Impact of Polygenic Risk for Schizophrenia on Cortical Structure in UK Biobank.

BACKGROUND: Schizophrenia is a neurodevelopmental disorder with many genetic variants of individually small effect contributing to phenotypic variation. Lower cortical thickness (CT), surface area, and cortical volume have been demonstrated in people with schizophrenia. Furthermore, a range of obstetric complications (e.g., lower birth weight) are consistently associated with an increased risk for schizophrenia. We investigated whether a high polygenic risk score for schizophrenia (PGRS-SCZ) is associated with CT, surface area, and cortical volume in UK Biobank, a population-based sample, and tested for interactions with birth weight. METHODS: Data were available for 2864 participants (nmale/nfemale = 1382/1482; mean age = 62.35 years, SD = 7.40). Linear mixed models were used to test for associations among PGRS-SCZ and cortical volume, surface area, and CT and between PGRS-SCZ and birth weight. Interaction effects of these variables on cortical structure were also tested. RESULTS: We found a significant negative association between PGRS-SCZ and global CT; a higher PGRS-SCZ was associated with lower CT across the whole brain. We also report a significant negative association between PGRS-SCZ and insular lobe CT. PGRS-SCZ was not associated with birth weight and no PGRS-SCZ × birth weight interactions were found. CONCLUSIONS: These results suggest that individual differences in CT are partly influenced by genetic variants and are most likely not due to factors downstream of disease onset. This approach may help to elucidate the genetic pathophysiology of schizophrenia. Further investigation in case-control and high-risk samples could help identify any localized effects of PGRS-SCZ, and other potential schizophrenia risk factors, on CT as symptoms develop.

Vasorelaxant and blood pressure lowering effects of alchemilla vulgaris: A comparative study of methanol and aqueous extracts.

BACKGROUND: In the last decade, a growing interest particularly in determining the cardiovascular effects of herbal extracts took place among researchers. OBJECTIVE: Herein, we aimed to investigate the microvascular and blood pressure lowering effects of two differently processed extracts of the same herb, Alchemilla vulgaris (Rosaceaea), which was revealed to contain high levels of vasoactive compounds. MATERIALS AND METHODS: For the purpose, endothelium intact rat mesenteric arteries were mounted in a myograph system and contracted with prostaglandin F2α (PGF2α: 3 × 10(-5) M) or potassium chloride (K(+): 40 mM). Then, aqueous and methanol extracts were added at 0.01-10 mg/ml concentrations in a cumulative manner. RESULTS: Both extracts produced relaxations in PGF2α (3 × 10(-5) M) precontracted arteries which were insensitive to the inhibitors of endothelium derived vasoactive substances namely, L(G)-nitro-L-arginine (10(-4) M), ODQ (10(-5) M) and indomethacin (10(-5) M) or removal of endothelium. Opposite vascular effects were observed when extracts were applied in K(+) precontracted arteries. In addition, oral administration of the methanol extract of Alchemilla vulgaris, but not the aqueous extract, reduced blood pressure significantly in L-NAME hypertensive rats. CONCLUSION: Our results demonstrated that the methanol extract of Alchemilla vulgaris has more prominent and favourable vascular effects in normal and experimental hypertensive conditions reinforcing its traditional use in cardiovascular disorders, in particular hypertension. These results most likely give rise to further studies to reveal its mechanism of action and clinical value of this herb.

Endothelium-dependent vasorelaxant effect of Alchemilla vulgaris methanol extract: a comparison with the aqueous extract in rat aorta.

We aimed to investigate the vascular effects of methanol extract (ME) and aqueous extract (AE) of Alchemilla vulgaris (Rosaceaea). Increasing concentrations of the ME (0.01-10 mg/mL) produced relaxations in noradrenaline (NA: 10⁻6 M) and K⁺ (40 mM) precontracted aortas while contractions were obtained with the AE (0.01-10 mg/mL). Responses to the ME were inhibited in the presence of putative inhibitors of endothelial vasodilators or after removal of the endothelium. Pretreatment of aortic rings with the ME (10 mg/mL, 20 min) reduced the maximal contractions to NA and K⁺, whereas an enhanced contractility was observed with the AE (10 mg/mL, 20 min). Total flavonoid content was higher in the ME than in the AE. Quercetin was determined particularly high in the ME while gallic acid was high in the AE. Our results indicated that the ME of A. vulgaris displays favourable vascular effects via endothelium-dependent mechanisms.

A meta-analysis of seaweed impacts on seagrasses: generalities and knowledge gaps.

Seagrasses are important habitat-formers and ecosystem engineers that are under threat from bloom-forming seaweeds. These seaweeds have been suggested to outcompete the seagrasses, particularly when facilitated by eutrophication, causing regime shifts where green meadows and clear waters are replaced with unstable sediments, turbid waters, hypoxia, and poor habitat conditions for fishes and invertebrates. Understanding the situations under which seaweeds impact seagrasses on local patch scales can help proactive management and prevent losses at greater scales. Here, we provide a quantitative review of available published manipulative experiments (all conducted at the patch-scale), to test which attributes of seaweeds and seagrasses (e.g., their abundances, sizes, morphology, taxonomy, attachment type, or origin) influence impacts. Weighted and unweighted meta-analyses (Hedges d metric) of 59 experiments showed generally high variability in attribute-impact relationships. Our main significant findings were that (a) abundant seaweeds had stronger negative impacts on seagrasses than sparse seaweeds, (b) unattached and epiphytic seaweeds had stronger impacts than 'rooted' seaweeds, and (c) small seagrass species were more susceptible than larger species. Findings (a) and (c) were rather intuitive. It was more surprising that 'rooted' seaweeds had comparatively small impacts, particularly given that this category included the infamous invasive Caulerpa species. This result may reflect that seaweed biomass and/or shading and metabolic by-products like anoxia and sulphides could be lower for rooted seaweeds. In conclusion, our results represent simple and robust first-order generalities about seaweed impacts on seagrasses. This review also documented a limited number of primary studies. We therefore identified major knowledge gaps that need to be addressed before general predictive models on seaweed-seagrass interactions can be build, in order to effectively protect seagrass habitats from detrimental competition from seaweeds.

What psychosocial factors influence adolescents' oral health?

Few studies have examined, comprehensively and prospectively, determinants of oral-health-related quality of life. The aim of this study was to examine the relationships between psychosocial factors and oral health status, health perceptions, and quality of life. Measures of symptom and functional status, health perceptions, quality of life, oral health beliefs, and psychological (sense of coherence, self-esteem, health locus of control) and social factors (parents' income and education) were collected from 439 12- and 13-year-olds at baseline and six-month follow-up, together with a clinical examination at baseline. Structural equation modeling indicated that increased levels of caries and more symptoms predicted more functional limitations, and, cross-sectionally, greater functional impact was associated with worse health perceptions, which were linked to lower quality of life. Sense of coherence was the most important psychosocial predictor. These factors are important in understanding how oral health affects young people's daily lives.

Expression of survivin, platelet-derived growth factor A (PDGF-A) and PDGF receptor alpha in primary central nervous system lymphoma.

PURPOSE: Primary central nervous system lymphomas (PCNSL) are rare tumours occurring in the brain. Their biology and the factors predicting survival are not well known. This study investigated expression of the antiapoptotic protein survivin and platelet-derived growth factor A (PDGF-A) and receptor (PDGFRalpha) in PCNSL. EXPERIMENTAL DESIGN: A total of 44 patients with histologically confirmed PCNSL treated between 1992 and 2004 were included in this study, and tumour specimens were investigated immunohistochemically for expression of survivin, PDGF-A and PDGFRalpha. Protein expression and clinical variables were analyzed statistically. RESULTS: Of the 44 tumours 43(98%) were diffuse large B-cell non-Hodgkin's lymphomas (NHL) and one was a T-cell NHL. Around 37 (84%) of the examined PCNSL specimens showed expression of survivin, 16 (36%) of PDGF-A and 34 (77%) of PDGFRalpha. Tumours expressing surviving co-expressed PDGFRalpha frequently and PDGF-A occasionally. Expression of the above proteins was not predictive for survival in this patient group. Except for age and therapy, no other clinical variables correlated significantly with overall survival. CONCLUSIONS: PCNSL express survivin and PDGFRalpha in the majority of investigated cases. PDGF-A is expressed less frequently. Immunohistochemical detection of these proteins does not correlate with overall survival and cannot be used as a prognostic factor.

[Mushroom poisoning in Turkey]. / Les intoxications par les champignons en Turquie.

Mushroom poisoning constitutes the main part of plant intoxications in Turkey. Not only in rural areas, but also in Istanbul, gathering mushrooms is a habit among villagers who have moved to the city and settled in the vicinity of a forest. Phalloides syndrome, Pantherina syndrome and gastro-intestinal syndrome are the most frequently encountered types of mushroom poisonings. Amanita phalloides which is growing widely in Istanbul forests is responsible for many serious cases every year. Haemoperfusion and penicillin are used for the treatment, because Legalon-SIL is not imported in Turkey.

Secondary structure model of the coat protein gene of turnip yellow mosaic virus RNA: long, C-rich, single-stranded regions.

The RNA of all tymoviruses, a group of ssRNA plant viruses, has a base composition that is different from that of most other viruses. The excess of cytosines (35-42%) and the low number of guanosines (15-17%) must impel an RNA structure with a relatively low amount of base pairing and a high incidence of unpaired cytosines. These unpaired cytosines probably function in RNA-protein interactions. To gain Insight into the way the RNA is positioned inside the virion, the secondary structure has been determined of a part of TYMV RNA, including the so-called tymobox, the coat protein gene, and the 3' untranslated region, by structure probing, sequence comparison, and computer predictions. Conservation of secondary structure elements in tymoviruses is not high and does not parallel the conservation of the primary structure. A combination of structure prediction and probing experiments, however, results in a model consisting of structured domains of 100-200 nucleotides interspersed by long unpaired cytosine-rich regions. The latter may interact with the coat protein inside the virion. The structure of some functionally interesting regions of the 3' part of TYMV RNA is also discussed.

Haemoperfusion in Amanita phalloides poisoning.

Amanita phalloides is responsible for about 90 per cent of all fatal cases of mushroom intoxication. The amatoxins, the main toxic component of these fungi, are responsible for gastro-intestinal symptoms as well as hepatic and renal failure. Three brothers with Amanita phalloides poisoning were admitted with gastro-intestinal symptoms beginning 12 h after ingestion. Jaundice, hepatomegaly and neurological symptoms were not present, but liver enzymes were moderately increased. Alfa-amanitin was detected in sera of all patients. All patients underwent charcoal hemoperfusion and two of them had additional hemodialysis along with conservative therapy. Liver enzymes that showed a marked increase on the second day of therapy decreased to normal levels on the 28th day. All of our patients survived. This life saving role of early haemoperfusion in Amanita phalloides poisoning is emphasized.

[Plant poisoning cases in Turkey]. / Les intoxications d'origine végétale en Turquie.

In Turkey, the majority of the population live in rural areas where they use wild plants as food and medicine. The confusion of an edible plant with a poisonous one give rise to serious poisoning which may even result in death. The incidence of plant poisoning in Turkey is about 6% and especially high among children between ages of 2 and 11 living in rural areas. The number of species that cause poisoning is around twenty and Hyoscyamus niger (Solanaceae), Colchicum species (Liliaceae), Conium maculatum (Umbelliferae) and Prunus species (Rosaceae) are the most important. Mushroom poisoning is more frequent in spring and fall. The main reasons are their widespread usage as food and the inexperience of the gatherers in distinguishing the edibles from the poisonous. Amanita phalloides, A. verna, A. muscaria, A. pantherina are responsible for severe cases of poisoning.

Poisoning by toxic honey in Turkey.

One of the food intoxications encountered in Turkey is the case caused by toxic honey made by bees from Rhododendron species. R. luteum and R. ponticum are the two species which grow in the north regions of Turkey. Grayanotoxins, mainly Grayanotoxin I (Andromedotoxin) occurring only in Ericaceae plants, are the compounds responsible for poisoning. In this investigation, the diagnosis and treatment of 11 cases of poisoning admitted to Kartal Occupational Diseases Hospital between 1983 and 1988 are presented. The results of the light microscopic and chemical analysis of toxic honey samples are compared with those of the ordinary honey samples and the extract of Rhododendron leaves.