Community nurses' practices in managing perianal abscesses.

A survey of community nurses identified that a wide range of dressings, and in some cases unethical practices, are being used for this simple postoperative condition. Communication between hospital, community staff and patients was poor.

Should ABPI be measured in patients with healed venous leg ulcers every three months?

OBJECTIVE: To assess if three-monthly reassessment of ABPI is necessary and to determine the possibility of identifying which patients may benefit from more frequent reassessment. METHOD: The sample comprised 88 consecutive patients with 175 limbs attending community leg ulcer clinics for reassessment after leg ulcer healing had been achieved with compression therapy. Outcome measures were: a fall in ABPI to below 0.8, months between reassessments and arterial disease history. RESULTS: ABPI fell from above 0.8 to below 0.8 in seven limbs in six patients over time periods of between six and 24 months. Of these seven limbs, six had an ABPI between 0.8 and 1.0 at the initial assessment, indicating they had some arterial impairment. ABPI fell below 0.7 (0.58) in only one patient, and this was detected at a six-month reassessment. None of the patients with no or just one arterial symptom experienced a reduction in ABPI to below 0.8. Those whose ABPIs fell below this level had two or more arterial symptoms. CONCLUSION: Three-monthly reassessment of healed limbs is not recommended as most patients who initially have an ABPI above 1.0 are unlikely to change during this time. However, patients with two or more arterial risk factors, diabetes and an initial ABPI of below 1.0 are likely to need closer monitoring. More in-depth research is needed to examine this problem.

Crystal structure of a soluble form of the intracellular chloride ion channel CLIC1 (NCC27) at 1.4-A resolution.

CLIC1 (NCC27) is a member of the highly conserved class of chloride ion channels that exists in both soluble and integral membrane forms. Purified CLIC1 can integrate into synthetic lipid bilayers forming a chloride channel with similar properties to those observed in vivo. The structure of the soluble form of CLIC1 has been determined at 1.4-A resolution. The protein is monomeric and structurally homologous to the glutathione S-transferase superfamily, and it has a redox-active site resembling glutaredoxin. The structure of the complex of CLIC1 with glutathione shows that glutathione occupies the redox-active site, which is adjacent to an open, elongated slot lined by basic residues. Integration of CLIC1 into the membrane is likely to require a major structural rearrangement, probably of the N-domain (residues 1-90), with the putative transmembrane helix arising from residues in the vicinity of the redox-active site. The structure indicates that CLIC1 is likely to be controlled by redox-dependent processes.

The propeptide of the transforming growth factor-beta superfamily member, macrophage inhibitory cytokine-1 (MIC-1), is a multifunctional domain that can facilitate protein folding and secretion.

Macrophage inhibitory cytokine-1 (MIC-1) is a divergent member of the transforming growth factor-beta (TGF-beta) superfamily. While it is synthesized in a pre-pro form, it is unique among superfamily members because it does not require its propeptide for correct folding or secretion of the mature peptide. To investigate factors that enable these propeptide independent events to occur, we constructed MIC-1/TGF-beta1 chimeras, both with and without a propeptide. All chimeras without a propeptide secreted less efficiently compared with the corresponding constructs with propeptide. Folding and secretion were most affected after replacement of the predicted major alpha-helix in the mature protein, residues 56-68. Exchanging the human propeptide in this chimera with either the murine MIC-1 or TGF-beta1 propeptide resulted in secretion of the unprocessed, monomeric chimera, suggesting a specific interaction between the human MIC-1 propeptide and mature peptide. Propeptide deletion mutants enabled identification of a region between residues 56 and 78, which is important for the interaction between the propeptide and the mature peptide. Cotransfection experiments demonstrated that the propeptide must be in cis with the mature peptide for this phenomenon to occur. These results suggest a model for TGF-beta superfamily protein folding.

Social structure of the mara (Dolichotis patagonum) as a determinant of gastro-intestinal parasitism.

A one-year study of gastro-intestinal parasitism in a free-ranging population of maras at Whipsnade Wild Animal Park, UK, revealed a strong relationship between membership of social units and both intensity and prevalence of infection. The mara, a hystricomorph rodent from southern Argentina, has a social organization including both monogamy and communal denning of the young, an apparently unique combination among mammals. From October 1992 to September 1993, strongyloid parasite loads were estimated from faecal egg counts. A minimum adequate model was fitted to the data using the Genstat statistical package. This showed that family membership had a highly significant effect on the intensity of egg shedding in faeces, and a significant effect on the prevalence of infection. After controlling for both extrinsic environmental and intrinsic demographic factors, homogeneity of infection was greater within than between families and adult pairs.