Differential habituation to repeated sounds in infants at high risk for autism

It has been suggested that poor habituation to stimuli might explain atypical sensory behaviours in autism. We investigated habituation to repeated sounds using an oddball paradigm in 9-month-old infants with an older sibling with autism and hence at high risk for developing autism. Auditory-evoked responses to repeated sounds in control infants (at low risk of developing autism) decreased over time, demonstrating habituation, and their responses to deviant sounds were larger than responses to standard sounds, indicating discrimination. In contrast, neural responses in infants at high risk showed less habituation and a reduced sensitivity to changes in frequency. Reduced sensory habituation may be present at a younger age than the emergence of autistic behaviour in some individuals, and we propose that this could play a role in the over responsiveness to some stimuli and undersensitivity to others observed in autism.     

Postnatal weight gain modifies severity and functional outcome of oxygen-induced proliferative retinopathy

In clinical studies, postnatal weight gain is strongly associated with retinopathy of prematurity (ROP). However, animal studies are needed to investigate the pathophysiological mechanisms of how postnatal weight gain affects the severity of ROP. In the present study, we identify nutritional supply as one potent parameter that affects the extent of retinopathy in mice with identical birth weights and the same genetic background. Wild-type pups with poor postnatal nutrition and poor weight gain (PWG) exhibit a remarkably prolonged phase of retinopathy compared to medium weight gain or extensive weight gain pups. A high (r(2) = 0.83) parabolic association between postnatal weight gain and oxygen-induced retinopathy severity is observed, as is a significantly prolonged phase of proliferative retinopathy in PWG pups (20 days) compared with extensive weight gain pups (6 days). The extended retinopathy is concomitant with prolonged overexpression of retinal vascular endothelial growth factor in PWG pups. Importantly, PWG pups show low serum levels of nonfasting glucose, insulin, and insulin-like growth factor-1 as well as high levels of ghrelin in the early postoxygen-induced retinopathy phase, a combination indicative of poor metabolic supply. These differences translate into visual deficits in adult PWG mice, as demonstrated by impaired bipolar and proximal neuronal function. Together, these results provide evidence for a pathophysiological correlation between poor postnatal nutritional supply, slow weight gain, prolonged retinal vascular endothelial growth factor overexpression, protracted retinopathy, and reduced final visual outcome.     

Serum Vascular Endothelial Growth Factors A, C and D in Human Breast Tumors

Available evidence suggests that vascular endothelial growth factor (VEGF) a potent regulator of vasculogenesis and tumor angiogenesis may be a predictor of recurrence in breast cancer patients. We sought to determine whether VEGF serum levels (VEGF-A, VEGF-C and VEGF-D) in 377 patients with malignant and benign breast tumors differ and whether there is association between vascular growth factors, clinicopathologic features and prognosis. There was no significant difference in investigated circulating angiogenic markers between patients with malignant and non malignant lesions. We found strong correlation between VEGF-A and VEGF-D and between VEGF- C and VEGF-D. Besides serum VEGF-D levels and estrogen receptor (ER) expressions no other correlations between VEGF and clinicopathologic variables were observed. However, elevated VEGF-A and VEGF-C concentrations were associated with increased number of erythrocytes, leukocytes and platelets. In Cox model values of angiogenic serum markers and recognized prognostic markers in breast cancer, VEGF-C turned out as independent prognostic factor. Our study is the first analysis showing correlation between serum concentrations of three angiogenic factors: VEGF-A, VEGF-C, VEGF-D. Associations between angiogenic cytokines and number of blood cells may be due to release of VEGF from platelets and leucocytes. Prognostic role of VEGF is still uncertain, though VEGF-C has a potential to serve as a prognostic marker.     

Pheomelanin in the skin of Hymenochirus boettgeri (Amphibia: Anura: Pipidae)

Pheomelanin is supposed to be the first type of melanin found in vertebrates, in contrast to the main type - eumelanin. Our study aimed at detecting pheomelanin in the skin of Hymenochirus boettgerii. We employed electron paramagnetic resonance (EPR) spectroscopy, and transmission electron microscopy (TEM), supplemented with standard histology and immunochemistry. We identified pheomelanin in the dorsal skin of adult frogs (not only in the dermis, but also in the epidermis) and in the dorsal tadpole. Our work identifies Hymenochirus boettgerii as a model in the basic study on the mechanism, evolution and role of melanogenesis in animals, including human.