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Biomedical subjects

A Forsman

Publications and source records attributed to A Forsman.

At least 19 recordsLinked to original sources
PubMed2005

Increased CSF/serum albumin ratio: a recurrent finding in violent offenders.

OBJECTIVE: To test the hypothesis that cerebrospinal fluid (CSF)/ serum albumin ratios are increased in violent offenders. SUBJECTS AND METHODS: In a previous study of violent offenders, we found significantly higher CSF/serum album ratios (as a sign of increased blood-brain barrier permeability) in violent offenders than in healthy controls. For the present replication study, we recruited a new group of 28 violent offenders, aged 45 years or younger, and 20 new control subjects. RESULTS: The albumin ratio was again significantly higher in the offender group (mean 6.2) than in the control group (mean 4.6) (P = 0.012). Substance abuse or current medication did not appear to explain this finding. CONCLUSION: Increased CSF/serum albumin ratios are an unspecific sign of neurological dysfunction in subgroups of violent offenders.

Adolescent↗
PubMed2004

Elevated triiodothyronine in psychopathy - possible physiological mechanisms.

We assessed a total range of peripheral thyroid hormone fractions, binding globulins, and thyroid-active antibodies in 37 medication-free, violent or sexual offenders, aged 17-45 years, to describe possible mechanisms involved in the thyroid metabolism of aggressive men. The ratio between T3 and T4 correlated with ratings of psychopathy, indicating increased peripheral deiodination as a biological covariate to callous personality traits. Autoimmune antibodies, hepatic failure, abnormal binding globulins, or substance abuse did not affect the association.

Adolescent↗
PubMed2004

A controlled study of tryptophan and cortisol in violent offenders.

Changes in the metabolism of tryptophan, other amino acids, and steroid hormones have been implicated in aggression. We compared tryptophan, competing long amino acids (CAAs), and cortisol in serum (S) and CSF in 22 violent offenders and 15 healthy controls. Offenders had significantly increased S-L-tryptophan, S-free tryptophan, S-CAAs, S-cortisol and CSF-cortisol, indicating abnormal neurophysiological processes. Larger studies on the interplay between violence, serotonin precursors, and stress hormones need to integrate personality traits, life situations, and physiological adaptation.

Adolescent↗
PubMed2003

Uptake of amplifiable fragments of retrotransposon DNA from the human alimentary tract.

Few attempts have been made to study the transfer of DNA from ingested food across the intestinal barrier. A low uptake of ingested DNA has been observed in mice, cattle and poultry. There have been no reports on humans so far. Maintenance of species barriers, protection against retrotransposons, optimisation of oral DNA vaccines and the fate of genetically modified foodstuffs are issues where this topic is of importance. We therefore used the high-copy-number rabbit retrotransposon RERV-H, and rabbit mitochondrial DNA, to study the transfer of DNA from ingested rabbit meat into the bloodstream of two human volunteers. A quantitative PCR was used to measure RERV-H levels in food and in the blood. Amplification with the primers selected results in the generation of a 250-bp fragment of RERV-H. Transfer across the intestinal epithelium could be demonstrated in both subjects. Levels of the fragment in the bloodstream peaked at 1-3 h after ingestion of the experimental meal. One hour after a meal of rabbit meat containing 10(14) copies of RERV-H DNA, a maximum concentration of 200 copies of RERV-H DNA per ml of peripheral blood was observed, which corresponds to the uptake of approximately 10(6) RERV-H DNA copies in 1 h. RERV-H DNA was detected in both cellular and plasma compartments. Both rabbit retrotransposon and mitochondrial DNA was taken up from the human alimentary tract. The size of the fragments detected is similar to that of SINE retrotransposons (approximately 300 bp). The fate and functionality of alimentary DNA in humans will require further study.

Administration, Oral↗
PubMed2003

The activity in the CNS catecholaminergic systems covaries with thyroid hormone metabolism in humans.

Do the CNS monoaminergic (MA) systems regulate thyroid hormone metabolism in humans? In 23 unmedicated, male, violent offenders without signs of thyroid disease, we found positive correlations between the catecholaminergic CSF metabolites HVA and MHPG and the peripheral T3/T4 ratio (rho=0.55, p=0.010 and 0.51, p=0.018), indicating that increased activity in the brain MA systems, especially the dopaminergic, is associated with increased peripheral thyroid hormone activity.

Adult↗
PubMed2003

Correlated evolution of colour pattern and body size in polymorphic pygmy grasshoppers, Tetrix undulata.

Theory posits that selection on functionally interrelated characters will promote physical and genetic integration resulting in evolution of favourable trait-value combinations. The pygmy grasshopper Tetrix undulata (Orthoptera: Tetrigidae) displays a genetically encoded polymorphism for colour pattern. Colour morphs differ in several traits, including behaviours, thermal biology and body size. To examine if these size differences may reflect phenotypic plasticity of growth and development in response to temperature we used a split brood-design and reared hatchlings from mothers belonging to different morphs in different thermal environments (warm or cold) until maturity. We found that time to maturity was longer in the cold compared with the warm treatment. In the warm (but not in the cold) treatment time to maturity also varied among individuals born to mothers belonging to different colour morphs. Although low temperature and long development time are normally accompanied by increased body size in ectotherms, our results revealed no difference in size at maturity between individuals reared in the two temperature treatments. There was also an increase (not a decrease) in adult body size with shortened time to maturity across families within each treatment. Taken together, this suggests that body size is canalized against environmental perturbations, and that early maturation does not necessarily trade off against a size-mediated decrease in fecundity. Heritability of body size was moderate in magnitude. Moreover, body size at maturity varied among individuals belonging to different morphs and was influenced also by maternal colour morph, suggesting that a genetic correlation exists between colour pattern and body size. These findings suggest that different characters have evolved in concert and that the various colour morphs represent different evolutionary strategies, i.e., alternative peaks in a multi-modal adaptive landscape.

Adaptation, Physiological↗
PubMed2003

New evidence for an association between the CSF HVA:5-HIAA ratio and psychopathic traits.

OBJECTIVES: To replicate the relation between the CSF HVA:5-HIAA ratio and psychopathic traits previously reported in a pilot group of 22 perpetrators of violent crimes. METHODS: CSF monoamine metabolite concentrations in another 28 violent and sexual offenders, aged 45 or below, referred to pretrial forensic psychiatric investigation, were compared to features of psychopathy according to the Psychopathy Checklist-Revised (PCL-R). RESULTS: Our previous finding was repeated in the new study group, where the HVA:5-HIAA ratio was strongly associated with psychopathic traits (r = 0.50, p = 0.010), particularly its behavioural aspects (r = 0.523, p = 0.004). In subsamples of individuals from both study groups who had no medication (n = 25) or no current axis I disorder, including a history of mood disorder or substance dependence (n = 21), the HVA:5-HIAA ratio remained strongly associated with all psychopathy factors but most closely with the behavioural features. Retrospective assessments of childhood disruptive symptomatology, such as attention deficit hyperactivity disorder or conduct disorder, analysed in relation to the monoamine metabolites, showed the same association with the HVA:5-HIAA ratio. CONCLUSIONS: Violent and aggressive behavioural traits with childhood onset and adult expression as psychopathic features are associated with changed activity in the brain dopaminergic system, possibly as a result of serotonergic dysregulation.

Adolescent↗
PubMed2001

CSF studies in violent offenders. I. 5-HIAA as a negative and HVA as a positive predictor of psychopathy.

Low serotonin activity in man has been related to impulsive, self-destructive violence but not to instrumental aggression aimed at dominance. A relationship has also been suggested between aggression and high catecholaminergic activity. Several studies have reported signs of aberrant dopaminergic function in attention deficit hyperactivity disorder, autism, and schizophrenia. In 22 violent offenders undergoing pretrial forensic psychiatric investigation, interpersonal and behavioral features of psychopathy, measured by the Psychopathy Checklist Revised (PCL-R), were significantly predicted by low cerebrospinal fluid (CSF) concentrations of 5-HIAA and high CSF concentrations of HVA in multivariate regression models. CSF concentrations of MHPG did not contribute to the model. This seems to link the outward-directed aggression of psychopathy to serotonergic hypofunctioning and high dopamine turnover, which might account for disinhibition of destructive impulses.

Adolescent↗
PubMed2001

CSF studies in violent offenders. II. Blood-brain barrier dysfunction without concurrent inflammation or structure degeneration.

Cerebral dysfunction without corresponding structural pathology has been reported in brain imaging studies of violent offenders. Biochemical markers in the CSF reflect various types of CNS pathology, such as blood-brain barrier dysfunction (CSF/S albumin ratio), infectious or inflammatory processes (IgG and IgM indices), neuronal or axonal degeneration (CSF-tau protein) and synaptic de- or regeneration (CSF-growth associated protein-43 (GAP-43)). We compared these CSF markers in 19 non-psychotic perpetrators of severe violent crimes undergoing pretrial forensic psychiatric investigation and 19 age- and sex-matched controls. Index subjects had significantly higher albumin ratios (p = 0.002), indicating abnormal vascular permeability as part of the complex CNS dysfunction previously reported in violent offenders. Axis I disorders, including substance abuse or current medication, did not explain this finding. Since Ig-indices, CSF-tau protein or CSF-GAP-43 were not increased, there was no support for inflammation or neuronal/synaptic degeneration as etiological factors to CNS dysfunction in this category of subjects.

Adolescent↗
PubMed2001

A deficit in attentional set-shifting of violent offenders.

BACKGROUND: Recent brain imaging studies suggest that proneness to violence and antisocial behaviour may be associated with dysfunction of the prefrontal cortex. The present study. therefore, examined aspects of prefrontally guided executive functions in a group of criminal violent men. METHODS: Violent offenders undergoing forensic psychiatric examination by court order undertook computerized tasks for planning, visual working memory and attentional set-shifting from the Cambridge Neuropsychological Test Automated Battery. Their performance was compared to that of subjects with marginal mental retardation and normal controls. RESULTS: Violent offenders performed well on tasks for spatial and figurative working memory, as well as on a test for planning. A marked impairment was observed in the attentional set-shifting task: offenders made significantly more errors than the other groups when required to shift attention from one perceptual dimension to another. Reversal learning was also deficient. Correlational analyses within the offender group revealed that poor performance on the perceptual shift problem was associated with fewer errors in tasks for working memory and planning. CONCLUSIONS: The present results suggest that violent offenders show dual impairments in inhibitory cognitive control. First, they are deficient in shifting attention from one category to another. Secondly, the ability to alter behaviour in response to fluctuations in the emotional significance of stimuli is compromised. These deficits might constitute cognitive reflections of the biological prefrontal alterations observed in this group of people.

Adolescent↗
PubMed2001

Sexual child abuse in a defined Swedish area 1993-97: a population-based survey.

Attempting to avoid some of the most common methodological problems involved in research on sexual child abuse, we collected data on crimes, perpetrators, and sanctions in all convicted cases of sexual child abuse in a defined population during a 5-year period. This approach provided amply documented and ascertained cases with precise definitions and descriptions of the crimes involved, no clinical referral bias, and minimal dependence on memory effects. The results are valid for the small proportion of cases that lead to conviction in the context of Swedish legislation. Structured data were collected from the court dossiers in all cases of sexual crimes against minors (less than 15 years of age) tried and sentenced at the courts in the Västra Götaland region of Sweden between 1993 and 1997. The total number of 496 sentences for sexual crimes during the study period included 203 cases of sexual child abuse (40.8%) with 283 victims and 196 perpetrators, all men. Girls were victims in 85% of the cases, boys in 12%, and boys as well as girls in 3%. Sexual penetration had occurred in 54.5% of cases and the total proportion of hands-on crimes was 83%. Most perpetrators, 72%, were well known to the child. The most severe offenses took place within the family. A wide range of acts were classified as sexual child abuse, but most common was sexual penetration of a female child by her biological father or a family friend.

Adolescent↗
PubMed2000

Reduced regional cerebral blood flow in non-psychotic violent offenders.

The present study was designed to replicate previously reported findings of abnormal frontal and/or temporal cerebral blood flow in violent offenders and to control for the influence of major mental disorder (MMD), substance abuse, and current medication. HMPAO-SPECT-CBF and MRI scans from pretrial forensic psychiatric investigations of 21 subjects convicted of impulsive violent crimes were retrospectively re-evaluated. In 16/21 subjects, visual assessment of SPECT scans showed some hypoperfusion in the temporal and/or frontal lobes. MRI showed no corresponding structural damage. Quantified regional cerebral blood flow (rCBF) in defined regions of interest was compared between index cases and 11 healthy control subjects. Index subjects had significant reductions in the right angular gyrus and the right medial temporal gyrus, bilaterally in the hippocampus, and in the left white frontal matter, but they had significantly increased rCBF in the parietal association cortex bilaterally. The aberrations were as frequent and severe among the subjects without MMD, substance abuse, and current medication (n=7) as in the entire group of index subjects.

Adolescent↗
PubMed2000

Approaches in the determination of plant nutrient uptake and distribution in space flight conditions.

The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

Autoradiography↗
PubMed1994

Schizophrenia and sex chromosome anomalies.

An apparent excess of sex chromosome aneuploidies (XXY, XXX, and possibly XYY) has been reported in populations of patients with schizophrenia by a number of authors. These reports have received little attention because transmission of psychosis is regarded as autosomal and not sex linked, and the detection of extra X chromosomes by Barr body estimation alone is not a reliable procedure. In this article, we review studies in which either complete karyotypes were determined for the whole sample or in which the presence of a Barr body in an individual was checked by full cytogenetic analysis. We also add two studies (of the former type) of our own--on a Swedish hospital cohort and a United States multiplex-schizophrenia family sample. These data, taken together, suggest that the sex chromosome aneuploidies, XXX and XXY, are increased in population of patients with schizophrenia, whereas too few subjects have been surveyed to determine whether an association also exists with XYY. Nevertheless, we conclude that this is consistent with a gene on the sex chromosomes having influence on the development of schizophrenia. A sex chromosome locus is compatible with an autosomal pattern of transmission if the gene is either pseudoautosomal (i.e., within the exchange region) or X-Y homologous (i.e., present in similar form in the nonrecombining regions of both X and Y chromosomes).

Adult↗