Direct measurement of 1-mN-class thrust and 100-s-class specific impulse for a CubeSat propulsion system.

This paper presents the development of a thrust stand to enable direct measurement of thrust and specific impulse for a CubeSat propulsion system during firing. The thrust stand is an inverted pendulum and incorporates a mass balance for direct in situ mass measurement. The proposed calibration procedure allows precise performance characterization and achieves a resolution of 80 µN thrust and 0.01 g mass loss, by taking into account the drift of the thrust-stand zero caused by propellant consumption. The performance of a water micro-resistojet propulsion system for CubeSats was directly characterized as a proof of concept of the thrust stand. Continuous profiles of thrust, specific impulse, and mass consumption were acquired under various conditions in a single firing test. A thrust from 1 mN to 10 mN and a specific impulse from 45 s to 100 s with a maximum measurement uncertainty of ±15.3% were measured for the throat Reynolds number in the range 100-400.

Studies of the inheritance of human ribosomal DNA variants detected in two-dimensional separations of genomic restriction fragments.

We have investigated the variation in human ribosomal DNA repeat units as revealed in two-dimensional electrophoretic separates of genomic restriction fragments that were end-labeled at NotI cleavage sites. The transcribed portion of the ribosomal DNA results in approximately 20 labeled fragments visible on each gel as multicopy spots. We have mapped these spots to the sequences responsible for their appearance on the gels, based on their migration positions and direct sequencing of spots, and describe several previously unreported sources of variation. By studying mother/father/child families we gained information on how much of the between-repeats variation is due to differences between and within repeat arrays on homologous chromosomes. Two instances in which a child exhibited more copies of a particular fragment than were present in the parents are described and hypothesized to be due to events such as multiple unequal sister-chromatid exchanges or gene conversions.

Genetic analysis of children of atomic bomb survivors.

Studies are under way for the detection of potential genetic effects of atomic bomb radiation at the DNA level in the children of survivors. In a pilot study, we have examined six minisatellites and five microsatellites in DNA derived from 100 families including 124 children. We detected a total of 28 mutations in three minisatellite loci. The mean mutation rates per locus per gamete in the six minisatellite loci were 1.5% for 65 exposed gametes for which mean parental gonadal dose was 1.9 Sv and 2.0% for 183 unexposed gametes. We detected four mutations in two tetranucleotide repeat sequences but no mutations in three trinucleotide repeat sequences. The mean mutation rate per locus per gamete was o% for the exposed gametes and 0.5% for the unexposed gametes in the five microsatellite loci. No significant differences in the mutation rates between the exposed and the unexposed gametes were detected in these repetitive sequences. Additional loci are being analyzed to increase the power of our study to observe a significant difference in the mutation rates at the 0.05 level of significance.

[Multicenter study of the effects of sulbactam/cefoperazone on bacterial infections in the fields of internal medicine focused mainly on respiratory infections in Tochigi Prefecture].

Clinical effects of sulbactam/cefoperazone (SBT/CPZ) was studied on variety of bacterial infections in the fields of internal medicine focused mainly on respiratory infections. The total 135 infections were consisted of 103 respiratory infections, 15 urinary tract infections, 4 sepsis, 7 biliary tract infections, and 6 other infections, of which 86 patients had underlying diseases. The daily doses of SBT/CPZ were 2 to 6 g divided into 2 to 3 times i.v. or d.i.v., and the duration of administration was from 3 to 35 days. The clinical effects were judged by the attending doctors based on the changes in fever, cough, rales, chest rentogenograms, white blood cell counts, CRP values, ESR, etc. The total efficacy rate was 76.9%, and 69.0% of the isolated organism was eradicated by SBT/CPZ. The side effect was noted in 1 case, and the abnormal laboratory findings were noted in 1 case, however it was difficult to determine whether they were due to SBT/CPZ. These results suggest that the clinical usefulness of SBT/CPZ for the infections in the fields of internal medicine.

Two-dimensional gel electrophoresis of platelet polypeptides with immobilized pH gradients in capillary tubes.

Two-dimensional electrophoresis (2-DE) with immobilized pH gradient (IPG) gels in capillary tubes was used in the first-dimensional isoelectric focusing (IEF) for the separation of human platelet polypeptides. Two types of IPG tube gels, pH ranges 4-8 and 7-10, containing 8 M urea, 1% Nonidet P-40 and 0.1% pH 3.5-10 Ampholine carrier ampholytes (CA) were prepared by a simple method not requiring special equipment. The addition of CA to both gel and sample solutions was essential in the tube gel IPG system. Proteins were visualized by a modification of Wray's silver-staining technique. The degree of resolution and the number of spots observed on an IPG 2-DE gel with pH 4-8 were comparable with those obtained with O'Farrell's high-resolution 2-DE. Approximately 200 basic polypeptides, which are difficult to separate by conventional CA-based IEF 2-DE or the non-equilibrium pH gradient system, were well resolved by 2-DE with a pH 7-10 IPG tube gel in the first-dimension. The gel patterns with either pH gradient 4-8 or 7-10 were highly reproducible among gels prepared and run simultaneously. These results demonstrated the potential and usefulness of the 2-DE system with IPG gels in capillary tubes.

Characterization of three electrophoretic variants of human erythrocyte triosephosphate isomerase found in Japanese.

Three new electrophoretic variants of human erythrocyte triosephosphate isomerase (TPI) have been partially purified and compared with the normal isozyme with respect to stability, kinetics, and immunological properties. TPI 2HR1, an anodally migrating variant, was less stable than normal in guanidine denaturation and thermodenaturation tests, although it exhibited normal kinetic properties. The level of enzyme activity in erythrocytes from the proband with the phenotype TPI 1-2HR1 was about 60% of the normal mean. The variant allozyme TPI 2NG1, an anodally migrating allozyme associated with normal activity, was very thermolabile at 55 and 57 degrees C. It was also much more labile than normal in stability tests in buffers at pH 5 and pH 10, although it exhibited normal kinetic and immunological properties. TPI 4NG1, a cathodally migrating variant associated with normal activity and normal kinetic as well as immunological properties, was more stable than normal in pH 5 buffer. Family studies demonstrated that the unique characteristics of these variants are genetically transmitted. In two-dimensional electrophoresis of purified isozymes the variant subunits were separated from the normal in the pI axis. However, there is no difference between the variants and the normal in the molecular weight axis, suggesting that the variants result from single amino acid substitutions.

Origin of human triosephosphate isomerase isozymes: further evidence for the single structural locus hypothesis with Japanese variants.

Four electrophoretic variants of human erythrocyte triosephosphate isomerase (TPI) have been studied to investigate the origin of the multiple forms of human TPI, in particular the constitutive TPI-B isozyme and the cell division-associated TPI-A isozyme. The variant phenotype expressed by the constitutive TPI-B isozyme in both erythrocytes and peripheral lymphocytes was also expressed by the cell division-associated isozymes in mitogen-stimulated lymphocytes and hair root cells. These results strongly support the hypothesis of Decker and Mohrenweiser (1981) that TPI-B and TPI-A originated from the same structural gene. We also found that the isozyme e is different from TPI-A with respect to both its electrophoretic mobility and heat stability. This finding is in contrast to the recent conclusion of Yuan et al. (1981) that both the isozyme e and TPI-A are deamidation products of TPI-B.

Characterization of two new electrophoretic variants of human triosephosphate isomerase: stability, kinetic, and immunological properties.

Two new electrophoretic variants of human triosephosphate isomerase (TPI) have been partially purified and characterized. The TPI Manchester variant, a cathodally migrating electrophoretic allozyme identified in an individual with the phenotype TPI 1-Manchester, is associated with a normal level of enzyme activity in erythrocytes and normal kinetic properties. It is very thermolabile at 55 and 57 degrees C, although it is not uniquely sensitive to either guanidine-HCl or urea denaturation. The TPI Hiroshima-2 variant is an anodally migrating allozyme (the phenotype of proband is TPI 1-Hiroshima-2) with normal activity and kinetic properties and also normal stability characteristics. It is inactivated less by antisera raised against normal human TPI than either the normal or the Manchester allozyme. Dissociation-reassociation experiments utilizing these allozymes have confirmed that normal human red blood cell TPI isozymes are produced by a sequence of reactions (presumably deamidations) involving alternating subunits.

Accurate and rapid detection of heterozygous carriers of a deletion by combined polymerase chain reaction and high-performance liquid chromatography.

We have developed a technique to detect accurately heterozygous carriers of a deletion. Specific target sequences were amplified by the polymerase chain reaction (PCR), and the products subsequently were analyzed by high-performance liquid chromatography. Examples from four loci demonstrated that 24-27 cycles of amplification for a single-copy DNA, based on 50 ng of genomic DNA, results in excellent quantitation that readily permits the detection of heterozygous carriers of a deletion. We have demonstrated that triplex PCR (three targets in a single PCR) entails no loss of precision. We also have demonstrated that this method can accurately differentiate the heterozygous carriers of a deletion from normal individuals in four family studies, three for Duchenne muscular dystrophy patients and one for a hemophilia B patient.

Protection against apoptosis in chicken bursa cells by phorbol ester in vitro.

Like the thymus, the bursa of Fabricius is a site of massive lymphopoiesis accompanied by cell death in vivo. In the present study we have, therefore, examined whether chicken bursa and thymus cells exhibit apoptosis. Bursa and thymus cells from SC chickens, 4-10 weeks of age, were incubated for 8-24 hr with various reagents. Genomic DNA was isolated, electrophoresed in 3% Nusieve agarose gels, and examined for patterns of DNA fragmentation. A laddering of DNA in multiples of 200 base pairs, indicative of apoptosis, was observed particularly with bursa and, to a much smaller extent, with thymus or spleen cells. These patterns of DNA fragmentation from bursa cells could be prevented by adding phorbol myristate acetate (PMA) but not by its inactive analogue 4 alpha-PMA during culture. Ionomycin is not required for this effect and, alone, appears to be slightly toxic for bursa cells, although it does not inhibit the effect of PMA. PMA did not affect the degree of DNA fragmentation in spleen or thymus cells. The addition of the protein kinase C (PKC) inhibitor staurosporine abolished both the preventive effect of PMA on apoptosis and its protective effect on bursa cells, as assayed by [3H]thymidine incorporation 24-48 hr after the initiation of cultures. PKC inhibitors also prevented the proliferation-inducing effect of PMA + ionomycin on spleen cells. It is concluded that the activation of protein kinase C and perhaps other kinases protects against apoptosis in cultured bursa cells.

Cyclosporine A reduces T lymphocyte activity and improves airway hyperresponsiveness in corticosteroid-dependent chronic severe asthma.

BACKGROUND: Although cyclosporine A is proving effective for chronic severe asthma, its mechanism of action in this disease is unclear. OBJECTIVE: This open study was conducted to determine whether cyclosporine A therapy would reduce the degree of airway hyperresponsiveness and T lymphocyte activity. METHODS: After a 6-week run-in period, nine patients with corticosteroid-dependent chronic severe asthma were treated with cyclosporine A (initial dose 5 mg/kg per day) for 12 weeks. RESULTS: Weekly mean morning peak expiratory flow significantly increased in six subjects during the last 6 weeks of trial. Geographic mean PC20-acetylcholine (the provocative concentration of acetylcholine required to cause a 20% fall in FEV1) was 0.147 mg/mL before cyclosporine A treatment and increased to 0.216 mg/mL at 6 weeks and to 0.379 mg/mL at 12 weeks after treatment. The increase at 12 weeks was statistically significant (P < .05). The percentage of CD4-positive T lymphocytes bearing IL-2 receptor (a marker of T cell activation) in the peripheral blood decreased significantly at 6 weeks (P < .05), but returned to baseline value at 12 weeks, probably due to cyclosporine A dose reduction in seven subjects. Serum IgE levels and peripheral blood eosinophil counts, however, which are dependent on IL-4 and IL-5, respectively, were still significantly decreased at 12 weeks, suggesting lymphokine production remained suppressed even after cyclosporine A dose was reduced. CONCLUSION: Taken together, these data suggest that cyclosporine A may act in asthma, at least in part, by inhibition of T lymphocyte activation and by reducing the degree of airway hyperresponsiveness.

Malignant tumor cell lines produce interleukin-1-like factor.

Sixty-four malignant cell lines were examined for interleukin-1 (IL-1) activities in their conditioned medium using thymocyte and fibroblast proliferation assays. Sixteen cell lines showed high IL-1 activity. Comparison of these activities with human IL-1 showed similarity between some biological properties. However there was no correlation between cell origin and IL-1 activity. These results suggest the possibility that most malignant cells may produce an IL-1-like factor.

CD2 expression in murine B cell lineage.

CD2 expression in murine B cell lineage was examined by flow cytometric and immunoprecipitation studies with anti-murine CD2 mAb and by Northern blot analysis. Cell surface expression of CD2 was demonstrated on all peripheral B cells and cell lines of B lineage. The murine CD2 transcript of 1.3 kb was detected in these B cells. An identical glycoprotein of 55-67 KD was precipitated from the lysates of surface radioiodinated thymocytes, splenic T and B cells, T and B lymphomas, RL male 1 and BCL-1, with anti-murine CD2 mAb. The majority of bone marrow B cells and a half of pre-B cells were found to be positive for CD2 expression. These results indicate that murine CD2 is expressed on B cell lineage at certain differentiation stages.

Reactive arthritis after pharyngeal infection: report of two siblings.

Abstract In this report we describe the cases of two siblings with reactive arthritis (ReA) induced by pharyngeal infections. The patients were a man and his sister living with their parents. He developed arthritis in August 1997, and his younger sister developed similar symptoms in September 1998. Their disease conditions were both severe and required hospitalization. Their conditions improved with the administration of nonsteroidal anti-inflammatory drugs together with antibiotics, and both fully recovered within 1-2 weeks. Rheumatic fever was ruled out since streptococcal infections were not demonstrated with antistreptolysin O (ASO) or antistreptokinase (ASK) titers, or with pharyngeal culture. The sister suffered from a rash which was similar to erythema nodosum on her lower extremities, but neither chorea nor carditis was observed. Both human leukocyte antigen (HLA) typing analyses revealed positive results for HLA-B40 and -B39 for the brother and sister, respectively. Both HLA-B40 and -B39 are considered to be related to HLA-B27-negative ReA, most likely poststreptococcal reactive arthritis (PSRA). Therefore, the two patients were tentatively diagnosed as suffering from PSRA.

Variations among Japanese of the factor IX gene (F9) detected by PCR-denaturing gradient gel electrophoresis.

In the course of feasibility studies to examine the efficiencies and practicalities of various techniques for screening for genetic variations, the human coagulation factor IX (F9) genes of 63 Japanese families were examined by PCR-denaturing gradient gel electrophoresis (PCR-DGGE). Four target sequences with lengths of 983-2,891 bp from the F9 genes of 126 unrelated individuals from Hiroshima and their 100 children were amplified by PCR, digested with restriction enzymes to approximately 500-bp fragments, and examined by DGGE--a total of 6,724 bp being examined per individual. GC-rich sequences (GC-clamps) of 40 bp were attached to both ends of the target sequences, as far as was feasible. Eleven types of new nucleotide substitutions were detected in the population, none of which produced RFLPs or caused hemophilia B. By examining two target sequences in a single lane, approximately 8,000 bp in a diploid individual could be examined. This approach is very effective for the detection of variations in DNA and is applicable to large-scale population studies.

Chimerism in humans after intragenic recombination at the haptoglobin locus during early embryogenesis.

The human haptoglobin (HP) HP*2 allele contains a 1.7-kilobase (kb) intragenic duplication that arose after a unique nonhomologous recombination between the prototype HP*1 alleles. During a genetic screening of 13,000 children of survivors exposed to atomic-bomb radiation and 10,000 children of unexposed persons, two children suspected of carrying de novo mutations at the haptoglobin locus were identified (one in each group). DNA analyses of single-cell-derived colonies of Epstein-Barr virus-transformed B cells revealed that the two children were mosaics comprising HP*2/HP*2 and HP*2/HP*1 cells at a ratio of approximately 3:1. We infer that the latter cells are caused by reversion of one HP*2 allele to HP*1 through an intramolecular homologous recombination between the duplicated segments of the Hp*2 allele that excised one of the segments. Because the mosaicism is substantial (approximately 25%), this recombination must have occurred in early embryogenesis. The frequency of finding these children and the extent of their mosaicisms corresponds to an HP*2 to HP*1 reversion rate of 8 x 10(-6) per cell during development. This leads to the prediction that the HP*1 allele also will be represented, although usually at a very low frequency, in any HP2-2 person. We tested this prediction by using PCR for a single individual and found the HP*1 allele at frequencies of 4 x 10(-6) and 3 x 10(-6) in somatic and sperm cells. The HP*1 allele was detected by PCR in all four other HP2-2 individuals, which supports the regular but rare occurrence somatically of homologous recombination within duplicated regions in humans, in agreement with previous observations in mouse and Drosophila.

Genetic variation detected by quantitative analysis of end-labeled genomic DNA fragments.

The continuing efforts to evaluate specific human populations for altered germinal mutation rates would profit from more efficient and more specific approaches than those of the past. To this end, we have explored the potential usefulness of two-dimensional electrophoresis of DNA fragments obtained from restriction-enzyme-digested genomic DNA. This permits the analysis, on a single preparation, of approximately 2000 DNA fragments varying in size from 1.0 to 5.0 kb in the first dimension and from 0.3 to 2.0 kb in the second dimension. To enter into a genetic analysis, these fragments must exhibit positional and quantitative stability. With respect to the latter, if spots that are the product of two homologous DNA fragments are to be distinguished with the requisite accuracy from spots that are the product of only one fragment, the coefficient of variation of spot intensity should be approximately < or = 0.12. At present, 482 of the spots in our preparations meet these standards. In an examination of preparations based on three Japanese mother/father/child trios, 43 of these 482 spots were found to exhibit variation that segregated within families according to Mendelian principles. We have established the feasibility of cloning a variant fragment from such gels and establishing its nucleotide sequence. This technology should be highly efficient in monitoring for mutations resulting in loss/gain/rearrangement events in DNA fragments distributed throughout the genome.

Two-dimensional gel studies of genetic variation in the plasma proteins of Amerindians and Japanese.

Genetic variation has been studied in plasma samples from 107 Amerindian children and their parents, and 110 Japanese children and their parents by means of two-dimensional polyacrylamide gel electrophoresis. Twenty-three polypeptides were scored; the identity of nine of these is at present still unknown. Genetic variation was encountered in 11 of these polypeptides. We have previously reported that the index of heterozygosity was 6.2 +/- 0.7% for 20 "randomly selected", silver stained polypeptides scored for genetic variation in Caucasoids (Rosenblum et al. 1983b). For technical reasons only 11 of these 20 polypeptides could be routinely scored in preparations from the Amerindian samples. For these 11 polypeptides, the indices of heterozygosity in the three populations were: Amerindians, 4.5 +/- 0.6%; Japanese, 5.7 +/- 0.7%; Caucasoids, 8.0 +/- 1.1%. Even with these relatively small numbers some striking ethnic differences as regards individual polypeptides are apparent.