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The effect of cyclosporine on ornithine decarboxylase induction with mitogens, antigens, and lymphokines.

Ornithine decarboxylase (ODC) is the initial enzyme in polyamine synthesis. An increase in ODC activity is associated with increased RNA, DNA, and protein synthesis. We have used the induction of ODC by mitogens and alloantigens in human peripheral blood lymphocytes as an intracellular marker of protein synthesis and lymphocyte activation. The immunosuppressive agent cyclosporine was found to inhibit both the mitogen and alloantigen stimulated induction of ODC in lymphocytes in a manner that parallels inhibition of subsequent 3H-thymidine incorporation. When purified T lymphocytes were stimulated with mitogen alone, minimal ODC activity was detected. The addition of 5% monocytes, human Interleukin-1 (IL-1), or T cell growth factor (IL-2) enhanced mitogen-induced ODC activity in T lymphocytes 4-10-fold. Cyclosporine inhibited the induction of ODC when T lymphocytes were combined with monocytes or growth factors. We conclude that (1) the induction of ODC in human lymphocytes by mitogen and alloantigen is inhibited in the presence of cyclosporine; (2) the induction of ODC activity in purified T lymphocytes requires the presence of both mitogen and monocytes or their products; (3) IL-1 and IL-2 can supplement for monocytes and augment the phytohemagglutinin induction of ODC in T lymphocytes; and (4) cyclosporine inhibits ODC induction in T lymphocytes stimulated with mitogen in the added presence of monocytes, IL-1, or IL-2. The inhibition of ODC induction and polyamine synthesis by cyclosporine adds insight into its mode of action on the mechanisms involved in early T cell activation.

Cyclosporins↗

Inhibition of Caenorhabditis elegans vulval induction by gap-1 and by let-23 receptor tyrosine kinase.

During induction of the Caenorhabditis elegans hermaphrodite vulva, a signal from the anchor cell activates the LET-23 epidermal growth factor receptor (EGFR)/LET-60 Ras/MPK-1 MAP kinase signaling pathway in the vulval precursor cells. We have characterized two mechanisms that limit the extent of vulval induction. First, we found that gap-1 may directly inhibit the LET-60 Ras signaling pathway. We identified the gap-1 gene in a genetic screen for inhibitors of vulval induction. gap-1 is predicted to encode a protein similar to GTPase-activating proteins that likely functions to inhibit the signaling activity of LET-60 Ras. A loss-of-function mutation in gap-1 suppresses the vulvaless phenotype of mutations in the let-60 ras signaling pathway, but a gap-1 single mutant does not exhibit excess vulval induction. Second, we found that let-23 EGFR prevents vulval induction in a cell-nonautonomous manner, in addition to its cell-autonomous role in activating the let-60 ras/mpk-1 signaling pathway. Using genetic mosaic analysis, we show that let-23 activity in the vulval precursor cell closest to the anchor cell (P6.p) prevents induction of vulval precursor cells further away from the anchor cell (P3.p, P4.p, and P8.p). This result suggests that LET-23 in proximal vulval precursor cells might bind and sequester the inductive signal LIN-3 EGF, thereby preventing diffusion of the inductive signal to distal vulval precursor cells.

Amino Acid Sequence↗

Mimicry in primary rat hepatocyte cultures of the in vivo perivenous induction by phenobarbital of cytochrome P-450 2B1 mRNA: role of epidermal growth factor and perivenous oxygen tension.

Treatment of male rats with phenobarbital (PB) results in a perivenous and mid-zonal pattern of cytochrome P-450 (CYP)2B1 mRNA expression within the liver acinus. The mechanism of this zonated induction is still poorly understood. In this study sinusoidal gradients of oxygen and epidermal growth factor (EGF) besides those of the pituitary-dependent hormones growth hormone (GH), thyroxine (T4), and triiodothyronine (T3) were considered to be possible determinants for the zonated induction of the CYP2B1 gene in liver. Moreover, heme proteins seem to play a key role in oxygen sensing. Therefore, the influence of arterial (16% O2) and venous (8% O2) oxygen tension (pO2), and of the heme synthesis inhibitors CoCl2 and desferrioxamine (DSF) on PB-dependent CYP2B1 mRNA induction as well as the repression by EGF and, for comparison, by GH, T4, and T3, of the induction under arterial and venous pO2 were investigated in primary rat hepatocytes. Within 3 days, phenobarbital induced CYP2B1 mRNA to maximal levels under arterial pO2 and to about 40% of maximal levels under venous pO2. CoCl2 annihilated induction by PB under both oxygen tensions, whereas desferrioxamine and heme abolished the positive modulation by O2, suggesting that heme is a necessary component for O2 sensing. EGF suppressed CYP2B1 mRNA induction by PB only under arterial but not under venous pO2, whereas GH, T4, and T3 inhibited induction under both arterial and venous pO2. Thus, in hepatocyte cultures, an O2 gradient in conjunction with EGF mimicked the perivenous induction by PB of the CYP2B1 gene observed in the liver in vivo.

Animals↗

Interleukin-1beta, Src- and non-Src tyrosine kinases, and nitric oxide synthase induction in rat aorta in vitro.

We studied the potential roles for endogenous interleukin-1beta (IL-1beta) and for several signaling pathways in the spontaneous induction in vitro of inducible nitric oxide synthase (iNOS) in endothelium-denuded rat aorta rings. Added IL-1beta augmented, whereas the IL-1beta receptor antagonist IL-1ra blocked, spontaneous iNOS induction. Furthermore, increases in IL-1beta mRNA preceded those of iNOS mRNA. Mitogen-activated protein kinase kinase and phosphatidyl inositol 3' kinase inhibition did not block iNOS induction, whereas nuclear factor kappaB inhibition did. The sarcoma virus tyrosine kinase (Src) family-selective inhibitor 4-amino-5(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP1) blocked the upregulation of IL-1beta mRNA and the subsequent induction of iNOS but not the induction of iNOS stimulated by exogenously added IL-1beta. In contrast, the non-Src inhibitors TP 47/AG 213 and genistein and the tyrosine phosphatase inhibitor vanadate did not affect the spontaneous upregulation of IL-1beta mRNA but blocked both the IL-1beta-mediated and spontaneous induction of iNOS. We conclude that 1) the upregulation of tissue IL-1beta, via a signaling pathway involving a Src family kinase, plays a key role in rat vascular iNOS induction and 2) non-Src tyrosine kinases play roles downstream from IL-1beta for iNOS induction.

Animals↗

No clinically relevant CYP3A induction with the dual angiotensin-converting enzyme/neutral endopeptidase inhibitor, M100240.

M100240, an acetate thioester of MDL 100,173, is a dual angiotensin-converting enzyme/neutral endopeptidase inhibitor currently in Phase II development. M100240 and MDL 100,173 were evaluated in an in vitro cytochrome P450 human hepatocyte model for enzyme induction. Although a dose-dependent CYP3A induction was observed between 10 and 100 microM, at 1 microM-which approaches clinically relevant plasma concentrations in humans-there was no evidence of CYP3A induction. An in vitro reporter gene assay also demonstrated the CYP3A isozyme induction potential of M100240 and MDL 100,173 with an EC(50) approximately 1.5 microM. The present study evaluated the potential for CYP3A enzyme induction in healthy volunteers. In an open-label, single-sequence, replicate-design study using midazolam as a CYP3A probe in 13 healthy volunteers, we found no evidence of clinically relevant CYP3A induction after multiple-dose administration of 50 mg M100240 orally once daily for 15 days. Single and multiple doses of M100240 increased the midazolam AUC(0-24 h) about 1.6-fold compared to baseline, suggesting weak CYP3A inhibition. Concomitant administration of midazolam and M100240 was generally safe and well tolerated. Although in vitro CYP3A induction at exposures in excess of clinically relevant human plasma concentrations has been demonstrated, there is no clinical evidence of CYP3A induction with M100240 administration at proposed therapeutic doses.

Adolescent↗

Nuclear integration of positive Dpp signals, antagonistic Wg inputs and mesodermal competence factors during Drosophila visceral mesoderm induction.

Tissue induction during embryonic development relies to a significant degree on the integration of combinatorial regulatory inputs at the enhancer level of target genes. During mesodermal tissue induction in Drosophila, various combinations of inductive signals and mesoderm-intrinsic transcription factors cooperate to induce the progenitors of different types of muscle and heart precursors at precisely defined positions within the mesoderm layer. Dpp signals are required in cooperation with the mesoderm-specific NK homeodomain transcription factor Tinman (Tin) to induce all dorsal mesodermal tissue derivatives, which include dorsal somatic muscles, the dorsal vessel and visceral muscles of the midgut. Wingless (Wg) signals modulate the responses to Dpp/Tin along anteroposterior positions by cooperating with Dpp/Tin during dorsal vessel and somatic muscle induction while antagonizing Dpp/Tin during visceral mesoderm induction. As a result, dorsal muscle and cardiac progenitors form in a pattern that is reciprocal to that of visceral muscle precursors along the anteroposterior axis. Our present study addresses how positive Dpp signals and antagonistic Wg inputs are integrated at the enhancer level of bagpipe (bap), a NK homeobox gene that serves as an early regulator of visceral mesoderm development. We show that an evolutionarily conserved bap enhancer element requires combinatorial binding sites for Tin and Dpp-activated Smad proteins for its activity. Adjacent binding sites for the FoxG transcription factors encoded by the Sloppy paired genes (slp1 and slp2), which are direct targets of the Wg signaling cascade, serve to block the synergistic activity of Tin and activated Smads during bap induction. In addition, we show that binding sites for yet unknown repressors are essential to prevent the induction of the bap enhancer by Dpp in the dorsal ectoderm. Our data illustrate how the same signal combinations can have opposite effects on different targets in the same cells during tissue induction.

Animals↗

Reinvestigation of the role of the optic vesicle in embryonic lens induction.

The induction of the lens by the optic vesicle in amphibians is often cited as support for the view that a single inductive event can lead to determination in a multipotent tissue. This conclusion is based on transplantation experiments whose results indicate that many regions of embryonic ectoderm which would normally form epidermis can form a lens if brought into contact with the optic vesicle. Although additional evidence argues that during normal development other tissues, acting before the optic vesicle, also contribute to lens induction, it is still widely held, on the basis of these transplantation experiments, that the optic vesicle alone can elicit lens formation in ectoderm. While testing this conclusion by transplanting optic vesicles beneath ventral ectoderm in Xenopus laevis embryos, it became apparent that contamination of optic vesicles by presumptive lens ectoderm cells can generate lenses in these experiments, illustrating the need for adequate host and donor marking procedures. Since previous studies rarely used host and donor marking, it was not clear whether they actually demonstrated that the optic vesicle can induce lenses. Using careful host and donor marking procedures with horseradish peroxidase as a lineage tracer, we show that the optic vesicle cannot stimulate lens formation in neurula- or gastrula-stage ectoderm of Xenopus laevis. Since the general conclusion that the optic vesicle is sufficient for lens induction rests on studies in many organisms, we felt it was important to begin to test this conclusion in other amphibians as well. Similar experiments were therefore performed with Rana Palustris embryos, since it was in this organism that optic vesicle transplant studies had originally argued that this tissue alone can cause lens induction. Under conditions similar to those used in the original report, but with careful controls to assess the origin of lenses in transplants, we found that the optic vesicle alone cannot elicit lens formation. Our data lead us to propose that the optic vesicle in amphibians is not generally sufficient for lens induction. Instead, we argue that lens induction occurs by a multistep process in which an essential phase in lens determination occurs as a result of inductive interactions preceding contact of ectoderm with the optic vesicle.

Animals↗

Features of embryonic induction.

The patterned distribution of different organs in the amphibian embryo begins with the establishment of two domains, the animal and vegetal regions, that differ in developmental potency. Differences amplify as inductive interactions occur across boundaries between areas of different potency. Embryonic induction establishes a temporally and spatially dynamic area of developmental potency - a morphogenetic field. The final arrangement and differentiation of cell types within the field emerge from subsequent interactions occurring primarily within the field. These principles are illustrated in a review of the induction of the lens and the heart. Recent studies show that the induction of the lens of the eye and the induction of the heart begin early in development. Most of lens inductions occurs before the formation of the optic vesicle, and the heart appears to be part of a complex of dorsal structures whose formation is dependent upon the establishment of the dorsoventral axis. Suppressive as well as inductive tissue interactions occur during the determination of both of these organs, affecting their position and time of appearance. The complex processes of induction defined by the past nine decades of experimental work present many challenging questions that can now be addressed, especially in terms of the molecular events, cellular behaviour and regulatory physiology of the responding tissue.

Animals↗

glp-1 and inductions establishing embryonic axes in C. elegans.

Two successive inductions specify blastomere identities, that is complex cell lineages and not specific tissues, in a major part of the early C. elegans embryo. The first induction acts along the anterior-posterior axis of the embryo and the second along the left-right axis. During the first induction a specific lineage program is induced in the posterior of the two AB blastomeres present in the four cell embryo. During the second induction, almost all of the left-right differences of the embryo are specified by interactions between a single signalling blastomere, MS, and the AB blastomeres that surround it. In both cases the inductions break the equivalence of pairs of blastomeres. The inductions correlate with the cell-cell contacts to the inducing blastomeres. The stereotype cleavage patterns of the early embryo results in invariant cell-cell contacts that guarantee the specificity of the inductions. Both inductions are affected in embryos mutant for glp-1 suggesting that in both cases glp-1 is involved in the reception of the signal.

Animals↗

Establishment of left-right asymmetry in the Caenorhabditis elegans embryo: a multistep process involving a series of inductive events.

Bilateral pairs of blastomeres derived from the founder cell AB, the anterior blastomere of the 2-cell stage, in the Caenorhabditis elegans embryo are initially equivalent in their developmental potential. Recently, we showed that an induction at the 12-cell stage by a blastomere called MS is necessary to establish the differences between left and right pairs of blastomeres in the anterior part of the embryo. Further analysis of the process of creating left-right asymmetry reveals that the induction at the 12-cell stage is only the first of a series of inductions establishing the left-right asymmetry of the embryo. We describe here two further inductions that create additional asymmetries in the posterior part of the embryo. One induction occurs at the 24-cell stage among AB descendants themselves. This induction is restricted to the left side of the embryo as a consequence of the fate changes induced by MS at the 12-cell stage. The second induction requires again blastomeres of the MS lineage and also occurs around the 24-cell stage. Together these inductions establish the fate differences observed in the development of left-right pairs of blastomeres in the embryo.

Animals↗

Induction of the epibranchial placodes.

The cranial sensory ganglia, in contrast to those of the trunk, have a dual embryonic origin arising from both neurogenic placodes and neural crest. Neurogenic placodes are focal thickenings of ectoderm, found exclusively in the head of vertebrate embryos. These structures can be split into two groups based on the positions that they occupy within the embryo, dorsolateral and epibranchial. The dorsolateral placodes develop alongside the central nervous system, while the epibranchial placodes are located close to the top of the clefts between the branchial arches. Importantly, previous studies have shown that the neurogenic placodes form under the influence of the surrounding cranial tissues. In this paper, we have analysed the nature of the inductive signal underlying the formation of the epibranchial placodes. We find that epibranchial placodes do not require neural crest for their induction, but rather that it is the pharyngeal endoderm that is the source of the inductive signal. We also find that, while cranial ectoderm is competent to respond to this inductive signal, trunk ectoderm is not. We have further identified the signalling molecule Bmp7 as the mediator of this inductive interaction. This molecule is expressed in a manner consistent with it playing such a role and, when added to ectoderm explants, it will promote the formation of epibranchial neuronal cells. Moreover, the Bmp7 antagonist follstatin will block the ability of pharyngeal endoderm to induce placodal neuronal cells, demonstrating that Bmp7 is required for this inductive interaction. This work answers the long standing question regarding the induction of the epibranchial placodes, and represents the first elucidation of an inductive mechanism, and a molecular effector, underlying the formation of any primary sensory neurons in higher vertebrates.

Animals↗

Effects of calcium antagonists on cyclic AMP phosphodiesterase induction in Dictyostelium discoideum.

Previous studies have suggested that cyclic GMP and/or Ca2+ might function as second messengers in the induction by exogenous cyclic AMP of the cyclic AMP phosphodiesterase (PD) in Dictyostelium discoideum. To assess further the role of Ca2+ in PD induction we examined the effect on this process of a number of putative Ca2+-channel blockers. At relatively low micromolar concentrations, TMB-8, nicardipine, nifedipine, diltiazem and verapamil all altered cell shape and inhibited PD induction in a similar dose-dependent fashion. Concentrations of these drugs that abolished PD induction had no effect on cell viability; however, higher concentrations reduced viability and caused cell lysis. All effects of these compounds on the cells were antagonized at least partially by 5-10 mM-Ca2+. Other cations tested were considerably less effective. Like the organic inhibitors, La3+ also altered cell shape, inhibited PD induction and reduced cell viability at elevated concentrations, but its effect on the cells appeared to be more complex. Inhibition of PD induction by the organic antagonists could not be attributed solely to an impaired uptake of extracellular Ca2+, a reduction of ATP pools in the cells or a direct effect on calmodulin. Concentrations of TMB-8 that inhibited PD induction had little effect on the cyclic GMP response. Therefore, this compound did not inhibit PD induction indirectly by blocking cyclic GMP synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

3',5'-Cyclic-AMP Phosphodiesterases↗

Effect of anti-lymphocyte induction therapy on renal allograft survival: a meta-analysis.

Induction immunosuppression with antilymphocyte antibodies has not been shown to improve cadaveric kidney allograft survival in randomized, controlled trials despite widespread use. This meta-analysis of randomized, controlled trials assessed the effectiveness of induction therapy in prolonging allograft survival. Studies of induction therapy were identified in Medline (1986 through 1996), using the terms "monoclonal antibodies" or "antilymphocyte serum," and "kidney transplantation," "human," and "clinical trial." Bibliographies, pharmaceutical manufacturers, the United Network for Organ Sharing, National Institutes of Health, and study authors were also consulted. Seven of 247 identified studies met the following inclusion criteria: (1) an adult study population; (2) assessment of antilymphocyte antibodies in the immediate posttransplant period; (3) a control arm of cyclosporine, azathioprine, and prednisone in the immediate posttransplant period; and (4) presentation of survival data. Two readers independently extracted protocol and survival data from each study. Summary odds ratios (fixed and random effects) and a rate ratio from proportional hazards regression at 2 yr were estimated to examine the effect of induction therapy on allograft survival. The summary odds ratios were both 0.66 (confidence interval [CI], 0.45 to 0.96; P = 0.03), and the rate ratio was 0.69 (CI, 0.49 to 0.97; P = 0.03), indicating a beneficial effect of induction therapy on allograft survival. Allograft survival was 85.6% (CI, 82.1 to 89.1%) in the induction therapy group and 79.6% (CI, 75.6 to 83.6%) in the conventional therapy group. These results were stable in a sensitivity analysis based on study quality. Allograft survival was prolonged with induction therapy compared with conventional immunosuppression. These data indicate a potential role for the routine use of induction therapy in renal transplantation to optimize the survival of cadaveric allografts.

Adult↗

Induction of heme oxygenase-1 and heat shock protein 70 in rat hepatocytes: the role of calcium signaling.

Stress response genes including heat shock proteins are induced under a variety of conditions to confer cellular protection. This study investigated the role of calcium signaling in the induction of two stress response genes, heme oxygenase-1/hsp32 and hsp70, in isolated rat hepatocytes. Both genes were induced by cellular glutathione depletion. This induction could be inhibited by BAPTA-AM. Culturing in a calcium-free medium prevented the induction of hsp70 gene expression after glutathione depletion without affecting heme oxygenase-1 gene expression. Thapsigargin increased the gene expression of heme oxygenase-1 but not that of hsp70. Thapsigargin-induced heme oxygenase-1 induction was completely inhibited by BAPTA-AM. Incubation with the Ca(2+)-ionophore A23187 augmented heme oxygenase-1 (two-fold) and hsp70 (5.2-fold) mRNA levels. Our data suggests a significant role of Ca(2+)-dependent pathways in the induction of the two stress genes. An increase in the cytoplasmic Ca(2+) activity seems to play a key role in the cascade of signaling leading to the induction of the two genes. However, the source of Ca(2+) that fluxes into the cytoplasm seems to be different. Our data provides evidence for a compartmentalization of calcium fluxes, i.e. the Ca(2+) flux from intracellular stores (e.g. the endoplasmic reticulum) plays a major role in the induction of heme oxygenase-1. By contrast, Ca(2+) flux from the extracellular medium seems to be a mechanism initiating the cellular signaling cascade leading to hsp70 gene induction.

Animals↗

Induction of ornithine decarboxylase and augmentation of tyrosine aminotransferase activity by N-hydroxy-2-acetylaminofluorene and 2-acetylaminofluorene in rat liver. Influence of sex, retinylacetate, indomethacin, and pentachlorophenol.

IP injection in rats of 2-acetylaminofluorene (AAF) or N-hydroxy-2-acetylaminofluorene (N-OH-AAF) resulted in a transient increase of hepatic ornithine decarboxylase (ODC) and tyrosine aminotransferase (TAT) activity. Maximal activity of ODC was observed 4 hr and of TAT 3 hr after administration of either AAF or N-OH-AAF. A lag-time of 2 hr preceded the increase of ODC and TAT activity. N-OH-AAF dependent ODC induction displayed an almost linear dose-response in the dose range up to 94.1 mumol/kg bw (body weight) when the ODC activity was measured at its maximum 4 hr after administration. Elevation of the dose N-OH-AAF to 126 mol/kg bw resulted in a lower ODC induction. Administration of doses AAF to 31.4 mumol did not change ODC activity. At doses up to 126 mumol/kg bw ODC induction increased linear. TAT induction increased linear in the dose range 15.7-94.1 mumol N-OH-AAF and 31.4-94.1 mumol AAF/kg. Lowering the dose of AAF did not result in a lower ODC or TAT activity. Judged by the effects of actinomycin D or cycloheximide administered 1 hr prior to AAF or N-OH-AAF, the in vivo induction of rat liver ODC activity by AAF and N-OH-AAF appeared to be under transcriptional control, whereas augmentation of TAT activity under influence of AAF or N-OH-AAF appeared the result of (post) translational events. Induction of ODC by AAF or N-OH-AAF was not significantly changed by indomethacin, was slightly increased by pentachlorophenol (PCP) and was synergistically enhanced by retinylacetate (RA). The increase of TAT activity was stimulated by PCP and RA. The effect of PCP indicates that N-sulfonoxy-2-acetylaminofluorene is most probably not involved in the induction of ODC. AAF appeared more effective hepatic ODC inducer in females than males and moreover more effective than N-OH-AAF in females. N-OH-AAF had stronger ODC inducing capacity in males than females. Similar observations were made with respect to TAT activity. When induction of ODC is indicative for a tumor promoting property then the data presented here suggest that tumor promotion of the complete carcinogens AAF and N-OH-AAF is not mediated by N-O-sulfation; this might be due to other metabolic conversions.

2-Acetylaminofluorene↗

Does ovulation induction affect the pregnancy rate after laparoscopic treatment of endometriosis?

OBJECTIVE: To determine the effectiveness of ovulation induction after laparoscopic treatment of endometriosis in an infertile population. DESIGN: An observational prospective study in which infertility cases were treated with laparoscopic surgery was followed up (mean 11 months), either by treatment (ovulation induction) or no further treatment (expectant management) and the outcomes recorded. In both groups pregnancies were compared by Cox's regression survival model. SETTING: Gazi University Hospital, Department of Obstetric and Gynecology, Ankara, Turkey. PATIENTS: Infertile women with different stages of endometriosis who were treated by laparoscopic surgery, with a mean duration of infertility of 80.7 (+/-50 [SD]) months. INTERVENTIONS: Patients were treated by cauterization of the foci, adhesiolysis, endometrioma stripping, and distal tubal reconstruction according to their lesions. Postoperatively, patients had either ovulation induction (clomiphene, hMG) therapy or no further treatment. MAIN OUTCOME MEASURE: Cumulative pregnancy rate of infertile women after laparoscopic treatment of endometriosis with or without ovulation induction. RESULTS: A total of 36 out of 128 patients became pregnant after laparoscopy, with a 34% cumulative pregnancy rate. In the ovulation induction group, relative risk (chance) of pregnancy was 1.42 (1.02-2.05, 95 % CI) when the duration of infertility was less than 5 years. In this lower risk group, the overall cumulative pregnancy rate was 46%--56% and 27% for the ovulation induction and expectant management groups, respectively. In the expectant management group, per cycle fecundity was 0.021, whereas it was 0.066 and 0.174 (p = 0.001) in the clomiphene citrate- and hMG-treated patients, respectively. Expectant management significantly increased the likelihood of pregnancy compared to ovulation induction in previous pregnancy, stage 1 or 2 endometriosis, and no male infertility groups (p = 0.04-0.009). CONCLUSION: After laparoscopic treatment of endometriosis, ovulation induction has a positive effect only if done with hMG and the duration of infertility was less than 5 years (P<.05).

Adult↗

Dose and inducer-dependent induction of cytochrome P450 1A in endothelia of the eel, including in the swimbladder rete mirabile, a model microvascular structure.

Endothelium is a common site of cytochrome P450 1A (CYP1A) induction in vertebrates, and endothelial CYP1A could affect the distribution and toxicity of CYP1A substrates. We investigated CYP1A induction in organs rich in endothelium, gill, heart, and a microvascular model, the swimbladder rete mirabile, in the eel. Benzo[a]pyrene (BP) and 3, 3',4,4'-tetrachlorobiphenyl (TCB), radiolabeled and injected intraperitoneally, showed similar distribution in eels, with dose-dependent increases in concentration in heart and rete mirabile. BP [given at 0.1, 1, and 10 mg/kg (0.4, 4, and 40 micromol/kg)], TCB [given at 0.1, 1, and 10 mg/kg (0.3, 3, 30, and 60 micromol/kg)], and beta-naphthoflavone (BNF) [given at 0.1, 1, 5, 10, and 100 mg/kg (0.4, 4, 20, 40, and 400 micromol/kg)] induced microsomal CYP1A and ethoxyresorufin O-deethylase in heart and rete mirabile. Immunohistochemical analysis confirmed that induction of CYP1A in heart and rete mirabile occurs in the endothelium. Increasing doses of each compound caused increasing penetration of induction into the vascular bed of the rete, but with BNF and BP induction penetrated further than with TCB. At high doses of BNF there also was induction in epithelial cells adjacent to endothelium in gill and kidney. CYP1A also was induced in heart and rete mirabile of eels from sites heavily contaminated by aryl hydrocarbon receptor (AHR) agonists. The penetration of CYP1A induction into capillaries of the rete mirabile reflects the penetration of the inducer itself, consistent with the idea that endothelial CYP1A can indicate the local distribution of AHR agonists. The microvascular rete mirabile in the eel provides a model system to explore further a hypothesis that endothelial CYP1A participates in removal of some AHR agonists from the circulation and to examine the consequences of CYP1A induction to the vascular system.

Animals↗

Intensified double induction therapy with high dose mitoxantrone, etoposide, m-amsacrine and high dose ara-C for elderly acute myeloid leukemia patients aged 61-65 years.

BACKGROUND AND OBJECTIVES: Treatment outcome in elderly patients with acute myeloid leukemia (AML) is still disappointing. However, some trials showed that increasing the dosage of anthracyclines within induction therapy improved treatment outcome substantially. We, therefore, tried to escalate induction therapy further in a group of young elderly AML patients. DESIGN AND METHODS: In a multicenter trial 33 patients aged 61-65 years with de novo or secondary AML were treated with double induction therapy including high dose mitoxantrone, etoposide and ara-C (MAV) in the first course and m-amsacrine together with high dose ara-C (MAMAC) in the second course. Treatment results were compared to those in 39 AML patients older than 65 years receiving conventional double induction therapy including daunorubicin and ara-C (DA I and DA II) within the same time period. RESULTS: Compared to results achieved with conventional induction therapy, intensified double induction therapy did not significantly improve CR rates, overall or disease-free survival. Hematologic toxicity was not different between the two groups, but non-hematologic toxicity was significantly higher with MAV/MAMAC. This was mainly due to gastro-intestinal or liver toxicity. The rate of early mortality (death within the first 12 weeks) was 42% in the group receiving intensified therapy and 18% in that given conventional induction therapy (p=0.04). INTERPRETATION AND CONCLUSION: Intensification of double induction therapy using high dose mitoxantrone and high dose ara-C in AML patients aged 61-65 years did not lead to improved treatment outcome and conferred an unacceptable early death rate due to high non-hematologic toxicity. Risk-adapted or alternative treatment strategies are needed to improve treatment outcome in these young elderly AML patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗