Timing of pain and bleeding after mifepristone-induced abortion

Previous studies of medical abortion with mifepristone and a prostaglandin have reported percentages of subjects who experience cramping and/or bleeding relative to prostaglandin use. This is the first analysis of cramping and bleeding onset patterns in subjects treated with low-dose (200 mg) mifepristone and 800 microg vaginal misoprostol at 24, 48, or 72 h after mifepristone. We analyzed the cramping and bleeding onset patterns in subjects up to 8 weeks pregnant who used 800 microg vaginal misoprostol at 24, 48, or 72 h after 200 mg of oral mifepristone. We collected data from subjects' symptom diaries and divided symptom onset into 3 categories: before misoprostol use, 0--12 h following misoprostol, and more than 12 h after misoprostol. Of the 2,302 subjects, cramping and bleeding onset data were available for 2,030 (88%) and 2,123 (92%), respectively. Across all groups, 230 (11%) experienced cramping and 445 (21%) experienced bleeding before misoprostol use. There was a significantly higher percentage of subjects who experienced early cramping and/or early bleeding between the three treatment groups, and this was related to the interval between mifepristone and misoprostol. In the 12 h following misoprostol administration, cramping and bleeding patterns were similar in the three groups. The longer subjects waited to insert misoprostol, the more likely they were to experience early cramping and/or bleeding. After misoprostol insertion, cramping and bleeding patterns are similar regardless of treatment group. Patients and providers cannot rely on symptom onset to predict treatment success.

Impact of nasal ventilation on survival in hypercapnic Duchenne muscular dystrophy

BACKGROUND

Respiratory failure is the commonest cause of death in patients with Duchenne muscular dystrophy (DMD). Life expectancy is less than one year once diurnal hypercapnia develops. This study examines the effects of nasal intermittent positive pressure ventilation (NIPPV) on survival in symptomatic Duchenne patients with established ventilatory failure.

METHODS

Nocturnal NIPPV was applied in 23 consecutive patients with DMD of mean (SD) age 20.3 (3.4) years who presented with diurnal and nocturnal hypercapnia.

RESULTS

One year and five year survival rates were 85% (95% CI 69 to 100) and 73% (95% CI 53 to 94), respectively. Early changes in arterial blood gas tensions following NIPPV occurred with mean (SD) PO2 increasing from 7.6 (2.1) kPa to 10.8 (1.3) kPa and mean (SD) PCO2 falling from 10.3 (4.5) kPa to 6.1 (1.0) kPa. Improvements in arterial blood gas tensions were maintained over five years. Health perception and social aspects of SF-36 health related quality of life index were reported as equivalent to other groups with nonprogressive disorders using NIPPV.

CONCLUSIONS

Nasal ventilation is likely to increase survival in hypercapnic patients with Duchenne muscular dystrophy and should be considered as a treatment option when ventilatory failure develops.

A comparison of the cytology of endomyocardial biopsy washings from heart transplants with biopsy histologic study and peripheral blood lymphocyte counts

Cytospin preparations of endomyocardial biopsy washings were examined on 117 occasions from 13 heart transplant recipients and categorized according to the pattern of cell types observed. Twenty-nine percent of samples were acellular, a further 10% too bloodstained for analysis, and 61% were cellular. Eight lymphocytic samples were found and in all cases there was at least grade 1B rejection (four grade 1B, three grade 2, and one grade 3A) on histologic study. However, histologic study showed at least 1B rejection in 48% of cases when cytospins showed mixed inflammatory cells, 33% of cases when cytospins were histiocytic and in 35% when cytospins were bloodstained or acellular. Furthermore 16 of these rejection episodes with nonlymphocytic cytospins were grade 2. Although the recovery of a lymphocytic cytospin was specific for rejection, the sensitivity of the test was poor. Even when the sample is adequate, this method of biopsy washings will predict only one third of cases of significant acute rejection (grade 2 or worse). The large proportion of unsuitable samples also severely limits the utility of endomyocardial biopsy washings for the diagnosis of rejection. Histiocytic cytospins were seen in 63% of samples when previous biopsy sites were reported on histologic study and also in all three samples when histologic study showed ischemic injury. A mixed inflammatory cell pattern was seen to a lesser extent (31% of samples) in relation to previous biopsy sites. High peripheral blood lymphocyte counts were found when endomyocardial biopsy washings were lymphocytic or mixed inflammatory and also when histologic study showed endocardial lymphocytic infiltration (Quilty effect).

Bone marrow and serum connective tissue polypeptides in idiopathic myelofibrosis

The distribution of collagen type VI and tenascin has been determined in both normal and myelofibrotic bone marrow by immunohistological techniques. In normal sections positivity was demonstrated in the periosteum (collagen type VI and tenascin) and in the walls of small blood vessels (tenascin). In contrast, myelofibrotic bone marrow showed an increased deposition of both proteins, especially collagen type VI, although this increase was restricted to the later fibrotic stages of the disease. Serum concentrations of collagen type I (PICP), collagen type III (PIIIP) and laminin (laminin P1) related polypeptides were determined in a further 26 patients. PIIIP levels were significantly raised, in contrast to PICP and laminin P1 concentrations. All three markers, however, were significantly elevated in patients with active/transforming disease. Laminin P1 and PICP levels showed a strong correlation, indicating a relationship between basement membrane and interstitial collagen metabolism, although they do not appear to offer any advantage over PIIIP for the monitoring of disease activity.

Enhancement of salt intake by choline chloride

The ingestion of salt (NaCl) in most societies far exceeds levels that are considered necessary and safe. To reduce salt intake, a rat model of salt taste acceptance was created to identify novel, more palatable salt substitutes/enhancers. To induce salt craving, male Sprague-Dawley rats were placed on a low-salt diet and injected weekly (SC) with either 100 mg/kg of deoxycorticosterone acetate (DOCA) or its vehicle, peanut oil. Following 16 h of fluid deprivation, intake was evaluated in a one-bottle acceptance procedure. The DOCA-injected animals consumed large volumes of salt-containing solutions (up to 120 ml in 2 h) and showed sensitivity to and specificity for the salt taste (generally lacking acceptance of dextrose, KCl, ammonium chloride, and water solutions). Using this model, choline chloride was identified as having salt taste-enhancing properties. Choline chloride (0.1-0.7%) significantly enhanced the intake of a dilute salt solution (0.1%). The relevance of the rat model was demonstrated in human taste trials; choline chloride enhanced the palatability of and preference for foods containing this compound. The results of the present experiments support the use of this animal model for evaluating compounds for salt-like taste qualities and suggest that choline chloride will be an effective salt taste enhancer in man.

Cardiotonic and coronary vasodilator responses to milrinone, forskolin, and analog P87-7692 in the anesthetized dog

Forskolin and milrinone both increase cyclic AMP concentrations to enhance cardiac contractility and cause vascular dilation in vitro and in vivo. However, forskolin acts via direct stimulation of adenylate cyclase while milrinone inhibits phosphodiesterase (PDE-III) activity. The forskolin analog, 7-desacetyl-7-(O-propionyl)-hydroxyl-aminocarbonyl-forskolin (P87-7692) has also been shown to directly stimulate adenylate cylase and increase cyclic AMP production in isolated cardiac tissue; however, the in vivo activity of this compound has not been described. Thus, the purpose of this study was to compare the cardiovascular effects of equivalent doses of these compounds and to further characterize the cardiotonic activity of P87-7692 in the anesthetized dog. It was found that both i.v. (3-30 micrograms/kg) and intracoronary (0.1-30 micrograms) administration of milrinone, forskolin, and P87-7692 caused dose-related positive inotropic, coronary, and peripheral vasodilator effects in anesthetized dogs; however, P87-7692 produced significantly greater and more sustained cardiotonic activity following a single 30-micrograms/kg, i.v., bolus injection when compared to the same dose of milrinone and forskolin. Analysis of the dose-response relationship between the changes in contractile force and heart rate for these compounds revealed that a 50% augmentation in contractile force was associated with increases in heart rate of 2.1% for milrinone, 6.4% for P87-7692, and 13.7% for forskolin. These data indicate an improved separation between the chronotropic and inotropic effects for P87-7692 as compared to forskolin. All three compounds also produced coronary vasodilation in vivo and in vitro; however, P87-7692 consistently showed greater activity relative to the same doses of milrinone and forskolin. Moreover, P87-7692 was significantly (p less than 0.05) more potent at relaxing KC1-precontracted canine coronary rings, with an EC50 of 2.1 x 10(-7) M as compared to 1.1 x 10(-6) M for forskolin and 3.2 x 10(-6) M for milrinone. The results of these studies indicate that structural modification of the forskolin molecule can increase the separation between positive inotropic and chronotropic effects, improve the overall hemodynamic profile, and prolong the duration of cardiotonic activity for this class of compounds.

GABAmimetic agents display anxiolytic-like effects in the social interaction and elevated plus maze procedures

Benzodiazepine (BZD) anxiolytics, through their activation of the BZD-GABA receptor complex, display robust anxiolytic-like effects following systemic administration in both conditioned and non-conditioned behavioral procedures. The present results show that the GABAA agonists muscimol (0.5-1.0 mg/kg), THIP (2.5-10.0 mg/kg), and isoguvacine (25.0 mg/kg) as well as the GABA transaminase (GABA-T) inhibitor AOAA (aminooxyacetic acid; 5.0-20.0 mg/kg) following intraperitoneal administration exert anxiolytic-like activity of similar magnitude to that of diazepam in two non-conditioned procedures, namely the social interaction and the elevated plus maze tests. We have also extended our original findings that the anti-epileptic drug sodium valproate exerts an anxiolytic-like effect in the Geller conflict paradigm, to show this agent's robust activity in the social interaction and elevated plus maze tests following systemic administration (100-400 mg/kg). These results show that GABAergic agents that facilitate GABA transmission are effective following systemic administration in non-conditioned anxiety procedures and may indicate potential therapeutic efficacy in certain anxiety states.

Effects of 5-HT1A receptor agonists and NMDA receptor antagonists in the social interaction test and the elevated plus maze

The effects of several 5-HT1A agonists and excitatory amino acid antagonists were compared to the standard benzodiazepines, diazepam and chlordiazepoxide (CDP) in two assays predictive of anxiolytic activity, the social interaction and elevated plus maze procedures. Indicative of anxiolytic effects the 5-HT1A agonists, buspirone, gepirone and 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) all significantly increased social interaction time and open arm exploration time in the social interaction and elevated plus maze procedures, respectively. Likewise, anxiolytic activity in these assays were also produced by the competitive N-methyl-D-aspartate (NMDA) antagonists, 2-amino-5-phosphonovaleric acid (AP-5), 2-amino-7-phosphonoheptanoic acid (AP-7), 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) and the non-competitive NMDA antagonist, (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801) while NMDA produced anxiogenic effects. Furthermore, the anxiolytic effects of these agents were of equal magnitude to the benzodiazepines. These two classes of compounds were differentiated in the yohimbine-induced seizure assay, with the NMDA antagonists dose dependently antagonizing seizures similar to the benzodiazepines while the 5-HT1A agonists were inactive. These results suggest that the 5-HT1A agonists and the NMDA antagonists may be potential non-classical anxiolytic agents with different mechanisms of action.

Studies on the ability of smoke from different types of cigarettes to induce DNA single-strand breaks in cultured human cells

In this paper we report preliminary studies using alkaline elution to examine the incidence of DNA-strand breakage in human lung cells exposed to smoke/phosphate-buffered saline generated from cigarettes of different tar contents and filter status. The majority of the DNA breaks induced were abolished by catalase indicating a role for active oxygen species. The incidence of breaks did not correlate with the tar content of the cigarettes. The presence of a filter in the cigarette reduced the TPM concentration of the mainstream smoke but did not reduce the number of single-strand breaks occurring in DNA after exposure to smoke/PBS. This last parameter was however reduced if the filter was ventilated.

Characterization of the discriminative stimulus effects of physostigmine in the rat

Rats were trained to discriminate physostigmine (0.1 mg/kg s.c.) from saline in a two-choice, discrete-trial avoidance paradigm. Stimulus generalization curves for physostigmine were steep; complete generalization with physostigmine occurred only at the 0.1 mg/kg training dose. The muscarinic cholinergic agonists oxotremorine, pilocarpine and arecoline were evaluated for physostigmine-like discriminative effects. Oxotremorine generalized with physostigmine at a dose of 0.1 mg/kg in four of six rats tested; partial generalization was engendered by this dose in the remaining two animals. Complete generalization with physostigmine was produced in only one of six rats treated with pilocarpine. However, pilocarpine (3.0-10 mg/kg) did engender some physostigmine-appropriate responding in all rats tested. Arecoline (1.0 mg/kg) produced primarily saline-appropriate responding in all animals tested. Neostigmine, eseroline and nicotine were tested for physostigmine-like discriminative effects in order to assess the specificity of the physostigmine cue. Eseroline (1.0 mg/kg), an opioid-like derivative of physostigmine, and neostigmine (0.1 mg/kg) engendered saline-appropriate responding. Similarly, nicotine failed to generalize with physostigmine at doses up to 1.0 mg/kg. The discriminative stimulus effects of physostigmine were sensitive to antagonism by atropine. Complete blockade of the stimulus effects of the training dose of physostigmine was produced by 1.0 to 3.0 mg/kg of atropine. In contrast, a 10-fold higher dose of the quaternary antagonist homatropine methylbromide was necessary to block the discriminative effects of physostigmine. The discriminative effects of physostigmine were not blocked or were only partially blocked by mecamylamine at doses up to 10 mg/kg. The results of these experiments suggest that the discriminative stimulus effects of physostigmine are selective and probably centrally mediated.(ABSTRACT TRUNCATED AT 250 WORDS)

Mu-opioid component of the ethylketocyclazocine (EKC) discriminative stimulus in the rat

The opioid receptor selectivity of the EKC discriminative stimulus was characterized in Fischer rats trained to discriminate 0.3 mg/kg EKC (SC) from saline in a two-choice discrete-trial avoidance paradigm. The putative kappa-opioid receptor agonists EKC and U50,488H completely generalized with the EKC cue at doses of 0.3 and 10 mg/kg, respectively. The putative mu-opioid receptor agonists morphine (M) and fentanyl also dose-dependently generalized with the EKC stimulus. The generalization of M with EKC was not symmetrical, EKC and U50,488H produced little or no M-appropriate responding in rats trained to discriminate 3.0 mg/kg M (SC) from saline. This generalization pattern may reflect a lack of opioid receptor selectivity of the EKC stimulus. However, distinct mu-opioid and kappa-opioid components of the EKC cue could be identified using graded doses of naloxone in EKC-trained rats. The discriminative effects of morphine and fentanyl were blocked completely by doses of 0.1-1.0 mg/kg naloxone, whereas doses of naloxone 3-10 times greater were necessary to block the discriminative effects of EKC and U50,488H. These results suggest that EKC produces a complex discriminative stimulus with mu-opioid and kappa-opioid components that can be separated using antagonists such as naloxone.

Initial experience with Tc-99m-HM-PAO in the study of brain tumors

A preliminary study of the distribution of the 99mTc complex of hexamethylpropylene amine oxime (HM-PAO) in 12 patients with brain neoplasms before, during, and after radiotherapy has been performed. Untreated brain tumors were found to exhibit a range of 99mTc-HM-PAO uptake, varying from areas of markedly increased isotope activity to photopenic areas, when compared to normal brain tissue. A ratio of 99mTc-HM-PAO tumor uptake to contralateral normal tissue uptake was calculated prior to and during radiotherapy. This ratio tended to return towards unity in lesions responding to therapy. A predictable alteration in whole brain 99mTc-HM-PAO uptake during radiotherapy was not demonstrated. Unlike the radiolabeled amines, 99mTc-HM-PAO localizes in primary tumors, probably indicating that its uptake mechanism is independent of non specific amine receptors. 99mTc-HM-PAO may be useful in the study of brain tumor physiology and response to therapy.

The biodistribution and pharmacokinetics of meta-iodobenzylguanidine in childhood neuroblastoma

MIBG is generating considerable interest for the treatment of neuroblastoma. This study has investigated the biological variation in handling of the compound in children with neuroblastoma. The biodistribution of the compound has been characterised in children undergoing tracer administrations of 123I and 131I-mIBG. Estimates of hepatic and whole body radiation dose delivery have been made. The results indicate substantial interpatient variation in hepatic dose delivery. This organ may be critical in some patients undergoing targeted radiotherapy with mIBG.

The response to DNA damage induced by 4-nitroquinoline-1-oxide or its 3-methyl derivative in xeroderma pigmentosum fibroblasts belonging to different complementation groups: evidence for different epistasis groups involved in the repair of large adducts in human DNA

The data in this paper show that when the inhibition of growth is measured, xeroderma pigmentosum (XP) complementation groups A, G and D are very sensitive to 4-nitroquinoline-1-oxide (4NQO), whereas only XP groups G and D are very sensitive to 3-methyl-4NQO (3me4NQO). Cells belonging to XP-C group are not particularly sensitive to either agent. Thus there are different epistasis groups for the excision repair of DNA adducts induced by these agents as opposed to the repair of u.v. damage. DNA polymerase alpha is involved in the repair of 4NQO-induced lesions because aphidicolin blocks their repair. XP cells from all the above groups are defective to some extent in this repair. The degree of repair defectiveness follows that seen after u.v., with even the XP-C cell line used having reduced repair (despite the fact that the inhibition of growth by 4NQO in this cell line was not markedly different from normal). Aphidicolin did not induce breaks in the normal or XP cell lines exposed to 3me4NQO, thus the repair of lesions induced by 3me4NQO does not involve DNA polymerase alpha in any of the cell lines. Finally, catalase reduces the alkaline labile lesions induced by 4NQO, but not 3me4NQO, suggesting the latter agent does not induce substantial amounts of DNA damage by the generation of radicals.

Pharmacology of nomifensine: a review of animal studies

Nomifensine has demonstrated efficacy in several animal models that have been found to be predictive of clinical antidepressant activity, and has also been found to have a low potential for both cardiovascular and anticholinergic side effects. A comparison of nomifensine's profile with those of standard antidepressant agents shows this drug to possess clear advantages which may make it an attractive choice for the treatment of endogenous depression.

Comparison of the actions of trimethadione and chlordiazepoxide in animal models of anxiety and benzodiazepine receptor binding

Trimethadione was compared with chlordiazepoxide for anti-anxiety activity in two behavioral tests known to predict the anxiolytic action of drugs. In the drug-discrimination test, male hooded rats were trained to discriminate the anxiogenic action of pentylenetetrazol from saline by responding for food reinforcement on one of two levers after treatment with pentylenetetrazol (1450 mumol/kg) and on the other lever after injection of saline. Pretreatment with either chlordiazepoxide (2.8-33 mumol kg) or trimethadione (559-2236 mumol/kg) prior to the injection of pentylenetetrazol, produced a dose-dependent antagonism of the anxiogenic stimulus. In the other test, male Wistar rats were trained to respond for milk reinforcement in a conflict procedure in which some of the reinforced responses resulted in the delivery of footshock. Treatment of these rats with chlordiazepoxide (17-67 mumol/kg) or trimethadione (1118-2236 mumol/kg) antagonized the footshock-induced suppression of responding. In a receptor binding study, trimethadione failed to inhibit flunitrazepam binding. These data suggest that trimethadione is an effective anxiolytic agent whose action does not directly involve benzodiazepine receptors.

Antinociceptive activity of clonidine and its potentiation of morphine analgesia

The activity of clonidine and its interaction with morphine was assessed in the mouse tail flick assay. In this assay, clonidine was found to be 10 times more potent than morphine. Clonidine potentiated morphine antinociceptive activity approximately five-fold and morphine potentiated clonidine activity four-fold. Clonidine's agonstic activity was not reversed by naloxone hydrochloride (10 mg/kg) while the potentiating effect of clonidine by morphine was. Tolerance to the antinociceptive effect of morphine was observed in morphine pellet-implanted mice but no cross tolerance was observed for clonidine. These data indicate that clonidine-induced analgesia is not a result of an interaction at morphine receptors; but rather, common pathway(s) are present which appear to complement the agonistic interaction of each.