[Usefulness of Post-processing Scatter Correction in Portable Abdominal Radiography Using a Low Ratio Anti-scatter Grid].

Objectives: The aim of this study was to evaluate an influence of post-processing scatter correction in portable abdominal radiography using a low ratio anti-scatter grid (grid).

Methods: To assess tube voltage on portable abdominal radiography, a burger phantom was used to measure for inverse of image quality figure (IQF). For evaluation of the influence on using or not the grid, IQF were measured.

Marked thrombocytopenia in a neonate is associated with anti-HPA-5b, anti-HLA-A31, and anti-HLA-B55 antibodies.

Maternal antibodies against human platelet antigen (HPA) and/or human leukocyte antigen (HLA) cause fetal and neonatal alloimmune thrombocytopenia (FNAIT) in 0.09-0.15% of live births.

[Examination for Effectiveness of Scatter Correction in Portable Chest Radiography].

Objectives: The aim of this study was to evaluate the effectiveness of scatter correction in the portable chest radiography.

Methods: Digital radiographies were performed without anti-scatter grid (grid), with the scatter correction and with the grid ratio of 3 : 1 in this study. The scatter fraction and the detectability of low contrast signals were measured using the four acrylic phantoms of different thicknesses.

Iodine status of pregnant and postpartum Japanese women: effect of iodine intake on maternal and neonatal thyroid function in an iodine-sufficient area.

Background: Iodine deficiency in pregnant and lactating women results in serious damage to their fetuses, newborns, and weaning infants. The effect of dietary iodine intake on maternal and infantile thyroid function has not been well studied in iodine-sufficient areas, and there are few data on appropriate gestational age-specific reference ranges for urinary iodine excretion during pregnancy and lactation.

Objectives: The aim of the study was to characterize the gestational change of urinary iodine excretion in Japanese women and to assess the effects of iodine status on thyroid function in mother and infant.

Selective isolation of N-terminal peptides from proteins and their de novo sequencing by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry without regard to unblocking or blocking of N-terminal amino acids.

We have developed a new method to determine the N-terminal amino acid sequences of proteins, regardless of whether their N-termini are modified. This method consists of the following five steps: (1) reduction, S-alkylation and guanidination for targeted proteins; (2) coupling of sulfo-NHS-SS-biotin to N(alpha)-amino groups of proteins; (3) digestion of the modified proteins by an appropriate protease followed by oxidation with performic acid; (4) specific isolation of N-terminal peptides from digests using DITC resins; (5) de novo sequence analysis of the N-terminal peptides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) using the CAF (chemically assisted fragmentation) method or tandem mass spectrometric (MS/MS) analysis according to unblocked or blocked peptides, respectively. By employing DITC resins instead of avidin resins used in our previous method (Yamaguchi et al.

A simple and highly successful C-terminal sequence analysis of proteins by mass spectrometry.

A simple and efficient method for C-terminal sequencing of proteins has long been pursued because it would provide substantial information for identifying the covalent structure, including post-translational modifications. However, there are still significant impediments to both direct sequencing from C termini of proteins and specific isolation of C-terminal peptides from proteins. We describe here a highly successful, de novo C-terminal sequencing method of proteins by employing succinimidyloxycarbonylmethyl tris (2,4,6-trimethoxyphenyl) phosphonium bromide and mass spectrometry.

Terminal proteomics: N- and C-terminal analyses for high-fidelity identification of proteins using MS.

In proteomics, MS plays an essential role in identifying and quantifying proteins. To characterize mature target proteins from living cells, candidate proteins are often analyzed with PMF and MS/MS ion search methods in combination with computational search routines based on bioinformatics. In contrast to shotgun proteomics, which is widely used to identify proteins, proteomics based on the analysis of N- and C-terminal amino acid sequences (terminal proteomics) should render higher fidelity results because of the high information content of terminal sequence and potentially high throughput of the method not requiring very high sequence coverage to be achieved by extensive sequencing.

Specific isolation of N-terminal fragments from proteins and their high-fidelity de novo sequencing.

A new method to determine N-terminal amino acid sequences of multiple proteins at low pmol level by a parallel processing has been developed. The method contains the following five steps: (1) reduction, S-alkylation and guanidination for targeted proteins; (2) coupling with sulfosucccimidyl-2-(biotinamido)ethyl-1,3-dithiopropionate(sulfo-NHS-SS-biotin) to N(alpha)-amino groups of proteins; (3) digestion of the modified proteins by an appropriate protease; (4) specific isolation of N-terminal fragments of proteins by affinity capture using the biotin-avidin system; (5) de novo sequence analysis of peptides by MALDI-TOF-/MALDI-TOF-PSD mass spectrometry with effective utilization of the CAF (chemically assisted fragmentation) method.1 This method is also effective for N-terminal sequencing of each protein in a mixture of several proteins, and for sequencing components of a multiprotein complex.

Simultaneous detection of N-terminal fragment ions in a protein mixture using a ruthenium(II) complex.

Use of a bis(terpyridine)ruthenium(II) derivative as an N-terminal labeling reagent resulted in the simultaneous detection and individual determination of all the N-terminal fragments of the proteins in a mixture without requiring any separation. All of the N-termini of the guanidinated proteins were labeled selectively by the ruthenium complex (-CO-labeling). After chymotryptic digestion, the fragments were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and post-source decay (PSD).

High sequence-coverage detection of proteolytic peptides using a bis(terpyridine)ruthenium(II) complex.

The use of a bis(terpyridine)ruthenium(ii) complex for peptide labeling (Ru-CO labeling) supplied high intensity peaks in mass spectrometry (MS) analysis that overcame the contribution of protonation or sodiated adduction to peptides. Ru-CO-labeled insulin A- and B-chains were detected simultaneously in comparable peak abundance by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The mass spectra of chymotryptic peptide fragments of Ru-CO-labeled insulin also simultaneously indicated both N-terminal fragment ions, and amino acid sequences were determined easily by matrix-assisted laser desorption/ionization post-source-decay (MALDI-PSD).

Enhancement of MALDI-MS spectra of C-terminal peptides by the modification of proteins via an active ester generated in situ from an oxazolone.

For selective C-terminal derivatization of peptides and proteins, we have devised a method for activating the C-terminal carboxyl group by extending the oxazolone chemistry. A mixture of formic acid and acetic anhydride was found to be effective for the formation of an oxazolone, which was converted to an active ester in situ in the presence of a phenol or an N-hydroxide. In particular, the resulting active ester with pentafluorophenol facilitated the subsequent reaction with an amine and the hydrazine derivative to yield the C-terminal amide and hydrazide, respectively.

High-throughput method for N-terminal sequencing of proteins by MALDI mass spectrometry.

A high-throughput method for sequencing of N termini of proteins by using postsource decay (PSD) of matrix-assisted laser desorption/ionization mass spectrometry has been developed. After a protein blotted on the PVDF membrane was successively reduced, S-alkylated, and guanidinated, its N-amino group was coupled to biotinylcysteic acid. The protein was then extracted from the membrane and digested with trypsin.

Rapid and sensitive amino-acid sequencing of cloning Thermus thermophilus HB8 ferredoxin by proteomics.

Recombinant holo Thermus thermophilus [7Fe-8S] ferredoxin was synthesized by cloning from Thermus thermophilus HB8 gene. A specific sequence (Pro-His-Val-Ile) at the N-terminus of the recombinant ferredoxin was determined by a rapid and highly sensitive mass spectral method using a novel Ru(II) Edman reagent, [(tpy)Ru(tpy-C6H4-NCS)](PF6)2 (tpy=terpyridine). The formation of the recombinant holoTtFd was established by the characteristic absorptions and CD extrema as [7Fe-8S] ferredoxin.

Characterization of the cDNA encoding bullfrog, Rana catesbeiana, osteocalcin and two forms of the protein isolated from bone.

A full-length cDNA clone encoding osteocalcin from the bullfrog, Rana catesbeiana (bone Gla-protein, BGP) has been isolated, and the complete coding sequence for the 100-amino-acid pre-pro-osteocalcin protein was determined. The amino acid sequence of Rana catesbeiana osteocalcin, especially the mature 49-amino acid sequence, is closer to the mammalian than to the fish, Sparus osteocalcin. Rana mature osteocalcin has a similarity of 67% with human or 59% with rat osteocalcin, and only 42% with fish mature osteocalcin.

Enhanced responses in matrix-assisted laser desorption/ionization mass spectrometry of peptides derivatized with arginine via a C-terminal oxazolone.

We have developed a novel method for enhancing the response of a peptide in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) by activating the C-terminal carboxyl group through an oxazolone with which is coupled an amine containing a functional group to help ionize the peptide. The reactions consist of dehydration with acetic anhydride to give an oxazolone, followed by aminolysis with an appropriate amino acid derivative such as arginine methyl ester. The MALDI signal of Ac-Tyr-Gly-Gly-Phe-Leu-Arg-OMe, thus converted from leucine-enkephalin, was detected while completely excluding the responses of arginine-deficient peptides coexisting in the reaction mixture.