Human impulsive aggression: a sleep research perspective

Impulsive aggression is commonly associated with personality disorders, in particular antisocial and borderline personality disorders as well as with conduct disorder and intermittent explosive disorder. The relationship between impulsive aggression and testosterone is well established in many studies. One of the aims of this study was to characterize the relationship between earlier-mentioned different categorical psychiatric diagnosis describing human impulsive aggression and sleep using polysomnography and spectral power analysis. Another aim was to study the relationship between serum testosterone and sleep in persons with severe aggressive behaviour. Subjects for the study were 16 males charged with highly violent offences and ordered for a pretrial forensic psychiatric examination. The antisocials with borderline personality disorder comorbidity had significantly more awakenings and lower sleep efficiency compared with the subjects with only antisocial personality disorder. The subjects with severe conduct disorder in childhood anamnesis had higher amount of S4 sleep and higher relative theta and delta power in this sleep stage compared with males with only mild or moderate conduct disorder. The same kind of sleep architecture was associated with intermittent explosive disorder. In subgroups with higher serum testosterone levels also the amount of S4 sleep and the relative theta and delta power in this sleep stage were increased. The study gives further support to the growing evidence of brain dysfunction predisposing to severe aggressive behaviour and strengthens the view that there are different subpopulations of individuals with antisocial personality varying in impulsiveness. The differences in impulsiveness are reflected in sleep architecture as well.     

Absence of alphavbeta6 integrin is linked to initiation and progression of periodontal disease

Integrin alphavbeta6 is generally not expressed in adult epithelia but is induced in wound healing, cancer, and certain fibrotic disorders. Despite this generalized absence, we observed that alphavbeta6 integrin is constitutively expressed in the healthy junctional epithelium linking the gingiva to tooth enamel. Moreover, expression of alphavbeta6 integrin was down-regulated in human periodontal disease, a common medical condition causing tooth loss and also contributing to the development of cardiovascular diseases by increasing the total systemic inflammatory burden. Remarkably, integrin beta6 knockout mice developed classic signs of spontaneous, chronic periodontal disease with characteristic inflammation, epithelial down-growth, pocket formation, and bone loss around the teeth. Integrin alphavbeta6 acts as a major activator of transforming growth factor-beta1 (TGF-beta1), a key anti-inflammatory regulator in the immune system. Co-expression of TGF-beta1 and alphavbeta6 integrin was observed in the healthy junctional epithelium. Moreover, an antibody that blocks alphavbeta6 integrin-mediated activation of TGF-beta1 initiated inflammatory periodontal disease in a rat model of gingival inflammation. Thus, alphavbeta6 integrin is constitutively expressed in the epithelium sealing the gingiva to the tooth and plays a central role in protection against inflammatory periodontal disease through activation of TGF-beta1.     

Post‐trial costs,clinical outcomes,and dental service utilization after a randomized clinical trial for caries control among Finnish adolescents

Hietasalo P, Seppä L, Niinimaa A, Kallio J, Lahti S, Hausen H. Post‐trial costs, clinical outcomes, and dental service utilization after a randomized clinical trial for caries control among Finnish adolescents. Eur J Oral Sci 2010; 118: 265–269. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci The aim of this study was to assess post‐trial treatment costs, clinical outcomes [decayed, missing or filled surfaces (DMFS) scores], and utilization of dental services among adolescents who had participated in a randomized clinical trial (RCT) in Pori, Finland, in 2001–2005. At baseline the children were 11–12 yr of age and had had at least one active initial caries lesion. The children in the experimental group (n = 250) had been exposed to multiple measures for caries control, while those in the control group (n = 247) had received standard dental care. During the post‐trial period (2005–2008), all participants received the standard dental care offered in public dental clinics in Pori. In both groups the costs of treatment procedures and outcomes for the post‐trial period were calculated for each adolescent. Information from patient records was available for 487 adolescents (former experimental n = 246, control n = 241). The mean total costs per adolescent were lower and the clinical outcome was better among the former experimental‐group participants. The differences in mean costs between the groups were statistically significant for preventive and restorative procedures. The utilization of dental services was significantly more regular among the former experimental‐group participants.     

Chromosomal aberrations in railroad transit workers: Effect of genetic polymorphisms

Complex chemical mixtures are transported by train from Russia to Finland for further shipment. Here, we studied if exposure to genotoxic components among these substances could affect chromosomal aberrations (CAs) in peripheral lymphocytes of workers handling the tank cars. An initial survey among 48 railroad workers and 39 referents (male smokers and nonsmokers) showed an elevation of CAs. A campaign was started to reduce exposures through preventive measures. Five years later, 51 tank car workers and 40 age‐matched referents (all nonsmoking men) were studied for CAs and genetic polymorphisms of xenobiotic metabolism (EPHX1, GSTM1, GSTP1, GSTT1, NAT1, NAT2), DNA repair (ERCC2, ERCC5, XPA, XPC, XRCC1, XRCC3), and folate metabolism (MTHFR, MTR). No increase in CAs was seen in the exposed group, suggesting that the preventive measures had been successful. However, a positive association existed between exposure duration and CA level among the exposed subjects. The level of chromosome‐type breaks was actually lower in the exposed workers than the referents, particularly among MTHFR wild‐type homozygotes or XRCC3 codon 241 variant allele carriers, suggesting modulation of CA frequency by folate metabolism and DNA repair. An interaction was observed between the occupational exposure and MTHFR, EPHX1, and MTR genotypes in determining CA level. The NAT2, ERCC2 exon 10, and XRCC1 codon 194 polymorphisms also affected CA frequency. Our findings suggest that handling of tank cars containing complex chemical mixtures poses a genotoxic risk, which may be reduced by preventive measures. Several genetic polymorphisms seem to modify the genotoxic effect or baseline CA level. Environ. Mal. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.