Quantum criticality and nodal superconductivity in the FeAs-based superconductor KFe2As2

The in-plane resistivity rho and thermal conductivity kappa of the FeAs-based superconductor KFe2As2 single crystal were measured down to 50 mK. We observe non-Fermi-liquid behavior rho(T) approximately T{1.5} at H{c{2}}=5 T, and the development of a Fermi liquid state with rho(T) approximately T{2} when further increasing the field. This suggests a field-induced quantum critical point, occurring at the superconducting upper critical field H{c{2}}. In zero field, there is a large residual linear term kappa{0}/T, and the field dependence of kappa_{0}/T mimics that in d-wave cuprate superconductors. This indicates that the superconducting gaps in KFe2As2 have nodes, likely d-wave symmetry. Such a nodal superconductivity is attributed to the antiferromagnetic spin fluctuations near the quantum critical point.

Quantitation of thyroid-stimulating hormone receptor mRNA with real-time PCR for early diagnosis of papillary thyroid microcarcinoma

Recently, the value of thyroid-stimulating hormone receptor(TSHR) mRNA as a molecular marker in diagnosis of thyroid cancer has been greatly explored. However, its role in detecting thyroid microcarcinoma has never been reported. In this study, we aim to investigate the value of TSHR mRNA in diagnosis of papillary thyroid microcarcinoma(PTMC). To do that, TSHR mRNA levels were measured by real time PCR in 30 healthy subjects and 72 patients (benign thyroid nodules, n=38; PTMC, n=34). TSHR mRNA levels were then compared with cancer volume in surgical specimen. We found that TSHR mRNA levels in PTMC were significantly higher than benign thyroid nodules(P<0.01). At a cutoff value of 0.71 ng/microg total RNA, the TSHR mRNA correctly classified 77.8% of patients preoperatively (sensitivity= 76.5%; specificity= 79.4%). Comparatively, it performed better in larger PTMC of 0.5-1.0 cm than <0.5 cm(sensitivity, 83.4% vs 72.4%; specificity, 88.5% vs 74.1%). Combining TSHR mRNA and ultra sound examination correctly detect 97.1% of PTMC and could spared surgery in 86.8% of patients with benign thyroid nodules. Thus, TSHR mRNA measured with real time PCR enhances the preoperative detection of PTMC in patients with thyroid nodules, which dramatically reduces unnecessary surgeries.

KEYWORDS

thyroid-stimulating hormone receptor, papillary thyroid microcarcinoma, diagnosis.

Search for axions with the CDMS experiment

We report on the first axion search results from the Cryogenic Dark Matter Search (CDMS) experiment at the Soudan Underground Laboratory. An energy threshold of 2 keV for electron-recoil events allows a search for possible solar axion conversion into photons or local galactic axion conversion into electrons in the germanium crystal detectors. The solar axion search sets an upper limit on the Primakov coupling g(agammagamma) of 2.4x10(-9) GeV-1 at the 95% confidence level for an axion mass less than 0.1 keV/c2. This limit benefits from the first precise measurement of the absolute crystal plane orientations in this type of experiment. The galactic axion search analysis sets a world-leading experimental upper limit on the axioelectric coupling g(aee) of 1.4x10(-12) at the 90% confidence level for an axion mass of 2.5 keV/c2.

Search for weakly interacting massive particles with the first five-tower data from the cryogenic dark matter search at the soudan underground laboratory

We report results from the Cryogenic Dark Matter Search at the Soudan Underground Laboratory (CDMS II) featuring the full complement of 30 detectors. A blind analysis of data taken between October 2006 and July 2007 sets an upper limit on the weakly interacting massive particle (WIMP) nucleon spin-independent cross section of 6.6x10;{-44} cm;{2} (4.6x10;{-44} cm;{2} when combined with previous CDMS II data) at the 90% confidence level for a WIMP mass of 60 GeV/c;{2}. This achieves the best sensitivity for dark matter WIMPs with masses above 44 GeV/c;{2}, and significantly restricts the parameter space for some favored supersymmetric models.

CCDC134, a novel secretory protein, inhibits activation of ERK and JNK, but not p38 MAPK

In this study, we report a novel gene, CCDC134 (coiled-coil domain containing 134), that encodes a secretory protein that can inhibit the MAPK pathway as a novel human MAPK-regulating protein. The CCDC134 mRNA contains 1280 nucleotides, encoding a protein of 229 amino acids. CCDC134 is a classical secretory protein. Expression profile analysis by Northern blot, RT-PCR, immunohistochemistry and Western blot reveals that CCDC134 is widely expressed in normal adult tissues, tumor tissues and cell lines. Functional investigation reveals that overexpression of CCDC134 and its purified protein significantly inhibit transcriptional activity of Elk1 and phosphorylation of Erk and JNK/SAPK but not p38 MAPK. Conversely, specific siRNA against CCDC134 activates Elk1 transcriptional activity and promotes Erk and JNK/SAPK phosphorylation. These results clearly indicate that CCDC134 is a novel member of the secretory family and down-regulates the Raf-1/MEK/ERK and JNK/ SAPK pathways.

Effects of preshipping management on measures of stress and performance of beef steers during feedlot receiving

Over 2 yr, a total of 96 steers (approximately 7 mo of age) were allocated to 1 of 4 weaning management strategies: 1) control: weaned on the day of shipping; 2) creep-fed: allowed free-choice access to concentrate before weaning and shipping; 3) preweaned: weaned and provided supplemental concentrate on pasture before shipping; and 4) early-weaned: weaned at 70 to 90 d of age and kept on pasture. On the day of shipping, steers were loaded together onto a commercial livestock trailer and transported 1,600 km over 24 h before being received into the feedlot. At the feedlot, steers were penned by treatment (4 pens/treatment) and provided access to free-choice hay and concentrate in separate feeding spaces. Samples of blood were collected on d 0, 1, 4, 8, 15, 22, and 29 relative to shipping. Steer performance was assessed over the receiving period, including DMI of hay and concentrate, ADG, and G:F. Predetermined contrasts included control vs. early-weaned, creep-fed vs. preweaned, and control vs. creep-fed and preweaned. Overall ADG was greater (P < 0.01) for early-weaned vs. control steers (1.39 vs. 0.88 kg). In wk 1, early-weaned steers consumed more concentrate and less hay compared with control steers (P < 0.03), and preweaned steers consumed more concentrate (P < 0.01) but a similar amount of hay (P = 0.75) compared with creep-fed steers. Average DMI was greater for preweaned compared with creep-fed steers (2.84 vs. 2.50% of BW; P = 0.01) and tended to be greater for early-weaned compared with control steers (2.76 vs. 2.50% of BW; P = 0.06). Feed efficiency of early-weaned steers was greater than that of control steers (G:F = 0.17 vs. 0.12; P < 0.01) but similar for preweaned compared with creep-fed steers (P = 0.72). Plasma ceruloplasmin concentrations were less (P < 0.05) in control vs. early-weaned steers on d 0, but increased sharply after shipping and were greater in control vs. early-weaned steers on d 15 and 22 (P < 0.05). Creep-fed steers also experienced greater (P < 0.05) plasma ceruloplasmin concentrations than preweaned steers on d 29. These data suggest that early-weaned steers have improved performance in the feedlot compared with steers weaned directly before transport and feedlot entry. Differences in preshipping management appear to significantly affect measures of the acute phase protein response in steers.

The digestive fate of Escherichia coli glutamate dehydrogenase deoxyribonucleic acid from transgenic corn in diets fed to weanling pigs

Corn containing genetically engineered plasmid DNA encoding an Escherichia coli glutamate dehydrogenase (gdhA) was fed to 19-d-old weanling swine to trace the digestive fate of the transgenic DNA. Eight pens of 8 pigs were fed a commercial (nongdhA) starter for 2 wk. One pig was randomly selected from each pen for 0-h control samples. The remaining 56 pigs were transitioned onto a corn-soybean meal diet and fed a diet containing 58% gdhA corn for approximately 1 wk; immediately thereafter, liver, 10th rib muscle, white blood cells, and plasma from the hepatic portal vein and ingesta from the stomach, distal ileum, and large intestine were collected. The DNA was extracted and the concentration determined via spectrophotometry. Polymerase chain reaction and gel electrophoresis were performed with primers designed to amplify 490 bp that included the plasmid's ligation site between the maize ubiquitin and the gdhA genes. The gdhA corn-derived DNA and diet served as positive assay controls, and conventional corn DNA and distilled water acted as negative assay controls. Detection limits were 0.99 fg of target DNA confounded with 500 ng of conventional corn DNA per each 20 &L reaction. Transgenic DNA was detected in 71.43% of the stomach and 1.79% of the ileal ingesta samples from treatment animals but was not detected in the large intestine, white blood cells, plasma, liver, or muscle samples. Transgenic DNA was not detected in any sample from 0-h control animals. Stomach and ileal ingesta samples were further analyzed using real-time PCR. With an estimated limit of detection of 1.049 ag/microL, 89.29% of the stomach ingesta samples were positive (average 1.56 fg target DNA). The proportion of transgenic DNA to total DNA differed between diet and stomach ingesta samples (P < 0.001). Despite the greater sensitivity of real-time PCR, target DNA was detected in only 1.79% of ileal ingesta. These data suggest that the gdhA transgene began degradation in the stomach and was nondetectable in the large intestine.

Genetic effects on acute phase protein response to the stresses of weaning and transportation in beef calves

The objective herein was to estimate heterosis and breed effects in purebred and crossbred Romosinuano, Brahman, and Angus calves on acute phase protein response to weaning and transportation. Calves (n = 1,032) were weaned in September of 2002, 2003, and 2004 at approximately 7 mo of age. Approximately 28 d after weaning, steer calves (n = 482) were transported 1,800 km (20 h) to Oklahoma. Concentrations of 3 acute phase proteins (ceruloplasmin, fibrinogen, and haptoglobin) were measured in blood samples. Calves (steers and heifers) were sampled at weaning, and 24 and 72 h postweaning. For separate analyses, steers sent to Oklahoma were sampled before shipment, upon arrival, and 24 and 72 h after arrival. Combinations of the following fixed effects were investigated: sire breed, dam breed, sampling time, birth location, calf sex (weaning only), year, cow age, and interactions. Effects of special interest were sire breed x dam breed as an indication of breed group of calf, and the interaction of sire and dam breeds with sampling time. Weaning age and BW were investigated as linear and quadratic covariates. Sire of calf within sire breed was a random term. The correlation structure of repeated measures was determined by comparison of information criterion values for different structures within each analysis. In general, plasma acute phase protein concentrations in weaned calves increased with sampling time. Concentrations in the transported steers increased through sampling at 24 h after arrival, and were lower at 72 h. Significant estimates of heterosis were detected for Brahman-Angus haptoglobin concentrations at weaning (0.38 +/- 0.14 mg/dL x 100; 44%), and for Romosinuano-Angus fibrinogen concentrations at weaning (11.4 +/- 5.5 mg/dL; 10%) and in transported steers (22.5 +/- 8.4 mg/dL; 20%). The direct effect of Romosinuano was to increase (P <0.004) ceruloplasmin concentrations of weaned calves (4.1 +/- 0.9 mg/dL) and of transported steers (3.9 +/- 1.3 mg/dL). The direct effect of Angus was to lower ceruloplasmin concentrations in weaned calves (-3.9 +/- 1.2; P = 0.001). Significant maternal effects were detected at weaning for ceruloplasmin concentrations in Romosinuano (-1.4 +/- 0.5 mg/ dL) and Angus (1.6 +/- 0.7 mg/dL) and fibrinogen concentrations in Brahman calves (-17.7 +/- 8.8 mg/dL). These data imply that acute phase protein concentrations in response to weaning and transportation are impacted by cattle breed.

Immunohistochemical expression and colocalization of somatostatin, carboxypeptidase-E and prohormone convertases 1 and 2 in rat brain

The processing of many peptides for their maturation in target tissue depends upon the presence of sorting receptor. Several previous studies have predicted that carboxypeptidase-E (CPE), prohormone convertase 1 (PC1) and prohormone convertase 2 (PC2) may function as sorting elements for somatostatin (SST) for its maturation and processing to appropriate targets. However, nothing is currently known about whether brain, neuronal culture or even endocrine cells express SST, CPE, PC1 and PC2 and exhibit colocalization. Accordingly, in the present study using peroxidase immunohistochemistry, double-labeled indirect immunofluorescence immunohistochemistry and Western blot analysis, we mapped the distributional pattern of SST, CPE, PC1 and PC2 in different rat brain regions. Additionally, we also determined the colocalization of SST with CPE, PC1 and PC2 as well as colocalization of CPE with PC1 and PC2. The localization of SST, CPE, PC1 and PC2 reveals a distinct and region specific distribution pattern in the rat brain. Using an indirect double-label immunofluorescence method we observed selective neuron specific colocalization in a region specific manner in cortex, striatum and hippocampus. These studies provide the first evidence for colocalization between SST, CPE, PC1 and PC2 as well as CPE with PC1 and PC2. SST in cerebral cortex colocalized in pyramidal and non-pyramidal neurons with CPE, PC1 and PC2. Most importantly, in striatum and hippocampus colocalization was mostly observed selectively and preferentially in interneurons. CPE is also colocalized with PC1 and PC2 in a region specific manner. The data presented here provide a new insight into the distribution and colocalization of SST, CPE, PC1 and PC2 in rat brain. Taken together, our data anticipate the possibility that CPE, PC1 and PC2 might be potential target for the maturation of SST.

Environmental hazard analysis and effective remediation of highway seepage

Risk assessment and minimisation of environmental hazards are critical issues to consider in the geotechnical engineering projects. A case of highway pavement seepage induced by groundwater, at a locality along the section of Hua-Qing Highway of Guangdong Province, China, is presented for environmental hazard analysis and effective remediation. The environmental hazard analyses were based on in situ hydrogeologic investigation, rock-soil testing and integrated environmental understanding. The analyses indicate that the highway seepage was caused by elevation of groundwater hydraulic pressure in low permeable strata near the highway pavement, which was controlled by landform, hydrology, weather and road structure. The risk source of groundwater 'flooding' was the groundwater and surface water in the ring-like valley around Fenshui Village. A blind-ditch system for effective remediation of the pavement seepage hazard was proposed and successfully implemented by declining groundwater table near the highway based on the comprehensive assessment of various conditions. This geotechnical accident shows that the role of groundwater is an essential factor to consider in the geotechnical and environmental engineering studies and multidisciplinary effort for risk assessment of environmental hazards is important under current global climate change condition.

Epigenetics, disease, and therapeutic interventions

Heritable changes in gene expression that do not involve coding sequence modifications are referred to as "epigenetic". Epigenetic mechanisms principally include DNA methylation and a variety of histone modifications, of which the best characterized is acetylation. DNA hypermethylation and histone hypoacetylation are hallmarks of gene silencing, while DNA hypomethylation and acetylated histones promote active transcription. Aberrant DNA methylation and histone acetylation have been linked to a number of age related disorders including cancer, autoimmune disorders and others. Since epigenetic alterations are reversible, modifying epigenetic marks contributing to disease development may provide an approach to designing new therapies. Herein we review the role of epigenetic changes in disease development, and recent advances in the therapeutic modification of epigenetic marks.

Livin promotes Smac/DIABLO degradation by ubiquitin-proteasome pathway

Livin, a member of the inhibitor of apoptosis protein (IAP) family, encodes a protein containing a single baculoviral IAP repeat (BIR) domain and a COOH-terminal RING finger domain. It has been reported that Livin directly interacts with caspase-3 and -7 in vitro and caspase-9 in vivo via its BIR domain and is negatively regulated by Smac/DIABLO. Nonetheless, the detailed mechanism underlying its antiapoptotic function has not yet been fully characterized. In this report, we provide, for the first time, the evidence that Livin can act as an E3 ubiquitin ligase for targeting the degradation of Smac/DIABLO. Both BIR domain and RING finger domain of Livin are required for this degradation in vitro and in vivo. We also demonstrate that Livin is an unstable protein with a half-life of less than 4 h in living cells. The RING domain of Livin promotes its auto-ubiquitination, whereas the BIR domain is likely to display degradation-inhibitory activity. Mutation in the Livin BIR domain greatly enhances its instability and nullifies its binding to Smac/DIABLO, resulting in a reduced antiapoptosis inhibition. Our findings provide a novel function of Livin: it exhibits E3 ubiquitin ligase activity to degrade the pivotal apoptotic regulator Smac/DIABLO through the ubiquitin-proteasome pathway.

Chronic treatment with vascular endothelial growth factor preserves agonist-evoked vascular responses in the streptozotocin-induced diabetic rat

AIMS/HYPOTHESIS

Vascular dysfunction is a hallmark of diabetes mellitus and endothelial dysfunction is considered to be a key early component of vascular dysfunction. Attenuated agonist-evoked responses are considered to be a barometer of endothelial/vascular dysfunction. We sought to determine whether vascular endothelial growth factor (VEGF) could prevent dysfunction from developing in the streptozotocin (STZ)-induced rat model of type 1 diabetes.

MATERIALS AND METHODS

One week after induction of diabetes, STZ rats began a 4-week treatment protocol of twice-weekly i.v. injections of 2 microg VEGF or inactivated VEGF. Corresponding non-diabetic rats served as controls. Agonist-evoked vascular responses were recorded 1 day after the last treatment in anaesthetised rats.

RESULTS

Acetylcholine (0.1-12.5 microg/kg) evoked increases in superior mesenteric arterial conductance and decreases in mean blood pressure, while methoxamine (12.5-100 microg/kg) and endothelin-1 (100-1,200 pmol/kg) evoked decreases in superior mesenteric arterial conductance and increases in mean blood pressure. These responses to all three agonists were attenuated in STZ rats, and chronic treatment with VEGF improved these responses dramatically. Both the reduction in plasma nitrate and nitrite and the elevation in aortic superoxide associated with STZ diabetes were normalised with VEGF treatment. VEGF also prevented the apparent paradoxical increased endothelial nitric oxide synthase expression seen in untreated STZ rats.

CONCLUSIONS/INTERPRETATION

Chronic treatment with VEGF early in diabetes is able to prevent the attenuated agonist-evoked vascular responses in STZ rats and normalise the oxidative environment associated with the disease.

Novel tiO2 nanocatalysts for wastewater purification: tapping energy from the sun

Water treatment using TiO2 semiconductor as a durable heterogeneous photocatalyst has been the focus of environmentalists in recent years. Currently, we developed an inexpensive and highly efficient approach for synthesizing nitrogen-doped TiO2 with lower band-gap energy that can respond to visible light. Doping on the molecular scale led to an enhanced nitrogen concentration of up to 21.8%. Reflectance measurements showed the synthesized N-doped TiO2 nanoparticles are catalytically active with the absorbance that extends into the visible region up to 600 nm. The water purification potential of this new class of compound was evaluated by studying the photodegradation of Acid Orange 7 (AO7) and E. coli. Experiments were conducted to compare the photocatalytic activities of N-doped TiO2 nanocatalysts and commercially available Degussa P25 power under identical solar light exposure. N-doped TiO2 demonstrated superior photocatalytic activities in both chemical compound degradation and bactericidal reactions. The result of this study shows the potential of applying new generations of catalyst for wastewater purification and disinfection.

Activation of antitumor cytotoxic T lymphocytes by fusion of patient-derived dendritic cells with autologous osteosarcoma

BACKGROUND AND AIM

Fusion of human dendritic cells (DCs) with tumor cells is an effective approach for delivering tumor antigens to DCs, and DC/tumor fusion cells are potent stimulators of autologous T cells. However, the integration and morphology of DC/osteosarcoma fusion cells has not been examined. This study was designed to investigate the antitumor effects of tumor vaccine produced by electrofusion between human osteosarcoma cells and DCs.

METHODS

In the present study, we eletrofused patient-derived DCs to autologous osteosarcoma cells. The fusion cells possessed the properties of both patient cells. After electrofusion, the cytoplasm of the two cells was integrated, whereas their nuclei remained separate entities. The intracellular structure was observed on fusion cells under the transmission electron microscope.

RESULTS

Coculture of patient-derived peripheral blood mononuclear cells (PBMC) with DC/tumor fusion cells resulted in activation of T cells as assessed by standard cytotoxic T lymphocytes (CTLs) assays.

CONCLUSIONS

The present study provides valid evidence on integration of human DCs and tumor cells and links their properties to T cell activation. The fusion cells may thus represent a promising strategy for DC-based immunotherapy of patients with osteosarcoma.

Effects of Dry Matter Intake, Addition of Buffer, and Source of Fat on Duodenal Flow and Concentration of Conjugated Linoleic Acid and Trans-11 C18:1 in Milk

The primary objective of the study was to investigate the effects of DM intake, addition of buffer, and fish vs. soybean oil on duodenal flows and milk concentrations of conjugated linoleic acid (CLA) and trans-11 C18:1. Four ruminally and duodenally cannulated multiparous cows averaging 106 +/- 17 d in milk at the start of the trial were used in a 4 x 4 Latin square design with treatments as follows: 1) control=diet contained 2% fish oil and fed ad libitum, 2) buffer addition (BUFF)=control diet with 0.8% of NaHCO3 added, 3) low DM intake (LDMI)=DMI restricted to 80% of the control but concentration of fish oil was increased to 2.5% to provide for similar fatty acids (FA) intake, and 4) soybean oil (SBO)=same as control except 2% soybean oil was substituted for fish oil. The diets consisted of 36.2% forage and 63.8% concentrate. Each period consisted of 18 d, with the last 7 d devoted to data collection and the first 4 d used to determine the appropriate amount of feed to be offered to the cow on LDMI. Duodenal flows of CLA and trans-C18:1 were lower for SBO than for diets with fish oil. Feeding buffer did not affect ruminal pH or duodenal flows of trans-11 C18:1 and CLA. Restriction of DMI decreased duodenal flow of trans-11 C18:1 but did not decrease duodenal flow of CLA compared with control. In milk, CLA concentration was lower for SBO (24.5, 17.9, 18.5, and 10.1 mg/g of FA for control, BUFF, LDMI, and SBO, respectively). Cows fed fish oil had higher duodenal flow and milk concentration of n-3 polyunsaturated fatty acids than the cows fed SBO. Compared with SBO, fish oil is more effective in increasing duodenal flows of CLA and trans-11 C18:1, and thus, concentration of CLA in milk.

Effects of Substrate, Passage Rate, and pH in Continuous Culture on Flows of Conjugated Linoleic Acid and Trans C18:1

A dual-flow continuous culture system consisting of 4 fermenters was used in a 4 x4 Latin square design. The objective of the research was to evaluate the effects of solid dilution rate (SDR), pH, and concentration of linoleic acid (LA) in the feed mixture on the production of conjugated linoleic acid (CLA) and trans-C18:1. The 4 treatments were 1) control = pH 6.5, 1% LA, 4%/h SDR; 2) high solid dilution rate (HSDR) = pH 6.5, 1% LA, 8%/h SDR; 3) high linoleic acid (HLA) = pH 6.5, 3% LA, 4%/h SDR; and 4) low pH (LPH) = pH 5.8, 1% LA, 4%/h SDR. Inoculum was collected 6 h after feeding from a cow fed 40% alfalfa hay and 60% grain. Liquid dilution rate was held at 0.12/h. All treatments except HLA contained 2% tallow. The LA was dissolved in buffer and continuously infused into the fermenters. The CLA flows were 16.5, 20.4, 23.2, and 25.2 mg/d for control, HSDR, HLA, and LPH, respectively. Compared with control, LPH increased flows of CLA, cis-C18:1, and C18:2, and decreased flow of C18:0. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) digestibilities were not affected by pH. The HSDR tended to increase CLA flow compared to control, possibly because a shorter solid retention time led to incomplete biohydrogenation (BH). The NDF and ADF digestibilities and bacterial numbers were reduced by HSDR. With more LA available as a substrate for CLA, HLA resulted in a higher flow of CLA than control. The HLA resulted in the highest acid detergent fiber and fatty acid digestibilities, bacterial numbers, and BH. Increasing solids passage rate, reducing pH, and increasing dietary LA appears to increase in vitro CLA production.

Effects of Corn Silage Hybrid and Dietary Concentration of Forage NDF on Digestibility and Performance by Dairy Cows

Eight intact multiparous cows and four ruminally and duodenally cannulated primiparous cows were fed four diets in a replicated 4 x 4 Latin square design: 1) 17% forage neutral detergent fiber (NDF) with brown midrib corn silage (BMRCS), 2) 21% forage NDF with BMRCS, 3) 17% forage NDF with conventional corn silage (CCS), and 4) 21% forage NDF with CCS. Diets contained 17.4% crude protein and 38.5% NDF. Each period consisted of 4 wk for intact cows and 2 wk for cannulated cows. For intact cows, DM intake was higher for BMRCS than CCS, and milk urea N was higher for 21 than 17% forage NDF. Milk protein yield tended to be higher and milk urea N lower for cows fed BMRCS than those fed CCS. Milk yield and milk protein percentage were similar among treatments. For the cannulated cows, ruminal mat consistency was similar among treatments. Based on a 72 h in situ incubation, BMRCS was lower in indigestible NDF than CCS. The BMRCS resulted in a higher proportion of ruminal propionate than CCS. Cows fed 21% forage NDF had a higher proportion of acetate and a lower proportion of propionate than cows fed 17% forage NDF. The total tract digestibility of nutrients and efficiency of bacterial N synthesis were similar among treatments, except that BMRCS resulted in lower intestinal fatty acid digestibility than CCS, and 17% forage NDF tended to result in higher total tract fatty acid digestibility than 21% forage NDF. Ruminal NDF digestibility was similar among dietary treatments. The increased milk production observed from feeding BMRCS in some studies may be explained by higher DM intake rather than increased total tract digestibility of the diets.

Evolution of an organophosphate-degrading enzyme: a comparison of natural and directed evolution

Organophosphate-degrading enzyme from Agrobacterium radiobacter P230 (OPDA) is a recently discovered enzyme that degrades a broad range of organophosphates. It is very similar to OPH first isolated from Pseudomonas diminuta MG. Despite a high level of sequence identity, OPH and OPDA exhibit different substrate specificities. We report here the structure of OPDA and identify regions of the protein that are likely to give it a preference for substrates that have shorter alkyl substituents. Directed evolution was used to evolve a series of OPH mutants that had activities similar to those of OPDA. Mutants were selected for on the basis of their ability to degrade a number of substrates. The mutations tended to cluster in particular regions of the protein and in most cases, these regions were where OPH and OPDA had significant differences in their sequences.

The photoreceptor localization confirms the spectral heterogeneity of ommatidia in the male small white butterfly, Pieris rapae crucivora

The compound eye of Pieris rapae crucivora contains ventrally three types of histologically distinct ommatidia. An ommatidium contains nine photoreceptors, four of which (R1-4) construct the distal tier of the rhabdom. We determined the sensitivity spectra of the R1-4 distal photoreceptors in each type of ommatidia by intracellular electrophysiology and identified UV, blue, double-peaked blue, green, and a green receptor with depressed sensitivity in the violet. We localized these receptors in each type of ommatidia by injecting dye after the recording. In type I ommatidia the R1 and R2 cells are UV and blue receptors. When R1 is UV sensitive, R2 is always blue sensitive, or vice versa. R3 and R4 in type I are both green receptors. In type II, R1 and R2 are both double-peaked blue receptors and R3 and R4 are both green receptors with depressed sensitivity in the violet. In type III, R1 and R2 are both UV, and R3 and R4 are green receptors. The double-peaked blue, and green receptors with depressed sensitivity in the violet in type II ommatidia have depressed sensitivity at 420 nm, which is probably due to the filtering effect of a fluorescing material present in the type II ommatidia. Spectral heterogeneity of ommatidia seems to be a common design of insect compound eyes.

[Differentiated microcarcinoma of the thyroid gland in 45 cases]

OBJECTIVE

To offer therapeutic management for patients with microcarcinoma of the thyroid gland (TMC).

METHOD

Forty-five patients with TMC were treated from 1993, including 10 males and 35 females. Homolateral total thyroidectomy + contralateral subtotal thyroidectomy + homolateral functional neck dissection was taken as routine.

RESULT

Among 168 patients with differentiated carcinoma of the thyroid gland, 45 patients were TMC (26.78%). Homolateral metastasis of lymph node presented in 11 (24.44%) of the TMC patients. No operation complications. All patients were followed up. No recurrence, no death.

CONCLUSION

The lymph node metastasis appears to be high. Homolateral total thyroidectomy + contralateral subtotal thyroidectomy + homolateral functional neck dissection was effective and essential.

Changes in serum leptin levels in chronic renal failure patients with metabolic acidosis

OBJECTIVE

To examine the relationship between serum leptin levels (SLL) and metabolic acidosis in patients with chronic renal failure (CRF).

DESIGN

SLL in control patients and in predialysis patients with CRF were measured and compared. SLL before and after correction of acidosis in patients with CRF were also compared.

PATIENTS AND CONTROLS

Twenty-five patients with CRF (10 men and 15 women) aged 51.2 +/- 10.4 years and control patients (healthy subjects, 23 men and 25 women) aged 42.1 +/- 12.6 years were studied.

INTERVENTION

Five percent sodium bicarbonate (NaHCO(3), 2 to 3 mL/kg) was intravenously infused on the morning of the first day of treatment. NaHCO(3) was taken orally at a dosage of 50 to 200 mg/kg/d for 3 to 5 days thereafter.

MAIN OUTCOME MEASURE

SLL before and after NaHCO(3) treatment was measured by radioimmunoassay, and blood gas was measured before and after correction of metabolic acidosis in patients with CRF.

RESULTS

SLL in the normal control group (n = 48) was 10.04 +/- 7.0 ng/mL and was realated to body mass index (BMI) (P =.0331). SLL in men (n = 23) was lower than that in female controls (n = 25, P <.01). SLL in patients with CRF (n = 25) before (plasma HCO(3)(-), 13.03 +/- 3.05 mmol/L) and immediately after improvement of metabolic acidosis (plasma HCO(3)(-), 18.35 +/- 4.21 mmol/L) was 14.52 +/- 9.27 ng/mL and 15.34 +/- 11.89 ng/mL (P >.05), respectively. SLL measured 3 to 5 days after treatment for metabolic acidosis (plasma HCO(3)(-), 20.46 +/- 4.03 mmol/L) was 19.33 +/- 14.58 ng/mL, which was significantly higher than that in the normal control group and that in acidotic patients before NaHCO(3) treatment (P <.01).

CONCLUSIONS

SLL in acidotic patients with CRF were comparable to that in control subjects, and SLL was significantly increased after correction of metabolic acidosis in patients with CRF. The preliminary results suggest that hyperleptinemia in patients with CRF may be masked by metabolic acidosis and that metabolic acidosis may inhibit leptin synthesis or secretion. Further studies are needed to clarify the mechanisms.

Crystal structure of Staphylococcus aureus tyrosyl-tRNA synthetase in complex with a class of potent and specific inhibitors

SB-219383 and its analogues are a class of potent and specific inhibitors of bacterial tyrosyl-tRNA synthetases. Crystal structures of these inhibitors have been solved in complex with the tyrosyl-tRNA synthetase from Staphylococcus aureus, the bacterium that is largely responsible for hospital-acquired infections. The full-length enzyme yielded crystals that diffracted to 2.8 A resolution, but a truncated version of the enzyme allowed the resolution to be extended to 2.2 A. These inhibitors not only occupy the known substrate binding sites in unique ways, but also reveal a butyl binding pocket. It was reported that the Bacillus stearothermophilus TyrRS T51P mutant has much increased catalytic activity. The S. aureus enzyme happens to have a proline at position 51. Therefore, our structures may contribute to the understanding of the catalytic mechanism and provide the structural basis for designing novel antimicrobial agents.

Simultaneous recovery of RNA and DNA from soils and sediments

Recovery of mRNA from environmental samples for measurement of in situ metabolic activities is a significant challenge. A robust, simple, rapid, and effective method was developed for simultaneous recovery of both RNA and DNA from soils of diverse composition by adapting our previous grinding-based cell lysis method (Zhou et al., Appl. Environ. Microbiol. 62:316-322, 1996) for DNA extraction. One of the key differences is that the samples are ground in a denaturing solution at a temperature below 0 degrees C to inactivate nuclease activity. Two different methods were evaluated for separating RNA from DNA. Among the methods examined for RNA purification, anion exchange resin gave the best results in terms of RNA integrity, yield, and purity. With the optimized protocol, intact RNA and high-molecular-weight DNA were simultaneously recovered from 19 soil and stream sediment samples of diverse composition. The RNA yield from these samples ranged from 1.4 to 56 microg g of soil(-1) dry weight), whereas the DNA yield ranged from 23 to 435 microg g(-1). In addition, studies with the same soil sample showed that the DNA yield was, on average, 40% higher than that in our previous procedure and 68% higher than that in a commercial bead milling method. For the majority of the samples, the DNA and RNA recovered were of sufficient purity for nuclease digestion, microarray hybridization, and PCR or reverse transcription-PCR amplification.

Inhibitors of bacterial enoyl acyl carrier protein reductase (FabI): 2,9-disubstituted 1,2,3,4-tetrahydropyrido[3,4-b]indoles as potential antibacterial agents

An SAR study of a screening lead has led to the identification of 2,9-disubstituted 1,2,3,4-tetrahydropyrido[3,4-b]indoles as inhibitors of Staphylococcus aureus enoyl acyl carrier protein reductase (FabI).

Seven human immunodeficiency virus (HIV) antigen-antibody combination assays: evaluation of HIV seroconversion sensitivity and subtype detection

In this study, we evaluated the performance of two prototype human immunodeficiency virus (HIV) antigen-antibody (Ag-Ab) combination assays, one from Abbott Laboratories (AxSYM HIV Ag-Ab) and the other from bioMerieux (VIDAS HIV Duo Ultra), versus five combination assays commercially available in Europe. The assays were Enzygnost HIV Integral, Genscreen Plus HIV Ag-Ab, Murex HIV Ag-Ab Combination, VIDAS HIV Duo, and Vironostika HIV Uniform II Ag-Ab. All assays were evaluated for the ability to detect p24 antigen from HIV-1 groups M and O, antibody-positive plasma samples from HIV-1 groups M and O, HIV-2, and 19 HIV seroconversion panels. Results indicate that although all combination assays can detect antibodies to HIV-1, group M, subtypes A to G, circulating recombinant form (CRF) A/E, and HIV-1 group O, their sensitivity varied considerably when tested using diluted HIV-1 group O and HIV-2 antibody-positive samples. Among combination assays, the AxSYM, Murex, and VIDAS HIV Duo Ultra assays exhibited the best antigen sensitivity (at approximately 25 pg of HIV Ag/ml) for detection of HIV-1 group M, subtypes A to G and CRF A/E, and HIV-1 group O isolates. However, the VIDAS HIV Duo Ultra assay had a lower sensitivity for HIV-1 group M and subtype C, and was unable to detect subtype C antigen even at 125 pg of HIV Ag/ml. The HIV antigen sensitivity of the VIDAS HIV Duo and Genscreen Plus combination assays was approximately 125 pg of HIV Ag/ml for detection of all HIV-1 group M isolates except HIV-1 group O while the sensitivity of Vironostika HIV Uniform II Ag-Ab and Enzygnost HIV Integral Ag-Ab assays for all the group M subtypes was >125 pg of HIV Ag/ml. Among the combination assays, the AxSYM assay had the best performance for detection of early seroconversion samples, followed by the Murex and VIDAS HIV Duo Ultra assays.

[Study on the quality standards for xianghe suppository]

The quality standards for Xianghe suppository were studied. The TLC methods for identification of Rhizoma Coptidis, Radix Sophorae Flavescentis and Flos Caryophylli were established. A simple high performance liquid chromatographic method was established for determination of berberine and palmatine. The mobile phase was acetonitrile-water(1:1, containing KH2PO4 3.4 g, CH3(CH2)11 SO4Na 1.7 g per 1000 ml). UV detecting wavelength was 345 nm. This method is suitable for the quality control of Xianghe suppository.

Identification of a Delta 4 fatty acid desaturase from Thraustochytrium sp. involved in the biosynthesis of docosahexanoic acid by heterologous expression in Saccharomyces cerevisiae and Brassica juncea

The existence of Delta 4 fatty acid desaturation in the biosynthesis of docosahexanoic acid (DHA) has been questioned over the years. In this report we describe the identification from Thraustochytrium sp. of two cDNAs, Fad4 and Fad5, coding for Delta 4 and Delta 5 fatty acid desaturases, respectively. The Delta 4 desaturase, when expressed in Saccharomyces cerevisiae, introduced a double bond at position 4 of 22:5(n-3) and 22:4(n-6) resulting in the production of DHA and docosapentanoic acid. The enzyme, when expressed in Brassica juncea under the control of a constitutive promoter, desaturated the exogenously supplied substrate 22:5(n-3), resulting in the production of DHA in vegetative tissues. These results support the notion that DHA can be synthesized via Delta 4 desaturation and suggest the possibility that DHA can be produced in oilseed crops on a large scale.

1,4-Disubstituted imidazoles are potential antibacterial agents functioning as inhibitors of enoyl acyl carrier protein reductase (FabI)

1,4-Disubstituted imidazole inhibitors of Staphylococcus aureus and Escherichia coli enoyl acyl carrier protein reductase (FabI) have been identified. Crystal structure data shows the inhibitor 1 bound in the enzyme active site of E. coli FabI.

Dynamic process of apoptosis in adult rat cardiomyocytes analyzed using 48-hour videomicroscopy and electron microscopy: beating and rate are associated with the apoptotic process

Dynamic process of apoptosis has not been elucidated in adult rat cardiomyocytes. Soluble Fas ligand (0.1 microg/ml) in the presence of actinomycin D (0.05 microg/ml) induced apoptosis in cultured adult rat cardiomyocytes, as documented by activated caspase-3, DNA fragmentation, and apoptotic ultrastructure. In the present model, we observed 60 adult cardiomyocytes with a normal rod shape under a real-time videomicroscope continuously for 48 hours. Seventeen cells (28%) were unchanged and 7 cells (12%) showed oncosis (so-called necrosis) in which no beating was evident. In the remaining 36 cells (apoptosis, 60%), a slow beating (17 +/- 3/min) was initiated 16 +/- 1 hours later. Approximately 1 hour later, the rod cells showed long-axial shortening as bone- or club-like, or square-shaped, accompanied with faster beating rates (35 +/- 7/min). In 29 cells (type A1 and A2), marked shrinkage occurred; the cellular shape became almost completely round with a smooth surface and the beating ceased 3.0 +/- 0.4 hours later. Then, smooth budding appeared 0.6 +/- 0.2 hours later. Apoptotic bodies were found in 8 cells 10 +/- 4 hours later (type A1, 13%) but not in 21 cells (type A2, 35%). In the other 7 cells (type A3, 12%), the cell surface became rough 8 +/- 3 hours later and the beating ceased. Maximal beating rate was greatest in type A1 (72 +/- 26/min) and greater in type A2 (29 +/- 5/min) than in type A3 (10 +/- 2/min). Electron microscopy confirmed apoptotic ultrastructure even in the cardiomyocytes with bone-, club-like, or square shapes, suggesting that type A3 as well as A1 and A2 is also under apoptotic process. A caspase inhibitor, zVAD.fmk, blocked beating, apoptotic morphology, and DNA fragmentation, indicating these depended on caspase activation. In the caspase-dependent apoptotic process of cultured adult cardiomyocytes, beating and the following deformity of the cellular edges were the initial signs and the rate of beating was related with the subsequent three different processes of apoptosis.

Carboxyl-methylation of Rab3D in the rat pancreatic acinar tumor cell line AR42J

Rab3D is a small GTPase implicated in regulated exocytosis, and is a marker of secretory granules in exocrine cells. We have previously shown that rab3D undergoes reversible carboxyl-methylation in adult rat pancreatic acinar cells, and that carboxyl-methylation of rab3D is developmentally regulated concomitantly with the maturation of the regulated secretory apparatus in rat pancreas. We also observed that dexamethasone treatment of the rat pancreatic acinar tumor cell line, AR42J, led to a significant increase in the size of the unmethylated pool of a rab3-like protein. The current study was designed to further characterize this rab3-like protein. Here we show that AR42J cells express rab3D, and that the protein focuses on 2D gels as two spots with pI values of 4.9 and 5.0. Treatment of AR42J cells with N-acetyl-S-geranylgeranyl-l-cysteine, an inhibitor of carboxyl-methylation, led to a decrease in the basic form of rab3D and a proportional increase in the acidic form. In contrast, N-acetyl-S-farnesyl-l-cysteine, which inhibits carboxyl-methylation of farnesylated proteins, had no effect. Lovastatin, an inhibitor of geranylgeranylation, also induced an accumulation of the acidic form of rab3D. Taken together, these data indicate that rab3D can undergo reversible carboxyl-methylation in AR42J cells by a geranylgeranyl-specific methyltransferase. The 2D gel and immunoblotting analyses indicated that dexamethasone treatment of AR42J cells led to an increase in the proportion of the unmethylated form of rab3D concurrent to inducing a regulated secretory pathway, similar to the rab3D profile change in developing rat pancreas. Our data, along with previous studies done on developing rat pancreas, indicate that the tumor cell line AR42J represents a good model system for studying the regulated secretory pathway, and that carboxyl-methylation of rab3D may play a role in the acquisition of stimulus-secretion coupling.

[Effects of processing on antioxidation of Radix et Rhizoma Rhei and Rhizoma Polygoni Cuspidati]

OBJECTIVE

To investigate the effects of Processing on antioxidation of Radix et Rhizoma Rhei and Rhizoma Polygoni Cuspidati.

METHOD

The oxygen free radicals generation system and mouse liver homogenate lipid peroxidation in vitro were used.

RESULT

The processed products of Radix et Rhizoma Rhei and Rhizoma Polygoni Cuspidati could scavenge superoxide radical (O2-.) generated through hypoxanthine-oxidase system and (.OH) generated through Fenton action, and inhibit lipid peroxidation induced by hydroxyl radical generation system, respectively. There existed significant differences among the different processed products.

CONCLUSION

After Radix et Rhizoma Rhei and Rhizoma Polygoni Cuspidati were processed, their effects became weaker.

A study of time-domain FXLMS algorithms with control output constraint

A single input, single output active noise control system using the time-domain Filtered-X LMS algorithm with output constraint is investigated. The constraint on the output of the control filter is applied by three different methods: the leakage algorithm based on the transformation method using a penalty function; the re-scaling algorithm based on the active set method; and the simple practical (clipping) algorithm which just clips the output if a constraint is encountered. A comparison of the three algorithms shows that the re-scaling algorithm can usually work successfully under the constraint, while the leakage algorithm usually needs a large leakage coefficient to satisfy the constraint with a resulting performance loss. The clipping algorithm has potential problems both with the stability and convergence speed.

Gallic acid induces vascular smooth muscle cell death via hydroxyl radical production

In the present study, we investigated whether gallic acid (GA) can induce death in cultured vascular smooth muscle cells (VSMCs), and whether production of the hydroxyl radical (.OH) is involved in the process of GA action. GA killed cultured VSMCs from rat aorta, in a dosc- and time-dependent manner. Cytoplasmic shrinkage and nuclear condensation were observed light microscopically in GA-treated VSMCs, which appeared apoptotic. However, the ultrastructure of the VSMC was not typical of apoptosis: nuclear condensation was not glossy, and the plasma membrane and subccellular organelles were disrupted. Although the VSMC were positive for in situ nick end-labeling (TUNEL). they did not show a DNA ladder pattern on gel electrophoresis and were negative for T aq polymerase-based in situ ligation, which is more specific for apoptosis than TUNEL. Moreover. GA-induced cell death was not prevented by Boc-Asp-fmk (a pan-caspase inhibitor). Production of OH was detected in GA-treated VSMCs using high-performance liquid chromatography with salicylic acid as a trapping agent. Lipid peroxidation was also observed. The production of .OH was inhibited by catalase (CAT) and deferoxamine (DFX), and these treatments completely rescued VSMCs from cell death. In a cell-free system, GA produced .OH in the presence of Fe2+-EDTA, which was quenched by CAT and DFX, suggesting involvement of the Haber-Weiss reaction. Oxidative stress by reactive oxygen species, .OH in particular, is one of the mechanisms of GA-induced death of VSMCs, the mode of which was different from typical apoptosis.

Refined structures of beta-ketoacyl-acyl carrier protein synthase III

beta-Ketoacyl-acyl carrier protein synthase III (FabH) is a condensing enzyme that plays central roles in fatty acid biosynthesis. Three-dimensional structures of E. coli FabH in the presence and absence of ligands have been refined to 1.46 A resolution. The structures of improved accuracy revealed detailed interactions involved in ligand binding. These structures also provided new insights into the FabH mechanism, e.g. the possible role of a water or hydroxyl anion in Cys112 deprotonation. A structure of the apo enzyme uncovered large conformational changes in the active site, exemplified by the disordering of four essential loops (84-86, 146-152, 185-217 and 305-307) and the movement of catalytic residues (Cys112 and His244). The disordering of the loops leads to greater than 50 % reduction in the FabH dimer interface, suggesting a dynamic nature for an unusually large portion of the dimer interface. The existence of a large solvent-accessible channel in the dimer interface as well as two cis-peptides (cis-Pro88 and cis-Phe308) in two of the disordered loops may explain the observed structural instabilities.

Two point mutations in mitochondrial DNA of cytochrome c oxidase coexist with normal mtDNA in a patient with Alzheimer's disease

The mitochondrial cytochrome c oxidase (CO) gene sequence was determined on a patient with Alzheimer's disease (AD). Compared to the standard Cambridge sequence to identify base changes,two missense mutations were found in the patient with AD. The mutations were a G to T transition at np 8206 and an A to T transition at np 8224. The np 8206 mutation changed a Met to an Ile and np 8224 mutation changed a Leu to a Phe. The normal bases and the mutations of mitochondrial DNA (mtDNA) coexist in the patient. Further studies will be required to demonstrate the role of the point mutations of mitochondrial DNA in the pathogenesis of Alzheimer's disease.

Complex HLA-DR and -DQ interactions confer risk of narcolepsy-cataplexy in three ethnic groups

Human narcolepsy-cataplexy, a sleep disorder associated with a centrally mediated hypocretin (orexin) deficiency, is tightly associated with HLA-DQB1*0602. Few studies have investigated the influence that additional HLA class II alleles have on susceptibility to this disease. In this work, 1,087 control subjects and 420 narcoleptic subjects with cataplexy, from three ethnic groups, were HLA typed, and the effects of HLA-DRB1, -DQA1, and -DQB1 were analyzed. As reported elsewhere, almost all narcoleptic subjects were positive for both HLA-DQA1*0102 and -DQB1*0602. A strong predisposing effect was observed in DQB1*0602 homozygotes, across all ethnic groups. Relative risks for narcolepsy were next calculated for heterozygous DQB1*0602/other HLA class II allelic combinations. Nine HLA class II alleles carried in trans with DQB1*0602 were found to influence disease predisposition. Significantly higher relative risks were observed for heterozygote combinations including DQB1*0301, DQA1*06, DRB1*04, DRB1*08, DRB1*11, and DRB1*12. Three alleles-DQB1*0601, DQB1*0501, and DQA1*01 (non-DQA1*0102)-were found to be protective. The genetic contribution of HLA-DQ to narcolepsy susceptibility was also estimated by use of lambda statistics. Results indicate that complex HLA-DR and -DQ interactions contribute to the genetic predisposition to human narcolepsy but that additional susceptibility loci are also most likely involved. Together with the recent hypocretin discoveries, these findings are consistent with an immunologically mediated destruction of hypocretin-containing cells in human narcolepsy-cataplexy.