What makes a good head positioner for preventing occipital pressure ulcers

Patients who are stationary endure prolonged soft tissue distortions and deformations at contact areas between their body and the support surface, which may lead to the onset of pressure ulcers (PUs) over time. A novel technology for patient positioning employs innovation in materials science, specifically viscoelastic materials with shape memory properties that compose the Z‐Flo™ head positioner (Mölnlycke Health Care, Gothenburg, Sweden). Head positioners are generally known to reduce the occurrence of PUs in scalp tissues and the ears, but quantitative assessments of their biomechanical efficacy are missing in the literature. To determine potential differences in mechanical loads formed in the soft tissues of the back of the head while in contact with 2 head positioner types, Z‐Flo vs flat medical foam, we developed 2 comparable finite element model configurations, both including the same 3‐dimensional adult head. For both model variants, stresses in skin and fat peaked at the occiput. The skin at the back of the resting head is subjected to greater stress values with respect to fat; however, the Z‐Flo positioner reduced the exposure of both skin and fat tissues to elevated stresses considerably (by a factor of 3) compared to the medical foam support. We found the Z‐Flo device effective in reducing tissue loads at the surface of the head as well as internally in scalp tissues, with a particular strength in reducing internal tissue shear. The Z‐Flo device achieves this protective quality through highly effective immersion and envelopment of the back of the head, generated in the process of manual moulding of the device in preparation for use. Additional protection is achieved through the viscoelastic response of the filling material of this positioner, which relaxes promptly and considerably under the weight of the head (by more than 2‐fold within approximately 1 s) as opposed to the elastic recoil of the foam that pushes back on scalp tissues.     

Automated classification of neonatal sleep states using EEG

Objective

To develop a method for automated neonatal sleep state classification based on EEG that can be applied over a wide range of age.

Overexpression of bcl-xL Protects Astrocytes from Glucose Deprivation and Is Associated with Higher Glutathione, Ferritin, and Iron Levels

Background: The possibility of altering outcome from ischemia-like injury by overexpressing the anti-cell death gene bcl-xL was studied. Cells are known to die by different pathways including apoptosis, or programmed cell death, and necrosis. The bcl-xL gene is a member of a family of apoptosis regulating genes and often displays the death-inhibiting properties of the prototype of this family, bcl-2. It is of special interest to study bcl-xL for possible brain protection, because, unlike bcl-2, it is important for normal brain development.

Methods: Overexpression of bcl-xL was achieved in primary astrocyte cultures using a retroviral vector. Cultures of astrocytes overexpressing bcl-xL or a control gene were injured by hydrogen peroxide, glucose deprivation, or combined oxygen and glucose deprivation. Outcome was assessed morphologically and by release of lactate dehydrogenase. We assessed antioxidant effects by measuring glutathione using monochlorobimane, ferritin by immunoblotting, the level of iron spectrophotometrically, and superoxide using iodonitrotetrazolium violet and dihydroethidium.

Results: Protection by bcl-xL was found against glucose deprivation and hydrogen peroxide exposure but not combined oxygen and glucose deprivation. Higher levels of superoxide were found, without increased levels of lipid peroxidation. Overexpression of bcl-xL was associated with elevated glutathione levels, elevated ferritin levels, and increased amounts of iron. The increased glutathione contributed to the protection from glucose deprivation.     

THE INFLUENCE OF DOWN''S SYNDROME ON SIBLING INTERACTION

Home observations were done on sibling interactions in 31 families with a child having Down's syndrome and a non-handicapped sibling. The siblings with Down's syndrome initiated less prosocial and agonistic behaviour, but imitated more frequently than their non-handicapped siblings. These effects were found regardless of birth order. There were no effects of gender. Higher levels of prosocial behaviours among large interval dyads and in dyads with a second-born Down's syndrome child were primarily due to the age of the non-handicapped sibling. Results were similar to those in previous "normative" studies of sibling interactions.     

The origin of DNA replication and Fieller's problem

The paper considers the statistical problem of estimating the origin of DNA replication within the human ribosomal DNA (rDNA) locus and the issue of assessing the standard error of the estimate. Based on mapping the cumulative replication index (CRI), two different modelling schemes are suggested and investigated. The statistical problem of constructing a confidence interval for the origin of DNA replication is related to Fieller's problem of obtaining a confidence interval for the ratio of two normal means. Standard normal theory, the delta and bootstrap methods are used to estimate the standard error of the estimate of the origin of DNA replication, as well as the variation of the replication rate.     

Interleukin-2 in the pathogenesis of perinatal white matter damage

Proinflammatory cytokines were reported to be implicated in the pathogenesis of perinatal white matter lesions. The authors document for the first time the in situ detection of interleukin-2 and interleukin-2 receptor (IL-2R) in these human white matter lesions. These results suggest that interleukin-2, reported to be toxic to oligodendrocytes and myelin, could play a role in the molecular cascade leading to white matter damage in periventricular leukomalacia.     

Serum total cholesterol and ferritin and blood haemoglobin concentrations in primary schoolchildren

Serum total cholesterol and ferritin and haemoglobin concentrations were measured in blood samples obtained by venepuncture in 378 of 593 children aged 5-6 or 8-9 years from seven primary schools in Canterbury. This study formed part of an investigation to assess the feasibility of including a venepuncture procedure for monitoring purposes in primary schoolchildren. Although only one child had a very low haemoglobin concentration of 61 g/l, a large percentage, 25% in the rising 6 years and 7% in the rising 9 years, had concentrations between 100 and 115 g/l--that is, less than the reference fifth centile. Eight per cent had a serum ferritin concentration less than 8 micrograms/l. Cholesterol concentrations higher than 5.2 mmol/l were found in 20% of the 5-6 year olds and 23% of the 8-9 year olds, and in 19% of boys and 25% of girls. About 5% of children had cholesterol concentrations above 6 mmol/l. The number of children with anaemia, iron deficiency, and high cholesterol raises serious concerns about the nutritional and coronary heart disease risk of British children.     

Early ("prophylactic") oophorectomy and adrenalectomy in carcinoma of the breast: a ten-year follow-up

Early “prophylactic” oophorectomy and adrenalectomy has been performed on 12 patients with carcinoma of the breast. The patients selected were considered to have a very bad prognosis on account of axillary node involvement associated with internal mammary chain deposits (9 patients), supraclavicular nodes (2 patients) and a parasternal mass (1 patient). Five patients had evidence of spread beyond the primary lymph drainage area (axillary and internal mammary nodes), and all had died within 4 years. In 7 patients the disease was confined to the primary lymph drainage area and 4 lived for more than 10 years, 3 being alive and well at 11 to 12 years. This is a higher proportion than in a control series but does not quite reach the level of statistical significance. In the 7 patients with disease confined to the axillary and internal mammary nodes prognosis was not apparently related to malignancy determined histologically, but did have an association with the extent of invasion of the axillary nodes. Urinary oestrogen estimations performed in 4 patients did not give any evidence that outcome was related to persistence of oestrogen production. Details of the patients'' management and replacement therapy are given and from prolonged personal follow-up of these patients it is concluded that women who have undergone oophorectomy and adrenalectomy are able to lead full and active lives.