Involuntary movements caused by phenytoin intoxication in epileptic patients.

The case histories of four patients who developed choreoathetoid movements during intoxication with phenytoin are presented. Drug intoxication was confirmed in each case by measuring the serum phenytoin concentration. Drug interactions were, in part, responsible for the occurrence of intoxication in three of them. Phenytoin intoxication is not always easy to recognize, particularly when nystagmus is minimal or absent, as in these four patients. The estimation of the serum phenytoin concentration is invaluable in this situation.


Haemorrhagic and perivenous encephalitis: a clinical-pathological review of 38 cases.

Clinical and pathological data from eight cases of acute haemorrhagic leucoencephalitis (AHL) confirm the previously documented devastating features of this disease. Data from 30 cases of perivenous encephalitis (PVE) associated with viral diseases reveal pathological changes ranging from lymphocytic cuffing of vessels to severe vasculitis similar to the vasculitis of AHL. Relatively few cases show demyelination as a prominent feature. The pathological changes are unrelated to the type of underlying disease with the exception that the pathology of 'post-rubella' encephalitis tends to be mild. Two cases of rubeola and two of mumps showed viral nodules in the cortex, raising the possibility of direct viral invasion of tissue. Allowing for species differences, these changes are analogous to the pathological features of experimental allergic encephalitis (EAE); with the various pathological changes of PVE paralleling the features of ordinary EAE, while the changes of AHL and the severe cases of PVE strongly resemble hyperacute EAE.


Intestinal absorption of cytidine diphosphate choline and its changes in the digestive tract.

Intestinal absorption of cytidine diphosphate choline (CDP-choline), its structural changes in the digestive tract, and hepatic uptake have been investigated in rats using 14C-labeled (14CH3 attached to N of choline) and 3H-labeled (at C5 of pyrimidine) compounds. The results indicate that: 1)CDP-choline is relatively stable in the stomach, but is quickly degraded into cytidine and choline in the intestine; 2) The hepatic uptakes of 14C and 3H reach the maximum in two to three hours after oral administration; 3) Whereas the amount of 14C remaining in the gut is inversely related to the hepatic uptake, no similar correlation is seen with 3H-labeled CDP-choline, and 4) Extrahepatic uptake of 14C and 3H is very small. The possibility of phosphorylation in the mucosa of choline and cytidine has been discussed, based on the differences in individual broken-down products in the intestinal lumen and mucosa.


Purification and properties of the dihydrofolate synthetase from pea seedlings.

Dihydrofolate synthetase [EC 6.3.2.12] was extracted from the cell particles (mitochondrial fraction) of pea seedlings and purified about 2,000-fold by ammonium sulfate fraction, DEAE-cellulose column chromatography, Sephades G-200 gel filtration, and hydroxylapatite column chromatography. The enzyme preparation obtained was confirmed ultracentrifugally to be in the homogeneous state. The sedimentation coefficient of this enzyme was calculated as 3.9S. The apparent molecular weight of the enzyme was determined to be about 56,000. Optimum pH for the reaction was 8.8. The enzymatic reaction required dihydropteroate, L-glutamate and ATP as substrates, and divalent (Mg2+ or Mn 2+) and univalent K+, NH4+ OR Rb+) cations as cofactors. The enzyme was specific for dihydropteroic acid as the substrate. ATP was not replaceable with any other nucleotides. Km values for dihydropteroate, L-glutamate, ATP, Mg2+, and Mn2+ were 1.0 X 10 MINUS 6, 1.5 X 10 MINUS 3, 1.0 X 10 MINUS 4, 1.1 X 10 MINUS 3 AND 6.3 X 10 MINUS 5 M, respectively. The enzymatic reaction was inhibited by the addition of ADP, but not by AMP. This suggests that the product fromATPin the reaction is composed of ADP PLUS Pi. Thus, it is proposed that this enzyme catalyzed the following reaction: (see article).


Purification and properties of thiamine pyrophosphokinase from parsely leaf.

Thiamine pyrophosphokinase was purified about 8,000-fold from extracts of parsely leaves. The enzyme, as prepared, was homogenous on polyacrylamide gel electrophoresis. The molecular weight of the enzyme, estimated by gel filtration with Sephadex G-150, was approximately 30,000. In 0.05 M Tris-HCl, the enzymic activity showed a pH optimum over a range of 8 to 9. A least squares analyses of Lineweaver-Burk and Hofstee plots gave Km values of 0.8mM and 0.15mum for ATP and thiamine, respectively. Thiamine homologues and analogues so far tested, except for cetyl thiamine, were all inactive as substrates. The enzyme was specific for ATP and Mg++, although to a lesser extent a combination with other ribonucleoside triphosphates or divalent cations could replace them. SH reagents, such as PCMB, NEM and iodoacetamide, were potent inhibitors of the enzyme. The inhibition was prevented by the addition of dithiothreitol. Inorganic pyrophosphate exhibited striking inhibition. TMP could not replace thiamine as the substrate, whereas it inhibited the TPP formation from thiamine. These findings are consistent with the views that TMP is not directly converted to TPP but after being dephosphorylated by the action of a monoesterase, thiamine is pyrophosphorylated with ATP by thiamine pyrophosphokinase (EC 2.7.6.2) to form TPP and thus give a clear evidence regarding the mechanism of TPP formation in plant tissues.


Renal tubular acidosis and skeletal demineralization in patients on long-term anticonvulsant therapy.

Three children ranging from seven to 12 years of age from unrelated families were given long-term anticonvulsant therapy including acetazolamide (Diamox). These children had rickets and renal tubular acidosis. Investigations have suggested (1) secondary hyperparathyroidism due to hypocalcemia of rickets and (2) prolonged acetazolamide therapy were responsible for acidosis as a result of reduction of bicarbonate reabsorption in the kidney. A clear-cut recovery from acidosis and rickets was seen in two patients following medication with high doses of vitamin D, an oral supplement of phosphorus, and discontinuance of acetazolamide therapy.


Immediate effects of alkaline infusion in infants with respiratory distress syndrome.

Nineteen infants with acidosis associated with RDS were studied following the infusion of: (1) 0.58M (7%) THAM over 30 seconds; (2) molar bicarbonate over 30 seconds; (3) molar bicarbonate over 2 minutes; and (4) molar bicarbonate over 5 minutes. PaC02 fell after THAM; PaC02 rose sharply after bicarbonate and remained elevated 10 minutes after infusion. The pH rose abruptly in all infants and remained significantly elevated 10 minutes after infusion. Pa02 changes were variable; no infant had immediate improvement in Pa02. The changes in osmolality, hematocrit, and colloid osmotic pressure describe the immediate osmotic hemodilution following the infusion of hypertonic base.


The determination of thebaine in Papaver bracteatum Lindl by gas-liquid chromatography.

Several solvents have been examined in the process of developing a convenient method for extracting powdered material and removing interfering pigments to produce an extract of Papaver bracteatum suitable for g.l.c. assay. The most suitable extracting solvent was aqueous acetic acid (5%); the assay method gave satisfactory reproducibility with a wide range of plant materials (coefficient of variation 0.63 to 3.33%). The accuracy was checked by recovery experiments with pure thebaine and by examination of exhausted marcs. The presence of other alkaloids did not interfer with the assay. There were substantial differences in the amounts of thebaine extracted from capsule and root samples by ammoniacal methanol and by aqueous acetic acid, indicating the presence of thebaine in a "bound" form. The minimum amount of thebaine that could readily be determined by the g.l.c. method was 0.3 mg in the sample of powder used for the assay.


Comparison of the nuclear magnetic resonance and infrared spectroscopic methods for the quantitative analysis of polydimethylsiloxane.

A method based on nuclear magnetic resonance spectroscopy is described for the quantitative determination of polyimethylsiloxane (PMS) in a variety of pharmaceutical preparations. An extraction procedure using deuterochloroform within the sample tube was devised. In the presence of an internal standard, the PMS concentration was determined directly using integrated peak areas, without the necessity of establishing calibration curves. Accurate quantitative results were achieved with sample, containing at least 2mg PMS, extracted from formulations containing greater than 0.5% PMS. The extraction procedure and nmr assay were both more efficient and convenient than the B.P.C. method.


A model for steroid transport across biological membranes.

The absorption of a range of steroids (water soluble to lipid soluble) in the mouth was investigated under standard conditions and using gas chromatography. A two-compartment open model was used to describe the absorption of these steroids into, and through, the membrane. Rate constants were calculated on this basis using a feathering technique, and were used in an analogue computer program to predict steroid concentration which agree favourably with experimental data. Correlations between absorption and partition data were made in an attempt to relate the proposed model to anatomical features of the absorptive membrane and to make comparison with models proposed to describe drug absorption across the intestinal mucosa.


Factors influencing the excretion and relative physiological availability of pethidine in man.

Factors influencing the urinary excretion of pethidine, norpethidine and pethidine N-oxide have been examined. The proportion of a dose of pethidine excreted unchanged or as norpethidine depends on the urinary pH and the route of administration. Older people appear to metabolize more of the drug and therefore excrete less unchanged pethidine. The rate of excretion of pethidine in acid urine is directly proportional to the plasma pethidine concentration and under these conditions the relative physiological availability of pethidine has been determined. It has not been possible to explain variations in the amount of pethidine excreted as the N-oxide.


The role of dopamine and noradrenaline in temperature control of normal and reserpine-pretreated mice.

Drugs with the common property of stimulating dopamine receptors, have been tested for their effects on core temperature in control and reserpine-pretreated mice. Apomorphine, amantadine, amphetamine, L-dopa and atropine all produced a fall in mouse oesophageal temperature, their efficacy correlating with their ability to activate central dopamine receptors. Amphetamine and L-dopa had a biphasic effect the initial fall being followed by a rise. In reserpine-pretreated mice only amphetamine, apomorphine, L-dopa and D.L-threo-dihydroxyphenyl-serine effectively reversed hypothermia. Amphetamine had the highest efficacy of all the drugs tested. The sum of the effects of apomorphine and D.L-threo-dihydroxyphenylserine was equivalent to the effect of amphetamine alone. It is suggested that in control mice dopaminergic mechanisms mediate the hypothermia and noradrenergic mechanisms the hyperthermia. In reserpine-pretreated mice both systems are involved in the mechanisms restoring body temperature to normal.


Investigation of changes in the lipid content of guinea-pig lung after anaphylaxis.

A detailed analysis of the lipid content of guinea-pig lung following anaphylaxis in vivo induced by aerosolized antigen showed a significant reduction in all fractions. Anoxia induced by nitrogen produced reductions in the partial glycerides and ethanolamine phospholipid. Exposure to an aerosol of histamine caused a reduction in all but the choline phospholipid and sphingolipid fractions. It was concluded that the losses of choline phospholipid and sphingolipid result from the anaphylactic reaction and not from subsequent changes.


Release of adrenaline by anaphylaxis in the guinea-pig: its effect on lung lipid content.

The study was undertaken to discover whether the catecholamines released as a result of the stress and hypoxia of anaphylaxis were responsible for the concomitant loss of lipid from the lung. A method is described whereby the respiratory rate and volume and heart-rate of conscious sensitized guinea-pig were measured and the electrocardiogram recorded during anaphylaxis induced by aerosolized antigen. After 7 days or more, some animals were anaesthetized with pentobarbitone and respiration was artificially maintained at the level recorded in the conscious state, whilst the quantity of catecholamines liberated during anaphylaxis was assayed using an extra-corporeal blood circulation to superfuse smooth muscle preparations. In other animals of the same group, it was shown that intravenous infusion of adrenaline in a similar quantity to that detected in the circulation following anaphylaxis (0.3 mug min-(-1) for 40 min) caused losses of triglyceride and partial glycerides from the lungs. Thus, the loss of choline-containing phospholipid was attributed to the direct effects of the anaphylactic reaction on the lung tissue.


The effect of acute bilateral adrenalectomy on vasopressor responses to catecholamines in dogs.

The effect of acute bilateral adrenalectomy on the pressor responses to adrenaline, noradrenaline and isoprenaline was studied in anaesthetized dogs. The responses to all the three catecholamines were reduced by adrenalectomy. Treatment with cortisone, cyclic AMP partially restored the responsiveness. Desocycorticosterone, aldosterone, hydrocortisone, phenylbutazone or infusion of either saline and noradrenaline failed to improve the impaired pressor responses seen in adrenalectomized dogs. Treatment with corticosterone alone. combined administration of aldosterone and hydrocortisone or cortisone followed by cyclic 3',5'-AMP also restored catecholamine responses amost to normal. The pressor responses to catecholmaines in dogs were also reduced by metyrapone-induced cortical insufficiency. Administration of corticosterone, cortisone or cyclic AMP slightly improved these responses; the recovery was not, however, as effective as that noted in the adrenalectomized condition.


An anomalous effect of the intermediate products of riboflavine photolysis on the intestinal absorption of poorly absorbed water-solbule drug in rats.

The influence of the intermediate products of riboflavine photolysis on the absorption of poorly absorbed water-soluble drugs from the rat small intestine has been examined using an in situ recirculation technique. The absorption of phenol red, bromphenol blue (BPB) and their biliary excretion, and lactose isonicotinoyl-hydrazone (lactose-INH) and its plasma concentration were increased in experiments made in the presence of light in contrast to other made in the dark. The absorption of both phenol red and lactose-INH were concentration-dependent. On the other hand, a saturation phenomenon was demonstrated when the concentration of phenol red was kept constant while that of the water-soluble compound flavine mononucleotide (FMN) was changed. The results which were obtained from pretreatment experiments suggest an alteration in the permeability of the intestinal membrane. No enhancement effect could be demonstrated for lumichrome in the presence of absence of light.


Pharmacokinetics of haloalkylamines: cyclization and distribution in blood in vitro and in vivo.

The cyclization of N-(5-chloropentyl)-N-methylaminoaceto-2,6-xylidide hydrochloride (RAD 150) and N-(5-bromopentyl)-N-methylamino-aceto-2,6-xylide hydrobromide (RAD 154) in red blood cells of rats and rabbits was examined under in vitro and in vivo conditions. The rate of cyclization was much slower in plasma and blood than in a buffer solution, probably due to influence of protein binding of the compounds. The tertiary amines disappeared rapidly from the blood cells in vitro and in vivo and the piperidinium derivative (RAD 179) formed from the haloalkylamines disappeared almost as rapidly as the tertiary amines from the plasma in vivo. In contrast, the efflux of RAD 179 formed in the blood cells was slow (T 1/2 for rabbit erythrocytes: 9 h in vitro; 8 h in vivo) following a 1st order reaction. RAD 179 itself was only to a small extent taken up in the blood cells.


Skin irritants of Euphorbia fortissima.

By means of a combination of partition and chromatographic methods six irritant constituents were isolated from the fresh latex of Euphorbia fortissima. Compounds A-D were di-esters of the common parent diterpene 12-deoxyphorbol, and compounds E and F were mono-esters of the same diterpene. The fresh latex had an irritant dose 50% (ID50) on mice of 0-64 mug mul- minus 1. Compounds A-D are short-acting irritants reaching a maximum activity within 4 h of application to the skin, whilst the monoesters maintained potent irritant effects for up to 24 h. Selective hydrolysis of the di-esters at the C-20 primary ester group also produced mono-esters of greater potency after 24 h. An increase in the length of the fatty acid located at C-13 produced greater biological activity in both the mono- and di-ester groups.


Metabolism of phenothiazines: identification of N-oxygenated products by gas chromatography and mass spectrometry.

The solid inlet mass spectra of the N-oxide and N-oxide sulphoxide metabolites of promazine, chlorpromazine and methotrimeprazine have been determined at different temperatures and compared with the mass spectra of the main thermolytic product of the N-oxides and N-oxide sulphoxides obtained during combined gas chromatography-mass spectrometry. Diagnostic ions were produced by direct insertion of the compounds at ambient temperature into the mass spectrometer. These ions distinguish the N-oxides of arylalkyl tertiary amines from the N-oxygenated derivatives of primary and secondary arylalkylamines.


Metabolism of quinalbarbitone.

The human metabolism of (+/-)-5-allyl-5-(1'-methylbutyl) barbituric acid (I), quinalbarbitone, taken orally, has been studied. Comparison of g.c. and g.c.-m.s. data from derivatized extracts of urine with similar data from synthetic samples confirmed the presence of the two diastereoisomeric forms of 5-allyl-5-(3'hydroxy-1'-methylbutyl)barbituric acid (II), 5-allyl-5-(3'-oxo-1'-methylbutyl)barbituric acid (III), 5-allyl-5-(1'-methyl-3'-carboxypropyl)barbituric acid (IV), and 5-(2',3'-dihydroxypropyl)-5-(1'-methylbutyl)barbituric acid (V) in the urine. There was no evidence for the urinary excretion of unchanged drug. The rate of excretion of these metabolites has been examined in some detail, and rate-limited kinetics shown to apply for excretion of the acid (IV) and the diol (V).


The diffusion of penicillin G and ampicillin through phospholipid sols.

The self-diffusion coefficients of penicillin G and ampicillin have been determined at 25 degrees in water and in the presence of a swamping concentration of electrolyte. The antibiotics diffused through phospholipid dispersions at a reduced rate due to interaction with the lipid aggregates. Ampicillin diffused through the phosphatidylcholine and phosphatidylethanolamine dispersions more rapidly than penicillin G, whereas the latter diffused more rapidly through the lysophosphatidylcholine dispersions. Estimates of binding have been made from these data and compared with those obtained from equilibrium dialysis studies. Surface tension measurements indicated that the antibiotics exhibited minimal surface activity. These results have been correlated with data obtained in other studies and a possible explanation has been advanced for the reported differences in vivo activity of penicillin G and ampicillin.


The instrumentation of a Zanasi LZ/64 capsule filling machine.

The dosator system of a Zanasi LZ/64 capsule filling machine was modified and strain gauges were fitted. These were used to measure the forces on the powder being filled during compaction and ejection. The patterns of those forces produced were shown to differ between different materials and between lubricated and unlubricated materials. Tentative reasons for the observed differences have been suggested.


The development of a radioimmunoassay for cannabinoids in blood and urine.

Antibodies, for use in radioimmunoassay, have been raised in sheep by immunization with a conjugate of delta9-tetrahydrocannabinol hemisuccinate and bovine serum albumin. Antiserum titre and avidity were increased by successive booster doses of conjugate. The high degree of non-specific binding encountered in the radioimmunoassay of cannabinoids was reduced by the use of the solubilizing detergent Triton X-405 and by restricting protein concentration in the assay medium. Plasma samples were deproteinized with ethanol before assay, but urine was directly assayed. High avidity antibodies and high specific activity [3H]-delta9-tetrahydrocannabinol permitted the detection of 50 pg of cross-reacting cannabinoids--a sensitivity of 7-5 ng ml-1 of plasma and 1-0 ng ml-1 of urine. Whilst apparently specific for the three-ringed cannabinoid nucleus, the assay antiserum cross-reacted with several cannabinoids, both natural compounds and metabolites. Partial identification of cross-reacting cannabinoids was achieved by the use of pure compounds and by the assay of plasma and urine samples collected from rabbits given pure cannabinoids intravenously.


Prostaglandins and the anti-inflammatory activities of aspirin and sodium salicylate.

Acetylsalicylic acid (aspirin) and sodium salicylate are equally effective in reducing the swelling in the carrageenan-induced paw test and the accumulation of leucocytes into the inflammatory exudate produced by the subcutaneous implantation of polyvinyl sponges in the rat. Aspirin but not sodium salicylate caused a significant reduction in the potentiation of paw oedema found after the concurrent administration of carrageenan and arachidonic acid. Some implications of these findings are discussed.


The surface activity of the alveolar lining layer of guinea-pig lung following anaphylaxis.

The surface activity and lipid composition of alveolar extracts of guinea-pig lung following anaphylaxis have been studied. The extracts showed a reduced ability to lower surface tension on compression of the surface film which was maximal 30 min after challenge. No significant changes in the lipid content were found but there was a marked increase in the soluble solids 10 min after anaphylactic shock. The significance of these findings is discussed.


Effects of thioridazine and diazepam on the pharmacokinetics of [14C]imipramine in rat: acute study.

The pharmacokinetics of [14C]imipramine (10 mg kg minus 1) were tested in male Wistar rats for interaction with thioridazine (16 mg kg minus 1) or diazepam (10 mg kg- minus 1). All drugs were administered orally with the test substances being given 40 min before [14C]imipramine dosing. Bile and urine were collected for 90 min after the radioactive drug was given. The animals were then killed and the tissues removed. Thioridazine reduced the excretion of radioactivity into the bile and urine, and increased the weight of the contents within the gastrointestinal tract. These effects were interpreted as being mainly due to a reduction in gastrointestinal motility resulting in a slower stomach emptying of [14C]imipramine. No effect on metabolism was detected. Diazepam pretreatment reduced the concentration ratio of radioactivity in the small intestinal contents to that of plasma, but did not alter the tissue distribution, metabolism or excretion of [14C]imipramine.


Characterization of an angiotensin II-fluorescamine derivative.

The coupling of fluorescamine (4-phenylspiro[furan-2(3H), 1'-PHTHALAN]-3,3'dione) to angiotensin II to form a fluorescent derivative was studied. Complete reaction of the peptide below concentrations of 10- minus 4 M could be achieved with a fluorescamine concentration of 0-3 mg ml- minus 1 of acetone at pH 8-3, and the lowest concentration detectable by fluorescence spectroscopy was 100 pmol ml- minus 1. The derivative, as prepared did not react with ninhydrin, and no fluorescence was generated when fluorescamine was reacted with (1-Sar)-ATII. These data suggest that fluorescence is generated only through the coupling of fluorescamine to the N-terminal primary amine of ATII. The ATII-fluorescamine derivative has the same intrinsic activity on the contraction of rat colon (elevenfold loss of affinity), and on the release of fluorogenic corticosteroids from bovine adrenal cortical slices (sixfold loss of affinity) compared to ATII. Water-hydrolysed fluorescamine and Asp-fluorescamine did not contract rat colon preparations; the contractile response to ATII-fluorescamine was blocked by (8-Leu)-ATII, a specific ATII antagonist. These findings suggest that theATII fluorophore shares a common receptor site with the native octapeptide. The rate loss of biological activity of the ATII-fluorescamine derivative was appreciably lower than that observed for ATII. The present study suggests that the ATII-fluorescamine derivative can be substituted for radioactively-labelled ATII for use in a variety of applications.


Synthesis and characteristics of the enantiomers of the cyclic metabonate of methadone.

2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (II), a cyclic metabonate of methadone was synthesized from methadone (I) and methadone-N-oxide (III). M-Chloroperbenzoic acid was used to oxidatively demethylate I while sulphur dioxide reductively demethylated III to give II. The importance of these syntheses lies in the fact that there is no attack on the asymmetric carbon atom in I or III, thus providing direct methods of obtaining the optical isomers of II.


The interaction of aminoalkylaminoanthraquinones with deoxyribonucleic acid.

A series of aminoalkylaminoanthraquinones have been prepared as potential intercalating agents. The binding to DNA of these compounds and the known intercalating drugs chloroquine, lucanthone, daunorubicin and doxorubicin has been characterized by spectrophotometric titration. The association constant for the interaction with DNA has been determined for each compound from a Scatchard plot. The compounds synthesized had association constants between 0-5 and 4-2 times 10(6) compared with 0-93, 0-90, 3-10 and 2-49 times 10(6) for chloroquine, lucanthone, daunorubicin and doxorubicin respectively.


The effect of mucin on the bioavailability of tetracycline from the gastrointestinal tract; in vivo, in vitro correlations.

The bioavailability of tetracycline in the presence and absence of a porcine gastric mucin dispersion (1% W/V) has been studied by in vivo perfusion of the rat small intestine, the rat everted gut, a diffusion cell technique and the Sartorius Absorption Simulator Apparatus. In the presence of the mucin preparation an approximate 50% reduction in the numerical values of each of the parameters used to measure the tetracycline movement across the membrane was found. The physiological significance of each technique and the methods themselves are discussed. Interaction of tetracycline with the porcine gastric mucin preparation is considered in relation to the molecular structure of mucus. The results suggest the drug is bound in some way, as yet undefined, to the mucin macromolecule.


A comparison of solute migration in a test granulation dried by fluidization and other methods.

The intragranular migration of sodium chloride in granules made by the wet massing of heavy kaolin B.P. with salt solution has been studied in batches dried by fluidization and a vacuum tumbling method. The larger granules from the fluidized batch exhibited considerable intragranular variation with the outer crust containing over twice the average salt concentration. Solute loss from this layer by abrasion on prolonged fluidization was slight but the dust eluted from the dryer had a salt content above average. Analysis of sieved fractions of the dust showed that this enrichment was concentrated in the fine material passing a 53 mum mesh. The vacuum dried granules had less migration and were less resistant to crushing than those dried by fluidization. The dust produced had a salt content only slightly greater than the average composition and the overall solute content of the sized fractions were all close to this average. The same system was used to study intergranular migration in a fixed bed when the granules were dried by infrared radiation, by microwave radiation, by convection from air and in a vacuum. The greatest migration occurred in samples dried by infrared radiation and the maximum solute concentration was near the middle of the bed. The air dried granules had less migration and the maximum concentration was in the surface layer. The granules dried in a vacuum and by microwave radiation were fairly uniform in composition throughout the bed. The above results are explained on the basis of the capillary theory of drying together with the modifying influence of the drying method on the probable heat and mass transfer rates.


Dopamine receptor blockade and the neuroleptics, a crystallographic study.

The X-ray structures of 12 drugs of the tricyclic class having varying pharmacological profiles have been examined in detail in an attempt to rationalize the known structure-activity relations of neuroleptic drugs with respect to their ability to block dopamine receptors in the brain. Further evidence is presented in support of the theory that the neuroleptics are able to block dopamine receptors because of a conformational complementarity between certain portions of these drugs and dopamine.


The evidence of the release of prostaglandin-like material from rabbit kidney and guinea-pig lung by (minus)-trans-delta9-tetrahydrocannabinol.

Injection of (minus)-trans-delta9-tetrahydrocannabinol (THC) through the renal artery caused a decrease in perfusion pressure and an increase in urine produced by the isolated perfused rabbit kidney. Both effects of THC are inhibited by the prior addition of aspirin to the perfusion medium. THC also induced a dose-dependent increase in perfusion pressure on the isolated perfused lung of guinea-pig and the effluent from the lung produced a contraction on the isolated continuously superfused rat stomach fundus strip. These effects are prevented by the pretreatment of the lung with aspirin which inhibits the production of prostaglandins (PG) and SC 19220 which inhibits the pharmacological effects of PG.


An improved implantation pellet for rapid induction of morphine dependence in mice.

A new type of morphine implantation pellet for the rapid induction of physical dependence in mice can be prepared by absorbing 7 mg morphine sulphate onto molecular sieves Type 4A (BDH). The small cylindrical pellets can be implanted subcutaneously without trauma and the need for anaesthesia, and are easily removed at any time from the animals. The peak of physical dependence is reached 24 h after implantation, and mortality is negligible. Withdrawal symptoms can be precipitated by intraperitoneal injection of naloxone, without removal of the pellet, and up to 70% of a group of mice show the characteristic urge to jump off a raised platform. This type of pellet has definite advantages over some other sustained-release preparations used in studies on morphine addiction in small animals.


The vascular changes after ephedrine tachyphylaxis.

The changes elicited after ephedrine tachyphylaxis in the dog femoral and rabbit aortic strips isolated from the untreated and ephedrine pre-treated animals have been studied. In untreated strips, ephedrine exhibited dose-dependent contractions which were blocked by phenoxybenzamine. These contractile responses to ephedrine were reduced after pre-treatment with ephedrine in vivo. In rabbit aortic strips previously contracted with noradrenaline or KCL, ephedrine induced dose-dependent relaxations at high concentrations, which were not affected by propranolol. These relaxation responses were likewise diminished after ephedrine. Dose-related contractile responses to noradrenaline were potentiated at low concentrations and depressed at high concentrations after ephedrine whereas those to adrenaline were inhibited over the entire agonist range. Responses to KCL were not affected. These reductions in the responses to noradrenaline and adrenaline after treatment with ephedrine in vivo were inhibited by icreased calcium2+ concentration. From the results, it can be presumed that the observed changes in vascular responsiveness may be partially involved in the development of ephedrine tachyphylaxis.


Chemical reactions involved in penicillin allergy: kinetics and mechanism of penicillin aminolysis.

In view of the fundamental importance of the reaction of penicillins with amino groups of proteins to the penicillin allergy, the aminolysis of benzylpenicillin by various amines was kinetically investigated. The formation rate constants, kamide, of benzylpenicilloylamides were determined at 35 degrees, 45 degrees and 60 degrees (mu equals 0.5), and found to obey the general rate law: kamide equals k1[amine] + k2[amine H+] [amine] + k3[amine]2 + k4[amine]aoh. All of the amines exhibited the unassisted nucleophilic rate constant, k1. The relative importance of the other kinetic terms depends on the basicity and the chemical structure of amines. The reaction mechanism of penicillin aminolysis was discussed. Bronsted relations for k1, k2 and k3, except for hydrazines, were satisfactory.


Trialkylsily moieties as potential pharmacokinetic modifying groups for aminoalchohols.

Water soluble derivatives of the aminoalcohols methylephedrine, ephedrine and norephedrine have been synthesized to contain various trialkyl silyl groups attached to the hydroxyl group of the aminoalcohol hydrochloride. Variation of the alkyl substituents on the silyl group produces a wide variety of derivatives possessing differing lipid solubilities and rates of hydrolysis to the parent aminoalcohol.


Dissolution and bioavailability of the anhydrate and trihydrate forms of ampicillin.

The solubilities and intrinsic dissolution rates of ampicillin anhydrate and trihydrate in distilled water and dilute hydrochloric acid at 37 degrees have been measured. The dissolution rates of these materials from loose filled hard gelatin capsules were determined and the in vivo bioavailabilities of the compounds compared. Small differences in the in vitro behaviour of the anhydrate and trihydrate forms were recorded but the in vivo availability of the two compounds was the same.


The percutaneous absorption of phenolic compounds: the effect of vehicles on the penetration of phenol.

The effects of interactions between drug and skin, drug and vehicle, and vehicle and skin on the overall penetration rate of a drug through the skin may be evaluated by comparison of penetration rates through excised skin and an inert reference membrane such as polyethylene. Dimethyl sulphoxide, dimethyl formamide, ethanol and water increase the permeability of the skin but because of reduced thermodynamic activities in the vehicles low penetration rates are observed.


Development and evaluation of a dexamethasone timed-release aerosol formulation.

Dexamethasone microcapcules were prepared and in vitro parameters were determined by sieve analysis which yielded materials retained on Nos. 80-, 100-, 200-, and 270-mesh sieves. Release rate and direct total determinations indicated that some measure of timed release appeared in all four sieve samples. The pH-release rate profiles of the microcapsules indicated that dissoution was pH independent. Colloidal silica and isopropyl myristate formulations provided the best suspending characteristics of all aerosol formulations evaluated. Delivery rate, pressure, and evacuation testing demonstrated the usability and functionality of the aerosol. An evaluation was made on the effect on urinary excretion levels of 17-hydroxycorticosteroid when a physical admixture of the drug and timed-release microcapsules were sprayed on rabbits. The significantly higher 17-hydroxycorticosteroid levels obtained in urine of animals treated with the admixture after 1 day may have been attributed to both an immediate suppression of the endogenous steroid and the "spilling over" of excess dexamethasone. A significant difference also was found at the 90% confidence level among the 24, 48, and 72-hr 17-hydroxycorticosteroid levels in the admixture and the microcapsules, which substantiated the delayed effect of the latter.


Effect of flavoring oils on preservative concentrations in oral liquid dosage forms.

The partitioning of methyl-, ethyl-, propyl-, and butylparabens into flavoring oils from aqueous systems was studied. The partitioning is dependent on the concentration of the flavoring oil, the pH of the aqueous medium, and the nature and concentration of additives to the aqueous medium.


Transformation of 2,2'-anhydro-1-beta-D-arabinofuranosylcytosine induced by hydrogen peroxide.

2,2'-Anhydro-1-beta-D-arabinofuranosylcytosine (I) is a more potent and less toxic antineoplastic agent than is cytarabine (1-beta-D-arabinofuranosylcytosine) (II). The anhydronucleoside (I) was found to be readily transformed by hydrogen peroxide into 2,2'-anhydro-5-hydroxy-1-beta-D-arabinofuranosylcytosine (III) by treatment with 0.025 M hydrogen peroxide at a neutral and slightly basic pH range (pH 6-9) and at room temperature. It was converted into non-UV-absorbing substance(s) by hydrogen peroxide at an alkaline pH (pH 11). Since hydrogen peroxide is produced by redox reactions in all living cells, it may be responsible for the alteration of I. Such transformations by hydrogen peroxide were not observed with cytarabine.


Drug-biomolecule interactions: interactions of mononucleotides and polybasic amino acids.

Histones and ribosomal proteins are basic proteins that participate in gene regulation and protein synthesis, respectively. How these proteins interact with nucleic acids is not yet clear, although specificities in these interactions have been observed. Study of the interaction of mononucleotides with basic polyamino acids is one approach to understanding such interactions. The results of studies with the mononucleotides can help elucidate the normal molecular processes in biological systems and also shed light on some effects of drugs, such as puromycin and tubericidin, that are nucleotide derivatives. A review of studies on the interaction of mononucleotides and basic polyamino acids such as polylysine and polyarginine is presented. In addition, a short review of the self-associative properties of mononucleotides is given. Studies of the mononucleotide-polyamino acid interaction have involved a wide variety of techniques including equilibrium dialysis, NMR, optical rotatory dispersion, circular dichroism, and precipitate analysis.


Drug-biomolecule interactions: mechanism of ligand interactions with carbonic anhydrase studied by magnetic resonance relaxation and rapid reaction methods.

Kinetcs of interaction between the metalloenzyme carbonic anhydrase and either monovalent anions or aromatic sulfonamides were examined by three distinct fast reaction techniques: stopped flow, equilibrium perturbation, and magentic resonance relaxation. By correlating spectroscopic data on conformational and ionization equilibria of the complex and free species with the reaction kinetics, a relatively complete description of the mechanism can be presented. A proton-dependent equilibrium between two coordination forms of the free enzyme can be demonstrated spectroscopically. Anions selectively combine with the form predominating at low pH. For a series of carboxylate ligands, formate and substituted acetates, anion association is found to be three orders of magnitude greater than similar ligand substitution processes known in inorganic chemistry. For sulfonamide association, the attacking species are the form of carbonic anhydrase predominating at high pH and the neutral sulfonamide. Combination involving the neutral species is followed by loss of a proton to form the sulfonamido anion in the stabilized complex. This obligate proton transfer offers a probable explanation for the unique specificity of sulfonamides in inhibiting this enzyme. The anionic sulfonamido moiety can be shown to resemble closely a transition intermediate in the catalytic step of substrate hydration.


Drug-biomolecule interactions: proton magnetic resonance studies of complex formation between bovine neurophysins and oxytocin at molecular level.

Proton magnetic resonance spectroscopy was used to monitor individual amino acid residues in bovine neurophysin, in the nonapeptide hormone oxytocin, and in the complex formed between them. For neurophysin I alone, a normal titration curve for the C-2 proton resonance of the lone histidine residue was obtained with an apparent ionization constant of 6.9 addition of oxytocin to a solution of neurophysin I at pH 6.5 resulted in several changes in the spectrum. The effect on the histidine C-2 proton resonance signal indicated a slow exchange process between two states, probably representing a conformational change in the protein. The apparent pK of the histidine residue in the hormonal complex was shifted to 6.7, indicating a slightly more positive (less electron dense) environment for the histidine residue. Resonances of the single tyrosine residue of oxytocin were observed to broaden significantly, but not to shift appreciably, on the addition of neurophysin II. These observations may indicate involvement of the tyrosyl residue of oxytocin in the hormone-"carrier protein" interaction.


Drug-biomolecule interactions: interaction of gentamicin with lipid monomolecular films.

The interaction of gentamicin with monomolecular films of a series of biologically important lipids spread on an aqueous buffered subphase was studied. The surface pressure, pi, of these films was determined by the Wilhelmy plate method as a function of surface area, A, and pi-A curves were constructed. Changes in the pi-A characteristics in the presence of gentamicin were used as a measure of antibiotic-film interaction. No interaction was observed between gentamicin and films of cholesterol, egg lecithin, dipalmitoyl lecithin, phosphatidyl ethanolamine, stearyl alcohol, and bovine ceramides at all pH values studied. Stearic acid films showed no interaction with gentamicin at pH 5. At pH 7 and 8, a small increase in pressure (approximately 3 dynes/cm) was noted. A dramatic increase in surface pressure was observed in the presence of stearyl aldehyde films ranging from approximately 9 dynes/cm at pH 7,2 to 23 dynes/cm at pH 8.4. This effect was attributed to a Schiff-base reaction between the nonprotonated primary amino groups on the gentamicin molecule and the stearyl aldehyde. Further evidence was reported by the fact that the addition of glucose (which has been reported to participate in Schiff-base formation with amines) to the subphase inhibited the stearyl aldehyde-gentamicin interaction. Sucrose did not show a corresponding effect. The addition of sodium bisulfite, which reacts with aldehydes to form alpha-hydroxysulfonic acid, also inhibited the gentamicin-stearyl aldehyde interaction. It is postulated that Schiff-base formation is a step in the in vivo transport of gentamicin across the membrane of sensitive organisms.


Drug-biomolecule interactions: bioelectrometric study of the mechanism of carbachol interactions with the cornea and its relation to miotic activity.

The augmentation of carbachol miotic activity attributable to enhanced transcorneal absorption, which results from the action of cationic adjuvants included in ophthalmic vehicles, suggested a study of carbachol-corneal tissue interaction as a further step toward understanding the phenomenon. The present study was performed in vivo using an innocuous electrometric technique. A fixed charge density of the corneal epithelial surface versus carbachol concentration profile was obtained from the electrometric results; it revealed three distinct concentration regions defined by precipitous decreases of fixed charge over extremely small concentration ranges. This anomalous behavior is attributed to cooperative alterations in the binding affinities of fixed anionic sites on the tissue surface, which result in an all-or-none release of protons and/or other nicrocations. The unmasked anionic sites become reoccupied with carbachol except in the last region where the reoccupation by carbachol is competitive with other cations in the solution in contact with the surface. This behavior, postulated on the basis of the construction of a carbachol-tissue binding isotherm from which thermodynamic interaction affinities were computed, was corroborated by the observed dependency of the duration of miotic activity on carbachol concentration. Allosteric interactions between anionic binding sites, which are mediated through electron inductive and electrostatic field effects and likely involve a cooperative alteration in tissue water structure, are implicated as underlying the observed phenomena.


Drug-biomolecule interactions: drug toxicity and vitamin coenzyme depletion.

Thirteen pyridine compounds, phenylbutazone, and three salicylates were studied for their effects upon the turnover of 7-14C-nicotinamide dinucleotides in the mouse. The compounds were administered at equitoxic doses (LD25) to 7-14C-nicotinic acid- (niacin) pretreated mice, and the induced excretion of urinary-14C was analyzed in terms of total 14C and percentage of total 14C as known metabolites of nicotinic acid. Of the 17 compounds, 12 afforded significant alterations in the total 14C excreted and five of these caused alterations in the disposition of the 7-14C-nicotinamide endogenously liberated from the 7-14C-nicotinamide adenine dinucleotide pool. Comparative depletions of 14C from brain, lungs, liver, and kidneys were studied with 10 of the pyridine compounds. Several tissues were found to be the sources of the urinary-14C, with the lungs being the most accessible source. Some compounds had effects at doses less than the LD25's, as shown by increased hexobarbital sleeping time in acute experiments with rats. These pyridine compounds were initially considered to act at the level of the nicotinamide dinucleotides in the normal biosynthetic pathway (nicotinic acid site) and/or at the level of glycohydrolase (nicotinamide site). In view of the inclusion of nicotinic acid, nicotinamide, salicylic acid, and phenylbutazone in this correlation between toxicity and 7-14C-nicotinamide mobilization, it is not necessary that the formation of compounds analogous to the nicotinamide dinucleotides plays a significant role in the toxic manifestations of the nicotinamide analogs. The displacement of 7-14C-nicotinamide dinucleotides from their corresponding apoenzymes with subsequent metabolism of the dinucleotides could explain the noted increased 7-14C-nicotinamide dinucleotide turnover and depletion which led to the toxic effects.


Lidocaine hydrochloride absorption from a subcutaneous site.

Subcutaneous disappearance of lidocaine hydrochloride was followed as a function of time using a specially designed "closed" subcutaneous absorption cell affixed to anesthetized rats. Unbuffered, stirred lidocaine hydrochloride solutions in cells open to the atmosphere were previously shown to increase in pH with time because of carbon dioxide loss. The closed cell was designed to prevent this loss, but pH shifts still occurred, making the derivation of a simple pharmacokinetic absorption model impossible. Because the pH of the solution shifted to higher pH values, the data suggest that precipitation of lidocaine base may have occurred in some experiments.


Fluorometric assay of bethanidine in plasma.

A fluorometric method for determining bethanidine in blood plasma is described. The bethanidine is extracted into chloroform, a drug-dye complex with eosin Y is formed, and the fluorescence is measured (excitation, 535 nm; fluorescence, 560 nm). The assay detects 0.02 muM bethanidine (4 ng/ml) in plasma. The relative fluorescence of several body constituents and antihypertensive drugs is negligible. The plasma levels of bethanidine in four hypertensive patients receiving this drug were measured.


Automated system for analytical microbiology V: calibration lines for antibiotics.

The accuracy of an automated system for the microbiological assay of antibiotics was increased by improvement attendant to connection to an on-line computer. The system was used to investigate the suitability of four forms of interpolation formulas by assaying for chlortetracycline and erythromycin. The calibration lines were prepared as point-to-point straight-line approximations and as cubic equations. Cubic equations through four calibration points were preferred. Since the automated system was a four-channel instrument, a separate response line was prepared for each channel. Combining the four response lines into one could substantially degrade the accuracy and precision of assays. A new general equation relating the response of the test organism to concentrations of active materials was used to account for factors in addition to the antibiotic upon the dose-response line. Some of these factors were: diluents, growth substances, relative proportions of mixed antibiotics, pH and buffer capacities of the sample solution and assay broth, salts, and organic compounds in samples and not in standard solutions. The equation was used to show under what conditions the dose-response lines of mixtures and single-component antibiotics could be the same. It could also account for the nonspecific nature of turbidimetric assays. The equation showed assay biases to be caused not by differences in composition of antibiotics in standards and samples but by differences in other substances affecting growth of the test organism. A new dose-response line applicable to assays using Klebsiella pneumoniae was described.


Ultracentrifugal study of effect of sodium chloride on micelle size of fusidate sodium.

Apparent micellar molecular weights were determined with the antibiotic fusidate sodium by ultracentrifugation in varying counterion concentrations (Na+). The effects of buffer salts, pH, sodium chloride concentration, and drug concentration were studied. The results strongly support the concept of the formation of primary micelles composed of five monomer units, followed by aggregation of the pentomers into larger micelles as salt concentration increases.


Synthesis of potential adrenergic blocking agents: 2-substituted aminomethylnaphthol(2,3-b)-1,4-dioxans.

Eleven 2-substituted aminomethylnaphtho(2,3-b)-1,4-dioxans were synthesized. The nucleophilic displacement of 2-tosyloxymethylnaphtho(2,3-b)-1,4-dioxan by appropriate amines was carried out using dimethyl sulfoxide as the solvent. Preliminary pharmacological evaluation revealed a potentiation of norepinephrine at low doses and a noncompetitive antagonism at high doses in the rat vas deferens and a dose-related hypotensive action of short duration in the anesthetized rat.


Liquid chromatography in pharmaceutical analysis III: separation of diuretic-antihypertensive mixtures.

High-pressure liquid chromatography was used to optimize the resolution of therapeutic agents commonly found in antihypertensive preparations. Seven widely prescribed drugs were investigated. The compounds were chromatographed on reversed-phase octadecyltrichlorosilane (C18) or diphenyldichlorosilane (phenyl) columns, using mixtures of acetonitrile or absolute methanol and distilled water buffered with ammonium acetate, ammonium chloride, or ammonium carbonate. By calculating approximate resolution values, the separation of selected drug mixtures can be predicted.


Rapid fluorometric determination of procainamide hydrochloride dosage forms.

A fluorometric procedure for procainamide hydrochloride was developed, and it offers improvements in ease, speed, and sensitivity over the official method. The new procedure is based on the reaction with fluorescamine in aqueous medium at pH 7.5 to form a fluorophore, with activation and emission wavelengths of 400 and 485 nm, respectively. The fluorescence is linear (r = 0.999) over the 0. 04-1 mug/ml concentration range and is stable for at least 2 hr. Recovery data appeared to be accurate, quantitative, and reproducible. The overall recovery was 99.8% with a standard deviation of +/-1.14 (n = 5). The method was successfully applied to commercially available dosage forms.


Synthesis and pharmacological activity of 5-substituted 2-(N,N-dialkylaminoethyl)amino- and 2-N-methylpiperazinyl-1,3,4-thiadiazoles.

5-Substituted 2-amino-1,3,4-thiadiazoles were transformed to their corresponding 2-bromo derivatives. The reaction of the 5-substituted 2-bromo-1,3,4-thiadiazoles with N,N-dialkylaminoethylamines or N-methylpiperazine afforded the corresponding amino-1,3,4-thiadiazole derivatives. All prepared compounds displayed antihistaminic, anticholinergic, and norepinephrine-potentiating activities.


Interaction of substituted benzoic acids with polysorbate 20 micelles.

Equilibrium solubilities of a series of substituted benzoic acids in different concentrations of polysorbate 20 at controlled pH were measured. The maintenance of pH was achieved using a pH-stat assembly. A linear relationship was found between the amount of benzoic acid solubilized and surfactant concentration. As solubilizate polarity increased, the amount solubilized also increased. Solubility data were analyzed, and the interaction between solubilizate molecules and micelles was calculated in terms of partition coefficients of ionized and unionized molecules between aqueous and micellar phases. A linear relationship between pi values (log partition coefficients) of functional groups and aqueous-micellar partition coefficient was found.


Confirmation of iminoacridan structure of singly protonated 9-aminoacridine.

The occurrence of the second absorption band of singly protonated 9-aminoacridine, which arises from an acridinium ring-localized transition, at anomalously short wavelength indicates the disruption of the aromaticity of the central ring of the singly charged cation. The shifting of the two longest wavelength absorption bands and the fluorescence band of 10-methyl-9-aminoacridine monocation, a model of singly protonated 9-aminoacridine which is constrained to dissociate from the exocyclic nitrogen atom, to shorter wavelengths, upon dissociation, indicates the imine-like nature of the 10-methyl derivative. Thes observations support the conclusion that the predominant site of positive charge in singly protonated 9-aminoacridine is the exocyclic nitrogen atom, even though the heterocyclic nitrogen atom is the site of protonation of the neutral molecule.


High-pressure liquid chromatographic analysis of triflubazam and its metabolites in human and animal blood and urine.

A high-pressure liquid chromatographic method is described for analyzing triflubazam [1-methyl-5-phenyl-7-trifluoromethyl-1H-1,5-benzodiazepine-2,4(3H,5H)-dione] and its primary metabolites in blood and urine. Adsorption chromatography, using pellicular silica gel as the stationary phase and dioxane-isooctane as the mobile phase, permitted rapid sample analysis. After extraction of blood and urine samples with toluene, quantitation is achieved using liquid chromatography with an internal standard. The method is sensitive above 50 ng/ml of triflubazam and its known metabolites. Recoveries for all compounds from blood or urine averaged above 95 percent. The specificity of the method was established by collecting samples separated by liquid chromatography and characterizing them by mass spectrometry. Human and animal data are presented to illustrate the utility of the method.


Effect of self-association on rate of penicillin G degradation in concentrated aqueous solutions.

The apparent rate of degradation of penicillin G potassium micellar solutions of 500,000 units/ml, a concentration commonly encountered in vials reconstituted for storage in the refrigerator, was investigated and compared to that of nonmicellar solutions of 8000 units/ml at 25 degrees, ionic strength of 1.1 M, and pH range from 5.0 to 9.5. In the micellar solutions the apparent rate of the H+-catalyzed degradation was increased twofold but that of water- and OH minus-catalyzed hydrolysis was decreased two- to three-fold. Consequently, the pH-rate profile of the micellar solutions was shifted to higher pH values and the pH of minimum degradation was found to be at 7.0 compared to 6.5 for the nonmicellar solution of the same ionic strength. Compared at their respective pH-rate profile minima, micellar penicillin G is 2.5 times as stable as the nonmicellar solution under the conditions of constant pH and ionic strength.


Nonisothermal kinetic studies III: rapid nonisothermal-isothermal method for stability prediction.

A continuous nonisothermal-isothermal method for stability prediction was developed. The approach yields all necessary parameters for prediction, including reaction order. The experimental procedure involves changing the temperature of the samples being studied until degradation is rapid enough to proceed at a convenient isothermal rate for a sufficient number of half-lives with adequate analytical sensitivity so that the reaction order can be unambiguously determined. The analytical information obtained during the nonisothermal and isothermal portions of the experiment is utilized without curve matching in calculating the activation energy and determining the reaction order, reaction rate, and stability prediction at any desired temperature. Model experiments include the acid-catalyzed hydrolysis of acetylcholine bromide and the inversion of sucrose.


Liquid chromatography in pharmaceutical analysis IV: determination of antispasmodic mixtures.

Parameters associated with the separation of antianxiety-antispasmodic agents were investigated using high-pressure liquid chromatography. Eight widely prescribed drugs were studied. The compounds were chromatographed on reversed-phase octadecyltrichlorosilane (C18) or diphenyldichlorosilane (phenyl) columns, using mixtures of absolute methanol and distilled water buffered with ammonium dihydrogen phosphate, ammonium acid phosphate, or ammonium carbonate. A mixture of phenobarbital-propantheline bromide was selected to demonstrate the utility of the separation and quantification method. The mixture was chromatographed on a phenyl column, using absolute methanol-aqueous 1 percent ammonium dihydrogen phosphate (60:40) (pH 5.85) at a flow rate of 1.4 ml/min. Each determination can be achieved in approximately 15 min with an accuracy of 1-2 percent.


Colorimetric determination of peptide antibiotics: in-process assay of cyclic octapeptidic antibiotics in fermentation broths.

A spectrophotometric method is presented for monitoring the biosynthesis of a new complex of cyclic octapeptidic antibiotics in fermentation broths. The method is based on the extraction of antibiotic from alkaline broth with butanol. An ion-pair, formed between the octapeptides and bromthymol blue, is extracted into chloroform from a solution buffered to pH 7.5. The absorbance of the colored solution is measured at 420 nm. Results are in good agreement with those obtained by microbiological assay. The method is also applicable to other peptidic antibiotics such as polymyxin B and gramicidin.


The effects of chronic ganglion blockade and chronic cholinesterase inhibition on the sensitivity of rabbit stomach muscularis to cholinergic and adrenergic agonists.

The EC50 values, KA values and efficacies (e) of selected agonists have been determined in strips of stomach muscularis from control, chlorisondamine-pretreated and O, O-diethyl S[2(ethylthio)ethyl]phosphodithioate (disulfoton)-pretreated rabbits. Strips from chlorisondamine-pretreated animals were supersensitive to carbachol but normosensitive to phenylephrine; the e but the KA of carbachol was affected by this treatment. The KB of atropine was unchanged. Strips from animals treated with disulfoton were subsensitive to phenylephrine but normosensitive to amidephrine and carbachol; both the e and KA of phenylephrine appeared to be elevated by this pretreatment. The KB of phentolamine remained unchanged. These results indicate that the chlorisondamine-induced supersensitivity is the result of a change beyond the level of the cholinergic receptors. In contradistinction, the subsensitivity to phenylephrine after disulfoton pretreatment may result at least in part, from a qualitative change in the alpha adrenergic receptors in the stomach muscularis.


Release of norepinephrine and dopamine-beta-hydroxylase by nerve stimulation. V. Enhanced release associated with a granular effect of a benzoquinolizine derivative with reserpine-like properties.

A reserpine-like agent, 2-hydroxy-2-ethyl-3-isobutyl-9,10-dimethoxy-1,2,3,4,6,7,-hexa-hydro-11b-H-benzo[a]quinolizine (BQZ), at concentrations that do not inhibit phosphodiesterase activity, produces a marked increase in the outflow of 3-H-dihydroxyphenyl-ethyleneglycol from the isolated, perfused cat slpeen prelabeled with 3-H-norepinephrine (3-H-NE). The increased intraneuronal levels of catechols probably account for the inhibition of the conversion of 1-minus14C-L-tyrosine to 1-minus14C-L-dopa which is observed in the presence of the drug. In addition, in the presence of 0.9 muM BQZ, there is a 2.5- to 3-fold increase in the nerve stimulation-mediated overflow  of NE, 3-H-NE, total 3-H and dopamine-beta-hydroxylase activity. A highly significant positive correlation was observed between the increase in the spontaneous release of 3-H and the enhanced exocytotic release of transmitter by nerve stimulation. These results suggest that either a primary alteration of the storage granule membrane or the subsequent enhanced intraneuronal levels of NE or NE metabolites may be responsible for the enhanced exocytotic release by nerve stimulation. In the presence of 0.9 muM BQZ, addition of 3 muM cocaine produces an increase in the nerve stimulation-mediated overflow of NE and an inhibition of the formation of 3-H-dihydroxyphenylethyleneglycol. In addition, there is a 20 to 30% decrease in the overflow of 3-H and dopamine-beta-hydroxylase activity and a marked delay in the outflow of the enzyme elicited by nerve stimulation. These results suggested that, in the presence of BQZ, a large fraction of the NE released during nerve stimulation is recaptured into the nerve terminals where it is subsequently metabolized to 3-H-dihydroxyphenylethyleneglycol. The enhanced exocytotic release of NE, the extensive presynaptic metabolism of the recaptured transmitter subsequent to release by nerve stimulation, and inhibition of norepinephrine synthesis all appear to contribute to the accelerated depletion of tissue NE which is observed when the splenic nerves are stimulated in the presence of 0.9 muM BQZ. These results provide an explanation for the accelerated depletion of tissue NE in animals treated with reserpine-like compounds when the sympathetic innervation is intact.


Effects of reserpine on activities and amounts of tyrosine hydroxylase and dopamine-beta-hydroxylase in catecholamine neuronal systems in rat brain.

Reserpine (10 mg/kp i.p.) increased the activities of the enzymes tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase, but not dopa decarboxylase, 2- to 3-fold in the nucleus locus ceruleus of rat brain. The TH response was dose-dependent, reached a maximum by 48 hours and recovered by 3 weeks. The increased activities of TH and dopamine-beta-hydroylase were shown by immunotitration with specific antibodies to each enzyme to be due entirely to increased accumulation of specific enzyme protein. At a time when the reserpine-elicited accumulation of TH was increased 300% in the locus ceruleus, activity of the enzyme only increased 20% in hypothalamus and not at all in substantia nigra or caudate nucleus. Reserpine increased the accumulation of TH, primarily in the cell bodies and to a far less degree in the terminals of neurons of locus ceruleus but not in dopaminergic neurons of the nigrostriatal system. The time course of enzyme accumulation parallels that of depletion of monoamines in brain.


Effects of ethanol on neurotransmitter release by rat brain cortical.

Using a double label technique to preload rat brain cortex slices with different radioactive neurotransmitters (or precursor choline), we have studied the effects of ethanol on the electrically stimulated release of these transmitters. Ethanol inhibited the release of these transmitters, acetylcholine being the most sensitive and occurring at concentrations compatible with moderate to severe intoxication in the rat (IC50 equals 0.17 M). The order of sensitivity to ethanol was acetylcholine greater than serotonin greater than dopamine greater than norepinephrine greater than glutamate greater gamma-aminobutyric acid. Two higher alcohols and two barbiturates were also shown to have a greater inhibitory effect on the stimulated release of acetylcholine than of norepinephrine. The concentrations of all the drugs tested required for 50% inhibition of release of acetylcholine and norepinephrine correlated well with their lipid solubility when corrected for their molecular volumes. The effect of tetrodotoxin and of ouabain on neurotransmitter release was also studied. A comparison of the effects of these two drugs with those of ethanol suggests that the effect of ethanol is consistent with an inhibition of the action potential by this drug, although a specific effect of ethanol on the excitation-coupling process at the synapse cannot by discarded.


Effect of hypoxemia on responses to norepinephrine and angiotensin in coronary and muscular vessels.

The purpose of this study was to determine the relative effects of acute hypoxemia on constrictor responses to norepinephrine and angiotensin in two vascular beds, the coronary and skeletal muscle. The left circumflex coronary and gracilis muscle arteries of anesthetized dogs were perfused at constant flow. Practolol or propranolol was administered to block indirect myocardial effects of norepinephrine on coronary resistance. When Po2 of arterial blood perfusing the coronary and muscle beds was reduced from 101 to 44 mm while systemic Pco2 remained normal, constrictor responses to both norepinephrine and angiotensin were inhibited in coronary vessels but not in muscle vessels. When local Po2 was reduced to 27 mm Hg, inhibition of responses was again observed in the coronary circulation with both drugs; in the muscle, responses to angiotensin but not to norepinephrine were depressed significantly. Since intracoronary infusion of adenosine increased, rather than inhibited, vasoconstrictor responses to angiotensin, it is unlikely that release of adenosine during hypoxemia accounts for inhibition of vasoconstriction in the coronary circulation. Indomethacin did not alter the inhibition of coronary vasoconstrictor responses to angiotensin during hypoxemia, which suggests that releease of prostglandins during htpoxemia is not the primary mechanism for inhibition of coronary vascular responses. When contractions in the gracilis muscle were produced by electrical stimulation, vasconstrictor responses to norepinnephrine were inhibited during hypoxemia. We conclude that depression of constrictor responses by hypoxemia is more pronounced in the coronay circulation than in resting muscle, but when muscle is contracting, vasoconstrictor responses are impaired during hypoxemia.


Digitalis toxicity during acute hypoxia in intact conscious dogs.

Intact, conscious dogs were studied under normal and hypobaric conditions to assess the influence of acute hypoxia on the ability of the animals to tolerate ouabain. Animals were made acutely hypoxic by exposure to hypobaric conditions in a chamber maintained at 446 mm Hg. The ability of the dogs to tolerate ouabain was determined by administering intravenously 7.5 mug/kg of the drug as a loading dose followed by infusion at a rate of 3.0 mug/kg/min to an end point consisting of the development of ventricular or atrioventricular junctional tachycardia. Eight dogs, each acting as its own control, were studied under normoxic and acutely hypoxic conditions. During hypoxia, mean arteriol pO2 decreased to 39 plus or minus 1 (S.E.) mm Hg from 80 plus or minus 1 mm Hg at sea level (P less than .001). The cumulative toxic dose of ouabain was modestly but significantly less (P less than .05) during acute hypoxia (71.7 plus or minus 4.3 mug/kg) compared with normoxic (79.2 plus or minus 4.1 mug/kg) conditions. In these experiments a marked hyperventilation response to ouabain was observed just before onset of toxicity which resulted in a pronounced rise in mean arterial pH (normoxia: 7.39 plus or minus 0.01 to 7.72 plus or minus 0.01; hypoxia: 7.48 plus or minus 0.01 to 7.71 plus or minus 0.04) and fall in pCO2 (normoxia: 41 plus or minus 1 to 14 plus or minus 1 mm Hg; hopoxia: 34 plus or minus 1 to 16 plus or minus 2 mm Hg). Ouabain-induced increases in systemic arterial pressure were comparable in normal and acutely hypoxic animals. Thus, acute hypoxia in unanesthetized dogs exposed to hypobaric conditions results in a decrease of only 10% in the ouabain dose required to produce cardiac arrhythmias, and toxic doses of ouabain produce a striking respiratory alkalosis.


Receptor binding and pharmacological activity of opiates in the guinea-pig intestine.

A comparison was made between the affinities of a wide range of opiate agonists, mixed agonist-antagonists and antagonists for opiate receptor binding sites in the guniea-pig intestine longitudinal muscle and myenteric plexus preparation, and their pharmacological potency in influencing the electrically induced contraction of this in vitro functional system. The relative affinities of drugs and the degree of stereospecificity for intestinal binding sites are closely similar to these properties in the brain. Receptor binding correlates extremely well with pharmacological potency, both for agonists and antagonists, indicating that binding involves pharmacologically relevant opiate receptors. Pharmacological activity correlates best with receptor binding assayed in the presence of sodium.


Postnatal elevation of brain tyrosine hydroxylase activity, without concurrent increases in steady-state catecholamine levels, resulting from dl-alpha-methylparatyrosine administration during embryonic development.

Increased specific activity of tyrosine hydroxylase (TH) in the brains of embryonic and 29-day-old chickens results from exposure to reserpine during the early stages of embryogenesis. We have also reported significant increases in the steady-state concentrations of catecholamines (CAs) in the brains of these 29-day-old chickens, suggesting permanent alterations in the control mechanisms during a critical period of development. The specificity of embryonic CA depletion in the above findings was examined usind dl-alpha-methyl-para-tyrosine (AMPT) as a depleting agent. AMPT, injected in varying doses into the yolk sac of fertilized chicken eggs prior to incubation, caused embryonic CA depletion by day 10 of embryogenesis but repletion had occurred by 20 days of embryogenesis. TH activity in whole brain and brain parts was elevated in a dose-related fashion at 29 days postnatally by AMPT. However, no changes in steady-state CA levels in whole brain were observed at this time after AMPT. Differences in the responses to reserpine and AMPT are discussed with respect to their pharmacological actions. The data support the contention that early embryonic CA depletion can result in long-term increases in TH activity postnatally, but steady-state levels of product need not necessarily be altered.


Effect of thioridazine, clozapine and other antipsychotics on the kinetic state of tyrosine hydroxylase and on the turnover rate of dopamine in striatum and nucleus accumbens.

In rats, a single injection of antipsychotic drugs produced a transitory change in the kinetic state of tyrosine hydroxylase (TH) in striatum and nucleus accumbens. The affinity of TH for 2-amino-4-hydoxy-6,7-dimethyl-5,6,7,8-tetrahydropterine (DMPH4) and the Vmax with respect ot tyrosine were increased. The relative potencies of anti-psychotics to change the kinetics of TH in striatum and nucleus accumbens when injected into rats were measured in the presence of 0.4 mM DMPH4. The doses of methiothepin, pimozide and halopridol which increased the affinity for DMPH4 of striatal TH were lower than those required to produce a similar change in nucleus accumbens. In contrast, thioridazine and clozapine were more effective in nucleus accumbens than in striatum. Chlorpromazine was equally active in these two tissues. Haloperidol increased the turnover rate of dopamine in striatum with doses that are relatively smaller than those required in the nucleus accumbens. Clozapine was more active in increasing turnover rate of dopamine in nucleus accumbens; the activity of chlorpromazine in these two tissues was equal. These results suggest that antipsychotics with high incidence of extrapyramidal side effects affect the nigrostriatal dopaminergic pathway selectively.


The activity of tyrosine hydroxylase in intact adrenergic neurons of the mouse vas deferens.

A procedure is described for measuring the activity of tyrosine hydroxylase in the intact adrenergic neurons of the mouse vas deferens. In this procedure, the L-dopa-1-14C which is formed from L-tyrosine-1-14C by the action of tyrosine hydroxylase is selectively and quantitatively decarboxylated by endogenous aromatic-L-amino acid decarboxylase. Although considerable tyrosine hydroxylase activity can be demonstrated with the intact mouse vas deferens in the absence of exogenous tetrahydropterin cofactor, the addition of 2-amino-4-hydroxy-6,7-dimethyltetrahydropteridine results in increased activity. Exogenous norepinephrine inhibits the activity of tyrosine hydroxylase in the intact mouse vas deferens and this inhibitory effect is competitively antagonized by 2-amino-4-hydroxy-6,7-dimethyltetrahydropteridine. When the vesicular catecholamine uptake mechanism is blocked by treatment of mice with 5 mg/kg of reserpine 24 hours prior to sacrifice, the activity of tyrosine hydroxylase in intact vas deferens is reduced and the inhibitory effect of exogenous norepinephrine is enhanced. Inhibition of monoamine oxidase with 0.15 mM pargyline does not affect the activity of tyrosine hydroxylase in the intact mouse vas deferens when the vesicular catecholamine uptake mechanism is intact but has a pronounced inhibitory effect following reserpine treatment. These observations lend further support to the conclusion that the activity of tyrosine hydroxylase in the intact adrenergic neuron is inversely related to the catecholamine concentration within an extravesicular pool. They also suggest that the catecholamines tend to accumulate within this extravesicular pool and thus become accessible to the action of monoamine oxidase when the vesicular uptake mechanism is inactivated or when the vesicular stores are filled to capacity.


The absence of renal bicarbonate reabsorption maxima during carbonic anhydrase inhibition.

Present studies were performed to examine the effect of carbonic anhydrase inhibition on bicarbonate reabsorption under experimental conditions where extracellular fluid volume expansion was minimized. The data showed no tubular maximum for bicarbonate reabsorption in the normal state or after carbonic anhydrase inhibition. The data support a model which assumes that the bicarbonate reabsorption is accomplished by two processes. One process is independent of protonation from H+ secretion into the tubule and probably involves reabsorption of bicarbonate ion as such. This process has an unlimited capacity for reabsorption of bicarbonate. The contribution of this process increases with an increase in plasma bicarbonate. The second process is dependent on protonation, through the intracellular hydration of carbon dioxide. The relative contribution, through the intracellular hydration of carbon dioxide. The relative contribution of this process is normally about 33% and decreases with increased plasma bicarbonate.


Molecular mechanisms in the actions of morphine and viminol (R2) on rat striatum.

Analgesic doses of morphine and viminol R2 increase the turnover rate of dopamine (DA) in rat striatum but fail to increase the striatal concentration of adenosine 3',5'-monophosphate (cAMP) or the affinity of tyrosine hydroxylase (TH) for the pteridine cofactor. When morphine is added to striatal homogenates, it changes neither the basal activity of adenylate cyclase nor the enzyme activation by DA. Similarly to morphine, haloperidol enhances the turnover rate of striatal DA, but unlike morphine it increases the affinity of TH for the pteridine cofactor and blocks the in vitro activation of striatal adenylacte cyclase by DA. Morphine (52 mumol/kg i.p.), viminol R2 (7 mumol/kg i.p.) or haloperidol (2.6 mumol/kg i.p.) fails to increase the striatal cAMP contrations. However (+)-amphetamine (4.8 mumol/kg i.p.) increases DA turnover rate and the striatal cAMP content, but, in doses up to 12.8 mumol/kg i.p., it fails to change the affinity of TH for the pteridine cofactor. This study shows that although (+)-amphetamine, haloperidol and morphine increase the turnover rate of striatal DA each drug possesses a specific profile in its action on molecular mechanisms that control the function of striatal dopaminergic synapses.


Modification by lithium of transmitter release at the neuromuscular junction of the frog.

Complete or partial replacement of Na+ by Li+ resulted in a progressively developing increase in the amplitude and quantal content of end-plate potentials of the frog neuromuscular junction. Analysis of frequency facilitation curves and estimations of the binomial parameters of release indicate that Li+ caused an increase in the probability of transmitter release. Li+ also caused a time dependent increase in the frequency of miniature end-plate potentials. The responsiveness of the miniature end-plate potentials to Li+ was depressed by elevated Ca++ and enhanced by elevated K+. Collectively, the effects of Li+ on transmitter release can be attributed to the accumulation by the nerve terminals of Li+ resulting on an increased level of intracellular Ca++.


The effects of maternal hypercapnia on foetal oxygenation and uterine blood flow in the pig.

1. The purpose of this investigation was to determine the effects of maternal hyperoxaemia and hypercapnia on the uterine vascular bed and foetal oxygenation in the large white sow at 80-90 days gestation. 2. When maternal hyperoxaemia was induced with 100% oxygen, there was a highly significant rise in the maternal arterial oxygen tension, but no other significant blood gas or vascular changes were observed. 3. When mild maternal hypercapnia was superimposed on maternal hyperoxaemia (oxygen plus 6% carbon dioxide), the oxygen tension and saturation of both the maternal uterine venous and foetal umbilical venous bloods were found when severe hypercapnia was induced (oxygen plus 50% carbon dioxide) but in this case all blood samples showed dramatic changes in PCO2 and pH. These changes were accompanied by an increase in the systemic blood pressure and uterine blood flow, and a decrease in uterine vascular resistance. 4. When mild hypercapnia was induced without hyperoxaemia (air plus 5% carbon dioxide) significant increases were recorded in the oxygen tension and saturation of uterine venous and foetal umbilical venous bloods. Systemic and uterine vascular resistance fell. 5. It was concluded that the increased foetal oxygen tension during maternal hypercapnia was the result of the increased uterine blood flow and greater mass delivery of oxygen to the placenta, so that once the oxygen requirements of the placental tissues themselves were exceeded there would be an increased oxygen gradient at the site of gas exchange. 6. Carbon dioxide concentration in arterial blood plays an important role in determining blood flow through the pregnant uterus in the sow.


Intracellular pH and distribution of weak acids across cell membranes. A study of D- and L-lactate and of DMO in rat diaphragm.

1. The steady-state distribution ratios of D- and L-lactate between fibre water and external fluid were measured in 'intact' rat hemidiaphragm preparations exposed for 2-5 hr to a variety of solutions of normal ionic strength and osmolarity. The studies were designed to minimize the effects, on these distributions, of conversion of lactate and of generation of lactic acid by the muscle. 2. At D-lactate concentrations between 2.3 and 118 mM, at normal pH and PCO2, the D-lactate distribution ratio, obtained from the distribution of [2-(3)H]D-lactate was independent of concentration; it averaged 0.349. As the concentration of D-lactate was reduced below 2.3 mM, its distribution ratio progressively fell to less than 0.1. 3. Radiochromatograms of extracts of incubated muscle showed that the tritium label was not attached to substances other than lactate. 4. At L-lactate concentrations of 59 and 108 mM, at normal pH and PCO2, the average L-lactate distribution ratios, obtained by enzymatic analysis, were respectively 0.395 and 0392. 5. At 19-89 mM D-lactate, depolarizing the muscle fibres by high K(49-127 mM), at normal pH, PCO2, and [K]0[Cl]0 product, only slightly affected the D-lactate distribution ratio which averaged 0.405. 6. The D-lactate distribution ratio and intracellular pH (pHi), obtained with the DMO method (5,5-dimethyl-2,4-oxazolidinedione), were measured in thirty sets of studies after exposure of the muscle to solutions buffered to pH values ranging between 5.99 and 8.13, and containing 18.5-118 mM D-lactate and 6-129 mM-K. 7. The relation between the distribution ratios of D-lactate ([TL]i/[TL]O) and of H ions ([Ho/[H]i) in these studies could be expressed by [TL]i/[T]O = 0.646 [H]o/[H]i+0.056. 8. It was concluded that it is predominantly the undissociated lactic acid molecules, rather than the much more numerous lactate ions, which permeate the fibre membrane; and that the steady-state lactate distribution ratio is determined by the transmembrane pH gradient, and not by membrane potential. 9. The expression of the steady-state lactate distribution ratio as function of relative membrane permeabilities of lactic acid molecule and lactate ion, membrane voltage, and internal and external H ion concentrations indicates that a finite permeability to the ion, three or four orders of magnitude less than that to the molecule, is compatible with the experimental data. When both ion and molecule of any weak acid are permeable, they act as a carrier system for the movement of protons down their electrochemical gradient. 10. Near-maintenance of pHi in the face of high fibre D-lactate (19-44 mM) and DMO (8-42 mM) indicates stimulation of proton extrusion by acid loans. 11. This extrusion is insensitive to ouabain, as judged from the lack of effect of the drug of pHi with acid loading.


A branched-chain amino acid aminotransferase from the rumen ciliate genus Entodinium.

A branched-chain amino acid aminotransferase was extracted from rumen ciliates of the genus Entodinium and was partially purified by Sephadex G-200, DEAE-cellulose and DEAE-Sephasex A-50 column chromatography. The purified enzyme was active only with leucine, isoleucine and valine, and required pyridoxal phosphate as cofactor. The amino acids competed with each other as substrates. The enzyme had optimal activity at pH 6.0 in phosphate buffer. The Km values for the substrates and cofactor are as follows: 1.66 for leucine; 0.90 for isoleucine; 0.79 for valine; 0.29 mM for alpha-ketoglutarate; and 0.1 muM for pyridoxal phosphate. Enzyme activity was inhibited by rho-chloromercuribenzoate and HgCl2. Gel filtration indicated the enzyme to have a molecular weight of 34,000.


Mixed IgM-IgG cryoglobulinemia terminating in polyarteritis nodosa.

A case of mixed IgM-IgG cryoglobulinemia and polyarteritis nodosa is described. The patient exhibited non-deforming arthritis, Raynaud's phenomena, cutaneous vasculitis, and a sensory neuropathy.. The terminal phase of the illness was characterized by hypertension and retroperitoneal hemorrhage, with widespread large vessel arteritis. The isolated cryoprecipitate contained IgM, IgG, and C3 and possessed rheumatoid factor activity. Mild reduction in serum complement (CH50 and C3) was noted on one occasion. The evidence that these cryoprecipitable proteins may be acting as immune complexes and contributing to the arterial lesions is reviewed.


Synthesis and biological evaluation of some 10-substituted 2,3-dihydroimidazo[2,1-b]quinazolin-5(10H)-ones, a new class of bronchodilators.

On treatment of N-substituted isatoic anhydrides with 2-methylmercaptoimidazolines, 10-substituted imidazo[2,1-b]quinazolin-5(10H)-ones are obtained. Several members of this class exhibited pronounced broncholytic activity. The structure-activity relationships (based on results obtained in the guinea pig histamine aerosol test) of these nonsympathomimetic bronchodilators are discussed. In addition, the detailed pharmacological evaluation of two analogs found to be five to ten times more active than theophyline as bronchodilators without having central nervous system or cardiovascular side effects is described.


Synthesis and biological evaluation of fragmented derivatives of tetrahydroisoquinolines. 2. Trimetoquinol studies.

The synthesis of N-(3',4',5'-trimethoxyphenylethyl)-3,4-dihydroxyphenylethylamine (2) and 1-(3,4,5-trimethoxybenzyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (1) is presented. Comparative pharmacological effects of the optical isomers of 1 and compound 2 are reported in guinea pig atria, rat adipose tissue, guinea pig trachea, and guinea pig aortic strip preparations. In the beta-adrenoreceptor preparations, (-)-1 was shown to be more potent than (+)-1 or 2. Racemic 1 and 2 were shown to have equal alpha-antagonist properties in the inhibition of norepinephrine-induced contractions of guinea pig aorta.


3-Substituted 2-formylquinoxaline 1,4-dioxides.

The methylnitrone of 3-methyl-1,4-dioxidoquinoxaline-2-carboxaldehyde (1) has been exceptional antibacterial activity in vivo. Derivatives of 3-hydroxymethyl-1,4-dioxidoquinoxaline-2-carboxaldehyde and 3-acetoxymethyl-1,4-dioxidoquinoxaline-2-carboxaldehyde were prepared. Several of these compounds were found to be antibacterial agents of the same order of activity as I.


Microelectrometric titration measurement of the pKa's and partition and drug distribution coefficients of narcotics and narcotic antagonists and their pH and temperature dependence.

The pKa's, partition coefficients, and drug distribution coefficients (apparent partition coefficients) have been investigated for a number of narcotics and, where possible, for their congener narcotic antagonists.  These studies were carried out by a microelectrometric titration technique as a function of temperature and pH.  This method enables one to determine not only the dissociation constants to deconvolute overlapping pKa's, but also to determine the solubilities of oil-water distribution of these various drugs.  The drug distribution coefficients displayed marked sensitivity to pH at values which span the range of attainable human physiological pH values.  This has significant pharmacological implications for proper choice and scaling of drug dosages under various clinical situations.  The partition coefficients and drug distribution coefficients were noticeably different at 20 degrees (where such measurements are customarily made) than at 37 degrees (body temperature).  Furthermore, various drugs exhibit very nonequivalent increases in drug distribution coefficients with increasing temperature, ranginf from 21% for morephine to 200% for naltrexone.  This nonregularity indicates that it will not be valid to extrapolate by any constant factor the measurements made at lower temperatures.  Even the true partition coefficients increase with temperature from 20 degrees to 37 degrees.  There is more of a difference in the drug distribution coefficients for naloxone and naltrexone than might have been expected from the similarities in their structures with naltrexone being significantly less lipophilic than naloxone.  This would imply that this would lead to naloxone having a more rapid onset for antagonist activity and likewise a shorter duration of action than naltrexone.


Synthesis and biological activity of spin-labeled analogs of biotin, hexamethonium, decamethonium, dichlorisoproterenol, and propranolol.

Spin-labeled analogs of biotin (vitamin H), hexamethonium, decamethonium, dichlorisoproterenol, propranolol, and primaquine containing the nitroxide free radical have been synthesized and tested for biological activity. The four spin-labeled analogs of biotin, 4-biotinamido-2,2,6,6-tetramethyl-1-piperidinyloxy (IV), 3-biotinamido-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (V), 3-biotinamidomethyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (VI), and 4-(biotinylglycyl)amino-2,2,6,6-tetramethyl-1-piperidinyloxy (VII), all interacted with avidin, a specific biotin binding protein found in raw egg white, at the same sites as did biotin itself. An unsymmetrical decamethonium spin label (XVIII) in which one of the quaternary methyl groups had been replaced by the 4-(2,2,6,6-tetramethyl-1-piperidinyloxy) moiety was 13 times more potent as an inhibitor of Torpedo californica acetylcholinesterase than the parent drug. The symmetrical decamethonium (XVI) and hexamethonium (XIV) spin labels were 18 and 1.8 times as active as decamethonium in the same assay system. The substitution of the 4-(2,2,6,6-tetramethyl-1-piperidinyloxy) group for the isopropyl groups of beta-adrenergic blocking drugs dichlorisoproterenol and propranolol, to give spin labels XXI and XXII, caused a 45 and 54% reduction, respectively, in the ability of these compounds to inhibit the isoproterenol-stimulated activity of rat fat cell membranes. Finally, modification of primaquine by the introduction of the 4-(2,2,6,6-tetramethyl-1-piperidinyloxy) substituent into the amino group of the butyl side chain completely abolished the ability of the drug to bind to nuclei acids. These results suggest that the incorporation of the nitroxide group into drug molecules may be a useful approach to the synthesis of more specific spin labels for biological systems, such as egg white avidin, acetylcholinesterase, and the beta-adrenergic receptor.


Adrenergic agents. 3. Synthesis and adrenergic activity of some catecholamine analogs bearing a substituted sulfonyl or sulfonylalkyl group in the meta position.

The m-phenolic group of catecholamine beta-adrenergic agonists may be replaced by various functionalities capable of undergoing H bonding. Considerable latitude in the nature of the OH simulating group is permissible with retention of activity; however, the most extensively studied analogs are ones in which a mobile proton is attached to an O or N atom. In a search for new selective bronchodilators a series of catecholamine analogs bearing a substituted sulfonyl or sulfonylalkyl group in the meta position (i.e., groups in which the mobile H is attached to a C atom) was examined. These compounds were studied for beta-adrenergic agonist activity in vitro by measuring their ability to relax tracheal smooth muscle and to increase the rate of spontaneously beating right atria of guinea pigs. Adrenergic activity was influenced by the nature of the alkylene bridge between the sulfonyl and aromatic groups, branching of the ethanolamine side chain, stereochemistry, and substitution of the sulfonyl and amino groups. Beta-adrenergic blockage was noted for some compounds having the sulfonyl attached directly to the ring. Greatest beta-adrenergic agonist potency and tissue selectivity was observed with a m-MeSO2CH2 substituent. One of these compounds, alpha-[[(1,1-dimethylethyl)amino]methyl]-4-hydroxy-3-[(methylsulfonyl)methyl]benzenemethanol hydrochloride (sulfonterol hydrochloride, USAN), was studied more extensively in animals and is presently being examined for bronchodilator activity in man.


The use of fresh blood in the treatment of critically injured patients.

Initial transfusion needs aremet by type-specific rather than low titer O-negative blood. When the patient's problem approaches the magnitude of exchange transfusion (5 to 10 units) in less than 4 hours, platelet transfusion to treat dilutional thrombocytopenia is administered. Fresh frozen plasma is administered to provide clotting factors. When five units have been exceeded, platelet, pro-thrombin, and partial thromboplastin are measured. A blood clot is checked for clotting, retraction, and lysis. These tests screen platelet quantity and the intrinsic and extrinsic clotting system. Administered blood is warmed in a water bath or heating coil. Blood gas analysis (pH, pO2, and pCO2) is performed every five units to allow for precise administration of bicarbonate. The electrocardiogram is used to monitor potassium and calcium abnormalities. Hyperkalemia is seldom a problem. Hypocalcemia may be present transiently and is treated with calcium choride. Component therapy is the standard recommended practice. Fresh blood is recommended for the patient who has had an acute exchange transfusion and continues to require large quantities of blood. Fresh blood obviates the need for combining components and allows one transfusion unit to address itself to the multiple needs of the patient.


Spontaneous rupture of the kidney secondary to polyarteritis nodosa.

Spontaneous rupture of the kidney occurs rarely. Among the known causes polyarteritis nodosa is uncommon with less than 50 cases reported. Diagnosis is difficult to make with certainty. Our case concerns a 38-year-old man whose symptoms originally simulated acute renal colic. Nephrectomy was done. A brief review of the pertinent literature, diagnosis and management is presented.


The digestive tract of the whiteback griffon vulture and its role in disease transmission among wild ungulates.

The digestive tract of the whiteback vulture (Gyps africanus) is described. Some disease organisms were fed to a captive bird to discover if they could survive passage through the tract, and the role of these scavenging birds in the spread of diseases among wild ungulates is discussed.


Chronic shedding tularemia nephritis in rodents: possible relation to occurrence of Francisella tularensis in lotic waters.

Contamination of streams by Francisella tularensis, a fastidious pathogen, was discovered by Miller in Russia. Subsequently that contamination was found to be the source of extensive human outbreaks, and to occur as well in North America. Circumstantial evidence supports a hypothesis that infected voles are responsible for the contamination, but when freshly isolated F. tularensis palaearctica is inoculated parenterally, only acute illness and death result whereas long-term contamination of streams would seem to demand a more chronic process. Laboratory studies have demonstrated that voles have an apparent predilection to tularemic nephritis when partially immunized before parenteral infection, but also when naive voles are infected orally. Associated chronic bacteriuria would seem to fulfill requirements for protracted contamination of watersheds.


The diagnostic value of sputum culture in acute pneumonia.

In a prospective study of patients with acute pneumonia, the results of bacteriologic analysis of sputum, transtracheal aspirate (TA), and bronchial aspirate (BA) were compared. Streptococcus pneumoniae was grown from all three sources as the predominant organism in 13 of 16 cases; the remaining three patients had nonbacterial lung disease. These data support the traditional concept that culture of the sputum is highly reliable in providing a correct diagnosis in acute pneumonia.


Biochemical evaluation of sympathetic nerve tone in essential hypertension.

The concentration of plasma catecholamines (CA), serum dopamine beta-hydoxylase (DBH) activity and plasma renin activity (PRA) were simultaneously measured in 55 patients with essential hypertension (EH). Further the enzyme activities of CA biosynthesis in human vas deferens excised at elective vasectomy were related with the blood pressure, plasma CA, serum DBH of 57 men at the time of vasectomy. Total plasma CA and norepinephrine (NE) were increased in 28 and 35% of patients with benign EH, respectively. Total plasma CA were also increased in 45% of men with elevated blood pressure prior to vasectomy. Total plasma CA were correlated with diastolic blood pressure in EH (p less than 0.01). Further, in men with normal and raised blood pressure prior to vasectomy, there was a significant correlation of total plasma CA with systolic and diastolic blood pressure (p less than 0.01). Total plasma CA were correlated with PRA in patients with EH (r=0.497, p less than 0.001). Capacity for NE biosynthesis, vas deferens tyrosine hydroxylase (TYH) activity and dopa decarboxylase (DDC) activity were increased in men with raised blood pressure. There was a direct correlation of total plasma CA with the activities of TYH and DDC (r=0.46, and 0.54, p less than 0.005). Increased sympathetic nerve tonicity associated with increased neurotransmitter biosynthesis may be an important factor responsible for blood pressure elevation in men prior to vasectomy and in others with EH. The some patients with EH may have a renin-catecholamine relationship and both pressor systems may be linked to be a pathogenic factor for the elevation of blood pressure.