Covert matching of unfamiliar faces in a case of prosopagnosia: an ERP study

In addition to their deficit in overt face recognition, patients with prosopagnosia also have difficulties in matching sequentially presented unfamiliar faces. Here we assessed the possibility that covert matching of faces was present in a case with prosopagnosia using event-related potentials (ERPs). The participants (patient FE and normal controls) were challenged with a face-identity matching task, in which they decided whether two sequentially presented photographs of unfamiliar faces represented the same person. Only internal face features were used and the two faces in a pair differed in emotional expression. FE failed to overtly match these stimuli. In contrast, the ERPs revealed evidence of covert matching. If the two faces within a pair of stimuli depicted different posers, then the response to the second face contained an enhanced N300 compared to the situation where the identity of the faces was the same. The latency of the N300 was the same as a similar component found in controls. These results suggest that some cases with prosopagnosia have a covert ability to match unfamiliar faces, with similar temporal dynamics as controls, which in contrast with the idea that a generalized slowing of face processing occurs in all cases of prosopagnosia.     

Directional and fluctuating asymmetry in finger and <Emphasis Type="Italic">a-b</Emphasis> ridge counts in psychosis: a case-control study

Background  

Several studies have reported alterations in finger and a-b ridge counts, and their derived measures of asymmetry, in schizophrenia compared to controls. Because ridges are fully formed by the end of the second trimester, they may provide clues to disturbed early development. The aim of this study was to assess these measures in a sample of patients with psychosis and normal controls.     

Conantokin-L,a new NMDA receptor antagonist: determinants for anticonvulsant potency

Conantokins are N-methyl-D-aspartate receptor antagonist peptides found in the venoms of marine cone snails. Current intense interest in this peptide family stems from the discovery of their therapeutic potential as anticonvulsants. It was recently reported that conantokin-R is a highly potent anticonvulsant compound, with a protective index of 17.5 when tested in the audiogenic mouse model of epilepsy. Conantokin-L was characterized from Conus lynceus and found to have extensive homology with conantokin-R, except For the C-terminal amino acids. Although conantokin-L appears almost as potent as conantokin-R in standard in vivo assays for conantokins and NMDA receptor binding assays, it is far less potent as an anticonvulsant, with a protective index of 1.2 in the audiogenic mouse model. The results suggest that the C-terminal sequences of conantokin-R and conantokin-L are a major determinant of their anticonvulsant potency.     

Variations in the number of births by day of the week,and morbidity and mortality in very-low-birth-weight infants

Objective

To know the distribution of births of very low birth weight infants by day of the week, and whether this distribution affects the morbidity and mortality in this group of patients.

Plasminogen activator inhibitor-1 in girls with precocious pubarche: a premenarcheal marker for polycystic ovary syndrome?

In both obese and nonobese women, polycystic ovary syndrome (PCOS) is essentially a disorder of hyperinsulinemic insulin resistance, and it may be heralded by precocious pubarche (PP; appearance of pubic hair in girls aged <8 y). The risk of progression from PP to PCOS is related to low birth weight, but there are no early biochemical markers of this risk. As increased plasminogen activator-inhibitor type 1 (PAI-1) activity (act) is an early marker of cardiovascular risk in PCOS, we have sought abnormalities in young girls with PP. In 33 young PP girls (age range 6-11 y), PAI-1-act was increased (mean + SEM: 15.6 +/- 1.5 IU/mL) compared with age-, sex-, and pubertal stage-matched controls (n = 13, 10.7 +/- 1.9, p < 0.05). PAI-1-act levels were inversely related to birth weight SD score (r = -0.33, p < 0.05), and PAI-1-act levels were therefore higher in PP girls with low birth weights (n = 14, 19.5 +/- 2.5 IU/mL) than normal birth weights (n = 19, 12.8 +/- 1.5, p < 0.01). During longitudinal observation in 10 PP girls (mean time interval 2.7 y), PAI-1-act levels in early puberty were positively related to postmenarcheal insulin levels (mean serum insulin SDS postoral glucose, r = 0.65, p < 0.05), and showed a similar relationship to postmenarcheal testosterone levels (r = 0.61, p = 0.06). Together with low birth weight, increased plasma PAI-1-act levels in early pubertal PP girls may indicate those girls with greater risk of developing hyperinsulinemic-hyperandrogenism features of PCOS.     

Further evidence that congenital dermatoglyphic abnormalities are associated with psychosis: a twin study

The presence of abnormal palmar flexion creases (APFC) and dermatoglyphic ridge dissociation (RD) may constitute enduring evidence of a prenatal insult that occurred before the third trimester of intrauterine life. We examined these dermatoglyphic abnormalities in a twin study of psychotic disorders. RD and APFC were analyzed in a monozygotic (MZ) twin sample from the Maudsley Hospital in London (11 normal control pairs, 16 pairs concordant for psychosis, 9 pairs discordant for psychosis, 1 concordant triplet, and 1 triplet with one affected member). The risk of either RD or APFC was 44 percent in affected twins and 20 percent in nonaffected twins (odds ratio = 3.25, 95% confidence interval: 1.03-10.31; one-sided p = 0.023). In the group of MZ twins discordant for psychosis, discordance for RD or APFC always paralleled discordance for psychosis (one-sided p = 0.078), suggesting the operation of nongenetic factors. The results confirm previous work suggesting the possibility that nongenetic factors early in pregnancy contribute to the liability to develop psychosis in later life.