The assessment of positivity and negativity in social networks: the reliability and validity of the social relationships index

The Social Relationships Index (SRI) was designed to examine positivity and negativity in social relationships. Unique features of this scale include its brevity and the ability to examine relationship positivity and negativity at the level of the specific individual and social network. The SRI's psychometric properties were examined in three studies. The SRI demonstrated good psychometric properties, including test–retest reliability for the assessment of positivity and negativity, and of relationship classifications across social networks. Additionally, discriminant and convergent validity was established with existing social relationship and personality scales. Finally, the SRI showed some generalizability across different contexts. These studies suggest that the SRI is a reliable and valid alternative measure for use in health studies that require a shorter assessment of relationships. © 2009 Wiley Periodicals, Inc.     

Treatment Results of Nasopharyngeal Cancer a nationwide survey from Finland

The nationwide experience of treating nasopharyngeal cancer in Finland during the period 1980-1989 was reviewed. Of the 107 patients included in the present analysis, 13 were treated palliatively only, and three had metastatic disease at their first clinical presentation, whereas the rest (n = 91) were treated with radical radiotherapy, of whom, 8 patients received adjuvant chemotherapy after radiotherapy. The 5-year actuarial survival rates of these 91 patients was 52%, and by the UICC stage they were classified as follows: stage I 75% (n = 12), stage II 60% (n = 5), stage III 59% (n = 34), and stage IV 38% (n = 40). According to the Cox's stepwise proportional hazard model the most important factors influencing favourable survival were the total dose of radiotherapy expressed in terms of Biologically Effective Dose (BED) with a time factor, a small size of the primary tumour and a high performance status according to the WHO scale, whereas the most important factors influencing the local control analysis were the total dose of radiotherapy (expressed in BED) and the cervical lymph node status.     

Genetic and environmental influences on the tracking of body size from birth to early adulthood

OBJECTIVE: This study identified genetic and environmental influences on the tracking of body size from birth to 16 to 18.5 years of age. RESEARCH METHODS AND PROCEDURES: Longitudinal information was collected from a nationally representative sample of Finnish twin adolescents (birth cohorts 1975 to 1979) and their parents through questionnaires mailed when the twins were ages 16 and 18.5 years old. The sample included 702 monozygotic, 724 same-sex dizygotic, and 762 opposite-sex dizygotic sets of twins. The measures used were length, weight, ponderal index (kilograms per cubic meters), and gestational age at birth, and height, weight, and body mass index (kilograms per square meters) at 16 to 18.5 years of age. The changes in genetic and environmental influences on body size from birth to early adulthood were analyzed by quantitative genetic modeling. RESULTS: The twins who had a higher weight or ponderal index at birth were taller and heavier in early adulthood, whereas those who were longer at birth were taller, but not heavier, later in life. Adult height was affected more by the birth size than body mass index. In the genetic modeling analyses, the genetic factors accounting for the variation of body size became more apparent with age, and both genetic and environmental influences on stature had a sizable carry-over effect from birth to late adolescence, whereas for relative weight, the influences were more age-specific. DISCUSSION: The genetic and environmental architecture of body size changes from birth to adulthood. Even in monozygotic twins who share their genetic background, the initially larger twin tended to remain larger, demonstrating the long-lasting effects of fetal environment on final body size.     

BDNF regulates the expression of fragile X mental retardation protein mRNA in the hippocampus

Both fragile X mental retardation protein (FMRP) and brain-derived neurotrophic factor (BDNF) are implicated in the maturation of neurons and in the higher cognitive functions. We have investigated whether FMRP and BDNF are reciprocally regulated in neurons. Exposure of cultured hippocampal neurons to BDNF, but not to NT-3, reduced FMR1 mRNA levels to 84.8% of control at 4 h and the levels were back to baseline by 24 h or 4 days. Furthermore, expression of FMR1 mRNA was reduced (82.4% of control) in vivo in the hippocampus of transgenic mice overexpressing TrkB receptors, and a small but significant (5.1%) decrease was also detected in FMRP protein levels. In contrast, the expression patterns of BDNF and TrkB mRNAs were not altered in FMRP-deficient mice compared to wild-type mice. Our data provide evidence that BDNF via TrkB signaling decreases FMRP expression and suggest a role for FMRP in BDNF-induced synaptic plasticity.