Search

Microsatellite markers are quite popular due to their degree of polymorphism and efficiency; however, the utility of such markers for analysing allotetraploid species is often hampered by an inability to determine allele copy number for partial heterozygotes. tetrasat is a program that uses an iterative substitution process to account for all probable combinations of allele copy numbers in populations with partial heterozygote samples. The program subsequently calculates allele frequencies, and mean Hardy–Weinberg expected heterozygosity (HE), Shannon–Weiner Diversity Index (H′) and Nei's measure of population differentiation (GST) are reported for each locus and population. Of equal importance is the calculation of statistical variability generated by the missing data and allele substitution process, which allows for assessment of the strength of conclusions drawn from the statistics.

Salvia divinorum is a widespread hallucinogenic herb traditionally employed for divination, as well as a medicament for several disorders including disturbances of gastrointestinal motility. In the present study we evaluated the effect of a standardized extract from the leaves of S. divinorum (SDE) on enteric cholinergic transmission in the guinea-pig ileum. SDE reduced electrically evoked contractions without modifying the contractions elicited by exogenous acetylcholine, thus suggesting a prejunctional site of action. The inhibitory effect of SDE on twitch response was abolished by the opioid receptor antagonist naloxone and by the kappa-opioid antagonist nor-binaltorphimine, but not by naltrindole (a delta-opioid receptor antagonist), CTOP (a mu-opioid receptor antagonist), thioperamide (a H(3) receptor antagonist), yohimbine (an alpha(2)-receptor antagonist), methysergide (a 5-hydroxytryptamine receptor antagonist), N(G)-nitro-L-arginine methyl ester (an inhibitor of NO synthase) or apamin (a blocker of Ca(2+)-activated K(+) channels). Salvinorin A, the main active ingredient of S. divinorum, inhibited in a nor-binaltorphimine- and naloxone-sensitive manner electrically induced contractions. It is concluded that SDE depressed enteric cholinergic transmission likely through activation of kappa-opioid receptors and this may provide the pharmacological basis underlying its traditional antidiarrhoeal use. Salvinorin A might be the chemical ingredient responsible for this activity.

A fine-needle aspiration (FNA) service for the diagnosis of palpable breast lumps was started at the Royal Preston Hospital, Preston, UK, in November 1989. Over the subsequent year, 407 FNAs were taken from 393 women. A simple technique was used which involved the surgeon flushing the aspirate into 10 ml of Cytospin collection fluid; cytocentrifuge preparations were then safely and conveniently prepared in the laboratory. Slides were stained with Papanicolaou and HE. The method detected 112 out of a total of 121 cancers (92.6%); of the nine that were undetected, five aspirates were inadequate and four were falsely reported as negative. There were no false positives. The overall inadequate rate was 11.0%. Excluding inadequate samples, the absolute sensitivity was 89.7% and complete sensitivity 96.6% with 94.4% specificity. This 1-year audit has shown the Cytospin method of FNA in palpable breast disease to have a favourable sensitivity and specificity, and therefore to be an alternative to conventional FNA using direct smears.

A simple most probable number (MPN) method has been developed for the enumeration of sulphate-reducing bacteria (SRB) in biocide-containing waters. The medium used is based on source water, it contains no toxic thioglycollate and is resistant to oxidation through mishandling. Reduction is by a suspension of Pseudomonas putida which acts as a powerful adsorbent of biguanide, phenolic, quaternary ammonium compound, glutaraldehyde and isothiazolone biocides. Good recoveries of SRB type strains were obtained using this method and were comparable to other published techniques. Recovery of SRB in mixed culture was comparable to that using a standard laboratory technique.

The meander-belt deposit comprises a sandstone resting on an erosion surface and bounded above and below by massive varicoloured mudstones with rootlet traces. The sandstone unit is composed of six bodies separated from one another, horizontally, by erosion surfaces; together the bodies form a single multilateral sand body. Internally each body is composed of lateral accretion units inclined at up to 6° from the horizontal. Vertical sequences of facies show significant variations but the grain size generally fines upwards. The principal lithofacies within the sandstones are, in common ascending order, intraformational conglomerate, large-scale cross-bedded, horizontal bedded and small-scale cross-laminated sandstone, and alternate sandstones and mudstones. Current directions are normal to the true slope of accretion surfaces and show insignificant scatter within individual bodies but are very diverse overall. Five of the sand bodies are believed to represent individual point bars, and one body an abandoned channel. Together they comprise the meander belt. The river was subject to very variable discharges and carried high suspended loads. Analysis of vertical profiles indicates that grain size segregation along the length of the point bars caused differentiation of the bars into coarse-grained heads and sandy tails.

Continuous and batch cultures of marine sulphate-reducing bacteria (SRB) in North Sea water were irradiated with 110000 to 329500 μWs/cm2 of ultraviolet radiation (wavelength 253.7 nm) with a commercial u.v. sterilizing unit. A 100% kill was obtained with logarithmic cultures of Desulfovibrio desulfuricans NCIMB 8400 at population densities of 10–104/ml. A >99.99% kill was obtained with a mixture (ca 105/ml) of batch grown Desulfovibrio spp. and oilfield SRB enrichments. Ultraviolet irradiation was less effective against the indigenous heterotrophic bacteria in the seawater (ca 90% kill).

Three young patients with gingival injuries that were self-inflicted by a fingernail habit are presented. In each case the habit, which was provoked by a pre-existing locus of irritation, was stopped as soon as the locus (or trigger) was identified and treated. A distinction is drawn between these types of cases, (gingivitis artefacta minor), and those of gingivitis artefacta major where the habit is more deeply entrenched and the implications more serious.

Summary In a rapid technique for detecting L-glutamic acid decarboxylase activity in lactose fermenting colonies growing on purple MacConkey's agar the colonies, after exposure to toluene vapour for 30 min, are removed from the agar surface with small filter paper discs and allowed to act on a buffered substrate containing 1% of L-glutamic acid for 1 h. The amino acids are extracted from the disc with a small drop of water and separated by paper chromatography in 1–3 h. A considerable increase in decarboxylase activity was produced by exposing the cells to toluene vapour. Pyridoxal-5-phosphate in the substrate also stimulated activity to a lesser degree.