Effects of nurse managers' inclusive leadership on nurses' psychological safety and innovative work behavior: The moderating role of collectivism.

INTRODUCTION: In the rapidly evolving healthcare landscape, the capacity to foster innovative work behavior among nurses is increasingly important. This study examined the dynamics between inclusive leadership, psychological safety, collectivism, and innovative work behavior among nurses. DESIGN: The study used a cross-sectional, correlational design. METHODS: This study utilized data from 730 medical-surgical nurses who provided direct care to patients. Standardized instruments were used to assess key study variables. Statistical analyses, including moderated mediation regressions, were employed to investigate the complex interplay among these variables. RESULTS: We found a positive association between inclusive leadership and innovative work behavior, and psychological safety mediated this relationship. Collectivism moderated inclusive leadership's direct relationship with psychological safety and its indirect relationship with innovative work behavior. The results revealed that nurses with lower levels of collectivism were more responsive to their managers' inclusive behaviors, strengthening the relation between inclusive leadership, psychological safety, and innovative work behavior. CONCLUSION: Our findings suggest that promoting inclusive leadership behaviors among nurse managers to create a psychologically safe environment can motivate nurses to engage in innovative work behavior. However, it is also important to understand that the effectiveness of leadership may differ depending on the collectivist values of individual nurses. CLINICAL RELEVANCE: Nurse managers should adopt inclusive leadership behaviors, such as valuing trust, open communication, and diversity, in order to foster psychological safety and innovative work behavior among nurses.

Diagnostic utility of skin autofluorescence when patch test results are doubtful.

BACKGROUND: The standard diagnostic test for allergic contact dermatitis is the patch test, which can also be used to identify irritant contact dermatitis. Doubtful reactions (?+) can be often clinically relevant to individuals and can require additional tests. OBJECTIVES: The purpose of this study was to examine whether autofluorescence (AF) measurements in patients with doubtful reactions are helpful in diagnosing contact dermatitis. METHODS: Patients with a history of contact dermatitis were patch tested on the upper back for 48-hours of occlusion using aqueous solutions of 5% sodium lauryl sulfate. Reaction intensity was scored, and AF was measured on reactive lesions and non-lesions. Three dermatologists classified the results as positive or negative using the fluorescence photographs of patients with a doubtful reaction. RESULTS: Among doubtful reactions, the R/G% values were significantly higher in the AF- based positive group than in the negative group (P = .0086). On the other hand, the heterogeneity values of R, G, and B (HR, HG, HB) were significantly lower in the AF-based positive group (P = .0026, .0046, .0004 respectively). CONCLUSIONS: Measuring AF along with the clinical readings can help confirm doubtful patch test reactions.

Detection of admittivity anomaly on high-contrast heterogeneous backgrounds using frequency difference EIT.

This paper describes a multiple background subtraction method in frequency difference electrical impedance tomography (fdEIT) to detect an admittivity anomaly from a high-contrast background conductivity distribution. The proposed method expands the use of the conventional weighted frequency difference EIT method, which has been used limitedly to detect admittivity anomalies in a roughly homogeneous background. The proposed method can be viewed as multiple weighted difference imaging in fdEIT. Although the spatial resolutions of the output images by fdEIT are very low due to the inherent ill-posedness, numerical simulations and phantom experiments of the proposed method demonstrate its feasibility to detect anomalies. It has potential application in stroke detection in a head model, which is highly heterogeneous due to the skull.

First Report of Bean common mosaic virus in Cudrania tricuspidata in Korea.

Cudrania tricuspidata (Moraceae) is a deciduous tree widely distributed in East Asia, including China, Korea, and Japan. It produces delicious fruit, and its cortex and root bark have been used as a traditional medicine to treat neuritis and inflammation. As C. tricuspidata has become known as a functional food, its cultivation area and production gradually have increased in Korea. However, information of viral disease in C. tricuspidata is very limited. In September 2012, open-field-grown C. tricuspidata trees showing virus-like symptoms of mosaic, yellowing, and distortion on the leaves were found in Naju, Korea. The fruit production in the diseased trees decreased to 20 to 40% of that in healthy trees. To identify causal agent(s), total RNA was isolated from the symptomatic leaves and used to generate a transcriptome library using the TruSeq Stranded Total RNA with Ribo-Zero Plant kit (Illumina, San Diego, CA) according to the manufacturer's instruction. The transcriptome library was analyzed by next-generation sequencing (NGS) using an Illumina HiSeq2000 sequencer. NGS reads were quality filtered and de novo assembled by the Trinity pipeline, and the assembled contigs were analyzed against the viral reference genome database in Genbank by BLASTn and BLASTx searches (3). The entire NGS procedure was perofrmed by Macrogen Inc. (Seoul, South Korea). Among the analyzed contigs, one large contig (10,043 bp) was of viral origin. Nucleotide blast searches showed that the contig has a maximum identity of 89% (with 100% coverage) to the isolate MS1 (Genbank Accession No. EU761198) of Bean common mosaic virus (BCMV), which was isolated from Macroptilium atropurpureum in Australia. The presence of BCMV was confirmed by a commercially available double-antibody sandwich (DAS)-ELISA kit (Agdia, Elkhart, IN). To confirm the BCMV sequence obtained by NGS, two large fragments covering the entire BCMV genome were amplified by reverse transcription-polymerase chain reaction (RT-PCR) using two sets of specific primers (5'-AAAATAAAACAACTCATAAAGACAAC-3' and 5'-AGACTGTGTCCCAGAGCATTTC-3' to amplify the 5' half of the BCMV genome; 5'-GCATCCTGAGATTCACAGAATTC-3' and 5'-GGAACAACAAACATTGCCGTAG-3' to amplify the 3' half of the BCMV genome) and sequenced. To obtain the complete genome sequence, the 5' and 3' terminal sequences were analyzed by the 5' and 3' rapid amplification of cDNA ends (RACE) method as described previously (1). The assembled full-length sequence of BCMV isolated from C. tricuspidata was 10,051 nucleotides in length without a poly(A) tail. It was deposited in Genbank under the accession number KM076650. BCMV, a member of the genus Potyvirus, is one of the most common viruses naturally infecting legumes, including Phaseolus vulgaris (2). In general, BCMV is known to have a restricted host range outside legume species (2). Therefore, the identification of BCMV from C. tricuspidata in this report is very exceptional. Because BCMV is easily transmitted by various aphids like other potyviruses, a large-scale survey may be required for exact investigation of the BCMV incidence in C. tricuspidata to prevent rapid spread of the virus. To the best of our knowledge, this is the first report of BCMV in C. tricuspidata. References: (1) H.-R. Kwak et al. Plant Pathol. J. 29:274, 2013. (2) M. Saiz et al. Virus Res. 31:39, 1994. (3) S.-E. Schelhorn et al. PLoS Comput. Biol. 9:e1003228, 2013.

First Report of Broad bean wilt virus 2 in Leonurus sibiricus in Korea.

Leonurus sibiricus L. (family Lamiaceae) has been used as a traditional herbal remedy to treat various gynecologic diseases. Although it is a widely distributed subtropical weed in Southeast Asia, L. sibiricus have been commercially cultivated on a small scale in many geographic areas of Korea. In August 2012, field-grown L. sibiricus plants showing mosaic, yellowing, and stunting symptoms were collected near a pepper field in Andong, Korea. Since L. sibiricus is only consumed as a raw material of traditional medicine in Korea, symptomatic plants lose commercial value entirely. To identify the causal agent(s) of the virus-like symptoms, total RNA was extracted from the symptomatic leaves, and a transcriptome library was generated using the TruSeq Stranded Total RNA with Ribo-Zero plant kit (Illumina, San Diego, CA) according to the standard protocol. Next-generation sequencing (NGS) was performed using an Illumina HiSeq2000 sequencer. De novo assembly of the quality filtered NGS reads (101-bp paired-end reads) were performed using the Trinity pipeline and the assembled contigs (92,329 contigs) were analyzed against the viral reference genome database in GenBank by BLASTn and BLASTx searches (3). The entire NGS procedure was performed by Macrogen Inc. (Seoul, South Korea). Among the analyzed contigs, only two large contigs were clearly of viral origin. Nucleotide blast searches showed that the first and second contigs (5,914 and 3,534 bp, respectively) have maximum identities of 91 and 95% to RNA1 of the isolate RP3 (GenBank Accession No. JX183225) and RNA2 of the isolate RP7 (JX183234) of Broad bean wilt virus 2 (BBWV-2), which were isolated from pepper in Korea. The NGS results were confirmed by analyzing the sequences of the fragments covering the entire BBWV-2 genome amplified by RT-PCR using specific primers for BBWV-2 as described previously (1). To obtain the complete genome sequence, terminal sequences of both RNA segments were analyzed by the 5' and 3' rapid amplification of cDNA ends (RACE) method as described previously (1). The assembled full-length sequences of BBWV-2 RNA1 and RNA2 isolated from L. sibiricus were 5,951 and 3,575 nucleotides in length, respectively, and deposited in GenBank under the accessions KM076648 and KM076649, respectively. BBWV-2 belongs to the genus Fabavirus in the family Secoviridae and it is known to have a wide host range. To investigate the host range of the BBWV-2 isolated from L. sibiricus, sap from the symptomatic leaves of L. sibiricus was inoculated to the test plants including Nicotiana benthamiana, Capsicum annuum (red pepper), and C. annuum var. gulosum (Paprika). RT-PCR detection and sequencing of the amplicons showed that all the inoculated test plants were infected with the BBWV-2 isolated from L. sibiricus. Currently, BBWV-2 is epidemic in pepper fields in Korea (1,2). Because BBWV-2 is easily transmitted by various aphids, and L. sibiricus is widely distributed in both wild and cultivated fields in Korea, this host might serve as a potential source of BBWV-2 to other crops such as pepper. To the best of our knowledge, this is the first report of BBWV-2 in L. sibiricus. References: (1) H.-R. Kwak et al. Plant Pathol. J. 29:274, 2013. (2) H.-R. Kwak et al. Plant Pathol. J. 29:397, 2013. (3) S.-E. Schelhorn et al. PLoS Comput. Biol. 9:e1003228, 2013.

EIT-based fabric pressure sensing.

This paper presents EIT-based fabric sensors that aim to provide a pressure mapping using the current carrying and voltage sensing electrodes attached to the boundary of the fabric patch. Pressure-induced shape change over the sensor area makes a change in the conductivity distribution which can be conveyed to the change of boundary current-voltage data. This boundary data is obtained through electrode measurements in EIT system. The corresponding inverse problem is to reconstruct the pressure and deformation map from the relationship between the applied current and the measured voltage on the fabric boundary. Taking advantage of EIT in providing dynamical images of conductivity changes due to pressure induced shape change, the pressure map can be estimated. In this paper, the EIT-based fabric sensor was presented for circular and rectangular sensor geometry. A stretch sensitive fabric was used in circular sensor with 16 electrodes and a pressure sensitive fabric was used in a rectangular sensor with 32 electrodes. A preliminary human test was carried out with the rectangular sensor for foot pressure mapping showing promising results.

Characterization of Cellulolytic and Xylanolytic Enzymes of Bacillus licheniformis JK7 Isolated from the Rumen of a Native Korean Goat.

A facultative bacterium producing cellulolytic and hemicellulolytic enzymes was isolated from the rumen of a native Korean goat. The bacterium was identified as a Bacillus licheniformis on the basis of biochemical and morphological characteristics and 16S rDNA sequences, and has been designated Bacillus licheniformis JK7. Endoglucanase activities were higher than those of ß-glucosidase and xylanase at all temperatures. Xylanase had the lowest activity among the three enzymes examined. The optimum temperature for the enzymes of Bacillus licheniformis JK7 was 70°C for endoglucanase (0.75 U/ml) and 50°C for ß-glucosidase and xylanase (0.63 U/ml, 0.44 U/ml, respectively). All three enzymes were stable at a temperature range of 20 to 50°C. At 50°C, endoglucanse, ß-glucosidase, and xylanase had 90.29, 94.80, and 88.69% residual activity, respectively. The optimal pH for the three enzymes was 5.0, at which their activity was 1.46, 1.10, and 1.08 U/ml, respectively. The activity of all three enzymes was stable in the pH range of 3.0 to 6.0. Endoglucanase activity was increased 113% by K(+), while K(+), Zn(+), and tween 20 enhanced ß-glucosidase activity. Xylanase showed considerable activity even in presence of selected chemical additives, with the exception of Mn(2+) and Cu(2+). The broad range of optimum temperatures (20 to 40°C) and the stability under acidic pH (4 to 6) suggest that the cellulolytic enzymes of Bacillus licheniformis JK7 may be good candidates for use in the biofuel industry.

Effects of synchronicity of carbohydrate and protein degradation on rumen fermentation characteristics and microbial protein synthesis.

A series of in vitro studies were carried out to determine i) the effects of enzyme and formaldehyde treatment on the degradation characteristics of carbohydrate and protein sources and on the synchronicity of these processes, and ii) the effects of synchronizing carbohydrate and protein supply on rumen fermentation and microbial protein synthesis (MPS) in in vitro experiments. Untreated corn (C) and enzyme-treated corn (EC) were combined with soy bean meal with (ES) and without (S) enzyme treatment or formaldehyde treatment (FS). Six experimental feeds (CS, CES, CFS, ECS, ECES and ECFS) with different synchrony indices were prepared. Highly synchronous diets had the greatest dry matter (DM) digestibility when untreated corn was used. However, the degree of synchronicity did not influence DM digestibility when EC was mixed with various soybean meals. At time points of 12 h and 24 h of incubation, EC-containing diets showed lower ammonia-N concentrations than those of C-containing diets, irrespective of the degree of synchronicity, indicating that more efficient utilization of ammonia-N for MPS was achieved by ruminal microorganisms when EC was offered as a carbohydrate source. Within C-containing treatments, the purine base concentration increased as the diets were more synchronized. This effect was not observed when EC was offered. There were significant effects on VFA concentration of both C and S treatments and their interactions. Similar to purine concentrations, total VFA production and individual VFA concentration in the groups containing EC as an energy source was higher than those of other groups (CS, CES and CFS). The results of the present study suggested that the availability of energy or the protein source are the most limiting factors for rumen fermentation and MPS, rather than the degree of synchronicity.

Effects of synchronization of carbohydrate and protein supply in total mixed ration with korean rice wine residue on ruminal fermentation, nitrogen metabolism and microbial protein synthesis in holstein steers.

Three Holstein steers in the growing phase, each with a ruminal cannula, were used to test the hypothesis that the synchronization of the hourly rate of carbohydrate and nitrogen (N) released in the rumen would increase the amount of retained nitrogen for growth and thus improve the efficiency of microbial protein synthesis (EMPS). In Experiment 1, in situ degradability coefficients of carbohydrate and N in feeds including Korean rice wine residue (RWR) were determined. In Experiment 2, three total mixed ration (TMR) diets having different rates of carbohydrate and N release in the rumen were formulated using the in situ degradability of the feeds. All diets were made to contain similar contents of crude protein (CP) and neutral detergent fiber (NDF) but varied in their hourly pattern of nutrient release. The synchrony index of the three TMRs was 0.51 (LS), 0.77 (MS) and 0.95 (HS), respectively. The diets were fed at a restricted level (2% of the animal's body weight) in a 3×3 Latin-square design. Synchronizing the hourly supply of energy and N in the rumen did not significantly alter the digestibility of dry matter, organic matter, crude protein, NDF or acid detergent fiber (ADF) (p>0.05). The ruminal NH3-N content of the LS group at three hours after feeding was significantly higher (p<0.05) than that of the other groups; however, the mean values of ruminal NH3-N, pH and VFA concentration among the three groups were not significantly different (p>0.05). In addition, the purine derivative (PD) excretion in urine and microbial-N production (MN) among the three groups were not significantly different (p>0.05). In conclusion, synchronizing dietary energy and N supply to the rumen did not have a major effect on nutrient digestion or microbial protein synthesis (MPS) in Holstein steers.

Structure-activity relationships of piscidin 4, a piscine antimicrobial peptide.

Piscidin 4, an antimicrobial peptide recently isolated from mast cells of hybrid striped bass (Morone chrysops female × Morone saxatilis male), is unusual in that it is twice as long (44 amino acids) as the typical members of the piscidin family. We previously showed that native piscidin 4 had a modified amino acid at position 20, but synthetic piscidin 4 (having an unmodified Trp at position 20) had similar potent activity against a number of both human and fish bacterial pathogens. In this study, the structure and membrane topology of synthetic piscidin 4 were examined using liposomes as model bilayers. Circular dichroism analyses revealed that it had a disordered structure in aqueous solution and folded to form a relatively weak α-helical structure in both membrane-mimetic trifluoroethanol solutions and liposome suspensions. Fluorescence data (piscidin 4 embedded in liposomes) and leakage experiments indicated that piscidin 4 interacted strongly with the hydrophobic part of the liposome. Binding of piscidin 4 to liposomes induced significant blue shifts of the emission spectra of the single Trp residue (Trp20). Quenching of Trp20 by water-soluble quencher (either acrylamide or I-) indicated that the fluorescence of Trp20 decreased more in the presence of liposomes than in buffer solution, thus revealing that Trp20 is less accessible to the quenchers in the presence of liposomes. The relative leakage abilities of piscidin 4 (1 µM) with liposomes were in the following order: DPPC (100%)≥EYPC (94%)>DPPC/DPPG (65%)>EYPC/EYPG (0%). This high activity against DPPC and EYPC liposomes was contrary to our data suggesting that piscidin 4 has a much weaker tendency to form an α-helix than other piscidins, such as piscidin 1. However, the structural similarity of protozoan membranes to EYPC liposomes might explain our discovery of the potent activity of piscidin 4 against the important skin/gill parasite ich (Ichthyophthirius multifiliis), but its negligible hemolytic activity against vertebrate membranes (hybrid striped bass or human erythrocytes). It also suggests that other conformation(s) in addition to the α-helix of this peptide may be responsible for its selective activity. This differential toxicity also suggests that piscidin 4 plays a significant role in the innate defense system of hybrid striped bass and may be capable of functioning extracellularly.

Effects of hydrolyzed yeast supplementation in calf starter on immune responses to vaccine challenge in neonatal calves.

The effects of hydrolyzed yeast supplementation on growth performance, health and immune-physiological parameters in neonatal calves challenged with vaccine were investigated. Twelve Holstein calves were started in the experiment at 2 ± 1 days of age and were studied for 35 days. Calves were randomly assigned to each of two dietary treatments, a control (CON) and hydrolyzed yeast (HY) group. The calves in the HY group received control calf starter supplemented with 0.2% HY. All calves were given calf starter ad libitum for 5 weeks starting in week 1. Calves were also given whole milk according to a step-down milking protocol. In order to induce immune responses, all calves were challenged with Hog cholera and Erysipelothrix insidiossa live vaccines by intramuscular injection at 3 weeks of age. Growth performance and feed intake were not affected by dietary treatment throughout the experimental period, except that the HY group had significantly higher (P < 0.05) milk intake than did the CON group at 3 weeks of age. Calves in the HY group showed significantly better (P < 0.05) fecal and health scores at 3 weeks compared to those in the control group. After vaccine challenge, neutropenia, lymphophilia and thrombocytopenia were observed in the CON group, but calves in the HY group did not show significant changes of leukocytes. The average concentration of serum haptoglobin in the HY group was significantly higher (P < 0.05) at 1 and 3 days post-vaccine challenge (DPVC) than that of CON group. Feeding HY supplemented calf starter resulted in a higher (P < 0.05) relative amount of bacterial and viral - specific IgA than in the CON group at 5 DPVC. Although the percentage of CD4+ T cells was significantly (P < 0.05) higher in the HY group than in the CON group at -2 DPVC, significant differences between groups after vaccine challenge was not observed during the experimental period. These results suggest that 0.2% HY supplementation in calf starter can improve the health status and immune-related serum protein production and affect blood cell composition in neonatal calves after vaccine challenge.

Expression, purification and structural characterization of recombinant hepcidin, an antimicrobial peptide identified in Japanese flounder, Paralichthys olivaceus.

The cysteine-rich peptide hepcidin is an antimicrobial peptide and iron transport regulator that has been found in vertebrates including birds, fish and mammals. To elucidate the structure and biological function of fish hepcidin, which is difficult to produce synthetically, we have cloned several plasmid constructs encoding hepcidin from Japanese flounder, Paralichthys olivaceus, and tested expression of recombinant peptides, each with an N-terminal hexahistidine (6xHis) tag, in inclusion bodies or the periplasmic space of Escherichia coli. Hepcidin expressed in inclusion bodies was reduced, and subsequently refolded using a dilution technique with a cysteine redox system. The oxidized His-hepcidin monomer was separated from protein multimers and mass spectrometry analysis showed that the peptide was of the predicted size and contained four disulfide bonds. Removal of the 6xHis tag was attempted using enzymatic cleavage by Factor Xa and tobacco etch virus (TEV) protease or chemical cleavage by hydroxylamine. The Factor Xa cleavage was unsuccessful and hydroxylamine cleavage resulted in aggregation of cleaved peptide. TEV protease cleavage was successful but immediately resulted in hexamer formation despite varying reaction conditions (redox, non-redox, pH, temperature, target protein concentration, type of buffer). However, the recombinant His-hepcidin fusion peptide monomer showed considerable antimicrobial activity. NMR-based studies showed that hepcidin contained a rare vicinal disulfide linkage at the top of a loop structure and a short beta-sheet structure encompassing residues 7-13 and 19-25 that is stabilized by three disulfide bonds.

Evidence of still-ongoing convergence evolution of the lactase persistence T-13910 alleles in humans.

A single-nucleotide variant, C/T(-13910), located 14 kb upstream of the lactase gene (LCT), has been shown to be completely correlated with lactase persistence (LP) in northern Europeans. Here, we analyzed the background of the alleles carrying the critical variant in 1,611 DNA samples from 37 populations. Our data show that the T(-13910) variant is found on two different, highly divergent haplotype backgrounds in the global populations. The first is the most common LP haplotype (LP H98) present in all populations analyzed, whereas the others (LP H8-H12), which originate from the same ancestral allelic haplotype, are found in geographically restricted populations living west of the Urals and north of the Caucasus. The global distribution pattern of LP T(-13910) H98 supports the Caucasian origin of this allele. Age estimates based on different mathematical models show that the common LP T(-13910) H98 allele (approximately 5,000-12,000 years old) is relatively older than the other geographically restricted LP alleles (approximately 1,400-3,000 years old). Our data about global allelic haplotypes of the lactose-tolerance variant imply that the T(-13910) allele has been independently introduced more than once and that there is a still-ongoing process of convergent evolution of the LP alleles in humans.

MR imaging of the brain in Wilson disease of childhood: findings before and after treatment with clinical correlation.

BACKGROUND AND PURPOSE: Although brain MR imaging findings in adult Wilson disease have been described in considerable detail, a paucity of information currently exists regarding brain MR imaging findings in pediatric Wilson disease. The purpose of this study was to analyze the brain MR imaging findings in Wilson disease of childhood at the initial stage and during follow-up after treatment and to correlate these observations with clinical response. METHODS: We evaluated 50 patients with pediatric Wilson disease. Fifty initial and 20 follow-up MR images from 15 patients following penicillamine treatment were analyzed retrospectively, and the data were correlated with clinical findings. RESULTS: Patients were categorized into 3 groups on the basis of initial MR imaging findings. Group I (n = 23) showed normal MR imaging findings. Group II (n = 15) was characterized by T1-weighted images with increased signal intensity in the globus pallidus (n = 15, 100%) followed by the putamen, midbrain, and caudate nucleus. Group III (n = 12) demonstrated T2-weighted images with increased signal intensity in the putamen (n = 10, 83%), followed by the caudate nucleus, globus pallidus, thalamus, midbrain, and pons. There was a significant difference in mean age, the presence of neurologic symptoms, and Child-Pugh classification among the 3 groups (P < .001). Following copper chelating therapy, the changes on follow-up MR imaging were strongly correlated with clinical response to treatment (P < .001). CONCLUSION: Brain MR imaging in children with Wilson disease can be categorized into distinct groups and demonstrated a significant correlation with clinical findings. Interval changes on follow-up MR imaging were also closely correlated with clinical findings and helpful in assessing the clinical response.

Structure-activity relationship of neuropeptide gamma derived from mammalian and fish.

This study of relationship between structure and biologic activity was performed using five neuropeptide gammas [NPgamma; mammalian-NPgamma (M-NPgamma), trout-NPgamma (T-NPgamma), goldfish-NPgamma (G-NPgamma), bowfin-NPgamma (B-NPgamma), and shark-NPgamma (S-NPgamma)]. Circular dichroism (CD) spectra showed that all peptides took random structure in buffer solution. In neutral and acidic liposomes, M-NPgamma, T-NPgamma, B-NPgamma, and S-NPgamma still adopted random structure, while G-NPgamma had an alpha-helical structure. The biologic activity of NPgammas has been estimated by their effects on the intestinal motility and arterial relaxation. The intestinal motility was investigated with rat duodenum (RD), carp intestine (CI), and guinea-pig ileum (GPI). The arterial relaxing effect was tested with guinea-pig aorta (GPA) and rat mesenteric artery (RMA). In RD, the order of potency compared with the EC50 value was M-NPgamma >> S-NPgamma >> B-NPgamma >> G-NPgamma >> T-NPgamma. G-NPgamma was the most contractile agent in CI. S-NPgamma was the most contractile agent in GPI. Using an arterial relaxing test, the order of potency was G-NPgamma >> T-NPgamma >> B-NPgamma >> S-NPgamma >> M-NPgamma in GPA, and all NPgammas remarkably reduced relaxing activity in RMA. Despite their structural similarities to NPgammas, G-NPgamma has high affinity to tachykinin receptor-binding sites in GPA and CI, indicating an alpha-helical structure may have a critical role for receptor binding. However, an alpha-helical structure does not play a critical role in recognizing receptor-binding sites in RD and GPI.

Mutation spectrum of the glucose-6-phosphatase gene and its implication in molecular diagnosis of Korean patients with glycogen storage disease type Ia.

Glycogen storage disease type Ia (GSD Ia; MIM 232200) is an autosomal recessive inherited metabolic disorder resulting from a deficiency of the microsomal glucose-6-phosphatase (G6Pase), the enzyme that catalyzes the terminal step in gluconeogenesis and glycogenolysis. Various mutations in the G6Pase gene (G6PC) have been found in patients with GSD Ia. To elucidate the spectrum of the G6PC gene mutations, 13 unrelated Korean patients with GSD Ia were analyzed. We were able to identify mutant alleles in all patients, including three known mutations (727G > T, G122D, and T255I) and two novel mutations (P178A and Y128X). The frequency of the 727G > T mutation in Korean patients with GSD Ia was 81% (21/26), which was slightly lower than that (86-92%) in Japanese but much higher than that (44.4%) in Taiwan Chinese. Except one, all patients were either homozygous (9/13) or compound heterozygous (3/13) for the 727G > T mutation; the only patient without the 727G > T mutation was a compound heterozygote for the G122D and Y128X mutations. Our findings suggest that a DNA-based test can be used as the initial diagnostic approach in Korean patients clinically suspected to have GSD Ia, thereby avoiding invasive liver biopsy.

Diffusion PDE-based denoising technique for magnetic resonance electrical impedance tomography.

Recent progress in magnetic resonance electrical impedance tomography (MREIT) research has shown that conductivity images with higher spatial resolution and accuracy are achievable. One of the most important remaining problems to be solved in MREIT before we can apply the technique to human subjects is how to reduce the amount of injection current. Since we use an MRI scanner to measure the induced magnetic flux density data subject to an injection current, the data is contaminated with random noise. In order to obtain enough signal-to-noise ratio (SNR), we need to inject a large amount of current into the subject. However, it is obvious that we must comply with the electrical safety regulations and this means that we should deal with noisy data having a low SNR due to the limited amount of injection current. Furthermore, in the developed reconstruction algorithms, the required numerical differentiations of the noisy data may result in deterioration of the reconstructed conductivity image leading to a loss of important information. We propose a PDE-based denoising technique that diminishes the degradation of reconstructed conductivity images due to the noise in measured data. The proposed PDE-based technique is advantageous in reducing the random noise while preserving useful features in MREIT.

Conductivity images of biological tissue phantoms using a 3.0 tesla MREIT system.

We present cross-sectional conductivity images of a biological tissue phantom obtained by using a 3.0 Tesla magnetic resonance electrical impedance tomography (MREIT) system. Inside the cylindrical phantom with 140 mm diameter and 140 mm height, biological tissues such as bovine tongue and liver, porcine muscle, and chicken breast were placed within an agar gelatin. Injecting current of 480 mA.ms into the tissue phantom, we measured the z-component B/sub z/ of the induced magnetic flux density B=(B/sub x/, B/sub y/, B/sub z/). Using the harmonic B/sub z/ algorithm, we reconstructed cross-sectional conductivity images from the measured B/sub z/ data. Reconstructed images clearly distinguish different tissues in terms of both their shapes and conductivity values.