The effects of cryopreservation on early development and chromosome constitution in Chinese hamster embryos.

The effects of cryopreservation on early embryonic development were investigated in Chinese hamster embryos. Embryos were randomly divided into 3 groups, as follows: the control group, embryos which were simply cultured; the DMSO group, embryos which were exposed to dimethyl sulfoxide (DMSO) and then cultured; the cryopreservation group, embryos which were cryopreserved and then cultured. The percentages of embryos which developed into blastocysts after 40 hours of cultivation were high in all groups. However, there were significant differences in the mean number of blastomeres with lower values after an exposure to DMSO and cryopreservation (73.2 in the control group, 62.0 in the DMSO group, and 40.2 in the cryopreservation group). No significant differences in chromosome abnormality rate were evident and there was no distinct tendency for variation in karyotype among the 3 groups. These results indicate that DMSO adversely affects the division of blastomeres, and that cryopreservation with DMSO as a cryoprotectant might aggravate these adverse effects.


Experimental look at cochlear mechanics.

The mechanisms by which the organ of Corti is stimulated by acoustic stimuli are discussed on the basis of experimental observations. This discussion refers to the resonance theory as well as to the traveling wave (TW) theory. The measurement of the basilar membrane displacements, of the cochlear microphonic (CM) responses to pure tones and impulses, and the recording of the intracochlear acoustic pressure seem to indicate that, at least in the basal part of the cochlea and for frequencies up to the characteristic frequency of a given location, the cochlear responses do not exhibit large phase lags and long delays which characterize the one-dimensional long-wave models (in which a TW transports the energy along the cochlear partition). These experimental observations suggest that the cochlear partition is excited simultaneously as a whole, more or less like a bank of resonators, as proposed a long time ago by Helmholtz.


An investigation of normally hearing subjects with tinnitus.

The hearing sensitivity and psychological profile of 18 young subjects with tinnitus and normal hearing were investigated by pure-tone and high-frequency audiometry, notched-noise tests, auditory-brainstem responses, evoked otoacoustic emissions and Crown-Crisp experiential index. Psychoacoustical and brainstem tests were comparable to those of 19 normally hearing subjects without tinnitus. Otoacoustic emissions were worse in ears of tinnitus subjects. Neurotic personality traits were stronger in the tinnitus subjects. These traits may be secondary to otological dysfunction, or may contribute to complaint behaviour.


Human long-latency potentials evoked by monaural interruptions of a binaural click train: connection to sound lateralization based on interaural intensity differences.

In 9 subjects with normal hearing, monaural offset (MO) responses in the long-latency range were recorded with and without an ongoing sound (click train at a rate of 250/s) at the opposite ear. In the latter case MOs were perceived simply as termination of a sound. In the former case, however, the abrupt transition from binaural to monaural (BM) stimulation was perceived as a shift of the fused image from the center to either side. Therefore, the fairly large difference potential obtained by subtracting the MO response from the BM response was evaluated as the cortical response to stimulation of the sound lateralization mechanism based on interaural intensity differences. These center-to-side responses, which could be characterized by an N1-P2 wave sequence at latencies of 120 and 220 ms, respectively, were compared with the auditory onset responses also recorded from the same subjects by means of a sequential stimulation paradigm. The scalp topography of the N1 components in all these responses recorded simultaneously from frontocentral, parietocentral and two superior temporal electrodes with a neck reference is discussed.


Acoustic pattern recognition and short-term memory in normal adults and young children.

Our experiments were aimed at determining if the delayed matching-to-sample paradigm (DMS) could be used to study short-term acoustic recognition memory in young children and whether or not differences exist between children and adults. Our results indicate that the DMS paradigm can produce reliable data in young children. The decay of acoustic information over time was equivalent in both children and adults, beginning at about 1 s and lasting for longer than 10 s. With 7-element acoustic frequency-pattern sequences, a performance difference between children and adults was observed which appears explicable on the basis of longer memory spans in the adult subjects. When we equated for span length, this effect was no longer apparent.


Aspects of short-term acoustic recognition memory: modality and serial position effects.

Two experiments were performed to study short-term acoustic recognition memory using synthesized binary tone patterns within a three-interval, three-alternative forced choice psychophysical procedure. In Experiment 1, subjects showed as significant performance advantage in processing binary frequency patterns over intensity and duration patterns. In Experiment 2, we found that elements at the beginnings and ends of various length frequency pattern sequences were recognized better than those in the middle of the sequence (primacy and recency effects). Furthermore, we showed that performance on a serial position task may be a useful tool to demonstrate the limited capacity of information storage in acoustic short-term memory. Sensory memory typically has been examined using verbal stimuli and requiring immediate ordered recall. These results demonstrate the utility of studying sensory memory using complex nonverbal stimuli within a forced-choice recognition paradigm.


Catarrh in sheep.

Catarrh or influenza in sheep occupies a unique position in livestock diseases in Australia. The condition, recognised in 1834, was the subject of government enquiries and the passing of special legislation for its control. Within 30 years it had disappeared. The identity of the condition was not determined then nor has it been identified in subsequent years. The purpose of the article is to review what was recorded about the disorder and to speculate on its nature.


[The ultrasonic diagnosis of foreign bodies in the horse].

Ultrasonography in veterinary practice represents a method that nowadays is a approved component of the examination of small and large animals. Although sometimes more difficult than in small animals, ultrasonography can be often useful in horses. In the present report two cases demonstrate the possibility of sonography in the diagnostic of foreign bodies in soft tissues in horses.


[Laboratory diagnosis and differential diagnosis of disseminated intravascular coagulation in the dog].

The laboratory diagnostic possibilities for characterization of disseminated intravascular coagulation (DIC) in dogs are reviewed. A DIC can be demonstrated by means of: 1. Simultaneous consumption of platelets, fibrinogen, coagulation factors and inhibitors of coagulation 2. Increased plasma levels of the specific reaction products fibrin monomers and fibrinopeptides 3. Secondary hyperfibrinolysis, especially an increase in plasma concentrations of fibrin(ogen) degradation products 4. Presence of schistocytes in the blood smear 5. Improvement in the coagulation values during an efficacious anticoagulant therapy 6. Indication of enhanced turnover and formation of microthrombi in different organs by radioisotopically detected coagulation components. Different principles of the laboratory diagnostic procedure in DIC are illustrated by the results of an animal experiment and clinical case reports. Concerning differential diagnosis among other things a deprivation- and dilution effect as well as a disturbance of synthesis have to be considered. One must especially bear in mind that a DIC may also be caused by different coagulator disturbances, e.g. of prothrombin complex synthesis. A DIC can mask such a defect in laboratory diagnostic findings, thereby complicating the diagnosis.


[Determination of the activity of single coagulation factors in clinically healthy swine and cattle].

Special details of animal haemostaseological investigations are insufficiently known as yet. This concerns as well the use of standardized laboratory methods as the differences between species and the normal ranges. Global tests and determinations of activity of single blood clotting factors (II, V, VII - XII, AT III) were carried out on healthy pigs and cattle. Quantitative evaluations were performed by using human or animal reference plasmas. Special attention was paid to the determinations of single blood clotting factors.


[Micromorphological studies of the blood vessels of the dental pulp of small ruminants].

The blood vascular supply of the dental pulp of 15 domestic sheep of varying age and sex was investigated using light and electron microscopy. The pulp vascular system is showing arterioles with a media of varying thickness and with endothelial cells of variable structure. In the transitional zone between crown and root pulp, the arterioles are taking a typical S- or U-shaped course. The capillary network of the crown pulp is denser and more regular than that in the root pulp. In addition to the capillaries lined by a continuous endothelial tube, there may be others with a typically fenestrated endothelial lining. Specialised vascular structures of the peripheral blood vessels, especially arterio-venous anastomoses as described in man, have not been observed in the sheep.


Synthesis and antidepressant activity of some new 8-thiocarbamoyl-7,8-diazabicyclo[4.3.0]non-6-ene derivatives.

Several 8-thiocarbamoyl-7,8-diazabicyclo[4.3.0]non-6-enes were prepared by condensing two alpha,beta-unsaturated ketones (2-benzylidene and 2,6-dibenzylidene cyclohexanones) with hydrazine hydrate and reacting the resulting compounds with various isothiocyanates. The structures of the synthesized compounds were confirmed by spectra (IR, 1H-NMR) and microanalysis; they were tested for antidepressant activity using Porsolt's behavioural despair test.


Effects of the new cognition-enhancing agent nefiracetam in rats with cerebral embolism.

The effects of nefiracetam (DM-9384, CAS 77191-36-7) on the learning behavior and cholinergic and GABAergic neuronal transmitter systems of rats with experimentally-induced cerebral embolism were investigated. Cerebral embolisms were induced in male Wistar rats by injection of 800 microspheres 50 microns in diameter via the left internal carotid artery under 2% halothane anesthesia. Daily oral administration of nefiracetam (30 mg/kg/d) was started 9 days after embolization. Nefiracetam caused significant (p < 0.05) improvement of deficits in the learning of both water maze and passive avoidance tasks beginning 22 days after embolization of the rats. The drug also significantly restored decreases in cortical choline acetyltransferase (p < 0.05) and hippocampal glutamic acid decarboxylase activities (p < 0.01) in the embolized cerebral hemisphere and significantly increased cortical choline acetyltransferase (p < 0.05) and acetylcholinesterase activities (p < 0.05) in the contralateral cerebral hemisphere 21 days after embolization. These results demonstrate that nefiracetam improves cognitive dysfunction in the late phase in embolized rats and suggest that the effect is at least partly due to the increase in glutamic acid decarboxylase, choline acetyltranseferase and acetylcholinesterase activities.


Molecular structure and antiaggregating activity of the potent local anaesthetic (-)-4-[2-hydroxy-3-(N-isopropylamino)-propoxyimino]-cis-carane .

The molecular structure of (-)-4-[-2-hydroxy-3-(N-isopropylamino)- propoxyimino]-cis-carane (C16H30O2N2.HCl), a recently synthesized potent local anaesthetic, including the absolute configuration at 4 chirality centres was determined using X-ray diffraction method. The substance crystallizes in diastereoisomeric form in lowest symmetry (triclinic P1 space group). Determined intermolecular close contacts between chlorine atoms and nitrogen and hydroxyl oxygen are the main determinants of crystal packing. In the crystalline state nitrogen of the isopropylamine group has quaternary coordination. The influence of the title compound on blood platelets aggregation induced by adenosine diphosphate was studied. The results of parallel tests conducted for lidocaine and bupivacaine show that the antiaggregating activity of the title compound is much stronger. This property could be attributed to the monoterpene part of its molecule, in analogy to the observed cyclic adenosine monophosphate inhibitory action of forskolin (diterpene).


Fluorenone and benzophenone 1,4-dihydropyridine derivatives with cardiodepressant activity.

A series of fluorenone and benzophenone 1,4-dihydropyridine derivatives were prepared. The compounds were evaluated for inotropic, chronotropic and calcium antagonist properties.


Biotransformation of nifedipine in rat and dog.

Following oral and/or intraduodenal administration, the biotransformation of 14C-labelled nifedipine (dimethyl 1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-pyridine-3, 5-dicarboxylate, Bay a 1040, Adalat, CAS 21829-25-4) has been reinvestigated in rats and dogs (dose: 5 mg/kg body weight in both species) to complete the metabolic data. Thirteen metabolites were isolated from the perfusate and bile of the isolated perfused rat liver model. Their structures were elucidated by spectroscopic methods (FAB-MS, combined GC/MS, NMR). The analyzed samples were used for the chromatographic (HPLC) comparison with urine and bile from the in vivo studies. The metabolites identified in rat urine (oral dose) account for 47.4% of the dose administered. 82.8% (rat) and 62.8% (dog) of the dose, resp., could be attributed to known structures in urine and bile following intraduodenal administration. Based on the structures identified the following biotransformation steps occurred: dehydrogenation of the 1,4-dihydropyridine system, hydroxylation of the methyl groups at 2- or 6-position followed by glucuronidation or by subsequent oxidation to the carboxylic acid, and oxidative ester cleavage.


Biotransformation and pharmacokinetics of the nitrate trans-2-amino-2-methyl-N-(4-nitroxycyclohexyl)-propionamide in dogs.

The biotransformation and the pharmacokinetic behavior of the organic nitrate trans-2-Amino-2-methyl-N-(4-nitroxycyclohexyl)-propionamide (BM 12.1179, CAS 129795-96-6) were examined in dogs. BM 12.1179 was predominantly eliminated by urinary excretion, and the unchanged molecule prevailed in urine as well as in plasma. By means of various mass spectroscopic methods, the chemical structures of the metabolites were elucidated. As metabolites trans-2-amino-2-methyl-N-(4-hydroxycyclohexyl)-propionamide and trans-2-amino-2-methyl-N-(4-oxocyclohexyl)-propionamide were formed. Urine levels of the main metabolite were determined by high-pressure liquid chromatography; plasma and urine levels of BM 12.1179 were determined by capillary gas chromatography. The absolute bioavailability of BM 12.1179 was 80-100%. The plasma protein binding was about 34% which is high in comparison to other organic nitrates. BM 12.1179 represents a long-acting organic nitrate in that it shows a slow reductive denitration, and a long elimination half-life of about 10 h.


Modulation of receptor-dependent increase of calcium ions in human platelets by taurine.

Taurine (2-aminoethanesulfonic acid, CAS 107-35-7) is present in high concentrations in platelets. It suppresses bronchial responses to platelet-activating factor (PAF) and inhibits aggregation induced by ADP. In the present experiments human platelet calcium responses to PAF were measured by a fluorescent label "Quin-2" method. Preincubation with 0.01 mol/l of taurine decreased effects of PAF by 250 nmol/l if the initial Ca intracellular response (delta Ca2+) to inductor was more than 400 nmol/l. If the initial response to inductor was less than 150 nmol/l, taurine did not affect the response to inductor if PAF effect was in delta Ca2+ range of 150-400 nmol/l. Hence, some effects of taurine may be ascribed to its modulating influence on secondary Ca2+ messenger.


Effects of the new thromboxane A2 antagonist vapiprost on isolated canine blood vessels.

Effects of the new thromboxane A2 antagonist vapiprost (SN-309, GR-32191B, CAS 85505-64-2) on isolated canine blood vessels were investigated. U46619 ((15S)-hydroxy-11a, 9a-(epoxymethano) prosta-5Z, 13E-dienoic acid) 10(-10)-10(-6) mol/l, a thromboxane A2 analogue, produced concentration-dependent contractions of oblong or ring preparations isolated from basilar, coronary, mesenteric and femoral arteries. Vapiprost 10(-8) and 10(-7) mol/l significantly and concentration-dependently shifted the concentration-contraction curves for U46619 of these arteries to the right. The pA2 values were 8.80 +/- 0.09 in basilar arteries, 8.67 +/- 0.12 in coronary arteries, 8.86 +/- 0.05 in mesenteric arteries and 9.01 +/- 0.07 in femoral arteries. On the other hand, oblong or ring preparations of basilar, coronary, mesenteric and femoral arteries showed sustained contractile responses to KCl 3 x 10(-2) mol/l, U46619 10(-7) mol/l or prostaglandin (PG) F2 alpha 10(-5) mol/l. Norepinephrine (NE) 3 x 10(-5) mol/l also produced sustained contractions in mesenteric and femoral arterial preparations, but not in basilar and coronary arterial preparations. Vapiprost 10(-10)-3 x 10(-6) mol/l relaxed these four arterial preparations constricted with U46619 10(-7) mol/l and PGF 2 alpha 10(-5) mol/l in a concentration-dependent fashion, but hardly affected them constricted with KCl 3 x 10(-2) mol/l. NE 3 x 10(-5) mol/l-induced contractures of mesenteric and femoral arterial preparations were not influenced by any concentrations of vapiprost. Results indicate that vapiprost has an antagonistic action on a so-called TP-receptor and/or a vasoconstrictive prostaglandin(s)-receptor and thus produces vasorelaxation.


Evaluation of the local anaesthetic activity of dimetindene maleate by means of laser algesimetry in healthy volunteers.

Dimetindene maleate (DMM, Fenistil, CAS 3614-69-5) a specific H1-receptor antagonist, is therapeutically used for the treatment of respiratory allergies, urticaria, itching dermatoses and generally pruritic sensations occurring with various diseases. As it exhibits local anaesthetic activity in the rabbit cornea and the local anaesthetic activity of a couple of H1-antagonists was found to be linearly correlated to the H1-potency represented by the pA2-values--and dimethindene maleate demonstrates a high pA2-value--it seemed worth investigating the local anaesthetic potency in man making use of an objective and well validated pain model, the Laser algesimetry. The study was carried out with 24 healthy volunteers in a double-blind placebo- and reference-controlled, randomized, cross-over design. Three different medications were applied with occlusive dressing: DMM, lidocaine, and placebo. Selective thermo-noxious stimulation of A-delta- and C-fibers was induced by a CO2-laser. Somato-sensory evoked vertex potentials (SEPs) were simultaneously recorded. Both verum treatments showed a remarkable analgesic potency compared to placebo. Effects were preferably concentrated on the peripheral N1-component of the SEPs. The overall means of the N1-amplitudes were suppressed compared to placebo by both active drugs, with the effects being more pronounced for DMM.


Influence of mofebutazone in comparison to phenylbutazone on the adenosine triphosphate level of polymorphonuclear cells and their migration.

Two pyrazolon derivatives--mofebutazone (CAS 2210-63-1) and phenylbutazone (CAS 50-33-9)--were compared as to their effects on the adenosine triphosphate (ATP) level of polymorphonuclear cells (PMNs) and their response to the migration of these cells. In the range of 10(-8) to 10(-3) mol/l neither mofebutazone nor phenylbutazone significantly changed the ATP level of PMNs. Compared to the untreated PMNs only phenylbutazone reduced the migration of PMNs significantly (chemotactic index (CI) 0.46) at a concentration of 10(-3) mol/l. On the other hand with mofebutazone no statistically significant abnormality on PMN migration was found. Direct statistical comparisons of the migration between specific concentrations of the two pharmaceuticals did not indicate a different migration behavior even at 10(-3) mol/l. These results show that in contrast to the chemical and pharmacological differences of mofebutazone and phenylbutazone their effect on the ATP level and the migration of PMNs is comparable.


[Comparative biological availability of two different ibuprofen granules].

Bioavailability of ibuprofen (CAS 15687-27-1) was investigated in 12 healthy volunteers who received 2 sachets of newly developed effervescent granules (Imbun), each containing 500 mg of ibuprofen lysine salt (corresponding to 292.6 mg of ibuprofen) as the test preparation and 1 sachet of commercially available granules containing 600 mg ibuprofen. Blood samples were withdrawn pre-dose and at 16 occasions until 10 h post dose. Ibuprofen plasma concentrations were assayed by HPLC using a proprietary column-switching technique. Maximum plasma concentrations, Cmax, and times of their occurrence, tmax, were taken from the plasma data directly, areas under the plasma level/time curves, AUC0-10, were calculated using the trapezoidal rule. Pharmacokinetic parameters were checked for significant differences using ANOVA with p = 0.05. When the test preparation was applied maximum ibuprofen levels of 60 +/- 17 micrograms/ml were reached at 27 +/- 17 min p. appl. while Cmax was 52 +/- 12 micrograms/ml at tmax = 94 +/- 27 min after application of the reference preparation. AUC values were 150 +/- 44 microgramsh/ml (test) and 148 +/- 33 microgramsh/ml (reference), respectively. Thus, relative bioavailability of ibuprofen was 101.8 +/- 16.3% (or 104.1 +/- 16.7% when the slight differences in doses were corrected for). Differences in extent of absorption as measured by AUC and Cmax proved to be insignificant whereas differences in absorption rate as measured by tmax were highly significant (p < 0.001).


Dose-proportional plasma levels of the analgesic flupirtine maleate in man. Application of a new HPLC assay.

Single oral doses of the non-opioid, centrally-acting analgesic flupirtine maleate (Katadolon, CAS 75507-68-5) were administered to healthy volunteers and the 2 h plasma levels determined with a new specific HPLC assay. 50, 100, 200, and 300 mg were ingested as the commercial capsules in a double-blind randomized cross-over design with time intervals of at least 6 d. Dose-proportionality was observed for the median 2 h plasma levels which is in agreement with dose-proportionality previously described for multiple-dose studies.


[Individual dosing in methadone substitution therapy. Determination of concentration with high performance liquid chromatography in comparison to immunoassay].

Individual Dosing in Methadone Maintenance Therapy/Plasma level determination by means of high performance liquid chromatography versus immunoassay. Measuring plasma methadone levels during maintenance therapy is a matter of discussion. Yet, there has been surprisingly little interest in integrating therapeutic drug monitoring into methadone maintenance programmes. The reasons for this are practical. To achieve optimal results during methadone maintenance therapy, a plasma level higher than 200 ng/ml is desired at all times during treatment. In the present study, a total number of 124 plasma samples were estimated twice: by means of HPLC and by means of fluorescence polarization immunoassay (Abbott TDx). The coefficient of correlation was 0.96416. We conclude that therapeutic drug monitoring should become routine in methadone treatment to achieve optimum results, especially in patients who complain of withdrawal symptoms and continue high-risk behaviour. The used immunoassay was found to be safe and inexpensive.


Potentially active hypoglycemic agents from N1-nicotinoyl-2-pyrazolin-5-one derivatives and their N1-(oxynicotinoyl) analogues.

Several ethyl 2,3-dioxohexanoate 2-arylhydrazone derivatives were obtained via coupling of the appropriate diazonium chlorides with ethyl butanoylacetate. Acetic acid-mediated cyclization of these products with N1-nicotinoyl and/or N1-(oxynicotinoyl)hydrazine derivatives gave a new series of 4-arylhydrazono-3-(n-propyl)-N1-nicotinoyl-2-pyrazolin-5-one s (Va-h) as well as their N1-(oxynicotinoyl) analogues (VIa-h). The structure of the prepared compounds was confirmed on the basis of elemental and spectral data. The hypoglycemic effect, antibacterial activity and toxicity of these agents were evaluated and discussed.


Studies on the metabolic clearance of ciclotropium to alpha-phenylciclopentylacetic acid using a new enantiospecific metabolite assay.

Ester hydrolysis represents an important biotransformation pathway for various parasympatholytic agents. Cleavage of the ciclotropium ester bond results in the formation of alpha-phenylciclopentylacetic acid (PCA). The relevance of this metabolic route for ciclotropium bromide (HIT-PCE, CAS 85166-20-7) including its stereochemical aspects was studied in a preliminary pharmacokinetic study. An enantiospecific assay for biological material was developed that is based on chiral derivatization of PCA with N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide (EDAC) and the primary amine S-FLOPA, a chiral coupling component for carboxylic acids derived from S-flunoxaprofen, followed by HPLC resolution. R-(--)-Ibuprofen was used as internal standard. From plasma or urine PCA can be extracted into n-hexane/ethanol (9:1) at pH 4 under addition of sodium chloride. Derivatization with EDAC/FLOPA was performed under addition of 1-hydroxybenzotriazole in anhydrous dichloromethane that contained trace amounts of pyridine (ambient temperature; 2 h reaction time). The chromatographic separation was performed on a silica gel stationary phase (Zorbax Sil) using n-hexane-chloroform-ethanol (100:10:1, by vol.) as mobile phase (flow rate, 2 ml/min; fluorescence-detection, 305/355 nm; elution order of the derivatives, (-) before (+)). Limit of quantification was 1.0 ng/ml for plasma and 10 ng/ml for urine. In the pharmacokinetic study in two healthy volunteers who received a single i.v. dose of 10 mg ciclotropium race-mate the PCA concentrations in plasma were below the detection limit, but approx. 1.5% of the administered dose were excreted into urine as the respective glucuronides.(ABSTRACT TRUNCATED AT 250 WORDS)


Dose-response effects of oral loxiglumide on postprandial gall-bladder emptying in man.

The effect of two different single oral doses of loxiglumide (CR 1505, CAS 107097-80-3) on gall-bladder emptying induced by a 550-cal standard mixed meal in 6 healthy volunteers was studied. Following placebo, the maximal gall-bladder emptying occurred about 90 min after the meal (minimal residual gall-bladder volume 27.4% of basal volume). Loxiglumide 400 or 800 mg dose-dependently inhibited the physiologica gall-bladder emptying. Loxiglumide plasma levels dose-dependently increased. The inhibition of gall-bladder emptying and the kinetic of loxiglumide plasma levels were temporally related. The results of the present study confirm that oral loxiglumide is a potent orally active cholecystokinin (CCK) antagonist in man and that CCK is the major physiological mediator of gallbladder emptying in response to meal.


Chronic toxicity study on a new glucan extracted from Candida albicans in rats.

Fifty-two-week oral toxicity of a new glucan (Glucanil, Gluimmun) extracted from Candida albicans ATCC 20955 was investigated in rats. The glucan was orally administered in dose levels up to 200 mg/kg/d and was well tolerated. No deviation from normality was observed in mortality, physical appearance and general behaviour of the treated animals. Food and water consumption and body weight gain of glucan-fed groups did not differ from those of control animals. In these groups no alteration of the weight of the main organs was also observed. Hematology, blood chemistry, urinalysis and autopsy findings were within normal ranges in every group of rats treated. No sex difference was noted. In the 200 mg/kg group soft stools or diarrhoea and cecal enlargement with variable hyperplasia of the colon mucosa were observed. These symptoms are typical of exposure to substances which are absorbed incompletely in the small intestine and subjected to microbial metabolism in the cecum and colon. Diarrhoea, cecal enlargement and mucosal hyperplasia are reversible. The no-effect dose level was estimated to be 100 mg/kg/d under these conditions.


Effects of subinhibitory concentrations of ciclopirox on the adherence of Candida albicans to human buccal and vaginal epithelial cells.

At present, only a limited number of studies of the effects of sub-inhibitory antifungal agents on the adherence of Candida to epithelial (buccal and vaginal) host cells are available. The adherence of Candida albicans to the epithelial cell surface is accepted as an important first step in persistent colonization and in the following symptomatic or asymptomatic infection of mucosal surface. Ciclopirox (ciclopiroxolamine, CAS 29342-05-0) is a substituted pyridone antimycotic drug, unrelated to the imidazole derivatives and its topical application ensures maximum local bioavailability. The present study was done to investigate the effects of sub-inhibitory concentrations of ciclopirox on the adherence of Candida albicans to human buccal and vaginal epithelial cells. The findings on the adherence of different strains of Candida indicate that the drug caused a significant reduction in the mean number of Candida adhering to both buccal and vaginal cells. This reduction was maximal at concentration of 1/2 MIC and still significant at 1/4, 1/8, 1/16 MIC, but with progressive return to mean control values at 1/32 MIC. Ciclopirox acts on fungi by inhibiting the intracellular uptake of essential substrates and ions and this probably acts on the Candida ability to express its adherence mechanisms.


[Dihydroergocristine. A review of pharmacology and toxicology].

A pharmacological and toxicological review of dihydroergocristine (DHEC, CAS 17479-19-5) is reported. Dihydroergocristine exercises a double agonistic/antagonistic activity on dopaminergic and adrenergic receptors; it also shows a non competitive antagonistic effect on serotonin receptors. The central effects of DHEC depend on the initial cerebrovascular resistance. DHEC exercises an inhibiting effect on the anaerobic glycolysis and on aerobic oxidation processes. It increases the cerebral blood flow and the oxygen consumption of the brain. Dihydroergocristine protects the brain against the metabolic effects of ischaemia by acting at a cellular level. In age-related modifications of the cerebral enzymatic antioxidant system DHEC increases the reduced glutathione. DHEC exercises a vasoregulating amphoteric action which depends on the initial tonus: it is hypotensive in hypertensive and normotensive animals but it is hypertensive in hypotensive animals. The results of acute and chronic toxicity in rats, dogs and monkeys, of teratogenesis and fertility in rats and rabbits and of mutagenic tests show that DHEC is a non toxic and well tolerated drug.


[Cerebral actions of dihydroergocristine].

Dihydroergocristine (DEC, CAS 17479-19-5) is a dihydrogenated ergot alkaloid with a potent dopaminergic activity that has been proved both in vitro and in vivo. Apart from its effect on the secretion of pituitary hormones, the following actions have been evidenced. It induces stereotyped behaviour and changes in the sleep-waking cycle, and reduces hypoxia-induced cerebral metabolic changes and emesis. The effect of DHEC on behaviour patterns has been studied in aged male rats in comparison with young animals. The acquisition of the active avoidance response in the shuttle-box test and the retention of the passive avoidance response in a step-through passive avoidance task were facilitated in aged rats by an acute treatment with DHEC. The effect on the acquisition and extinction of the pole-jumping performance after a single injection of DHEC at the beginning of the acquisition session was restricted to the first acquisition trial. A more potent effect on the acquisition of the shuttle-box response and on the retention of passive avoidance reaction was found in animals treated subchronically with DHEC. The latter animals also showed a facilitation of acquisition and an inhibition of extinction of the pole-jumping performance. In other experiments, the repeated administration of DHEC was followed by a decrease in the excessive grooming in aged rats, which is considered a sign of the lack of adaptability of these animals. A facilitation of the compensatory mechanisms in experimental models of vertigo has also been found in animals treated with DHEC.


[The pharmacokinetics of dihydroergocristine after intravenous and oral administration in rats].

The pharmacokinetic properties of dihydroergocristine (DHEC, CAS 17479-19-5) were investigated in rats using a specific radioimmunoassay technique specific for non-metabolized drugs. DHEC, administered intravenously at the dose of 6 mg/kg, showed a plasma profile conforming to an open two-compartment pharmacokinetic model with a long terminal half-life (t1/2 = 13.6 h). DHEC kinetics after oral administration (6 mg/kg) showed two peaks. The first peak (C = 37 micrograms/l) occurred at the first collection point (0.5 h) indicating a quick absorption of the drug. The second peak (C = 34 micrograms/l) occurred at 2 h and may be considered an indication of an enterohepatic cycle. A long terminal half-life (t1/2 = 18.1 h) was observed. An extensive biotransformation of DHEC was indicated by an almost complete absence of unchanged drug in the urine and a high systemic clearance (2.65 l.h-1 x kg-1). A large volume of distribution (52 l.kg-1) was calculated.


[The pharmacokinetics of dihydroergocristine in free-will subjects after oral administration of three formulations].

This paper reports the pharmacokinetics of three dihydroergocristine (DHEC, CAS 17479-19-5) oral formulations in six volunteers. In a randomized crossover trial the volunteers received 6 mg of the drug (1 tablet of 6 mg; 3 ml of drops containing 2 mg/ml; 1 single-dose bottle containing 6 mg); radioimmunoassay was used for the determination of the unchanged drug plasma levels. DHEC shows a plasma profile according to a 3-compartment pharmacokinetic model with a long half-life and high distribution volume. The analysis of AUC0-infinity, Cmax, tmax, and other pharmacokinetic parameters shows that the three formulations investigated are practically bioequivalent.


[Dihydroergocristine in the treatment of organic brain psychosyndrome. Dose-finding study against placebo].

Purpose of this study was to evaluate the activity of dihydroergocristine (DHEC, CAS 17479-19-5) at three different dosages, when administered to aged patients with senile dementia of Alzheimer type. Eighty patients, 48 males and 32 females, aged 55-80 years, affected with senile organic brain syndrome, were admitted to the trial. Clinical evaluation was made by SCAG (Sandoz Clinical Assessment Geriatric Scale). Inclusion criteria considered patients presenting at the basal evaluation a total SCAG score between 60 and 90, with stressed impairment of cognitive function. All the patients were divided in four groups and treated with DHEC 1.5, 3, 6 mg/d or placebo for three months. The evaluation of the total SCAG score demonstrated a significant activity of the drug compared vs placebo, and a dose-related effect. Also for the single clusters it was demonstrated a significant (p < 0.05) dose/effect relation, except for the "affective" one; on the contrary "cognitive functioning" cluster displayed the best benefit. The drug was very well tolerated, as only some cases of dyspepsia, mild gastralgia and nausea were reported in some patients.


[The effect of dihydroergocristine on cognitive functions and sleep in elderly subjects].

The aim of this study was to assess the effect induced by the dopamine agonist dihydroergocristine (DHEC, CAS 17479-19-5), whose memory-improving activity is well-known, on sleep pattern and cognitive function, and the possible relationship between them. Ten elderly volunteers were included in the study. Selected subjects had to be neither demented nor depressed, according to neuropsychodiagnostic criteria (SCAG < 30, Hachinski dementia score < or = 15, Hachinski ischemic score < 6, HRSD < or = 22). All subjects underwent a nightly polysomnographic evaluation during placebo, after single and long-term once-daily 6 mg DHEC administration. Cognitive function and attention were also assessed by the Randt memory test and WAIS digit-symbol subtest. DHEC caused a marked and significant increase in the acquisition subitem, and memory improvement was documented during DHEC treatment. A significant direct relationship between the effect of DHEC on REM sleep and memory test was also evidenced. Our results confirmed the role of REM sleep in the restoration of cognitive function.


[Controlled study of the effect of dihydroergocristine on organic brain psychosyndrome].

The aim of this study was to verify long-term therapeutic efficacy and tolerance of dihydroergocristine (DHEC, CAS 17479-19-5) in a double blind placebo controlled study, in elderly patients with psychosyndrome characterized by memory and behaviour impairment. Two hundred patients, aged more than 65 years, were randomly divided into two groups of one hundred each. The first group received one 6-mg DHEC tablet daily for four months and the other group received placebo. The evaluation parameter for efficacy was the neuropsychological test SCAG (Scale of Clinical Assessment for Geriatrics), administered before and after 30, 60 and 120 days. The results showed a significant difference between DHEC and placebo with regard to total and partial scores of SCAG as well as to single items (mental alertness, recent memory, disorientation, anxiety, mood depression, emotional lability, motivation, uncooperativeness, fatigue, headache, tinnitus). After as few as thirty days of DHEC treatment the severity of mental and psychological symptoms was markedly decreased (p vs placebo < 0.01), as documented by significant positive changes of SCAG items. The four-month double blind period was followed by a two-month single blind period, during which patients of both groups received placebo. At the end of these two months, SCAG total score was unfavourably increased in patients previously administered DHEC, although scores were still significantly lower both versus baseline and versus previous placebo patients. Safety was good (placebo: one case of diarrhea; DHEC: one case of gastralgia and dizziness). Nine patients dropped out for reasons unrelated to treatment.(ABSTRACT TRUNCATED AT 250 WORDS)


[Dihydroergocristine in organic brain psychosyndrome. Multicenter placebo-controlled clinical double-blind study in 240 patients].

The aim of this 3-month study was to assess the activity of dihydroergocristine (DHEC, CAS 17479-15-5) on organic brain syndrome. DHEC is an ergot alkaloid derivative with a dopaminergic activity on the central nervous system (CNS). It improves cerebral metabolism and increases the bioelectric potential in the cerebral cortex. The randomized double-blind trial versus placebo involved 240 outpatients (138 females and 102 males, mean age 68 years) recruited in 6 hospitals. Subjects with Hachinski Ischemic Score > 6 and Mini Mental State < 22 were excluded. Patients were randomly divided into 4 groups of 60 subjects each to receive either one 6-mg DHEC oral vial or placebo vial, or one 6-mg DHEC tablet or placebo tablet once daily for 3 months. Neuropsychological tests were performed at baseline, and then after 45 and 90 days of treatment. The statistical analysis of results showed a significant difference (p < 0.01) between DHEC and placebo groups with regard to the following tests: "Scale of Clinical Assessment for Geriatrics (SCAG), Digit Symbol, Digit Span, Toulouse-Pieron, Hamilton Depression Rating Scale and Rey's Words". The amelioration of clinical symptoms pointed out the equivalence of DHEC oral vials and tablets. The drug was well tolerated. It is concluded that DHEC is an effective and safe drug in the treatment or organic brain syndrome.


[One-year therapy with dihydroergocristine for treatment of impaired alertness and memory in elderly patients. Placebo-controlled multicenter study].

This double-blind study of dihydroergocristine (DHEC, CAS 17479-19-5) versus placebo was performed in 240 elderly patients affected by chronic cerebrovascular disease or organic brain syndrome. The therapy was carried on for one year. Results pointed out a decrease of SCAG total score and a significant improvement of the target items "confusion, mental alertness and memory performance" after DHEC versus placebo. Furthermore the data show that DHEC maintained its activity throughout the 12-month trial period. Very few and mild side-effects were reported for both groups, thus confirming the well known good safety of the compound. Based on results of this 1-year investigation, it is concluded that DHEC treatment should not be abruptly interrupted, but continued for as long as possible.


[Epidemiologic study on the effectiveness and safety of dihydroergocristine in impaired memory and behavioral functions in aged humans].

Aim of the study was to assess the activity of dihydroergocristine (DHEC, CAS 17479-19-5) in aged patients with impaired cognitive function. Twenty-five university hospital centres and 250 physicians participated in the study. 2,600 patients (1,104 males and 1,496 females, age range 50-80 years) were admitted to the study. Each patient was administered 6 mg/d DHEC for 120 days. Clinical evaluation was made through the SCAG Rating Scale registered at basal time, after 60 and 120 days. Responsivity to treatment was considered high when the final score was reduced by 30% and none if less than 10%. Analysis of results demonstrated that at the end of the study responsivity was high in 73% of cases, moderate in 20.4% and absent in 6.5%. Tolerability was very good as side effects were reported only in 3.16% of patients. Most frequent side effects were: nausea (1.23%), gastralgia (1.11%), headache (0.29%), hypotension (0.12%), vertigo (0.12%) and rash (0.08%). Drop-outs for gastralgia were reported only in 0.53% of the patients.


Preservice training to meet the needs of people from diverse cultural backgrounds.

The provision of speech-language pathology and audiology services to persons from culturally and linguistically diverse populations is changing. Researchers have indicated that many current ASHA certified speech-language pathologists and audiologists do not perceive themselves as competent to provide services to individuals from culturally and linguistically diverse backgrounds due to the paucity of this information during their professional education (Campbell, 1986; Shewan & Malm, 1989; Snope, 1982). ASHA has attempted to meet the needs of individuals from culturally and linguistically diverse backgrounds who are communicatively impaired and students and practitioners through the latest revisions of the requirements for the Certificates of clinical Competence and through ESB accreditation requirements for university training programs. This article discussed several important needs associated with university training programs for speech-language pathologists and audiologists that must be considered as the professions respond to the needs of specific service populations.


Devices for the hearing impaired.

Hearing loss can result in significant communicative and social dysfunction. Various methods of sound amplification are available for the hearing impaired. Hearing aids are becoming more technologically sophisticated, more cosmetically appealing and more commonly used. The choice of hearing aid must be individualized and depends on several factors, including the type of hearing loss, the cost of the device, the patient's work environment, motivation and vanity, and the degree of difficulty in using the hearing aid. Devices are also available to help hearing-impaired persons in specific situations where hearing aids may not be necessary. The cochlear implant is a relatively new device for use in the profoundly hearing impaired.


Thermal desorption-gas chromatography for the determination of benzene, aniline, nitrobenzene and chlorobenzene in workplace air.

Sampling on Tenax TA of different mesh sizes followed by thermal desorption and gas chromatography was evaluated as a simple method for the determination of benzene, aniline, nitrobenzene and chlorobenzene in the workplace air. An alternative sampling technique in place of pump sampling was developed. Quantitative recoveries were obtained in the mass range 0.04-10 micrograms. It was found that air humidity had no effect on recovery. The charged tubes can be stored at room temperature for 5 days with no change in recovery. The particle size of Tenax TA has no significant effect on adsorption and desorption.


Chronic fatigue syndrome.

A 36-yr-old white female presented with severe fatigue and symptoms consistent with immune deficiency, but was later found to be suffering from chronic fatigue syndrome. This article discusses the diagnostic criteria for this condition. Chiropractic manipulation afforded relief of some symptoms for this patient.


Neuropharmacological study of aged MAM-treated rats.

After evaluation of activity in an open field, norepinephrine (NE), serotonin (5HT), 5-hydroxyindolacetic acid (5HIAA), homovanillic acid (HVA), and choline acetyltransferase (CAT) were investigated in cortex of 26-month-old rats poisoned with methylazoxymethanol (MAM) as compared to control rats of the same age. NE and 5HT concentrations showed a marked increase, but levels were normal when expressed as total content, just as in MAM-exposed young adults. Concentrations of 5HIAA were also increased but to a lesser extent than 5 HT. Aged MAM rats did not show any modification of spontaneous activity although hyperactivity is characteristic of young adults exposed to MAM. Together with this behavioral observation, a significant decrease in total HVA content was measured. Because HVA levels seem correlated with activity in MAM-exposed rats, we speculate that the behavioral abnormality recovers in old age. Total CAT activity was also reduced. These results indicate that the neurochemical pattern of young adult MAM-poisoned rats is conserved in aged rats except for some changes in the dopaminergic and cholinergic systems.


Postpartum hemolytic uremic syndrome associated with antiphospholipid antibodies. A case report and review of the literature.

Postpartum hemolytic uremic syndrome (HUS) is described in a woman with a history of spontaneous abortions and both circulating lupus anticoagulant and anticardiolipin antibody (ACA). After termination of her pregnancy because of severe preeclampsia, ACA blood levels increased simultaneously with the onset of a microangiopathic process associated with severe hypertension and renal failure. Plasma exchange resulted in a rapid decline in ACA levels and immediate improvement in her clinical condition. This case strongly suggests an important causal relationship between ACA and postpartum HUS. The possible mechanisms of ACA-related postpartum HUS and the potential role of plasmapheresis in its treatment are reviewed and discussed.


Occupational cancer in Canada: what do we know?

To examine the reporting of cases of occupational cancer in Canada in order to determine reporting requirements, the availability of data, the characteristics of reported cancers and the completeness of reporting. Descriptive epidemiologic study based on data requested from workers' compensation boards (WCBs) and cancer registries in each province and territory from 1980 to 1989. The number of claims accepted and rejected by the WCBs; year of claim, cancer site, sex of claimant, age of claimant at diagnosis, occupation, industry, exposure agent and reasons for rejection of claims; and new primary cancers according to site, age and sex. Reporting of occupational cancer by physicians is required in Alberta, Saskatchewan and Newfoundland. Only British Columbia, Saskatchewan and Ontario were able to provide all the requested information about the claims. Of the 1026 claims in these three provinces almost all were by men, and about two-thirds were for cancers of the respiratory tract. Asbestos was listed as the etiologic agent in more than one-third of the cases. A comparison of the proportion of incident cancers accepted as occupational by the WCBs with the estimated proportion of cancers in the general population attributable to occupation (based on population-attributable risk percentages from epidemiologic data) suggests that less than 10% of occupational cancers [corrected] are compensated. The main source of the deficit is underreporting to WCBs rather than rejection of claims. The availability of data about occupational cancers in Canada is inconsistent from jurisdiction to jurisdiction, and reporting is incomplete. An active disease surveillance system and additional education of physicians and workers about work-related illnesses may be required to improve reporting.


Race and ethnicity in housing: turnover in New York City, 1978-1987.

This study examines the patterns and predictors of housing turnovers among non-Hispanic whites, non-Hispanic blacks, Puerto Ricans, and other Hispanics in New York City during 1978-1987 to assess whether access to housing is distributed differentially by race and ethnicity. The data are taken from the triennial New York City Housing and Vacancy Survey. After controlling for household preferences, purchasing power, and quality characteristics of the housing unit, multinomial logistic regression results show the most consistent and significant predictors of turnover to be geographic and market-sector attributes. The findings suggest the presence of structural constraints in the housing market which effectively channel racial/ethnic groups to separate neighborhoods. The overall results are reminiscent of early studies of neighborhood transition by Duncan and Duncan (1957) and Taeuber and Taeuber (1965), and show that little progress has been made toward achieving equality in housing or informal social contact between racial/ethnic groups.


Serine incorporation into phosphatidylserine in hypoxic rat brain cortex.

The effect of hypoxia on the incorporation of [14C]serine into serine glycerophospholipids was investigated in rat brain cortex. Brain slices were incubated, in the presence of the labeled precursor, in Krebs-Henseleit Ringer bicarbonate or Krebs Ringer phosphate, and hypoxia was induced by bubbling nitrogen in the medium. The lowering of oxygen caused an increase of the incorporation of the base into phosphatidylserine in slices incubated in both media, although the effect was greater in Krebs Ringer phosphate. Such an effect was also observed in the homogenate subjected to N2-treatment, with an increase in the incorporation similar to that obtained in slices incubated in Krebs-Henseleit Ringer bicarbonate. Phosphatidylserine is synthesized in mammalian tissues by a "base-exchange" enzyme, strictly Ca2+ dependent, and, moreover, is necessary for protein kinase C activity. We postulate that the increased synthesis of phosphatidylserine might affect signal transduction mechanisms and participate in the modification of lipid metabolism observed in hypoxia and/or ischemia.


Eicosanoid formation in the rat cerebral cortex. Contribution of neurons and glia.

Despite the extensive literature on brain eicosanoids, no information is available on the cellular source of individual compounds in the mature organ and the relative contribution of different cell types to the total synthetic product. To address this problem, neurons and glia were isolated from the cerebral cortex of the adult rat by a process comprising, in order, trypsinization, selective sieving, differential centrifugation, and density gradient centrifugation. Enrichment of cells in the appropriate fractions was verified by morphological, immunocytochemical, and biochemical criteria. Both neuron- and glia-rich fractions retained synthetic activity throughout the period of incubation (max. 60 min). Among the eicosanoids examined, prostaglandin (PG) E2 was the predominant compound, followed by leukotriene (LT) E4 and thromboxane (TX) B2, whereas LTC4 occurred in minimal amounts. Although the rank order of eicosanoids did not vary with the cell type, absolute values of PGE2 and TXB2 were greater with neurons. PGE2 synthesis was increased by supplementation of the medium with arachidonic acid (2.6 microM), whereas indomethacin (5.6 microM) had the opposite effect. Conversely, LT synthesis was not altered by arachidonic acid and was only marginally reduced by the 5-lipoxygenase inhibitor, U-60,257 (10 microM). Several agonists (12-O-tetradecanoyl-phorbol-13-acetate, TPA; Ca ionophore A23187; platelet-activating factor; endotoxin; recombinant IL-1) were tested on both neuron- and glia-rich fractions but none of them had an effect. We conclude that freshly isolated neurons and glia are viable insofar as the basal rate of eicosanoid synthesis is concerned. No qualitative difference was noted between the two cell types in the spectrum of products formed and the spectrum itself accorded with early data on the biosynthetic activity of the intact tissue in vivo. Our isolation procedure appears useful for the analysis of the cellular source of eicosanoids under resting conditions, although it cannot be applied to the study of the site and mode of action of activators.


Regional mRNA changes in brain stem motor neurons from patients with amyotrophic lateral sclerosis.

An antisense oligonucleotide (54 mer) from the mRNA to the midsize neurofilament protein (NFM) was labeled with 35S on the 3' end and purified by polyacrylamide gel electrophoresis (PAGE). In situ hybridization was performed on sections from medulla oblongata of patients with amyotrophic lateral sclerosis (ALS). The slides were dipped in photographic emulsion, developed, and stained. Neurons from both nucleus hypoglossus and nucleus ambiguous showed a marked reduction of silver grains when compared to normal. This indicates a reduction of mRNA, which may precede the reduction of ribosomal RNA and the changes in neurofilament proteins that have been described by several investigators in ALS. It does not settle the question of whether the reduction of mRNA is owing to reduced transcription or increased decay of mRNA.


Diabetes-induced alterations of central nervous system G proteins. ADP-ribosylation, immunoreactivity, and gene-expression studies in rat striatum.

Previous studies from our laboratory have suggested that diabetes-associated central nervous system abnormalities are characterized by progressive alterations of neurotransmitters and of transductional Gi/Go proteins. In this study, we have further characterized these abnormalities in the striatum of alloxan-diabetic rats by means of adenosine 5'-diphosphate (ADP)-ribosylation, and Western and Northern blotting techniques. Fourteen weeks after diabetes induction, pertussis-toxin (PTX) catalyzed ADP-ribosylation of Gi/Go proteins was markedly reduced in diabetic animals, as shown by a clear decrease of 32P-ADPribose incorporation into G protein alpha subunits. In agreement with our previous pharmacological studies that showed a reduction of Gi-mediated modulation of adenylate cyclase activity only at this stage of diabetes, no changes in PTX-mediated ADP-ribosylation were observed earlier (5-wk diabetes). Immunoblotting studies performed by using antibodies selectively raised against Gi-2, Go, and Gs proteins did not reveal any differences between control and diabetic animals at any stage of diabetes. Similarly, the mRNAs corresponding to the alpha subunits of Gi-2, Go, and Gs proteins did not show any marked changes in chronic diabetic rats with respect to control animals. It is therefore concluded that diabetes is associated with development of a time-related alteration of cerebral Gi/Go proteins and that this defect is not owing to gross changes in either content of G proteins or mRNA level, but probably reflects modifications of G protein's structure or physiological status affecting the coupling with membrane effector systems and the sensitivity to PTX.


[Tumor-biologic and epidemiologic aspects of laryngeal cancers in women before and after menopause].

44 women with laryngeal cancer were treated between 1961 and 1991 in the ENT clinic of the university of Rostock. 7 patients were found in the phase of fertility, 12 patients within the climacteric and 25 patients in the senium. Half of the patients before menopause and 2/3 of the patients after menopause were smokers. Only one of the women at the fertile age had a laryngological history lasting 1 year before the onset of the cancer illness but half of the patients after menopause revealed such an anamnesis. Laryngological symptoms that existed over a period of one year or more began before the onset of the climacteric phase or clearly in the senium phase. These points in time corresponded to phases of relative or absolute decrease of oestrogens from an endocrinological view. The mean controlled survival time of the patients decreased clearly with increasing age. Furthermore, in the case of the patients with over one year's laryngeal anamnesis the survival time was longer than for patients without anamnesis, at least for patients in the phase of the senium. Several parameters of tumour biology, tumour dynamics and gynaecological history were examined by the authors. A trend indicating an increase of glottic localisation after the onset of the climacteric phase and increase of keratinised carcinomas in the phase of senium was apparent. No other clear differences amongst the patients of various groups could be observed.


Urinary ortho-cresol concentrations as an indicator of toluene inhalation in glue-sniffers.

In a Japanese study of glue-sniffers, urinary ortho-cresol and expired air toluene concentrations were determined by gas chromatography, and urinary hippuric acid concentrations by high performance liquid chromatography. There were significant differences among three sample groups (30 male "glue-sniffers", 13 "non-glue-sniffers" and 32 industrial workers) in their expired air toluene, urinary hippuric acid and ortho-cresol concentrations. Moreover, there was a better correlation between expired air toluene and urinary ortho-cresol concentrations than between toluene and urinary ortho-cresol concentrations than between toluene and hippuric acid. These results suggest that urinary ortho-cresol is a good indicator of toluene inhalation in glue-sniffers.


[Importance of whole body skeletal scintigraphy within the scope of staging of neoplasms in the ENT area].

Concerning malignant tumours of the oral cavity, pharynx and larynx, bone metastases are in general rarely seen. For the specification to which patients the whole body bone scintigraphy as detection method should be applied, the findings of 370 patients were analysed retrospectively. In respect of primary staging, bone metastases could be found by scintigraphy in only 1.4% of the patients. On the other hand, there was a detection rate of 12% during the further course of the disease, especially in case of clinical symptoms pointing at spreading metastases or in tumour recurrences. Nevertheless, positive scan findings which were not due to metastases could be found in both groups with equal frequency (12 and 13%, respectively). Therefore the routine performance of whole body bone scintigraphy as a screening method does not seem to be useful in the primary staging of cancer of the mouth, pharynx and larynx. Contrary to this, in the follow-up of these tumours bone scanning proves to be a valuable and sensitive method for detecting skeletal metastases.


[Clinical relevance of malignant lateral branchial cyst].

We analyzed 7 patients with so called "maligne lateral cervical cysts" regarding the controversies in the literature. Primary tumors of oropharyngeal sites were discovered in all these cases of "branchiogenic carcinoma" rising the final diagnosis of cystic metastases. Diagnostic tonsillectomy is supposed to be important to solve this problem of differential diagnosis. The issue of malignant transformation in cysts of branchial cleft origin has to be recognized as being an oncological artifact. We argue that the "maligne lateral cervical cyst" does'nt exist as a proper entity. In analogy to the principles of the treatment of oropharyngeal cancer ipsilateral neck dissection and wide local excision of the cyst followed by radiation therapy is the suggested plan of therapeutic management. Search for a possible unknown primary tumor within the oropharynx must be continued over years.


[Mechanics and function of the middle ear. 2: Hearing physiologic comments on middle ear surgery].

The reconstruction of the destroyed ossicular chain has the purpose to re-establish an unhindered sound reception and transmission. With respect to the hydraulic factor, the reconstructed chain should be attached to a large effective area of the drum membrane, ideally to the malleus handle. The sensitivity is furthermore diminished in a linear relationship with increasing mass and stiffness. Therefore, cartilage cannot represent an acoustically ideal material for a drum membrane replacement. The reconstructed chain must vibrate without restraint for an unhindered transmission. Furthermore, the interposed prosthesis must be secured firmly to the remnants of the ossicular chain; the reconstructed chain must vibrate like one solid body. A loose contact attenuates the transmission and might result in a dislocation of the prosthesis with excessive ambient air pressure induced displacements of the drum membrane. A solid anchoring might be created by glueing, bony adhesion, special design of the prosthesis or with a wire connection. With unfavorable middle-ear conditions, the piston-like vibrational mode of the footplate has to be met with a direct driving of the stapes by a T-like prosthesis in the extension of the stapedial's vertical (high) axis. Ineffective rocking movements of the footplate are thus reduced. The almost perfect hearing result of the stapesplasty demonstrates that the impedance-matching middle-ear function is determined by the area ratio between the drum membrane and the width of the cochlear scala. Both components are not altered by the operation.(ABSTRACT TRUNCATED AT 250 WORDS)


[The effect of systematic change in middle ear pressure on transitorily evoked otoacoustic emissions--a pressure chamber study].

Otoacoustic emission power spectrum and amplitude are influenced by the middle ear transmission mechanism. In this study, the influence of progressive increase in atmospheric pressure on the frequency and amplitude of transiently evoked otoacoustic emissions (TEOAEs) was determined in normally hearing humans. For testing, subjects were seated in a pressure chamber. Transiently evoked otoacoustic emissions were tested in 20 ears of 20 subjects using of 80 microseconds unfiltered click and tone bursts duration at 0.5, 1, 2, 3, and 4 kHz presented at 40 dBnHL. Ambient air pressure was increased from 0 kPa up to 8 kPa in 2-kPa steps. In spite of large interindividual differences, the results demonstrate that the changes that occur in TEOAEs with variations in ambient air pressure are frequency specific. Amplitude and reproducibility of high-frequency TEOAEs are less influenced by middle ear pressure changes than are the amplitude and reproducibility of low- and middle-frequency TEOAEs. Results have implications for clinical and research applications of TEOAE measurements in that middle-ear and inner-ear effects on OAEs can be differentiated.


[Examination of 1,300 children for incidence and therapy of hearing disorders in pediatric speech disorders].

This study presents the results on 1305 children with speech disorders. The examination includes ENT-inspection, audiometry, speech-evaluations and if required, psychological tests. In 48% we found hearing losses, most frequently in the age up to four years. In 95% hearing losses were fluctuating about 20 decibels, caused by malfunction of the tube or by adenoids, not even in autumn and winter, but also all the year. In this case, fluctuating hearing function reduces the total hearing input over the year. In only 5% we found cochlear hearing loss. In hearing impaired children speech development was significantly more depressed in all dimensions in comparison to normal hearing children. This study does impressive demonstrate the necessity of follow-up microscopic evaluations of the tympanic membrane and audiometry as well as the consequence operative therapy including adenoidectomy and insertion of ventilation tubes. With this concept, only 37% of the children required speech therapy.


[Chronic otitis externa from the dermatologic viewpoint].

Chronic external otitis may be divided into several diagnostic categories. Disposition for psoriasis, seborrhoeic and atopic eczema are main endogenous reasons. Exogenous pathogens for external otitis are microbes and allergens. There are numerous interrelations by coincidence of dispositional diseases, e.g. psoriasis and atopic eczema and by combination of exogenous and endogenous pathogens. This holds good for the yeast Pityrosporum ovale vs. orbiculare in seborrhoeic eczema and for the susceptibility to contact (type IV) and respiratory (type I) allergy in atopic individuals as well. Mycotic and bacterial, especially gram negative external otitis are linked to predisposing factors like eczema, long-term microbicidal therapy, hot and humid environment. Contact allergic external otitis may occur during long lasting local therapy with various substances including vehicles, the most common allergen being neomycin. Mucosal allergic reactions (Type I) in the upper respiratory tract may impair ventilation of the Eustachian tube and middle ear and therefore epithelial migration, as a drainage mechanism of the auditory canal. Examination should include functional assessment of the Eustachian tube and middle ear and allergy testing (patch, prick test). Preparations for local therapy should contain a limited number of constituents and avoid common allergens. Surgical procedures to reestablish ventilation of the middle ear are also a therapy for chronic external otitis.


[Chronic recurrent parotitis in childhood].

Juvenile recurrent parotitis (j.r.p.) is distinguished from the adult form by the course of the disease, therapeutic considerations and prognosis. Children suffering from j.r.p. are between 2 and 15 years of age; the male: female ratio is 1.5:1. In the present paper the author describes the different pathogenic theories of j.r.p. in accordance with the relevant literature. Besides malformation of the glandular duct like stenosis and ectasis, functional factors like the character of salivary secretion are suspected as being responsible for the disease. Other authors assume that a viral genesis, allergic factors, a physiological immaturity of the immune response, or family history may be the causes. In the evaluation of children with j.r.p. the patients' history with recurrent swelling episodes of the parotid gland(s) followed by quiescent periods is indicative. Further procedures like ultrasonography, sialography and MRI are discussed according to their diagnostic value. Therapeutic possibilities include antibiotics in the acute stage of the disease as well as parotidectomy in severe cases. Radiotherapy cannot be recommended because of its side effects (facial dysplasia, tumour induction). In most cases, the disease ends at puberty.


Can ambulance personnel intubate?

To assess the performance of intubation skills by advanced trained ambulance personnel, a prospective study was carried out of the intubation of cardiac arrest victims by ambulance personnel in the field. Twenty-eight ambulance personnel attempted the intubation of 87 patients over 2 years. Eighty-five patients were initially successfully intubated, one endotracheal tube became displaced and cuff leakage occurred on three occasions. This was treated appropriately in each instance. Ambulance personnel can perform the skills of intubation successfully in out-of-hospital cardiac arrest victims.


Audit of unexpected return visits to an accident and emergency department.

Unscheduled re-attendances of patients to the A&E Department were examined over 50 days. A re-attendance rate of 1.9 per 100 new patients was found. Of 102 return visits, only 35 resulted in no change in the diagnosis or treatment. Common faults in the initial consultation were failure to explain the condition and prognosis adequately and failure to provide adequate analgesia. Review of patients reattending unexpectedly by a more senior member of staff is a means of identifying faults in management and advising and educating junior staff.


Causes of fatal childhood accidents in North Staffordshire, 1980-1989.

Sixty-nine children aged under 15 years were identified from coroners' records as having died as a result of an accident between 1980 and 1989. Road traffic accidents (RTAs) accounted for the majority of cases (n = 38; 55% of total) and in almost all of these, the unsafe behaviour of the child was considered to be at fault. Most fatal accidents occurred between 15.00 and 21.00 hrs and within 2 km of the child's home; the majority of children killed were not supervised by an adult at the time of the accident. Considerable variation in mortality within the district was observed with several areas having a rate significantly higher than the district as a whole. Head injury was the most commonly recorded cause of death (n = 37, 53%) confirming the importance of head injury as a cause of childhood mortality. Road safety educational and engineering measures as well as adequate adult supervision and awareness could have prevented the vast majority of these accidental deaths. Coroners records are a vital and often poorly utilized source of locally relevant information regarding childhood accidents which should be of use to all interested agencies including child accident prevention groups.


Case report. Self-induced grand mal epilepsy.

A case of a male patient who accidentally induced a grand mal seizure with a home-made electronics device. Other comparative cases are described.


Case report. Bee sting brachial block.

A case of brachial plexus block is presented, following a bee sting in the posterior triangle of the neck. The onset of neurological symptoms was rapid as was their subsequent resolution. Delayed peripheral neurological symptoms believed to have an immunological basis have been reported in response to stings from bees and other Hymenoptera both in the central and peripheral nervous systems (Goldstein et al., 1960; Means et al., 1973; Bachman et al., 1982; Weatherall et al., 1987; Van Antwerpen et al., 1988), but to the authors' knowledge no similar case of immediate peripheral block has been reported.


The MiniCAP III CO2 Detector: assessment of a device to distinguish oesophageal from tracheal intubation.

A new portable infra-red CO2 detector was assessed in 50 intubated patients. This device was 100% accurate in distinguishing between tracheal and oesophageal intubation when used by nursing and paramedic personnel.


Synthesis of 7-oxo-7H-benzo[e]perimidine-4-carboxamides as potential antitumor drugs.

A series of 7-oxo-7H-benzo[e]perimidine-4-carboxamides (4a-f) was synthetized from the corresponding acid (3) and the suitable amines by the "mixed anhydride" method. The amide derivatives were tested for antitumor activity against P 388 leukemia "in vivo". Only the N-[2-(diethylamino)ethyl]-7-oxo-7H-benzo[e]perimidine-4-carboxa mid e (4b) shows borderline antineoplastic activity.


Synthesis and antimicrobial activity of some pyrrole derivatives. V: 5-Aryl-3-ethoxycarbonyl-2-(4-substituted piperazino)pyrrole derivatives.

The synthesis of new 5-aryl-3-ethoxycarbonyl-2-piperazinopyrrole derivatives is reported. The new compounds were tested in vitro for their antimicrobial activity. Compound 11 was the most active against the Gram-positive microorganisms.


Relationship of utero- and fetoplacental blood flow velocity wave forms with pathomorphological placental findings.

Pulsed Doppler examinations were performed in 143 risk pregnancies. The resistance index (RI) values of the uteroplacental vessels and umbilical artery on the last examination before delivery were correlated to specific patterns of morphological placental findings. The sensitivity and specificity of Doppler blood flow velocity wave forms to predict placental disease as well as the significant relationships were calculated. Impaired uteroplacental perfusion is correlated with: disturbances in growth, such as reduced weight and reduced basal area (p < 0.005, p < 0.05); disturbances in villous maturation, such as prematurity or a reduction in intermediate sized villi (p < 0.05, p < 0.01), and circulation disorders, such as acute or chronic infarcts (p < 0.05), villous fibrosis (p < 0.005) or microfibrin deposits (p < 0.05). Villous immaturity was not correlated to either pathological utero- or fetoplacental blood flow. Except for acute infarcts, all these findings as well as endangiopathy of truncal arteries are also combined with high RI values in umbilical arteries (p < 0.005) possibly reflecting the 'down-stream impedance' of the fetoplacental circulation.


Relief of presumed compression in oligohydramnios: amnioinfusion does not affect umbilical artery Doppler waveforms.

The suggestion that amnioinfusion improves umbilical artery Doppler indices of downstream resistance in oligohydramnios by relieving cord compression was investigated by obtaining waveforms before and immediately after amnioinfusion in 16 pregnancies with severe oligohydramnios. There was no significant difference in the change in umbilical artery pulsatility index (PI) between 11 pregnancies in which amniotic fluid volume was restored (mean delta PI = -0.07, 95% confidence interval -0.17 to +0.07), and 5 pregnancies in which immediate vaginal leakage of infused fluid prevented restitution of amniotic fluid volume. Fetal heart rate did not change significantly in either group. End-diastolic frequencies did not return with restitution of amniotic fluid volume in the 2 pregnancies in which they were absent before infusion (absent in 1, reverse in 1). This study suggests that restitution of amniotic fluid volume in human pregnancies complicated by severe oligohydramnios does not acutely alter the umbilical artery PI.


Prenatal diagnosis and obstetrical management of May-Hegglin anomaly: a case report.

A case of May-Hegglin anomaly, a rare autosomal dominant thrombocytopenia, is reported. This disorder is characterized by giant platelets, basophilic inclusion bodies within the cytoplasm of granulocytes and an occasional bleeding tendency. This bleeding tendency depends on the platelet count. The fetuses of such patients run the risk of intracranial hemorrhage in utero and during the early neonatal period following vaginal delivery. Prenatal diagnosis of this disorder has not yet been reported. We describe a case of this disorder, diagnosed in pregnancy, which, following prenatal diagnosis of mild thrombocytopenia in the fetus and confirmation by cordocentesis, could successfully undergo a vaginal delivery.


Detection of 47,XYY trophoblast fetal cells in maternal blood by fluorescence in situ hybridization after using immunomagnetic lymphocyte depletion and flow cytometry sorting.

Fluorescence in situ hybridization (FISH) allows to diagnose aneuploidy in uncultured interphase nuclei. This rapid method of chromosomal analysis associated with cell-sorting techniques was realized on 47,XYY fetal cells isolated from maternal blood. Trophoblast cells were sorted by combining immunomagnetic removal of maternal lymphocytes and flow cytometry sorting using antitrophoblast monoclonal antibodies. Cells were sorted directly on slides and analyzed by FISH with a Y-centromeric probe. Among 1,387 examinable nuclei, 59 (4.25%) showed one single or two Y-specific domains.


Predictive value of uterine artery velocity waveforms in pregnancies complicated by systemic lupus erythematosus and the antiphospholipid syndrome.

The objective of this study was to see if determination of uterine artery velocity waveforms between 20 and 30 weeks in lupus pregnancy and the antiphospholipid syndrome (APS) have a good predictive value for later fetal distress before labor, intrauterine growth retardation, and preeclampsia. Uterine and umbilical artery blood flow velocity waveforms were determined in 21 pregnancies complicated by systemic lupus erythematosus (SLE): 12 with antiphospholipid antibodies (aPL), 9 without aPL. We also studied 7 pregnancies with APS. This retrospective study was running from January 1st 1986 to July 31st 1991, at the Port-Royal Maternity, Paris, France. Abnormal uterine artery blood flow velocity waveforms were found in 10 out of 28 pregnancies at the first examination performed between 20 and 30 weeks gestational age. All the later adverse fetal and neonatal events were predicted by an abnormal uterine artery blood flow velocity waveform. From the 7 cases of fetal distress diagnosed during pregnancy, 6 were predicted by abnormal uterine waveforms and all of these pregnancies resulted in induced delivery before 32 weeks of gestational age. Twelve pregnancies with aPL and normal uterine artery waveforms were uncomplicated. Only 1 out of 7 pregnancies with abnormal uterine artery waveform and aPL ended without complication. Determination of uterine artery flow velocity waveform is a good adjunct to the management of pregnancies complicated by SLE or aPL. This determination has a better predictive value than the presence of aPL.


[Trace element metabolism in healthy and sick children. II. The disease state].

In the last 3 decades, the discovery of importance of trace elements in structure and functions of many enzymes, provided a tremendous impetus for research on the physiopathology, metabolism, clinical pharmacology and toxicology of these micronutrients in human beings, specially, in children. This paper presents recent information on various pathological inherited and acquired conditions, with abnormal nutritional status in children, due either to deficiency or excess of some oligo-elements. The general aspects of abnormal metabolism, physiopathology, and some specific clinical features, are described.


[Differential physical growth during the first years of life. III. Body composition].

The present article report the results of longitudinally research, on growth children, of both sex and ages from 0 to 1 year of extrauterine life. We obtained measures that appraisal the muscular and fat tissues: upper arm and leg circumferences; muscle and fat of upper arm areas; triceps, subscapular and supra-iliac skinfolds. Moreover, we report relationship dates between weight and stature, which is a good indicator for morphological body equilibrium.


[IgA nephropathy (Berger's disease) in children].

IgA nephropathy, also called Berger's disease, is characterized by recurrent gross hematuria or persistent microscopic hematuria, together with mesangial glomerular deposits of IgA found in the renal biopsy. Seven children with IgA nephropathy were studied. Most of them presented initially with recurrent macroscopic hematuria and low or moderate-grade proteinuria, without hypertension or renal function impairment. Only one patient presented with a rapidly progressive glomerulonephritis. Four patients did not receive any treatment; one of them is in remission, one has improved and two remain with moderate proteinuria and hematuria. One patient with significant proteinuria improved after prednisone and azathioprine treatment. The patient with rapidly progressive glomerulonephritis improved his renal function after oral prednisone and intravenous boluses of methylprednisolone and cyclophosphamide.


[Nosocomial infection in newborn infants on mechanical ventilation].

During a two-year period (1988-1989), were studied newborns treated with intermittent mandatory ventilation (IMV). The goal was to know incidence of infections in these patients and characteristics of these process. Of 187, 40 (21.3%) were infected. For these neonates the mean gestational age was 33 +/- 3 weeks and average for birth weight was 1755 +/- 644 g. In 32 the infecting agent was isolated, being the most common coagulase negative Staphylococcus, it was found in 18 (45%), Klebsiella sp in 7 (17%), Escherichia coli in 1 and Candida albicans in 1. In the remaining 8 (20%) with negative cultures, postmortem confirmation was made in 5 and in 3 by clinical, radiologic or hematologic evidence. Of the 17 positive blood cultures and 3 spinal fluid culture, the same bacteria grew as in the bronchial aspirate. Were found, thrombocytopenia in 22 (55%) and leucocytosis in 19 (47%) as the most common blood changes. Pneumonia was the most common form of infection; it was found in 30 (75%); 22 of 40 died (55%). We concluded that 21.3% of neonates under IMV without infections, may get infected later in the hospital. S. epidermidis is the etiologic agent that predominates through the whole year, except during epidemics caused by others agents.


[Should computed axial tomography of the skull be done in all pediatric patients with epilepsy?].

The charts of 118 children with epilepsy (64 boys and 54 girls) from the Pediatric Hospital of the National Medical Center, Mexican Institute of Social Security, were surveyed. Results are as follow: 21% had a family history of epilepsy; 15.3% had pathological findings in simple skull x-ray. In 50% of the cases there were a normal CT scan and in the remaining 50% there were pathological findings, such as cerebral atrophy (12.7%) and neurocysticercosis (10%). The CT scan was abnormal in 51% of partial seizures cases and in 41.8% of those with generalized seizures. Electroencephalogram (EEG) was abnormal in 85.7% of both simple and complex seizures cases. EEG was abnormal in 85.4% of cases with generalized seizures. We do not intend to establish a comparison between EEG and CT scan, but to show the usefulness of CT scan in children with epilepsy. Finally an algorithm for correct CT scan prescription in children with epilepsy is proposed.


[Cataracts and atopic dermatitis in children. A study of 68 patients].

We choose 68 children with diagnosis of atopic dermatitis according to Hanifin's criteria, then they were sent to ophthalmologic exploration and were investigated other clinical data that could be related with ocular disturbances. The positive result for cataracts was found in three patients (4.4%) all of them females, 11, 12 and 18 years old respectively, with around 9 years of the onset of the disease. They were considered as severe according to the same criteria, all of them had familiar history of atopic diseases and tendency to generalize and to present eczematous phase in any moment of the evolution. These findings are similar to those reported by other authors and we remark the importance of recognizing risk factors in patients with this dermatosis to send opportunely to a periodic ophthalmologic evaluation.


[Systemic neonatal infection by Streptococcus pneumoniae. A case report].

The neonatal sepsis by Streptococcus pneumoniae is a clinical manifestation well know, but very often reported. It's role as an etiologic agent is limited to sporadic references in the medical literature, since 1972 only about fifty cases of septicaemia and/or meningitis have been reported. In the Instituto Nacional de Perinatología, from a whole of 560 confirmed cases of septicaemia in the newborn within the last 6 years, only one has been documented as systemic infections by S. pneumoniae. This was a 32.2 gestational aged male patient, with antecedent of maternal chorioamnionitis. This patient presented early-onset sepsis and died during the first 12 hours of life. Presence of S. pneumoniae was found in the blood culture. The type of clinical presentation and its correlation to the perinatal infection is discussed.


[Nutritional recommendations for the newborn infant].

The nutritional recommendations for newborn babies and infants change when there is an improvement on the technics and knowledge for evaluating requirements of each nutrient. In general, breast milk is enough for covering the nutritional requirements on healthy infants during the first six months of life. Therefore, the nutritional recommendations are focused to newborn babies and infants who do not receive exclusively breast milk or preterm infants whether they receive their own mother's milk or formula. The calculations are based on the assumption that mothers who breast fed their babies are healthy, well nourished and supplying daily a mean of 750 mL of breast milk during the period of lactation.


Synthesis and structural studies of a pentapeptide sequence of elastin. Poly (Val-Gly-Gly-Leu-Gly).

Poly (Val-Gly-Gly-Leu-Gly), a polypeptide mimicking the physico-chemical properties of the glycine-rich regions of elastin, has been synthesized and studied both in solution and in the aggregated state. By comparison, also the conformation of different "monomeric" units has been investigated. The polymer showed increased disorder with respect to the "monomers", the molecular conformation being accounted for by a more or less random collection of isolated beta-turns. Nevertheless, in the solid state the polymer is able to adopt supramolecular structures reminiscent of those found for elastin.


mRNA periodical infrastructure complementary to the proof-reading site in the ribosome.

Virtually all mRNA sequences carry a 3-base periodical pattern, presumably involved in the translation frame monitoring mechanism (Trifonov, E.N., J. Mol. Biol. 194, 643-652, 87). The hidden pattern, 5'-(GHN)n-3' (H representing nonG, N any base), is further refined by extensive computational analysis of mRNA sequences. According to mononucleotide preferences in the three positions of coding triplets, it appears now as 5'-(GHU)n-3'. Dinucleotide frequencies independent of mononucleotides (contrast dinucleotides, 2) generate the motif 5'-(GCU)n-3'. The same motif is found by regarding the expected avoidance of destabilizing base oppositions in hypothetical transient complementary complexes between mRNA and rRNA. This hidden pattern, in its refined consensus form, 5'-(GCU)n-3', is an almost perfect complementary match to a unique site in small subunit rRNA, the universally conserved (3) proofreading loop at position 525 (of E.coli small subunit rRNA): [formula: see text] This strongly suggests that the 525 site is a major structural component of the previously proposed frame-keeping mechanism which is based on the in-frame contacts between mRNA and three segments of rRNA. Consistent with the original proposition, this site is one of three believed to interact with mRNA.


A high angle neutron fibre diffraction study of the hydration of the A conformation of the DNA double helix.

A high angle neutron fibre diffraction study of the distribution of water around the A-form of DNA has been performed using the diffractometer D19 at the Institut Laue-Langevin, Grenoble. These experiments have exploited the ability to replace H2O surrounding the DNA by D2O so that isotopic difference Fourier maps can be computed in which peaks are identified with the distribution of water in the unit cell. All peaks of significant height have been accounted for by four families of water molecules whose positions and occupancies have been determined using least squares refinement. The coordinates of the water peaks making up each family do not deviate significantly from a regular helical arrangement with the same parameters as the DNA. Two of these families are of particular interest. The first consists of water molecules in the major groove linking successive charged phosphate oxygens along the polynucleotide chains. The second is associated with bases in the major groove and forms a central core of density along the helix axis. These two families provide a layer of hydration lining the interior wall of the major groove leaving a central channel to accommodate cations. The relationship between these observations and conformational stability is discussed.


Binding of nucleic acids to intermediate filaments of the vimentin type and their effects on filament formation and stability.

Guanine-rich polynucleotides such as poly(dG), oligo(dG)12-18 or poly(rG) were shown to exert a strong inhibitory effect on vimentin filament assembly and also to cause disintegration of preformed filaments in vitro. Gold-labeled oligo(dG)25 was preferentially localized at the physical ends of the aggregation and disaggregation products and at sites along filaments with a basic periodicity of 22.7 nm. Similar effects were observed with heat-denatured eukaryotic nuclear DNA or total rRNA, although these nucleic acids could affect filament formation and structure only at ionic strengths lower than physiological. However, whenever filaments were formed or stayed intact, they appeared associated with the nucleic acids. These electron microscopic observations were corroborated by sucrose gradient analysis of complexes obtained from preformed vimentin filaments and radioactively labeled heteroduplexes. Among the duplexes of the DNA type, particularly poly(dG).poly(dC), and, of those of the RNA type, preferentially poly(rA).poly(rU), were carried by the filaments with high efficiency into the pellet fraction. Single-stranded 18S and 28S rRNA interacted only weakly with vimentin filaments. Nevertheless, in a mechanically undisturbed environment, vimentin filaments could be densely decorated with intact 40S and 60S ribosomal subunits as revealed by electron microscopy. These results indicate that, in contrast to single-stranded nucleic acids with their compact random coil configuration, double-stranded nucleic acids with their elongated and flexible shape have the capability to stably interact with the helically arranged, surface-exposed amino-terminal polypeptide chains of vimentin filaments. Such interactions might be of physiological relevance in regard to the transport and positioning of nucleic acids and nucleoprotein particles in the various compartments of eukaryotic cells. Conversely, nucleic acids might be capable of affecting the cytoplasmic organization of vimentin filament networks through their filament-destabilizing potentials.


Aflatoxin B1 and DNA adducts. Proposed model for surface noncovalent and covalent complexes with N(7) of guanine. II.

An alternate model for surface noncovalent and surface covalent binding of aflatoxin B1 to N(7) of guanine in DNA is proposed. This model considers the out-of-plane motions of C(8) of aflatoxin B1 in those interactions. The covalent intercalated fit of aflatoxin B1 into DNA arises from steric adjustments made by DNA at the covalent intercalation site as well as local strain in the bond angles about N(7) of guanine and C(8) of aflatoxin B1. The bond angle about N(7) deviates modestly from the sp2 value toward the sp3 value. This study suggests that the surface covalent aflatoxin B1-DNA complex serves only a minor role in aflatoxin's precarcinogenic interaction with DNA and is a likely correctable error.


DNA binding of the nonintercalative ligands SN-6132, SN-6131 and SN-6113: minor variations of the ligand structure may cause changes in the base pair preference.

The DNA binding selectivity of three ligands of a series of antitumor agents of bisquaternary ammonium heterocycles has been investigated by means of CD spectroscopy and melting measurements. From the spectroscopic results and binding data it is concluded that the agents SN-6132, SN-6131 and SN-6113 have relatively high affinity to AT base pair sequences whereas the binding to GC pairs is very low. The binding selectivity to AT base pair sequences decreases in the order netropsin > SN-6132 > SN-6113 > SN-6131. Poly(dA).poly(dT) has the highest binding preference for SN-6132 relative to that of SN-6131. The different binding behavior of the ligands is related to their distinct changes in the chemical structure and to the DNA minor groove properties which determines the adaptability of the ligands in the groove.


Triple helical polynucleotidic structures: an FTIR study of the C+ .G. Ctriplet.

Triple helixes containing one homopurine poly dG or poly rG strand and two homopyrimidine poly dC or poly rC strands have been prepared and studied by FTIR spectroscopy in H2O and D2O solutions. The spectra are discussed by comparison with those of the corresponding third strands (auto associated or not) and of double stranded poly dG.poly dC and poly rG.poly rC in the same concentration range and salt conditions. The triplex formation is characterized by the study of the base-base interactions reflected by changes in the spectral domain involving the in-plane double bond vibrations of the bases. Modifications of the initial duplex conformation (A family form for poly rG.poly rC, B family form for poly dG.poly dC) when the triplex is formed have been investigated. Two spectral domains (950-800 and 1450-1350 cm-1) containing absorption bands markers of the N and S type sugar geometries have been extensively studied. The spectra of the triplexes prepared starting with a double helix containing only riboses (poly rC+.poly rG.poly rC and poly dC+.poly rG.poly rC) as well as that of poly rC+.poly dG.poly dC present exclusively markers of the North type geometry of the sugars. On the contrary in the case of the poly dC+.poly dG.poly dC triplex both N and S type sugars are shown to coexist. The FTIR spectra allow us to propose that in this case the sugars of the purine (poly dG) strand adopt the S type geometry.


Atomic force microscopy imaging of double stranded DNA and RNA.

A procedure for imaging long DNA and double stranded RNA (dsRNA) molecules using Atomic Force Microscopy (AFM) is described. Stable binding of double stranded DNA molecules to the flat mica surface is achieved by chemical modification of freshly cleaved mica under mild conditions with 3-aminopropyltriethoxy silane. We have obtained striking images of intact lambda DNA, Hind III restriction fragments of lambda DNA and dsRNA from reovirus. These images are stable under repeated scanning and measured contour lengths are accurate to within a few percent. This procedure leads to strong DNA attachment, allowing imaging under water. The widths of the DNA images lie in the range of 20 to 80nm for data obtained in air with commercially available probes. The work demonstrates that AFM is now a routine tool for simple measurements such as a length distribution. Improvement of substrate and sample preparation methods are needed to achieve yet higher resolution.


Atomic force microscopy of uncoated plasmid DNA: nanometer resolution with only nanogram amounts of sample.

Reproducible, high-contrast, nanometer-resolution AFM images of uncoated plasmid DNA can be obtained with nanogram quantities of DNA with the help of two advances in sample preparation: (1) Heating a DNA solution at 35 degrees C for 10 to 20 minutes before deposition on mica helps separate and spread the DNA, and (2) Using 5 microliter drops of the heated DNA solution in the concentration range of 2 to 10 nanogram/microliter in contact with a specially prepared mica surface for 5 to 10 minutes gives optimal coverage with only nanograms of DNA.


Cation-dependence of the self-association behavior of guanylyl-(3'-5')-guanosine.

The aggregation behavior of guanylyl-(3'-5')-guanosine, GpG, in the form of the tetramethylammonium (TMA), Li, Na, and K salts in aqueous solution has been investigated by NMR and FTIR techniques. The salts were prepared by a cation-exchange method. The ability of the cations to induce aggregate formation is TMA+ < Li+ < Na+ < K+, where TMA+ has only a weakly promoting action and K+ has a very strong effect. Three types of aggregates have been observed: (a) small aggregates which are in rapid exchange with respect to the NMR time scale; (b) intermediate-sized aggregates which are slow to exchange; (c) very large aggregates which can only be observed by FTIR. In all cases the aggregated species are held together by base stacking and guanine-guanine hydrogen bonding. A stoichiometry of 2 GpG per K+ has been determined by a 1H NMR titration of TMAGpG with KCl. Models have been proposed for the various-sized species. These include stacked dimers, stacked tetramers (similar to G-tetrads), and species in which K+ ion bridges between phosphates in separate tetramers.


Zidovudine-resistant and -sensitive HIV-1 isolates from patients on drug therapy: in vitro studies evaluating level of replication-competent viruses and cytopathogenicity.

To compare biological properties of zidovudine-resistant variants of HIV-1 isolated from subjects on long-term drug therapy with drug-sensitive parental isolates obtained from the same patients before initiation of treatment. Clinical HIV-1 strains were isolated following co-incubation of patient peripheral blood mononuclear cells with mitogen-stimulated umbilical cord blood lymphocytes. Drug resistance was evaluated by infecting MT-4 cells pretreated with zidovudine and maintained under drug pressure. The drug-resistant phenotype remained stable, following many viral replication cycles in the absence of zidovudine. Drug-resistant variants contained fewer replication-competent viruses but were more cytopathogenic than their corresponding zidovudine-sensitive parental strains. These results suggest that drug-resistant strains possess biological properties that may differ from those of drug-sensitive variants of HIV-1.