Cytogenetic and molecular genetic analysis of tumorigenic human bronchial epithelial cells induced by radon alpha particles

To establish a cell culture model for lung carcinogenesis, independent populations of the human papillomavirus 18-immortalized human bronchial epithelial cell line BEP2D were treated with high linear energy transfer radon-simulated alpha-particles, expanded and xenotransplanted into Nu/Nu mice. Six independent cell lines were established from tumors that developed from three separate radiation treatments as follows: treatment (Tx) 1 (30 cGy--two doses), H2BT, Tx 2 (30 cGy-- single dose), R30T1L, R30T2 and R30T3L, Tx 3 (30 cGy--single dose), H1ATN and H1ATBA1. Cytogenetic analysis revealed common changes in all tumor lines: loss of the Y chromosome (ch), one of three copies of ch8, one of three copies of ch14, and one of two copies of ch4p16-pter and ch11p15-pter. Analysis of polymerase chain reaction-amplified short tandem repeats of informative loci confirmed the loss of chY in all lines and loss of heterozygosity (LOH) at eight loci spanning the length of ch8 in all lines from Tx's 1 and 2. Our data support previous studies indicating the presence of tumor suppressor genes on ch8. LOH also was confirmed on ch14 at locus D14S306 in all cell lines from Tx 2 and in one of two lines from Tx 3. This region, 14q12-q13, may contain changes in one of the five known somatostatin receptor genes (SSTR1). No LOH was detected at any of the informative loci tested for on ch4 or ch11.      

After teen suicide: issues for pediatricians who are asked to consult to schools

Every suicide is a unique tragedy. This article has attempted to provide a framework for understanding suicide as it impacts on the school community. Given this background, we have listed 10 frequent dilemmas faced by pediatricians (and others) who consult to schools. The central themes of the approach offered are to avoid inadvertently glorifying suicide, target high-risk groups for interventions, and consider suicide prevention as part of the broad, ongoing task of providing a caring environment for adolescents in which the collaboration of the school community is essential.     

Bradyarrhythmias and Laparoscopy: A Prospective Study of Heart Rate Changes with Laparoscopy

Cardiac arrhythmias are a common complication of laparoscopy. Brady-arrhythmias (including asystole) may be life-threatening. The recent introduction of new shorter-acting muscle relaxants (atracurium and vecuronium), with their lack of vagolytic activity, may exacerbate this situation. At the Royal Women's Hospital there have been several episodes of severe bradyarrhythmias and/or asystole associated with these relaxants. This study evaluated heart rate changes in 49 women during laparoscopy: 47% of patients had arrhythmias, 30% of these being bradyarrhythmias. Nearly all the episodes occurred during carbon dioxide insufflation or with traction on pelvic structures. The life-threatening nature of this phenomenon should be understood by all anaesthetists and gynaecologists engaged in laparoscopic procedures.     

Fluid and electrolyte balance in the postoperative period

Authors investigated the concentration changes of arginine vasopressin (AVP) and of atrial natriuretic peptide (ANP) in plasma. The renal characteristics of water- and sodium metabolism in the first 24 hours of the postoperative period in 11 children operated with acute appendicitis have been studied. Crystalloid infusion was applied in 60 ml/kg/24 h dose, in 5 cases however, 1 g/kg albumin vas also administered during the operation. In children getting crystalloid infusion (group "A") the initial AVP value was 29.9 +/- 8.8 pg/ml, which further increased to 58.2 +/- 15.2 pg/ml (p 0.05) by the 6. postoperative hour and even in the 24. hour it remained above the physiological value (19.9 +/- 5.3 pg/ml). During the observation time significant Na- and water retention developed. The albumin administration (group "B") stopped the further increase of AVP values, the Na-household remained in equilibrium and the water retention developed only in smaller degree. The ANP plasma concentration of both groups was in the normal range and did not change during observation time. Our data show that for the postoperative water retention first of all the increased AVP activity is responsible. The more intensive AVP secretion may be induced by the relative intravascular hypovolemia since by enhancing the plasma volume the further increase of postoperative hormone activity could be prevented.     

Predicting the response to recombinant human growth hormone in Turner syndrome: KIGS models

A mathematical model for predicting the growth response in patients with Turner syndrome who received growth hormone (GH) therapy was developed by analysing data from KIGS, the Pharmacia & Upjohn International Growth Database. A Model for year 1 of GH therapy explained 46% of the variability of the growth response, with GH dose being the most important of the predictors of height velocity. In years 2-4 of therapy, height velocity during the previous year was the most important predictor, suggesting that an individual's initial response to GH may determine the height outcome of treatment. Additional treatment with oxandrolone. The predictions in all 4 years were highly accurate, as indicated by the low error SDs. However, relatively low predictive power ( R ) during years 2-4 of treatment suggests the models are missing other parameters that would explain more of the variability of the growth response. These growth prediction models could help clinicians to design individualized treatment regimens, provide realistic expectations of therapy outcomes, and adjust treatment on the basis of detected differences between observed and predicted height velocities.