Circadian rhythms, melatonin and depression.

The master biological clock situated in the suprachiasmatic nuclei of the anterior hypothalamus plays a vital role in orchestrating the circadian rhythms of multiple biological processes. Increasing evidence points to a role of the biological clock in the development of depression. In seasonal depression and in bipolar disorders it seems likely that the circadian system plays a vital role in the genesis of the disorder. For major unipolar depressive disorder (MDD) available data suggest a primary involvement of the circadian system but further and larger studies are necessary to conclude. Melatonin and melatonin agonists have chronobiotic effects, which mean that they can readjust the circadian system. Seasonal affective disorders and mood disturbances caused by circadian malfunction are theoretically treatable by manipulating the circadian system using chronobiotic drugs, chronotherapy or bright light therapy. In MDD, melatonin alone has no antidepressant action but novel melatoninergic compounds demonstrate antidepressant properties. Of these, the most advanced is the novel melatonin agonist agomelatine, which combines joint MT1 and MT2 agonism with 5-HT(2C) receptor antagonism. Adding a chronobiotic effect to the inhibition of 5-HT(2C) receptors may explain the rapid impact of agomelatine on depression, since studies showed that agomelatine had an early impact on sleep quality and alertness at awakening. Further studies are necessary in order to better characterize the effect of agomelatine and other novel melatoninergic drugs on the circadian system of MDD patients. In summary, antidepressants with intrinsic chronobiotic properties offer a novel approach to treatment of depression.

Breeding system and factors limiting fruit production in the nectarless orchid Broughtonia lindenii.

Low fruit set values in most orchids (especially epiphytic and tropical species) are normally thought to be the consequence of pollination constraints and limited resources. In particular, pollination constraints are modulated by pollinator visitation rates, pollinator visitation behaviour (promoting crossing or selfing), the type and number of pollinia deposited on stigmas (in the case of orchids with subequal pollinia) and the amount of pollen loaded per inflorescence. In order to assess to what extent these factors can affect fruit set in specific orchid-pollinator systems, the repercussions of some of these aspects on reproduction of Broughtonia lindenii were examined in a coastal population in western Cuba. The study focused on plant breeding system, importance of pollen load and type of pollinia on subsequent fruit and seed, limiting factors of seed production and interaction with pollinators. This species presents long-lasting flowers that senesce after all forms of effective visit. Pollinator dependence for fruit production was demonstrated, while hand-pollination experiments revealed self-compatibility and inbreeding depression at seed level. More pollinia on stigmas enhance the proportion of well-developed seeds. In contrast, the pollinia type used in pollination is not important for seed quality of fruits, suggesting that small pollinia are not rudimentary. Natural fruit set in two consecutive years was substantially affected by pollinator activity, and also by systematic depredatory activity of ants and a caterpillar. Considering that this orchid completely lacks nectar and that the local assemblage of pollinators and predators influenced its reproduction, a minor importance of resource constraints in this epiphyte (with long-lasting reserve structures) is confirmed at least for a short time.

Tratamiento de la dermatitis atópica. Una perspectiva desde la medicina basada en pruebas / No disponible

En este artículo se resumen las principales intervenciones utilizadas para el tratamientoy prevención de la dermatitis atópica (DA). Para ello, se han revisado bases dedatos secundarias y guías de práctica clínica de buena calidad metodológica con el objetivode ofrecer una visión general de la eficacia de estas medidas. Para la redacción deeste artículo se han utilizado principalmente dos recursos, Clinical Evidence y la guía depráctica clínica de NICE. Se ha complementado su información, cuando se ha estimadopreciso, con otras fuentes de información, principalmente revisiones sistemáticas de laColaboración Cochrane(AU)

This article summarizes the most important interventions used in the treatment andprevention of atopic dermatitis (DA). Secondary databases and good methodological qualityclinical guidelines have been reviewed in order to offer a general overview of the availableevidence of these measures. Two resources have mainly been used: Clinical Evidenceand the clinical guideline NICE.Its information has been completed, when necessary, with other information resources,mainly systematic reviews of the Cochrane Collaboration(AU)

[The Andalusia Epilepsy Society's Guide to Epilepsy Therapy 2005: IV. General principles of antiepileptic polytherapy and therapeutic strategies in refractory epilepsy]. / Guía terapéutica en epilepsia de la Sociedad Andaluza de Epilepsia 2005: IV. Principios generales de politerapia antiepiléptica y estrategias terapéuticas en epilepsia refractaria.

AIMS: The objective of this work was to produce a scientific evidence-based guide to clinical practice dealing with the basic questions concerning the treatment of epilepsy. DEVELOPMENT: A committee of 11 experts belonging to the Andalusia Epilepsy Society, made up of six neurologists, three neuropaediatricians, one neurosurgeon and a pharmacologist, all of whom were deeply involved and experienced in epilepsy, conducted a thorough review of the literature in search of all the evidence available on the proposed subject matter. The following databases were used: MEDLINE, Cochrane Library and the databases of several clinical practice guidelines (National Guideline Clearinghouse, National Institute of Clinical Excellence and the American Academy of Neurology's Clinical Guidelines). The Guide was set out in seven sections and was published in four parts. From a total number of 187 relevant documents, the committee found 63 examples of scientific evidence and 91 therapeutic recommendations. These were tabulated and classified according to the European Federation of Neurological Societies' criteria for producing Clinical Practice Guidelines. CONCLUSIONS: The results of this survey provide scientific evidence-based clinical guidelines that are useful, simple and applicable at different levels of health care.

Argentine plants as potential source of insecticidal compounds.

CH2Cl2 and MeOH extracts of 15 Argentine plants used locally as insecticides, were evaluated for their insecticidal activity. Chenopodium multifidum L. (Chenopodiaceae); Flaveria bidentis (L.) O.K. (Compositae); Aristolochia argentina Gris. (Aristolochiaceae) and Tagetes erecta L. (Compositae) showed a significant activity against Sitophilus oryzae.

Biological evaluations of commercial dicalcium phosphates as sources of available phosphorus for broiler chicks.

One thousand male Hubbard chicks were used in a 21-d study (10 birds per battery cage) to determine relative biological availability of phosphorus in seven samples of commercial dicalcium phosphate, expected to contain variable amounts of monocalcium phosphate. Five samples were from established producers in Brazil and two from the U.S. Pure calcium phosphate dibasic dihydrate was used as the reference standard. Phosphates were added to the corn-soybean basal diet (22.5% CP; 0.4% total phosphorus) to provide 0.1, 0.2, and 0.3% supplemental phosphorus. The calcium level was 1.0% for all diets. Left tibias were removed for bone ash (BA) and bone strength (BS) determination. Body weight, feed intake (FI), BA, BS, and plasma phosphorus increased (P < 0.01) and plasma calcium and alkaline phosphatase decreased (P < 0.01) with increasing dietary phosphorus regardless of source. The availability of phosphorus for each test phosphate was determined by slope ratio, with BW, BA, and BS regressed on phosphorus added within each phosphorus source. A relative biological value (RBV) was calculated based on BW, BA, and gain:feed ratio. Availability based on BW ranged from 97.07 to 110.41%. When BA was the criterion, values were 80.32 to 107.84% and for BS were 79.34 to 110.52%. The RBV ranged from 97.55 to 100.60%. Phosphate sources did not vary greatly in phosphorus availability. Overall phosphorus availability averages were higher for BW (103%) and RBV (99%) and lowest for BA (96%) and BS (94%).