Increasing radiant heat flux affects leaf flammability patterns in plant species of eastern Australian fire-prone woodlands.

Leaf flammability is a functional trait that can vary widely among plant species. At present, however, the effects that increasing radiant heat flux have on variation in leaf flammability among species are not well understood. Yet, such effects could have important implications for wildfire models that take into account species' differences in flammability. We examined how five leaf flammability attributes spanning ignitibility (times to incandescence and flaming), sustainability (incandescence and flame durations) and combustibility (proportion of leaves entering flaming combustion) responded to increasing radiant heat fluxes (29.6 to 96.6 kWm-2 ) in 10 species of fire-prone woodlands. As radiant heat flux increased, times to incandescence and flaming became significantly faster and proportions of leaves entering flaming combustion became significantly higher. In contrast, incandescence duration became significantly shorter at high radiant heat flux. Differences among species in these flammability attributes decreased with increasing radiant heat flux, with species becoming significantly more similar to each other. Differences among species in flame duration, however, were not significantly affected by increasing radiant heat flux, with leaf flaming durations in each species remaining relatively fixed across the radiant heat flux gradient. Our findings show that leaf flammability is significantly affected by increasing radiant heat flux. We suggest that of the flammability attributes assessed in our study, flame duration is the most informative to include in wildfire models which explicitly consider species' flammability, given that differences among species in flame duration are maintained across a radiant heat flux gradient.

Clinical selection criteria can predict futile intervention in patients referred for percutaneous endoscopic gastrostomy insertion.

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) placement is performed in a patient group with high mortality in the short and medium term. For a significant proportion of patients, the procedure provides no increase in survival. There are no standardised assessment tools available to determine the clinical appropriateness of PEG placement, nor any to predict clinical outcome. AIM: The study aims to determine whether clinical assessment, by a trained dietitian, of the appropriateness of PEG placement is predictive of mortality in the short and medium terms. METHODS: A prospective audit was undertaken of all requests for PEG placement at a single large, publicly funded Australian tertiary hospital. The clinical appropriateness of each request was assessed by a trained dietitian, and data on age, sex, reason for referral, comorbidities and satisfaction of assessment criteria were collected, and patient outcome and survival were compared for all patients according to whether a PEG was inserted or not. Main outcome measures were mortality at 30 and 150 days after referral. RESULTS: During the period 2005-2008, 198 patients were referred for PEG; 94 were assessed as appropriate referrals, 104 as inappropriate. Eighty-four patients who underwent gastrostomy, after being assessed as appropriate, had significantly reduced mortality at 30 days (96.4% vs 74.6%, P < 0.0001) and 150 days (82.1% vs 57.9%, P = 0.0001) compared with all other patients. Patients who received PEG despite contrary advice had no significant survival advantage, at 30 days or 150 days, over patients who did not receive PEG. CONCLUSION: The application of selection criteria by trained assessors improves patient selection for PEG insertion and predicts mortality at early and later time points, by identifying patients unlikely to benefit from PEG. The group of patients who received a gastrostomy despite an adverse assessment had no mortality benefit - in these patients, the procedure may have been futile.

Asthma and suicide-related adverse events: a review of observational studies.

Suicide is a major public health concern. There are several risk factors associated with suicide. Chronic illnesses, such as asthma, have been linked to an increased risk of suicide-related events. This study reviews the evidence of an association between asthma and suicide using published epidemiological observational studies. An electronic search using PubMed and EMBASE was performed. Studies that investigated the association of asthma with suicide-related behaviour were selected. Studies were examined to form a descriptive analysis. Six observational studies met the selection criteria, of which at least one suicide-related adverse event was studied. Three studies investigated completed suicide, two suicide attempts and four suicide ideation. Two of the studies focused on individuals aged <18 yrs. Evidence from observational data support the hypothesis of an association between asthma and suicide-related behaviour (ideation, attempts and completion); however, epidemiological studies, with more objective measures and larger sample sizes, adjusting for a wider scope of suicide-related confounding factors (e.g. comorbidities), and with a longitudinal design, are needed for a more conclusive answer.

Changing trends in antiepileptic drug prescribing in girls of child-bearing potential.

OBJECTIVE: To characterize trends in prescribing carbamazepine (CBZ), sodium valproate (VPA) and lamotrigine (LTG) in adolescent females in the UK and to examine possible reasons for changing trends. DESIGN: Population-based observational study. SETTING: UK General Practice Research Database between 1 January 1993 and 31 December 2006. PATIENTS: 12-18-year-old subjects who were issued >or=1 CBZ, VPA or LTG prescription. MAIN OUTCOME MEASURES: Prescribing prevalences stratified by age, gender and antiepileptic drug. RESULTS: 5417 patients (47.6% females) were prescribed 147 111 prescriptions for CBZ (34.5%), VPA (38.6%) or LTG (26.9%). The prevalence of LTG prescribing in females increased from 0.08 (95% CI 0.04 to 0.12) to 0.80 (95% CI 0.70 to 0.89) per 1000 female population. Conversely, the prevalence in females of CBZ and VPA prescribing significantly decreased from 1.00 (95% CI 0.85 to 1.15) to 0.51 (95% CI 0.44 to 0.58) and from 0.94 (95% CI 0.80 to 1.09) to 0.63 (95% CI 0.55 to 0.72), respectively. This 10-fold rise in LTG prescribing in females is much higher than the fivefold rise in males from 0.09 (95% CI 0.05 to 0.14) to 0.47 (95% CI 0.40 to 0.54) per 1000 male population. CONCLUSION: The practice of prescribing antiepileptic drugs in adolescents has changed gradually over the last decade. More females aged 12-18 years are prescribed LTG than CBZ or VPA and the increase is much greater than for males. The increase in LTG prescribing mirrors a corresponding decrease in both VPA and CBZ. Concerns about potential problems to offspring appear to be affecting prescription trends in adolescent females of child-bearing potential.

Relationship of psoriasis severity to obesity using same-gender siblings as controls for obesity.

BACKGROUND: Psoriasis is a multifactorial disease affected by both genetic and environmental factors. Several comorbid conditions, such as smoking, depression and obesity have been found to be associated with psoriasis. This study addressed the association of psoriasis and obesity using same-gender full siblings as controls, correlating between body mass index (BMI) and severity of psoriasis as determined by body surface area (BSA) and the Physician's Global Assessment (PGA). METHODS: In total, 88 patients undergoing outpatient treatment for psoriasis were surveyed for demographic information, psoriasis history, social history, personal and family medical history, whether they had a same-gender full sibling and if so, the age, weight and height of the sibling. Height, weight, PGA scores and percentage of BSA affected by psoriasis, were recorded for each patient. BMI was calculated for each patient and their same-gender full sibling. RESULTS: A positive association between psoriasis severity and BMI was found. PGA score increased with BMI (Spearman's correlation, r(s) = 0.29, P = 0.007). There was also a positive correlation between BMI and BSA%, r(s) = 0.24, P = 0.02. A significant difference in BMI between patients with psoriasis and the same-gender full sibling control was seen for women (mean +/- SD 30.2 +/- 10.2 vs. 27.6 +/- 7.3 kg/m(2), respectively, P = 0.02), but not for men. CONCLUSION: In this study, psoriasis severity was found to be related to the level of obesity. Using same-gender siblings as genetic controls for predisposition to both obesity and psoriasis, patients with psoriasis were more likely to have a higher BMI, particularly for women. This study reinforces the need to treat the whole patient and to encourage healthy living, such as maintaining an appropriate weight, proper eating habits and exercise. Limitations of this study include the relatively small number of patients enrolled, potential inaccuracies in sibling BMIs calculated from information provided by patients, and a lack of information about dietary habits, exercise and lifestyle.

Mycophenolate mofetil therapy for moderate to severe atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory disease of the skin that can be refractory to topical and systemic corticosteroids, phototherapy, topical immunomodulators and systemic immunosuppressive drugs. Recent studies have shown promise for the use of mycophenolate mofetil (MMF) to treat recalcitrant AD. AIM: To assess the effectiveness and adverse effects of MMF used for moderate to severe AD in a university outpatient dermatology clinic. METHODS: A retrospective chart review of 20 patient charts was conducted for patient age, gender, duration of disease, prior therapies, concomitant therapy, clinical response and adverse side-effects. RESULTS: Of the 20 patients, 17 improved within 4 weeks of starting MMF therapy. Ten patients had disease remission and were subsequently able to discontinue MMF. Seven attained satisfactory control of their AD using MMF as maintenance therapy. Overall, MMF was well tolerated, with mild headaches, gastrointestinal complaints and fatigue as the commonest side-effects. During therapy, herpes zoster developed in four patients, Staphylococcus aureus cutaneous infections in two, and herpes simplex in one. One patient discontinued MMF because of insufficient control of pruritus. CONCLUSION: MMF can be rapidly effective and well tolerated in patients with moderate to severe AD resistant to conventional therapies. The limitations of this retrospective study include no control group and a lack of a standardized scoring index to assess improvement, and the concomitant use of adjuvant therapies makes the contribution of MMF alone difficult to assess. Larger controlled studies are needed.

A drug utilisation study of antidepressants in children and adolescents using the General Practice Research Database.

AIMS: To characterise prescribing patterns of antidepressants (ATDs) to children and adolescents aged < or =18 years in the UK. METHODS: Subjects issued at least one ATD prescription between 1 January 1992 and 31 December 2001 were identified from the UK General Practice Research Database. Prescribing patterns, annual prevalence, morbidity patterns, and time to discontinuation of ATD use were identified. RESULTS: A total of 24,976 subjects received 93,091 prescriptions; 51,868 (55.7%), 38,429 (41.3%), and 2708 (2.9%) prescriptions were for tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), and other ATDs respectively. ATD prevalence increased 1.7-fold from 1992 to 2001. TCA prevalence decreased by 30% from 3.6 to 2.5 per 1,000; SSRI prevalence increased 10 times from 0.5 to 4.6 per 1,000. In new ATD users aged < or =10 years, the most common diagnosis associated with TCA use was nocturnal enuresis (75.1%); in those aged > or =15 years, it was depression (45.8%). Depression was also associated with SSRI use (69.0%). For new users with depression, the median treatment durations for TCAs and SSRIs were 30 and 58 days respectively. TCA users were more likely to terminate treatment than SSRI users (TCAs v fluoxetine: 1.40, 95% CI 1.32 to 1.47; non-fluoxetine SSRIs v fluoxetine: 1.01, 95% CI 0.96 to 1.07). CONCLUSIONS: SSRIs have gained popularity for the treatment of depression compared with TCAs. TCAs are still used despite their lack of efficacy in prepubertal depression and their moderate effect in adolescents. However, >50% of subjects discontinue treatment after two months, with TCA users stopping earlier than SSRI users.

Increased prescribing trends of paediatric psychotropic medications.

Psychotropic medication use by children in the USA has increased. We used the IMS MIDAS Prescribing Insights to examine prescribing trends in nine countries between the years 2000 and 2002. Trends in seven countries rose significantly from year 2000 to 2002; the UK had the highest increase (68%).

Hydatid mole with a coexisting pregnancy.

Hydatid mole with a coexisting pregnancy is rare and presents a high risk for maternal and fetal morbidity and mortality. A case of hydatid mole with coexisting pregnancy that progressed to 24 weeks' gestation is presented. Maternal religious beliefs regarding pregnancy termination affected the medical plan of care. Although the woman was aware of the potential complications, pregnancy termination and karyotype testing were refused. Because of uncontrollable hemorrhage, a cesarean delivery was done. The genotypically normal fetus died 10 hours after birth. After delivery, preeclampsia, pulmonary edema, and renal failure developed in the woman, which resolved within 4 days.

Computer versus lecture: strategies for teaching fetal monitoring.

The purpose of this study was to determine how well novice nurses learned basic fetal monitoring concepts from a computer-assisted instructional program and a scripted lecture with equivalent content. A pretest-posttest experimental design was conducted. Forty-eight junior baccalaureate nursing students beginning their first maternity rotation were recruited for the study from a southwestern university. Thirty-nine students provided complete data sets. None had prior experience or education in fetal monitoring. Two strategies were used to teach basic fetal monitoring concepts: a scripted lecture with black-and-white transparencies and an equivalent computer-assisted instructional program. Statistical significance was set at p = 0.05. There were no significant differences between the computer and lecture groups' learning on the basis of age, education, or vision. There was a positive, nonsignificant gain in mean scores from the pretest to the posttest for both groups. The greatest difference was in the program completion time with the computer-assisted instruction group completing the program 43.6% faster than the lecture group.

Self-esteem, social support, and satisfaction differences in women with adequate and inadequate prenatal care.

This descriptive, retrospective study examined levels of self-esteem, social support, and satisfaction with prenatal care in 193 low-risk postpartal women who obtained adequate and inadequate care. The participants were drawn from a regional medical center and university teaching hospital in New Mexico. A demographic questionnaire, the Coopersmith self-esteem inventory, the personal resource questionnaire part 2, and the prenatal care satisfaction inventory were used for data collection. Significant differences were found in the level of education, income, insurance, and ethnicity between women who received adequate prenatal care and those who received inadequate care. Women who were likely to seek either adequate or inadequate prenatal care were those whose total family income was $10,000 to $19,999 per year and high school graduates. Statistically significant differences were found in self-esteem, social support, and satisfaction between the two groups of women. Strategies to enhance self-esteem and social support have to be developed to reach women at risk for receiving inadequate prenatal care.

Estimation of long-term risk from Canadian uranium mill tailings.

A methodology is presented for assessing the risk from Canadian uranium mill tailings piles. The methodology is based on the "set of triplets" concept and uses an event tree to identify various scenarios representing the performance of a pile over its 1,000-year design life. Compartment-type mathematical models are used to quantify the movement of hazardous substances through the environment. Numerical examples are given of both "level 1" (straight probabilistic) and "level 2" (probability of frequency) type analyses.

Mutagenic activity from nitrosation of oligoamines.

To determine structural features necessary for the production of direct mutagenic activity from oligoamine-nitrate reaction mixtures, we systematically tested a group of aliphatic amine substrates for comutagenic action with nitrite. The ability to react with nitrite and form direct-acting mutagenic derivatives was common to a reasonably well defined class of aliphatic polyamines. In general, primary-secondary diamino compounds were mutagenic in the Ames Salmonella tester system when reacted with nitrite, whereas primary and secondary amines produced no direct mutagenic activity when tested separately. In combination with teritary amino groups, primary amines were inactive; one secondary-tertiary amine was tested, and this substrate produced mutagenic activity.

Interaction of mutagenic spermidine-nitrous acid reaction products with uvr- and recA-dependent repair systems in Salmonella.

It has been observed previously that the mutagenic action of nitrous acid may be potentiated by polyamines. We examined the cellular response of two deoxyribonucleic acid repair systems to treatment with spermidine-nitrite reaction products. uvrB- deficient mutants of Salmonella typhimurium LT2 showed enhanced lethal and mutagenic response to the reaction products. Lethal activity was further enhanced in a uvrB recA double mutant, whereas mutagenic activity was not detectable. Dependence of mutagenesis on the recA gene implicates the action of an error-prone repair system in the fixation of a premutagenic lesion as a mutation. From consideration of the substrate characteristics of the two repair systems studied, it is suggested that the deoxyribonucleic acid lesion formed by the reaction products of spermidine and nitrite is an intrastrand cross-link.