Schizotypy: a vulnerability factor for traumatic intrusions

Intrusive mental experiences occur within posttraumatic stress disorder (PTSD) and some psychotic disorders. Similarities in the phenomenology and content in the intrusions of both disorders have been noted. Currently there is little understanding of any common etiology in terms of information-processing styles. This study investigated predictors of analogue posttraumatic intrusive cognitions within a nonclinical sample, including schizotypy, dissociation, and trauma history. Forty-two participants watched a trauma video and recorded trauma-related intrusions occurring for 1 week. More reported intrusive experiences were associated with high positive symptom schizotypy. Our findings are discussed in relation to the possible role of trauma-related intrusions within psychotic disorders.     

Risk of malignancy in diagnosed coeliac disease: a 24-year prospective, population-based, cohort study

BACKGROUND: There is recent evidence from studies of hospitalized and of undiagnosed patients that the risk of lymphoma for people with coeliac disease may be lower than previously thought. In addition, there have been no precise estimates of small bowel lymphoma risk due to a lack of population data. AIM: To examine these and other malignant risks in a cohort of patients more typical of those seen in routine clinical practice. METHODS: A prospective cohort study of incident malignancy rates in patients with coeliac disease in southern Derbyshire compared with general population figures. RESULTS: During 5684 person years of follow-up 31 malignancies (excluding non-melanoma skin cancer) occurred in comparison with 30.30 expected [standardized incidence ratio (SIR) 1.02 (0.69-1.45)]. There were four non-Hodgkin's lymphomas (0.69 expected) SIR 5.81 (1.58-14.86), of which one originated in small bowel (0.02 expected) SIR 40.51 (1.03-225.68). GI malignancy occurred in nine (5.71 expected) SIR 1.58 (0.72-2.99), and breast cancer in three (5.08 expected) SIR 0.59 (0.12-1.73). CONCLUSIONS: There is no increase in the risk of incident malignancy in this population and the risk of non-Hodgkin's lymphoma in general or of the small bowel is lower than previously found from UK coeliac cohorts.     

Naltrexone for heroin dependence treatment in St. Petersburg, Russia

Naltrexone may be more effective for treating opioid (heroin) dependence in Russia than in the U.S. because patients are mostly young and living with their parents, who can control medication compliance. In this pilot study we randomized 52 consenting patients who completed detoxification in St. Petersburg to a double blind, 6-month course of biweekly drug counseling and naltrexone, or counseling and placebo naltrexone. Significant differences in retention and relapse favoring naltrexone were seen beginning at 1 month and continuing throughout the study. At the end of 6 months, 12 of the 27 naltrexone patients (44.4%) remained in treatment and had not relapsed as compared to 4 of 25 placebo patients (16%; p<0.05). Since heroin dependence is the main way HIV is being spread in Russia, naltrexone is likely to improve treatment outcome and help reduce the spread of HIV if it can be made more widely available.     

Determination and analysis of single nucleotide polymorphisms and haplotype structure of the human carboxylesterase 2 gene

Carboxylesterases are members of the serine esterase super family important in the metabolism of a wide variety of substrates, including xenobiotics and prodrugs. There are two known carboxylesterases expressed in human liver, small intestine and other tissues, carboxylesterase 1 (CES1) and carboxylesterase 2 (CES2). The aim of this study was to identify polymorphisms in the CES2 gene and determine whether these polymorphisms affect expression levels of CES2 or rate of metabolism of irinotecan (7-ethyl-10-[4-(1-piperidino)-1-piperidino] carbonyloxy-camptothecin). Microsome samples prepared from liver tissues of 78 normal individuals were used to determine the rate of hydrolysis of irinotecan and procaine (an anaesthetic hydrolysed by CES2 but not CES1). The rate of hydrolysis of irinotecan is highly variable among individuals, ranging from 2.7-138 pmol/mg protein/h (mean +/- SD 26.0 +/- 22.9). Fifteen single nucleotide polymorphisms (SNPs) were identified, one is in an exon, 9 are in introns, three are in the 3'-untranslated region (UTR), and two are in the 5'-flanking region. Eight of the 15 SNP loci have rare allele frequencies greater than 5%, of which three were greater than 20%. Genotyping of samples from the SNP Consortium demonstrated different distributions among African-Americans, Asian-Americans and European-Americans. We also analysed the haplotype structure and estimated linkage disequilibrium (LD). A SNP located in the 5'-UTR (5'-UTR-363) was found in LD with loci in intron 1 (Intron1 + 947, Intron1 + 1361, Intron1 + 1643). Haplotypes with homozygous rare alleles on these loci exhibit lower mRNA levels as determined by real time polymerase chain reaction (P < 0.01) and the incorporation of rare alleles in haplotypes correlate with reduced mRNA (P = 0.03). The 5'-UTR-363 SNP is located in one of the three promoters of CES2. However, we did not observe significant differences in CES2 activities (irinotecan and procaine hydrolysis) among individuals with different haplotypes.     

The anti-thyroid drug methimazole induces neovascularization in the neonatal rat analogous to ROP

PURPOSE: To determine the effect of methimazole (MMI), an anti-thyroid drug known to reduce serum l-thyroxine (T4), and insulin-like growth factor (IGF)-1 concentrations, on retinal vascular development in neonatal rats. METHODS: Sprague-Dawley rats (n=175) were raised in expanded litters of 25 in room air and were exposed to MMI from birth (given as a 0.1% solution to nursing mothers for either 4 or 10 days). Experiments ended on day 4 (n=25) or 10 (n=50) of life. A third group was exposed to MMI for the initial 4 days of life and then allowed to recover for the next 6 days (n=50). Fifty control rats were analyzed on day 4 (n=25) or 10 (n=25) of life. Left eyes were fixed, and retinas were dissected and stained with adenosine diphosphatase (ADPase). Retinas were graded for presence and severity of neovascularization (NV) in a masked manner, and retinal vascular areas were quantified. In a subsequent study, serum IGF-1 and T4 levels were measured by radioimmunoassay in an additional 200 rats exposed to treatments identical to those described. RESULTS: Retinal NV occurred in 31% of rats exposed to 10 days of MMI and 4% (P=0.02) of rats exposed to 4 days of MMI, followed by 6 days of recovery. None of the rats exposed to 4 days of MMI alone and none of the control animals was graded positive for NV. Retinal vascular areas were significantly reduced in rats exposed to 4 days of MMI compared with 4-day control animals (36% +/- 6% vs. 50% +/- 6%, P=0.0001). Serum IGF-1 levels were markedly reduced in 4-day MMI rats compared with age-matched control animals (42 ng/mL vs. 133 ng/mL, P=0.0001) and in 10-day MMI rats compared with 10-day control animals (133 ng/mL vs. 206.5 ng/mL, P=0.005). Serum T4 levels were similarly suppressed in the MMI-exposed litters compared with control animals at day 10 (P=0.008). In contrast, rats exposed to 4 days of MMI followed by 6 days of recovery had normal serum IGF-1 and T4 levels by day 10. CONCLUSIONS: The anti-thyroid drug, MMI, induces NV in neonatal rats. This may be mediated by the initial suppression of serum IGF-1. Nevertheless, the lower incidence of NV when serum IGF-1 levels are initially suppressed followed by complete recovery, is contrary to a purely permissive role for serum IGF-1, as reported previously. The relationship between the temporal course of serum IGF-1 and NV in immature retinas needs further investigation.     

Methods to assess intended effects of drug treatment in observational studies are reviewed

BACKGROUND AND OBJECTIVE: To review methods that seek to adjust for confounding in observational studies when assessing intended drug effects. METHODS: We reviewed the statistical, economical and medical literature on the development, comparison and use of methods adjusting for confounding. RESULTS: In addition to standard statistical techniques of (logistic) regression and Cox proportional hazards regression, alternative methods have been proposed to adjust for confounding in observational studies. A first group of methods focus on the main problem of nonrandomization by balancing treatment groups on observed covariates: selection, matching, stratification, multivariate confounder score, and propensity score methods, of which the latter can be combined with stratification or various matching methods. Another group of methods look for variables to be used like randomization in order to adjust also for unobserved covariates: instrumental variable methods, two-stage least squares, and grouped-treatment approach. Identifying these variables is difficult, however, and assumptions are strong. Sensitivity analyses are useful tools in assessing the robustness and plausibility of the estimated treatment effects to variations in assumptions about unmeasured confounders. CONCLUSION: In most studies regression-like techniques are routinely used for adjustment for confounding, although alternative methods are available. More complete empirical evaluations comparing these methods in different situations are needed.     

Immune systems, geographic information systems (GIS), environment and health impacts

Exposure to dioxins, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) has been related to alterations in cellular and humoral immune responses in both adaptive and innate immune systems of most animal species. These compounds share a common signaling mechanism to exert their effects on cells of the immune system, which includes the aryl-hydrocarbon receptor (AhR) and the AhR nuclear translocator (ARN). Recently, the interference of AhR-ARNT with the nuclear factor (NF)-kappaB signaling pathway has been proposed as a critical event in the adverse effects on the immune system. Studies on the effects of these AhR-ARNT-related toxicants on the immune system of higher and lower phylum animals and knowledge of intracellular mechanisms of toxicity may contribute to development of biomarkers of ecotoxicant exposure and effects. Biomarkers of this kind allow sampling over extended geographic areas, in several sentinel species, including wildlife animals, and facilitate the building of risk models and risk maps of environmentally induced diseases. On the basis of location, biomarker sampled data obtained through evaluation of ecotoxicant exposure and effects on the immune system in sentinel species can be further integrated and analyzed together with other sources of environmental geographic information, or human population health data, by means of geographic information systems (GIS). The spatial analysis capability of GIS can help to evaluate the complex relationships of overlaid information and to identify areas with high risk indices or "hot spots." This integrative approach can be useful in studies contributing to support environmental and health-related policies and regulations.