Autistic traits,ADHD symptoms,neurological soft signs and regional cerebral blood flow in adults with autism spectrum disorders

The resting regional cerebral blood flow (rCBF) patterns related to co-occurring symptoms such as inattention, hyperactivity, neurological soft signs and motor problems have not yet been disclosed in autism spectrum disorders (ASD). In this study thirteen adults with ASD and ten matched neurotypical controls underwent PET. The scores of rating scales for autistic traits, attention deficit hyperactivity disorder (ADHD) and neurological soft signs were included in a factorial analysis and correlated with rCBF. Factors corresponding to \u27\u27autistic/ADHD traits\u27\u27, \u27\u27sensory-motor integration\u27\u27 and \u27\u27Intelligence/Motor sequencing\u27\u27 were identified. In the ASD group, positive correlations with CBF were found for \u27\u27autistic/ADHD traits\u27\u27 in caudate bilaterally and the inferior parietal lobule, for \u27\u27sensory-motor integration\u27\u27 in parieto-occipital cortex and for \u27\u27Intelligence/Motor sequencing\u27\u27 in the right temporal cortex. Notably, CBF in the left thalamus correlated negatively with all three factors. Autistic traits and ADHD symptoms were associated with shared neural substrates. The correlation between \u27\u27autistic/ADHD traits\u27\u27 and rCBF in the caudate is possibly associated with the executive impairments and ritualistic/stereotyped behaviors apparent in ASD. Furthermore, sensory-motor deficits were correlated with rCBF in the occipital visual cortex, involved in atypical visual perception in ASD. Various behavioral and neurological symptoms are suggested to converge into the ASD phenotype

The pigmented life of a redhead.

As a redhead I have had a personal interest in red hair, freckles and sunburns since childhood. An observation of a formaldehyde-induced fluorescence in human epidermal melanocytes initiated my scientific interest in these cells. Prota and Nicolaus demonstrated that oxidation products of cysteinyldopas are the main components of pheomelanin. Our identification of 5-S-cysteinyldopa as the source of formaldehyde-induced fluorescence of normal and pathological melanocytes started a series of investigations into this amino acid, enzymatic and non-enzymatic oxidation of catecholic compounds and the metabolism of thiols. All melanocytes with functioning tyrosinase produce cysteinyldopas and the levels of 5-S-cysteinyldopa in serum and urine are related to the size and pigment forming activity of the melanocyte population. The determination of 5-S-cysteinyldopa in serum or urine is a sensitive diagnostic method in the detection of melanoma metastasis. Some non-specific formation of cysteinyldopa is present in the body, as demonstrated by 5-S-cysteinyldopa in individuals with tyrosinase-negative albinism

The surface oxidation potential of human neuromelanin reveals a spherical architecture with a pheomelanin core and a eumelanin surface

Neuromelanin (NM) isolated from the substantia nigra region of the human brain was studied by scanning probe and photoelectron emission microscopies. Atomic force microscopy reveals that NM granules are comprised of spherical structures with a diameter of ≈30 nm, similar to that observed for Sepia cuttlefish, bovine eye, and human eye and hair melanosomes. Photoelectron microscopy images were collected at specific wavelengths of UV light between 248 and 413 nm, using the spontaneous-emission output from the Duke OK-4 free electron laser. Analysis of the data establishes a threshold photoionization potential for NM of 4.5 ± 0.2 eV, which corresponds to an oxidation potential of −0.1 ± 0.2 V vs. the normal hydrogen electrode (NHE). The oxidation potential of NM is within experimental error of the oxidation potential measured for human eumelanosomes (−0.2 ± 0.2 V vs. NHE), despite the presence of a significant fraction of the red pigment, pheomelanin, which is characterized by a higher oxidation potential (+0.5 ± 0.2 V vs. NHE). Published kinetic studies on the early chemical steps of melanogenesis show that in the case of pigments containing a mixture of pheomelanin and eumelanin, of which NM is an example, pheomelanin formation occurs first with eumelanin formation predominantly occurring only after cysteine levels are depleted. Such a kinetic model would predict a structural motif with pheomelanin at the core and eumelanin at the surface, which is consistent with the measured surface oxidation potential of the ≈30-nm constituents of NM granules