Biologic and antigenic similarity of virus-induced migration inhibition factor to conventional, lymphocyte-derived migration inhibition factor.

Macrophage migration inhibition factor (MIF) is one of a class of lymphocyte-derived mediator substances (lymphokines) which plays a role in the mechanism of cellular immunity. A variety of other soluble factors produced by non-lymphoid cells have been shown to have effects on macrophage mobility similar to that of MIF. In the present study we demonstrate that one such factor, (MIFV) derived from simian virus 40-infected kidney cells in culture, has several other properties in common with lymphocyte-derived MIF (MIFL), MIFV can be adsorbed on Sepharose bead columns conjugated with an antiserum prepared against MIFL, demonstrating at least some antigenic similarity. Moreover, MIFV can substitute for MIFL in an in vivo system involving the suppression of cutaneous manifestations of cellular immunity by intravenous injection of the lymphokine. These observations, taken in conjunction with the similarity of the in vitro effect of MIFV and MIFL, and their similar chromatographic behavior, suggest that MIFV and MIFL may be identical molecular species.     

A unique factor XIII inhibitor to a fibrin-binding site on factor XIIIA.

An 81-year-old woman, who presented with sudden episodes of spontaneous bleeding, was found to have a specific inhibitor of factor XIII. Her fibrin clots had approximately 70% gamma-gamma and no alpha polymer formation, under conditions where normal fibrin was fully cross-linked; the patient's clots were soluble in urea or monochloroacetic acid. Factor XIII activity in her plasma was 24%, measured by the dansylcadaverine incorporation assay. When mixed with normal plasma, the patient's plasma inhibited fibrin cross-linking; however, in mixtures of patient and normal plasma, there was no inhibition of factor XIII activity when assayed by the incorporation of dansylcadaverine into casein. Thus, this inhibitor was active against fibrin cross-linking but not against ligation of small molecules to casein. Consequently, gel electrophoresis of reduced, sodium dodecyl sulfate-solubilized fibrin clots was a simple, quantitative method that was used to measure inhibitor activity. This inhibitor is unique and has been designated inhibitor New Haven. It was neutralized by anti-IgG and anti-kappa. It did not inhibit the activation of factor XIII but did inhibit fibrin cross-linking. There was complex formation between the inhibitor and activated factor XIII (A', A*) but not between A2 or fibrinogen. Only A', A* and the 56-Kd fragment bound to affinity columns made with this IgG. The inhibitor significantly decreased the binding of A', A* to fibrin clots. These data indicate that the epitope for this inhibitor is in a fibrin binding site. It is hidden in the zymogen and expressed on A' and A*, indicating that the conformational change occurring with the cleavage of the activation peptide is sufficient to expose the fibrin binding site.     

Piglet pial arteries respond to N-methyl-D-aspartate in vivo but not in vitro

Controversy exists concerning whether activation of N-methyl-D-aspartate (NMDA) receptors exerts direct dilator effects on cerebral arteries. The purpose of this study was to examine the responses of isolated piglet arteries to NMDA to determine whether isolated arteries, apart from surrounding neuronal tissue, are capable of responding to NMDA. Piglet arteries (100-200 microm) were isolated from branches of the middle cerebral artery and carefully dissected free of adherent tissue. Arteries were then mounted in an arteriograph system and pressurized to either 30 mm Hg (n=8), 60 mm Hg (n=10), 80 mm Hg (n=6), or 100 mm Hg (n=5). After development of spontaneous tone, NMDA (10(-5) to 10(-3) M) was administered abluminally to the vessels, and no appreciable response was noted (for example; 10(-4) M, 30 mm Hg: 3+/-3% change in active diameter; 60 mm Hg: -4+/-3% change in active diameter). Following a thorough washout, vessels were treated with bradykinin (10(-9) to 10(-7) M), and the arteries did respond (10(-7) M, 30 mm Hg: 26+/-3% change in active diameter; 60 mm Hg: 65+/-10% change in active diameter). In contrast, 10(-5) M and 10(-4) M NMDA dilated arteries in vivo by 9+/-2% and 29+/-6% change in active diameter, respectively (n=6). These results demonstrate that isolated cerebral arteries do not respond directly to NMDA receptor activation. This work confirms our previous in vivo data and is consistent with the hypothesis that cerebral arteries respond to NMDA through a secondary interaction mediated by neuronal release of NO and not to NMDA directly.     

Pituitary microadenomas causing Cushing's disease respond to corticotropin-releasing factor

Corticotropin-releasing factor (CRF) was administered as an iv bolus to two young women with mild Cushing's disease shortly before and one week after successful transsphenoidal microadenomectomy. The dose of CRF (1 microgram/kg body weight) had previously been shown to stimulate increased plasma ACTH and cortisol in normal subjects. In the first patient, prior to surgery, there were brisk increases in ACTH and cortisol that exceeded those observed in normal subjects. ACTH rose by 2 min and reached a peak between 15-30 min. Cortisol increased by 10 min and peaked between 45-60 min. After surgery, at a time when plasma cortisol was maintained at similar levels with exogenous hydrocortisone, there was no plasma ACTH or LH, TSH and prolactin increased after administration of LRH and TRH, and GH increased in response to insulin-induced hypoglycemia. The second patient had higher basal plasma ACTH and cortisol than the first patient. CRF-induced increments in ACTH and cortisol were much less, but the time course was similar and peak levels attained were still higher than those in normal subjects. After surgery, at a time when plasma cortisol was maintained at a much lower level with exogenous hydrocortisone, there was no plasma ACTH or cortisol response. She had mild, transient diabetes insipidus. Basal levels of all other anterior pituitary hormones were normal. These results demonstrate that two microadenomas causing Cushing's disease were responsive to CRF in situ and suggest that CRF may be involved in the etiology and/or the responses to changes in plasma glucocorticoid concentrations observed in patients with Cushing's disease.     

Long-term cultured B lymphocytes and their precursors reconstitute the B-lymphocyte lineage in vivo.

Long-term in vitro cultured B lymphocytes and their precursors were tested for their ability to reconstitute a functional B-cell lineage in vivo. Continuous in vitro production of cells representing early stages of the B-lymphocyte lineage originates from a bone marrow cell type that can be distinguished from a multipotential hematopoietic stem cell. Progenitors of the long-term cultured B-lymphoid cells are recoverable in vitro after in vivo passage into lethally irradiated mice. Long-term cultured B-lymphoid cells and their progenitors reconstituted the B-lymphocyte lineage and restored normal humoral immunity in genetically defective mice. Cultured B-lymphoid cells did not cause lymphoid tumors in vivo in irradiated syngeneic mice. These findings indicate that multipotential hematopoietic stem cells are not directly required for the continued production of functionally competent B lymphocytes in vitro, and they suggest the existence of a B lymphoid progenitor cell with in vitro, and possibly in vivo, stem cell-like qualities.     

Stimulation of bone marrow-derived and peritoneal macrophages by a T lymphocyte-derived hemopoietic growth factor, persisting cell- stimulating factor

Several lines of evidence indicated that P cell-stimulating factor (PSF), a T lymphocyte-derived lymphokine known to stimulate the growth of hemopoietic stem and progenitor cells, also acted on macrophages. PSF was absorbed from medium that had been mixed for two hours at 0 degrees C with either resident or thioglycollate-elicited peritoneal cells, suggesting the presence of receptors for PSF on cells in the population. The addition of pure PSF to populations highly enriched in either resident or elicited adherent peritoneal macrophages resulted in stimulation of macrophages with morphological changes, including increases in size, spreading, vacuolation, and the number of cytoplasmic processes, together with stimulation of proliferation and the phagocytosis of opsonized yeast. PSF also stimulated the incorporation of [3H]thymidine by bone marrow-derived adherent macrophages. Addition of pure PSF to cultures that contained only a single macrophage resulted in enhanced survival and proliferation of these isolated cells, demonstrating that the effect of PSF on macrophages was direct. These results indicate that PSF can stimulate well-differentiated functional macrophages and raise the possibility that the effects of PSF on macrophages may play a regulatory role in immune responses.     

Characterization of immunologically significant unique B16 melanoma proteins produced in vivo and in vitro

Proteins unique to B16 melanoma cells grown in culture and as solid tumors have been independently described recently. As both proteins have apparent M_r of 65,000-70,000, we have more fully compared their biochemical characteristics. The M_r 65,000 protein, which is isolated from B16 cells in culture, has an aggregate molecular weight of >200,000 under nonreducing conditions. This M_r 65,000 form is shed into the culture medium exclusively and is the predominant molecular species of serum-free culture supernatants. It was found that B700, a major membrane protein of B16 cells in solid tumors, and the M_r 65,000 preparation from cultured cells were electrophoretically identical when compared under four separate sets of conditions. These two proteins also share immunologic determinants. The results suggest the identity of these two proteins isolated by completely different approaches.     

Polyadenylation of stable RNA precursors in vivo

Polyadenylation at the 3′ terminus has long been considered a specific feature of mRNA and a few other unstable RNA species. Here we show that stable RNAs in Escherichia coli can be polyadenylated as well. RNA molecules with poly(A) tails are the major products that accumulate for essentially all stable RNA precursors when RNA maturation is slowed because of the absence of processing exoribonucleases; poly(A) tails vary from one to seven residues in length. The polyadenylation process depends on the presence of poly(A) polymerase I. A stochastic competition between the exoribonucleases and poly(A) polymerase is proposed to explain the accumulation of polyadenylated RNAs. These data indicate that polyadenylation is not unique to mRNA, and its widespread occurrence suggests that it serves a more general function in RNA metabolism.     

In vitro differentiation of embryonic stem cells into lymphocyte precursors able to generate T and B lymphocytes in vivo.

Embryonic stem cells can be induced in vitro, by coculture with the stromal line RP.0.10 and a mixture of interleukins 3, 6, and 7, to differentiate into T (Joro75+) and B (B-220+) lymphocyte progenitors and other (Thy-1+, PgP-1+, c-kit+, Joro75-, B-220-, F4/80-, Mac-1-) hemopoietic precursors. The progeny of in vitro-induced embryonic stem cells can reconstitute the lymphoid compartments of T- and B-lymphocyte-deficient scid mice and generate mature T and B lymphocytes in sublethally irradiated normal mice. Exogenous cytokines can dramatically alter the developmental fate of embryonic stem cells in culture. The in vitro system described here should facilitate the study of molecular events leading to cell-lineage commitment and to the formation of hemopoietic stem cells and their immediate lymphoid progeny.     

B-cell growth factor receptor expression and B-cell growth factor response of leukemic B cell precursors and B lineage lymphoid progenitor cells

The purpose of this study was to analyze the expression of B cell growth factor (BCGF) receptors and to elucidate the biologic effects of biochemically purified natural BCGF at the B cell precursor stage of human B lineage lymphoid differentiation. The specific binding of radioiodinated high-mol-wt BCGF (125I-HMW-BCGF) and low-molecular-wt BCGF (125I-LMW-BCGF) to fresh marrow blasts from B cell precursor acute lymphoblastic leukemia (ALL) patients was initially investigated. The estimated number of radioiodinated BCGF molecules bound per blast ranged from undetectable to 24.3 X 10(3) for HMW-BCGF, and from 11.5 X 10(3) to 457.8 X 10(3) for LMW-BCGF. In 3H-TdR incorporation assays, 75% of cases showed a significant response to LMW-BCGF with a median stimulation index of 9.3. By comparison, only 33% of cases showed a significant response to HMW-BCGF with a median stimulation index of 2.4. Subsequently, B cell precursor colony assays were performed to assess and compare the biologic effects of BCGF on leukemic B lineage lymphoid progenitor cells. Among 28 cases studied, 57% responded to both HMW-BCGF and LMW-BCGF, 21% responded only to LMW-BCGF, and the remaining cases showed no proliferative response to either growth factor. The response patterns of virtually pure populations of FACS- sorted leukemic B cell precursors were essentially identical to the proliferative responses of unsorted leukemic B-cell precursors. Synergistic effects between HMW-BCGF and LMW-BCGF were observed in 80% of the cases that responded to both. The numbers of cell-bound radioiodinated BCGF molecules, the stimulation indices, as well as the number of B cell precursor colonies in BCGF-stimulated cultures showed a marked interpatient variation. Patients with structural chromosomal abnormalities (SCAs) involving 12p11-13 or patients with a Philadelphia chromosome showed a greater HMW-BCGF response at the level of leukemic progenitor cells than did other patients (P = .02). The LMW-BCGF response was significantly greater for patients with SCA than for patients without SCA (P = .04). The response of leukemic progenitor cells to HMW-BCGF or LMW-BCGF did not correlate with sex, age, disease status, FAB morphology, WBC at diagnosis, or immunophenotype. To our knowledge, this study represents the first detailed analyses of BCGF receptor expression and BCGF effects in B cell precursor ALL. The data presented provide direct evidence for the expression of functional receptors for both HMW-BCGF and LMW-BCGF in B cell precursor ALL.     

Isolation and characterization of a T lymphocyte-derived differentiation inducing factor for the myeloid leukemic cell line HL- 60

Mitogen-stimulated mononuclear blood cells produce differentiation inducing factors (DIFs) for the promyelocytic cell line HL-60. We report that DIF is produced constitutively by a malignant T lymphocyte line HUT-102. DIF was purified 7,000-fold from HUT-102 conditioned media by utilizing ion-exchange chromatography with DEAE-Sepharose, gel chromatography, Blue-Sepharose chromatography, and preparative SDS- polyacrylamide gel electrophoresis (SDS-PAGE). The final preparation is susceptible to protease treatment, has a molecular weight of 46,000, as determined by SDS-PAGE and approximately 55,000 by gel filtration, has an isoelectric point of approximately 5.2, does not adhere to lectin- Sepharose and is resistant to periodate oxidation, and is free of colony-stimulating factor. DIF induced maturation of HL-60 into phagocytizing nitro blue tetrazolium reducing cells with the morphological characteristics of myelomonocytic or monocyte-like cells. An activity, co-chromatographing with DIF, acts synergistically with retinoic acid to induce maturation not only of HL-60, but also of the monoblast-like cell line U-937 (measured as percentage of cells reducing NBT).     

乙型肝炎病毒基因分型与拉米夫定临床应用反应

目的了解常州地区乙型肝炎病毒(HBV)基因型分布特征,探讨基因型与肝功能损害、病毒复制水平及其与拉米夫定疗效关系.方法 76例慢性乙型病毒性肝炎患者每天口服拉米夫定100mg治疗,并于治疗4～6周时测定不同基因型患者的丙氨酸转氨酶(ALT)和HBV DNA,治疗48周后测定HBV DNA反跳和YMDD变异.采用巢式聚合酶链反应(nest PCR)法扩增HBV S基因区,以4色荧光标记PCR产物末端,在以毛细管高压电泳为核心技术的核酸序列分析仪上自动测序,将测序结果与基因库中登录的标准基因型序列相比较.结果 76例慢性乙型肝炎患者血清HBV DNA基因分型示B型株感染26例(34.2%),C型株感染50例(65.8%).B和C基因型患者ALT值分别为(246.3±138.8)U和(283.7±125.6)U,(t=0.335,P>0.05),HBV DNA含量分别为107.124±101.49和107.189±101.56拷贝/ml(t=0.138, P>0.05),HBeAg阳性数分别为20例和41例(χ2=0.159,P>0.05).拉米夫定治疗4～6周后,B基因型和C基因型患者ALT、HBV-DNA(阴转)、HBV DNA(拷贝/ml)均呈良好恢复状态,两组间差异无显著性.治疗48周后,HBV DNA反跳者B基因型20例,C基因型16例(χ2=13.49,P<0.001).结论常州地区HBV DNA基因型以单一B或C型为主;不同基因型患者ALT水平、病毒复制水平以及HBeAg表达水平差异均无显著性,拉米夫定对C基因型患者的疗效优于B基因型.     

In vivo recovery and half-life time of a steam-treated factor IX concentrate in hemophilia B patients

Summary Factor IX (FIX) recovery and half-life was measured in ten hemophilia B patients under standardized conditions. Each patient received a steam-treated high-purity factor IX concentrate at a dose of 19–39 U/kg body weight. FIX activity was determined using a one-stage assay, which was calibrated against the international concentrate standard (reagents from Immuno, Heidelberg). The in vivo recovery ranged from 24% to 53% (mean value 37.7%) and the half-disappearance time (HDT) from 8–30 h (mean 16.7 h). In four of the ten patients, the distribution and elimination half-lives were estimated and ranged from 0.3 h to 3.9 h (mean 1.4 h) and from 28.6 h to 39.7 h (mean 33.1 h), respectively. In six patients FIX was redetermined using a different FIX deficient plasma and a plasma standard (reagents from Merz & Dade, Munich, FRG). Recoveries and HDT based on the results obtained with this method were significantly higher (68.2% vs 39.7%; p<0.05), and longer (14.8 h vs 10.6 h; p<0.05), respectively. FIX activity was also measured by both assay systems in 100 healthy subjects (50 males, 50 females). The reagents from Immuno yielded a mean value of 0.77 U/ml, while the mean FIX activity utilizing standards and reagents from Merz & Dade was 1.11 U/ml (p<0.000001). The coefficient of correlation between the FIX activity measurements, as determined in 100 healthy subjects and 6 hemophilia B patients using the different test systems, was r=0.9 (N=159; y=0.08+1.3 * x; p<0.001). Our data suggest that recovery and HDT of factor IX concentrate strongly depend on the assay and calibration conditions and that an international FIX activity plasma standard is urgently required.     

Differential ability of B cells specific for external vs. internal influenza virus proteins to respond to help from influenza virus-specific T-cell clones in vivo.

When a helper T-cell (TH) clone specific for the hemagglutinin, neuraminidase, matrix protein, or nucleoprotein of influenza strain A/PR/8/34 is adoptively transferred to athymic mice 1 day after virus infection the anti-viral antibody response of the mouse is enhanced. This response is directed predominantly to the hemagglutinin and requires associative T-cell-B-cell interactions. Delaying transfer of the TH clone has three consequences: (i) the onset of the anti-hemagglutinin antibody response is delayed; (ii) the titer of the anti-hemagglutinin response is reduced; and (iii) the titer of the antibody in the response against the internal proteins, matrix protein and nucleoprotein, is enhanced upon transfer of matrix protein- or nucleoprotein-specific, but not hemagglutinin- or neuraminidase-specific, TH clones. Thus, there is a hierarchy of help: B cells recognizing viral surface components, hemagglutinin or neuraminidase, can receive help from TH clones specific for any of the major structural viral proteins. In contrast, B cells responding to internal viral components, matrix protein or nucleoprotein, are restricted to receiving help almost exclusively from TH clones with the same protein specificity. These observations suggest that, upon B-cell surface immunoglobulin-antigen interaction and uptake of intact virus, B cells specific for viral surface proteins process and present all major structural viral antigens, enabling the B cells to interact with TH clones specific for any virion protein. B cells recognizing internal viral components, which may be accessible to interaction with B-cell immunoglobulin receptors mainly as free proteins, would present only the protein for which they are specific and, thereby, receive help only from the TH clones of the same protein specificity.     

T-cell and mast cell lines respond to B-cell stimulatory factor 1.

The murine lymphokine B-cell stimulatory factor 1 (BSF-1) has been described previously in terms of its action on B lymphocytes. We now provide evidence that BSF-1 is also responsible for two additional biological activities. The first of these is the stimulation or maintenance of a state of activation in mouse T-cell lines. The second activity is the increase in the proliferative rate of certain mast cell lines costimulated with interleukin 3. The T-cell and mast cell activities are mediated by purified BSF-1 and copurify with BSF-1 from supernatants of certain T-cell lines. Each of these activities is inhibited by monoclonal anti-BSF-1 but not by monoclonal anti-interleukin 2 antibody. The antibody inhibition results also indicate that BSF-1 is the major or only source of these two activities in the activated T-cell supernatants that we have tested.     

Synoviocytes synthesize, bind, and respond to basic fibroblast growth factor

Rheumatoid arthritis (RA) is a systemic disease characterized by the destructive proliferation of synovial tissue. It has been suggested that this proliferative lesion resembles a malignancy. Although polypeptide growth factors have been implicated in malignant cell growth, their role in the pathogenesis of proliferative but non-neoplastic diseases such as RA has not been extensively studied. We tested the hypothesis that the synoviocyte itself may be a source of growth factor activity. We demonstrated that culture supernatants from synoviocytes obtained from patients with RA, osteoarthritis, and traumatic joint disease contain mitogenic activity. This activity has biologic properties identical to those of basic fibroblast growth factor (bFGF). Specifically, the mitogenic activity is synergistic with insulin and binds to heparin-agarose, but elutes with 2.0M NaCl. In addition, synoviocyte extracts contain a peptide with a molecular weight of approximately 16,000, which reacts with antibody specific for bFGF. Cultured synoviocytes express the bFGF gene, express receptors for bFGF, and proliferate in response to bFGF. We conclude that bFGF derived from the synoviocytes themselves may play a role in stimulating their proliferation in an autocrine manner in disease states such as RA.     

Hepatitis B in the Greater San Francisco Bay Area: an integrated programme to respond to a diverse local epidemic

Although chronic hepatitis B (CHB) affects approximately 2 million United States residents, there is no systematic screening of at-risk individuals, and most remain unaware of their hepatitis B virus (HBV) infection. Unmonitored and untreated, CHB results in a 25-30% risk of death from liver cancer and/or cirrhosis, inflicting an increasing healthcare burden in high-prevalence regions. Despite high prevalence in immigrant Asians and Pacific Islanders, among whom CHB is a leading cause of death, community and healthcare provider awareness remains low. Because safe and effective vaccines and effective antiviral treatments exist, there is an urgent need for integrated programmes that identify, follow and treat people with existing CHB, while vaccinating the susceptible. We describe an extant San Francisco programme that integrates culturally targeted, population-based, HBV screening, vaccination or reassurance, management and research. After screening over 3000 at-risk individuals, we here review our operational and practical experience and describe a simple, rationally designed model that could be successfully used to greatly improve the current approach to hepatitis B while ultimately reducing the related healthcare costs, especially in the high-risk populations, which are currently underserved.