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PubMed2003

A randomized controlled trial of outpatient versus inpatient labour induction with vaginal controlled-release prostaglandin-E2: effectiveness and satisfaction.

BACKGROUND: Outpatient management in obstetrics is expanding, but evidence to support outpatient labour induction is needed. OBJECTIVE: To compare the effectiveness, acceptability, duration of hospitalization, and safety of outpatient and inpatient induction of labour with intravaginal controlled-release prosta-glandin-E2 (CR-PGE2). METHODS: A prospective, randomized, controlled trial enrolled 300 women at term with parity < or = 5 and singleton pregnancies in cephalic presentation. Each had an unscarred uterus, a normal non-stress test (NST), and a Bishop score of < or = 6. After insertion of the CR-PGE2, and 1 hour of monitoring, those in the outpatient group were discharged home, to return with onset of labour or 12 hours later for an NST. If not already in labour 24 hours later, the women returned for inpatient induction. Vaginal examination was not repeated before 24 hours unless the patient was contracting and required analgesia. Inpatients remained on the antepartum ward but were otherwise treated similarly. The women in both groups reported ratings of satisfaction, pain, and anxiety over the telephone until they were in labour. RESULTS: There were 150 women randomized to outpatient and 150 women to inpatient induction of labour. The number of women who were in labour or who delivered by 24 hours in the outpatient group was 115 (0.77, 95% confidence interval [CI] 0.70-0.84) and in the inpatient group was 107 (0.72, 95% CI 0.64-0.79). The median times to labour were 9.8 hours (95% CI, 8.1-11.4) and 11.4 hours (95% CI, 10.1-12.7), and to delivery were 21.4 hours (95% CI, 19.2-23.5) and 20.7 hours (95% CI, 18.4-23.0), for the outpatient and inpatient groups, respectively. In the outpatient group, 56% of women reported high satisfaction during the initial 12 hours of induction compared to 39% in the inpatient group (p < 0.008). Ratings of pain and anxiety during the first 12 hours of induction were similar. In the outpatient group, women were at home for a median of 8 hours (95% CI, 6.7-9.4) before labour and delivery. There were no significant differences in adverse outcomes. CONCLUSIONS: This study suggests that outpatient induction of labour with intravaginal CR-PGE2 may be a reasonable option for selected low-risk women; however, further study is needed to confirm the safety of this approach.

Administration, Intravaginal↗

PubMed2002

Effects of induction of anaesthesia with sufentanil and positive-pressure ventilation on the intra- to extrathoracic volume distribution.

BACKGROUND AND OBJECTIVE: Induction of general anaesthesia in combination with positive-pressure ventilation is often associated with a significant decrease of arterial pressure. A decreased preload may contribute to this phenomenon. The aim was to investigate whether a change in cardiac filling occurs following the induction of general anaesthesia with sufentanil under typical clinical conditions. METHODS: Fifteen patients scheduled for elective coronary bypass grafting were studied immediately before surgery. In addition to standard monitors, a transpulmonary double-indicator dilution technique measured in vivo intrathoracic blood volume, global end-diastolic volume and total circulating blood volume. For induction of anaesthesia 2 microg kg(-1) sufentanil was given. Measurements were performed awake and after the induction of anaesthesia, intubation and mechanical ventilation of the lungs. RESULTS: To maintain arterial pressure during the induction period within -20% of baseline pressure, on average 22 +/- 6mLkg(-1) crystalloids and 8 +/- 6mLkg(-1) colloids were given. Despite these amounts of fluid, cardiac filling was decreased, whereas circulating blood volume increased significantly. Both central venous pressure and pulmonary capillary wedge pressure increased. CONCLUSIONS: Induction of general anaesthesia with positive-pressure ventilation is regularly associated with a blood volume shift from intra- to extrathoracic compartments. Even in low-dose opioid monoanaesthesia with sufentanil--often regarded as relatively inert in haemodynamic terms--the phenomenon could be demonstrated as the primary cause of the often-observed decrease of arterial pressure. It seems, therefore, rationally justified to restore cardiac filling by generous administration of intravenous fluids, at least in patients with unaffected cardiac pump function. During induction of anaesthesia, central venous pressure and pulmonary capillary wedge pressure do not reliably indicate cardiac filling.

Adjuvants, Anesthesia↗

PubMed2004

Comparison of single-breath vital capacity rapid inhalation with sevoflurane 5% and propofol induction on QT interval and haemodynamics for laparoscopic surgery.

BACKGROUND AND OBJECTIVE: To compare two techniques to achieve induction of anaesthesia for laparoscopic surgery. A single-breath vital capacity rapid inhalation induction with sevoflurane was compared to intravenous propofol. Their effects on haemodynamics and the QT interval of the electrocardiogram were assessed. METHODS: Forty-four ASA I-II patients scheduled to undergo elective laparoscopic gynaecological surgery were divided into two groups. In the sevoflurane group (Group S, n = 22), general anaesthesia was induced with a single-breath vital capacity rapid inhalation of sevoflurane 5% with nitrous oxide (N2O) 65% in O2 and then anaesthesia was maintained with sevoflurane 1-1.5% with N2O 65% in O2. In the propofol group (Group P, n = 22), general anaesthesia was induced with propofol 2 mg kg(-1) intravenously and maintained with propofol 6 mg kg(-1) h(-1). Systolic, diastolic and mean arterial pressures, heart rate and end-tidal CO2 values were recorded before anaesthesia (basic value), during the induction period (time X), at 10 min (time Y) and at 30 min (time Z) of CO2 insufflation in all patients. QT intervals were calculated using Bazett's equation. RESULTS: Systolic, diastolic and mean arterial pressure values during the induction period (time X) were lower than the basic value in both groups (P < 0.05). In Group S, QTc intervals were significantly longer during the induction period (time X) and at the tenth min of CO2 insufflation (time Y) than Group P (P < 0.05). Five patients at time X and two patients at time Y developed ventricular dysrhythmias, which improved spontaneously in Group S. In Group P, there was no significant difference in QTc intervals and only one patient developed a ventricular dysrhythmia at time Y. CONCLUSIONS: Single-breath vital capacity rapid inhalation induction technique with sevoflurane can cause prolongation of the QT interval and dysrhythmias, compared with induction and maintenance of anaesthesia with propofol in laparoscopic surgery.

Adult↗

PubMed1998

Induction of p53 by the concerted actions of aziridine and quinone moieties of diaziquone.

The biologic functions attributed to the nucleophosphoprotein p53 have been increasing in recent years. Some studies suggested that wild type p53 is responsible for cell cycle arrest brought about as a response to exposure of mammalian cells to DNA-damaging agents. This cell cycle arrest occurs in order for cells to repair the damaged macromolecules. Extensively damaged cells are also thought to undergo apoptosis via the p53-dependent or -independent signal transduction pathways. In this study, we investigated the ability of diaziridinylbenzoquinones to increase p53 levels in the human breast cancer cell line MCF-7. Diaziquone (AZQ), an anticancer agent, and its derivatives, diaziridinequinone (DZQ) and methyldiaziridinequinone (MeDZQ), induced p53 in a dose- and time-dependent manner as measured by the electrophoretic mobility shift assay. Wild type p53 induction by AZQ was suppressed when DT-diaphorase activity was inhibited by pretreating the cells with dicumarol. Aside from their potent alkylating activity, these agents also undergo redox cycling as evidenced by oxygen consumption and the production of reactive oxygen species (ROS). Inhibition of ROS production by the antioxidant enzyme catalase reduced AZQ- and DZQ-mediated p53 induction by about 45%. Thiotepa, a non-quinone aziridine-containing agent, and 1,4-benzoquinone (p-BQ), a redox cycling quinone, increased p53 levels. The nonalkylator oxygen-radical-generating agent menadione (MD) caused p53 induction only when MCF-7 cells were allowed to recover in drug-free media. On the basis of these data, we propose that the bioreductive activation of AZQ is a prerequisite for p53 induction. Moreover, the induction of p53 by AZQ requires both the quinone and the aziridine moieties of the AZQ molecule. Although AZQ and its analogues increased p53 levels in MCF-7 cells, p53 induction in these cells may not be responsible for the apoptosis seen upon treatment of MCF-7 cells with these agents. The uncoupling of p53 induction and apoptosis is evidenced by the generation of nucleosomal DNA laddering in aziridinequinone-treated T47D cells, a breast cancer cell line bearing a p53 mutation.

Adenocarcinoma↗

PubMed1999

Possible improved survival of patients with stage IV AJCC melanoma receiving SRL 172 immunotherapy: correlation with induction of increased levels of intracellular interleukin-2 in peripheral blood lymphocytes.

PURPOSE: This phase I-II study was designed to assess safety and clinical efficacy of SRL 172 vaccine in patients with advanced stage IV (AJCC) malignant melanoma. Induction of intracellular cytokines (IL-2 and INF-gamma) in peripheral blood lymphocytes (PBLCs) from these patients was assayed and correlated to clinical outcome. PATIENTS AND METHODS: SRL 172 was administered intradermally to 24 patients with stage IV malignant melanoma, initially at 15-day intervals for three vaccinations and then at monthly intervals. Lymphocyte activation for cytokines in PBLCs was assayed prior to each vaccine administration using a FACS-based intracellular cytokine assay. Survival was compared to historical controls. RESULTS: The vaccination schedule resulted in sustained intracellular IL-2 induction in PBLCs in 9 of 23 patients (39%) who received at least three doses. Cytokine induction became apparent within the first three administrations of vaccine and was maximal at 8-12 weeks. Induction of intracellular IL-2 production (group 1) was associated with improved survival (P < 0.036). The median survival of the nine patients demonstrating IL-2 induction was 59 (95% confidence interval (95% CI): 47-71) weeks compared to 31 (95% CI: 18-44) weeks for the non-inducers. Induction of INF-gamma (group 2) was found in 10 patients and 6 patients had IL-2 and INF-gamma induction (group 3). There was no survival advantage for these patient groups. Although no objective responses were documented the group as a whole had a median survival of 44 (95% CI: 31-59) weeks which is better than that of historical controls. SRL 172 was safe and well tolerated. CONCLUSION: SRL 172 is effective in inducing intracellular IL-2 responses in PBLCs of a significant number of patients with stage IV (AJCC) melanoma. This is correlated with improved survival. The survival analysis is sufficiently encouraging to suggest that further prospective trials are justified. The methodology we present in this study may help in developing surrogate markers that will allow rational immunotherapeutic strategies to be designed for cancer patients.

Cancer Vaccines↗

PubMed1999

Prospective clinical evaluation of a programmed atrial stimulation protocol for induction of sustained atrial fibrillation and flutter.

UNLABELLED: We sought to define a minimum standardized protocol for induction of atrial fibrillation [AF] and/or atrial flutter. In contrast to ventricular stimulation protocols, a stimulation protocol for induction of AF or atrial flutter has not been critically evaluated. Since suppression of inducible AF or atrial flutter is used as one of the endpoints of success of pharmacologic and ablation therapies, there is an obvious need to define a minimally appropriate electrical stimulation protocol for induction of AF or atrial flutter. We prospectively evaluated 70 patients, 44 with spontaneous atrial flutter or AF and 26 controls without documented atrial arrhythmias. A standardized programmed stimulation protocol, which employed up to three atrial extrastimuli delivered at two atrial sites at two atrial drive pacing lengths, was used in attempt to reproduce sustained AF and atrial flutter. The study endpoint was induction of sustained (> 30 s) AF or atrial flutter. Sustained AF or atrial flutter was induced in 39/44 (89%) patients and 2/26 (7%) of controls (p < 0.01). The arrhythmia induced was atrial flutter in 19/21 (91%) of atrial flutter patients, AF in 17/18 (94%) AF patients, both atrial flutter and AF in 5 AF/atrial flutter patients (100%). Two patients with atrial flutter had both AF/atrial flutter and 1 patient with AF had atrial flutter induced. The arrhythmia was induced from first stimulation site in 37 patients (85%) using a single extrastimuli in 9 (20%) patients, double extrastimuli 18 (41%) patients and triple extrastimuli in 10 (23%) patients. Two patients (5%) required stimulation from second site with two and three extrastimuli, respectively. The overall sensitivity and specificity of this stimulation protocol were 89% and 92%, respectively with a positive predictive accuracy of 95%. CONCLUSIONS: 1. Up to three atrial extrastimuli and two atrial sites are needed to increase yield of AF/atrial flutter induction at electrophysiologic study. 2. Induction of either AF or atrial flutter correlates well with the presence of a similar spontaneous arrhythmia. 3. A baseline determination of the induction mode may be desirable prior to evaluation of interventions directed at AF or atrial flutter.

Aged↗

PubMed1999

Induction of atrial fibrillation and flutter in dogs using methacholine.

Systemic infusion of methacholine has been used to facilitate induction of atrial fibrillation. However, the dose-response relationship, reproducibility and effect of anesthetic agents on induction are not well understood. The use of methacholine to facilitate electrical induction of sustained (>10 minutes duration) atrial fibrillation or flutter was examined. In 25 dogs induction of atrial arrhythmias was attempted using a series of ten 50 Hz trains of 10 seconds duration delivered via an endocardial catheter in the baseline anaesthetized state and subsequently in the presence of graded doses of intravenous methacholine (maximum 5 microg/kg/min). Studies were repeated in 13 dogs to assess reproducibility. Twelve dogs (48%) had inducible sustained atrial flutter or fibrillation lasting greater than 10 minutes in the baseline state. During infusion of methacholine the remaining 13 (52%) dogs also had inducible sustained atrial flutter or fibrillation (mean infusion rate 1.6 +/- 1.9 microg/kg/min). Induction of sustained atrial flutter or fibrillation was reproducible in all but one dog. The type of anesthetic did not significantly affect inducibility. Induction of prolonged atrial fibrillation or flutter is possible in the baseline anaesthetized state in approximately half of dogs using high frequency programmed electrical stimulation. The yield of inducible sustained atrial fibrillation or flutter with programmed stimulation during intravenous infusion of methacholine was increased to 100%. Induction of sustained atrial fibrillation or flutter was highly reproducible.

Anesthetics, Inhalation↗

PubMed2002

Efficacy of daily induction dosing vs standard thrice weekly dosing of interferon-alpha2B for initial treatment of chronic hepatitis C.

The aim of this study was to compare the effect on HCV RNA levels of using induction dosing with 5 MU interferon-alpha2b (IFN) given daily for four weeks followed by 5 MU IFN given three times a week (TIW) for 44 weeks vs standard noninduction TIW dosing of 5 MU IFN for 48 weeks. We randomly assigned 135 patients with chronic hepatitis C to induction therapy or noninduction therapy. After four weeks of therapy 17/65 (26.1%) patients had undetectable HCV viral levels in the induction group compared with 16/64 (25.0%) patients in the noninduction group. The mean HCV viral levels were similar at four weeks in patients who received induction and noninduction therapy. Mean HCV viral titers in the induction group increased from 4 to 16 weeks, whereas the mean viral titers in the noninduction group decreased during this time (P < 0.0001). HCV RNA was undetectable at the end of therapy in 17/66 (25.8%) in the induction group and 21/68 (30.9%) in the noninduction group. The sustained virologic response rate 24 weeks after the end of therapy was 14/67 (20.9%) in the induction group compared with 13/68 (19.1%) in the noninduction group. These results indicate that an initial four week period of daily interferon confers no benefit in the treatment of patients with chronic hepatitis C.

Adult↗

PubMed2002

[Current aspects of labor induction].

Induction of labor is one of the most important means for therapeutic intervention in modern obstetrics. The aim of labor induction is to achieve a better perinatal result for mother and baby as compared to expectative management. Different methods for induction include administration of oxytocin or prostaglandins, amniotomy, and mechanical means of cervical dilatation. The success of the labor induction depends primarily on the readiness of the uterus to go into labor, and the method used for induction. If the cervical ripeness is very advanced, induction with amniotomy and oxytocin seems beneficial. However if the cervix is not yet ready, intravaginal or intracervical prostaglandins are more promising. Until recently, prostaglandins E2 are used in the first line. Now, the prostaglandin E1-analogon misoprostol is also increasingly used. As a rule, induction of labor should be performed as an inpatient procedure in order to be able to provide the surveillance for maternal and fetal safety.

Critical Pathways↗

PubMed2002

Induction of labor in toxemia with misoprostol.

BACKGROUND: To compare the efficacy and complications of intravaginal misoprostol application with oxytocin infusion for induction of labor in toxemia of pregnancy with a modified Bishop score of < or =4. METHODS: A hundred preeclamptic women with a modified Bishop score of < or =4 were randomized into two groups of 50 patients one group receiving 50 microg intravaginal misoprostol 4 times at 4 hour intervals, the second group receiving oxytocin infusion for induction of labor starting from 1 mIU/per minute, increasing it every 30 minutes with 2 mIU/per minute increments up to maximum of 30 mIU/per minute. Modified Bishop scores 12 hours after induction, the time from induction to delivery, the route of delivery, fetal outcome and maternal complications were recorded. Statistical analyses were performed using Mann Whitney-U, Chi-Square and hypothesis tests about differences for two proportions (t test) to determine differences between the two groups. p< or =0.05 was considered significant. RESULTS: Misoprostol was significantly superior for induction of labor in toxemia of pregnancy with modified Bishop score of < or =4. After 12 hours median modified Bishop scores of misoprostol administered group and oxytocin administered group were 7 and 4 respectively. Misoprostol administered group 1 was significantly better than oxytocin administered group 2 (p=0.027). The rate of patients who were in labor after 12 hours were 94% and 80% in group 1 and 2 respectively and the difference showed significant difference (p<0.05). The median time from induction to delivery was 14 hours and 16 hours in the misoprostol and oxytocin administered group respectively with significant difference between the groups (p=0.003). The rate of vaginal delivery was significantly higher in the misoprostol administered group 1 (82%) when compared with the oxytocin administered group 2 (66%) (p<0.05). The 1 and 5 minutes median Apgar scores were 5-7 and 6-7.5 in group 1 and 2, respectively with no significant differences between the groups (p=0.96, p=0.64). The rate of admission to neonatal intensive care unit was similar in both groups. The complication rates were similar in all groups and no significant detrimental effects were noted. CONCLUSIONS: Intravaginal misoprostol is an efficacious, cheap and safe method of induction of labor in toxemia of pregnancy with modified Bishop score of < or =4.

Administration, Intravaginal↗

PubMed2002

A comparison of two dosage regimens of oral misoprostol for labor induction at term.

METHODS: 251 women with indications for labor induction at term were randomised to receive either 50 or 100 microgs of oral misoprostol, repeated every 4 h to a maximum of 5 doses. Parous women in the higher dose group received 50 microgs as their first dose, subsequent doses being 100 microgs. Women who failed to respond to the 5 doses of misoprostol had the option of having vaginal PGE2 gel. The primary outcome measure was the induction to delivery interval in those who delivered vaginally. Patient satisfaction was assessed by postnatal questionnaire. RESULTS: The induction to vaginal delivery interval, although shorter in the 100 microgs group was not statistically significant (26.8 versus 33.7 h, mean difference 6.9 h, 95% CI 0.4-13). There were, however, more failed inductions with misoprostol in the 50 microgs group (12.7% Vs 4.8%, RR 2.6, 95% CI 1.07-6.5). There were no differences in the modes of delivery, number of caesarean sections for fetal distress or in the neonatal outcomes in the two groups. Most patients, 83% and 92% in the 50 and 100 microgs, respectively, were satisfied with their inductions, and 64% of patients would prefer to have the inducing agent given orally if they were to have another induction. CONCLUSION: Oral misoprostol is effective in inducing labor and seems acceptable to patients. Both the 50 and 100 microgs dose regimens have a reasonable safety profile, but in view of the higher incidence of failed inductions with the 50 microgs dosage, the 100 microgs dose regimen may be the preferred dose regimen.

Administration, Oral↗

PubMed2002

Induction to delivery time interval in patients with and without preeclampsia: a retrospective analysis.

BACKGROUND: Anecdotally, it is suggested that patients with preeclampsia have a shorter induction to delivery interval than patients without preeclampsia, despite there being no good objective evidence. METHODS: A retrospective analysis of 136 primiparous, singleton, cephalic, nonassisted vaginal deliveries between January 1997 and January 2000. Sixty-eight women had induction of labor for preeclampsia and 68 women without preeclampsia had induction of labor for other reasons. The two groups were already case-matched for maternal and gestational age. The following details were recorded from the case notes: maternal age, gestation at delivery, initial Bishop score, total dose of prostaglandin administered, induction to delivery interval, duration of second-stage labor, birthweight, and the percentage of Apgar scores < 7 at 5 min. Statistical analysis was carried out with a Mann-Whitney U-test, with the aid of SPSS version 9, Microsoft Windows RESULTS: The women with preeclampsia had a statistically significant longer induction to delivery interval than those without preeclampsia. The mean induction to delivery interval of women with and without preeclampsia was 1049.5 min and 762.5 min, respectively (p < 0.001) CONCLUSION: Women with preeclampsia had a longer induction to delivery interval than patients without preeclampsia. This fact must be considered when deciding upon the mode of delivery in preeclamptic patients.

Adult↗

PubMed2003

Prospective, randomized, multi-center trial of antibody induction therapy in simultaneous pancreas-kidney transplantation.

A randomized, multicenter, prospective study was conducted at 18 pancreas transplant centers in the United States to determine the role of induction therapy in simultaneous pancreas-kidney (SPK) transplantation. One hundred and 74 recipients were enrolled: 87 recipients each in the induction and noninduction treatment arms. Maintenance immunosuppression consisted of tacrolimus, mycophenolate mofetil, and corticosteroids. There were no statistically significant differences between treatment groups for patient, kidney, and pancreas graft survival at 1-year. The 1-year cumulative incidence of any treated biopsy-confirmed or presumptive rejection episodes (kidney or pancreas) in the induction and noninduction treatment arms was 24.6% and 31.2% (p = 0.28), respectively. The 1-year cumulative incidence of biopsy-confirmed, treated, acute kidney allograft rejection in the induction and noninduction treatment arms was 13.1% and 23.0% (p = 0.08), respectively. Biopsy-confirmed kidney allograft rejection occurred later post-transplant and appeared to be less severe among recipients that received induction therapy. The highest rate of Cytomegalovirus (CMV) viremia/syndrome was observed in the subgroup of recipients who received T-cell depleting antibody induction and received organs from CMV serologically positive donors. Decisions regarding the routine use of induction therapy in SPK transplantation must take into consideration its differential effects on risk of rejection and infection.

Antibodies↗

PubMed1997

Induction of the oxidative catabolism of retinoid acid in MCF-7 cells.

Cytochrome P450-dependent oxidation is a pathway for all-trans-retinoic acid (all-trans-RA) catabolism. Induction of this catabolic pathway was studied in MCF-7 breast cancer cells. MCF-7 cells showed low constitutive all-trans-RA catabolism. Concentration-dependent induction was obtained by preincubation of the cells with all-trans-RA (10(-9) to 10(-6) M). Onset of induction was fast, being detectable within 60 min, with maximal induction (45-fold) obtained after 16 h. Enzymatic characterization of induced all-trans-RA catabolism showed an estimated Km value (Michaelis-Menten constant) of 0.33 microM and a Vmax value (maximal velocity of an enzyme-catalysed reaction) of 54.5 fmol polar all-trans-RA metabolites 10(6) cells(-1) h(-1). These kinetic parameters represent the overall formation of polar metabolites from all-trans-RA. Induction of all-trans-RA catabolism was also obtained with other retinoids, CH55 >> 13-cis-RA = all-trans-RA > 9-cis-RA > 4-keto-all-trans-RA > 4-keto-13-cis-RA > retinol. The potency of the retinoids to induce all-trans-RA catabolism was correlated to their retinoic acid receptor affinity (Crettaz et al, 1990; Repa et al, 1990; Sani et al, 1990). Induction of all-trans-RA catabolism was inhibited by actinomycin D. Furthermore, all-trans-RA did not increase cytosolic retinoic acid-binding protein (CRABP) mRNA levels. These data suggest that induction of all-trans-RA catabolism in MCF-7 cells is a retinoic acid receptor-mediated gene transcriptional event. Induced all-trans-RA catabolism was inhibited by various retinoids with decreasing potency in the order: all-trans-RA > 4-keto-all-trans-RA > 13-cis-RA > 9-cis-RA > 4-keto-13-cis-RA > retinol > CH55. The antitumoral compound liarozole-fumarate inhibited all-trans-RA catabolism with a potency similar to that of all-trans-RA.

Antineoplastic Agents, Hormonal↗

PubMed1999

The ethanol metabolite acetaldehyde inhibits the induction of long-term potentiation in the rat dentate gyrus in vivo.

1. Ethanol has been reported to inhibit the induction of long-term potentiation (LTP) in the hippocampus. However, the correlation between the effects of ethanol in vivo and in vitro remained unclear. In addition, previous works have little considered the possibility that the effect of ethanol is mediated by its metabolites. To solve these problems, we investigated the effects of ethanol and acetaldehyde, the first metabolite in the metabolism of ethanol, on the induction of LTP at medial perforant path-granule cell synapses in the dentate gyrus of anaesthetized rats in vivo. 2. Oral administration of 1 g kg-1 ethanol significantly inhibited the induction of LTP, confirming the effectiveness of ethanol in vivo. 3. A lower dose of ethanol (0.5 g kg-1) failed to inhibit the induction of LTP in intact rats, but significantly inhibited LTP in rats treated with disulfiram, an inhibitor of aldehyde dehydrogenase, demonstrating that LTP is inhibited by acetaldehyde accumulation following ethanol administration. 4. Intravenous injection of acetaldehyde (0.06 g kg-1) significantly inhibited the induction of LTP. 5. The inhibitory effect of acetaldehyde on LTP induction was also observed when it was injected into the cerebroventricules, suggesting that acetaldehyde has a direct effect on the brain. The intracerebroventricular dose of acetaldehyde effective in inhibiting LTP induction (0.1 - 0.15 mg brain-1) was approximately 10 fold lower than that of ethanol (1.0 - 1.5 mg brain-1). 6. It is possible that acetaldehyde is partly responsible for memory impairments induced by ethanol intoxication.

Acetaldehyde↗

PubMed2005

Selective inhibition of inhibitory kappa B kinase-beta abrogates induction of nitric oxide synthase in lipopolysaccharide-stimulated rat aortic smooth muscle cells.

In this study, we utilised a number of adenoviral constructs in order to examine the role of intermediates of the NF-kappaB pathway in the regulation of inducible nitric oxide synthase (iNOS) induction in rat aortic smooth muscle cells (RASMCs). Lipopolysaccharide (LPS) stimulated a significant increase in iNOS induction and NF-kappaB DNA binding. These parameters were substantially reduced by overexpression of a wild-type Ikappa-Balpha adenoviral construct (Ad.Ikappa-Balpha), confirming a role for NF-kappaB in iNOS induction. Infection with a dominant-negative IKKalpha adenoviral construct (Ad.IKKalpha+/-) did not significantly affect iNOS induction, NF-kappaB DNA binding or Ikappa-Balpha loss. Infection of RASMCs with adenovirus encoding a dominant-negative IKKbeta (Ad.IKKbeta+/-) essentially abolished iNOS induction and activation of the NF-kappaB pathway. Pretreatment of RASMCs with a novel specific inhibitor of IKKbeta, SC-514, significantly reduced iNOS induction, NF-kappaB DNA binding and I-kappaBalpha loss in a concentration-dependent manner. In both RASMCs and human umbilical vein endothelial cells (HUVECs), infection with Ad.IKKbeta+/- also inhibited COX-2 expression in response to LPS. However, Ad.IKKalpha+/- was again without effect. These data suggest that IKKbeta plays a predominant, selective role in the regulation of NF-kappaB-dependent induction of iNOS in RASMCs.

Adenoviridae↗

PubMed2001

Transcription factors Oct-1 and NF-YA regulate the p53-independent induction of the GADD45 following DNA damage.

The p53-regulated GADD45 gene is one of the important players in cellular response to DNA damage, and probably involved in the control of cell cycle checkpoint, apoptosis and DNA repair. There are both the p53-dependent and -independent pathways that regulate GADD45 induction. Following ionizing radiation, induction of the GADD45 gene is regulated by p53 through the p53-binding motif located in the third intron of the GADD45 gene. In contrast, GADD45 induction by methyl methanesulfonate (MMS), UV radiation (UV), and medium starvation is independent of p53 status although p53 may contribute to these responses. However, the regulatory elements that control the p53-independent induction of GADD45 remain uncertain. In this report, we have performed detailed analyses to characterize the responsive components that are required for the induction of the GADD45 promoter. We have found that the region between -107 and -62 of the GADD45 promoter is crucial for the induction. Sequence analysis indicates that there are two OCT-1 sites and one CAAT box located in this region. Site-directed mutations of both OCT-1 and CAAT motifs substantially abrogate the induction of the GADD45 promoter by DNA damage. In addition, both Oct-1 protein (binding to OCT-1 site) and NF-YA protein (binding to CAAT box) are induced after cell exposure to DNA damaging agents. Moreover, the Electrophoretic Mobility Shift Assay (EMSA) has demonstrated the direct bindings of Oct-1 and NF-YA proteins to their consensus sequences in the GADD45 promoter. Therefore, these results have presented the novel observation that transcription factors Oct-1 and NF-YA participate in the cellular response to DNA damage and are involved in the regulation of stress-inducible genes.

Base Sequence↗

PubMed2006

Relationship between E1A binding to cellular proteins, c-myc activation and S-phase induction.

We recently showed that p300/CREB-binding protein (CBP) plays an important role in maintaining cells in G0/G1 phase by keeping c-myc in a repressed state. Consistent with this, adenovirus E1A oncoprotein induces c-myc in a p300-dependent manner, and the c-myc induction is linked to S-phase induction. The induction of S phase by E1A is dependent on its binding to and inactivating several host proteins including p300/CBP. To determine whether there is a correlation between the host proteins binding to the N-terminal region of E1A, activation of c-myc and induction of S phase, we assayed the c-myc and S-phase induction in quiescent human cells by infecting them with Ad N-terminal E1A mutants with mutations that specifically affect binding to different chromatin-associated proteins including pRb, p300, p400 and p300/CBP-associated factor (PCAF). We show that the mutants that failed to bind to p300 or pRb were severely defective for c-myc and S-phase induction. The induction of c-myc and S phase was only moderately affected when E1A failed to bind to p400. Furthermore, analysis of the E1A mutants that fail to bind to p300, and both p300 and PCAF suggests that PCAF may also play a role in c-myc repression, and that the two chromatin-associated proteins may repress c-myc independently. In summary, these results suggest that c-myc deregulation by E1A through its interaction with these chromatin-associated proteins is an important step in the E1A-mediated cell cycle deregulation and possibly in cell transformation.

Adenovirus E1A Proteins↗