Neonatal subgaleal haematoma: Associated risk factors, complications and outcome

Objective : To describe the obstetric and perinatal factors, in particular the method of delivery, associated with development of a subgaleal haematoma (SGH) and to determine the outcome of survivors with this type of birth trauma. Methodology : Perinatal and obstetric data were retrospectively reviewed for 37 infants admitted to the neonatal unit of the sole tertiary paediatric referral hospital in Western Australia with an SGH, over a 24 year period from 1970 to 1993. These data were compared to data for all Western Australian births. The long-term outcome was obtained through medical and private paediatric records for 26 of these infants. Results : All except one of the neonates had instrumental deliveries; 89% had a vacuum extractor applied to the head at some stage of delivery compared to 10% of the general population of births in Western Australia. There was also a significantly increased risk of failure of attempted vacuum extraction. Of the cases where a vacuum extraction was attempted, 45% also had forceps applied to the head. Coagulopathy was associated with the severity of the SGH. There was also a high frequency of occurrence (40%) of associated head trauma such as intracranial haemorrhage, skull fracture and cerebral oedema, as well as neonatal encephalopathy (73%). The occurrence of these associated features did not correlate significantly with the severity of SGH. Minor complications of SGH included jaundice and facial bruising. There was an excess mortality associated with SGH; however, the long-term outcome for neonatal survivors with this disorder was good. None of the cases studied subsequently developed cerebral palsy or intellectual disability, and minor neurological sequelae only were documented in four infants. Conclusions : SGH is an uncommon type of birth trauma, and is associated with delivery or attempted delivery by vacuum extraction. The most commonly associated clinical problems were hypovolaemia and coagulopathy. The long-term outcome for neonates with this condition is good.     

The theory/practice 'gap': taking issue with the issue

Theory/practice issues have a long-standing history in nurse education, and are a chronic source of controversy to which there is no easy or perfect solution We have argued that it is the tension between theory and practice and research which can be usefully exploited in teaching and research Students need to be introduced to the debates surrounding the genesis and generation of nursing knowledge They need to gain an appreciation of what counts as nursing knowledge at different points in time and the politics which drive the legitimation of nursing theory and practice Such an approach has much to offer in helping students deal with reality shock and make sense of their experience as they confront the ambiguities, uncertainties and contradictions that characterize the stock-in-trade of professional life     

A randomised controlled trial to determine the effect on response of including a lottery incentive in health surveys [ISRCTN32203485]

Background

Postal questionnaires are an economical and simple method of data collection for research purposes but are subject to non-response bias. Several studies have explored the effect of monetary and non-monetary incentives on response. Recent meta-analyses conclude that financial incentives are an effective way of increasing response rates. However, large surveys rarely have the resources to reward individual participants. Three previous papers report on the effectiveness of lottery incentives with contradictory results. This study aimed to determine the effect of including a lottery-style incentive on response rates to a postal health survey.

Methods

Randomised controlled trial. Setting: North and West Birmingham. 8,645 patients aged 18 or over randomly selected from registers of eight general practices (family physician practices). Intervention: Inclusion of a flyer and letter with a health questionnaire informing patients that returned questionnaires would be entered into a lottery-style draw for £100 of gift vouchers. Control: Health questionnaire accompanied only by standard letter of explanation. Main outcome measures: Response rate and completion rate to questionnaire.

Results

5,209 individuals responded with identical rates in both groups (62.1%). Practice, patient age, sex and Townsend score (a postcode based deprivation measure) were identified as predictive of response, with higher response related to older age, being female and living in an area with a lower Townsend score (less deprived).

Conclusion

This RCT, using a large community based sample, found that the offer of entry into a lottery style draw for £100 of High Street vouchers has no effect on response rates to a postal health questionnaire.     

Mechanism of acute ischemic injury of oligodendroglia in early myelinating white matter: the importance of astrocyte injury and glutamate release

In developing CNS white matter (WM), the period of early myelination is characterized by a heightened sensitivity to ischemic injury. Using an in situ (isolated) preparation, we show that the mechanism of acute ischemic injury of immature WM oligodendroglial involves Ca2+ influx though non-NMDA type glutamate receptors (GluRs). The Ca2+-influx and acute cell death that was evoked by ischemic conditions (oxygen and glucose withdrawal) in identified P10 rat optic nerve oligodendroglia were blocked by removing extracellular Ca2+ or by CNQX, a selective non-NMDA GluR antagonist. The selective Na-K-Cl cotransport (NKCC) inhibitor bumetanide was also highly protective, even though NKCC expression is restricted to astrocytes in this tissue. Bumetanide largely prevented the non-NMDA GluR-mediated [Ca2+]i rise evoked by ischemia in oligodendroglia, suggesting that it interfered with ischemic glutamate release. In control WM, glutamate-like reactivity was located mainly in astrocytes and oligodendroglia identified using ultrastructural criteria. In ischemic WM, astrocyte glutamate-like reactivity was reduced, an effect countered by bumetanide. We suggest a model in which NKCC-dependent injury and release of glutamate from astrocytes activates glutamate receptors on oligodendroglia, resulting in Ca2+-influx and acute cell death.     

Optimal designs for Michaelis-Menten kinetic studies

Many reactions in enzymology are governed by the Michaelis-Menten equation. Characterising these reactions requires the estimation of the parameters K(M) and V(max) which determine the Michaelis-Menten equation and this is done by observing rates of reactions at a set of substrate concentrations. The choice of substrate concentrations is investigated by determining Bayesian D-optimal designs for a model in which residuals have a normal distribution with constant variance. Designs which focus on alternative quantities, such as K(M) or the ratio V(max)/K(M) are also considered. The effect on the optimal designs of alternative error distributions is also considered.     

The central MHC gene, BAT1, may encode a protein that down-regulates cytokine production

BACKGROUND: BAT1 belongs to the DEAD-box family of RNA-binding proteins and is encoded in the central MHC. To determine whether it affects immune responses and hence diseases influenced by MHC haplotypes, U937, THP1 and Jurkat cells were stably transfected with anti-sense DNA corresponding to exons 2-5 of BAT1 using a retroviral vector. RESULTS: Anti-sense transfectants carried anti-sense DNA and expressed anti-sense mRNA. After mitogenic stimulation, they produced higher levels of TNFalpha, IL-1 and IL-6 than equivalent cells carrying the vector alone, suggesting that BAT1 may down-regulate acute phase cytokine production. Polyclonal antibodies raised against a peptide in exon 8 of BAT1 recognized approximately 50 kDa and approximately 38 kDa proteins in all cell lines tested, including the anti-sense transfectants. Expression was localized to the nucleolus in dividing fibroblasts. However the immunochemistry may be confounded by a recently described gene, DDXL, on chromosome 19, which shares a 89% amino acid identity with BAT1. RT-PCR analyses established that BAT1 and DDXL mRNA are expressed in resting U937, THP1 and Jurkat cells. BAT1 and DDXL are divergent in the exons selected for the anti-sense study. CONCLUSIONS: BAT1 is a negative regulator of inflammation. Future studies should address how its functions relate to those of DDXL.     

Boneloc bone-cement: experience in hip arthroplasty during a 3-year period

Polymethyl methacrylate (PMMA) bone-cement was introduced in the 1960s for fixation of total hip arthroplasty replacement components. Long-term results of cement fixation for hip and knee arthroplasty have been extremely good. Although the use of PMMA bone-cement has enabled long-term survival of joint arthroplasty implants, there has been concern about aseptic loosening. This concern led to the introduction of Boneloc bone-cement (Biomet, Warsaw, IN) in the early 1990s. It was hoped that with the improved physical and chemical characteristics of Boneloc, there would be less aseptic loosening in the long-term. A clinical trial was conducted to evaluate Boneloc bone-cement in cementing the femoral component of the Bimetric total hip arthroplasty prosthesis in 33 hips in 32 patients. On follow-up, 7 stems (24%) developed definite loosening, and 3 stems (10%) were possibly loose. Of the 7 definite loose stems, 5 (17%) were revised because of increasing pain or progressive loosening. Despite the biologic advantages of Boneloc, this study suggests that the chemicals substituted in Boneloc bone-cement led to an alteration in its mechanical properties. These properties proved to be inferior to conventional PMMA bone-cement. There is possible time-dependent deterioration of mechanical properties leading to early aseptic loosening. The conventional PMMA bone-cement has stood the test of time. Research and experimental studies should continue to improve the mechanical properties of Boneloc before further human trials.     

Dietary fat, body weight, and cancer: contributions of studies in rodents to understanding these cancer risk factors in humans

Understanding diet and energy balance as risk factors for breast, colon, and other cancers requires information on the contribution of each factor and of interactions among factors to cancer risk. Rodent models for breast cancer provide extensive data on effects of dietary fat and calories, energy balance, body weight gain, and physical activity on tumor development. Analyses of the combined data from many studies have shown clearly that quality and quantity of dietary fat and energy balance contribute independently to increased mammary gland tumorigenesis. These findings were seen in female rats fed diets high in fat (35-40% of calories) compared to rats fed control diets, with approximately 10% of calories as fat (Fay and Freedman, 1997, Breast Cancer Res. Treat. 46, 215-223). The methods used permit comparison of experimental and epidemiological data, and they may be useful in extrapolating between species and developing public health recommendations. In addition to the contributions of lifetime-diet composition, intake, energy balance, and physical activity to cancer risk, there are questions about the timing and duration of alterations in these factors and about the "dose-response" characteristics of cancer risk to the factors. Endocrine mechanisms may be significant in mammary gland tumor risk, but experimental and epidemiological data indicate that cancers at other sites, such as colon and liver, also are influenced by the factors listed. Other diet and lifestyle factors that influence energy, or specifically fat, metabolism may also affect risk for cancers that are promoted by increased intake of fat and calories. Studies of separate and interactive effects of dietary fat, black tea, weight gain, and mammary gland tumorigenesis (Rogers, et al, 1998, Carcinogenesis 19, 1269-1273) have been analyzed. Using adjustment of carcinogenesis endpoints for body weight, tumor burden, and latency, they were found to be related to weight gain within treatment groups in 2 of 3 experiments.      

Intracranial abnormalities in infants treated with extracorporeal membrane oxygenation: imaging with US and CT

Findings at neuroimaging in 100 consecutive infants treated with extracorporeal membrane oxygenation (ECMO) are presented. Imaging in these infants consisted of pretreatment cranial ultrasonography (US), daily US studies while on ECMO, and follow-up cranial computed tomography (CT) after treatment. There were findings of abnormalities in 43 patients. Thirty had intracranial bleeding, often of unusual extent and distribution. Thirteen additional infants had nonhemorrhagic abnormalities alone. Bleeding considered to be major was seen in 12% of infants. Large parenchymal hemorrhages and infarcts, cerebellar hemorrhages, and diffuse edema were the most significant abnormalities, with a 50% mortality (eight of 16 patients). No lateralization was noted with respect to distribution of bleeding sites or areas of nonhemorrhagic abnormalities. US was a sensitive but imperfect screening tool for intracranial abnormalities. Abnormalities missed with US included peripheral and small parenchymal lesions, subarachnoid hemorrhage, cerebral atrophy, and sagittal sinus thrombosis.