Dermoscopy, a useful tool for general practitioners in melanoma screening: a nationwide survey.

BACKGROUND: Dermoscopy improves diagnostic accuracy in melanoma, as shown by several meta-analyses. Although it is used by general practitioners (GPs) in Australia, Canada and Italy, no published data on this topic are available in France. OBJECTIVES: To review the opinions and use of dermoscopy by GPs in France and to understand their practice of skin examination. METHODS: We designed a descriptive and cross-sectional survey and conducted it between 26 November and 26 December 2014. An anonymous, multiple-choice questionnaire about the demographic characteristics, skin examination modalities and use and training in dermoscopy was sent to 4057 GPs in four large regions of France. Pearson, χ(2) , Student, Welch and Fisher tests were used for cross-tabulation statistical analysis. RESULTS: Only 8% of respondents had access to a dermoscope; most were male practitioners and aged > 50 years. Dermoscopy increased self-confidence in analysing pigmented lesions (P = 0·004), and dermoscopy users referred fewer patients to dermatologists. The number of biopsies was reduced in the dermoscopy users group (P = 0·004). In total, 425 questionnaires were returned and analysed. Dermoscopy users took more time to evaluate a single pigmented lesion (P = 0·015). Only 16·9% of physicians declared having received some training on dermoscopy, yet this number reached 47% for those owning a dermoscope. Their training was mostly short and recent. Overall 29·2% of the respondents said the main advantage was to reduce the number of referrals to the dermatologists (P = 0·004), while its main disadvantage was the necessity of training (54·6%). Our responders declared they could spend seven working days on a dermoscopy training course. CONCLUSIONS: Our study demonstrates positive opinions regarding dermoscopy, despite a minority of French GPs using this technique in the areas surveyed. The need for formal training appears to be the main limitation to wider use. Appropriate and specifically designed training programmes should be offered.

Infection by Leishmania infantum in cats: epidemiological study in Spain.

More than 40 cases of feline leishmaniasis have been reported in the scientific literature. The influence of some immunodepressive conditions of viral origin, such as leukemia and feline immunodeficiency, are still unknown. The purpose of this study was to assess the prevalence of Leishmania infection in cats and possible relations with these viral infections. Markers of Leishmania infection were searched in 183 cats from Southern Spain by IFAT, PCR, Giemsa stain and culture, with a follow-up of positive cats. Seropositivity was 60.0% (Ab titer > or =10) and 28.3% of animals presented Ab titers > or =40. Around 25.7% of the cats studied were parasitemic and some of them remained positive for months. Combining both data, 70.6% of the feline population was, or could be, infected. We observed a negative association between seropositivity to Leishmania and infection by FeLV. Hence, production of antibodies against the parasite appears to be compromised in cats with leukemia, which have a prevalence of 36% in our study. In contrast, we found no association with feline immunodeficiency. The results makes us doubt the value of conventional serological methods to detect active Leishmania infection in cats.

Abrupt climate change in the computer: is it real?

Models suggest that dramatic changes in the ocean circulation are responsible for abrupt climate changes during the last ice age and may possibly alter the relative climate stability of the last 10,000 years.

14C activity and global carbon cycle changes over the past 50,000 years.

A series of 14C measurements in Ocean Drilling Program cores from the tropical Cariaco Basin, which have been correlated to the annual-layer counted chronology for the Greenland Ice Sheet Project 2 (GISP2) ice core, provides a high-resolution calibration of the radiocarbon time scale back to 50,000 years before the present. Independent radiometric dating of events correlated to GISP2 suggests that the calibration is accurate. Reconstructed 14C activities varied substantially during the last glacial period, including sharp peaks synchronous with the Laschamp and Mono Lake geomagnetic field intensity minimal and cosmogenic nuclide peaks in ice cores and marine sediments. Simulations with a geochemical box model suggest that much of the variability can be explained by geomagnetically modulated changes in 14C production rate together with plausible changes in deep-ocean ventilation and the global carbon cycle during glaciation.

Global warming and marine carbon cycle feedbacks on future atmospheric CO2

A low-order physical-biogeochemical climate model was used to project atmospheric carbon dioxide and global warming for scenarios developed by the Intergovernmental Panel on Climate Change. The North Atlantic thermohaline circulation weakens in all global warming simulations and collapses at high levels of carbon dioxide. Projected changes in the marine carbon cycle have a modest impact on atmospheric carbon dioxide. Compared with the control, atmospheric carbon dioxide increased by 4 percent at year 2100 and 20 percent at year 2500. The reduction in ocean carbon uptake can be mainly explained by sea surface warming. The projected changes of the marine biological cycle compensate the reduction in downward mixing of anthropogenic carbon, except when the North Atlantic thermohaline circulation collapses.