Frits-axel Wiesel

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BACKGROUND Tyrosine supplementation in humans has been shown to improve cognitive functioning. Several studies have demonstrated a decreased maximal transport capacity of tyrosine (Vmax) across the cell membrane and an increased affinity (Km) of tyrosine to membrane binding sites in schizophrenic patients. A lack of tyrosine for dopamine synthesis with(More)
BACKGROUND Subsidiary findings in several studies indicate that the standard summary scores (total number of needs, met needs and unmet needs) of the Camberwell Assessment of Need (CAN) may conceal important differences among patient populations at the item level of the measure. The aim of this study was to investigate whether changes in need and need(More)
Aberrant tyrosine transport across the fibroblast membrane, as measured by lower Vmax and/or lower Km is a repeated finding in patients with schizophrenia. The aim of this study was to investigate the importance of two major transporters, the L- and A-systems and tyrosine transport in fibroblast cell lines from patients with schizophrenia and healthy(More)
OBJECTIVE To further evaluate the controversial putative association between a Ser9Gly variant in the first exon of the dopamine D3 receptor gene (DRD3) and schizophrenia. METHODS Swedish patients with schizophrenia ( n=156) and control subjects ( n=463) were assessed for the DRD3 Ser9Gly variant. Meta-analyses including previous and the present Swedish(More)
Several mechanisms have been suggested to account for altered dopaminergic neurotransmission in schizophrenia. The brain is the only organ for which amino-acid transport is limited and competition for transport over the blood-brain barrier (BBB) occurs at physiological plasma concentrations. One line of research suggests that patients with schizophrenia(More)
We present the Need of Support and Service Questionnaire (NSSQ), a new instrument developed to provide professionals in psychiatric care and community social services with a tool to assess needs of support and service in mentally disabled clients. The final version of the instrument was designed after comments from professionals in psychiatric care,(More)
BACKGROUND In order to define needs for care of people with severe mental illness, the Camberwell Assessment of Need (CAN) is focused on measuring personal and social functioning. However, previous studies of the CAN have given inconsistent results in terms of what variables are actually being measured. AIMS To investigate the factor structure of the CAN.(More)
Autism is a developmental, cognitive disorder clinically characterized by impaired social interaction, communication and restricted behaviours. The present study was designed to explore whether an abnormality in transport of tyrosine and/or alanine is present in children with autism. Skin biopsies were obtained from 11 children with autism (9 boys and 2(More)
Human fibroblast cells are an advantageous model to study the transport of amino acids across cell membranes, since one can control the environmental factors. A major problem in all earlier studies is the lack of precise and detailed knowledge regarding the expression and functionality of tyrosine transporters in human fibroblasts. This motivated us to(More)
OBJECTIVE Disturbances in catecholamine transmission have been implicated in schizophrenia. Dopamine beta-hydroxylase catalyses the conversion of dopamine to norepinephrine in noradrenergic cells. We attempted to investigate a putative functional promoter polymorphism in the dopamine beta-hydroxylase gene (DBH) for association with schizophrenia. METHODS(More)