Genotoxic and biochemical changes in Baccharis trimera induced by coal contamination

The processing and combustion of coal in thermal power plants release anthropogenic chemicals into the environment. Baccharis trimera is a common plant used in folk medicine that grows readily in soils degraded by coal mining activities. This shrub bioaccumulates metals released into the environment, and thus its consumption may be harmful to health. The purpose of this study was to investigate the phytochemical profile, antioxidant capacity (DPPH), genotoxic (comet assay) and mutagenic potential (CBMN-cyt) in V79 cells of B. trimera aqueous extracts in the coal-mining region of Candiota (Bt-AEC), and in Bagé, a city that does not experience the effects of exposure to coal (Bt-AEB, a reference site). In the comet assay, only Bt-AEC was genotoxic at the highest doses (0.8mg/mL and 1.6mg/mL), compared to the control. For extracts from both areas, mutagenic effects were observed at higher concentrations compared to the control. The cell damage parameters were significantly high in both extracts; however, more striking values were observed for Bt-AEC, up to the dose of 0.8mg/mL. In chemical analysis, no variation was observed in the contents of flavonoids and phenolic compounds, neither the antioxidant activity, which may suggest that DNA damage observed in V79 cells was induced by the presence of coal contaminants absorbed by the plant.

[Spanish 'flu in Leipzig 1918-1920]

Town archives enable reconstruction of an outbreak of a flu epidemic and its consequences for Leipzig in 1918 in 1919. First news of the 'Spanish disease' reaching Leipzig appeared in local press on 1st July 1918. The danger was on purpose underestimated not to upset the public and weaken its 'moral resistance'. Eventually because of parents' protests schools were closed at the end of October. The statistics and resources of the archives indicate 1409 persons dying between July 1918 and March 1919. Naturally the youngest and the oldest suffered most fatalities. The disease caused also interference in public life when a theatre and a number of public institutions were closed and public gatherings forbidden.

Prenatal diagnosis and fetal pathology in a Turkish family harboring a novel nonsense mutation in the lysosomal alpha-N-acetyl-neuraminidase (sialidase) gene

We report a Turkish family with parental consanguinity and at risk for sialidosis type II, an inherited autosomal recessive disorder caused by lysosomal alpha-N-acetyl-neuraminidase (sialidase, NEU1) deficiency. The proband was a premature male infant that presented with hydrops, hepatomegaly, respiratory distress syndrome, and anemia and that died of respiratory insufficiency 2 months after birth despite intensive care. An abnormally increased [14C]methylamine incorporation and an isolated deficiency of lysosomal alpha-N-acetyl-neuraminidase were found in cultured skin fibroblasts. A previous pregnancy of the mother terminated in a spontaneous abortion in the 13th week of gestation. A successive pregnancy showed hydrops fetalis, and an enzymatic assay of cultured amniotic fluid cells indicated a deficiency of alpha-N-acetyl-neuraminidase. Following pregnancy termination at 20 weeks gestation, light microscopy of fetal tissues revealed classic vacuolation not only in liver, bone marrow, brain, and kidney, but also in endocrine organs such as the thyroid gland, adrenal gland, hypophysis, and testes, and in the thymus. DNA analysis of the family showed that both the proband and the third sibling had a novel homozygous nonsense point mutation at nucleotide 87 in exon 1 of the alpha-N-acetyl-neuraminidase (neu1) gene causing a substitution of tryptophan at codon 29 by a termination codon (W29X). DNA sequencing of polymerase chain reaction products identified the parents as heterozygous carriers. To detect neu1 mRNA expression, a real-time reverse transcription/polymerase chain reaction was performed, and similar rates of neu1 mRNA expression were found in the fibroblasts of the fetus, the 2nd sibling, and in controls. The very early termination codon with complete loss of neuraminidase activity is probably the molecular basis of the unusually severe vacuolation pattern in this form of congenital sialidosis.

Computer-assisted orthopedic surgery with individual templates and comparison to conventional operation method

STUDY DESIGN

Comparison was made of the accuracy of a pedicle bore performed by conventional technique and by using an individual template in the lumbar spine of cadavers.

OBJECTIVES

The fixation of pedicle screws necessitates a high amount of surgical skill and experience to avoid lesions of nerves and vessels. By using individual templates in a cadaver study the goal was to prove the accuracy and efficiency of this less-invasive image-guided surgery in comparison with the conventional technique by fluoroscopy and computed tomographic (CT) scan.

SUMMARY OF BACKGROUND DATA

Based on three-dimensional models generated from CT scans of the lumbar spine, precise preoperative planning of the position and trajectory of pedicle screws is possible. In comparison with other means of computer-assisted spine surgery with navigation systems, in which a time-consuming intraoperative matching of the bone surface structure is necessary, the use of individual templates enables the surgeon to reduce the operation time considerably.

METHODS

Individual templates are customized on the basis of three-dimensional reconstructions of the bone structures extracted from CT image data and depending on the individual preoperative surgical planning, which uses the desktop image processing system for orthopedic surgery (DISOS). A desktop-computer-controlled milling device is used as a three-dimensional printer to automatically mold the shape of small reference areas of the bone surface into the body of the template. Postoperative CT scans were obtained and the accuracy of the pedicle bore rated by two independent observers.

RESULTS

The preparation time with the individual template lasted slightly longer than with the conventional operation technique (555 seconds and 482 seconds, respectively). Fluoroscopic study took a mean time of 31.5 seconds, with the conventional operation technique and 5.5 seconds with the individual template. The assessment of the postoperative CT scans demonstrated a higher accuracy of the pedicle bore with the individual template.

CONCLUSIONS

This cadaveric study has shown that overall operation time including the fluoroscopy time can be shortened by using the individual template for the pedicle bore. The individual template is an alternative to the computer-assisted navigation systems with a good cost-performance ratio without excessive technical workload on the physicians or the surgical personnel. Further investigations must be conducted to validate the clinical applicability of this system.

[Iatrogenic medication: estimation of its prevalence in French public hospitals. Regional Centers of Pharmacovigilance]

The French network of Regional Centres of Pharmacovigilance has made an estimation of the occurrence of adverse drug reactions in a representative sample of patients in French public hospitals (departments of medicine, of surgery and of geriatrics). The study looked at one specific day in the spring of 1997. Each observed case of adverse drug reaction was validated. The total sample comprised 2132 patients of whom 969 were in a university hospital and 1163 in a general hospital. The hospitals and units concerned are representative of the country as a whole. One adverse drug reaction at least was present for 221 patients on the day of the investigation. This means a prevalence rate of 10.3 per cent (95 per cent CI: 8.7 to 11.9 per cent). In 33 per cent of cases (95 per cent CI: 26 to 42 per cent), the observed effects were rated as serious. From an incidence rate of 1.8 per cent (95 per cent CI: 1.0 to 25 per cent) on one specified day it can be estimated that in France an adverse drug reaction will occur in about 1,300,000 patients per year during a stay in hospital.

[Not Available]

At the beginning of the 20s, Russia was devastated by famine and plagues. This paper deals with the life and work of the Leipzig physician Paul Carly Seyfarth (1890-1950), who participated in the Red Cross relief expedition to Russia. In 1922/23, Seyfarth was appointed director of the German Alexander-Hospital in Petersburg, which he reorganized and modernized for the treatment of infectious diseases.

[Captopril test for detecting renal artery stenosis: changes in plasma renin concentration]

The aim of this study was to demonstrate the diagnostic value of changes in active renin concentration during the captopril test (measurements of plasmatic active renin concentrations, before 12.5 or 37.5 mg of captopril p.o., and 30 and 90 minutes after) in order to screen a significant renal artery stenosis. After a renal angiography, 88 hypertensive patients suspected of renovascular hypertension were classified according to the percentage of stenosis in the main renal artery: class I (< 30% - n = 50), II (30 to < 75% - n = 21), III (75 to < 90% - n = 8) and IV (90 to 100% - n = 11). The results of the captopril test were compared to those of renal angiography. The active renin before the test (basal AR), the greater increase in active renin after captopril (max AR), the difference between max AR and basal AR (DIF) and the active renin relative change after the test (RC) were compared in the 4 classes (ANOVA). There were no differences in diastolic blood pressure (> or = 90 mmHg) natriuresis (100 mmol/24 h in mean) between these different classes. The basal AR, the max AR, the DIF and the RC significantly differed between the 4 classes. They were greater in class III and IV than in class I. The positive criteria for the captopril test were max AR, DIF and RC. The positivity thresholds were max AR > or = 70 ng/l, DIF > or = 50 ng/l and RC > or = 165% (upper limit in the class I 95% confidence interval for each criterion).(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis and ocular antihypertensive activity of new imidazolidine derivatives containing a beta-blocking side chain

The syntheses of new phenylimidazolidine derivatives (3-6)1 containing a propanolamine oxime or an oxypropanolamine moiety attached either to the aromatic or to the imidazolidine ring are described. These compounds were evaluated for potential ocular antihypertensive activity in alpha-chymotrypsin-induced ocular hypertension in rabbits. These compounds represent a unique series of effective ocular antihypertensive agents that despite possessing structural characteristics of beta-blockers and of imidazolidine derivatives, exhibit weak alpha- and beta-adrenergic agonist and antagonist activities. These findings may be of significant therapeutic importance in the medical management of glaucoma.

Effect of tertatolol and of its metabolites and structural analogues in isolated perfused rat kidney vasculature

The renal vascular effect of tertatolol and analogues was investigated in isolated rat kidney perfused at constant flow in an open circuit with Krebs-Henseleit solution after vascular tone had been reestablished by bolus injections of serotonin or other vasoconstrictor drugs. Against serotonin-induced vasoconstriction, (+/-)tertatolol (3 X 10(-7)-3 X 10(-5) M) evoked concentration-dependent relaxation (IC 50 = 4.6 +/- 0.4 X 10(-6) M), (-)tertatolol was more active than the racemic and (+)tertatolol was less active. (+/-)Tertatolol competitively antagonized serotonin-induced renal constriction (pA2 = 5.6 +/- 0.2). Tertatolol metabolites (4-OH tertatolol, 4,5-di-OH tertatolol, and sulfoxy tertatolol) were inactive. (+/-)Sotalol and (+/-)nadolol, were also inactive in this model and (-)bunolol induced renal vasodilatation only at concentrations 40 times higher than (-)tertatolol. The renal response to tertatolol was not linked to release of prostaglandins or dopamine or to interaction with the dopamine receptor, since neither indomethacin nor SCH 23390 affected tertatolol-induced renal vasodilatation. Tertatolol also elicited relaxation of N6-cyclohexyladenosine-induced renal vasoconstriction (34 +/- 7% relaxation at 3 X 10(-5) M) but was inactive when renal vascular tone was raised by prostaglandin F2 alpha, angiotensin II, or neuropeptide Y in the presence of norepinephrine.

New 1,4-dihydropyridine derivatives combining calcium antagonism and alpha-adrenolytic properties

A series of twelve 1,4-dihydropyridine derivatives incorporating an alpha-adrenergic moiety in one of the ester chains was synthesized. The compounds were evaluated for their calcium antagonist activities by the inhibition of [3H]nitrendipine binding and, in vitro, on pig coronary artery. Their alpha 1- and alpha 2-adrenolytic effects were assessed from their inhibition of [3H]prazosin and [3H]yohimbine binding and, in vitro, on rat aorta and guinea pig vas deferens. Compounds 6 and 9-11 displayed strong calcium antagonist activities, identical with that of nicardipine. The moderate alpha-adrenolytic properties observed were attributed to the presence of alpha-adrenergic moieties. The four chiral derivatives 6a (R,R), 6b (S,S), 6c (S,R), and 6d (R,S) with an N-methyl-N-(benzodioxanylmethyl)amino group on the ester chain were prepared and tested as done previously. Some structure-activity relationships are discussed.

Synthesis and pharmacological properties of "soft drug" derivatives related to perhexiline

In the hope of reducing the toxicity of perhexiline, a series of 27 cyclohexylaralkylamines II based on the "soft drug" concept and incorporating an amide function were synthesized. In a preliminary screening, compounds were evaluated for their alpha-adrenolytic activities. Several derivatives, especially N-(cyclohexylphenylmethyl)-2-(cyclohexyl-methylamino)acetamide (3), N-(cyclohexylphenylmethyl)-2-(homoveratrylmethylamino)acetam ide (7), and N-[2-(cyclohexylamino)ethyl]-alpha-cyclohexylbenzeneacetamide (23) had the same activity range as perhexiline in vitro in rat aorta strips. The in vitro metabolism of these three molecules was then investigated and compared to that of perhexiline. The effect upon the alpha-adrenolytic activity of introducing various N-aralkylamine groups on II was examined. Structure/activity relationships are discussed.

Effects on the sodium channel of some new cardiotonic drugs: the 4-, 5-, and 6-pyridyl-2(1H)-quinolone derivatives

To study the action of some new cardiotonic drugs, the 4-, 5-, and 6-pyridyl-2(1H)-quinolone series, on the fast Na+ channel, we compared the effects of eight compounds of this series and milrinone on 22Na uptake in rat brain synaptosomes and in rat heart muscle cells in culture. The action of tetrodotoxin, a specific Na+ channel blocker, on the positive inotropic effect of these compounds on guinea pig atria was also examined. The new positive inotropic agents enhance 22Na uptake in synaptosomes in a dose-dependent manner. The activities, expressed as percentage of the maximum activity of protoveratrine B, a classic Na+ channel agonist, reached 70% for milrinone, 60% for compound 7, 57% for compound 6, and less than 50% for the other drugs. For compound 8, but not for milrinone, it was possible to observe a stimulatory effect of the 22Na uptake on heart muscle cells in culture. Tetrodotoxin (1 and 100 microM) inhibited the stimulatory effects of the inotropic drugs on both preparations. The positive inotropic activities of protoveratrine B, milrinone, and compounds 5 and 8, in guinea pig atria, were inhibited by tetrodotoxin. The affinity and the activity of the other compounds were unchanged in the presence of tetrodotoxin. Our results showed that the stimulation of Na+ influx through the fast Na+ channel might represent a part of the mechanism of action of the inotropic effect of some new cardiotonic drugs.

Soft drug derivatives related to perhexiline. Part II: In vivo studies

A series of cyclohexylaralkylamines derived from perhexiline and synthesized according to the "soft drug" concept were evaluated for haemodynamic effects and myocardial oxygen consumption in vivo. In anaesthetized rabbits, the most active compounds, 2, 5, and 11 decreased arterial blood pressure, to a greater extent dp/dtmax and, to a lesser extent heart rate. The decrease in cardiac work and the decrease in cardiac output varied concomitantly. The cardiac effort index decreased in all cases to a greater degree than with perhexiline. In anaesthetized open-chest dogs, the potential antianginal properties of compounds 2, 5 and 11 were due to a decrease in cardiac work via a decrease in cardiac output and myocardial oxygen consumption. None of these compounds reduced arterial blood pressure. Compounds 2 and 5 decreased myocardial oxygen consumption more than perhexiline. Compound 5 was the most promising molecule of this series both as regards cardiac work and myocardial oxygen consumption, being active at a lower dose than perhexiline and having a long active span. These studies suggest that compounds 2, 5 and 11 might be beneficial to patients with angina pectoris.

Soft drug derivatives related to perhexiline. Part I: In vitro studies

A series of cyclohexylaralkylamines derived from perhexiline was synthesized according to the "soft drug" concept. An amide function was introduced as a labile centre to give non-toxic moieties in vivo after the "soft drugs" had attained their therapeutic aims. Compounds were evaluated for their alpha-adrenolytic, calcium antagonist and vasodilator activities in vitro. Some of them, 2, 3, 7 and 15 on rat aorta had alpha-adrenolytic effects comparable to that of perhexiline. Most of them were about 10 times more active calcium antagonists on depolarized pig coronary artery than perhexiline. All derivatives produced concentration-related coronary dilation in the perfused guinea pig heart. Compound 2 was equipotent to perhexiline. The decrease in coronary resistance might, at least partly, be attributable to the alpha-blocking properties of the molecules. In conclusion, the introduction of an amide function into the perhexiline skeleton does not markedly alter the in vitro pharmacological properties.

Effects of amiloride and its analogues on [3H]batrachotoxinin-A 20-alpha benzoate binding, [3H]tetracaine binding and 22Na influx

The ability of amiloride and its analogues to inhibit [3H]batrachotoxinin-A 20-alpha benzoate [( 3H]BTX-B) and [3H]tetracaine binding to rat synaptosomes and to a rat heart membrane preparation was tested. Their ability to inhibit 22Na influx was determined with rat synaptosomes. 5-N-substituted analogues were generally more potent in inhibiting [3H]BTX-B and [3H]tetracaine binding than compounds substituted on the guanidine group. However, the inhibition was not competitive. Amiloride and some of its analogues were as active or more active in inhibiting [3H]tetracaine binding than they were in inhibiting [3H]BTX-B binding. 22Na influx was inhibited with the same relative potencies as [3H]BTX-B binding and a good correlation was found between the two inhibitions. These results show an effect of amiloride and its analogues on the voltage-sensitive Na+ channels, which could partly explain the inotropic effects of these drugs.

No evidence of vascular dopamine receptors in the rat portal vein

Dopamine (5.3 X 10(-6) to 5.3 X 10(-5) M) decreased the force of spontaneous myogenic contractions of the rat portal vein in a concentration-dependent manner in the presence of the alpha-adrenoreceptor antagonist BE-2254. The DA1-selective agonist fenoldopam and the DA2-preferential agonist (-)-EOE were both inactive. Dopamine-induced relaxation was not inhibited by (+)-butaclamol (10(-8) M), but was reduced by a potent beta 2-selective adrenoreceptor antagonist ICI 118,551 (2 X 10(-8) M). Our results demonstrate that the rat portal vein is devoid of postsynaptic DA1 and DA2 dopamine receptors.

Inhibitory effects of some cyclohexylaralkylamines related to perhexiline on sodium influx, binding of [3H]batrachotoxinin A 20-alpha-benzoate and [3H]nitrendipine and on guinea pig left atria contractions

The antagonist activities of some cyclohexylaralkylamines derived from perhexiline on the fast Na+ channel and slow Ca2+ channel in rat brain and rat heart were examined and compared to the antagonist activities of nifedipine, verapamil, prenylamine and perhexiline. Prenylamine, perhexiline and the cyclohexylaralkylamine derivatives inhibited the [3H]batrachotoxinin A 20-alpha-benzoate binding more than the [3H]nitrendipine binding in rat brain. The nature of the interaction of the cyclohexylaralkylamines with the binding of [3H]batrachotoxinin and [3H]nitrendipine was non-competitive. The synaptosomal 22Na uptake induced by protoveratrine B, a Na+ channel agonist, was also inhibited. Prenylamine, perhexiline and perhexiline derivatives were more potent on the fast Na+ channel than on the Ca2+ channel in contrast to nifedipine and verapamil. The inhibition of Na+ and Ca2+ channels was also shown in guinea pig left atria. Perhexiline, prenylamine and the perhexiline derivatives inhibited the protoveratrine B-induced contraction more than they inhibited that induced by CaCl2, in contrast with nifedipine and verapamil. Our results showed that prenylamine, perhexiline and its related cyclohexylaralkylamines inhibited the fast Na+ channel far more than the slow Ca2+ channel in rat brain, rat heart and guinea pig atria.

A novel positive inotropic series. 2nd communication: in vivo studies of 5- and 6-pyridyl-2(1H)-quinolone derivatives

In the anaesthetized rabbits and dogs, the 6-pyridyl compounds 14, 32 and 33 (0.1-3 mg/kg) and the 5-pyridyl compounds 6 and 7 (1-10 mg/kg), administered i.v., produced dose-related increases in cardiac contractile force lasting more than 30 min. They also produced relatively minor and shorter-lasting increases in heart rate. Only the 6-pyridyl series decreased blood pressure. The effects were not blocked by propranolol. In the normal haemodynamic states, myocardial oxygen consumption did not increase. When the haemodynamic characteristics of heart failure were produced by propranolol in anaesthetized rabbits and dogs, compounds 14, 32 and 33 reversed these effects, increasing in particular cardiac output. These studies suggest that compounds of the 6-pyridyl series might be beneficial in patients with congestive heart failure.

A novel positive inotropic series. 1st communication: in vitro studies of 3-, 4-, 5-, 6-, 7- and 8-pyridyl-2(1H)-quinolone derivatives

A series of 3-, 4-, 5-, 6-, 7- and 8-pyridyl-2(1H)-quinolones and related compounds were evaluated for positive inotropic and vasodilatory activities in vitro. Most of them produced dose-related increases in myocardial contractility on guinea pig isolated atria and perfused heart. In guinea pig atria, the 6-pyridyl molecules were more active than the 5-pyridyl ones; the mean ED50 of compounds 14, 32 and 33 was 4.0 x 10(-7) mol/l i.e. 33 times that of sulmazole; that of compounds 6 and 7 was 2.0 x 10(-5) mol/l. The potencies of the 5- and the 6-pyridyl series also differed by 2 log units on perfused guinea pig heart. The 5- and 6-pyridyl series induced relaxation in precontracted pig coronary artery and coronary vasodilation on perfused guinea pig heart. Compounds 14, 32 and 33 also showed alpha-adrenolytic properties, which were by 0.7 log unit lower than that of phentolamine. These results indicate that this novel cardiotonic series exert positive inotropic and coronary vasodilatory effects.

Effects of various antianginal drugs on sodium influx in rat brain synaptosomes and in rat heart muscle cells in culture

This paper describes the inhibitory effects of several antianginal drugs on 22Na uptake of the fast Na+ channel in rat brain synaptosomes and in rat heart muscle cells in culture. Calcium antagonists like verapamil, flunarizine, perhexiline, two perhexiline derivatives IPS 629 and IPS 672, and beta-adrenoceptor antagonists like propranolol and practolol were tested. IPS 672 was the most active compound on synaptosomes and heart muscle cells (IC50 = 2.0 X 10(-6) and 2.4 X 10(-6) M respectively). The relative potencies of the Ca2+ antagonists tested on heart muscle cells were found to be IPS 672 greater than IPS 629 greater than perhexiline greater than flunarizine greater than verapamil. Verapamil was 55 and 10 times less active than IPS 672 on synaptosomes and heart cells respectively. Propranolol had an inhibitory activity comparable to that of flunarizine and was 100 times more active than practolol. It can be concluded that several antianginal drugs seems to interfere with the Na+ fast channel on rat brain and heart.

Cardiotonic agents. 1. Synthesis and structure-activity relationships in a new class of 3-, 4-, and 5-pyridyl-2(1H)-quinolone derivatives

A series of 3-, 4-, and 5-pyridyl-2(1H)-quinolone derivatives with H or HO or CH3O substituents in the 8-position were prepared and tested for positive inotropic activity. Several derivatives, especially 29, 9b, and 27 with a pyridyl ring in the 5-position, were ca. 2-10 times more potent on left guinea pig atria than sulmazole (ARL-115) and milrinone used as references. Some structure-activity relationships are discussed.

Cardiotonic agents. 2. Synthesis and structure-activity relationships in a new class of 6-, 7-, and 8-pyridyl-2(1H)-quinolone derivatives

A series of 6-, 7-, and 8-pyridyl-2(1H)-quinolone derivatives with various quinolone substitutents (CH3, Cl, OH, OCH3) was prepared by arylation of pyridine with quinolone via a diazotized aminoquinolone for positive inotropic activity. Several derivatives, especially those with a pyridyl ring in the 6-position, were from 28 to 50 times more potent on left guinea pig atria than ARL-115 and milrinone used as references. Intrinsic activities of the derivatives were almost equivalent to that of ARL-115. These results indicate that pyridyl-2(1H)-quinolone derivatives are a potent new class of positive inotropic agents.

Effect of some new cardiotonic agents on synaptosomal sodium uptake

The new positive inotropic agents sulmazole, piroximone, milrinone and 1,5-dihydro-6-chloro-3-methy-limidazo [2,1-b]quinazolone-2 enhance 22Na uptake in rat brain synaptosomes. In comparison, theophylline, a cyclic nucleotide phosphodiesterase inhibitor, has no effect on synaptosomal 22Na uptake. Tetrodotoxin inhibits the stimulation induced by the new inotropic agents. The quinazolone is about three times more potent than protoveratrine B and milrinone and ten times more potent than sulmazole and piroximone. There is a direct correlation between the 22Na uptake and the positive inotropic effect on guinea pig left atria of the new cardioactive drugs. The dose-response curves for synaptosomal 22Na uptake and for the inotropic effect on guinea pig left atria are parallel for sulmazole and the quinazolone drug, with first an increase and then a decrease in activity.

Inhibition of some new cardiotonic agents by tetrodotoxin

The effects of sulmazole, milrinone and 1,5-dihydro-6-chloro-3-methylimidazo[2,1-b]quinazolone-2 on guinea pig left atria were studied, measuring the force of contraction in the absence and in the presence of 1 x 10(-5) mol/l octahydro-12-(hydroxymethyl)-2-imino-5,9: 7,10a-dimethano-10aH-[1,3]-dioxocino[6,5-d]pyrimidine- 4,7,10, 11,12-pentol (tetrodotoxin, TTX). The dihydropyridine derivative methyl 1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-tri-fluoromethylphenyl) pyridine-5-carboxylate, a Ca2+ agonist, was also tested. Protoveratrine B, which prolongs the Na+ current phase, was inhibited by TTX. Isoprenaline, whose activity is mediated by cyclic adenosine monophosphate and consequently by the increase in slow inward Ca2+ current, was not. TTX antagonized competitively sulmazole, milrinone and the quinazolone drug and reduced only the activity of the dihydropyridine derivative. These results suggest an interference of the new cardiotonic drugs with the fast Na+ channel.

The manipulative patient

"Manipulative" is a popular but often misused description of behavior seen in some patients who come to psychiatric attention. The authors suggest a definition of "manipulation" which can impart helpful information about symptoms, diagnosis, and treatment. They survey the differential diagnosis of manipulative behavior and consider specific treatment strategies.

Coronary vasodilation and positive inotropic effect of non steroidal cardiotonics

The effects of several cardiotonic agents (ARL-115, Amrinone, RMI 82-249, Milrinone, CI-914, RO 13-6438 and APP 201-533) were compared with those of ouabain on pig isolated coronary artery, guinea-pig isolated atria and guinea-pig perfused heart to compare vasodilatory and inotropic responses. Like ouabain, all compounds tested produce positive inotropic and chronotropic effects in isolated atria and on perfused heart, and induce relaxation in precontracted pig coronary artery and coronary vasodilation on perfused heart, except ouabain which induces vasoconstriction. The results indicate that non steroidal cardiotonics exert positive inotropic and coronary vasodilatory effects.

Postjunctional alpha-1 and alpha-2 adrenoceptors in the coronaries of the perfused guinea-pig heart

Prazosin and yohimbine were used to differentiate postjunctional alpha adrenoceptors in the coronaries of the perfused guinea-pig heart. Two postjunctional alpha adrenoceptor subtypes were distinguished by the affinities of the receptor for yohimbine and prazosin. The pA2 for yohimbine were 8.74 against alpha-methylnorepinephrine and 8.98 against BHT-920, and the pA2 for prazosin was 9.84 against phenylephrine. Yohimbine was not very active against the alpha-1 selective agonist as was prazosin against the alpha-2 selective agonists. Alpha-1 and alpha-2 postjunctional adrenoceptors mediate vasoconstriction in the whole coronary bed of the perfused guinea-pig heart.

Synthesis and beta-adrenergic blocking activity of new aliphatic and alicyclic oxime ethers

We describe the synthesis and pharmacological properties of two new series of aliphatic and alicyclic beta-adrenergic blockers, most of them containing a cyclopropyl ring. They belong either to 2-hydroxy-3-(tert-butylamino)propyl ether A or 2-hydroxy-3-tert-(butylamino)propyl ketoxime ether B derivatives. The O-[2-hydroxy-3-(tert-butylamino)propyl] dicyclopropyl ketoxime 5 exhibited a beta-adrenergic antagonist activity comparable to that of propranolol. It was found that ketoxime ethers B generally showed higher potency than the corresponding ethers A. We confirm that the presence of an aromatic nucleus is not crucial for the beta-adrenergic activity. Structure-activity relationships among these series are discussed.

Postjunctional alpha-adrenoceptors. Alpha 1 and alpha 2 subtypes in rat vasculature in vitro and in vivo

The postsynaptic alpha-adrenoceptors in rat aorta and in pithed rat were investigated according to their sensitivity to nine alpha-adrenergic agonists and to the selective antagonists yohimbine (alpha 2) and prazosin (alpha 1) and the nonselective one, phentolamine. In addition, in radioligand binding studies, the affinity and selectivity of the drugs were determined on rat cerebral cortex using [3H] yohimbine and [3H] prazosin. On rat aorta, prazosin is 1,000 times more potent than yohimbine against each alpha-adrenoceptor agonist, whether alpha 1- or alpha 2-selective. Rat aorta probably contains only alpha 1-adrenoceptors. Pressor effects in pithed rats are mediated by post-junctional alpha 1- and alpha 2-adrenoceptors. The dose-response curve for alpha-methylnorepinephrine in the presence of prazosin, using Hofstee's plots, revealed alpha 1- and alpha 2-adrenoceptors, respective proportions being 80.5 and 19.5%.

Effects of theophylline and isoproterenol on the activity on the isolated guinea pig ureter

To determine the role of the autonomic nervous system and of cyclic AMP in the control of ureteral peristalsis, isolated guinea pig ureters were placed in a 20-ml organ bath containing modified Krebs solution. Theophylline induced significant dose-dependent reduction in frequency and amplitude of contractions of the ureter hypertonified with barium chloride. No change in frequency or amplitude of contractions was observed with isoproterenol. Besides, our data explain why beta-agonist drugs are of very little value in the treatment of renal colic due to spasms of the pelviureteral tract.

[Cardiovascular effects of urapidil]

The cardiovascular effects of urapidil have been investigated in the anesthetized rat. The mechanism of the hypotensive action of this drug has been tested in vitro on the isolated rat aorta and in vivo by intracerebroventricular injections. The peripheral vasoconstrictor effect has been studied in the pithed rat. In the pithed rat, the thoracic part of the spinal cord was electrically stimulated in order to induce a tachycardia. The reduction of this tachycardia by a drug is due to its inhibitory effect on cardiac sympathetic nerves endings. Intravenous urapidil produces a significant hypotension without change in heart rate. Directly injected into the brain cavities, urapidil produces a hypotensive effect only at very high doses (1 mg/kg). This hypotensive action of urapidil appears therefore to be mainly of peripheral origin. Urapidil antagonizes competitively the contraction of the aorta induced by norepinephrine. The drug has alpha-blocking properties which explain its hypotensive action. On the other hand, urapidil provokes a weak vasoconstrictor effect in the pithed rat and induces a presynaptic inhibition in the heart which may explain the lack of heart rate change during the hypotensive effect of the drug. Urapidil may therefore also stimulate post or presynaptic alpha 2-adrenoceptors.

Study of two alkylating derivatives: the p-isothiocyanato- and the p-methylisothiocyanato-clonidine

Pharmacological experiments with isolated rat aorta and radioligand binding studies in rat cerebral membranes were performed with the p-isothiocyanato (p-NCS) and p-methylisothiocyanato (p-CH2-NCS) derivatives of clonidine in order to assess their selectivity for alpha 1- and alpha 2-adrenoceptors, and to characterize their ability to alkylate alpha-adrenoceptors. Preincubation of rat aortic strips with both derivatives produced non-parallel rightward shifts in the dose-response curves of noradrenaline and significantly depressed the maximum response in a manner characteristic of irreversible receptor antagonists. The p-CH2-NCS derivative was slightly more potent than the p-NCS derivative. Further analysis of the data indicated that treatment of rat aorta with a 30 microM concentration of the p-CH2-NCS derivative alkylated all but 2.4 percent of the alpha-adrenoceptors, whereas a 100 microM concentration of the p-NCS derivative was required to produce a similar degree of alpha-adrenoceptor alkylation. Radioligand binding studies indicate an apparent 2 fold alpha2-adrenoceptor selectivity for the p-NCS derivative. In contrast, the p-CH2-NCS derivative displayed 7 fold selectivity for alpha 1-adrenoceptors. Interestingly, both alkylating derivatives of clonidine produced dose-dependent contractile responses in rat aorta with pD2 values of 6.30 and 5.56 for the p-NCS and p-CH2-NCS derivatives, respectively, relative to a pD2 of 7.67 for clonidine. The order of potency of the two alkylating derivatives of clonidine for producing contraction of rat aorta is the opposite of that for antagonizing the contractile effects of noradrenaline. The results suggest that the p-NCS and p-CH2-NCS derivatives of clonidine non-competitively antagonize noradrenaline by irreversibly alkylating alpha-adrenoceptors.

Synthesis and cardiovascular activity of a new series of cyclohexylaralkylamine derivatives related to perhexiline

A series of 24 cyclohexylaralkylamine derivatives related to perhexiline has been synthesized and screened for cardiovascular activity. All the compounds contained an exocyclic amine which was substituted either by an alkyl, cycloalkyl, or aralkyl group. In the hope of further reducing toxicity, the synthesis of p-tolyl- and p-hydroxyphenyl derivatives 23 and 24 was undertaken. The effect of separating the cyclohexylamine moiety with respect to the aromatic nucleus has been systematically examined. The pharmacological investigations were directed to a search for compounds having an activity better than perhexiline according to the following order of criteria: (1) alpha-adrenolytic activity; (2) increase of coronary blood flow; (3) calcium antagonism. Several compounds were more potent and exhibited lower toxicity than perhexiline. Further detailed pharmacological investigations (tension time index and decreased cardiac work) have led to the selection of N,2-dicyclohexyl-2-phenethylamine (3) for clinical trials, which are now under way.

Effects of N-aralkyl substitution of beta-agonists on alpha- and beta-adrenoceptor subtypes: pharmacological studies and binding assays

The pharmacological and binding properties of four beta-adrenomimetic drugs with N-alkyl substitutions (isoprenaline, terbutaline, salbutamol and soterenol) were compared with those of four corresponding drugs with N-aralkyl substitutions (protokylol, ME 506, salmefamol and zinterol). BD-40 A, a very powerful beta 2-agonist with a related chemical structure, was also included in this study. The beta 1- and beta 2-activities of these drugs were determined on guinea-pig atria and trachea, their alpha-adrenolytic activity was measured on rat aorta and their affinities (Ki) for alpha 1- and alpha 2-adrenoceptors on rat cortical membranes were assessed using [3H]prazosin and [3H]yohimbine. In this group of beta-agonists, substitution of the N-alkyl by an N-aralkyl group had a variable effect on the beta 2-selectivity whereas alpha-adrenolytic properties were always enhanced. An increase of the affinities (Ki) for both alpha 1- and alpha 2-adrenoceptors was found but the effect was much more pronounced for alpha 1-adrenoceptors. These results indicated that the alpha-adrenolytic activity observed with the N-aralkyl beta-agonists was selective for alpha 1-adrenoceptors.