Fungus wars: basidiomycete battles in wood decay

Understanding the mechanisms underlying wood decay basidiomycete community dynamics is crucial for fully understanding decomposition processes, and for modelling ecosystem function and resilience to environmental change. Competition drives community development in decaying woody resources, with interactions occurring at a distance, following physical contact, and through specialised relationships such as mycoparasitism. Outcomes of combative interactions range from replacement, where one mycelium displaces another, to deadlock, where neither combatant captures territory from the other; and a spectrum of intermediate outcomes (i.e. partial or mutual replacement) lie between these extremes. Many wood decay basidiomycetes coexist within a resource, in a complex and dynamic community, and new research techniques are focussing on spatial orientation of interactions in 3 dimensions, as opposed to historical two-dimensional research. Not only do interactions drive changes in species composition and thus wood decomposition rate, they also may have industrial applications in biocontrol of pathogenic or nuisance fungi, enzyme production, and in the production of novel antifungals and antibiotics. Altogether, fungal interactions are a fascinating and important field of study.

Non-invasive assessment of cardiac output in children

BACKGROUND

Stroke distance, the systolic velocity integral of aortic blood flow, is a linear analogue of stroke volume; its product with heart rate is minute distance, analogous to cardiac output.

OBJECTIVE

To investigate the feasibility of assessing cardiac output in children with a simple non-invasive Doppler ultrasound technique, and to determine the normal range of values.

METHODS

Peak aortic blood velocity, stroke distance, and minute distance were measured through the suprasternal window in 166 children (mean age 9.6 years, range 2-14) using a portable non-imaging Doppler ultrasound instrument.

RESULTS

The technique was well tolerated by all the children participating. Mean peak aortic blood velocity was 138 cm/s and was independent of age. Mean stroke distance was 31.8 cm and showed a small but significant increase with age; mean minute distance was 2490 cm and fell with age, as did heart rate.

CONCLUSIONS

Suprasternal Doppler ultrasound measurement of stroke distance is a convenient, well tolerated, non-invasive technique for the assessment of cardiac output in children. The normal range of values during childhood has been established. The technique has great potential for assessing hypovolaemia in children.

A pilot study to assess the sensitivity and specificity of an intrasound device in the diagnosis of ankle fractures

OBJECTIVE

To investigate the use of a simple intrasound device in the detection of malleolar fractures in the accident and emergency (A&E) department.

METHODS

Patients aged 16 to 70 years with ankle injuries presenting within 24 hours were considered for inclusion in the study. Those patients with bony tenderness, inability to weight bear, and swelling were examined with a simple intrasound device before x-ray examination. A positive result of discomfort, pain, withdrawal response, or combinations or these was noted.

RESULTS

The device had a sensitivity of 85% and a specificity of 52% in detecting malleolar fractures.

CONCLUSIONS

The use of intrasound in the detection of malleolar fractures cannot be relied upon alone, but it may help to limit the number of x rays taken unnecessarily. A further study is proposed to confirm these findings.

Section 9 police statement: a guide for junior doctors

In England and Wales the police require medical evidence in crimes committed against a person. This will take the form of either a verbal statement given to a police officer under his/her direction, or a written report compiled by the doctor. Police surgeons regularly compile these reports without any complications. However, for many junior doctors they have potential pitfalls. This article is aimed primarily at junior doctors and GPs who are asked infrequently to provide medical evidence in criminal cases.

Control of TGEV mRNA transcription

Coronavirus proteins are translated from a nested set of subgenomic mRNAs which have common 3' termini with unique 5' extensions. Evidence suggests that coronavirus mRNAs are generated by a mechanism of leader primed transcription. Leader RNA binds to consensus sequences upstream of each gene on full length negative strand viral RNA and transcription proceeds to the 5' end of the negative strand to produce the nested set of mRNAs. Even though this gives rise to polycistronic mRNA species only the 5' extension of each mRNA is translated to give the viral proteins. The leader RNA for TGEV is about 90 nucleotides long and contains the sequence which recognises the leader binding sites on the negative strand RNA. Evidence suggests that the length of the leader binding sequence may be involved in transcriptional control of individual mRNAs. In order to investigate this a virus specific mRNA isolation method was developed to measure the relative amounts of mRNAs synthesised during an infection of LLC-PK1 cells with TGEV (strain FS772/70). Thus the relative quantity of each mRNA can be determined and correlated with the variation in size of the leader binding site.