Abstract P3-06-33: Effect of trastuzumab-based therapy on serum activin A levels in metastatic breast cancer

Background: Only half of HER2-positive metastatic breast cancer patients will respond to first-line trastuzumab-containing therapy, but of these, most will progress within a year. Trastuzumab resistance remains a continuing clinical problem, and better biomarkers and therapies are needed. Activin A is a TGF-beta superfamily member that regulates cell proliferation, apoptosis, differentiation, and immune response. We have previously reported that higher pretreatment serum activin A level predicted reduced progression-free survival (PFS) and overall survival (OS) to first-line trastuzumab, independent of age, line of therapy, CA 15–3, and hormone receptor status (ASCO Ab ID 607, 2012).

Methods: Serum activin A was measured using ELISA (R&D Systems, Minneapolis, MN) in 60 metastatic breast cancer patients before and 1 month after starting first-line trastuzumab-containing therapy. PFS and OS were analyzed using the Kaplan-Meier method and Cox modeling with both continuous and dichotomous (median) serum activin A analyses.

Results: Pretreatment serum activin A levels had a median of 629 pg/mL and an inter-quartile range of 406 to 1791 pg/mL. There was no significant change in activin A levels between pretreatment and one month after starting trastuzumab therapy. Median activin A level at one month was 655 pg/mL, with an inter-quartile range of 405 to 1517 pg/mL. 83% of patients who had low pretreatment activin A levels (below median) had low activin levels at one month, and 83% who had high activin levels (above median) at baseline had high activin A levels at one month. Patients who had high activin A levels at baseline and one month had the worst outcome for both PFS (HR 3.9; median 134 days vs.776 days; p < 0.0001) and OS (HR 6.7; p < 0.0001) when compared to patients with low activin A levels which remained low at one month.

Conclusions: Higher pretreatment and 1 month post-treatment serum activin A predicted for reduced PFS and overall survival in metastatic breast cancer patients treated with first-line trastuzumab-containing therapy. Trastuzumab-based therapy did not have a significant effect on activin A levels at one month. Patients with persistently high activin A levels had significantly worsened outcomes compared to those with low activin A levels. Serum activin A deserves further study to select patients most likely to respond to activin A-targeted therapy.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-33.

Abstract P5-20-03: A phase 2, double-blind, randomized, placebo-controlled, dose-finding study of sotatercept for the treatment of patients with chemotherapy-induced anemia and metastatic breast cancer

Background: Sotatercept is a recombinant activin receptor IIA (ActRIIA) ligand trap and is comprised of the extracellular domain of ActRIIA linked to the Fc domain of human IgG1 (ActRIIA-IgG1). Results of preclinical and early clinical studies provide evidence that sotatercept increases the concentration of hemoglobin (Hb) in blood and may constitute a novel treatment for chemotherapy-induced anemia (CIA), a condition that results in significant morbidity.

Methods: This study evaluated the safety of, and hematopoietic response to, sotatercept in patients with CIA and metastatic breast cancer (MBC). Response was defined as increase in Hb ≥1 g/dL for ≥28 consecutive days during treatment or ≤2 months following the last dose, in the absence of red blood cell (RBC) transfusion or treatment with an erythropoiesis stimulating agent (ESA). If RBC transfusion or treatment with an ESA was required, no Hb measurements within 28 days of the RBC transfusion or administration of ESA were used to determine the Hb response. Subjects were randomized to subcutaneous injection of sotatercept (0.1, 0.3, or 0.5 mg/kg) or placebo and were treated on day 1 of each of four 28-day cycles.

Results: Thirty (30) subjects were enrolled and treated (5 placebo, 25 sotatercept). Increases in mean Hb in the 0.3 and 0.5 mg/kg groups were greater than in 0.1 mg/kg and placebo groups. Increases peaked approximately 15 days following treatment and declined over the remaining interval between treatments. Among 23 subjects with confirmed CIA and administered ≥1 dose and followed for ≥57 days (per-protocol analysis), 5/18 (28%) administered sotatercept responded (0/5 [0%] at 0.1 mg/kg; 3/9 [33%] at 0.3 mg/kg; 2/4 [50%] at 0.5 mg/kg) vs 1/5 [20%] administered placebo. Among 13 nonresponders administered sotatercept, 5 (39%) experienced ≥1 dose interruption/reduction, as per protocol, due to elevated Hb. The incidence of adverse events (AEs) was consistent with that reported in patients with MBC. No dose-limiting or dose-related toxicity was observed.

Conclusions: Sotatercept demonstrated dose-dependent hematopoietic activity in subjects with CIA and MBC. The safety findings were generally consistent with the known safety profile of sotatercept. These data suggest that a greater dose of sotatercept or a dose interval <28 days might result in a more sustained, and greater rate of, hematopoietic response.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-20-03.

Clinical studies with tumour necrosis factor

The mechanism of tumour necrosis factor (TNF) cytotoxicity remains unknown. The in vivo antitumour effects of TNF may be related to direct cytotoxicity, immunomodulatory effects or endothelial effects on tumour vasculature. Phase I and early Phase II clinical trials of human recombinant TNF are under way in Japan, the USA, the UK and Germany. The maximum Phase II dose for TNF has not been established. The clinical toxicity of TNF is generally similar to that of other biological agents. Systemic toxicity, including fever, chills, anorexia and nausea, has been seen in most patients treated with TNF and has not been clearly related to dose. Other toxicities have included liver function abnormalities, hypotension, transient neurological changes and haematological abnormalities. Few clinical responses have been reported but organized Phase II testing remains to be completed. Combination trials with interferons have recently been initiated. Phase II efficacy studies of TNF as a single agent and in combination are needed for an assessment of the value of this agent in cancer therapy.

Two phase I studies of low dose recombinant human IL-12 with Melan-A and influenza peptides in subjects with advanced malignant melanoma

Preclinical studies have shown that low dose IL-12 can potentiate cytotoxic lymphocyte responses. Since previous trials have demonstrated significant toxicity from high dose recombinant human IL-12 (rhIL-12), we sought to determine an optimal biological dose for rhIL-12 at lower doses when combined with peptide antigens. Two studies were undertaken. The rhIL-12 was administered at doses of 0 (placebo), 10, 30 and 100 ng/kg, subcutaneously in one study and intravenously in the other. Apart from IL-12 dosing, the studies were identical. Subjects had evaluable stage III or IV melanoma which expressed Melan-A by RT-PCR or immunohistochemistry. Melan-A (26-35) (EAAGIGILTV) and influenza matrix (58-66) (GILGFVFTL) peptides were administered intradermally on weeks 1, 2, 3, 4 and 9. Twenty-eight subjects were enrolled, of whom 24 were evaluable for clinical and immunological responses. Therapy was well tolerated, the main adverse event being influenza-like symptoms. Immunological monitoring included the evaluation of cutaneous reactions and assays for antigen-specific T-cells. Clinical responses included a complete response in a subject with small volume subcutaneous disease, a partial response in a subject with hepatic metastases, and mixed responses in pulmonary, pleural and nodal disease. Biopsies of accessible tumors showed infiltration with CD4+ and CD8+ lymphocytes capable of lysing Melan-A peptide-pulsed targets in vitro. No clear dose-dependent effect of rhIL-12 could be determined. The rhIL-12 given either s.c. or i.v. was well tolerated at doses of 10-100 ng/kg. Clinical and immunological activity has been observed in this study where peptides were administered either with or without low dose rhIL-12.

Chemical orientation of brown bullheads, Ameiurus nebulosus, under different flow conditions

The spatiotemporal information in chemical signals provides critical information for organisms during chemical orientation. Information in chemical signals is influenced by the hydrodynamic conditions of the environment. Hydrodynamically distinct environments will contain different types of information, which will influence how organisms orient. This study was designed to examine how the orientation behavior of the brown bullhead (Ameiurus nebulosus) is influenced by flow regime. The experiment was conducted in a flume under two different flow conditions. Treatments consisted of control (no odor) and plain gelatin (odor). Percent success, swimming speed, turning angle, heading angle, heading angle upstream, and net-to-gross ratio were analyzed. Brown bullheads were 100% successful in finding the odor source under no flow and 57% successful in flow. Bullheads swam differently in the no-flow condition when compared to the flow condition. Since, these fish did not orient the same under different flow conditions, it appears that hydrodynamics plays a role in shaping their behavior.

The role for interleukin-12 therapy of cutaneous T cell lymphoma

Recent phase I and phase II trials using recombinant human interleukin-12 (rhIL-12) for cutaneous T cell lymphoma (CTCL) have been completed. Observations on 32 evaluable patients revealed an overall response rate approaching 50 percent. Biopsy of regressing lesions revealed an increase in numbers of CD8+ and/or TIA-1+ T cells. These results suggest that rhIL-12 may induce lesion regression by augmenting antitumor cytotoxic T cell responses. Future trials will be focused on strategies for further immune enhancement by the concomitant use of additional immune augmenting cytokines with rhIL-12.

Efficacy and safety of gemtuzumab ozogamicin in patients with CD33-positive acute myeloid leukemia in first relapse

PURPOSE

Three open-label, multicenter trials were conducted to evaluate the efficacy and safety of single-agent Mylotarg (gemtuzumab ozogamicin; CMA-676; Wyeth Laboratories, Philadelphia, PA), an antibody-targeted chemotherapy agent, in patients with CD33-positive acute myeloid leukemia (AML) in untreated first relapse.

PATIENTS AND METHODS

The study population comprised 142 patients with AML in first relapse with no history of an antecedent hematologic disorder and a median age of 61 years. All patients received Mylotarg as a 2-hour intravenous infusion, at a dose of 9 mg/m(2), at 2-week intervals for two doses. Patients were evaluated for remission, survival, and treatment-emergent adverse events.

RESULTS

Thirty percent of patients treated with Mylotarg obtained remission as characterized by 5% or less blasts in the marrow, recovery of neutrophils to at least 1,500/microL, and RBC and platelet transfusion independence. Although patients treated with Mylotarg had relatively high incidences of myelosuppression, grade 3 or 4 hyperbilirubinemia (23%), and elevated hepatic transaminase levels (17%), the incidences of grade 3 or 4 mucositis (4%) and infections (28%) were relatively low. There was a low incidence of severe nausea and vomiting (11%) and no treatment-related cardiotoxicity, cerebellar toxicity, or alopecia. Many patients received Mylotarg on an outpatient basis (38% and 41% of patients for the first and second doses, respectively). Among the 142 patients, the median total duration of hospitalization was 24 days; 16% of patients required 7 days of hospitalization or less.

CONCLUSION

Administration of the antibody-targeted chemotherapy agent Mylotarg to patients with CD33-positive AML in first relapse induces complete remissions with what appears to be a favorable safety profile.

Bilateral eventration of the diaphragm with perforated gastric volvulus in an adolescent

Bilateral congenital eventration of the diaphragm almost uniformly presents in infancy with respiratory compromise and is associated with a high mortality rate. Delayed presentation of diaphragmatic eventration in older children and adults may be associated with acute gastric volvulus. Thus, any patient with abdominal pain, vomiting, or nonspecific gastrointestinal symptoms in association with abnormal diaphragmatic findings on chest x-ray should undergo further diagnostic workup with upper gastrointestinal series or computed tomography (CT) scan. Treatment of gastric volvulus requires immediate surgical repair to prevent subsequent necrosis and perforation. The authors describe a case report of bilateral congenital diaphragmatic eventration complicated by a perforated gastric volvulus in a 13-year-old boy. Emergent reduction of the volvulus, closure of the perforated stomach, plication of the diaphragm, and placement of gastrostomy was performed successfully.

Interleukin-12 therapy of cutaneous T-cell lymphoma induces lesion regression and cytotoxic T-cell responses

Progression of cutaneous T-cell lymphoma (CTCL) is associated with profound defects in cell-mediated immunity and depressed production of cytokines, which support cell-mediated immunity. Because we have observed marked defects in interleukin-12 (IL-12) production in CTCL and because IL-12 is critical for antitumor cytotoxic T-cell responses, we initiated a phase I dose escalation trial with recombinant human IL-12 (rhIL-12) where patients received either 50, 100, or 300 ng/kg rhIL-12 twice weekly subcutaneously or intralesionally for up to 24 weeks. Ten patients were entered: 5 with extensive plaque, 3 with Sezary syndrome, and 2 with extensive tumors with large cell transformation. One patient with Sezary syndrome dropped out after 1 week for personal reasons. Subcutaneous dosing resulted in complete responses (CR) in 2 of 5 plaque and partial responses (PR) in 2 of 5 plaque, and 1 of 2 Sezary syndrome (overall response rate CR+PR 5 of 9, 56%). A minor response also occurred in 1 of 5 plaque patients. Intralesional dosing resulted in individual tumor regression in 2 of 2 patients. Biopsy of regressing lesions showed a significant decrease in the density of the infiltrate in all cases and complete resolution of the infiltrate among those with clinical lesion resolution. An increase in numbers of CD8-positive and/or TIA-1-positive T cells were observed on immunohistochemical analysis of skin biopsy specimens obtained from regressing skin lesions. Adverse effects of rhIL-12 on this regimen were minor and limited and included low-grade fever and headache. One patient discontinued rhIL-12 at week 6 because of depression. These results suggest that rhIL-12 may augment antitumor cytotoxic T-cell responses and may represent a potent and well-tolerated therapeutic agent for CTCL.

Immunological effects of interleukin 12 administered by bolus intravenous injection to patients with cancer

The immunological effects of recombinant human interleukin 12 (rhIL-12) administration were examined during the conduct of a Phase I clinical trial. Forty patients with advanced cancer received bolus i.v. injections of rhIL-12 in doses ranging between 3 and 1000 ng/kg. Dose-dependent increases in serum IFN-gamma levels were seen during rhIL-12 therapy. Significant lymphopenia was observed 24 h after single i.v. injections of rhIL-12 at each dose level. The degree of lymphopenia was dose dependent, and a plateau effect was seen with rhIL-12 doses of 100 ng/kg and higher. Lymphocyte counts reached nadir levels at approximately 10 h after rhIL-12 injection and returned to baseline within 14 days postinjection. Rebound lymphocytosis, as seen after interleukin 2 therapy, was not observed after recovery from rhIL-12-induced lymphopenia. rhIL-12-induced lymphopenia involved all major lymphocyte subsets, although natural killer (NK) cell numbers were the most profoundly affected, and CD4 T-cell numbers were the least affected. CD2, LFA-1, and CD56 were transiently up-regulated on the surface of NK cells exposed to rhIL-12 in vivo. Peripheral blood mononuclear cells obtained from cancer patients before rhIL-12 therapy exhibited defective NK cell cytotoxicity and T-cell-proliferative responses. Peripheral blood mononuclear cells obtained after lymphocyte recovery following the administration of a single 500 ng/kg dose of rhIL-12 displayed augmented NK cell cytolytic activity in four of four patients tested and enhanced T-cell proliferation in three of four patients tested. These studies confirm that doses of rhIL-12 resulting in significant immunological activity can be administered with acceptable toxicity to cancer patients. Furthermore, rhIL-12 therapy can reverse defects in NK cell and T-cell function that are associated with advanced cancer in humans.

Effects of single-dose interleukin-12 exposure on interleukin-12-associated toxicity and interferon-gamma production

Interleukin-12 (IL-12) is a key regulator of cell-mediated immunity that has therapeutic potential in cancer and infectious disease. In a previous Phase 1 dose escalation study of a single test dose of recombinant human IL-12 (rhIL-12) followed 14 days later by cycles of five consecutive daily intravenous injections every 3 weeks, we showed that a dose level up to 500 ng/kg could be administered with acceptable levels of safety. Based on these results, a Phase 2 study was conducted. In the Phase 2 study, however, administration of rhIL-12 at this same dose level resulted in severe toxicities with some patients unable to tolerate more than two successive doses. Of the 17 patients receiving rhIL-12 in the Phase 2 study, 12 patients were hospitalized and two patients died. A thorough scientific investigation to determine the cause of this unexpected toxicity failed to identify any difference in the drug products used or the patient populations enrolled in the Phase 1 and Phase 2 studies that could have accounted for the profound difference in toxicity. The focus of the investigation therefore shifted to the schedule of rhIL-12 administration. We determined that a single injection of rhIL-12 2 weeks before consecutive dosing included in the Phase 1 study, but not in the schedule of administration in the Phase 2 study, has a profound abrogating effect on IL-12-induced interferon-gamma (IFN-gamma) production and toxicity. This observation of schedule-dependent toxicity of IL-12 has been verified in mice, as well as nonhuman primates. In this regard, a single injection of IL-12 before consecutive daily dosing protected mice and cynomolgus monkeys from acute toxicity including mortality and was associated with an attenuated IFN-gamma response. Because of this unique biologic response, careful attention to the schedule of administration is required to assure safe and effective clinical development of this highly promising cytokine.

Intraventricular hemorrhage and fetal heart rate in very low birth weight infants

OBJECTIVE

This study was designed to investigate the relationship between fetal heart rate patterns before delivery and periventricular-intraventricular hemorrhage in the very low birth weight infant.

STUDY DESIGN

The last 30 minutes of electronic fetal heart rate data preceding delivery were analyzed for 84 singleton infants weighing between 700 and 1500 gm. All these infants received serial cranial ultrasonographic examinations commencing within 24 to 48 hours of birth.

RESULTS

Thirty-three fetuses had normal heart rate patterns, and 51 had fetal heart rate abnormalities. Periventricular-intraventricular hemorrhage was not associated with fetal heart rate abnormalities. Univariate and multivariate regression analysis demonstrated that only gestational age < 28 weeks was a significant contributing factor to periventricular-intraventricular hemorrhage (odds ratio 2.2, 95% confidence interval [CI], 1.0 to 4.8).

CONCLUSION

Fetal heart rate patterns immediately preceding delivery are not predictive of periventricular-intraventricular hemorrhage in the very low birth weight infant.

Quality control for DNA contamination in laboratories using PCR-based class II HLA typing methods

Quality control (QC) in laboratories performing molecular histocompatibility class II typing often includes a polymerase chain reaction (PCR) approach for monitoring DNA contamination. An oligonucleotide primer set was designed, (RBQBf/RBQBr), which is specific for nonpolymorphic regions of the DR-B, DQ-B, and DP-B consensus sequences with an expected PCR product size of 81 bp. RBQBf/RBQBr detected genomic DNA from reference cell lines LWAGS and BM21 (50 to 100 picograms) as well as DR-B, DP-B, and DQ-B amplicon (1 copy). Additionally, RBQBf/RBQBr detected SSP products from routine DR-B and DQ-B typings. Validation studies employing controlled DNA contamination of laboratory surfaces revealed that increasing amounts of wipe test samples (5% to 20% v/v) were inhibitory to the wipe test PCR, whereas lower amounts (1% to 2%), or alternatively, a diluted wipe test sample, increased the sensitivity of the test and optimized the results. Collectively, this study describes a primer set, RBQBf/RBQBr, which detects both genomic DNA and DR-B, DQ-B, or DP-B amplicon and furthermore illustrates the necessity of routine testing for potential inhibitory factors that may be introduced into the wipe test PCR.

Phase I evaluation of intravenous recombinant human interleukin 12 in patients with advanced malignancies

A Phase I dose escalation trial of i.v. administered recombinant human interleukin 12 (rhIL-12) was performed to determine its toxicity, maximum tolerated dose (MTD), pharmacokinetics, and biological and potential antineoplastic effects. Cohorts of four to six patients with advanced cancer, Karnofsky performance >/=70%, and normal organ function received escalating doses (3-1000 ng/kg/day) of rhIL-12 (Genetics Institute, Inc.) by bolus i.v. injection once as an inpatient and then, after a 2-week rest period, once daily for five days every 3 weeks as an outpatient. Therapy was withheld for grade 3 toxicity (grade 4 hyperbilirubinemia or neutropenia), and dose escalation was halted if three of six patients experienced a dose-limiting toxicity (DLT). After establishment of the MTD, eight more patients were enrolled to further assess the safety, pharmacokinetics, and immunobiology of this dose. Forty patients were enrolled, including 20 with renal cancer, 12 with melanoma, and 5 with colon cancer; 25 patients had received prior systemic therapy. Common toxicities included fever/chills, fatigue, nausea, vomiting, and headache. Fever was first observed at the 3 ng/kg dose level, typically occurred 8-12 h after rhIL-12 administration, and was incompletely suppressed with nonsteroidal anti-inflammatory drugs. Routine laboratory changes included anemia, neutropenia, lymphopenia, hyperglycemia, thrombocytopenia, and hypoalbuminemia. DLTs included oral stomatitis and liver function test abnormalities, predominantly elevated transaminases, which occurred in three of four patients at the 1000 ng/kg dose level. The 500 ng/kg dose level was determined to be the MTD. This dose, administered by this schedule, was associated with asymptomatic hepatic function test abnormalities in three patients and an onstudy death due to Clostridia perfringens septicemia but was otherwise well tolerated by the 14 patients treated in the dose escalation and safety phases. The T1/2 elimination of rhIL-12 was calculated to be 5.3-9.6 h. Biological effects included dose-dependent increases in circulating IFN-gamma, which exhibited attenuation with subsequent cycles. Serum neopterin rose in a reproducible fashion regardless of dose or cycle. Tumor necrosis factor alpha was not detected by ELISA. One of 40 patients developed a low titer antibody to rhIL-12. Lymphopenia was observed at all dose levels, with recovery occurring within several days of completing treatment without rebound lymphocytosis. There was one partial response (renal cell cancer) and one transient complete response (melanoma), both in previously untreated patients. Four additional patients received all proposed treatment without disease progression. rhIL-12 administered according to this schedule is biologically and clinically active at doses tolerable by most patients in an outpatient setting. Nonetheless, additional Phase I studies examining different schedules and the mechanisms of the specific DLTs are indicated before proceeding to Phase II testing.

Phase I study of continuous-infusion recombinant macrophage colony-stimulating factor in patients with metastatic melanoma

Macrophage colony-stimulating factor (M-CSF) is a lineage-specific, homodimeric growth factor that supports the proliferation and maturation of bone marrow progenitors and the survival and function of mononuclear/macrophage cells. In vitro studies have demonstrated antitumor activity of macrophage colony-stimulating factor-treated monocytes against melanoma target cells. A Phase I study was conducted by administering the glycosylated form of the protein to patients with metastatic melanoma as two 7-day continuous i.v. infusions separated by a 2-week rest. Cohorts of three patients per dose level received escalating doses of 10-160 microgram/kg/day. Safety, clinical, and biological effects were evaluated. The infusions were well tolerated with occasional maximum grade 2 nonhematological toxicity. Rapidly reversible thrombocytopenia was the major hematological adverse effect. Its etiology may in part be explained by proliferation and activation of monocyte/macrophage cells in bone marrow samples. Evidence for a biological effect on tumors was suggested by the delayed, complete disappearance of multiple lesions in one patient and a decrease in the size of one marker lesion in a second patient with a mixed response. Fasting serum cholesterol levels decreased during the infusions and may represent an additional therapeutic application for this growth factor.

Randomized investigation of antimicrobials for the prevention of preterm birth

OBJECTIVE

Occult amniotic fluid infection has emerged as a possible cause of many heretofore unexplained preterm births. We sought to determine whether antimicrobial therapy is effective in preventing preterm delivery.

STUDY DESIGN

A double-blind, placebo-controlled, randomized trial was conducted to study the efficacy of ampicillin-sulbactam and amoxicillin-clavulanic acid in women hospitalized for preterm labor between 24 and 34 weeks' gestation. During this investigation no tocolytics or steroids were used.

RESULTS

Thirty-nine women with preterm labor received antimicrobial therapy and 39 received placebos. The mean gestational ages at study entry were 29.8 +/- 0.4 weeks (SEM) and 30.6 +/- 0.3 weeks in the antimicrobial and placebo groups, respectively (not significant). Similarly, the mean gestational ages at delivery were 34.2 +/- 0.7 and 34.1 +/- 0.6 weeks, respectively (not significant). Other index values of pregnancy outcome, for example, birth weight, neonatal morbidity, and prenatal death, were not significantly improved by antimicrobial therapy given to the mother in preterm labor.

CONCLUSION

We find that antimicrobial therapy given to women in preterm labor is ineffective in the prevention of preterm birth.

Association between workers' compensation and outcome following multidisciplinary treatment for chronic pain: roles of mediators and moderators

OBJECTIVE

To determine whether the tendency for chronic pain patients who receive Workers' Compensation to show a poorer response than non-compensated patients to pain treatment can be accounted for by mediating factors; to assess whether moderating factors can distinguish subgroups of Workers' Compensation recipients who react very poorly to treatment from compensated patients who respond well.

DESIGN

Outcome study based on archives.

SETTING

Multidisciplinary pain treatment center.

PATIENTS

Of 214 patients, 158 had complete data.

OUTCOME MEASURE

Blind ratings of narrative discharge summaries written by the Pain Treatment Center staff.

RESULTS

A significant negative relationship between receiving Workers' Compensation and outcome was mediated by a pessimistic belief in the ability to return to former occupation. Moderator effects showed that Workers' Compensation recipients with high initial pain and a history of pain-related surgery fared worse than any other group. Moreover, Workers' Compensation recipients not characterized by high pain and a history of surgery responded as well as noncompensated patients.

CONCLUSIONS

The inadequate response to pain programs shown by Workers' Compensation recipients may be partly understood in terms of well-defined mediating factors, which may admit to amelioration via clinical intervention. Moreover, Workers' Compensation patients should not be considered high risks for failure by sole virtue of their compensation status. Multifactor assessment methods may be needed to identify that portion of compensation recipients who are actually at appreciable risk for treatment failure so that appropriate adjustments in treatment regimen may be made.

Maternal youth and pregnancy outcomes: middle school versus high school age groups compared with women beyond the teen years

OBJECTIVE

We sought to measure and compare pregnancy complications in middle school versus high school versus older maternal age groups.

STUDY DESIGN

From January 1988 through December 31, 1991, maternal and infant data from 16,512 consecutive nulliparous women were collected and electronically stored. These women were divided into three study groups: middle school (11 to 15 years old), high school (16 to 19 years old), and women 20 to 22 years old at delivery. Statistical analysis included logistic regression to control for potentially confounding demographic variables.

RESULTS

Middle school-aged mothers were disproportionately black (50% vs 36% Hispanic vs 14% white), and very low birth weight (4% vs. 2%, p = 0.003) was increased in these youthful mothers. First births to high school-aged mothers were not found to be compromised compared with those of women 20 to 22 years old, and, indeed, cesarean birth was less frequent in these women compared with those > or = 20 years old.

CONCLUSIONS

We conclude that the health hazard associated with school-age pregnancy is predominantly prematurity and is increased only in middle school-aged mothers. High school-aged mothers do not experience excess medical complications of pregnancy compared with older women. We suggest that middle school pregnancy, particularly for inner-city teenagers, should be a special focus for pregnancy prevention and intervention.

Meconium: a 1990s perspective on an old obstetric hazard

OBJECTIVE

To quantify the current perinatal consequences associated with intrapartum detection of meconium in the amniotic fluid (AF).

METHODS

We compared retrospectively the outcomes in 8136 term singleton cephalic pregnancies with meconium and 34,573 similar pregnancies with clear AF.

RESULTS

Virtually all measures of adverse fetal-neonatal outcomes were significantly increased with meconium. For example, perinatal mortality increased from 0.3 per 1000 births with clear AF to 1.5 deaths per 1000 with meconium (P < .001). Most of these deaths resulted from meconium aspiration. Other unwanted outcomes also increased; eg, severe fetal acidemia at birth (umbilical artery blood pH 7.00 or less) increased from three per 1000 to seven per 1000 when meconium was diagnosed (P < .001). Delivery by cesarean also increased with meconium, from 7 to 14% (P < .001).

CONCLUSION

Meconium in the AF is an obstetric hazard with small but significantly increased risks of adverse fetal-neonatal outcomes.

High-dose oxytocin: 20- versus 40-minute dosage interval

OBJECTIVE

To determine whether an increase in the oxytocin dosing interval would decrease the incidence of uterine hyperstimulation.

METHODS

This study included 1801 consecutive pregnancies receiving high-dose oxytocin. Oxytocin was used for labor augmentation in 1167 and induction in 634 women. Twenty- and 40-minute dosage intervals were compared. The study period was based on an 80% likelihood of detecting 5 and 10% differences in the cesarean and hyperstimulation rates, respectively. Statistics were analyzed with chi 2, Fisher, and Wilcoxon rank-sum tests where appropriate. Multivariate logistic regression and analysis of covariance were used to control for confounding demographic variables.

RESULTS

Comparison of the 20- and 40-minute regimens for labor induction yielded no differences in the rates of cesarean delivery for dystocia (16 versus 19%) or fetal distress (5 versus 6%). The 20-minute regimen for augmentation was associated with a significant reduction in cesarean for dystocia (8 versus 12%; P = .05). The incidence of uterine hyperstimulation was greater with the 20-minute than the 40-minute regimen for induction (40 versus 31%; P = .02), but not for augmentation (31 versus 28%). Neonatal outcomes were unaffected by the dosage interval for both augmentation and induction.

CONCLUSION

A 40-minute dosing interval for high-dose oxytocin offers no clear advantage over a 20-minute interval. Both regimens were safe and efficient, with no differences in perinatal outcome. The 20-minute interval was associated with fewer cesareans for dystocia when used for labor augmentation, whereas the 40-minute interval resulted in less hyperstimulation when used for labor induction.

Down-regulation of tumor necrosis factor expression by pentoxifylline in cancer patients: a pilot study

The wasting syndrome (cachexia) characterized by anorexia, malaise, and weight loss is observed in many patients with cancer or chronic infection. The excessive levels of tumor necrosis factor-alpha (TNF)/cachectin reported in 50% of cancer patients exhibiting clinically active disease may therefore mediate, at least in part, the cachexia associated with malignancy. Pentoxifylline, a substituted methylxanthine approved for treatment of intermittent claudication, has been shown in preclinical studies to down-regulate TNF RNA expression as well as TNF activity. We report that pentoxifylline suppressed TNF RNA levels on all three occasions in patients with initially elevated levels of TNF RNA. Pentoxifylline did not suppress TNF RNA to subnormal levels in all five patients with initially normal TNF RNA levels. Four patients reported an increased sense of well-being, improved appetite and ability to perform the activities of daily living. Two of these five patients with normal TNF levels each had a weight gain of more than 5% after 3 weeks of pentoxifylline therapy suggesting that, although TNF may be important in the pathogenesis of cancer cachexia, other anorexia-producing cytokines that are potentially affected by pentoxifylline may also be involved. No severe adverse effects were observed. Taken together these findings suggest that pentoxifylline can down-regulate TNF expression and improve the sense of well-being in cancer patients. A larger study with a randomized, double-blind, placebo-controlled design and more sophisticated estimates of quality of life will be needed to confirm these observations.

Birth weight threshold for postponing preterm birth

OBJECTIVE

The study was designed to determine the birth weight threshold at which obstetric efforts intended to delay delivery might potentially improve rates of neonatal morbidity and mortality among pregnancies delivered after spontaneous preterm labor or rupture of the membranes.

STUDY DESIGN

We studied 1147 singleton infants with birth weights between 1000 and 2499 gm and whose only complication was spontaneous preterm labor or preterm rupture of the membranes. The Mantel-Haenszel chi 2 statistic was used to evaluate trends for neonatal mortality and several indexes of morbidity.

RESULTS

The birth weight threshold for neonatal mortality was 1600 gm (p < 0.001). For neonatal morbidity the threshold was between 1600 and 1900 gm (p < 0.008).

CONCLUSION

Aggressive obstetric attempts to prevent preterm birth for infants whose weights exceed 1900 gm offers few apparent potential benefits.

Involvement of reactive oxygen intermediates in the induction of c-jun gene transcription by ionizing radiation

Previous work has demonstrated that the cellular response to ionizing radiation includes transcriptional activation of the c-jun gene. The signaling events responsible for this response, however, remain unclear. The present studies have examined the effects of ionizing radiation on c-jun expression in a variant of HL-60 cells, designated HL-525, which is deficient in protein kinase C (PKC)-mediated signal transduction. The results demonstrate that these cells express low levels of PKC alpha and PKC beta transcripts and exhibit an attenuated induction of c-jun expression following treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA). In contrast, HL-525 cells respond to ionizing radiation with an increase in c-jun mRNA which is more pronounced than that in wild-type HL-60 cells. These cells similarly respond to ionizing radiation with increased expression of the jun-B, jun-D, c-fos, and fos-B genes. Nuclear run-on assays demonstrate that X-ray-induced c-jun expression in HL-525 cells is regulated by increases in the rate of c-jun gene transcription. Moreover, mRNA stability studies in irradiated HL-525 cells demonstrate that the half-life of c-jun transcripts is prolonged compared to that in wild-type cells. Studies with N-acetyl-L-cysteine (NAC), an antioxidant, suggest that X-ray-induced transcriptional activation of the c-jun gene is mediated at least in part through the formation of reactive oxygen intermediates (ROIs). In this context, H2O2 also induced c-jun expression in HL-525 cells, and this effect was inhibited by NAC.(ABSTRACT TRUNCATED AT 250 WORDS)

Transcriptional regulation of cytokine expression by diethyldithiocarbamate in human HL-60 promyelocytic leukemia cells

Diethyldithiocarbamate (DDTC) is an investigational agent used to ameliorate chemotherapy- or radiotherapy-induced myelosuppression. We studied the effects of DDTC on the regulation of hematopoietic cytokine production in human myeloid cells. The results demonstrated that DDTC decreases proliferation of human HL-60 promyelocytic leukemia cells in a concentration-dependent manner. DDTC treatment also increased interleukin-alpha (IL-1 alpha), IL-1 beta, and tumor necrosis factor (TNF) expression in these cells. Similar findings were obtained in normal human peripheral blood monocytes. Peak induction of these cytokines occurred 6-12 hr after exposure to DDTC; levels returned to those in control cells by 24-48 hr in HL-60 cells. This effect was specific for IL-1 and TNF in that there was no detectable increase in IL-3, macrophage colony-stimulating factor or granulocyte/macrophage colony-stimulating factor RNA expression. Transcriptional run-on analysis demonstrated that exposure to DDTC increased the rate of TNF gene transcription in HL-60 cells. These data suggest that the myeloprotective effects of DDTC may be mediated, at least in part, by the induction of TNF, IL-1 alpha, and IL-1 beta.

High- versus low-dose oxytocin for labor stimulation

The number of cesarean births for dystocia has increased dramatically in the United States. Central to the management of dystocia is correction of ineffective labor by oxytocin administration, and contemporary obstetric practice is to stimulate labor with a low-dose oxytocin regimen. We prospectively compared a low-dose oxytocin regimen (1-mU/minute dosage increments) with a high-dose regimen (6-mU/minute dosage increments) in 2788 consecutive singleton cephalic pregnancies. The low-dose regimen was used first for 5 months in 1251 pregnancies, and the high-dose regimen in 1537 pregnancies during the subsequent 5 months. Indications for oxytocin stimulation were divided into augmentation (N = 1676) and induction (N = 1112). Labor stimulation was more than 3 hours shorter (P less than .0001) with the high-dose oxytocin regimen and associated with a reduction in neonatal sepsis (0.2 versus 1.3%; P less than .01). Uterine hyperstimulation was more common (55 versus 42%; P less than .0001) with the high-dose regimen, but no adverse fetal effects were observed. High-dose augmentation resulted in significantly fewer forceps deliveries (12 versus 16%; P = .03) and fewer cesareans for dystocia (9 versus 12%; P = .04). Similarly, failed induction was less frequent with high-dose compared with low-dose oxytocin (14 versus 19%; P = .05). Although the high-dose induction regimen was associated with a significantly increased cesarean incidence for fetal distress (6 versus 3%; P = .05), the incidence of umbilical artery cord blood acidemia was not increased in this subset. Induction of labor with high-dose oxytocin is problematic because of risk-benefit considerations. Although induction failed less frequently with the high-dose regimen, cesarean for fetal distress was performed more frequently. In contrast, high-dose oxytocin to augment ineffective spontaneous labor minimized the number of cesareans done for dystocia.

Chorioamnionitis: a harbinger of dystocia

The impact of chorioamnionitis on the course of labor is controversial. Some clinicians believe the infection has stimulatory effects, whereas others suspect inhibitory influences. Two hundred sixty-six pregnancies with chorioamnionitis requiring labor stimulation with oxytocin were matched to uninfected women for maternal age, race, parity, gestational age, oxytocin dosage regimen, indication for labor stimulation, type of labor stimulation, cervical dilatation at initiation of oxytocin, and time for rupture of membranes to initiation of labor stimulation. Chorioamnionitis diagnosed before oxytocin infusion was associated with shorter oxytocin initiation-to-delivery intervals (4.3 versus 5.6 hours; P = .04) and had no significant impact on the cesarean rate compared with matched controls. In contrast, pregnancies complicated by chorioamnionitis detected late in labor were associated with markedly longer oxytocin initiation-to-delivery intervals (12.6 versus 7.9 hours; P less than .0001) and a fourfold increase in cesarean for dystocia compared with matched controls (40 versus 10%; P less than .0001). Thus, the impact of chorioamnionitis on the course of labor can be divided into two clinical presentations. That diagnosed before labor stimulation does not increase the use of cesarean, whereas that diagnosed after oxytocin stimulation may be a sign of abnormal labor, as it was associated with a marked increase in abdominal delivery for dystocia.

Factors affecting the dose response to oxytocin for labor stimulation

For nearly 40 years synthetic oxytocin has been used for labor stimulation by titrating dosage rate to uterine contractions. We used a computerized data base to determine variables affecting the dose response to oxytocin in 1773 pregnancies. Statistically important predictors of required oxytocin dosage included cervical dilatation, parity, and gestational age. Maternal body surface area was found to be associated with a higher oxytocin dosage in women undergoing induction of labor. However, the broad range of the statistical confidence intervals precluded prediction of a given pregnancy's oxytocin requirement.

Functional expression of the macrophage colony-stimulating factor receptor in human THP-1 monocytic leukemia cells

Macrophage colony-stimulating factor (M-CSF) is required for the proliferation, differentiation, and activation of monocytes. High-affinity receptors for M-CSF are encoded by the c-fms proto-oncogene. In the present study, we show that c-fms transcripts are detectable in human THP-1 myeloid leukemia cells. Furthermore, radiolabeled 125I-M-CSF is rapidly internalized into THP-1 cells and then degraded intracellularly. The results also show that treatment of THP-1 cells with M-CSF is associated with the activation of protein kinase C (PKC) and the induction of tumor necrosis factor (TNF) gene expression. TNF transcript levels were low to undetectable in uninduced THP-1 cells, reached maximal levels by 1 hour of exposure to M-CSF, and returned to those of control cells by 24 hours. Transcriptional run-on analysis showed that a low level of TNF transcription is detectable in untreated THP-1 cells, and M-CSF treatment increased the rate of TNF transcription. Pretreatment of THP-1 cells with pertussis toxin inhibited the increase in PKC activity but not the induction of TNF transcripts by M-CSF. Moreover, exposure of THP-1 cells to inhibitors of protein kinase activity blocked the increase in TNF messenger RNA. These findings suggest that at least two M-CSF-mediated signaling pathways exist in THP-1 cells and that the induction of TNF may be regulated by a protein kinase-dependent mechanism distinct from PKC.

Macrophage colony-stimulating factor gene expression in vascular cells and in experimental and human atherosclerosis

The infiltration of monocytes into the vascular wall and their transformation into lipid-laden foam cells characterizes early atherogenesis. Macrophages are also present in more advanced human atherosclerotic plaques and can produce many mediators that may contribute to lesion formation and progression. Macrophage colony-stimulating factor (MCSF) enhances the proliferation and differentiation of monocyte progenitors and is required for the survival and activation of mature monocytes and macrophages. The authors therefore examined the expression of the MCSF gene in cultured human vascular endothelial (EC) and smooth muscle cells (SMC) as well as in atheromatous lesions from rabbits and humans. Growth arrested EC and SMC contain a low level of MCSF mRNA. Bacterial lipopolysaccharide (LPS), recombinant human interleukin-1 alpha (IL-1 alpha) or tumor necrosis factor alpha (TNF alpha) induced MCSF mRNA accumulation in a concentration-dependent manner in both EC and SMC. These stimuli induced large increases in MCSF mRNA with peak induction between 4-8 hours after treatment. LPS, IL-1 alpha, and TNF alpha stimulated EC and SMC also showed increased fluorescent antibody staining for MCSF protein and released immunoreactive MCSF in a time-dependent manner. In contrast, phorbol 12-myristate 13-acetate (PMA) was a less potent inducer of MCSF gene expression and iron-oxidized low-density lipoproteins (ox-LDL) did not increase consistently MCSF mRNA or the synthesis and secretion of immunoreactive protein. Northern analysis of mRNA isolated from the atheromatous aorta of rabbits fed a 1% cholesterol diet for 10 weeks showed elevated MCSF mRNA compared with controls. Immunostaining of atheromatous arterial lesions of rabbits demonstrated MCSF protein in association with intimal SMC as well as macrophages. Furthermore, polymerase chain reaction (PCR) analysis of MCSF mRNA in human atheromata showed higher levels than found in nonatherosclerotic arteries and veins. Since the authors found no mRNA for the MCSF receptor, c-fms, in cultured EC or SMC macrophages are likely the primary target for MCSF within atheromatous vessels. The authors therefore investigated the effects of MCSF on monocyte functions related to foam cell development. Treatment of cultured human monocytes with recombinant human MCSF (10(3) U/ml, 72 hr) led to the accumulation of mRNA for the acetyl-LDL (scavenger) receptor and apolipoprotein E (apo E). These studies establish that vascular EC and SMC produce substantial MCSF in response to a variety of stimuli. The local production of MCSF during atherogenesis may contribute to macrophage survival and proliferation or activate specific macrophage functions such as expression of the scavenger receptor and secretion of apo E.

Maternal and perinatal effects of hypertension at term

This study sought to determine if selected maternal and fetal outcomes in term singleton pregnancies complicated by hypertension during labor differed from those without this complication. All pregnancies delivered at Parkland Memorial Hospital, Dallas, Texas, during 1986 were ascertained using a computerized database. A total of 11,812 term singleton pregnancies ended in delivery during the study period; 1,392 (12%) were complicated by hypertension. Women with a total of 1,383 of these hypertensive pregnancies presented to the hospital with a live fetus. Hypertension was diagnosed in 984 (19%) of the 5,060 primiparous and 399 (6%) of the 6,752 parous women. Hypertension during labor in term singleton pregnancies is associated with increased maternal risks because of the potential complications associated with interventions necessary for successful management. Moreover, hypertension in such pregnancies also increases the perinatal mortality rate. However, this increased rate results from a higher likelihood that fetal death will occur prior to the patient's presentation to the hospital. The risk of fetal morbidity and mortality appears to be low in the hypertensive woman with a term pregnancy admitted to the hospital with a live fetus.

Inhibition of protein kinase C is associated with a decrease in c-myc expression in human myeloid leukemia cells

Treatment of human myeloid leukemic cells with phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with activation and then partial down-regulation of protein kinase C activity. Previous work has suggested that the activation of protein kinase C by TPA contributes to the decrease in c-myc expression during differentiation of these cells. The present studies demonstrate that the decline in c-myc mRNA levels following exposure of HL-60 cells to TPA is preceded by an increase in expression of this gene. In contrast, exposure of HL-60 cells to inhibitors of protein kinase C activity is associated with down-modulation of c-myc expression. Similar findings have been obtained in U-937 myeloid leukemia cells. Taken together, these findings suggest that phorbol esters have a biphasic effect on c-myc expression. Whereas the activation of protein kinase C by phorbol esters may be associated with an increase in c-myc gene expression, the subsequent partial down-regulation of kinase activity may initiate a cascade of events resulting in the down-modulation of c-myc expression.

Mechanisms of X-ray-mediated protooncogene c-jun expression in radiation-induced human sarcoma cell lines

c-jun is a protooncogene associated with neoplastic transformation and is transcriptionally induced by ionizing radiation. To examine the possible mechanisms of radiation-induced c-jun transcription, we analyzed RNA from human tumor cell lines RIT-3 and STSAR-5 following x-irradiation in the presence of protein kinase inhibitors, or the absence of serum and calcium. Protooncogene c-jun expression increased several fold following irradiation of these radiation-induced human sarcoma cell lines. The expression of c-jun was not altered following irradiation in conditioned medium containing serum as compared to that of cells in serum free medium. Depletion of PKC by prolonged TPA treatment resulted in inhibition of c-jun expression. In addition, nonspecific protein kinase inhibitors, staurosporin and H7 attenuated c-jun expression, whereas the analogue of ATP (sangivamycin) did not. Furthermore, the selective inhibitor of cAMP dependent protein kinase HA 1004 did not alter radiation-mediated c-jun induction. These data indicate that ionizing radiation exposure results in c-jun induction which is dependent upon the activation of PKC. Protein kinase C activation and the subsequent expression of the protooncogene c-jun by ionizing radiation may further define the molecular mechanisms of radiation-induced neoplastic transformation.

Tumor necrosis factor gene expression is mediated by protein kinase C following activation by ionizing radiation

Tumor necrosis factor (TNF) production following X-irradiation has been implicated in the biological response to ionizing radiation. Protein kinase C (PKC) is suggested to participate in TNF transcriptional induction and X-ray-mediated gene expression. We therefore studied radiation-mediated TNF expression in HL-60 cells with diminished PKC activity produced by either pretreatment with protein kinase inhibitors or prolonged 12-O-tetradecanoylphorbol-13-acetate treatment. Both treatments resulted in attenuation of radiation-mediated TNF induction. Consistent with these results, we found no detectable induction of TNF expression following X-irradiation in the HL-60 variant deficient in PKC-mediated signal transduction. The rapid activation of PKC following gamma-irradiation was established using an in vitro assay measuring phosphorylation of a PKC specific substrate. A 4.5-fold increase in PKC activity occurred 15 to 30 s following irradiation, which declined to baseline at 60 s. Two-dimensional gel electrophoresis of phosphoproteins extracted from irradiated cells demonstrated in vivo phosphorylation of the PKC specific substrate Mr 80,000 protein at 45 s following X-irradiation. These findings indicate that signal transduction via the PKC pathway is required for the induction of TNF gene expression by ionizing radiation.

Ionizing radiation induces expression and binding activity of the nuclear factor kappa B

Recent studies have demonstrated that treatment of mammalian cells with ionizing radiation is associated with activation of gene expression. Although the signal transduction pathways stimulated by ionizing radiation remain unclear, our previous findings indicate that radiation induces specific genes at the transcriptional level. The present work has examined the effects of ionizing radiation on the transcription factor NF-kappa B. The results demonstrate that ionizing radiation activates DNA binding of nuclear factor (NF)kappa B. This effect was detectable at 2 grays (Gy) and reached a maximum at 5-20 Gy. At a dose of 20 Gy, the increase in NF-kappa B binding activity was maximal at 2-4 h and then declined to pretreatment levels. The results also demonstrate that ionizing radiation transiently increases NF-kappa B mRNA levels. However, the finding that induction of NF-kappa B binding to DNA occurs in the presence of cycloheximide indicates that ionizing radiation activates preexisting NF-kappa B protein. NF-kappa B exists as a cytoplasmic protein before activation. Thus, our results suggest that ionizing radiation induces transduction pathways which include cytoplasmic signaling events.

Effects of hexamethylene bisacetamide on induction of monocytic differentiation of human U-937 myeloid leukemia cells

The present studies have examined the effects of hexamethylene bisacetamide (HMBA) on the human U-937 monocytic cell line. HMBA treatment was associated with: (1) decreases in U-937 cell proliferation, (2) increases in nonspecific esterase activity and cell surface antigen expression consistent with monocytic differentiation, (3) decreases in c-myc gene expression, and (4) induction of tumor necrosis factor (TNF) transcripts. Treatment of U-937 cells with HMBA was also associated with increases in phospholipase A2 activity and increases in the release of arachidonic acid and its metabolites. Dexamethasone, an agent previously shown to inhibit monocytic differentiation, had no detectable effect on the down-regulation of c-myc, but blocked the induction of TNF expression. Taken together, the results demonstrate that HMBA induces monocytic differentiation of U-937 cells and that this effect is sensitive, in part, to dexamethasone.

Regulation of jun-B expression by a cyclic AMP (cAMP)-dependent mechanism in human myeloid cells

The present studies have examined the regulation of the jun-B early response gene by cyclic AMP (cAMP)-dependent signaling pathways. The 2.0-kb jun-B transcript was at low but detectable levels in uninduced human HL-60 myeloid leukemia cells. In contrast, treatment with 1 mmol/L8-bromo-adenosine 3',5'-cyclic monophosphate (8-Br-cAMP) in the presence of isobutylmethylxanthine, an inhibitor of cAMP-dependent phosphodiesterase, was associated with increases in jun-B transcripts that were maximal by 1 hour and then decreased to near pretreatment levels by 6 hours. Similar findings were obtained with 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (8-CPT-cAMP) and N6,2'-0-dibutyryladenosine 3',5'-cyclic monophosphate (dBt-cAMP). jun-B transcripts were also increased with other agents that increase intracellular cAMP levels, such as prostaglandin E2 (PGE2) and forskolin. Moreover, inhibition of cAMP-dependent protein kinase by the isoquinolinesulfonamide H-8 blocked 8-Br-cAMP-induced increases in jun-B expression. The results of nuclear run-on assays demonstrate that treatment of HL-60 cells with PGE2, forskolin, 8-Br-cAMP, and dBt-cAMP is associated with increases in the rate of jun-B transcription. The present findings also demonstrate that the related jun-D gene is similarly regulated by a cAMP-dependent pathway. Taken together, these findings suggest that stimulation of cAMP-dependent protein kinase is involved in the induction of jun gene expression in myeloid leukemia cells.

Posttranscriptional regulation of the zinc finger-encoding EGR-1 gene by granulocyte-macrophage colony-stimulating factor in human U-937 monocytic leukemia cells: involvement of a pertussis toxin-sensitive G protein

The EGR-1 gene is an immediate early response gene encoding a zinc finger DNA-binding protein. The present studies have examined the regulation of EGR-1 gene expression in human U-937 monocytic leukemia cells treated with granulocyte-macrophage colony-stimulating factor (GM-CSF). The results demonstrate that GM-CSF rapidly and transiently increases EGR-1 gene expression in U-937 cells. Similar findings were obtained in GM-CSF-treated human monocytes. We also show that the regulation of EGR-1 expression by GM-CSF is a pertussis toxin-sensitive event. The results of nuclear run-on assays further demonstrate that the EGR-1 gene is constitutively transcribed in untreated U-937 cells and that GM-CSF has little effect on this rate of transcription. Inhibition of protein synthesis with cycloheximide also had no detectable effect on EGR-1 gene transcription but was associated with superinduction of EGR-1 mRNA levels in GM-CSF-treated cells. Moreover, the half-life of GM-CSF-induced EGR-1 transcripts was prolonged from 33 to 70 min following inhibition of protein synthesis. Taken together, the results indicate that GM-CSF activates signaling pathways which regulate EGR-1 gene expression through a pertussis toxin-sensitive G protein and that these events increase EGR-1 mRNA levels by a posttranscriptional mechanism. This GM-CSF-dependent regulation of EGR-1 expression may provide a mechanism for transducing signals to the nucleus that are involved in the control of gene transcription.

Elective hospitalization in the management of twin pregnancies

We sought to evaluate the effectiveness of a policy of early elective hospitalization on the outcomes of 522 consecutive twin gestations delivered at our institution between 1983-1987. During the first 2 years (1983-1985), 237 twin pregnancies were delivered with a policy of elective hospitalization when twin pregnancy was diagnosed between 24-32 weeks' gestation. When possible, elective hospitalization started at 24 weeks' gestation. Electively admitted women remained hospitalized until 34 weeks' gestation, at which time they were discharged unless complications developed requiring continued hospitalization. During 1985-1987, 285 women with twin gestations were intentionally managed as outpatients unless intercurrent complications required hospitalization. A total of 211 twin pregnancies was excluded from analysis because the women did not present for prenatal care (19%) or were undiagnosed until delivery (22%). Of the remaining 311 pregnancies available for study, 134 were managed when the elective admission policy prevailed and 177 when this policy was not in effect. Although the elective admission policy did result in a small reduction in the incidence of low birth weight among the 58 pregnancies hospitalized electively (mean [+/- SEM] gestational age at elective hospitalization 27.7 +/- 0.3 weeks) compared with outpatient management, this policy did not result in an improvement in prematurity (32 versus 36%; P greater than .05) or perinatal morbidity as reflected by requirement for neonatal intensive care (12 versus 11%; P greater than .05) and mechanical ventilation (8 versus 9%; P greater than .05). Moreover, perinatal mortality was actually higher in the electively hospitalized pregnancies (8 versus 2%; P = .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of tumor necrosis factor gene expression by ionizing radiation in human myeloid leukemia cells and peripheral blood monocytes

Previous studies have demonstrated that ionizing radiation induces the expression of certain cytokines, such as TNF alpha/cachectin. However, there is presently no available information regarding the molecular mechanisms responsible for the regulation of cytokine gene expression by ionizing radiation. In this report, we describe the regulation of the TNF gene by ionizing radiation in human myeloid leukemia cells. The increase in TNF transcripts by x rays was both time- and dose-dependent as determined by Northern blot analysis. Similar findings were obtained in human peripheral blood monocytes. Transcriptional run-on analyses have demonstrated that ionizing radiation stimulates the rate of TNF gene transcription. Furthermore, induction of TNF mRNA was increased in the absence of protein synthesis. In contrast, ionizing radiation had little effect on the half-life of TNF transcripts. These findings indicate that the increase in TNF mRNA observed after irradiation is regulated by transcriptional mechanisms and suggest that production of this cytokine by myeloid cells may play a role in the pathophysiologic effects of ionizing radiation.

Biological consequences of gene regulation after ionizing radiation exposure

Ionizing radiation is a ubiquitous environmental mutagen and carcinogen widely used in cancer therapy. However, little is known about the induction of cellular signaling events and specific gene expression after radiation exposure. We review the accumulating evidence that ionizing radiation induces signal transduction pathways involving activation of protein kinase C and a program of genetic events that may contribute to the biological effects of x rays.

Protein kinase C mediates x-ray inducibility of nuclear signal transducers EGR1 and JUN

The cellular response to ionizing radiation includes growth arrest and DNA repair followed by proliferation. Induction of immediate early response genes may participate in signal transduction preceding these phenotypic responses. We analyzed mRNA expression for different classes of immediate early genes (JUN, EGR1, and FOS) after cellular x-irradiation. Increased expression of the EGR1 and JUN genes was observed within 0.5-3 hr following x-ray exposure. Preincubation with cycloheximide was associated with superinduction of JUN and EGR1 in x-irradiated cells. Inhibition of protein kinase C activity by prolonged stimulation with phorbol 12-myristate 13-acetate or the protein kinase inhibitor H7 prior to irradiation attenuated the increase in EGR1 and JUN transcripts. FOS expression was not coregulated with that of EGR1 following x-irradiation, suggesting a distinct regulatory pathway of this gene as compared with its regulation following serum and phorbol ester. These data implicate the EGR1 and JUN proteins as signal transducers during the cellular response to radiation injury and suggest that this effect is mediated in part by a protein kinase C-dependent pathway.

Expression of the jun-B gene during induction of monocytic differentiation

The AP-1 protein complex binds to specific DNA sequences that regulate transcription of genes responsive to certain growth factors and phorbol esters. This complex is composed of products of the jun and fos gene families. The present studies have examined the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on the regulation of jun-B gene expression during induction of monocytic differentiation. Low levels of jun-B transcripts were present in uninduced HL-60 promyelocytic leukemia cells. In contrast, treatment with TPA was associated with rapid increases in jun-B mRNA levels that were maximal at 3 h and remained elevated at 48 h. The induction of jun-B expression by TPA in these cells preceded that of the c-jun and c-fos genes. Similar increases in jun-B transcripts were detectable in TPA-treated THP-1 and U-937 myeloid leukemia cells, although expression of this gene was transient in the more differentiated THP-1 cells. Run-on assays demonstrated low levels of jun-B gene activation in untreated HL-60 cells, whereas TPA treatment was associated with a 6-fold increase in the transcription rate of this gene. This induction of jun-B expression occurred in the absence of de novo protein synthesis. In contrast, inhibition of protein synthesis was associated with superinduction of TPA-induced jun-B mRNA levels and an increase in stability of this transcript. These findings suggest that jun-B gene expression is regulated at both the transcriptional and posttranscriptional levels during induction of monocytic differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of c-jun gene expression by cAMP in HL-60 myeloid leukemia cells

Previous studies have demonstrated that expression of the c-jun proto-oncogene is induced by phorbol esters and other agents that activate protein kinase C. The present work has examined the involvement of cAMP-dependent signaling mechanisms in the regulation of c-jun gene expression. Low levels of c-jun transcripts were detectable in untreated HL-60 myeloid leukemia cells. In contrast, treatment of these cells with 8-bromoadenosine 3',5'-cyclic monophosphate was associated with increases in c-jun expression that were maximal at 3 h and then declined to pretreatment levels. Similar findings were obtained with N6,2'-O-dibutyryladenosine 3',5'-cyclic monophosphate and 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate, but not with 8-bromoguanosine 3',5'-cyclic monophosphate. c-jun transcripts were also increased with agents, such as prostaglandin E2 and forskolin, that increase intracellular cAMP levels. The effects of these agents on c-jun expression were associated with activation of cAMP-dependent protein kinase. Moreover, inhibition of this kinase activity with the isoquinolinesulfonamide derivative H8 was associated with a block in the induction of c-jun expression by cAMP. Nuclear run-on analysis further demonstrated that while c-jun transcription is a low levels in untreated HL-60 cells, treatment with cAMP analogs is associated with an increase in the transcriptional rate of this gene. Taken together, these findings suggested that, in addition to activation of protein kinase C, stimulation of cAMP-dependent protein kinase activity is also involved in the transcriptional induction of c-jun gene expression. The present results similarly demonstrate that c-fos gene transcription is induced in HL-60 cells through a mechanism involving cAMP-dependent protein kinase activity. Since heterodimers of the Jun and Fos proteins have been shown to bind to the phorbol ester-responsive element (AP-1-binding site), the present findings indicate that cAMP-induced signaling events may also regulate gene transcription through formation of Fos/Jun heterodimers and that interaction between phorbol ester- and cAMP-dependent pathways could occur through induction of the c-jun gene in these cells.

Progress of fibrinolysis during tumor necrosis factor infusions in humans. Concomitant increase in tissue-type plasminogen activator, plasminogen activator inhibitor type-1, and fibrin(ogen) degradation products

Several investigators have reported that tumor necrosis factor (TNF) can alter the production of plasminogen activator type-1 (PAI-1) and plasminogen activators (PAs) by endothelial cells in vitro. We have examined the in vivo effects of recombinant human TNF administration on fibrinolysis as assessed by parameters in plasma during a 24-hour period of continuous TNF infusion to 17 cancer patients with active disease. The plasma levels of PAI activity increased sevenfold after 3 and 24 hours of TNF infusion. This was the result of an increase of PAI-1 antigen; PAI-2 antigen was not detectable. Plasma concentrations of tissue-type PA (t-PA) antigen increased twofold to fivefold after 3 and 24 hours of TNF infusion, whereas urokinase-type PA antigen levels in plasma remained unaltered. After 3 hours of TNF infusion the plasma levels of alpha 2-antiplasmin were slightly decreased, 5% on average, suggesting that fibrinolysis continued. After 24 hours of TNF infusion a highly significant increase in fibrin- plus fibrinogen-degradation products, and separately of fibrin degradation products and fibrinogen degradation products, was found. This indicates that fibrinolysis persisted, at least partly, in the presence of high levels of PAI activity. Whereas PAI-1 production increased, t-PA production by human endothelial cells in vitro remains unaltered or even decreases on TNF addition. It has been shown previously that TNF infusion in our patients results in thrombin and fibrin generation. Therefore, it is possible that thrombin, not TNF, is the actual stimulus for t-PA production in our patients. We speculate that fibrin is formed during TNF infusions and that plasmin is generated by t-PA action immediately on the initial formation of (soluble) fibrin molecules. Such a process may explain the generation of degradation products of both fibrin and fibrinogen during infusion of TNF in patients.

Phospholipase A2 activation and autoinduction of tumor necrosis factor gene expression by tumor necrosis factor

Tumor necrosis factor (TNF) acts via a cell surface receptor to induce a variety of cellular events including cytolysis, differentiation, and mitogenesis. The mechanisms underlying the cell specific actions of TNF are not known. In the present study, postreceptor events associated with the autoinduction of TNF expression were examined in HL-60 cells. There was no detectable alteration in phospholipase C activity as measured by inositol phosphate generation or release of choline metabolites following TNF stimulation. However, TNF increased the release of arachidonic acid metabolites from HL-60 cells. This increase in arachidonic acid metabolism was associated with a 40% increase in phospholipase A2 activity. Furthermore, the release of arachidonic acid metabolites was blocked by inhibitors of phospholipase A2. Taken together, these findings indicated that TNF stimulates phospholipase A2 and arachidonic acid metabolism in HL-60 cells. The results also demonstrate that TNF expression is induced 15-30 min after stimulation with TNF and that this effect is associated with an increase in the rate of TNF transcription. This autoinduction of TNF mRNA was blocked by inhibitors of phospholipase A2. While the cyclooxygenase inhibitor indomethacin had no detectable effect, ketoconazole and nordihydroguaiaretic acid, inhibitors of lipoxygenase, also blocked the induction of TNF expression by TNF. These findings suggest that phospholipase A2 and lipoxygenase activity are required for the transcriptional activation of TNF gene expression associated with TNF stimulation of HL-60 cells.

Transcriptional regulation of c-jun gene expression by arabinofuranosylcytosine in human myeloid leukemia cells

Previous studies have demonstrated that 1-beta-D-arabinofuranosylcytosine (ara-C) induces terminal differentiation of human myeloid leukemia cells. Other studies have shown that the c-jun protooncogene is expressed during phorbol ester-induced myeloid differentiation. This work examines the effects of ara-C on c-jun gene expression in human KG-1 myeloid leukemia cells. The results demonstrate that c-jun transcripts are undetectable in uninduced KG-1 cells and that ara-C induces expression of this gene in a concentration- and time-dependent manner. Ara-C treatment was also associated with increases in c-jun transcripts in U-937, THP-1, and HL-60 myeloid leukemia cells. Furthermore, transcriptional run-on analysis has demonstrated that exposure to ara-C increases the rate of c-jun gene transcription. The results also demonstrate that while inhibition of protein synthesis superinduces c-jun mRNA levels in phorbol ester-treated KG-1 cells, cycloheximide had no effect on the induction of c-jun transcripts during ara-C treatment. Moreover, the half-life of c-jun transcripts in ara-C-treated KG-1 cells was 42 min. These findings suggest that the increase in c-jun mRNA observed during ara-C treatment is regulated by a transcriptional mechanism, and that c-jun may be involved in the induction of differentiation and regulation of gene expression by ara-C.

Induction of monocytic differentiation by tumor necrosis factor in phorbol ester-resistant KG-1a cells

Tumor necrosis factor (TNF) is a regulatory cytokine that has pleiotropic effects on hematopoietic cell growth and differentiation. The present studies have examined the effects of TNF on the differentiation of phorbol-ester resistant human KG-la leukemia cells. Treatment with 100 U/mL of TNF or 33 nM 12-O-tetradecanoylphorbol-13-acetate (TPA) had no detectable effect on the growth of KG-1a cells. In contrast, TNF, but not TPA, induced cellular aggregation and expression of the ICAM-1 adhesion molecule in KG-1a cells. Furthermore, KG-1a cells responded to TNF, but not to TPA, with a partial down-regulation of c-myc mRNA levels and induction of M-CSF gene transcription. Previous work suggested that TNF induces M-CSF gene expression through activation of phospholipase A2 and eicosanoid production. The present studies also demonstrate that TNF stimulated phospholipase A2 activity. In contrast, there was no detectable increase in phospholipase A2 activity following TPA treatment. These results indicate that: 1) certain characteristics of the differentiated monocytic phenotype were induced by TNF in the phorbol ester-resistant KG-1a line, and 2) treatment with TNF and not TPA was associated with activation of phospholipase A2 during induction of monocytic differentiation in these cells.

Inhibition of phorbol ester-induced monocytic differentiation and c-fms gene expression by dexamethasone: potential involvement of arachidonic acid metabolites

The treatment of human U-937 leukemia cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with induction of monocytic differentiation. However, the signaling pathways responsible for induction of the differentiated monocytic phenotype remain unclear. The present studies demonstrate that dexamethasone blocks TPA-induced U-937 cell growth inhibition, adherence, and alpha-naphthyl acetate esterase staining. The results also demonstrate that dexamethasone inhibits the appearance of c-fms transcripts associated with TPA treatment. Run-on transcription assays demonstrated that the c-fms gene is transcriptionally active in uninduced U-937 cells and that the rate of transcription is unchanged after dexamethasone and/or TPA treatment. These findings indicated that TPA increases c-fms expression by a dexamethasone-sensitive posttranscriptional mechanism. Treatment of U-937 cells with TPA was also associated with stimulation of arachidonic acid metabolism. Furthermore, dexamethasone, an inhibitor of phospholipase A2 activity, blocked TPA-induced increases in arachidonic acid release. These findings suggested that TPA may regulate certain features of monocytic differentiation, such as c-fms gene expression, through the formation of arachidonic acid metabolites. Indomethacin, an inhibitor of cyclooxygenase, had no detectable effect on c-fms gene expression. However, the cyclooxygenase metabolite, prostaglandin E2, inhibited the TPA-induced increases in c-fms mRNA levels. Taken together, the results indicate that TPA regulates c-fms gene expression by a dexamethasone-sensitive mechanism and that c-fms mRNA levels are controlled by metabolites of the arachidonic acid pathway.