Improvement of sensitivity in HLA-DRB1 typing by semi-nested PCR-RFLP

A sensitive method of HLA-DRB1 typing was devised using a semi-nested polymerase chain reaction (PCR) followed by a restriction fragment length polymorphism (RFLP) analysis (semi-nested PCR-RFLP method). The first-round amplification (30 cycles) of the semi-nested PCR was performed using DRB generic primer pairs and the second round of PCRs (20 cycles) were performed using DRB1 group-specific primers. The products of the second round PCRs were digested with restriction endonucleases for the typing of HLA-DRB1 alleles. By this method, HLA-DRB1 typing was possible from 10 pg of genomic DNA extracted from lymphocytes and from 0.5 microliter of 1,000 times diluted blood without DNA extraction. HLA-DRB1 alleles could be typed from a 2-mm long bloodstained cotton thread prepared from 10 times diluted blood and from a 2-mm thread of whole blood bloodstains stored at room temperature for 2 years. From the mixture of blood of two individuals with different genotypes, DRB1 alleles of the minor component were detected down to 1/1,000 of the major component. This semi-nested PCR-RFLP method is useful for HLA-DRB1 typing from extremely small amounts of DNA and from mixed samples.     

Posterolateral rotatory instability of the elbow after posttraumatic cubitus varus

Patients with hypothalamic adipsic syndrome, especially in conjunction with diabetes insipidus, pose management difficulties. They are at risk of both under- and over-hydration. We present 4 patients with hypothalamic adipsic syndromes, due to different causes, illustrating the practical difficulties encountered in this condition. The principles of management, with a sliding scale of water intake related to changes in daily body weight, are discussed.     

Preparation of aldehydocelluloses from completely allylated methylcellulose,allylated ethylcellulose,and tri-O-allylcellulose by ozonization

In order to prepare aldehydocelluloses which are more stable than periodate-oxidized cellulose, completely allylated methylcellulose, allylated ethylcellulose, and tri-O-allylcellulose were subjected to ozonization followed by reduction with dimethylsulfide. The aldehydocelluloses thus prepared without any degradation showed the presence of many free aldehyde groups by IR and ¹³C-NMR spectrometries, as well as the presence of hydroxyl groups which were produced by deallylation. The degree of substitution (DS) by aldehyde group was 0.6 for the products from both completely allylated methylcellulose and tri-O-allylcellulose, and 0.02 for that from allylated ethylcellulose.     

Viscoelastic properties and coating performance of acrylic copolymers crosslinked with melamine resin

For 8 carboxy and hydroxy functional acrylic copolymers crosslinked with melamine resin, glass transition temperature (T_g), molecular weight of chain segments between crosslinked point (M_c), and polymer-solvent interaction parameters (χ_g ) were determined by dynamic mechanical measurements and swelling measurements. T_g increases and M_c decreases with the increase of hydroxyl value and the molecular weight of acrylic copolymers. T_g decreases and M_c increases with the increase of alkyl chain length of acrylate in acrylic copolymers. The film hardness, T_g and polarity of methyl methacrylate (MMA) containing acrylic-melamine-cured films are higher than those of styrene-containing acrylic-melamine-cured films, but both films are almost the same in the degree of crosslinking (maximum loss tangent, tan δ_max, and M_c). T_g increases and M_c decreases with the increase of melamine resin content for acrylic-melamine coatings. The cured film consists of the acrylic-melamine segments and the melamine-melamine segments at crosslinking points. The carboxy group enhances the crosslinking reactions at low temperatures. All films crosslinked have single glass transition temperatures and broad damping peaks, which show good compatibility. The values of χ_g of acrylic copolymer-melamine films in polar and nonpolar solvents depend on the polarity of acrylic composition and the degree of crosslinking. χ_g values of carboxy functional acrylic-melamine film in any solvents are smaller than that of carboxy and hydroxy functional acrylic-melamine film. χ_g values of MMA-containing acrylic-melamine film in polar solvents are smaller than those of styrene-containing acrylic-melamine film, but χ_g values of MMA-containing acrylic-melamine film in nonpolar solvents are larger than those of styrene-containing acrylic-melamine film. χ_g values of acrylic-melamine film in polar and nonpolar solvents increase with the increase of alkyl chain length of acrylate. The χ_g values of acrylic-melamine coatings in toluene are less than 0.3 and smaller than those of alkyd coatings.     

Synthesis of poly(N,N-dimethylaminopropylacryl amide-g-acrylic acid) and crosslinking of its trunk sequence

Summary The graft copolymers composed of weak base and weak acid sequences, i.e., poly(N,N-dimethylaminopropylacryl amide-g-acrylic acid) (poly(DAPA-AA)) including 51–87 mol% of acrylic acid (AA) were prepared by redox system using cerium(IV) ammonium sulfate as initiator. Microphase separation of two sequences was observed in basic casting solvent. The crosslinking of DAPA sequence, which had shown spheric morphology, was carried out by mean of gas-solid phase quaternization reaction with 1,4-dibromobutane. The reaction product was soluble in NaOH aq. or HCl aq. until 4.3% quaternization of DAPA unit without remarkable increase of intrinsic viscosity. And they were found to be very different in solubility from the raw graft copolymer.     

Extraction and retention of technetium-99m-ECD in human brain: dynamic SPECT and oxygen-15-water PET studies

The kinetic behavior of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in the human brain was investigated in six normal volunteers. METHODS: Dynamic SPECT and a three-compartmental model were used to estimate the rate constants of 99mTc-ECD in normal human brain. Extraction fraction (E), retention fraction (R) and permeability surface area product (PS product) of 99mTc-ECD were calculated using the rate constants. Regional cerebral blood flow (rCBF) was measured by PET with 15O-water. RESULTS: The rate constants in the cerebral cortex were estimated as 0.307 +/- 0.021 for K1 (influx constant), 0.201 +/- 0.047 for k2 (backdiffusion rate constant), 0.547 +/- 0.103 for k3 (lipophilic-to-hydrophilic conversion constant) and 0.0028 +/- 0.0012 for k5 (rate constant from lipophilic compartment to blood) at rCBF of 0.509 +/- 0.055 ml/g/min (mean +/- s.d.). The first-pass extraction, retention fraction and PS product were calculated as 0.608 +/- 0.069, 0.734 +/- 0.047 and 0.477 +/- 0.060, respectively. The first-pass extraction of 99mTc-ECD decreased significantly with increases in rCBF. The retention fraction and PS product of 99mTc-ECD did not show significant changes within the normal range of rCBF. The net extraction of 99mTc-ECD calculated from the static SPECT image obtained from 20 to 40 min was 0.358 +/- 0.039 in the cortex. CONCLUSION: Technetium-99m-ECD has a fairly high brain extraction, and its retention fraction and PS product appear to be independent of rCBF in the healthy human brain.     

Information transfer in a swarm of soldier crabs

Collective behavior is broadly observed in animal groups such as insect swarm, bird flock, and fish school. Both theoretical studies and field observations have investigated possible underlying principles based on local interaction among individuals in a group without global information via conductors or leaders. Information transferred among individuals would play a key role to understand it. In this study, to investigate how individual in a swarm uses information of its own past behavior or swarm mates’ behavior, we analyzed behavior of soldier crabs Mictyris guinotae in terms of local active information storage and local transfer entropy.     

Preparation of functional liposomes with peptide ligands and their binding to cell membranes

Two novel lipopeptides, which have the peptide ligands [α-melanocyte stimulating hormone (α-MSH)] sequence and repeated [Gly-Arg-Gly-Asp-Se (GRGDS) sequence[, are designed, synthesized by the solid-phase method, and introduced into liposome membranes by the freeze-thaw method. These liposomes bearing the peptide ligands on their surface are expected to bind to cell membranes. We have confirmed that the lipopeptides are introduced into liposome membranes almost quantitatively, while such a high degree of incorporation has not been accomplished in conventional methods. In this respect, the present method is superior to prepare surface-modified liposomes that are applicable to drug carriers and so on. We have also confirmed by using immunoelectron microscopy that the peptide ligands are actually located in an aqueous phase. It has been shown by flow cytometry that the liposome bearing α-MSH peptide ligand binds to B16 cells and the liposome bearing the repeated GRGDS sequence binds to NIH3T3 cells.