Does Lake Titicaca still control the Lake Poopó system water levels? An investigation using satellite altimetry and MODIS data (2000–2009)

Complementary analysis of satellite mission data (altimetry, Moderate Resolution Imaging Spectroradiometers (MODIS)) and climate fields over 2000–2009 was conducted to investigate the variability of the water cover surfaces and the geographical source of water inflowing into the Lake Poopó system. The results suggest that over the time span of 2000–2009 a great part of the variability of the Poopó system originates from geographic sources other than Lake Titicaca. Possible alternative causes include climate change inducing increased temperatures and greater evaporation rates along the Altiplano; increased glacier and snow melting over the Andes Cordillera; and a potential increased anthropogenic water use (such as irrigation, minery, etc.) throughout the path of the Desaguadero River (which connects lakes Titicaca and Poopó). This change in the hydrology of this region could lead to a collapse of water supplies and endanger the already fragile Poopó system as well as the regional socioeconomic system, which closely depends upon it.     

Systematic search for neutropenia should be part of the first screening in patients with poikiloderma

Poikiloderma occurs in a number of hereditary syndromes, the best known of which is Rothmund-Thomson syndrome (RTS). Differential diagnoses include Dyskeratosis Congenita (DC) with high genetic heterogeneity and Clericuzio-type Poikiloderma with Neutropenia (CPN) due to mutations in the C16orf57 gene. Mutations in the RECQL4 gene are only observed in two thirds of RTS patients. In this study, 10 patients referred for syndromic poikiloderma and negative for RECQL4 sequencing analysis were investigated for C16orf57 mutations. Two C16orf57 heterozygous nonsense mutations (p.W81X and p.Y89X) were identified in a 5-year-old female child presenting with generalized poikiloderma, dental dysplasia, gingivitis, nail dystrophy, palmoplantar keratoderma and pachyonychia of the great toenails. Previously undetected and silent neutropenia was evidenced after C16orf57 molecular analysis. Neutropenia was absent in the C16orf57-negative patients. This report confirms that neutrophil count should be performed in all patients with poikiloderma to target the C16orf57 gene sequencing analysis, prior to RECQL4 analysis.     

MicroRNAs in Genetic Disease: Rethinking the Dosage

To date, the general assumption was that most mutations interested protein-coding genes only. Thus, only few illustrations have mentioned here that mutations may occur in non-protein coding genes such as microRNAs (miRNAs). We thus report progress in delineating their contribution as phenotypic modulators, genetic switches and fine-tuners of gene expression. We reasoned that browsing their contribution to genetic disease may provide a framework for understanding the proper requirements to devise miRNA-based therapy strategies, in particular the relief of an appropriate dosage. Gain and loss of function of miRNA enforce the need to respectively antagonize or supply the miRNAs. We further categorized human disease according to the different ways in which the miRNA was altered arising either de novo, or inherited whether as a mendelian or as an epistatic trait, uncovering its role in epigenetics. We discuss how improving our knowledge on the contribution of miRNAs to genetic disease may be beneficial to devise appropriate gene therapy strategies.     

Hepcidin and Iron Deficiency in Women One Year after Sleeve Gastrectomy: A Prospective Cohort Study

Iron deficiency with or without anemia, needing continuous iron supplementation, is very common in obese patients, particularly those requiring bariatric surgery. The aim of this study was to address the impact of weight loss on the rescue of iron balance in patients who underwent sleeve gastrectomy (SG), a procedure that preserves the duodenum, the main site of iron absorption. The cohort included 88 obese women; sampling of blood and duodenal biopsies of 35 patients were performed before and one year after SG. An analysis of the 35 patients consisted in evaluating iron homeostasis including hepcidin, markers of erythroid iron deficiency (soluble transferrin receptor (sTfR) and erythrocyte protoporphyrin (PPIX)), expression of duodenal iron transporters (DMT1 and ferroportin) and inflammatory markers. After surgery, sTfR and PPIX were decreased. Serum hepcidin levels were increased despite the significant reduction in inflammation. DMT1 abundance was negatively correlated with higher level of serum hepcidin. Ferroportin abundance was not modified. This study shed a new light in effective iron recovery pathways after SG involving suppression of inflammation, improvement of iron absorption, iron supply and efficiency of erythropoiesis, and finally beneficial control of iron homeostasis by hepcidin. Thus, recommendations for iron supplementation of patients after SG should take into account these new parameters of iron status assessment.     

Protoflavonoids from ferns impair centrosomal integrity of tumor cells

Six protoflavonoids, including two new compounds, were isolated during a large scale screening of fern extracts for original interaction with mitosis. The new compounds isolated from PHEGOPTERIS decursive-pinnata and EQUISETUM fluviatile were 2',3'-dihydroprotogenkwanone (1) and 2',3'-dihydro-2'-hydroxyprotoapigenone (2). Known compounds were: protoapigenone, protogenkwanone, protoapigenin, and 4'- O- β-D-glucopyranosyl protoapigenin. They showed a cytotoxic activity against HeLa cells at a micromolar level. IC?? values were 2 μM for compound 1 > 10 μM for compound 2, and respectively 2.4, 0.6, > 10 μM for the known compounds. Their cytotoxic effects were associated with phenotypic changes never observed before and characterized by the loss of centrosomal γ-tubulin labelling in both mitotic and interphasic cells.     

Increased inferior frontal activation during word generation: A marker of genetic risk for schizophrenia but not bipolar disorder?

During verbal‐fluency tasks, impairments in performance and functional abnormalities in the inferior frontal cortex have been observed in both schizophrenia patients and their unaffected relatives. We sought to examine whether such functional abnormalities are a specific marker of genetic vulnerability to schizophrenia. We studied a sample of 132 subjects, comprising 39 patients with schizophrenia, 10 unaffected monozygotic (MZ) cotwins of schizophrenia probands, 28 patients with bipolar disorder, 7 unaffected MZ cotwins of bipolar disorder probands and 48 healthy controls. Blood oxygen level‐dependent response was measured using functional magnetic resonance imaging during the performance of an overt verbal‐fluency task with two levels of task difficulty, in a cytoarchitectonic region of interest encompassing Brodmann areas 44 and 45 bilaterally. Patients with schizophrenia and the unaffected MZ cotwins of schizophrenia probands showed increased activation in the inferior frontal cortex relative to healthy controls and bipolar patients. Increased engagement of the inferior frontal cortex during verbal‐fluency may thus be a marker of genetic vulnerability to schizophrenia. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.