinformatic and algorithmic approach

A hypothetical evolutionary relationship was generated between the nuclear reprogramming factors for induced pluripotent stem (iPS) cells generation. Utilizing bioinformatics techniques, sequence analyses and phylogenetic tree algorithms, a comparative study has been performed to understand the evolutionary relationship of human nuclear reprogramming factors of induced pluripotent stem cells (iPSCs) generation. Among the total six nuclear reprogramming factors, the four reprogramming factors (SOX2, C-MYC, KLF4, and LIN28) have significant evolutionary origin. Our study shows SOX2 and C-MYC have evolutionary relationship and common point of origin. Likewise, KLF4 and LIN28 are having evolutionary relationship and have common point of origin. Based on these evidences, we propose that our study may be a great help to the future researchers to understand the mechanism(s) as well as pathway of nuclear reprogramming process.

LRRK2 and the stress response: interaction with MKKs and JNK-interacting proteins

Increasing evidence supports a putative link between LRRK2 function and the MAP kinase cascades. We recently demonstrated that LRRK2 binds to MKK6, -3, and -7. Previous studies demonstrated that scaffold proteins are essential in the regulation of subcellular localization of stress kinase complexes. The c-jun NH2-terminal kinase (JNK)-interacting proteins (JIPs) are a group of scaffold proteins that play an important role in the regulation of MAP kinase signaling cascades. JIP1-3 are known to regulate the specificity and localization of the JNK pathway, while JIP4 is a specific scaffolding protein for the p38 pathway. We demonstrate that LRRK2 binds to JIP1-4, and is associated with increased levels of total JIP1, -3, -4, oligomeric JIP and ubiquitinated JIP. These results are consistent with a putative role of LRRK2 in regulating the stress kinase cascade.

Suitability of surface acoustic wave oscillators fabricated using low temperature-grown AlN films on GaN/sapphire as UV sensors

Epitaxial AlN films were prepared on GaN/sapphire using a helicon sputtering system at the low temperature of 300 degrees C. Surface acoustic wave (SAW) devices fabricated on AlN/GaN/sapphire exhibited superior characteristics compared with those made on GaN/sapphire. An oscillator using an AlN/GaN/sapphirebased SAW device is presented. The oscillation frequency decreased when the device was illuminated by ultraviolet (UV) radiation, and the downshift of the oscillation frequency increased with the illuminating UV power density. The results showed that the AlN/GaN/sapphire-layered structure SAW oscillators are suitable for visible blind UV detection and opened up the feasibility of developing remote UV sensors for different ranges of wavelengths on the III-nitrides.

The Soluble Leptin Receptor of Regular Exercisers

This study examined the concentrations and the relationships of soluble leptin receptor (sLR) and leptin levels among both physically active people and lean sedentary persons. Information collected for this study came from twelve joggers (JOG), ten weight trainers (WET) and eleven lean sedentary persons (CON). Regular exercisers were defined as those who consistently participated in jogging or weight training 30 minutes a day, at least four times a week, for a period of no less than three years prior to the study. The CON group was defined as exercising, at most, one time per week, less than 20 minutes each time if at all. Leptin and sLR were analyzed using enzyme-linked immunosorbent assay. The results show the BMI of the WET group to be higher than the other groups, yet their percent body fat was not significantly different. Although sLR levels of the JOG group were higher than the WET and CON groups, their free leptin index (FLI) did not show a significant difference. The sLR levels for joggers were higher than the weight trainers. The sLR concentration or the ratio of sLR to fat mass may be an alternative index to FLI for comparing physically active and lean people.

Equilibrium and kinetics of metal biosorption by sludge from a biological nutrient removal system

This study investigated the biosorption kinetics and equilibrium of cadmium, nickel and zinc by activated sludge from a biological nutrient removal (BNR) process. A series of batch experiments with different initial metal concentrations were conducted to determine the metal removal in BNR sludge. The harvested sludges were from a continuous-flow anaerobic-anoxic-oxic (A2O) system operated under a 10 days of sludge retention time. Batch tests were specially designed to isolate the precipitation effects of metal ions in solution so as to compare the isotherm constants of biosorption with and without precipitation isolation. Experimental results revealed that BNR sludge exhibited two stages of biosorption, i.e., passive and then active uptake, for all three metals. The biosorption kinetic data of three tested metals can be effectively simulated by pseudo-second-order rate equations. Besides, the biosorption isotherm showed that metal biosorption behavior was statistically in agreement with the Freundlich model. The capacity constants k of the Freundlich model for Cd, Ni and Zn are 0.50, 0.23 and 0.41; the affinity constants 1 / n are 0.96, 0.81 and 0.31, respectively. Additionally, precipitation behaviors of metals obviously should be carefully examined during biosorption batch tests with activated sludge; otherwise the biosorption effect could be significantly overestimated.

Phase II study of weekly vinorelbine and 24-h infusion of high-dose 5-fluorouracil plus leucovorin as first-line treatment of advanced breast cancer

We prospectively investigated the efficacy and safety of combining weekly vinorelbine (VNB) with weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) and leucovorin (LV) in the treatment of patients with advanced breast cancer (ABC). Vinorelbine 25 mg m⁻² 30-min intravenous infusion, and high-dose 5-FU 2600 mg m⁻² plus LV 300 mg m⁻² 24-h intravenous infusion (HDFL regimen) were given on days 1 and 8 every 3 weeks. Between June 1999 and April 2003, 40 patients with histologically confirmed recurrent or metastatic breast cancer were enrolled with a median age of 49 years (range: 36–68). A total of 25 patients had recurrent ABC, and 15 patients had primary metastatic diseases. The overall response rate for the intent-to-treat group was 70.0% (95% CI: 54–84%) with eight complete responses and 20 partial responses. All 40 patients were evaluated for survival and toxicities. Among a total of 316 cycles of VNB–HDFL given (average: 7.9: range: 4–14 cycles per patient), the main toxicity was Gr3/4 leucopenia and Gr3/4 neutropenia in 57 (18.0%) and 120 (38.0%) cycles, respectively. Gr1/2 infection and Gr1/2 stomatitis were noted in five (1.6%) and 59 (18.7%) cycles, respectively. None of the patients developed Gr3/4 stomatitis or Gr3/4 infection. Gr2/3 and Gr1 hand–foot syndrome was noted in two (5.0%) and 23 (57.5%) patients, respectively. Gr1 sensory neuropathy developed in three patients. The median time to progression was 8.0 months (range: 3–25.5 months), and the median overall survival was 25.0 months with a follow-up of 5.5 to 45+ months. This VNB–HDFL regimen is a highly active yet well-tolerated first-line treatment for ABC.

A feasibility study on the predictive emission monitoring system applied to the Hsinta power plant of Taiwan Power Company

The continuous emission monitoring system (CEMS) can monitor flue gas emissions continuously and instantaneously. However, it has the disadvantages of enormous cost, easily producing errors in sampling periods of bad weather, lagging response in variable ambient environments, and missing data in daily zero and span tests and maintenance. The concept of a predictive emission monitoring system (PEMS) is to use the operating parameters of combustion equipment through thermodynamic or statistical methods to construct a mathematic model that can predict emissions by a computer program. The goal of this study is to set up a PEMS in a gas-fired combined cycle power generation unit at the Hsinta station of Taiwan Power Co. The emissions to be monitored include nitrogen oxides (NOx) and oxygen (O2) in flue gas. The major variables of the predictive model were determined based on the combustion theory. The data of these variables then were analyzed to establish a regression model. From the regression results, the influences of these variables are discussed and the predicted values are compared with the CEMS data for accuracy. In addition, according to the cost information, the capital and operation and maintenance costs for a PEMS can be much lower than those for a CEMS.

Microbial iron respiration can protect steel from corrosion

Microbiologically influenced corrosion (MC) of steel has been attributed to the activity of biofilms that include anaerobic microorganisms such as iron-respiring bacteria, yet the mechanisms by which these organisms influence corrosion have been unclear. To study this process, we generated mutants of the iron-respiring bacterium Shewanella oneidensis strain MR-1 that were defective in biofilm formation and/or iron reduction. Electrochemical impedance spectroscopy was used to determine changes in the corrosion rate and corrosion potential as a function of time for these mutants in comparison to the wild type. Counter to prevailing theories of MC, our results indicate that biofilms comprising iron-respiring bacteria may reduce rather than accelerate the corrosion rate of steel. Corrosion inhibition appears to be due to reduction of ferric ions to ferrous ions and increased consumption of oxygen, both of which are direct consequences of microbial respiration.

Importance of early phase insulin secretion to intravenous glucose tolerance in subjects with type 2 diabetes mellitus

Insulin secretion is impaired in type 2 diabetes with the early response being essentially absent. The loss of this early insulin secretion is hypothesized to be important in the deterioration of glucose tolerance. To determine whether enhancement of the early-phase insulin response can enhance glucose tolerance, we administered 1) 120 mg nateglinide, an insulinotropic agent that enhances early insulin secretion; 2) 10 mg glyburide, which enhances the later phases of insulin secretion; or 3) placebo in random order to 21 subjects with type 2 diabetes (14 males and 7 females; aged 59.2 +/- 2.1 yr, x +/- SEM; body mass index 29.7 +/- 1.0 kg/m(2); fasting plasma glucose 8.1 +/- 0.1 mM). beta-Cell function was quantified as the incremental area under the curve for different time periods for the 5 h following iv glucose administration and glucose tolerance as the glucose disappearance constant (Kg) from 10 to 60 min. Insulin release commenced immediately after nateglinide administration, even before glucose injection, but this was not observed with glyburide. Both nateglinide and glyburide enhanced glucose-induced insulin release, compared with placebo (area under the curve -15-300 min: nateglinide 23,595 +/- 11,212 pM/min, glyburide 54,556 +/- 15,253 pM/min, placebo 10,242 +/- 2,414 pM/min). The profiles of insulin release demonstrated significant enhancement of release between -15 and 30 min for nateglinide, compared with glyburide and between 60 and 300 min for glyburide over nateglinide. Kg increased by 15% with nateglinide (0.87 +/- 0.04%/min), but it did not increase significantly with glyburide (0.79 +/- 0.04%/min), compared with placebo (0.76 +/- 0.04%/min). The enhancement of insulin release by glyburide resulted in a lower minimal glucose concentration with glyburide (3.8 +/- 0.2 mM), compared with nateglinide (5.0 +/- 0.2 mM) and placebo (5.9 +/- 0.2 mM). Thus, enhancement of the early phase of insulin secretion improves iv glucose tolerance, whereas delaying it by 30 min results in a slower rate of glucose disappearance for the first 2 h after iv glucose administration. Further, the differences in the kinetics of nateglinide and glyburide action results in continued insulin release with glyburide despite the fact that glucose levels have returned to basal, thus resulting in a further reduction in glucose levels and a lower nadir.

Estimation for paired binomial data with application to radiation therapy

We compare and contrast several different methods for estimating the effect of treatment when responses are paired binomial observations. The ratio of binomial probabilities is the parameter of interest, while the binomial probabilities are nuisance parameters which may vary between pairs. The application is a meta-analysis of the treatment of rectal cancer, with observations in each study indicating the number of recurrences of the cancer in each of two groups, one with radiation therapy and one without. The ratio of the probabilities of recurrence in the radiation to non-radiation groups is of substantive interest, and is modelled as a logistic or complementary log-log function of an unknown linear combination of the covariates. The three methods we consider are maximum likelihood, a Bayesian approach and an approach based on estimating equations. For the MLE and Bayesian approach the potentially large number of nuisance parameters are estimated together with the parameters of interest, whereas for the estimating equation approach only the parameters of interest are estimated. A simulation study is performed to compare the methods and evaluate the impact of overdispersion.

Solution structure of a Kunitz-type chymotrypsin inhibitor isolated from the elapid snake Bungarus fasciatus

Bungarus fasciatus fraction IX (BF9), a chymotrypsin inhibitor, consists of 65 amino acid residues with three disulfide bridges. It was isolated from the snake venom of B. fasciatus by ion-exchange chromatography and belongs to the bovine pancreatic trypsin inhibitor (BPTI)-like superfamily. It showed a dissociation constant of 5.8 x 10(-8) m with alpha-chymotrypsin as measured by a BIAcore binding assay system. The isothermal titration calorimetry revealed a 1:1 binding stoichiometry between this inhibitor and chymotrypsin and apparently no binding with trypsin. We further used CD and NMR to determine the solution structure of this venom-derived chymotrypsin inhibitor. The three-dimensional NMR solution structures of BF9 were determined on the basis of 582 restraints by simulated annealing and energy minimization calculations. The final set of 10 NMR structures was well defined, with average root mean square deviations of 0.47 A for the backbone atoms in the secondary structure regions and 0.86 A for residues The side chains of Phe(23), Tyr(24), Tyr(25), Phe(35), and Phe(47) exhibited many long-range nuclear Overhauser effects and were the principal components of the hydrophobic core in BF9. To gain insight into the structure-function relationships among proteins in the BPTI-like superfamily, we compared the three-dimensional structure of BF9 with three BPTI-like proteins that possess distinct biological functions. These proteins possessed similar secondary structure elements, but the loop regions and beta-turn were different from one another. Based on residues at the functional site of each protein, we suggest that the flexibility, rigidity, and variations of the amino acid residues in both the loop and beta-turn regions are related to their biological functions.

The p53 codon 249 mutant--derived from human functional adrenal tumors--can modify the cell shape of normal adrenocortical transfected cells

Our previous study has indicated that p53 gene mutation occurred in 73% of human functional adrenal tumors, and the mutation hot spots were focused on codons 100, 102 (exon 4), and 249 (exon 7). Furthermore, a transcriptional activity study revealed that the mutant p53 protein derived from human functional adrenal tumors lost 90% transcriptional activity and the ability to bind with the p53 sequence. In order to investigate the influence of the mutant protein extracted from adrenocortical tumors on normal adrenal cells, we first cloned p53 cDNA from the human primary aldosteronism and constituted it with isopropyl thiogalactoside (IPTG) inducible expression vector as recombinant plasmid. The recombinant plasmid was then transfected to normal bovine adrenocortical cells through electroporation. The results showed that the p53 protein mutations at codons 100 and 102 could neither affect the cell morphology nor enable cell growth on the soft agar. In addition, no significant difference was found in cortisol level between the p53 transfected and the control cells. On the other hand, cell morphological changes and cell proliferation rate increase were observed when we used IPTG to induce the expression of the p53 protein, which mutated at codon 249, in adrenocortical cells. The cell morphology changes included less flattened and decreased elongation when compared to non-transfected cells. However, the cortisol level in transfected cells was not affected by the p53 mutants. Taken together, we concluded that the mutant p53 protein indeed participates in adrenal carcinogenesis; however, it has no influence on hormone production and secretion.