A novel HLA class II-independent TCR-mediated T cell activation mechanism is distinguished by the V beta specificity of the proliferating oligoclones and their capacity to generate interleukin-2

Superantigens can induce proliferative T cell responses after complex formation with major histocompatibility complex (MHC) class II antigens. In this study, highly purified variant T cells from a histocompatibility leukocyte antigen (HLA) (human major histocompatibility complex) class II-deficient patient were stimulated with toxic shock syndrome toxin 1 (TSST-1) in the presence of either HLA class II-negative or normal antigen-presenting cells (APC). The proliferative responses were similar to those of normal T cells even when HLA class II structures were absent on both responding T cells and costimulatory APC. However, the V beta specificity of responding T cells differed depending on the presence or absence of HLA class II antigens on the APC. In the presence of HLA class II-negative costimulatory APC, TSST-1 induced primarily proliferation of V beta 2-expressing T cells, whereas in the presence of normal APC virtually all responding T cells expressed V beta elements different from V beta 2. In addition, in the presence of normal APC, T cells responding to TSST-1 produced much higher amounts of interleukin-2 than T cells proliferating in the presence of HLA class II-negative APC. These findings suggest that T cells bearing selected V beta elements can directly interact with and respond to superantigen without involvement of HLA class II structures. Thus, our findings introduce a novel and distinct T cell receptor-mediated activation mechanism by which specific subpopulations of T cells respond to superantigen in the absence of HLA class II structures on APC.

[Effect of 764-3 and ligustrazine on collagen content of extrapulmonary arteries during chronic hypoxia]

OBJECTIVE

Effect of two antifibrotic Chinese drugs, 764-3 and ligustrazine, on collagen content in chronic hypoxic pulmonary hypertensive extrapulmonary arterial wall were examined.

METHODS

Since collagen contains more than 10% hydroxyproline by weight and in other proteins there are almost no hydroxyproline, collagen content was expressed as micrograms of hydroxyproline. Hydroxyproline was determined by calorimetric method after oxidized by chloramine T.

RESULTS

Both 764-3 and ligustrazine significantly inhibited the increase of pulmonary arterial pressure and elevation of hydroxyproline content in extrapulmonary arterial wall during chronic hypoxia.

CONCLUSIONS

764-3 and ligustrazine may be two hopeful therapeutic drugs for chronic hypoxic pulmonary hypertension.

Expression of members of the proteolipid protein gene family in the developing murine central nervous system

Two homologous cDNAs were previously isolated by expression cloning with a monoclonal antibody that recognized a CNS neuronal membrane protein. Both cDNAs, M6a and M6b, bore significant homology with the major myelin proteolipid protein, PLP/DM20. Our initial studies of M6 gene expression in the adult mouse brain showed that M6a was present in neurons, PLP/DM20 in oligodendrocytes, and M6b in both neurons and glia. This led to the recognition of a novel gene family that included the oligodendrocyte-specific PLP/DM20 gene and the neuronal M6 genes. These observations supported the idea that PLP/DM20 may have functions other than myelination. In this report, we describe the spatial and temporal patterns of expression of M6a, M6b, and PLP/DM20 in the developing nervous system. PLP expression was limited to the white matter. M6a appeared in post-mitotic neurons of the brain and spinal cord as early as E10, and later in the hippocampus, cerebral cortex, and the granule cells of the cerebellum. In contrast, M6b was expressed at early embryonic stages in the ventricular zone of the spinal cord, and later during development in both neurons and glia. The early appearance of M6a and M6b mRNAs in the murine CNS suggested that these molecules might play an important role in the development of a variety of neural cell types.

Age-dependent alterations of c-fos and growth regulation in human fibroblasts expressing the HPV16 E6 protein

Normal human cells in culture become senescent after a limited number of population doublings. Senescent cells display characteristic changes in gene expression, among which is a repression of the ability to induce the c-fos gene. We have proposed a two-stage model for cellular senescence in which the mortality stage 1 (M1) mechanism can be overcome by agents that bind both the product of the retinoblastoma susceptibility gene (pRB)-like pocket proteins and p53. In this study we determined whether the repression of c-fos at M1 was downstream of the p53 or pRB-like "arms" of the M1 mechanism. We examined c-fos expression during the entire lifespan of normal human fibroblasts carrying E6 (which binds p53), E7 (which binds pRB), or both E6 and E7 of human papilloma virus type 16. The results indicate a dramatic change in cellular physiology at M1. Before M1, c-fos inducibility is controlled by an E6-independent mechanism that is blocked by E7. After M1, c-fos inducibility becomes dependent on E6 whereas E7 has no effect. In addition, a novel oscillation of c-fos expression with an approximately 2-h periodicity appears in E6-expressing fibroblasts post-M1. Accompanying this shift at M1 is a dramatic change in the ability to divide in low serum. Before M1, E6-expressing fibroblasts growth arrest in 0.3% serum, although they continue dividing under those conditions post-M1. These results demonstrate the unique physiology of fibroblasts during the extended lifespan between M1 and M2 and suggest that p53 might participate in the process that represses the c-fos gene at the onset of cellular senescence.

Chromosomal mapping of the human M6 genes

M6 is a neuronal membrane glycoprotein that may have an important role in neural development. This molecule was initially defined by a monoclonal antibody that affected the survival of cultured cerebellar neurons and the outgrowth of neurites. The nature of the antigen was discovered by expression cDNA cloning using this monoclonal antibody. Two distinct murine M6 cDNAs (designated M6a and M6b) whose deduced amino acid sequences were remarkably similar to that of the myelin proteolipid protein were previously isolated. We have isolated partial human cDNA and genomic clones encoding M6a and M6b and have characterized them by restriction mapping, Southern hybridization with cDNA probes, and sequence analysis. We have localized these genes within the human genome by FISH (fluorescence in situ hybridization). The human M6a gene is located at 4q34, and the M6b gene is located at Xp22.2. A number of human neurological disorders have been mapped to the Xp22 region, including Aicardi syndrome (MIM 304050), Rett syndrome (MIM 312750), X-linked Charcot-Marie-Tooth neuropathy (MIM 302801), and X-linked mental retardation syndromes (MRX1, MIM 309530). This raises the possibility that a defect in the M6b gene is responsible for one of these neurological disorders.

In vivo protective effects of tetrapeptide AcSDKP, with or without granulocyte colony-stimulation factor, on murine progenitor cells after sublethal irradiation

Acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) demonstrated hemato-protective activity in mice after sublethal irradiation (7 GY). Bone marrow interleukin-3 (IL-3)-responsive colony-forming cells (CFC and high proliferative potential colony-forming cells (HPP-CFC) were significantly (p < 0.05) increased by day 10 after irradiation in mice receiving a continuous infusion of 1000 ng/day of AcSDKP compared to irradiated control mice. The maximum protective effect for bone marrow progenitors was achieved when AcSDKP was administered for 3 days beginning 24 hours before irradiation. Other dosages and schedules in relationship to irradiation were less active. Further, when granulocyte colony-stimulating factor (G-CSF) was administered for 10 days beginning 24 hours before irradiation. Other dosages and schedules in relationship to irradiation were less active. Further, when granulocyte colony-stimulating factor (G-CSF) was administered for 10 days after AcSDKP infusion in irradiated mice, significantly increased numbers of IL-3 responsive CSF-only control mice. In addition, platelets were significantly (p < 0.05) increased in mice receiving AcSDKP and G-CSF on days 18 and 21 after irradiation compared with mice receiving G-CSF alone. We conclude that ACSDKP has a radioprotective effect in vivo for progenitor cells, and that time of initiation and duration of AcSDKP administration relative to irradiation are crucial for these effects. Further, AcSDKP has a significant additive protective effect not only for progenitor cells but also for platelets when given in combination with G-CSF. We suggest that these in vivo observations provide a basis on which to design optimal clinical hypothesis and protocols.

[The effect of ligustrazine and 764-3 on type I and type III collagen mRNA expression in fibroblasts]

The effect of ligustrazine and 764-3 on type I and type II collagen mRNA expression in cultured fibroblasts was studied. The results showed that ligustrazine at a final concentration of 30 micrograms/ml for 24 hours could inhibit type I and type II collagen mRNA expression, 764-3 at a final concentration of 15 micrograms/ml for 24 hours could stimulate type I collagen mRNA expression, but exerted no effect on type II collagen expression. The possible mechanism of 764-3 action was discussed.

[Study on mechanism of eye-signs in blood stasis syndrome]

Through a study of 504 cases of observation group with eye-signs in blood stasis syndrome (BSS) and 112 cases of control group without eye-signs in BSS, it has been found that in the observation group, the scores of the blood concentration, viscosity, aggregability and coagulability, level of plasma thromboxane B2 (TXB2), and the ratio of TXB2/6-keto-PGF1 alpha were obviously higher than those in the control group, but level of 6-keto-PGF1 alpha was obviously lower than that in the control group; the above-mentioned parameters of blood hyperviscosity syndrome, was obviously higher than that in the control group (90.08%:2.68%); comparisons between the two groups were significantly different (P < 0.001). Certain findings of the pathological base of eye-signs in BSS were found in the investigations.

[Purification and characterization of S-layer protein from Aeromonas hydrophila]

The regular surface protein array (S-layer) present on Aeromonas hydrophila J-1 was composed of a single species of protein of apparent molecular weight 51500. This protein was extracted from whole cells by treatment with 0.2 mol/L glycine hydrocholoide (pH4.0). The protein was purified by Sephadex G-200 gel filtration chromatography and an ion exchange chromatography on DEAE-cellulose. Amino acid composition analysis showed that the protein contained 36.8% hydrophobic amino acids. But the protein did not confer hydrophobicity to the cell surface when present as an intact S-layer by salt aggregation test. ELISA and immunoblotting with two different polyclonal antisera against surface exposed-(PM) and non-surface-exposed epitopes (PR) of the protein revealed that the sensitivity of PM was higher than that of PR. Antigenic diversity of the S-layer proteins from 20 bacterial samples was analysed by ELISA with PM and PF1 (polyclonal antiserum against Aeromonas hydrophila TF7 S-layer protein). The S-layer proteins were distinguishable from the extracellular toxin of the homogeneous strains in antigenic and biochemical characterization and the S-layer proteins were one of the main protective antigens.

[Alkaloids in the flowers of Sophora viciifolia Hance]

Six alkaloids have been isolated from the flowers of Sophora viciifolia for the first time. Based on of physico-chemical methods and spectroscopic analysis, their structures have been identified as oxymatrine, oxysophocarpine, sophocarpine, matrine, sophoramine and sophoridine.

The structure of simian virus 40 refined at 3.1 A resolution

BACKGROUND

The structure of simian virus 40 (SV40), previously determined at 3.8 degree resolution, shows how its pentameric VP1 assembly units are tied together by extended C-terminal arms. In order to define more precisely the possible assembly mechanisms, we have refined the structure at 3.1 degree resolution.

RESULTS

New data from a high-intensity synchrotron source have been used for phase extension by electron-density averaging and refinement, exploiting only the strict 5-fold non-crystallographic symmetry for the real-space averaging steps. The accurate model enables us to study important structural features of the virus particle in detail. The remarkably invariant core of the VP1 pentamer bears the docking sites for the C-terminal arms from other pentamers. These contacts are the principal way in which pentameric assembly units are linked together in the capsid. Only at the interface between five-coordinated and six-coordinated pentamers do the pentamer cores appear to interact strongly. There are two cation-binding sites per VP1 monomer, seen in a soaking experiment with gadolinium nitrate. These sites are quite close to each other at the interfaces between pentamers.

CONCLUSION

We propose that the contact between five-coordinated and six-coordinated pentamers may help to generate a six-pentamer nucleus, with which further pentamers can assemble to generate the complete particle. Calcium ions probably stabilize the structure of the assembled particle, rather than direct its assembly.

Structure determination of simian virus 40 and murine polyomavirus by a combination of 30-fold and 5-fold electron-density averaging

BACKGROUND

Simian virus 40 (SV40) and murine polyomavirus (polyoma) are non-enveloped DNA tumor viruses. Their structurally similar capsids, about 500 degrees in diameter, are formed by 72 pentamers of the major coat protein VP1.

RESULTS

We describe in this paper the structure determination of SV40 and polyoma at 3.8 degree resolution, focusing particularly on methodological issues, and on a comparison of the overall molecular organization in the two related virus particles. Initial phases for SV40 were obtained by single isomorphous replacement at 6.5 degree. Phases were refined and the resolution extended to 3.8 degree by a combination of strict 5-fold and partial 30-fold electron-density averaging. The structure of polyoma was subsequently determined by systematically translating and rotating the individual VP1 pentamers, in order to find the maximum correlation between calculated and observed structure factors. The resolution was then extended to 3.8 degree, also by phase refinement through electron-density averaging.

CONCLUSION

The strategies for density averaging and for molecular replacement, used to determine the SV40 and polyoma structures, are likely to be generally useful. The individual building blocks, the VP1 pentamers, are essentially identical in both cases, as are the local details of their interactions with neighboring pentamers. Nevertheless, the arrangement of the pentamers with respect to each other is somewhat different in the two viruses. Whereas SV40 is almost spherical, with all pentamers at identical radii, the pentamers in polyoma that lie on icosahedral fivefold axes are displaced outward by about 5 degree.

Activity of acetyl-n-ser-asp-lys-pro (AcSDKP) on hematopoietic progenitor cells in short-term and long-term murine bone marrow cultures

The tetrapeptide AcSDKP is a potent inhibitor of hematopoietic stem cell proliferation. Its activity was systematically examined in murine long-term bone marrow cultures (LTBMC) and short-term liquid cultures in the presence or absence of exogenous cytokines. The effects of AcSDKP on the production of granulocyte-macrophage colony-forming cells (CFU-GM) and high proliferative potential colony-forming cells (HPP-CFC) in LTBMCs were examined. AcSDKP was added daily to LTBMCs at various concentrations (10-3--10-16M) for up to 5 weeks. AcSDKP inhibited the entry of progenitor cells into S phase as measured by 3H-thymidine suicide assay and the absolute number of progenitor cells with peak activity at 10-12 M with less activity seen at higher or lower concentrations. The number of nonadherent CFU-GM per LTBMC was unchanged from control values at 1 week of treatment with AcSDKP but was significantly depressed at weeks 3 and 5. In contrast, HPP-CFC progenitor cells were decreased throughout the treatment period, and the numbers of CFU-GM and HPP-CFC in S phase were significantly decreased throughout the treatment period. Maximum S-phase inhibitory activity was observed at 10-12 M AcSDKP. AcSDKP had no effect on the number of adherent CFU-GM or HPP-CFC, cellularity per culture or percent of adherent progenitor cells in S phase. Murine short-term bone marrow cultures were also treated with AcSDKP in the presence or absence of cytokines (interleukin-3 [LI-3], stem cell factor [SCF], or granulocyte colony-stimulating factor [G-CSF]) for various time periods. Dose-response studies showed maximum effects at 10-12 M AcSDKP when no cytokines were added and 10-14 M AcSDKP when exogenous cytokines were added. These studies indicate that the concentration of the tetrapeptide critical in obtaining an effect on hematopoietic progenitor cells, and furthermore, we report that the presence of cytokines or stromal cells also affects the response of progenitor cells to AcSDKP.

Effect of domestically-made levonorgestrel-releasing intrauterine device on the endocrine system and menstruation in monkeys

Effect of domestically-made levonorgestrel-releasing intrauterine device (LNG, release rate, 6 micrograms/day) on the endocrine system and menstruation in monkeys was investigated. The results showed that the Estradiol (E2) and progesterone (P) levels were significantly decreased 2 ovulatory cycles after insertion of the devices as compared with those before insertion in 3 monkeys (P > 0.001), suggesting an evident ovulation-suppressing effect. In 1 monkey, the E2 and P levels were the same before and after insertion, and expulsion of device was found in the monkey later. The plasma LNG concentration in 3 animals was 493.69-454.60 pg/ml and plasma LNG was not detected in 1 monkey. The hormone level returned to normal level after removal of the devices.

[Transplantation of pedicled pisiform bone to replace lunate bone with aseptic necrosis]

OBJECTIVE

To find out a new and effective method for the treatment of aseptic necrosis of lunate bone.

METHODS

Blood supply and morphology of pisiform bone were investigated in 25 upper limbs and 57 sets of carpal bone from adult cadavers on the basis of anatomical study. The lunate bone was replaced with pisiform bone of pedicled blood vessel and tendon of musculus flexor earpiulnaris in 17 patients with aseptic necrosis of lunate bone (stage III).

RESULTS

The patients were followed up for 18-46 months (average of 28 months). Complete relief of pain was obtained in all of the patients, and the range of motion of their wrists was improved. Grip strength was increased by 48.2%. Radiograph showed normal location of transferred pisiform bone without osteosclerosis and atrophy in 16 patients. Atrophy of pisiform bone was found 2 years after operation in one patient. In the 17 patients, 15 resumed their original jobs and 2 changed their jobs for other reasons.

CONCLUSION

We consider that the carpal bone chain can be completely preserved by transplantation of pedicled pisiform bone, which it is an effective method to treat aseptic necrosis stage III of lunate bone.

Cross-reactivity of Rickettsia japonica and Rickettsia typhi demonstrated by immunofluorescence and Western immunoblotting

Cross-reactivity between Rickettsia japonica and R. typhi was observed by immunofluorescence tests using sera from patients with Oriental spotted fever (OSF), from whom the causative agent was isolated and identified as R. japonica. Western immunoblotting with these sera revealed that only the 120-kilodalton surface polypeptide, i.e., rickettsial outer membrane protein (rOmp) B, has a common antigenicity with the 105-kilodalton surface polypeptide of R. typhi. In some cases, antibodies specifically reactive with R. typhi were detected in acute-phase sera followed by a significant rise in titers, possibly because of an anamnestic response to a previous infection with an R. typhi-like agent; the sera retained reactivity to R. typhi even after absorption by a homologous strain. A lipopolysaccharide (LPS)-like antigen of R. typhi was found to be reactive with some sera of OSF patients. The ladder bands on Western immunoblot of rickettsial organisms were confirmed to be polysaccharide in nature, which was demonstrated by comparing them with the pattern of silver-stained gel of proteinase K-treated rickettsial specimens after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

[Relationship between c-erbB-2 oncoprotein expression and prognosis in salivary gland malignant pleomorphic adenoma]

A monoclonal antibody AB-3 has been used immunohistochemically in a retrospective study of formalin-fixed paraffin embedded tissues of the salivary gland malignant pleomorphic adenomas (MPA). Positive staining was found in 25/60 (41.67%) of MPA. c-erbB-2 oncoprotein expression of the postoperative recurrent MPA group was higher than that of non-recurrent MPA group (P < 0.05). The postoperative 5-year survival rate of MPA with c-erbB-2 expression was considerably lower than that of without expression (P < 0.01). This observation indicates that c-erbB-2 oncoprotein expression may be an useful prognostic indicator in MPA.

[Analysis of therapeutical effectiveness in 35 cases of acute leukemia with therapy of Chinese integrated medicine]

Thirty-five cases of acute leukemia were treated with methods of Chinese integrated medicine (CIM), i.e. in the CIM group, in which the complete remission rate, partial remission rate and total remission rate were 68.5%, 20.0% and 88.5%, respectively; while those in the random control group were 42.7%,20% and 62.7%, respectively. The comparison between the two groups showed a significant difference(P < 0.05). The patients' survival period in CIM group of 1,3,5 and above 5 years was shown in 20, 12, 7 and 5 cases, but in the control group, 9,5,0 and 0 cases, respectively. The comparison between the two groups also showed an obvious difference (P < 0.01), which demonstrates that the therapeutic effect was better in the CIM group and the patients' survival period was longer in the CIM group, too.

[Quantitative determination of ursolic acid in folium Ilicis cornutae (gouguye) gathered in different and periods]

The content of ursolic acid in Folium Ilicis Cornutae (Gouguye) gathered in different periods from Yongfeng county of Jiangxi province was determined by TLCS method. The result shows that the content appears to be low in samples gathered in April, but about the same in samples of February, June, August, October and December.

Respiratory control in heart muscle during fatty acid oxidation. Energy state or substrate-level regulation by Ca2+?

Fatty acids are the main fuel for the myocardium in vivo. They increase oxygen consumption, but the regulation of their beta-oxidation is not well known. Since Ca2+ and matrix volume have been implicated in the regulation of fatty acid oxidation in liver mitochondria, we set out to investigate the effects of Ca2+ on cellular respiration and energetics in the isolated perfused rat heart when oxidizing a short-chain fatty acid. Infusion of hexanoate increased oxygen consumption, while stepwise changes in the perfusate Ca2+ concentration in the range 0.5-2.5 mM caused the mechanical work output and oxygen consumption to change in parallel. Hexanoate addition increased the cellular energy state as determined by 31P NMR and evaluated from the cytosolic [ATP]/[ADP][Pi] ratio. During fatty acid infusion the energy state decreased slightly upon Ca(2+)-induced inotropy, and after discontinuation of the hexanoate infusion the de-energization was more pronounced. The fatty acid caused an extensive partially reversible reduction of flavoproteins and NAD with a slight tendency for oxidation during Ca(2+)-induced inotropy. The data are in agreement with the notion that oxygen consumption during fatty acid oxidation is mainly determined by the energy expenditure, even in the presence of Ca(2+)-induced alterations in the inotropic state. The constancy of the redox states of mitochondrial flavins and NADH/NAD during large changes in oxygen consumption is interpreted as indicating stabilization of the mitochondrial redox states by Ca(2+)-linked regulation.

[Determination of puerarin in radix Puerariae and yufengningxin tablets by HPLC]

The contents of puerarin in Radix Puerariae and Yufengningxin Tablets were determined by HPLC. The average rates of recovery were 97.19% and 100.68% respectively, and RSD 1.05% and 1.31% respectively.

[Comparative study of diagnostic standards of eye-signs in blood stasis syndrome and of blood stasis syndrome]

By virtue of a diagnostic study of 781 cases on the basis of six standards, it was shown that for the effectiveness in diagnostic positive rate, sensitivity, specificity, false positive rate, false negative rate and comprehensive scoring, the International Diagnostic Standards for Blood Stasis Syndrome (BSS) and Chinese Diagnostic Standards for BSS were the best ones, BSS Eye-Signs and Japanese BSS Diagnostic Standards were the second, trial program of International Stasis Diagnostic Standards and Zhongshan's BSS tenderness points came the third. Each standard has its unique advantage and therefore, we should take the other's advantage to offset one's weakness. The causes of their weakness have been discussed and the rational recommendation for their application has been proposed.