Deletion of the mental retardation gene Gdi1 impairs associative memory and alters social behavior in mice

Non-specific mental retardation (NSMR) is a common human disorder characterized by mental handicap as the only clinical symptom. Among the recently identified MR genes is GDI1, which encodes alpha Gdi, one of the proteins controlling the activity of the small GTPases of the Rab family in vesicle fusion and intracellular trafficking. We report the cognitive and behavioral characterization of mice carrying a deletion of Gdi1. The Gdi1-deficient mice are fertile and anatomically normal. They appear normal also in many tasks to assess spatial and episodic memory and emotional behavior. Gdi1-deficient mice are impaired in tasks requiring formation of short-term temporal associations, suggesting a defect in short-term memory. In addition, they show lowered aggression and altered social behavior. In mice, as in humans, lack of Gdi1 spares most central nervous system functions and preferentially impairs only a few forebrain functions required to form temporal associations. The general similarity to human mental retardation is striking, and suggests that the Gdi1 mutants may provide insights into the human defect and into the molecular mechanisms important for development of cognitive functions.     

Cross-Sectional Associations between Mothers and Children’s Breakfast Routine—The Feel4Diabetes-Study

Positive influences of family members have been associated with a high probability of children’s daily breakfast consumption. Therefore, the aim of this study was to scrutinize the association of breakfast routines between mothers and their children. The baseline data of the Feel4Diabetes-study was obtained in 9760 children (49.05% boys)–mother pairs in six European countries. A parental self-reported questionnaire gauging the frequency of breakfast consumption and of breakfast´ foods and beverages consumption was used. Agreement in routines of mothers and their children’s breakfast consumption was analyzed in sex-specific crosstabs. The relationship of breakfast routine and food groups’ consumption between mothers and their children was assessed with analysis of covariance. The highest proportion of children who always consumed breakfast were those whose mothers always consumed it. Children consuming breakfast regularly had a higher intake of milk or unsweetened dairy products and all kind of cereal products (low fiber and whole-grain) than occasional breakfast consumers (p < 0.05). The strong similarity between mothers and children suggests a transfer of breakfast routine from mothers to their children, as a high proportion of children who usually consume breakfast were from mothers also consuming breakfast. All breakfast foods and beverages consumption frequencies were similar between children and their mothers.     

Is Erythrocyte Damage Prevented by Gardos Effect in Hemodialyzed Uremic Patients?

The purpose of this study was to determine the changes of calcium and potassium content in red blood cells (RBC) from uremic patients during a hemodialysis (HD) session. In 17 uremic patients on HD, the calcium and potassium content of RBC was determined in 3 blood samples collected at 0 min-HD (pre-HD), 45 min-HD, and 240 min-HD (end-HD) during a 4 h HD session. The calcium and potassium content of RBC also was determined in 20 normal subjects (controls). The mean values (+/-SD) of RBC calcium content in patients at 0 min-HD, 45 min-HD, and 240 min-HD were 1.95 +/- 0.34, 2.82 +/- 0.50, and 2. 05 +/- 0.4 microg/ml, respectively, and in controls 0.61 +/- 0.14 microg/ml. These values show that the RBC calcium in patients was generally significantly higher (p < 0.0001) in comparison to that of controls. The RBC calcium at 45 min-HD was significantly higher as compared to that at 0 min-HD and at 240 min-HD (p < 0.0001). The mean values (+/-SD) of RBCs' potassium in uremic patients at the previously mentioned measurements were 95.9 +/- 3.34, 92.5 +/- 4.32, and 93.85 +/- 3.89 mEq/L, respectively, and in controls 98.46 +/- 2. 30 mEq/L. These values show that RBC potassium of patients was generally significantly lower in comparison to controls (0 min-HD: p < 0.01, 45 min-HD and 240 min-HD: p < 0.001). Potassium decrease also was significantly lower at 240 min-HD (p < 0.01) and even lower at 45 min-HD (p < 0.001) compared to that at 0 min-HD. In conclusion, uremic patients during an HD session present a high calcium and a low potassium content of erythrocytes. These changes may prevent swelling of the cells (Gardos effect).     

Aggregation of childhood leukemia in geographic areas of Greece)

A total of 872 children aged up to 14 years, who were diagnosed withleukemia in Greece during the decade 1980-89, were allocated by place ofresidence to the 601 administrative districts of the country. Evaluation ofspatial clustering was done using the Potthoff-Whittinghill method, whichvalidly assesses heterogeneity of leukemia risk among districts with variableexpected numbers of cases. There was highly significant evidence for spatialclustering occurring particularly among children living in urban and, to alesser extent, semi-urban areas. The evidence was stronger for childrenyounger than 10 years old, applied also to children in different five-yearage groups, and persisted when cases of acute lymphoblastic leukemia wereanalyzed separately. These findings provide support to the hypothesis thatlocalized environmental exposures could contribute to the etiology ofchildhood leukemia, but they cannot distinguish between exposures of physicalor chemical nature, nor can they exclude socially conditioned patterns ofexposure to infectious agents.     

Immunogenicity and side‐effects of the inactivated hepatitis A vaccine in periodic fever,aphthous stomatitis,pharyngitis, and adenitis patients

The aim of this study was to compare the immunogenicity and side‐effects of hepatitis A virus (HAV) vaccination between periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) patients and healthy controls who have not been previously exposed to HAV. A prospective observational study was carried out of 28 PFAPA patients and 76 controls who received two doses of the vaccine. Immunogenicity was expressed as seroconversion and seroprotection rates; mean HAV‐immunoglobulin G concentration was measured at 0, 1, 7 and 18 months. Side‐effects were defined as incidence of adverse events and the effect of vaccination on PFAPA symptoms. All participants were seronegative and seroconverted at 1 month. One month after primary vaccination, 92.9% of PFAPA patients and 77.6% of the controls attained seroprotection, while the rates increased to 100% and 96.1%, respectively, 1 month after the second dose. Seroprotection rates remained adequate 1 year after completion of vaccination. In conclusion, two doses of the inactivated HAV vaccine are well‐tolerated and effective in children with PFAPA.