The role of peer networks in adolescent pornography use and sexting in Croatia

ABSTRACT

Although communication about sexuality is a significant pathway through which peers influence adolescent sexual development, little research has examined the role of peer networks in the use of sexualized media. We applied a social network approach to assess the role of close peers in adolescent pornography use and sexting in a sample of Croatian high school students. Sexual conversation networks’ characteristics did not correlate with pornography use. In contrast, sexting was associated with the proportion of same gender peers, the proportion of older peers and the proportion of sexually experienced peers in the network – pointing to the role of peer influence. Participants’ gender did not moderate these associations. Specific mechanisms underlying the observed associations and the role of peer selection remain important tasks for future research.     

Autologous Blood Stem Cell Transplantation in Hematological Malignancies

Autologous blood stem cell transplants (ABSCT) are increasingly used for the treatment of haematological malignancies. The use of hemopoietic growth factors, in conjunction with stem cell mobilization by chemotherapeutic agents, has permitted successful harvests requir ing only a few leukaphereses; cells mobilized in this manner contain a relatively large number of committed precursors of all lineages, as well as early progenitor cells capable of main taining long-term haemopoiesis. Haematological recovery after ABSCT is rapid, thereby sig nificantly shortening the period of post-chemotherapy neutropenia and thrombocytopenia. Furthermore, blood-derived grafts may contain fewer malignant cells than the bone marrow cells. The preliminary results have been so encouraging that it is envisaged that in myeloma, Hodgkin's disease and non-Hodgkin lymphomas, ABSCT may eventually replace autologous marrow transplantation.     

Cancer by negative heterosis: breast and ovarian cancer excess in hybrids of inbred ethnic groups

Breast and ovarian cancer rates in Pakistan are significantly higher than in neighboring countries. The cancer rate discrepancies cannot be explained with discrepancies of their risk factors. We propose that observed cancer excess in Pakistan is due to cancer development by negative heterosis. Heterosis occurs when a hybrid has a phenotypic characteristic significantly different from that in either parent (hybrid vigor). At a molecular level, heterosis occurs in a heterozygote when one of the two alleles is inactivated. Gene inactivation occurs by methylation of cytosine in a promoter region of a gene. Initiation of allele inactivation is linked to the factors like stress, gender, diet, or another gene. In heterozygote, inactivation of one of the two tumor-suppressor alleles leads to monoallelic expression. This increases cancer risk in the same way the risk is increased in individual who inherit a single mutated tumor-suppressor gene (hereditary cancer syndrome). In both, cancer by heterosis and inherited cancer syndrome, cancer develops after inactivation of a second allele (second hit hypothesis). In a population, conditions that favor development of cancer by heterosis are those that favor mating of a large number of different homozygotes because they produce a large number of different heterozygotes. Among a large number of heterozygotes, there is an increased chance that some of hybrids will develop cancer by heterosis. In Pakistan, conditions were favorable for cancer development by heterosis because country has a high number of different ethnic groups and brotherhoods all of which have a higher rate of homozygosity due to a high frequency of consanguineous marriages, and marriages between members of different groups occurred because of intense population mixing. Result was birth of a large number of inter-ethnic/brotherhood hybrids (heterozygotes), some of which have developed cancer by heterosis.     

Ageing is associated with a decrease in the number of sarcolemmal ATP-sensitive K+ channels in a gender-dependent manner

The opening of sarcolemmal K(ATP) channels is considered to be an important endogenous cardioprotective mechanism. On the other hand, age-dependent changes in the myocardial susceptibility to ischemia and hypoxia have been observed in different species, including humans. Here, we have hypothesized that aging might be associated with the changes in sarcolemmal K(ATP) channels. Therefore, the main objective of the present study was to establish whether aging changes expression of cardiac sarcolemmal ATP-sensitive K+ (K(ATP)) channels. RT-PCR using primers specific for K(ATP) channel subunits, Kir6.2, Kir6.1 and SUR2A subunits was performed using total RNA from guinea-pig ventricular tissue. Whole cell electrophysiology was done on isolated guinea-pig ventricular cardiomyocytes. Western blotting using anti-Kir6.2 and anti-SUR2A antibodies was performed on cardiac membrane fraction. Tissue and cells were harvested from young and old, male and female guinea-pigs. RT-PCR analysis did not reveal significant age-related changes in levels of Kir6.1 or Kir6.2 mRNAs. However, levels of SUR2A were significantly lower in old than in young females. Such age-differences were not observed with cardiac tissue from male animals. In both old and young males, pinacidil (100 microM) induced outward currents. The difference between current density of pinacidil-sensitive component in females, but not males, was statistically significant. Western blotting analysis revealed higher levels of Kir6.2 and SUR2A proteins in cardiac membrane fraction from young than old females. The present study demonstrates that in females, but not males, aging is associated with decrease in number of cardiac K(ATP) channels which is due to decrease in levels of the SUR2A subunit.     

Point-of-care measured serum cholinesterase activity predicts patient outcome following severe burns

Risk stratification is of utmost importance in burn therapy. However, suitable bedside biomarkers to evaluate the emerging inflammatory response following burn injuries are missing. Serum cholinesterase (butyrylcholinesterase, BChE) has been shown to be a clinically relevant biomarker in acute inflammatory diseases including burns.In this observational cohort study BChE activity was measured by using point-of-care testing (POCT), a novel method in acute burn care. POCT measurements were performed at emergency room admission (ERA) of 35 patients and repeated 12, 24 and 48 h later. All patients or their legal designees gave informed consent.Patients with burn injuries showed sustained BChE activity reduction following hospital admission. BChE activity correlated negatively with burn injury severity, organ failure severity and intensive care unit resource requirements. BChE activity measured at ERA and 12 h later identified survivors and predicted 28-day patient outcome with noninferior efficacy compared to the abbreviated burn severity index (ABSI) scoring. Finally, POCT-measured BChE activity might complement ABSI scoring and possibly improve early risk stratification in acute burn care therapy.     

Human V5/MT+: comparison of functional and cytoarchitectonic data

To date, the delineation of the human visual “motion area” still relies on functional paradigms originally devised to identify monkey area MT. Using fMRI, we have identified putative human area V5/MT+ in normals by modelling the BOLD responses to alternating radially moving and stationary dot patterns. Functional activations were compared with cytoarchitectonic probability maps of its putative correlate area hOc5, which was calculated based upon data from histological sections of ten human post-mortem brains. Bilateral visual cortex activations were seen in the single subject dynamic versus stationary contrasts and in the group random-effects analysis. Comparison of group data with area hOc5 revealed that 19.0%/39.5% of the right/left functional activation was assigned to the right/left hOc5. Conversely, 83.2%/53.5% of the right/left hOc5 was functionally activated. Comparison of functional probability maps (fPM) with area hOc5 showed that 28.6%/18.1% of the fPM was assigned to hOc5. In turn, 84.9%/41.5% of the area hOc5 was covered by the respective fPM. Thus, random-effects data and fPMs yielded similar results. The present study shows for the first time the correspondence between the functionally defined human V5/MT+ and the post-mortem cytoarchitectonic area hOc5.     

Risk factors for nipple involvement in breast cancer patients

Introduction: A clinically normal‐appearing nipple in patients with breast cancer may contain unsuspected neoplastic cells. Preservation of a nipple containing occult malignancy could potentially increase local recurrence rates and affect disease‐free survival. Consequently, patients considered for breast conservation operations with nipple preservation must be carefully selected. Methods: Information available on 382 patients diagnosed and treated with breast cancer at the Clinical Center Nis from 2000 to 2003 were retrospectively reviewed. Multivariate hazard analyses was used to assess the association between potential risk factors of cancerous nipple involvement. Results: The frequency of nipple involvement was 12.04%. Nearly half of the patients had disease stage III and IV. Most patients, 29 (63.04%), had a tumor to nipple distance of less then 2 cm. Twenty‐five patients (54.34%) had more then four positive axillary nodes. A central/overlap tumor location was present in 28 (60.87%) patients. Cox multivariate analysis of prognostic factors showed that Stage III (RH 4.79 (1.50–14.68, 1.50–14.72); P= 0.008), central/overlap tumor location (RH 3.28 (0.90–11.20); P= 0.078) and nuclear grade III or greater (RH 2.26 (0.79 to 6.65); P= 0.065) had a statistically significant effect on malign nipple involvement. Conclusions: The multivariable model used in this study showed a significant association between stage, centrally located tumors and nuclear grade III or greater in predicting the risk of cancerous nipple involvement. Preoperative magnetic resonance imaging or computed tomography scan examinations are recommended for treatment planning of breast cancer, in particular nipple preserving surgery in patients with central/overlap tumor localization and with a tumor to nipple distance of less than 2 cm.     

Mutation analysis of NANOS3 in 80 Chinese and 88 Caucasian women with premature ovarian failure

NANOS3 encodes an RNA-binding protein and has a conserved function in germ cell development. Our objective was to investigate whether mutations in NANOS3 were present in Chinese and Caucasian women with premature ovarian failure. A known synonymous single-nucleotide polymorphism (rs 2016163) in exon 1 was identified through sequencing 80 Chinese and 88 Caucasian women with premature ovarian failure. No additional single-nucleotide polymorphisms or mutations were found in exons encoding for NANOS3. Our findings suggest that mutations in NANOS3 exons are rare in both Chinese and Caucasian women with premature ovarian failure.