Tracking the Phylogeny of Seagrasses: Inferred from 18S rRNA Gene and Ancestral State Reconstruction of Morphological Data

Taxonomic challenges of seagrasses were met by using 18S ribosomal subunit of ribosomal deoxyribonucleic acid (18S rDNA) sequence data of 14 seagrass species from India and two temperate species from Germany. The phylogenetic trees presented are based on the 18S rDNA sequence analysis of 41 nucleotide sequences including sequences obtained in the present study as well as previously published sequences of freshwater and saltmarsh plants, and seagrasses for identifying the evolutionary lineage. The 18S rDNA data indicates independent origin of temperate and tropical seagrasses with the genus Halophila as the intermediate group for both the regions. Based on the complex morphological structures the Halophila group represents the basal form among seagrasses whereas Enhalus is considered to be the most recently originated seagrass species. In that context, the marine Hydrocharitaceae group of Enhalus, Thalassia and Halophila has been proposed to be separated into two groups such as Enhalus/Thalassia and Halophila subfamilies. Hence, the present systematic studies warrant a revised taxonomy for seagrasses, which better reflects the phylogenetic results obtained from molecular and conventional data.     

Empfehlungen zu Ernährung und Bewegung von Kleinkindern

Monatsschrift Kinderheilkunde -     

The pathology of ductal-type pancreatic carcinomas and pancreatic intraepithelial neoplasia: Insights for clinicians

The phenotypic classification of pancreatic neoplasms is based on their cellular lineage. Thus, tumors with a ductal, acinar, and endocrine phenotype can be distinguished. Most pancreatic neoplasms show a ductal phenotype and can be classified as ductal adenocarcinomas. Less common tumors with a ductal phenotype are the variants of ductal adenocarcinoma, intraductal papillary mucinous neoplasm (including colloid carcinoma), mucinous cystic neoplasm, medullary carcinoma, and other rare tumors. Ductal adenocarcinomas most likely develop from ductal proliferative lesions arising in the pancreatic duct system. A recently adopted classification system for these lesions distinguishes between three grades of pancreatic intraepithelial neoplasia (PanIN). Molecular studies have revealed that PanIN-2 and PanIN-3 lesions represent a distinct step toward invasive carcinoma.     

Management of the short bowel syndrome after extensive small bowel resection

Short bowel syndrome (SBS) is a global malabsorption syndrome that results from extensive intestinal resections. It used to be a typical complication of repetitive bowel resections in patients with Crohn's disease. However, due to improved medical and surgical therapies for these patients it currently occurs more frequently as a consequence of vascular disorders in adults (intestinal infarction) and congenital aberrations in children, respectively. Adequate therapy depends on the degree of (small) bowel losses and on resulting functional disturbances. Moreover, it must be adjusted to the postoperative adaptation process, which consists of three phases: The immediate acute phase lasts less than 4 weeks and serves to stabilise the patient. The subsequent year should be used to induce maximal adaptation by gradually increasing nutrient exposure. When maximal stimulation of nutrient absorption has been achieved, permanent maintenance nutrition treatment should be defined individually, dependent on extent and quality of nutritive deficits. In patients with Crohn's disease, optimal treatment of the underlying disease is of pivotal importance in order to avoid a further reduction of absorptive capacity or other complications. Current investigations aim at improving the adaptation process by administration of specific diets and growth hormones. With these, it appears possible to treat even some patients with very short bowel, i.e. less than 50 cm of small intestine left, with oral nutrition, only. Still, a considerable proportion of patients will need long-term parenteral nutrition. If young patients experience intolerable complications of parenteral nutrition, intestinal transplantation may be considered as a high risk therapy of last choice.     

Local injection of stem cell factor (SCF) improves myocardial homing of systemically delivered c-kit + bone marrow-derived stem cells

AIMS: Recent studies have shown that stem cell therapy may alleviate the detrimental effects of myocardial infarction. Yet, most of these reports observed only modest effects on cardiac function, suggesting that there still is need for improvement before widespread clinical use. One potential approach would be to increase migration of stem cells to the heart. We therefore tested whether local administration of stem cell factor (SCF) improves myocardial homing of intravenously infused lin-/c-kit+ stem cells after myocardial infarction. METHODS AND RESULTS: Myocardial infarction was induced in mice via ligation of the left anterior descending artery and 2.5 microg of SCF were injected into the peri-infarct zone. Sham-operated mice and animals with intramyocardial injection of phosphate-buffered saline (PBS) served as controls. Twenty-four hours after myocardial infarction, lin-/c-kit+ stem cells were separated from murine bone marrow by magnetic cell sorting, labelled with the green fluorescent cell tracker CFDA or 111 Indium, and subsequently 750 000 labelled cells were systemically infused via the tail vein. Another 24 or 72 h later, respectively (i.e. 48 and 96 h after myocardial infarction), hearts were removed and analysed for myocardial homing of stem cells. Green fluorescent stem cells were exclusively detected in the peri-infarct zone of animals having prior SCF treatment. Radioactive measurements revealed that an intramyocardial SCF injection significantly amplified myocardial homing of lin-/c-kit+ stem cells compared to animals with PBS injections (3.58 +/- 0.53 vs. 2.28 +/- 0.23 cpm/mg/10(6)cpm, +60%, P < 0.05) and sham-operated mice without myocardial infarction (3.58 +/- 0.53 vs. 1.95 +/- 0.22 cpm/mg/10(6)cpm, +85%, P < 0.01). Similar results were obtained 72 h after stem cell injection. CONCLUSION: We demonstrate that intramyocardial administration of SCF sustainably directs more lin-/c-kit+ stem cells to the heart. Future studies will have to show whether higher levels of myocardial SCF (i.e. by virus-mediated gene transfer) can further improve homing of systemically delivered c-kit+ stem cells and thus favourably influence cardiac remodelling following myocardial infarction.     

Emergence of a New Norovirus GII.4 Variant and Changes in the Historical Biennial Pattern of Norovirus Outbreak Activity in Alberta,Canada, from 2008 to 2013

The public health impact of the emergence of new norovirus (NoV) strains is uncertain. A biennial pattern of alternating quiescent and epidemic levels of NoV outbreak activity associated with the emergence of new GII.4 variants was observed in Alberta, Canada, between July 2000 and June 2008. In this study, NoV genogroup I (GI) and GII strains isolated from 710 outbreak specimens in Alberta between July 2008 and January 2013 were characterized to update historical data. The seasonality and annual variation in NoV outbreak burden were analyzed over a 10-year period (July 2002 to June 2012). We found that GII.4-2006b had persisted as the predominant variant over three observation periods (July 2006 to June 2009) during which the biennial NoV outbreak pattern continued. The emergence of GII.4-2010 (winter 2009) was not associated with increased outbreak activity, and outbreak activity between July 2009 and June 2012 when GII.4-2010 predominated (67.5 to 97.7%) did not follow a biennial pattern. GII.4-2012 first emerged in Alberta in September 2011 and became predominant in observation period July 2012 to June 2013. NoV GI, relatively rare in past years, had a higher activity level (37.3%) as represented by GI.6 and GI.7 in the winter of 2012 to 2013. A higher proportion of GI outbreaks occurred in non-health care facility settings compared to GII. Our study suggests that factors other than new variants emergence contribute to the levels of NoV outbreak activity in Alberta.     

Children's risk and resilience following a natural disaster: Genetic vulnerability,posttraumatic stress,and depression

Objective

We examined children’s risk and resilience following a natural disaster, evaluating the role of stress, social support, and two genetic markers: the short allele of the serotonin transporter gene (5-HTTLPR), and the met allele of the Brain-Derived Neurotrophic Factor (BDNF).Under high levels of hurricane exposure or hurricane-related stressors, we expected children displaying the markers would report greater symptoms of posttraumatic stress disorder (PTSD) and depression than children without these markers. Social support was explored as an additional moderating variable.

Method

Eight months after Hurricane Ike, 116 children (M age=8.85 years, SD=.89; 54% girls) residing in Galveston, Texas, provided saliva samples and completed measures of hurricane exposure and stress, and symptoms of PTSD and depression; 80 also completed a social support measure.

Results

For BDNF, analyses revealed several Gene by Environment interactions; greater stress was related to more symptoms of PTSD and depression, and this effect was stronger for children with the met allele. No findings emerged for 5-HTTLPR. Stressors and social support also were associated with children’s PTSD and depressive symptoms.

Limitations

Findings should be tempered by the relatively small sample, especially for analysis that included social support.

Conclusions

The met allele (BDNF) may play a role in children’s disaster reactions. Further research should consider the complex interplay between genes, stressors, support, and psychological outcomes over time.     

Age-related changes in processing positive and negative feedback: Is there a positivity effect for older adults?

Older people sometimes show a bias toward the processing of positive information. In this study, we used an event-related potential approach to examine whether such a positivity bias is also present during feedback processing in older adults. Our results suggest that a fast initial monitoring process, as reflected in the feedback-related negativity (FRN), is sensitive to the expectancy of events irrespective of their valence for older (aged 70–77 years) as well as younger (aged 20–27 years) adults. In contrast, in a later evaluation process, associated with memory updating and indexed by the P300, both age groups preferably processed unexpected positive feedback. However, younger adults additionally differentiated between unexpected negative and expected feedback while older adults did not, probably due to a lower working memory capacity.     

PD1 expression and correlation with its ligands in oral cancer specimens and peripheral blood

ObjectivesThis study analyzed the expression of the PD1 receptor in tumor tissue and peripheral blood of oral squamous cell carcinoma (OSCC) patients, and correlated it with the PD1 ligands PD-L1 and PD-L2. The currently low response rates of checkpoint inhibitor treatment in OSCC could be increased by a better understanding of immune checkpoint biology. Despite evidence in the literature for upregulation of PD1 checkpoint ligands in OSCC tissue, there has been no correlation analysis of the PD1 receptor with its ligands in tissue specimens and peripheral blood of OSCC patients.Materials and methodsAn RT-qPCR analysis of PD1 mRNA expression was performed in oral cancer specimens, healthy mucosa, and corresponding blood samples. A cut-off point (COP) was determined and a chi-square (χ²) test was carried out. PD1 expression was correlated with previously reported PD-L1 and PD-L2 expression values using the Spearman test.ResultsTissue and blood specimens of 48 OSCC patients and 26 healthy individuals were analyzed. PD1 expression in OSCC specimens was significantly increased (p = 0.006) compared with healthy oral mucosa. PD1 overexpression in tissue samples showed a significant association with the presence of malignancy (p = 0.006). PD1 expression in tissue samples showed a significant positive correlation (p < 0.001) with the ligands PD-L1 and PD-L2. In contrast, there was no correlation between PD1 and its ligands in blood samples. However, there was a significant positive correlation (p < 0.001) between the ligands PD-L1 and PD-L2, both in tissue and blood samples.ConclusionsIncreased PD1 expression might be a manifestation of T-cell exhaustion in OSCC specimens, leading to immune tolerance. PD-L1/PD-L2-PD1 interaction may be a major mediator of local immunosuppression in OSCC, requiring advanced multimodal treatment protocols.