Asian osteomalacia is determined by dietary factors when exposure to ultraviolet radiation is restricted: a risk factor model

Twenty-seven previously osteomalacic and 77 normal Asian women participated in a seven-day survey of dietary intake and daylight outdoor exposure. Individual levels of daylight outdoor exposure discriminated poorly between normal and osteomalacic women. The presence of osteomalacia was strongly related to varying degrees of vegetarianism. Lactovegetarianism (no meat, fish or egg consumption) was associated with significantly greater osteomalacic risk than ovolactovegetarianism (no meat or fish consumption). Unlike Asian rickets, high-extraction wheat cereal as chapatti was not a significant risk factor for osteomalacia in Asian women and dietary fibre was a less important risk factor than absent dietary meat, fish or egg. When exposure to ultraviolet radiation is limited, Asian osteomalacia (and Asian rickets) are determined by dietary factors.     

Double exposure: natural and artificial ultraviolet radiation exposure in beachgoers

BACKGROUND: Although the beach is a high-risk environment for ultraviolet light exposure and subsequent skin damage, little is known about beachgoer tanning habits outside the beach setting. Our purpose was to evaluate indoor tanning and additional, nonbeach sunlight exposure in a beachgoing population. METHODS: We conducted an epidemiologic survey. RESULTS: There was more use of indoor tanning salons among sunbathing beachgoers who applied little or no skin protection from the sun (50.8% [31 of 61 respondents]) compared with nonsunbathing beachgoers (22.7% [5 of 22 respondents]). In addition to increased use of tanning salons, we observed that poorly protected sunbathers tanned at locations other than the beach on a regular basis (50.8% [31 of 61 respondents]) more than nonsunbathers did (9.1% [2 of 22 respondents]). CONCLUSION: Beachgoing sunbathers often used both natural sunlight and tanning beds, subjecting themselves to two forms of ultraviolet radiation exposure.     

Low-carbohydrate diets adversely impact the skin of a mouse model of photoaging exposed to ultraviolet B radiation

The study results regarding the effects of low-carbohydrate (LC) diets remain controversial; hence further research is required to assess their safety. Here, we examined whether LC diets cause skin damage in C57BL/6J mice. Six-week-old female mice (n = 20) were fed an LC (protein/fat/carbohydrate energy ratio = 35:45:20) or control diet ad libitum for eight weeks, after which their backs were shaved, and a subset of the mice were exposed to ultraviolet B radiation thrice per week. Ultraviolet B irradiation induced wrinkle formation on the skin surface, and thickening of the epidermis, which was also noticeable in the LC diet-fed mice in the absence of ultraviolet B radiation. Meanwhile, the number of epidermal melanocytes and degree of horny layer keratosis increased in the LC diet-fed mice following ultraviolet B irradia­tion. mRNA expression analysis of the liver and skin showed decreased levels of the antioxidant enzyme superoxide dismutase 1 following ultraviolet B irradiation only in the LC diet-fed mice. Alternatively, the expression of pro-inflammatory cytokines, tumor necrosis factor-α and interleukin-1β, increased in response to ultraviolet B radiation and LC diet intake. Hence, LC diets may adversely affect skin morphology and exacerbate the effects of ultraviolet B irradiation, which may be associated with anti­oxidant dysfunction.     

The importance of social and cultural factors to nursing status

The objective of the authors was to examine nursing staff workload. The examination is based on the workload model of Robert Karasek and on the status integration theory of P. Gibbs and Walter T. Martin. As a means of examination, an open questionnaire consisting of 55 items and 76 variables was given to nurses working in different fields of health care, studying in higher education instead, or to persons with a degree in nursing (n = 465). The main concern of the authors was to attempt to identify the inconsistencies in nursing status which might come from limited decision-making freedom and high workplace requirements. In the process of statistical analysis of the data, considerable deviation was observed regarding some scales of the questionnaire. The authors emphasize that the reasons for the inconsistencies in nursing status might originate either from traditional cultural elements or from increased workload based on unclear competencies which are forced on the nurses.     

Genetic and environmental factors in the aetiology of simple goiter

The aetiology of simple goitre, affecting up to 5% of a population in iodine-sufficient areas and over 10% in endemic areas, is incompletely understood. It is generally believed that the development of simple goitre, whether endemic or sporadic, depends on complex interactions between genetic, environmental and endogenous factors. The importance of genetic factors is evident from the clustering of simple goitre within families and from a higher concordance rate for goitre in monozygotic than in dizygotic twins. Recently, studies assessing the role of specific candidate genes or genetic markers in the aetiology of simple goitre have given conflicting data in various families. However, there may well be single genes playing a major role within certain families, eg the thyroglobulin (Tg) gene, the thyroid-stimulating hormone receptor (TSHR) gene, the Na⁺/I^- symporter (NIS) gene, and the multinodular goitre marker 1 (MNG1) on chromosome 14, but the genes will vary from family to family. In addition, family and twin studies also indicate a modest to major role for environmental factors in the aetiology of simple goitre. Clearly, iodine deficiency and cigarette smoking are the most important environmental risk factors associated with the genesis of simple goitre. Other suggested risk factors include naturally occurring goitrogens, emotional stress and certain drugs and infections. Ongoing studies focus on whole-genome screening in multiplex families as well as on large population-based case-control studies. However, the possibility that simple goitre is a heterogeneous disease without a single well-defined genotype and phenotype should be left open.     

Genetic and environmental factors in the aetiology of simple goitre

The aetiology of simple goitre, affecting up to 5% of a population in iodine-sufficient areas and over 10% in endemic areas, is incompletely understood. It is generally believed that the development of simple goitre, whether endemic or sporadic, depends on complex interactions between genetic, environmental and endogenous factors. The importance of genetic factors is evident from the clustering of simple goitre within families and from a higher concordance rate for goitre in monozygotic than in dizygotic twins. Recently, studies assessing the role of specific candidate genes or genetic markers in the aetiology of simple goitre have given conflicting data in various families. However, there may well be single genes playing a major role within certain families, eg the thyroglobulin (Tg) gene, the thyroid-stimulating hormone receptor (TSHR) gene, the Na+/I- symporter (NIS) gene, and the multinodular goitre marker 1 (MNG1) on chromosome 14, but the genes will vary from family to family. In addition, family and twin studies also indicate a modest to major role for environmental factors in the aetiology of simple goitre. Clearly, iodine deficiency and cigarette smoking are the most important environmental risk factors associated with the genesis of simple goitre. Other suggested risk factors include naturally occurring goitrogens, emotional stress and certain drugs and infections. Ongoing studies focus on whole-genome screening in multiplex families as well as on large population-based case-control studies. However, the possibility that simple goitre is a heterogeneous disease without a single well-defined genotype and phenotype should be left open.     

Systemic exposure to atorvastatin between Asian and Caucasian subjects: a combined analysis of 22 studies

The aim of the present study was to determine whether there is a differing pattern of systemic exposure to atorvastatin in Asian versus Caucasian subjects by comparison of data obtained from completed pharmacokinetic studies. Pharmacokinetic data were analyzed from completed single-dose (10-80 mg) studies in Asian and Caucasian subjects. Dose normalized area under the concentration-time curve (AUC) and maximum observed concentration (Cmax) (AUC(dn) and Cmax(dn)) were obtained by dividing each value by the administered dose. Dose-per-bodyweight normalized AUC and Cmax (AUC(dn,wt) and Cmax,(dn,wt)) were obtained by dividing each value by the administered dose per unit bodyweight. Mean difference and 90% confidence intervals for Asian versus Caucasian comparisons were calculated for atorvastatin pharmacokinetic values based on the t statistic and expressed as ratios using Caucasians as the reference. Data were analyzed from 310 Asians and 579 Caucasians from 22 studies. AUC(dn) (Asian = 2.35, Caucasian = 2.06 [ng·hr·mL(-1)]/mg) and Cmax(dn) (Asian = 0.39, Caucasian = 0.40 Cmax(dn,wt)) and the equivalent dose-per-bodyweight normalized values for atorvastatin (AUC(dn,wt): Asian = 157.5, Caucasian = 156.4 [ng·hr·mL(-1)]/[mg·kg(-1)]; Cmax(dn,wt): Asian = 26.2, Caucasian = 30.3 [ng·mL(-1)]/[mg·kg(-1)]) were similar in both ethnic groups. Mean differences and 90% confidence interval for the differences fell within the limits (0.8-1.25) except for Cmax(dn,wt), for which the lower limit was slightly below 80%. No differences were noted in the systemic exposure to atorvastatin between Asian and Caucasian subjects. These data therefore demonstrate that dosing considerations in the current labels for atorvastatin are similar for Asian compared with Caucasian subjects.     

Leadership in the radiation therapy profession: The importance of understanding the potential benefits and theoretical perspectives

The incorporation of leadership concepts is at the forefront of agendas to advance the quality of patient care and innovation in many healthcare professions. In this Commentary, the authors draw upon evidence from the literature to discuss the theoretical perspectives of leadership and potential value in radiation therapy practice. For the patients to be provided with safe and high-quality treatment, continuous change and improvement are necessary. Leadership has the potential to influence behaviour change for practitioners and core organisational culture. Several leadership styles such as the transformational leadership can be applied to achieve a higher level of patient care and improve the likelihood of enhancing quality and efficiency in healthcare. These are also paramount to the success of radiation therapy practice. Hence, a higher priority should be placed on developing leadership in the Radiation Therapist (RT) workforce and educating new graduates of the potential benefits.     

The aetiology of dizziness and how to examine a dizzy patient

Dizziness embraces various sensations of spatial disorientation. A common symptom, it has been experienced by at least one third of the population by the age of 65. Peripheral causes include disorders of the labyrinth and vestibular nerve such as Ménière's disease, benign paroxysmal positional vertigo, acute vestibulopathy (vestibular neuronitis) and acoustic neuroma. The most common lesions of the central nervous system that cause dizziness are infratentorial ischaemia, mechanical trauma, multiple sclerosis and cerebellar atrophy. Other aetiological factors include intoxications, psychogenic causes, cervical problems and cardiovascular diseases. The history and physical examination are the cornerstones of the search for the cause of dizziness. The most valuable otological methods are electronystagmography and audiometry. Of the clinical neurophysiological methods, brainstem auditory evoked potentials are more useful than electroencephalography. Computed tomography and magnetic resonance imaging should be used when a CNS disorder is suspected.     

The importance of tumor glucuronidase in the activation of irinotecan in a mouse xenograft model

The anticancer drug irinotecan (CPT-11) is activated to the potent topoisomerase I inhibitor, SN-38 (7-ethyl-10-hydroxycamptothecin), by esterases. SN-38 is in turn conjugated to the inactive SN-38 glucuronide (SN-38G). The reverse reaction is mediated by beta-glucuronidases. Hence, production of SN-38 may occur through either pathway. In this study we conducted in vitro studies to examine these two reactions in neuroblastoma xenograft tumors (NB1691) and compared the rates of SN-38 production with those observed in the liver and plasma of the host SCID (severe-combined immunodeficient) mice. The rate of formation of SN-38 from CPT-11 by esterases slowed considerably during a 60-min incubation, consistent with the known deacylation-limited nature of this reaction. For xenograft tumor tissue, K(m) and V(max) values of 1.6 microM and 4.4 pmol/min/mg of protein, respectively, were observed. By comparison, these parameters were estimated to be 6.9 microM and 9.4 pmol/min/mg for mouse liver and 2.1 microM and 40.0 pmol/min/mg for mouse plasma, respectively. The formation of SN-38 from SN-38G was very pronounced in both liver and xenograft tumor tissue, in which it was nonsaturable (0.125-50 microM) and time-independent (0-60 min). The derived values of V(max)/K(m) were 0.65 microl/min/mg for the tumor and 2.12 microl/min/mg for the liver preparations. Microdialysate experiments revealed the concentrations of SN-38G and CPT-11 in tumor to be comparable. At equal substrate concentrations, production of SN-38 from SN-38G in tumor extracts was comparable with that from CPT-11. Therefore, reactivation of SN-38 in the tumor by beta-glucuronidases may represent an important route of tumor drug activation for CPT-11.     

The importance of leukotrienes in airway inflammation in a mouse model of asthma

Inhalation of antigen in immunized mice induces an infiltration of eosinophils into the airways and increased bronchial hyperreactivity as are observed in human asthma. We employed a model of late-phase allergic pulmonary inflammation in mice to address the role of leukotrienes (LT) in mediating airway eosinophilia and hyperreactivity to methacholine. Allergen intranasal challenge in OVA-sensitized mice induced LTB4 and LTC4 release into the airspace, widespread mucus occlusion of the airways, leukocytic infiltration of the airway tissue and broncho-alveolar lavage fluid that was predominantly eosinophils, and bronchial hyperreactivity to methacholine. Specific inhibitors of 5- lipoxygenase and 5-lipoxygenase-activating protein (FLAP) blocked airway mucus release and infiltration by eosinophils indicating a key role for leukotrienes in these features of allergic pulmonary inflammation. The role of leukotrienes or eosinophils in mediating airway hyperresponsiveness to aeroallergen could not be established, however, in this murine model.     

Complexity, case-mix and rehabilitation: the importance of a holistic model of illness

Rehabilitation is not cheap. It depends upon personal interactions between rehabilitation staff and the patient and their families, and salaries for staff are always expensive. Rehabilitation depends upon learning, which takes time. The more complex the problems presented by patients the more resources are likely to be needed. This editorial reviews briefly the nature of complexity, emphasizing that it encompasses both the number of factors impinging upon the outcome of interest and the non-linear nature of many of the relationships between different factors and inputs. It describes briefly the holistic biopsychosocial model of illness that underlies much rehabilitation practice and a model of the rehabilitation process, and it then considers how complexity might be measured. It concludes that measures exist, such as the INTERMED, although they can probably be improved. But evidence derived using the INTERMED already both validates the biopsychosocial model of illness, and provides a sound basis for further developments.     

The importance of funding palliative care education: a look to the future

This article outlines the position statement agreed by the Midlands Palliative Care Teachers' Professional Forum. Written by a member of the group, it includes suggestions from other members and was submitted for publication before the recent announcement of funds being available for palliative education for district nurses. The article highlights the challenges facing the adequate funding of specialist palliative care education and, in particular, for education departments within independent hospices. The statement recognizes the sensitive nature of subjects that ought to be included in palliative care education. Emphasis is placed on the provision of holistic multiprofessional and uniprofessional courses dedicated to enhancing the quality of palliative care. The article confirms the commitment of palliative care educationalists to this end and looks to continued commitment of adequate funding from NHS trusts and regions in supporting existing palliative care education and its ongoing development in response to clinical need.