Yersinia pseudotuberculosis in China

Thirty strains of Yersinia pseudotuberculosis were isolated from rabbits (17 strains), wild rats (9 strains) and house rats (4 strains) in China between 1990 and 1993. The biochemical properties of these isolates were identical with those of Y. pseudotuberculosis and no special characteristics were found in these strains. Serologically, serogroups 4b and 5b were identical to isolates found in Japan, and a new serogroup 1c and unclassified strains have also been detected. The existence of virulence-associated properties were different among strains. The pYV plasmid was detected from 6 strains of 30 isolates. This report documents the presence of Y. pseudotuberculosis in China, providing important epidemiological information.

Metabolism and actions of 2-chloro-9-(2-deoxy-2-fluoro-beta-D- arabinofuranosyl)-adenine in human lymphoblastoid cells

2-Chloro-9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)adenine (Cl-F-ara-A) is a new deoxyadenosine analogue that is resistant to phosphorolytic cleavage and deamination. Studies with a variety of cell lines demonstrated that Cl-F-ara-A is a potent cytotoxic agent; in cell-free systems, its triphosphate (Cl-F-ara-ATP) inhibited DNA polymerase alpha and ribonucleotide reductase. To further characterize its mechanism of cytotoxicity, the present study investigated the cellular metabolism of Cl-F-ara-A and the actions of its nucleotide metabolites in human T-lymphoblast leukemia CCRF-CEM cells. The mono-, di-, and triphosphates of Cl-F-ara-A accumulated in cells, with the monophosphate as its major metabolite. After washing cells into drug-free medium, the elimination of each Cl-F-ara-A nucleotide was nonlinear with a prolonged terminal phase. Incubation of CCRF-CEM cells with Cl-F-ara-A resulted in the incorporation of Cl-F-ara-AMP into DNA; a much lesser amount was associated with RNA, suggesting that Cl-F-ara-A is a more DNA-directed compound. The site of Cl-F-ara-AMP in DNA was related to the ratio of the cellular concentrations of the analogue triphosphate and the natural substrate dATP. At low Cl-F-ara-ATP:dATP values, incorporation was mainly in phosphodiester linkages at internal sites, whereas at higher Cl-F-ara-ATP:dATP values, Cl-F-ara-AMP was principally detected at terminal sites. Clonogenicity assays showed a strong inverse correlation between cell survival and Cl-F-ara-AMP incorporation into DNA. These results suggest that the incorporation of Cl-F-ara-A monophosphate into DNA is critical for the cytotoxicity of Cl-F-ara-A.

A correlation method for detecting and estimating linkage between a marker locus and a quantitative trait locus using inbred lines

The advent of molecular genetic markers has stimulated interest in detecting linkage between a marker locus and a quantitative trait locus (QTL) because the marker locus, even without direct effect on the quantitative trait, could be useful in increasing the response to selection. A correlation method for detecting and estimating linkage between a marker locus and a QTL is described using selfing and sib-mating populations. Computer simulations were performed to estimate the power of the method, the sample size (N) needed to detect linkage, and the recombination value (r). The power of this method was a function of the expected recombination value E(r), the standardized difference (d) between the QTL genotypic means, and N. The power was highest at complete linkage, decreased with an increase in E(r), and then increased at E(r)=0.5. A larger d and N led to a higher power. The sample size needed to detect linkage was dependent upon E(r) and d. The sample size had a minimum value at E(r)=0, increased with an increase in E(r) and a decrease in d. In general, the r was overestimated. With an increase in d, the r was closer to its expectation. Detection of linkage by the proposed method under incomplete linkage was more efficient than estimation of recombination values. The correlation method and the method of comparison of marker-genotype means have a similar power when there is linkage, but the former has a slightly higher power than the latter when there is no linkage.

Selective activation of VH3A10+ rheumatoid factor producing B cells by staphylococcal enterotoxin D

Staphylococcal enterotoxin D (SED) is a T cell superantigen which selectively targets alpha beta TCRs bearing particular V beta elements. A second function of SED relates to the preferential activation of a B cell subset characterized by a high frequency of rheumatoid factor (RF) producing B cells. To define the molecular basis of the SED-induced B cell repertoire shift, we have analyzed Ig heavy chain genes in B cell clones expanded after SED stimulation and compared them with B cell clones established in the presence of anti-CD3 stimulated helper cells. Gene segments of the VH3 family were most frequently utilized under both stimulation conditions (42% anti-CD3; 47% SED). Sequence analysis of VH3 gene segments demonstrated that the repertoire of VH3 elements in B cell clones from SED driven and anti-CD3 driven cultures were distinct (P = 0.01). RF activity was closely associated with the expression of selected VH3 elements. B cell clones stimulated with SED preferentially expressed VH3A10, whereas VH26 was the gene segment dominantly used in B cell clones expanded with anti-CD3 stimulated helper cells. The usage of JH and DH elements was indistinguishable in SED and anti-CD3 driven B cell clones, suggesting that SED targets VH3+ B cells through a VH-specific mechanism. Comparison of the closely related sequences of the SED responsive VH3A10 and the SED non-responsive VH26 element suggested a role of a sequence polymorphism in the CDR2 reminiscent of B cell reactivity to conventional antigens. In contrast to conventional antigens, SED can induce differentiation of a high frequency of naive B cells. Thus, this staphylococcal enterotoxin combines selective activation of T cells with selective activation of B cells and might be able to direct T cell help to RF producing B cells.

[Determination of loganin in Cornus officinalis Sieb. et Zucc. by TLC scanner]

The content of loganin extracted from Cornus of ficinalis was determined directly on a CS-930 TLC scanner. The method is simple and sensitive, and can serve as an index for checking the quality of C. of ficinalis.

Cloning and characterization of the cDNA encoding a novel human pre-B-cell colony-enhancing factor

A novel gene coding for the pre-B-cell colony-enhancing factor (PBEF) has been isolated from a human peripheral blood lymphocyte cDNA library. The expression of this gene is induced by pokeweed mitogen and superinduced by cycloheximide. It is also induced in the T-lymphoblastoid cell line HUT 78 after phorbol ester (phorbol myristate acetate) treatment. The predominant mRNA for PBEF is approximately 2.4 kb long and codes for a 52-kDa secreted protein. The 3' untranslated region of the mRNA has multiple TATT motifs, usually found in cytokine and oncogene messages. The PBEF gene is mainly transcribed in human bone marrow, liver tissue, and muscle. We have expressed PBEF in COS 7 and PA317 cells and have tested the biological activities of the conditioned medium as well as the antibody-purified protein in different in vitro assays. PBEF itself had no activity but synergized the pre-B-cell colony formation activity of stem cell factor and interleukin 7. In the presence of PBEF, the number of pre-B-cell colonies was increased by at least 70% above the amount stimulated by stem cell factor plus interleukin 7. No effect of PBEF was found with cells of myeloid or erythroid lineages. These data define PBEF as a novel cytokine which acts on early B-lineage precursor cells.

[A model of orthotopic transplantation of human hepatoma established in nude mice tumor inhibition studies]

We established a model of orthotopic transplantation of human hepato-carcinoma. The tissues from human hepatoma LTNM4 were surgically implanted into the livers of 32 BALB/c nu/nu nude mice. These led to the development of tum or masses in the livers of 31 nude mice; the rate of success was about 96.8% (31/32). Furthermore, this model was applied to the studies on the tumor inhibitory action of DHAQ-PBCA-NS, a hepatic targeting preparation for anticarcinoma. Satisfactory effect was attained. The result has proved the applicability of this animal model to researches on hepatic targeting preparations against carcinoma.

[Amino acid analysis of retinal S-antigen and interphotoreceptor retinoid-binding protein]

Retinal S-antigen and interphotoreceptor retinoid-binding protein (IRBP) were purified by DEAE-Sephacel ionexchange chromatography and Con A Sepharose affinity chromatography. Amino acid analysis of the S-antigen and IRBP was carried out and compared with that presented by others. The possible reason for difference with regard to some amino acids and related problems were analyzed and discussed.

Restrictions in the repertoire of allospecific T cells. Contribution of the alpha-helical sequence polymorphism of HLA-DR molecules

We have studied the molecular diversity of the allogeneic TCR repertoire specific for the HLA-DR4 variant, DRB1*0404, by analyzing the V beta gene segment usage of CD4+ T cell clones from nine different donors and comparing the V beta repertoire in allospecific and unselected T cell populations. To investigate the forces shaping the repertoire of the alloreactive T cell response we compared the diversity of TCR specificities utilized in very similar and in disparate responder/stimulator combinations. Six of the responders shared the HLA-DRB1*0401 allele, which differs from the HLA-DRB1*0404 allele by only two amino acid substitutions at positions 71 and 86 of the HLA-DR beta 1 chain; three responders expressed HLA-DRB1 alleles with extensive polymorphisms compared with the stimulator HLA-DRB1 allele. In all nine responders, TCR specificities recruited to recognize HLA-DRB1*0404 were strongly biased toward the dominant usage of one to three V beta elements. Despite some degree of heterogeneity between different responders, the overall pattern was very similar with a hierarchy of TCR V beta elements expressed by HLA-DRB1*0404 specific T cells. A core group of V beta elements (V beta 6, 5, 2, 13.2, 18, and 7) was preferentially used, whereas other V beta elements including V beta 3, 4, and 8 were infrequently used or not used at all. Sequencing of the VDJ beta region from selected T cell clones showed no junctional bias associated with the preferential V beta gene segment usage. Surprisingly, the T cell diversity in focused and in complex alloreactive responses were equally biased. The finding that HLA-DR4+ and DR4- donors exhibited a similar bias supports the interpretation that the alpha-helical HLA-DR structure of the stimulator cell has a dominant contribution in shaping the alloreactive repertoire.

Restrictions in the repertoire of allospecific T cells. Contribution of the alpha-helical sequence polymorphism of HLA-DR molecules

We have studied the molecular diversity of the allogeneic TCR repertoire specific for the HLA-DR4 variant, DRB1*0404, by analyzing the V beta gene segment usage of CD4+ T cell clones from nine different donors and comparing the V beta repertoire in allospecific and unselected T cell populations. To investigate the forces shaping the repertoire of the alloreactive T cell response we compared the diversity of TCR specificities utilized in very similar and in disparate responder/stimulator combinations. Six of the responders shared the HLA-DRB1*0401 allele, which differs from the HLA-DRB1*0404 allele by only two amino acid substitutions at positions 71 and 86 of the HLA-DR beta 1 chain; three responders expressed HLA-DRB1 alleles with extensive polymorphisms compared with the stimulator HLA-DRB1 allele. In all nine responders, TCR specificities recruited to recognize HLA-DRB1*0404 were strongly biased toward the dominant usage of one to three V beta elements. Despite some degree of heterogeneity between different responders, the overall pattern was very similar with a hierarchy of TCR V beta elements expressed by HLA-DRB1*0404 specific T cells. A core group of V beta elements (V beta 6, 5, 2, 13.2, 18, and 7) was preferentially used, whereas other V beta elements including V beta 3, 4, and 8 were infrequently used or not used at all. Sequencing of the VDJ beta region from selected T cell clones showed no junctional bias associated with the preferential V beta gene segment usage. Surprisingly, the T cell diversity in focused and in complex alloreactive responses were equally biased. The finding that HLA-DR4+ and DR4- donors exhibited a similar bias supports the interpretation that the alpha-helical HLA-DR structure of the stimulator cell has a dominant contribution in shaping the alloreactive repertoire.

[Effect of superoxide dismutase on experimental allergic uveitis]

In this study, experimental allergic uveitis (EAU) in guinea pigs was induced by an injection of bovine serum albumin (BSA) into the vitreous after having pre-immunized them intradermally with BSA plus incomplete Freund adjuvant, and the effect of superoxide dismutase (SOD) on EAU was observed. The result showed that, histopathologically, the phlogistic cell infiltration and exudation within the anterior ocular part of the SOD- treated animals reduced notably. It is suggested that SOD which can scavenge the free radical superoxide anion may alleviate the cellular reaction in the pathological process of uveitis.

Beam profile flattener for Gaussian beams

We describe a novel technique to make a Gaussian laser beam profile spatially flat. We exploit the angular dependence of the transmission of an étalon to tailor the spatial profile to the desired form. A simple analysis shows why our method works so well and how an étalon could be tuned to give the optimum results at all wavelengths. This technique has enormous advantages over other methods.

Clinical value of lung scintigraphy with Tc-99m gluconate in distinguishing benign from malignant lung diseases

One hundred patients were studied with three-phase lung scintigraphy with Tc-99m gluconate. The results showed that there were statistically significant differences between benign and malignant lung lesions in the intensity of accumulation, the blood supply index ratio, and the radioactive uptake ratio. However, no difference was observed between the benign lung lesions and the healthy lungs. Analysis of false negatives and false positives revealed that false negatives had something to do with the cell types of the malignancies, in addition to the relatively small size of the lesions; the false positives were mostly caused by acute inflammation, for which obstructive pneumonitis might be responsible in part. It is concluded that Tc-99m gluconate is tumor-avid and can be used as an agent for positive imaging of lung cancer, because quantitative parameters, blood supply index ratio, and radioactive uptake ratio are more objective in distinguishing malignant lung lesions from benign ones, and are of relatively higher sensitivity and specificity. Thus, lung scintigraphy with Tc-99m gluconate provides an efficient supplementary measure for differentiating between malignant and benign lung lesions.

Homozygosity for the HLA-DRB1 allele selects for extraarticular manifestations in rheumatoid arthritis

Seropositive rheumatoid arthritis is genetically linked to a group of HLA-DRB1 alleles sharing a sequence motif within the third hypervariable region. Controversy exists over the role of the distinct allelic variants in affecting not only the risk to develop disease, but also in modifying the expression of the disease. We have stratified 81 patients according to their patterns of disease manifestations and identified the HLA-DRB1 alleles by polymerase chain reaction amplification and subsequent oligonucleotide hybridization. To identify precisely the allelic combinations at the HLA-DRB1 locus, homozygosity was confirmed by locus-specific cDNA amplification and subsequent sequencing. Our study demonstrated a high correlation of allelic combinations of disease-associated HLA-DRB1 alleles with the clinical manifestations. Characteristic genotypes were identified for patients who had progressed toward nodular disease and patients who had developed major organ involvement. Rheumatoid nodules were highly associated with a heterozygosity for two disease associated HLA-DRB1 alleles. Homozygosity for the HLA-DRB1*0401 allele was a characteristic finding for RA patients with major organ involvement. Our data suggest a role of the disease-associated sequence motif in determining severity of the disease. The finding of a codominant function of HLA-DRB1 alleles suggests that the biological function of HLA-DR molecules in thymic selection might be important in the pathogenesis of RA.

Purification of bovine interphotoreceptor retinoid-binding protein and its uveitogenicity in Lewis rats

Interphotoreceptor retinoid-binding protein, IRBP, not only functioning as a shuttle to carry the retinoid between photoreceptor cells and pigment epithelium, but also inducing experimental autoimmune uveoretinitis (EAU), was purified by ConA Sepharose affinity chromatography from the fractions containing IRBP obtained in the course of ion-exchange chromatography by which the bovine retinal S-antigen was purified. This much simplified method allows more rapid purification of the two kinds of protein. EAU was successfully induced with injecting 50 micrograms of IRBP emulsified with Freund's complete adjuvant into the right hind footpads of Lewis rats. It was characterized by panophthalmia or endophthalmia with the severest damage in the posterior retina. Lymphocytes, mononuclear and polymorphonuclear cells were found to be the inflammatory cells of infiltration, with lymphocytes being predominant.

[Pharmacological studies on the Chinese drug radix Angelicae dahuricae]

Several species of the Chinese drug Angelica dahurica from different habitats have been studied in terms of anti-inflammatory, analgesic and antipyretic actions and acute toxicity. The medical value of these species is reported in this paper as a guideline for their clinic application.

[Longitudinal changes of serum specific antibodies in Lewis rats immunized with IRBP]

The serum antibodies specific to either interphotoreceptor retinoid-binding protein (IRBP) or retinal S-antigen were longitudinally determined in Lewis rats immunized with 50 x 10(-6)g of IRBP emulsified with complete Freund's adjuvant. To our knowledge, it is the first time to purify IRBP and to address the experiment with IRBP in China. It was shown that the antibody specific to IRBP appeared on the 7th day, followed by a gradual increase, and reached its peak on the 26th day after immunization. No antibody specific to S-antigen was found. The relation between anti-IRBP antibody and experimental autoimmune uveoretinitis (EAU) which occurred in the increasing phase of the antibody suggests that the humoral immunity may be implicated in the pathogenesis of EAU.

HLA antigens and Vogt-Koyanagi-Harada's disease

Thirty patients with Vogt-Koyanagi-Harada's disease were typed for HLA-A and HLA-B antigenic determinants by a microlymphocytotoxicity technique. HLA-B22 antigen showed an increased frequency of 43.3% in the patient group (relative risk = 8.69; exact P < 0.0001; corrected P < 0.0025) compared with normal control group (frequency = 7.69%). This association suggests that immunogenetic factor may play an important role in the pathogenesis of Vogt-Koyanagi-Harada's disease.

[Determination of coumarins in radix Angelicae Dahuricae before and after processing]

This paper reports the contents of coumarins in Radix Angelicae Dahuricae before and after processing. By CS-930 TLC scanner, the total contents have been determined to be 0.190%, 0.571%, 0.178% and 0.421% respectively.

[Serum antibodies to bovine retinal S antigen in the patients with uveitis and healthy subjects]

The antibodies to bovine S-Ag in sera were determined by ELISA in 43 patients with acute or chronic, anterior or panuveitis and in 32 healthy persons as controls. The results showed that the antibodies titers to bovine S-Ag in the patients with panuveitis were not different from those in the controls (P greater than 0.05). However the antibody titers to bovine S-Ag in the patients with anterior uveitis were significantly lower than those in the controls (0.01 less than P less than 0.05). It is suggested that there are naturally occurring antibodies to S-Ag in health persons. The relationship between antibodies to S-Ag and uveitis is discussed. It is indicated that natural antibodies to S-Ag may play a protective role in the healthy subjects.

[Effects of danggui shaoyao powder on blood rheological indexes and prostaglandin F2 alpha in dysmenorrhea patients]

The results showed that several blood rheological indexes of dysmenorrhea patients were abnormal, the contents of plasma prostaglandin F2 alpha (PGF2 alpha) and menstrual blood PGF2 alpha of the patients were significantly higher than those of the normal women. The abnormal indexes were recovered to normal range after the patients had been treated with Danggui Shaoyao Powder for 3 months. Danggui Shaoyao Powder had better actions of improving the abnormal indexes than Tianqi Dysmenorrhea Capsule did.

[plants of Coptis from Tibet and Yunnan]

In this paper the relationship of Tibetan Huanglian and Yunnan Huanglian with Coptis teeta has been studied. The distribution and taxonomic features of Tibetan Huanglian are just the same as Coptis teeta, but quite different from Yunnan Huanglian. The results reveal that Tibetan Huanglian and Yunnan Huanglian are different in botanical origin.

Frequency stabilization of an AlGaAs laser diode by a Fabry-Perot interferometer locked to a laser beam frequency-locked to the D(2) line of a Cs atomic beam

An AlGaAs laser diode (slave laser) has been frequency-locked to a Fabry-Perot interferometer which is locked to a diode laser (master laser) beam frequency-locked to the D(2) line of a Cs atomic beam. Frequency-locking of the Fabry-Perot interferometer to the master laser beam frequency-locked to a resonance line of an atomic beam greatly improves its long-term frequency stability. Therefore, it substantially improves the slave laser diode frequency stability frequency-locked to it. The measured frequency stabilities show that the very high frequency stability of the D(2) line of a Cs atomic beam has been transferred to the slave laser by this frequency-locking system within 1.6 x 10(-11)(10s). This system can be used for building a network of diode lasers with high frequency stability.