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At least 721 records · Page 40Linked to original sources

Human sweat and 2-oxopentanoic acid elicit a landing response from Anopheles gambiae.

A wind tunnel bioassay and video to observe mosquitoes landing on heated glass cylinders were used to test sweat and some derivatives for responses of Anopheles gambiae Giles (Diptera: Culicidae), a highly anthropophilic African species of malaria vector. Filter papers impregnated with human sweat and a diethyl ether extract from the filter papers elicited significantly more landings than a water control (P<0.001). The concentration of lactic acid in the extract was determined by GLC assay, but bioassays of an equivalent dose of lactic acid (from a commercial supplier) did not elicit landings. Chemical analysis of the extract by combined GLC/mass spectrometry indicated the presence of 73 compounds, of which 40 were tentatively identified. The major components of the extract were aliphatic carboxylic acids. An artificial blend of 22 carboxylic acids did not elicit landings. Bioassays of 2-oxopentanoic acid elicited significantly more, landings (P<0.001). The possible importance of oxo-carboxylic acids for host-seeking by anthropophilic mosquitoes is discussed and their use for trapping is suggested.

Animals↗

[Treatment of atypical absences with a combination of succinimide and dipropylacetate (author's transl)].

Fifteen epileptic patients with mild seizures of the narcolepsy type were treated with a combination of succinimide (average dose 750 mg) and dipropylacetate (average dose 1,200 mg), medication with each drug alone having brought no success. The combination of drugs stopped the seizures in eleven patients, in three they almost stopped and in one the frequency of seizures was halved. An E.E.G. was recorded in twelve, with improvement in each. Side effects occurred in five patients (nausea, vomiting, singultus and fatigue), but the drug had to be discontinued in only one instance.

Adolescent↗

Partial purification and characterization of two enzymes involved in isovaleric acid synthesis in Clostridium bifermentans.

Conversion of leucine to isovaleric acid by Clostridium bifermentans is achieved by the action of at least two enzymes. One is a transaminase producing alpha-ketoisocaproic acid, which was purified 30-fold from osmotic lysates of late-exponential phase cells by repeated chromatography on DEAE-Sepharose C16B and Sephacryl S300: this represented a 147-fold purification of activity found in sonically disrupted cells. This enzyme had an apparent molecular weight of approximately 190000 and was composed of six identically sized sub-units (molecular weight 31000 +/- 1000). Transamination required pyridoxal phosphate and pyruvate and was optimal at pH 8.6; the apparent Km for leucine was 7.0 mM. Activity was totally inhibited by 1 mM-p-chloromercuribenzoate and partially inhibited by other thiol reagents. The second enzyme decarboxylated alpha-ketoisocaproic acid to form isovaleric acid and was also partially purified by chromatography on DEAE-Sepharose C16B and Sephacryl S300. It has an apparent molecular weight of 240000 and required FAD and coenzyme A for activity; the Km for alpha-ketoisocaproic acid was 4.2 mM and activity was optimal around pH 8.0. This enzyme was a flavoprotein with absorption maxima at 280, 320 and 400 nm, and a fluorescent maximum at 500 nm. The prosthetic group, FAD, dissociated from the protein during purification resulting in an inactive apoenzyme which was only partially re-activated by FAD. Activity was completely inhibited by several thiol reagents tested at 1 mM.

Carboxy-Lyases↗

Birthweights in the Faroe Islands: possible role of isovaleric acid.

A high intake of n-3 polyunsaturated fatty acids has been suggested as a factor in prolonged gestation in the population of the Faroe Islands. It is now suggested that isovaleric acid from pilot whales, a species frequently consumed in the Faroe Islands, may be the unusual dietary factor. Fatty acid data for eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) in blood lipids of Faroese and Norwegians is reviewed in terms of the type of fish eaten, apparently mostly lean white fish with DHA much greater than EPA. The popular lean fish, thus, probably provides too little EPA to produce a marked effect on human biochemistry.

Birth Weight↗

Gas chromatographic measurement of plasma levels of sodium valproate: tentative therapeutic range of a new anticonvulsant in the treatment of refractory epileptics.

1. A precise and rapid gas chromatographic method for the measurement of plasma sodium valproate concentrations is presented. 2. The extraction is a single step procedure, and is reproducible and linear throughout the concentration range encountered. 3. Clinical evaluation of the drug is presented in eighteen epileptics on the basis of the percentage of days on which subjects had seizures before and after sodium valproate therapy. 4. A tentative therapeutic range for sodium valproate is presented on the basis of plasma levels and therapeutic effect.

Chromatography, Gas↗

Sodium valproate in the treatment of intractable childhood epilepsy.

Sodium valproate has been used, in combination with a variety of standard anticonvulsant drugs, to treat 24 children with intractable epilepsy. A reduction of fit frequency greater than 90 percent was obtained in six patients, and a reduction of over 50 per cent in another six, with an improvement in alertness and school performance in the majority of cases. Grand mal, myoclonic and petit mal epilepsy gave the best response, while infantile spasms responded least well. No serious side-effects were encountered.

Adolescent↗

The use of sodium valproate in a case of status epilepticus.

A child in status epilepticus, who did not respond to intravenous diazepam, was treated with sodium valproate by naso-gastric tube. Subsequent clinical and encephalographic improvement appeared to be related to the sodium valproate, and its value in cases of status epilepticus is discussed.

Child↗

Treatment of generalized epilepsies of childhood and adolescence with sodium valproate ("epilim").

A total of 142 patients (84 per cent aged less than 20 years) with various forms of generalized epilepsy have been treated with sodium valproate alone or in combination with other drugs. The mean duration of symptoms was six years, and half the patients had daily seizures. Nine patients had typical absences, 33 had absences with automatisms, 28 had tonic-clonic seizures with or without photosensitivity, and 72 had various forms of myoclonic epilepsy. Dosage varied from 23 to 54mg/kg and twice-daily administration was usual. Estimation of serum levels did not assist in management. Fits ceased in 63 per cent of all cases and a further 18 per cent showed improvement greater than 50 per cent. Of the 69 with 3c/sec spike-and-wave discharges, 81 per cent became free from all fits, as did 77 percent of those with myoclonic jerks. Fits ceased in eight of the 32 patients with myoclonic astatic epilepsy and there was improvement greater than 50 per cent in a further eight patients. Other anticonvulsants were often withdrawn and always reduced. 21 patients received sodium valproate alone from the start of treatment and all other drugs were withdrawn in another 38. Sodium valproate alone controlled all fits in four children with absences, in 18 with absences with automatisms, 10 with tonic-clonic seizures and 22 with myoclonic epilepsy. Side-effects were rare, mild and often temporary. Potentiation of barbiturates and benzodiazepines occurred, especially clonazepam, which should be avoided. Many patients were more alert. Sodium valproate appears to be the drug of choice for epilepsies associated with generalized spike-and-wave discharges, myoclonic epilepsies or photosensitive epilepsies, and is of especial value in children and mentally retarded patients because it lacks sedating effects and often induces liveliness.

Adolescent↗

Actions and interactions of dipropylacetate and penicillin on evoked potentials of excised prepiriform cortex of guinea pig.

Slices from guinea pig brain containing the lateral olfactory tract (LOT) and the prepiriform cortex were studied in vitro. Field potentials, evoked by stimulation of the LOT, were recorded extracellularly. This field potential comprises a compound action potential, a surface negative wave (identified as EPSP), and superimposed positive peaks ("population spikes" or PSs) reflecting postsynaptic activity. In a previous article the penicillin-induced increase of EPSP and of both amplitude and number of PSs was described. Now we are reporting the slight depression of EPSP and PSs and the prevention of the appearance of penicillin-induced PSs by an antiepileptic drug sodium dipropylacetate (Depakine). The effect was dose-dependent. Models explaining the effects of penicillin and dipropylacetate are discussed.

Animals↗

Concentration of dipropylacetate in plasma.

Dipropylacetate is absorbed rapidly and attains a maximum concentration in serum 1 to 3 hr after ingestion. Since its half-life is on the order of 8 to 10 hr, it must be prescribed three times a day, every 8 hr. It reaches a stable concentration in blood within 48 hr after treatment is begun (by contrast with diphenylhydantoin and phenobarbital) and might therefore be useful when seizures must be controlled quickly. The serum concentration can be altered by some other anticonvulsant drugs, but these interactions should be studied in more detail. The serum concentration varies considerably in the course of a day and from one day to the next in the same subject, which makes it difficult to adjust the blood level. Depamide is rapidly transformed in vivo to dipropylacetate.

Administration, Oral↗

Has sodium valproate hypnotic effects?

Eight fasting normal subjects were given a single dose of sodium valproate, 400 mg, phenobarbital, 60 mg, or the two drugs in combination, in a double-blind placebo-controlled study. The effects were assessed behaviorally and by a standard 30-min EEG, begun 1 hr after the treatments had been given. The recording was rated for the amount of drowsiness and sleep, independent of which drug had been given. The scores obtained indicated that valproate intself has hypnotic action, and there is a tendency for this to be increased by the simultaneous administration of phenobarbital.

Adult↗