Applying the transtheoretical model to the study of exercise on prescription

This study examines the application of key constructs of the transtheoretical model and an integrated perceived barrier construct to exercise behaviour. Research participants were middle-aged, sedentary, males and females (N = 393) who were referred by their general practitioner for a three-month prescription of exercise. Partial support for the use of the transtheoretical model in a UK sample was found. The decisional balance measure, in particular the cons of exercising, reflected hypothesized differences across the stages of change. However, in contrast to previous studies, scores on efficacy items were not significantly associated with stage. A potentially influential effect of barriers to exercise on different stages of behaviour was evident. Implications for recruitment, intervention and research are discussed.

Severe thrombocytopenia and patterns of bleeding in neonates: results from a prospective observational study and implications for use of platelet transfusions

OBJECTIVE

To describe patterns of clinical bleeding in neonates with severe thrombocytopenia (ST and platelet count <60 × 10(9) L(-1)), and to investigate the factors related to bleeding.

STUDY DESIGN

Seven tertiary-level neonatal units enrolled neonates (n = 169) with ST. Data were collected prospectively on all clinically apparent haemorrhages. Relationships between bleeding, platelet count and baseline characteristics were explored through regression analysis.

RESULTS

Bleeding was recorded in most neonates with ST (138/169; 82%), including 123 neonates with minor bleeding and 15 neonates with major bleeding. The most common sites of minor bleeding were from the renal tract (haematuria 40%), endotracheal tube (21%), nasogastric tube (10%) and skin (15%). Gestational age <34 weeks, development of ST within 10 days of birth and necrotizing enterocolitis were the strongest predictors for an increased number of bleeding events. For neonates with ST, a lower platelet count was not a strong predictor of increased bleeding.

CONCLUSIONS

The majority of neonates with ST bleed, although most episodes are minor. These findings establish the importance of clinical factors for bleeding risk, rather than minimum platelet count. Further studies should assess the clinical significance of different types of minor bleed for neonatal outcomes, the predictive value of minor bleeding for major bleeding and the role of platelet transfusions in preventing bleeding.

A randomized trial comparing repetitive transcranial magnetic stimulation given 3 days/week and 5 days/week for the treatment of major depression: is efficacy related to the duration of treatment or the number of treatments?

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been shown to be an effective treatment for depression. However, there has been little research to determine optimal parameters for treatment.

METHOD

This study compared two rTMS treatment regimes for the treatment of major depression. Seventy-seven participants were randomized to either spaced or daily treatment. Spaced rTMS was given 3 days/week for 6 weeks (18 treatments in total) and daily rTMS was given 5 days/week for 4 weeks (20 treatments in total). All participants were assessed at baseline and after 4 weeks of treatment. Participants in the spaced treatment group were also assessed after 6 weeks of treatment. All participants were treated at 110% of the resting motor threshold with high-frequency rTMS (10 Hz) to the left dorsolateral prefrontal cortex (DLPFC) followed by low-frequency rTMS to the right DLPFC.

RESULTS

Participants in the daily treatment group showed more improvement by week 4 than those in the spaced treatment group; however, both groups had similar improvement by treatment completion. There was significant improvement in both groups in ratings of depression and anxiety, with no significant differences between groups.

CONCLUSIONS

Our study indicates that the efficacy of rTMS is related to the number of treatments given and that spacing the treatments neither improves nor reduces efficacy.

Type I interferon signaling limits reoviral tropism within the brain and prevents lethal systemic infection

In vivo and ex vivo models of reoviral encephalitis were utilized to delineate the contribution of type I interferon (IFN) to the host’s defense against local central nervous system (CNS) viral infection and systemic viral spread. Following intracranial (i.c.) inoculation with either serotype 3 (T3) or serotype 1 (T1) reovirus, increased expression of IFN-α, IFN-β, and myxovirus-resistance protein (Mx1; a prototypical IFN stimulated gene) was observed in mouse brain tissue. Type I IFN receptor deficient mice (IFNAR^−/−) had accelerated lethality, compared to wildtype (B6wt) controls, following i.c. T1 or T3 challenge. Although viral titers in the brain and eyes of reovirus infected IFNAR^−/− mice were significantly increased, these mice did not develop neurologic signs or brain injury. In contrast, increased reovirus titers in peripheral tissues (liver, spleen, kidney, heart, and blood) of IFNAR^−/− mice were associated with severe intestinal and liver injury. These results suggest that reovirus-infected IFNAR^−/− mice succumb to peripheral disease rather than encephalitis per se. To investigate the potential role of type I IFN in brain tissue, brain slice cultures (BSCs) were prepared from IFNAR^−/− mice and B6wt controls for ex vivo T3 reovirus infection. Compared to B6wt controls, reoviral replication and virus-induced apoptosis were enhanced in IFNAR^−/− BSCs indicating that a type I IFN response, initiated by resident CNS cells, mediates innate viral immunity within the brain. T3 reovirus tropism was extended in IFNAR^−/− brains to include dentate neurons, ependymal cells, and meningeal cells indicating that reovirus tropism within the CNS is dependent upon type I interferon signaling.

Gene expression in the brain during reovirus encephalitis

Viral encephalitis remains a significant cause of morbidity and mortality throughout the world. We performed microarray analysis to identify genes and pathways that are differentially regulated during reovirus encephalitis and that may provide novel therapeutic targets for virus-induced diseases of the central nervous system (CNS). An increase in the expression of 130 cellular genes was found in the brains of reovirus-infected mice at early times post infection, compared to mock-infected controls. The up-regulation of these genes was consistent with activation of innate immune responses, particularly interferon signaling. At later times post infection, when significant CNS injury is present and mice exhibit signs of severe neurologic disease, many more (1374) genes were up-regulated, indicating that increased gene expression correlates with disease pathology. Virus-induced gene expression at late times post infection was again consistent with the activation of innate immune responses. However, additional significant pathways included those associated with cytokine signaling and apoptosis, both of which can contribute to CNS injury. This is the first report comparing virus-induced cellular gene and pathway regulation at early and late times following virus infection of the brain. The shift of virus-induced gene expression from innate immune responses at early times post infection to cytokine signaling and apoptosis at later times suggests a potential therapeutic strategy that preserves early protective responses whilst inhibiting later responses that contribute to pathogenesis.

A case of near-drowning: a case for routine cerebral monitoring

A 6-week-old infant presenting with near-drowning was medically paralysed and ventilated on admission. Status epilepticus was found on cerebral function monitoring, without which the diagnosis would have been missed or delayed for many hours. This case illustrates the value of cerebral function monitoring for patients in intensive care, where clinical signs of seizure activity are frequently masked by paralysis and sedation.

CONCLUSION

Limited availability of electroencephalogram (EEG) and cerebral function monitoring (CFM) in paediatric intensive care may inadvertently delay diagnosis and appropriate treatments and so adversely affect outcomes. We propose that round-the-clock cerebral function and/or EEG monitoring should be available in all centres that provide paediatric intensive care.

Measuring hypomania in the postpartum: a comparison of the Highs Scale and the Altman Mania Rating Scale

We examine the prevalence of hypomania on day 3 postpartum using two self-report mania scales: The Highs Scale and Altman Mania Rating Scale (AMRS). 279 women were recruited from postnatal wards and completed the questionnaires on day 3 postpartum. The scales show good correlation, however, 11% of women meet the suggested threshold for caseness on the Highs Scale and 44% on the AMRS. Hypomanic symptoms are commonly experienced in the early postpartum. Although there is some evidence that the Highs Scale might be conservative, the AMRS likely overestimates hypomania in the postpartum. The definition of what constitutes 'a case' of postnatal hypomania requires further validation against clinical interview and ability to predict variables of clinical importance. Mania scales developed in bipolar disorder populations must be specifically validated for postpartum use.

Apoptosis in animal models of virus-induced disease

Apoptosis is associated with virus-induced human diseases of the central nervous system, heart and liver, and causes substantial morbidity and mortality. Although virus-induced apoptosis is well characterized in individual cells in cell culture, virus-induced apoptosis in vivo and the role of apoptosis in virus-induced disease is not well established. This review focuses on animal models of virus-induced diseases of the central nervous system, heart and liver that provide insights into the role of apoptosis in pathogenesis, the pathways involved and the potential therapeutic implications.

Quality of life outcome measures following partial glossectomy: assessment using the UW-QOL scale

BACKGROUND

The consequences of a diagnosis of head and neck cancer and the impact of treatment have a clear and direct influence on well-being and associated quality of life (QOL) in these patients.

AIMS

To determine the QOL in head and neck cancer patients following a partial glossectomy operation.

DESIGN AND SETTING

Cross-sectional cohort study; Head and Neck Oncology Unit, tertiary referral center.

MATERIALS AND METHODS

38 patients with partial glossectomy were assessed with the University of Washington head and neck quality of life (UW-QOL) scale, version 4.

STATISTICAL ANALYSIS

Statistical analysis was performed using the Statistical Package for Social Sciences 10.0 (SPSS Inc, Chicago version III). Information from the scale was correlated using the Mann Whitney test. A P value less than/equal to 0.05 was considered as significant.

RESULTS

The mean (sd) composite score of the QOL in our series was 73.6 (16.1). The majority (71.8%) quoted their QOL as good or very good. Swallowing (n = 16, 47.1%), speech (n = 15, 44.1%) and saliva (n = 15, 44.1%) were most commonly cited issues over the last 7 days. On the other hand, the groups with reconstruction, neck dissection, complications and radiotherapy demonstrated a significant reduction of quality of life scores (Mann Whitney test, P < 0.005).

CONCLUSION

The composite score and overall QOL as assessed using the UW-QOL scale (version 4) were modestly high in our series of partial glossectomy patients. Swallowing, speech, and saliva are regarded as the most important issues. Stage of the disease, neck dissection, reconstruction, complications, radiotherapy and time since operation were seen to significantly affect domain scores.

When can group level clustering be ignored? Multilevel models versus single-level models with sparse data

OBJECTIVE

The use of multilevel modelling with data from population-based surveys is often limited by the small number of cases per level-2 unit, prompting many researchers to use single-level techniques such as ordinary least squares regression.

DESIGN

Monte Carlo simulations are used to investigate the effects of data sparseness on the validity of parameter estimates in two-level versus single-level models.

SETTING

Both linear and non-linear hierarchical models are simulated in order to examine potential differences in the effects of small group size across continuous and discrete outcomes. Results are then compared with those obtained using disaggregated techniques (ordinary least squares and logistic regression).

MAIN RESULTS

At the extremes of data sparseness (two observations per group), the group level variance components are overestimated in the two-level models. But with an average of only five observations per group, valid and reliable estimates of all parameters can be obtained when using a two-level model with either a continuous or a discrete outcome. In contrast, researchers run the risk of Type I error (standard errors biased downwards) when using single-level models even when there are as few as two observations per group on average. Bias is magnified when modelling discrete outcomes.

CONCLUSIONS

Multilevel models can be reliably estimated with an average of only five observations per group. Disaggregated techniques carry an increased risk of Type I error, even in situations where there is only limited clustering in the data.