Relationship between Phenotypic Changes of Dendritic Cell Subsets and the Onset of Plateau Phase during Intermittent Interferon Therapy in Patients with CHB

Objective

This study aimed to evaluate whether the onset of the plateau phase of slow hepatitis B surface antigen decline in patients with chronic hepatitis B treated with intermittent interferon therapy is related to the frequency of dendritic cell subsets and expression of the costimulatory molecules CD40, CD80, CD83, and CD86.

Method

This was a cross-sectional study in which patients were divided into a natural history group (namely NH group), a long-term oral nucleoside analogs treatment group (namely NA group), and a plateau-arriving group (namely P group). The percentage of plasmacytoid dendritic cell and myeloid dendritic cell subsets in peripheral blood lymphocytes and monocytes and the mean fluorescence intensity of their surface costimulatory molecules were detected using a flow cytometer.

Results

In total, 143 patients were enrolled (NH group, n = 49; NA group, n = 47; P group, n = 47). The results demonstrated that CD141/CD1c double negative myeloid dendritic cell (DNmDC)/lymphocytes and monocytes (%) in P group (0.041 [0.024, 0.069]) was significantly lower than that in NH group (0.270 [0.135, 0.407]) and NA group (0.273 [0.150, 0.443]), and CD86 mean fluorescence intensity of DNmDCs in P group (1832.0 [1484.0, 2793.0]) was significantly lower than that in NH group (4316.0 [2958.0, 5169.0]) and NA group (3299.0 [2534.0, 4371.0]), Adjusted P all < 0.001.

Conclusion

Reduced DNmDCs and impaired maturation may be associated with the onset of the plateau phase during intermittent interferon therapy in patients with chronic hepatitis B.

[A real-world study on the features of postpartum hepatitis flares in pregnant women with chronic HBV infection]

Objective: To analyze the clinical features of postpartum hepatitis flares in pregnant women with hepatitis B virus (HBV) infection. Methods: A retrospective study was conducted. Patients who met the enrollment criteria were included. Liver function and HBV virology tests were collected from pregnant women with chronic HBV infection at delivery, 6, 24, 36, and 48 weeks after delivery through the hospital information and test system. Additionally, antiviral therapy types and drug withdrawal times were collected. Statistical analysis was performed on all the resulting data. Results: A total of 533 pregnant women who met the inclusion criteria were included, with all patients aged (29.5±3.7) years old. A total of 408 cases received antiviral drugs during pregnancy to interrupt mother-to-child transmission. There was no significant difference in the levels of alanine aminotransferase (ALT, z = -1.981, P = 0.048), aspartate aminotransferase (AST, z = -3.956, P < 0.001), HBV load (z = -15.292, P < 0.001), and HBeAg (z = -4.77, P < 0.001) at delivery in patients who received medication and those who did not. All patients ALT, AST, total bilirubin, direct bilirubin, and albumin showed an upward trend within six weeks after delivery. A total of 231 cases developed hepatitis within 48 weeks after delivery. Among them, 173 cases first showed ALT abnormalities within six weeks postpartum. Conclusion: Hepatitis flare incidence peaked six weeks after delivery or six weeks after drug withdrawal in pregnant women with chronic HBV infection.

[Research progress of pyruvate kinase type M2 in hepatocellular carcinoma]

Primary hepatocellular carcinoma is one of the most common high-grade malignant tumors in the world. Its incidence ranks fifth among malignant tumors in China, and various therapeutic measures have poor curative effect. Pyruvate kinase type M2 is a key enzyme in the glycolytic pathway, and its abnormal expression in liver cancer is closely related to the proliferation, metastasis, diagnosis, treatment, prognosis, as well as drug and radiation resistance. Therefore, multi-pathway targeted regulation of pyruvate kinase type M2 use is expected to become a new direction for the treatment of primary liver cancer.

Mobilising Expertise and Resources to Close the Radiotherapy Gap in Cancer Care

Closing the gap in cancer care within low- and middle-income countries and in indigenous and geographically isolated populations in high-income countries requires investment and innovation. This is particularly true for radiotherapy, for which the global disparity is one of the largest in healthcare today. New models and paradigms and non-traditional collaborations have been proposed to improve global equity in cancer control. We describe recent initiatives from within the radiation oncology community to increase access to treatment, build the low- and middle-income countries' radiation oncology workforce, mobilise more professionals from within high-income countries and raise awareness of the global need for equitable cancer care.

Proteomic analysis reveals the mechanisms of Mycena dendrobii promoting transplantation survival and growth of tissue culture seedlings of Dendrobium officinale

AIMS

Dendrobium officinale is an important traditional Chinese medicinal herb. Its seedlings generally show low survival and growth when transferred from in vitro tissue culture to a greenhouse or field environment. In this study, the effect of Mycena dendrobii on the survival and growth of D. officinale tissue culture seedlings and the mechanisms involved was explored.

METHODS AND RESULTS

Mycena dendrobii were applied underneath the roots of D. officinale tissue culture seedlings. The seedling survival and growth were analysed. The root proteins induced by M. dendrobii were identified using two-dimensional (2-D) electrophoresis and matrix-assisted laser desorption/ionization time-of-flight MS (MALDI-TOF-MS). Mycena dendrobii treatment significantly enhanced survival and growth of D. officinale seedlings. Forty-one proteins induced by M. dendrobii were identified. Among them, 10 were involved in defence and stress response, two were involved in the formation of root or mycorrhizae, and three were related to the biosynthesis of bioactive constituents.

CONCLUSIONS

These results suggest that enhancing stress tolerance and promoting new root formation induced by M. dendrobii may improve the survival and growth of D. officinale tissue culture seedlings.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides a foundation for future use of M. dendrobii in the large-scale cultivation of Dendrobiums.

Roles of p38 MAPK in the regulation of the inflammatory response to swine influenza virus-induced acute lung injury in mice

Swine influenza virus (SIV), one of the most important zoonotic agents, is associated with major public health concerns. The current study was conducted to investigate the role of p38 mitogen-activated protein kinase (p38 MAPK) in the regulation of the inflammatory response to acute lung injury (ALI) induced by SIV of H9N2 subtype (H9N2-SIV) in mice. For this purpose, BALB/c mice were intranasally infected with 20 LD(50) of H9N2-SIV (infected group), while non-infected mice served as control (control group). To assess the effect of p38 MAPK, its specific inhibitor SB203580 was employed followed by SIV infection (SB group). At various times after infection, mouse lungs were subjected to pathological and histological observations and detection of inflammatory cytokines tumor necrosis factor α (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 and phosphorylated p38 MAPK. The obtained results showed obvious inflammatory responses, injury and raised levels of inflammatory cytokines and phosphorylated p38 MAPK in the lungs of virus-infected mice. In the mice inoculated with the virus alone, the level of phosphorylated p38 MAPK increased from day 2 and peaked at day 6 post infection (p.i.). However, SB203580 caused lower increases in inflammatory cytokines and phosphorylated p38 MAPK and a milder lung injury. These findings indicate that the activation of p38 MAPK upregulated the inflammatory responses to H9N2-SIV-induced ALI, increased its severity and promoted the production of inflammatory cytokines.

Chlamydia psittaci exposure in pet birds

Chlamydia psittaci is a zoonotic pathogen with a wide range of avian hosts and may be transmitted to humans and cause severe disease. To assess the risk of psittacosis posed by pet birds, the seroprevalence of Chlamydia psittaci antibodies in 360 Eurasian siskins (Carduelis spinus), 289 oriental skylarks (Alauda arvensis) and 36 black-tailed grosbeaks (Coccothraustes migratorius) in Gansu province, north-western China was detected by an indirect haemagglutination assay. Twenty-seven out of 289 (9.34 %) Alauda arvensis, 45 out of 360 (12.50 %) Carduelis spinus and 2 out of 36 (5.56 %) Coccothraustes migratorius were positive for Chlamydia psittaci infection at a cut-off dilution of 1 : 16. The prevalence of Chlamydia psittaci was higher in Carduelis spinus (12.5 %) than in Alauda arvensis (9.34 %) and Coccothraustes migratorius (5.56 %); however, the differences were not statistically significant (P>0.05). Statistical analysis indicated that Chlamydia psittaci seroprevalence in adult pet birds (12.4 %, 67/540) was significantly higher than that in juvenile pet birds (4.83 %, 7/145) (P<0.01). There was no statistical difference in Chlamydia psittaci seroprevalence between male (12.4 %) and female (8.27 %) birds. To our knowledge, this is the first report indicating the seroprevalence of Chlamydia psittaci exposure in pet birds in China. Our results indicate that close contact with pet birds poses the risk of zoonotic transmission of Chlamydia psittaci.

MH II-DAB gene expression in grass carp Ctenopharyngodon idella (Valenciennes) after infection with the ciliate parasite, Ichthyophthirius multifiliis

The grass carp, Ctenopharyngodon idella (Valenciennes), is one of the most extensively aquacultured freshwater fish in China. However, because of the lack of effective control measures and the high-density culture environment, considerable economic losses are caused by infection of C. idella with the parasitic ciliate, Ichthyophthirius multifiliis. The major histocompatibility (MH) DAB gene belongs to antigen-presented genes in the class II genomic region, which is associated with parasite resistance. To understand the relationship of the DAB gene with I. multifiliis infection in grass carp, the expression profiles of MH II-DAB were studied in tissues using real-time quantitative polymerase chain reaction. The results showed that expression of the MH II-DAB gene was up-regulated in head kidney after I. multifiliis infection, and the expression peak appeared earlier in the study (case) group than in the control group. The obvious up-regulation peak of MH II-DAB gene was found at days 2 and 4 in skin; at 12 h to day 4 in spleen; at 12 h and days 1 and 6 in gill; and at day 10 in blood, whereas the MH II-DAB gene was down-regulated in liver and intestines after I. multifiliis infection. These results have implications for better understanding C. idella resistance to I. multifiliis infection.

Seroprevalence of Chlamydia psittaci infection in market-sold adult chickens, ducks and pigeons in north-western China

Chlamydia psittaci, the agent of psittacosis in humans, infects a wide range of avian species. To assess the risk of psittacosis posed by domestic birds in the urban environment, the prevalence of C. psittaci antibodies in 413 chickens (Gallus domesticus; 305 caged and 108 free-range), 334 ducks (Anas spp.; 111 caged and 223 free-range) and 312 pigeons (Columba livia) in Lanzhou, north-western China, was detected using the indirect haemagglutination assay. The specific antibodies were found in sera of 55 (13.32 %) chickens, 130 (38.92 %) ducks and 97 (31.09 %) pigeons. Statistical analysis showed that the seroprevalence of C. psittaci infection in chickens was significantly lower than that in ducks and pigeons (P<0.05). The C. psittaci seroprevalence in caged and free-range chickens was 7.54 % and 29.63 %, respectively, and the difference was statistically significant (P<0.05). The C. psittaci seroprevalence in caged and free-range ducks was 26.13 % and 45.29 %, respectively (P<0.05). To our knowledge, this is the first study indicating the presence of C. psittaci infection in market-sold chickens, ducks and pigeons in north-western China. Close contact with these birds is associated with a risk of zoonotic transmission of C. psittaci. Public education should be implemented to reduce the risk of avian to human transmission of such a pathogenic agent.

Modulation of mouse macrophage proteome induced by Toxoplasma gondii tachyzoites in vivo

Toxoplasma gondii is an obligate intracellular protozoan parasite, which can invade and multiply within the macrophages of humans and most warm-blooded animals. Macrophages are important effector cells for the control and killing of intracellular T. gondii, and they may also serve as long-term host cells for the replication and survival of the parasite. In the present study, we explored the proteomic profile of macrophages of the specific pathogen-free Kunming mice at 24 h after infection with tachyzoites of the virulent T. gondii RH strain using two-dimensional gel electrophoresis combined with matrix-assisted laser desorption ionization time-of-flight (TOF)/TOF tandem mass spectrometry. Totally, 60 differentially expressed protein spots were identified. Among them, 52 spots corresponded to 38 proteins matching to proteins of the mouse, including actin, enolase, calumenin, vimentin, plastin 2, annexin A1, cathepsin S, arginase-1, arachidonate 12-lipoxygenase, and aminoacylase-1. Functional prediction using Gene Ontology database showed that these proteins were mainly involved in metabolism, structure, protein fate, and immune responses. The findings provided an insight into the interactive relationship between T. gondii and the host macrophages, and will shed new lights on the understanding of molecular mechanisms of T. gondii pathogenesis.

Sensitive and rapid detection of Paragonimus westermani infection in humans and animals by loop-mediated isothermal amplification (LAMP)

In the present study, a loop-mediated isothermal amplification (LAMP) assay was developed and validated for the detection of Paragonimus westermani adults, metacercariae, and eggs in human and animal samples. The LAMP amplification can be finished in 45 min under isothermal condition at 60°C by employing a set of four species-specific primer mixtures and the results can be checked by naked-eye visualization. No amplification products were detected with deoxyribunucleic acid (DNA) of related trematode species including Fasciola hepatica, Fasciola gigantica, Clonorchis sinensis, Opisthorchis viverrini, Schistosoma mansoni, and Schistosoma japonicum. The method was further validated by examining P. westermani DNA in intermediate hosts including freshwater crabs and crayfish, as well as in sputum and pleural fluid samples from patients of paragonimiasis. These results indicated that the LAMP assay was highly specific, sensitive, and rapid, and it was approximately 100 times more sensitive than conventional specific PCR. The LAMP assay established in this study provides a rapid and sensitive tool for the detection of P. westermani DNA in freshwater crabs, crayfish, sputum, and pleural fluid samples, which has important implications for effective control of human paragonimiasis.

Sensitive and rapid detection of Clonorchis sinensis infection in fish by loop-mediated isothermal amplification (LAMP)

The fish-borne clonorchiasis caused by the oriental liver fluke Clonorchis sinensis is endemic in a number of countries with over 35 million people being infected globally. Rapid and accurate detection of C. sinensis in its intermediate host fish is important for the control and prevention of clonorchiasis in areas where the disease is endemic. In the present study, we established a loop-mediated isothermal amplification (LAMP) approach for the sensitive and rapid detection of C. sinensis metacercariae in fish. The specificity and sensitivity of primers designed from the C. sinensis cathepsins B3 gene were evaluated, and specific amplification products were obtained with C. sinensis, while no amplification products were detected with DNA of related trematodes, demonstrating the specificity of the assay. The LAMP assay was proved to be 100 times more sensitive than a conventional polymerase chain reaction for detection of C. sinensis. The established LAMP assay provides a useful tool for the rapid and sensitive detection of C. sinensis in fish, which has important implications for the effective control of human clonorchiasis.

The influence of caecectomy on amino acid availability of three feedstuffs for ganders

1. Experiments were conducted to assess the influence of caecectomy on amino acid availability (AAA) of three feedstuffs for goose. 2. Nine caecectomised and 9 intact Yangzhou ganders, 24 weeks old, were used in these experiments. Fish meal, soybean meal and cottonseed meal were used as the sole source of protein. The endogenous amino acid (AA) losses were evaluated by a nitrogen (N)-free diet method. The influence of caecectomy on apparent amino acid availability (AAAA) in fish meal, soybean meal and cottonseed meal was assessed in experiment 1 and true amino acid availability (TAAA) of three protein diets was determined in experiment 2. 3. Results showed that, in the soybean meal and cottonseed meal, the AAAA and TAAA of most AA determined by the intact ganders were higher than in the caecectomised ganders; in the fish meal, the AAAA and TAAA of most AA determined by the intact ganders were lower than in the caecectomised ganders. 4. Results of the present study suggest that the effect of caecectomy on AAA in geese was dependent on the feedstuff assayed, and it was better to use caecectomised poultry for AAA assessment.

Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) stimulates primitive and definitive erythropoiesis in mouse embryos expressing hGM-CSF receptors but not erythropoietin receptors

Although erythropoietin (EPO) and its receptor (EPOR) are crucial for the proliferation, survival, and terminal differentiation of erythroid progenitors, it remains to be elucidated whether EPOR-unique signaling is required for erythropoiesis. To address this issue, human granulocyte-macrophage colony-stimulating factor (hGM-CSF) receptor (hGMR)-transgenic mice and heterozygous EPOR mutant mice were crossed by in vitro fertilization. In methylcellulose clonal culture of fetal liver (FL) cells of generated hGMR-expressing EPOR(-/-) embryos at embryonic day (E) 12.5 of gestation, hGM-CSF stimulated erythroid colony formation under serum-containing and serum-free conditions. Analysis of globin expression in individual erythrocyte-containing colonies formed from E12.5 FL cells showed that hGM-CSF supports primitive and definitive erythropoiesis even in EPOR(-/-) embryos. In comparison of activities between hGM-CSF and EPO in hGMR-expressing EPOR(+/+) embryos, the 2 substances supported the formation of similar numbers of erythroid colonies in clonal culture of E12.5 FL cells; enhanced adult, but not embryonic, globin synthesis; and induced increase of GATA-1 expression and decrease of erythroid Kruppel-like factor and cMyb expression in the FL cells. On the other hand, in E8.0 yolk sac erythropoiesis, both substances had a similar effect on erythroid colony formation, but hGM-CSF induced an increase of beta-major globin expression, while EPO did not. All together, the results of the present study demonstrated that hGM-CSF can stimulate the proliferation and differentiation of primitive and definitive erythroid cells independently of EPOR signal if they express hGMR, and the activity is comparable to that of EPO in definitive, but not primitive, erythropoiesis.

A phase I trial of AUC-directed carboplatin with infusional doxorubicin and ifosfamide plus G-CSF in patients with advanced gynecologic malignancies

The effect of the addition of G-CSF to carboplatin, ifosfamide and doxorubicin (CIA) at the maximally tolerated dose (MTD) was studied in a phase I clinical trial. Nine patients with incurable solid tumors were treated: six endometrial and epithelial ovarian cancers, one colon cancer with pelvic masses and two unknown primary cancers. The carboplatin dose was calculated using the Calvert formula and administered in a standard 30-min intravenous infusion. The initial carboplatin dose was AUC 4.0 mg/ml per min. Fixed doses of ifosfamide (1.25 g/m2 per day), mesna (1.0 g/m2 per day, and doxorubicin (15 mg/m2 per day) were combined and given as a 4-day continuous intravenous infusion in an attempt to decrease nonhematologic toxicity. The dose-limiting toxicity of CIA was myelosuppression, mainly neutropenia and thrombocytopenia. Nonhematologic toxicities were hemorrhagic cystitis, weakness, fatigue, and nausea and vomiting. The MTD for CIA was established at the first dose level of carboplatin (4.0 mg/ml per min). Following this, G-CSF was added to the regimen in an unsuccessful effort to escalate the carboplatin dose. Free and total carboplatin pharmacokinetics were determined using flameless atomic absorption spectroscopy. There was one complete response and one partial response among eight evaluable patients. Both responding patients had advanced ovarian cancer. We conclude that carboplatin dose intensification beyond an AUC of 4.0 mg/ml per min is not made feasible by the addition of G-CSF to infusional doxorubicin and ifosfamide in patients with advanced gynecologic cancer.

Chemoprevention of human actinic keratoses by topical 2-(difluoromethyl)-dl-ornithine

Alpha-2-(Difluoromethyl)-dl-ornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, has been shown to suppress skin carcinogenesis in murine models after oral or topical administration. We designed a randomized, placebo-controlled study using a topical hydrophilic ointment formulation with or without 10% (w/w) DFMO. Forty-eight participants with moderate-severe actinic keratoses (AKs) on their forearms (i.e., at least 10 well-circumscribed lesions on the lateral surface) completed a 1-month run-in on placebo ointment. Before randomization, all lateral forearm AKs were circled, counted, photographed, and skin biopsies were obtained for DFMO and polyamine levels. Then participants were randomized to receive DFMO ointment on the right versus the left forearm and placebo hydrophilic ointment on the contralateral forearm twice daily for 6 months. DFMO was not detected in the blood of any subject, and there were no systemic toxicities. None of a subsample of 17 placebo forearms had measurable concentrations of DFMO, whereas 13 of the corresponding DFMO-treated forearms had high DFMO skin levels. As compared with placebo, the 6-month DFMO treatment caused a 23.5% reduction in the number of AKs (P = 0.001) as well as significant suppression of AK biopsy spermidine levels (26%; P = 0.04). Seven of the 48 (14.6%) participants experienced severe (2; 4.2%) or moderate (5; 10.4%) inflammatory reactions on their DFMO-treated arms which required dosing modification. Topical DFMO for 6 months can reduce the number of AK lesions and skin spermidine concentrations in high-risk participants and deserves additional study as a skin cancer chemopreventive agent.

Exclusive expression of G-CSF receptor on myeloid progenitors in bone marrow CD34+ cells

Although granulocyte colony-stimulating factor (G-CSF) has been reported to act on cells of neutrophilic lineage, the administration of G-CSF to induce the mobilization of various haematopoietic progenitors into the circulation. We analysed the expression of receptors for G-CSF (G-CSFR) on human bone marrow and G-CSF-mobilized peripheral blood CD34+ cells, and examined the proliferation and differentiation capabilities of sorted CD34+G-CSFR+ and CD34+G-CSFR- cells using methylcellulose clonal culture. Flow cytometric analysis showed that G-CSFR was expressed on 14.9 +/- 4.9% of bone marrow CD34+ cells, most of which were included in CD34+CD33+ and CD34+CD38+ cell fractions. In clonal cultures, CD34+G-CSFR+ cells produced only myeloid colonies, whereas CD34+G-CSFR- cells produced erythroid bursts, megakaryocyte and multilineage colonies. When incubated with the cytokine cocktail for 5 d, CD34+G-CSFR- cells generated CD34+G-CSFR+ myeloid progenitors. In G-CSF-mobilized peripheral blood, CD34+ cells contained 10.8 +/- 5.8% of G-CSFR+ cells, most of which were also myeloid progenitors, although CD34+G-CSFR- cells contained a substantial number of myeloid progenitors. These results indicated that the expression of G-CSFR on CD34+ cells is restricted to myeloid progenitors, suggesting that the specific activity of G-CSF on myelopoiesis depends on the exclusive expression of its receptor on myeloid progenitors, and that the mobilization of various haematopoietic progenitors is not a direct effect of G-CSF in humans.

Differential effects of human granulocyte colony-stimulating factor (hG-CSF) and thrombopoietin on megakaryopoiesis and platelet function in hG-CSF receptor-transgenic mice

Granulocyte-colony stimulating factor (G-CSF) has been found to act on the neutrophilic lineage. We recently showed that human G-CSF (hG-CSF) has effects similar to early-acting cytokines such as interleukin-3 (IL-3) in the development of multipotential hematopoietic progenitors in transgenic (Tg) mice expressing receptors (R) for hG-CSF. In the present study, we examined the effects of hG-CSF on more mature hematopoietic cells committed to megakaryocytic lineage in these Tg mice. The administration of hG-CSF to the Tg mice increased the numbers of both platelets in peripheral blood and megakaryocytes in the spleen, indicating that hG-CSF stimulates megakaryopoiesis in the Tg mice in vivo. The stimulatory effect of hG-CSF was also supported by the results of studies in vitro. hG-CSF supported megakaryocyte colony formation in a dose-dependent fashion in clonal cultures of bone marrow cells derived from the Tg mice. Direct effects of hG-CSF on megakaryocytic progenitors in the Tg mice were confirmed by culture of single-cell sorted from bone marrow cells. hG-CSF showed a stronger effect on maturation of megakaryocytes in the Tg mice than that of IL-3 alone, but weaker than that of TPO alone. In addition, hG-CSF induced phosphorylation of STAT3 but not Jak2 or STAT5, while TPO induced phosphorylation of both. In contrast to TPO, hG-CSF did not enhance ADP-induced aggregation. Thus, hG-CSF has a wide variety of functions in megakaryopoiesis of hG-CSFR-Tg mice, as compared with other megakaryopoietic cytokines, but the activity of hG-CSF in megakaryocytes and platelets does not stand up to a comparison with that of TPO. Specific signals may be required for the full maturation and activation of platelets.

Hepatic differentiation induced by oncostatin M attenuates fetal liver hematopoiesis

Embryonic liver is a transient site for definitive hematopoiesis. Along with maturation of the bone marrow and spleen, hematopoietic cells relocate from the liver to their final destinations while the liver starts organizing its own structure and develops numerous metabolic functions toward adult. Recently, it was demonstrated that the signal exerted by oncostatin M (OSM) through gp130 plays a pivotal role in the maturation process of the liver both in vitro and in vivo. However, the molecular basis underlying the termination of embryonic hematopoiesis remains unknown. In this study, we report that primary culture of fetal hepatic cells from embryonic day 14.5 murine embryos supported expansion of blood cells from Lin-Sca-1(+)c-Kit+ cells, giving rise to myeloid, lymphoid, and erythroid lineages. Of interest, promotion of hepatic development by OSM and glucocorticoid strongly suppressed in vitro hematopoiesis. Consistent with these results, hepatic culture from the embryonic day 18.5 liver no longer supported hematopoiesis. These data together with the previous observations suggest that the signals exerted by OSM and glucocorticoid induce hepatic differentiation, which in turn terminate embryonic hematopoiesis and promote relocation of hematopoietic cells.

[New diterpenoids, isodoternifolins A and B, from Isodon ternifolius]

Two new diterpenoids, named isodoternifolin A and B, together with seven known compounds were isolated from the ethanol extract of dried stems and leaves of Isodon ternifolius (D. Don) Kudo. Their structures were determined as 7 beta-hydroxy-6 beta, 11 alpha, 15 beta-triacetoxy-7 alpha, 20-epoxyentkaur-16-ene (1) and 6 beta, 7 beta, 15 beta-trihydroxy-11 alpha-acetoxy-7 alpha, 20-epoxy-entkaur-16-ene (2) by chemical and spectral evidence.

Human granulocyte colony-stimulating factor (G-CSF) stimulates the in vitro and in vivo development but not commitment of primitive multipotential progenitors from transgenic mice expressing the human G-CSF receptor

Granulocyte colony-stimulating factor (G-CSF) stimulates the proliferation and restricted differentiation of hematopoietic progenitors into neutrophils. To clarify the effects of G-CSF on hematopoietic progenitors, we generated transgenic (Tg) mice that had ubiquitous expression of the human G-CSF receptor (hG-CSFR). In clonal cultures of bone marrow and spleen cells obtained from these mice, hG-CSF supported the growth of myelocytic as well as megakaryocytic, mast cell, mixed, and blast cell colonies. Single-cell cultures of lineage-negative (Lin-)c-Kit+Sca-1(+) or Sca-1(-) cells obtained from the Tg mice confirmed the direct effects of hG-CSF on the proliferation and differentiation of various progenitors. hG-CSF also had stimulatory effects on the formation of blast cell colonies in cultures using 5-fluorouracil-resistant hematopoietic progenitors and clone-sorted Lin-c-Kit+Sca-1(+) primitive hematopoietic cells. These colonies contained different progenitors in proportions similar to those obtained when mouse interleukin-3 was used in place of hG-CSF. Administration of hG-CSF to Tg mice led to significant increases in spleen colony-forming and mixed/blast cell colony-forming cells in bone marrow and spleen, but did not alter the proportion of myeloid progenitors in total clonogenic cells. These results show that, when functional G-CSFR is present on the cell surface, hG-CSF stimulates the development of primitive multipotential progenitors both in vitro and in vivo, but does not induce exclusive commitment to the myeloid lineage.

13-cis-retinoic acid or all-trans-retinoic acid plus interferon-alpha in recurrent cervical cancer: a Southwest Oncology Group phase II randomized trial

PURPOSE

Preclinical and clinical data support the study of retinoids and interferon-alpha (IFN-alpha) in advanced squamous cell carcinoma of the uterine cervix (SCC). This phase II randomized trial of the Southwest Oncology Group sought to estimate the response rate for IFN-alpha plus either 13-cis-retinoic acid (13cRA) or all-trans-retinoic acid (ATRA) in women with recurrent cervical SCC.

PATIENTS AND METHODS

Eligibility for this trial required bidimensionally measurable locally recurrent or metastatic squamous or adenosquamous carcinoma of the uterine cervix; SWOG performance status of </=2; no prior interferon, retinoids, or chemotherapy (except as radiation sensitization). All but two patients were previously treated with surgery, radiation therapy, or both. After randomization, patients received IFN-alpha-2A (subcutaneous injection; 3 x 10(6) units/m2/day) plus either 13cRA (1 mg/kg/day orally) or ATRA (150 mg/m2/day orally) in two equally divided doses.

RESULTS

Total enrollment was 63 patients, 21 in the ATRA arm, 42 in the 13cRA arm. Three patients were ineligible, 1 in the ATRA arm, 2 in the 13cRA arm. Each arm had 1 patient who received no assigned treatment and was not evaluated for response or toxicity. The ATRA/IFN-alpha response rate was 5% (1/19; 95% confidence interval = 0.1-26%), consisting of 1 partial response lasting 4 weeks. The 13cRA/IFN-alpha response rate was 8% (3/39; 95% confidence interval = 2-21%), consisting of 3 partial responses lasting 17, 22, and 24 weeks, respectively. All confirmed responses were partial. One additional unconfirmed partial response occurred in the 13cRA arm. Both regimens were generally well-tolerated and produced toxicities (principally malaise and fatigue) associated with each constituent agent's known single-agent side effects.

CONCLUSION

Based upon the results of this study, neither regimen can be recommended for further study in patients previously treated with radiation therapy.

Stimulation of mouse and human primitive hematopoiesis by murine embryonic aorta-gonad-mesonephros-derived stromal cell lines

We report here on a novel stromal cell line, AGM-S3, derived from the aorta-gonad-mesonephros (AGM) region of a 10.5 days postcoitum (dpc) mouse embryo. The AGM-S3 cells promoted production of hematopoietic progenitors and day-12 spleen colony-forming cells from Lin-c-Kit+Sca-1(+) murine primitive hematopoietic cells. They also supported for 6 weeks generation of human multipotential progenitors from cord blood CD34(+)CD38(-) primitive hematopoietic cells. Human long-term repopulating hematopoietic stem cells (LTR-HSC) with the potential to reconstitute hematopoiesis in NOD/SCID mice were maintained on AGM-S3 cells for at least 4 weeks. Flow cytometric analysis showed that CD13, vascular cellular adhesion molecule-1, and Sca-1 were expressed on AGM-S3 cells. Because stem cell factor, interleukin-6 (IL-6), and oncostatin M, but not IL-3, IL-11, leukemia- inhibitory factor, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, thrombopoietin, and Flk2 ligand were detected in reverse transcription-polymerase chain reaction analysis of AGM-S3 cells, the cells seem to express species-cross reactive molecule(s) other than the cytokines examined and which act on primitive hematopoietic progenitor/stem cells. This cell line is expected to elucidate molecular mechanisms regulating early hematopoiesis and pave the way for developing strategies for expansion of human transplantable HSC.

Involvement of polyamines in selenomethionine induced apoptosis and mitotic alterations in human tumor cells

The efficacy of dietary selenium supplementation is currently being evaluated in intervention trials. However, the biological mechanisms underlying the cancer chemopreventive effects of selenium supplementation have yet to be elucidated. Selenium metabolism and polyamine biosynthesis are linked in their common requirement for S-adenosylmethionine. Selenomethionine was the predominant form of selenium in the dietary supplement, therefore we evaluated the anti-tumorigenic effects of selenomethionine. We found that selenomethionine inhibited tumor growth (both in A549 lung and HT29 colon cancer cells) in a dose-dependent manner. At 24 and 72 h, polyamine content of A549 and HT29 cancer cell lines was decreased at doses that inhibited 50% of normal growth. Selenomethionine treatment induced apoptosis in both cancer cell lines. Exogenous spermine administration, which replenishes intracellular polyamine levels, prevented selenomethionine induced apoptosis. Selenomethionine administration to the cancer cell lines increased the number of cells in metaphase. This cell cycle effect appeared to be reversed with the co-administration of selenomethionine and spermine. These data suggested that at least part of the anti-carcinogenic effects of selenium supplementation might be due to a depletion in polyamine levels. This depletion of polyamines leads to an induction in apoptosis and perturbations in the cell cycle.

Disposition and metabolism of topically administered alpha-tocopherol acetate: a common ingredient of commercially available sunscreens and cosmetics

Skin cancers are a serious health problem in the United States. One common method of skin cancer primary prevention is use of sunscreens. Research has been conducted to ascertain the role of active ingredients of sunscreen products in photoprotection and possible carcinogenesis. In contrast, little is known about the "other ingredients", listed or unlisted, on sunscreen product labels. One such ingredient is vitamin E. usually in the form of alpha-tocopherol acetate. Results of recent studies of skin carcinogenesis in an ultraviolet (UV) B mouse carcinogenesis model suggest that topically applied alpha-tocopherol acetate does not prevent and, under some conditions, enhances skin cancer development and growth, whereas the free unesterified from of alpha-tocopherol significantly reduces experimental UVB carcinogenesis. We have performed a Phase II cancer prevention study to evaluate whether topically applied alpha-tocopherol acetate is absorbed in human skin and metabolizes to the free or other forms. In this double-blind study, 19 men and women > 30 years of age who had at least three actinic keratoses on their forearms were randomly assigned to apply alpha-tocopherol acetate (125 mg/g) or difluoromethylornithine cream to their arms twice daily for three months. Blood samples and photographs and punch biopsies of actinic keratoses were obtained before and at the end of the study (Month 4). Plasma and skin concentrations of free alpha-tocopherol, alpha-tocopherol acetate, and gamma-tocopherol were analyzed by high-performance liquid chromatography at Month 4. The results of this report focus only on data obtained from the 11 participants randomized to the alpha-tocopherol acetate arm of the study. Topically applied alpha-tocopherol acetate was substantially absorbed in skin, with no evidence of conversion within skin to its unesterified form (i.e., free alpha-tocopherol). There was no evidence of systemic availability or biotransformation of topically applied alpha-tocopherol acetate. In summary, we have determined that alpha-tocopherol acetate is not metabolized to the free form of alpha-tocopherol in plasma or skin.

Cardiotoxicity in the SCID mouse following administration of doxorubicin and cyclosporin A

Multiple myeloma is a plasma cell malignancy which is generally incurable in spite of a high initial response to chemotherapy. Relapsing disease commonly heralds an increase in the incidence of drug resistance which is often mediated by the product of the MDR-1 gene, P-glycoprotein (Pgp). One approach to modulating drug resistance due to Pgp overexpression has involved the use of agents known as chemomodulators which inhibit its function. We have developed a human xenograft model of multiple myeloma using the SCID mouse to evaluate the efficacy and toxicities of new MDR-1 chemomodulators. Cyclosporin A (CsA) is a widely used immunosuppressant which has been demonstrated to be a potent inhibitor of Pgp in vitro at concentrations which are clinically achievable. Preliminary studies revealed an acute toxicity in our SCID model which was associated with the combination of CsA and doxorubicin, and which was not observed with either drug alone, nor with cremaphor, the vehicle for CsA. In the current study, non-tumor bearing SCID mice were dosed with doxorubicin or the combination of doxorubicin with cremaphor, verapamil or CsA. Animals were sacrificed and tissues harvested for morphologic examination and for HPLC analysis of doxorubicin levels. In all tissues examined, there was a marked increase in tissue levels of doxorubicin when combined with CsA. Results also revealed a higher incidence and severity of myocardial damage in those animals receiving the combination of doxorubicin and CsA than in those receiving other combinations. The elevations in tissue levels observed with doxorubicin and CsA may contribute to the acute toxicities observed in the SCID mouse model.

Reduction in plasma or skin alpha-tocopherol concentration with long-term oral administration of beta-carotene in humans and mice

BACKGROUND

Beta-carotene is one of the most commonly used compounds in clinical trials of chemopreventive agents in various neoplastic diseases. Animal studies, including our own, have documented that dietary beta-carotene can reduce plasma alpha-tocopherol (vitamin E) levels, but few published studies have examined the clinical or pharmacokinetic ramifications of long-term, high-dose beta-carotene regimens on other fat-soluble vitamins such as alpha-tocopherol.

PURPOSE

This study was designed to determine the effects of long-term beta-carotene supplementation on plasma concentrations of alpha-tocopherol in normal human subjects and in an experimental C3H/HeN mouse model.

METHODS

In a double-blind study, 45 normal subjects were randomly assigned to receive 0 (placebo), 15, 30, 45, or 60 mg of oral beta-carotene daily for approximately 9 months. Monthly plasma samples were collected. Thirty-five C3H/HeN mice were fed a basal diet with or without beta-carotene and treated topically with or without alpha-tocopherol, except for the control mice, which received UV radiation for 27 weeks from week 3 to week 30. Plasma and dorsal skin samples were taken after 40 weeks and were analyzed for alpha-tocopherol and/or beta-carotene by high-performance liquid chromatography.

RESULTS

Long-term dietary beta-carotene administration resulted in statistically significant reductions in levels of alpha-tocopherol in the skin and plasma of UV-irradiated mice. In the human study, the decrease in plasma alpha-tocopherol levels was progressive and significant between 6 and 9 months of beta-carotene dosing in all dosage groups. The greatest decrease was observed during the 9th (last) month of dosing, with a decrease of 40% from baseline. All oral beta-carotene doses (15-60 mg/d), however, resulted in similar decreases in steady-state plasma levels of alpha-tocopherol and in only small differences in beta-carotene plasma levels.

CONCLUSION

Long-term oral administration of beta-carotene decreased steady-state plasma concentrations of alpha-tocopherol. The lack of a significant dose-response effect between doses of beta-carotene and alpha-tocopherol plasma levels is not unexpected, given the small differences in steady-state beta-carotene plasma levels in the four beta-carotene dose groups.

IMPLICATIONS

Studies are needed to determine how long-term beta-carotene dosing influences tissue distribution of dietary alpha-tocopherol. Careful surveillance for this and other potentially harmful nutrient interactions should become part of all long-term intervention studies.

The role of serum and tissue pharmacology studies in the design and interpretation of chemoprevention trials

The design and interpretation of chemoprevention trials are challenging tasks. Innovative methodological approaches to these investigations are in initial stages of development. Important pharmacologic issues should be addressed as early as possible in these trials to facilitate the optimal design of large, Phase III, randomized trials. These include determining the optimal dose of the compound and the toxicity profile. Other key areas involve the use of serum concentrations to monitor subject compliance, the evaluation of concentration of the chemopreventive agent in the target tissue, adequate assessment of the drug delivery systems, and the evaluation of the relationship between the dose administered and the serum or tissue concentrations achieved. Whenever possible the investigation of the relationship between serum or tissue concentrations of a chemopreventive agent vs its biologic activity should be determined. Specific examples involving the retinoids and carotenoids are presented.

Pharmacokinetics of N-4-hydroxyphenyl-retinamide and the effect of its oral administration on plasma retinol concentrations in cancer patients

Concurrent with a phase-II trial of 4HPR in patients with various cancers, we studied the plasma pharmacokinetics of both 4HPR and its major metabolite 4MPR as well as the effect of 4HPR administration on plasma retinol concentrations using a simple, specific and sensitive HPLC procedure. Initial estimates of plasma pharmacokinetic parameters after oral administration of 4HPR (300 mg/day) [corrected] in 3 cancer patients were the following: 4HPR, t beta 1/2 = 13.7 hr, AUC = 3.49 micrograms.hr/ml, CL = 56.57 L/hr/m2; 4MPR, t beta 1/2 = 23.0 hr, AUC = 1.15 micrograms.hr/ml, CL = 239.29 L/hr/m2. We also found that oral administration of 4HPR resulted in a rapid, profound and significant reduction in plasma retinol concentrations. The mean plasma retinol concentrations for 9 patients decreased 60% from baseline to below 200 ng/ml within 1-2 weeks of 4HPR dosing initiation. In addition, there was a concurrent, significant reduction in plasma retinol-binding protein levels in these patients. The mechanism whereby 4HPR reduces plasma retinol levels in vivo has not been determined. The addition of 4HPR to pooled human plasma at 37 degrees C in vitro did not reduce endogenous retinol levels, suggesting no direct chemical interaction between these 2 retinoids.

In vitro evaluation of cisplatin interaction with doxorubicin or 4-hydroperoxycyclophosphamide against human gynecologic cancer cell lines

Doxorubicin, cisplatin, and cyclophosphamide are the three drugs most commonly used in the treatment of ovarian cancer, but no effect greater than additivity was observed for any combination of these drugs in the present study. Only a few studies have been reported concerning the degree of their additivity or their best order of sequencing. In our in vitro studies, cisplatin in combination with doxorubicin or 4-hydroperoxycyclophosphamide (4HC) was tested against seven human gynecologic tumor-cell lines in different sequences, using a double-agar layer tissue-culture system. Drug interactions with respect to inhibition of tumor clonogenicity were evaluated by isobologram and fractional survival methods. Doxorubicin and 4HC were sequenced simultaneously and at 1, 6 and 24 h after cisplatin, and cisplatin was sequenced at 1, 6 and 24 h after 4HC. The isobolograms constructed for doxorubicin or 4HC plus cisplatin revealed strict additivity between these agents against ovarian cancer clonogenicity. Both doxorubicin and 4HC showed the greatest additivity when used simultaneously and at 1 h vs 6 or 24 h after cisplatin. Although the mechanisms by which these sequencing effects occur are unknown, these studies provide new leads for the design of clinical trials with combinations of these three agents.

Potentiation of platinum analogue cytotoxicity by hyperthermia

Carboplatin and iproplatin, two new analogues of cisplatin, appear to have comparable activity in the treatment of advanced ovarian cancer, but minimal nephro- and neurotoxicities. Hyperthermia can potentiate the cytoxicity of cisplatin in vitro and in vivo, but systemic treatment with the combination has proven unsafe in patients. To provide the rationale for an alternative approach, we evaluated the relative degree of additivity between hyperthermia and the three platinum analogues in vitro against a human ovarian adenocarcinoma cell line, UACC-66. All drug and heat treatments were simultaneous for 1 h. Platinum analogue concentrations covered a five-log range from 0.001 to 100 micrograms/ml and hyperthermia temperatures included 38.5 degrees, 40 degrees, 41.5 degrees, and 43 degrees C. A tumor clonogenic assay was used to quantitate heat-drug interactive effects against the UACC-66 cells, and statistical analysis was performed using the median-effect equation of Chou. When combined with heat, the in vitro concentrations of the three platinum analogues were between 5% and 25% of those required at 37 degrees C to inhibit 50%-70% of the UACC-66 tumor colony-forming units. For each drug when combined with heat, a 3 degrees C incremental increase in temperature (i.e., from 37 degrees C to 40 degrees C or from 40 degrees C to 43 degrees C) was associated with a ten-fold decrease in ID50 drug concentration. We conclude that the synergistic effects of both carboplatin and iproplatin with hyperthermia at all temperatures above 37 degrees C provide a rationale for design of clinical trials in patients with ovarian cancer using these hyperthermia-drug combinations.

Analysis and stability of retinol in plasma

A simple, precise, and specific high-performance liquid chromatography (HPLC) method was developed for the simultaneous measurement of retinol (ROH), 13-cis-retinoic acid (13-cRA), and 4-oxo-13-cRA. The average recovery of ROH from serum or plasma was 95%, and the precision of the assay was less than 5%. With this HPLC method, a series of studies was carried out to evaluate the stability of ROH in various matrices. ROH was stable under our HPLC assay conditions as well as in plasma- and in serum-enriched culture media; however, ROH was not stable in aqueous matrices. Serum or heparinized plasma may be routinely used for measurement of ROH concentrations, providing EDTA, oxalate, and citrate are not used as anticoagulants. Because of ROH stability, blood samples can be kept on ice in the dark for at least 24 hours prior to separation of plasma. In addition, plasma samples containing ROH can be stored for up to 1 year at -20 degrees C without loss of stability.