Literature Focus

Literature focus is a feature consisting of short abstracts highlighting recent developments of interest in the literature selected
by postgraduate researchers.

A statistical analysis of circumstellar material in Type Ia supernovae

A key tracer of the elusive progenitor systems of Type Ia supernovae (SNe Ia) is the detection of narrow blueshifted time-varying Na I D absorption lines, interpreted as evidence of circumstellar material surrounding the progenitor system. The origin of this material is controversial, but the simplest explanation is that it results from previous mass-loss in a system containing a white dwarf and a non-degenerate companion star. We present new single-epoch intermediate-resolution spectra of 17 low-redshift SNe Ia taken with XShooter on the European Southern Observatory Very Large Telescope. Combining this sample with events from the literature, we confirm an excess (∼20 per cent) of SNe Ia displaying blueshifted narrow Na I D absorption features compared to redshifted Na I D features. The host galaxies of SNe Ia displaying blueshifted absorption profiles are skewed towards later-type galaxies, compared to SNe Ia that show no Na I D absorption and SNe Ia displaying blueshifted narrow Na I D absorption features have broader light curves. The strength of the Na I D absorption is stronger in SNe Ia displaying blueshifted Na I D absorption features than those without blueshifted features, and the strength of the blueshifted Na I D is correlated with the B − V colour of the SN at maximum light. This strongly suggests the absorbing material is local to the SN. In the context of the progenitor systems of SNe Ia, we discuss the significance of these findings and other recent observational evidence on the nature of SN Ia progenitors. We present a summary that suggests that there are at least two distinct populations of normal, cosmologically useful SNe Ia.

Adherence to oral chemotherapy: a review of the literature

Oncology is rapidly changing. Over the past few years there has been an increase in the number of patients receiving oral chemotherapy, which is often administered as tablets away from the hospital setting and in the absence of direct health professional support. This situation places onus on patients to not only administer their medication, but also to report any deterioration in their health. Medication adherence in oral chemotherapy is therefore a major concern. This article examines medication adherence for people receiving oral chemotherapy and the importance of concordant communication practices.

Lymphatic mapping and sentinel node biopsy in breast cancer

Background Sentinel lymph node biopsy is a recently developed, minimally invasive technique for staging the axilla in patients with breast cancer. It has been suggested that this technique will avoid the morbidity associated with more extensive axillary dissection. A wide range of different methods and materials has been employed for lymphatic mapping, but there has been little consensus on the most reliable and reproducible technique.

Methods This is a comprehensive review of all published literature on sentinel node biopsy in breast cancer, using the Medline and Embase databases and cross-referencing of major articles on the subject.

Results and conclusion Sentinel node biopsy is a valid technique in breast cancer management, providing valuable axillary staging information. The optimal technique of lymphatic mapping utilizes a combination of vital blue dye and radiolabelled colloid. However, there remain controversial issues which require to be resolved before sentinel node biopsy becomes a widely accepted part of breast cancer care.

Supported decision making: a review of the international literature

Supported decision making (SDM) refers to the process of supporting people, whose decision making ability may be impaired, to make decisions and so promote autonomy and prevent the need for substitute decision making. There have been developments in SDM but mainly in the areas of intellectual disabilities and end-of-life care rather than in mental health. The main aim of this review was to provide an overview of the available evidence relevant to SDM and so facilitate discussion of how this aspect of law, policy and practice may be further developed in mental health services. The method used for this review was a Rapid Evidence Assessment which involved: developing appropriate search strategies; searching relevant databases and grey literature; then assessing, including and reviewing relevant studies. Included studies were grouped into four main themes: studies reporting stakeholders’ views on SDM; studies identifying barriers to the implementation of SDM; studies highlighting ways to improve implementation; and studies on the impact of SDM. The available evidence on implementation and impact, identified by this review, is limited but there are important rights-based, effectiveness and pragmatic arguments for further developing and researching SDM for people with mental health problems.

Fabricated or Induced Illness in Children: A Narrative Review of the Literature

Although child maltreatment due to abuse or neglect is pervasive within our society, less
is known about fabricated or induced illness by carers (FII), which is considered to be a
rare form of child abuse. FII occurs when a caregiver (in 93% of cases, the mother)
misrepresents the child as ill either by fabricating, or much more rarely, producing
symptoms and then presenting the child for medical care, disclaiming knowledge of the
cause of the problem. The growing body of literature on FII reflects the lack of clarity
amongst professionals as to what constitutes FII, the difficulties involved in diagnosis,
and the lack of research into psychotherapeutic intervention with perpetrators. This lack
of clarity further complicates the identification, management and treatment of children
suffering from FII and may result in many cases going undetected, with potentially lifethreatening
consequences for children. It has been suggested that there is a national
under-reporting of fabricated or induced illness. In practice these cases are encountered
more frequently due to the chronic nature of the presentations, the large number of
professionals who may be involved and the broad spectrum including milder cases that
may not all require a formal child protection response. Diagnosis of fabricated disease
can be especially difficult, because the reported signs and symptoms cannot be confirmed
(when they are being exaggerated or imagined) or may be inconsistent (when they are
induced or fabricated). This paper highlights and discusses the controversies and
complexities of this condition, the risks to the child and how it affects children; the
paucity of systematic research regarding what motivates mothers to harm their children
by means of illness falsification; how the condition should be managed and treated for
both mother and child; and implications for policy and practice.

Parents' experiences of caring for their infant following surgery in the neonatal period: A literature review

Previous research with parents of preterm and low-birth weight infants admitted to the Neonatal Intensive Care Unit (NICU) has indicated the following: (i) parents are at risk of experiencing stress associated with the NICU environment; (ii) parents are at risk of short- and longer-term psychological distress; and (iii) the family is at risk of longer-term stress and strain. However, parents of infants admitted to the NICU for surgery are an under-researched population. This paper provides an overview of the current literature in relation to this issue. The results highlight the paucity of research conducted with parents of infants admitted to the NICU for surgery. A number of gaps and limitations were also identified in the current literature, including a lack of examination why some parents cope better than others, and a focus solely on parents of preterm and low birth weight infants. To conclude, further research with parents of infants who had surgery in the first few weeks of life is needed. Such information could help inform clinicians caring for these infants and their families, and would enable identification of those parents and families most at risk.

The potential role of fruit and vegetables in aspects of psychological well-being: a review of the literature and future directions

The objective of the present paper was to review the literature investigating the potential relationship between fruit and vegetables (FV) and psychological well-being. The rising prevalence of mental ill health is causing considerable societal burden. Inexpensive and effective strategies are therefore required to improve the psychological well-being of the population, and to reduce the negative impact of mental health problems. A growing body of literature suggests that dietary intake may have the potential to influence psychological well-being. For example, studies have suggested that particular dietary constituents, including vitamins and minerals, might be beneficial to psychological health. However, in order to better reflect normal dietary intake, health-based research has increasingly begun to focus on whole foods and dietary patterns, rather than individual nutrients. One food group that has received increasing attention with regard to psychological health is FV. This is probably a result of the strong evidence base, which exists in relation to their protective association with a number of chronic diseases, as well as the fact that they are a rich source of some of the nutrients which have been linked to psychological health. While some promising findings exist with regards to FV intake and psychological well-being, overall, results are inconsistent. Possible reasons for this, such as methodological issues related to study design and the measurement of psychological well-being and FV intake, are discussed within this review. Based on the predominantly observational nature of existing literature, the present paper concludes that future well-designed randomised controlled trials are required to investigate the relationship further.