Recombination in Tula hantavirus evolution: analysis of genetic lineages from Slovakia

To examine the evolution of Tula hantavirus (TUL), carried by the European common vole (Microtus arvalis and M. rossiaemeridionalis), we have analyzed genetic variants from Slovakia, the country where the virus is endemic. Phylogenetic analysis (PHYLIP) based on either partial (nucleotides [nt] 441 to 898) or complete N-protein-encoding sequences divided Slovakian TUL variants into two main lineages: (i) strains from eastern Slovakia, which clustered with Russian strains, and (ii) strains from western Slovakia situated closer to those from the Czech Republic. We found genetic diversity of 19% between the two groups and 4% within the western Slovakian TUL strains. Phylogenetic analysis of the 3' noncoding region (3'-NCR), however, placed the eastern Slovakian strains closer to those from western Slovakia and the Czech Republic, with a greater distance to the Russian strains, suggesting a recombinant nature of the S segment in the eastern Slovakian TUL lineage. A bootscan search of the S-segment sequences of TUL strains revealed at least two recombination points in the S sequences of eastern Slovakian TUL strains (nt 400 to 415 and around 1200) which agreed well with the pattern of amino acid substitutions in the N protein and deletions/insertions in the 3'-NCR of the S segment. These data suggest that homologous recombination events occurred in the evolution of hantaviruses.     

Developmental differences in rule learning: a microgenetic analysis

Trial-by-trial strategy assessments and a microgenetic design were used to examine 4- and 5-year-olds' learning of rules for solving balance scale problems. The design allowed us to examine simultaneously the contribution to rule learning of distal variables (qualities and knowledge with which children enter the learning situation) and proximal variables (processes that they execute during learning). Developmental differences in learning arose through two distal variables that were correlated with age--initial rule use and initial encoding-helping older children to execute several proximal processes--noticing the potential explanatory role of a key variable, formulating a more advanced rule, and generalizing and maintaining the rule. Joint consideration of distal and proximal influences seems likely to be generally useful for understanding learning and development.     

cDNA sequence analysis and expression of four long neurotoxin homologues from Naja naja atra

A rapid and simple method is presented for the determination of vigabatrin enantiomers in human serum by high-performance liquid chromatography. Serum is deproteinized with trichloroacetic acid and aliquots of the supernatant are precolumn derivatized with o-phthaldialdehyde and N-acetyl-L-cysteine, resulting in the formation of diastereomeric isoindoles. Separation was achieved on a Spherisorb 3ODS2 column using a gradient solvent program and the column eluent is monitored using fluorescence detection. L-Homoarginine was used as an internal standard. Within-day precisions (C.V.; n=8) were 2.8 and 1.1%, respectively, for the (R)-(-)- and (S)-(+)-enantiomer in serum containing 15.4 mg/l (RS)-vigabatrin. The method was linear in the 0-45 mg/l range for both enantiomers and the minimum quantitation limit was 0.20 mg/l for (R)-(-)-vigabatrin and 0.14 mg/l for (S)-(+)-vigabatrin. No interferences were found from commonly co-administered antiepileptic drugs and from endogenous amino acids. The method is suitable for routine therapeutic drug monitoring and for pharmacokinetic studies.     

Sequence analysis of genes encoding rodent homologues of the human tumor-rejection antigen SART-1

OBJECTIVE: To assess pregnant women's knowledge of, and attitudes towards, antenatal HIV testing, and its acceptability to them. SETTING: Antenatal clinic at Guy's Hospital, London, six community antenatal clinics and a midwifery group practice. POPULATION: Eight hundred and forty-three women attending the antenatal clinics. METHOD: The women received a leaflet explaining HIV testing, and completed a questionnaire before and after their booking appointment. This included an assessment of their knowledge of, and attitudes towards HIV testing, and its acceptability. RESULTS: Seven hundred and eighty-nine women (94%) completed questionnaires. Fifty-one percent (n = 405) were Caucasian, 25% (n = 195) African, 11% (n = 86) West Indian and 13% (n = 100) were from other ethnic groups. Fifty-eight percent received the HIV information leaflet, of whom 86% had read it. Knowledge relating to HIV was good, the median knowledge score being 6 out of a possible 8, but it was less in non-Caucasian women and those with lower educational qualifications. Knowledge was not related to uptake of testing. Thirty-five percent of women accepted the offer of an HIV test, rates being higher in hospital clinics (41%) than in the midwifery group practice (10%) and the community clinics (30%). Women more likely to accept the offer of an HIV test were non-Caucasian (P = 0.0443), those who had thought about the HIV test before this pregnancy (P = 0.0298) and those seeing one particular midwife (P = 0.0003). Most women (67%) thought that all pregnant women should be offered the HIV test and then make their own decision. Overall, 64% women did not change their original pre-discussion decision on testing for HIV. Thirty-six percent of women changed their decision from 'yes' to 'no' or 'don't know' after seeing the midwife. Women attending the community clinics (P = 0.003) and those who had been tested before (P = 0.0451) were more likely to change their decision. CONCLUSION: This study, in a multiethnic population, has shown that knowledge regarding HIV is good but does not increase the uptake of testing. Women prefer to be offered the HIV test and make their own choice regarding whether to accept it.     

Developmental trends in visuospatial analysis and planning: I. Copying a complex figure.

An existing scoring system was used to assess the accuracy of the children's ability to copy the Rey-Osterrieth Complex Figure. The authors also developed additional measures to more precisely describe the process used by children in copying this figure. The findings suggest that children between the ages of 6 and 9 break the figure up into simple components but improve in their ability to integrate the figure with age. Younger children demonstrated a similar pattern of performance when copying the main features of the Rey-Osterrieth Complex Figure in isolation. The results of this study suggest that when faced with tasks requiring more advanced types of spatial analysis, children adopt strategies that proved successful when they were younger. Children have a variety of spatial analytic strategies available by age 6, but the strategy that they use is a function of pattern complexity and the capabilities of the child. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental trends in visuospatial analysis and planning: II. Memory for a complex figure.

The ability of children between the ages of 6 and 12 to draw the Rey-Osterrieth Complex Figure immediately after having copied the figure was assessed with an existing scoring system, as well as additional measures that the researchers developed to more precisely describe the process used by children in drawing this figure. As expected, younger children were poorer in their ability to recall the figure than older children. All children, regardless of age, were more likely to use continuous lines when drawing the main units of the figure from memory than when copying the figure. The approach used to analyze the figure when copying it from a model influenced the accuracy of the information recalled and the process by which it was recalled. That is, those children who broke the figure up into smaller units during copy were also more likely to recall the figure in a similar fashion and were more likely to recall less about the figure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental change in children's analysis of spatial patterns.

This study examines the early development of spatial pattern analysis and focuses on changes in the way that preschool children (3–5 yr olds) segment and integrate the parts of simple spatial forms. The results from each of the 3 experiments in this study show that young children analyze spatial patterns in ways that differ systematically from that of older children and adults. Changes with development were observed in the parts children segmented out of the forms and in the relations they used to organize the parts forming the overall pattern. The youngest children segmented out simple, well-formed, spatially independent parts and used simple relational structures to bind these parts together. With development, children constructed forms that included increasingly complex parts and relations. These findings were consistent across several different stimuli using 2 construction mediums. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New enzyme lineages by subdomain shuffling

Protein functions have evolved in part via domain recombination events. Such events, for example, recombine structurally independent functional domains and shuffle targeting, regulatory, and/or catalytic functions. Domain recombination, however, can generate new functions, as implied by the observation of catalytic sites at interfaces of distinct folding domains. If useful to an evolving organism, such initially rudimentary functions would likely acquire greater efficiency and diversity, whereas the initially distinct folding domains would likely develop into single functional domains. This represents the probable evolution of the S1 serine protease family, whose two homologous beta-barrel subdomains assemble to form the binding sites and the catalytic machinery. Among S1 family members, the contact interface and catalytic residues are highly conserved whereas surrounding surfaces are highly variable. This observation suggests a new strategy to engineer viable proteins with novel properties, by swapping folding subdomains chosen from among protein family members. Such hybrid proteins would retain properties conserved throughout the family, including folding stability as single domain proteins, while providing new surfaces amenable to directed evolution or engineering of specific new properties. We show here that recombining the N-terminal subdomain from coagulation factor X with the C-terminal subdomain from trypsin creates a potent enzyme (fXYa) with novel properties, in particular a broad substrate specificity. As shown by the 2.15-A crystal structure, plasticity at the hydrophobic subdomain interface maintains activity, while surface loops are displaced compared with the parent subdomains. fXYa thus represents a new serine proteinase lineage with hybrid fX, trypsin, and novel properties.     

Mutagenesis induced by bacterial UmuDC proteins and their plasmid homologues

The popular image of a world full of pollutants mutating DNA is only partly true since there are relatively few agents which can subtly and directly change base coding; for example, some alkylating agents alter guanine so that it pairs like adenine. Many more mutagens are less subtle and simply destroy coding altogether rather than changing it. Such mutagens include ultraviolet light, X-rays, DNA cross-linkers and other agents which make DNA breaks or large adducts. In Escherichia coli, mutagenesis by these agents occurs during a DNA repair process which increases cell survival but with an inherent possibility of changing the original sequence. Such mutagenic DNA repair is, in part, encoded by the E. coli umuDC operon. This article reviews the structure, function, regulation and evolution of the umuDC operon and similar genes found both in other species and on naturally occurring plasmids.     

Erythrocyte binding protein homologues of rodent malaria parasites

Evidence that ciliary neurotrophic factor promotes axonal sprouting and regeneration in the periphery raises the possibility that this factor is involved in reactive axonal growth in the brain. In situ hybridization was used in the present study to determine whether ciliary neurotrophic factor mRNA expression is increased in association with axonal sprouting in deafferented adult rat hippocampus. In untreated rats, ciliary neurotrophic factor cRNA labeling density was high in the olfactory nerve, pia mater, and aspects of the ventricular ependyma and was relatively low within areas of white matter (fimbria, internal capsule) and select neuronal fields (hippocampal cell layers, habenula). After an entorhinal cortex lesion, hybridization was markedly increased in fields of anterograde degeneration, including most prominently the ipsilateral dentate gyrus outer molecular layer and hippocampal stratum lacunosum moleculare. Labeling in these fields was increased by 3 days postlesion, was maximal at 5 days, and returned to normal levels by 14 days. Double labeling demonstrated that, in both control and experimental tissue, ciliary neurotrophic factor mRNA was colocalized with glial fibrillary acidic protein immunoreactivity in astroglia, but it was not colocalized with markers for oligodendrocytes or microglia. These results demonstrate that astroglial ciliary neurotrophic factor expression is increased in fields of axonal and terminal degeneration and that increased expression is coincident with 1) increased insulin-like growth factor-1 and basic fibroblast growth factor expression and 2) the onset of reactive axonal growth. The synchronous expression of these glial factors in fields of deafferentation suggests the possibility of additive or synergistic interactions in the coordination of central axonal growth.     

Developmental analysis of behavioral dysfunction in rats with septal lesions.

At 7 days of age, 48 male Long-Evans hooded rats received lesions of the septal nuclei or control operations. Ss then received 30 hrs of training on a DRL 20-sec schedule for 1 hr/day beginning at either 27 or 96 days of age. At 126 days of age, all Ss received 10 additional training sessions. After operant testing, all Ss received 10 additional training sessions. After operant testing, all Ss were tested on spontaneous alternation, spatial reversal, and passive avoidance. Results indicate that on a DRL 20-sec schedule Ss that received lesions of the septum neonatally and were tested at different ages performed in a similar manner. Approximately 50% of the Ss with lesions of the septal nuclei reached efficiency levels comparable with those of normal controls. When tested for retention, these efficient Ss still performed similarly to normal Ss. Ss with septal lesions were facilitated in the acquisition of a spatial habit, were deficient in spatial habit reversal, were less likely to demonstrate spontaneous alternation, and were deficient in passive avoidance. It is concluded that neonatal lesions of the septal nuclei produce permanent behavioral impairments on a diversity of measures and that, although juvenile animals with limbic system damage often manifest behaviors different from adult Ss, the difference is not evident during operant testing (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental analysis of the conditional reasoning abilities of primary-grade children.

Administered a conditional reasoning test to 36 1st-3rd graders. Each child was tested individually with a concrete and a verbal presentation of the test items. After his response to each test item, the child was asked to explain the reason for his response. An analysis of variance of the number of correct judgments showed significant main effects for Grade Level, Mode of Presentation, and Principle, and a significant Grade Level * Principle interaction. An examination of the explanations for correct judgments revealed that children's problem-solving behaviors varied according to both testing session and principle of inference. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental psychobiology and behaviour theory: Reciprocating influences.

Integrates aspects of infant development, psychobiology, and learning theory. Based on a large body of normative data, the author discusses levels of functioning in ontogeny, demonstrating the ages of first appearance in infancy of a number of reward-schedule effects. Levels of functioning in animals and humans are also examined, with reference to neuropsychological theories of memory function for humans. Findings from the author's work on the effects of hippocampal lesions and exposure to alcohol in utero on single alternation patterning and on the partial reinforcement extinction effect are also discussed. A modification of frustration theory is suggested, based on recent work relating differential hippocampal granule-cell genesis to exposure to a number of reward-schedule effects in infancy. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental analysis of the role of social comparison in self-evaluation.

The use of social comparison information for self-evaluation may be viewed as a major developmental step in children's growing understanding of their competencies and limitations. The 2 studies presented here suggested that children's achievement-related self-evaluations are little affected by relative comparisons until surprisingly late—that is, not earlier than 7–8 yrs of age. In Study 1, 104 1st and 2nd graders performed a task with 3 coacting peers; only the 2nd graders made any use at all of the social comparison information in their evaluative judgments. In Study 2 an attempt was made to maximize the potential for using comparative information by providing a strong incentive to engage in social comparsion of abilities in a situation in which objective information about a success/failure outcome was unavailable. The 90 kindergarten, 2nd, and 4th graders played a game with peers and made competence-related self-evaluations and decisions about future performance. Only the judgments of the 4th graders were consistently affected by the social comparison information. Previous research on the development of social comparison and possible explanations for the developmental trends observed are discussed. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Racial and ethnic identity: Developmental perspectives and research.

Developmental research is reviewed to evaluate how race, ethnicity, racial identity, and ethnic identity are defined and investigated for minority populations. First reviewed is how these terms are used in developmental and counseling research. Early practices limited these terms to their demographic denotations (e.g., heritage), but more recent practices have expanded to include socially constructed connotations. Second, developmental research was used to evaluate key assumptions in theories of racial and ethnic identity development, with an emphasis on recent longitudinal studies. Research supports some, but not all, of these developmental predictions. Longitudinal research supported the progressive nature of ethnic and racial identity development and that exposure to racism appears to stimulate further identity development during adolescence. In contrast, available evidence does not support the claims of a developmental hierarchy for racial ideologies and that identity crises are normative. Adjustment was not predicted by a single racial or ethnic identity ideology, but research suggested that the adolescent's sociocultural identity and socialization should be tailored to the nature of the racial and ethnic context for development. Implications for counseling research and practice are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental Psychology and Public Policy: Progress and Prospects.

This article outlines a framework for developmentally oriented policy research. Drawing from U. Bronfenbrenner's (1995) dynamic developmental systems theory, the authors suggest ways in which the key tenets of process, persons, context, and time can inform policy research in developmental psychology and can be used to support a causal interpretation of the results of those analyses. Conceptualizing public policies from a dynamic developmental systems perspective has a variety of implications for future research, and this article considers some of these implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early neuropsychological dysfunctions in workers exposed to benzene and its homologues

Empiric therapy is practical and must be begun promptly; the specific regimen chosen must be based upon local conditions and epidemiology. It must be recalled that subgroups of patients are not necessarily equivalent to the majority, i.e., there are low-risk patients for whom ambulatory and/or oral therapy is appropriate and, conversely, there are high-risk patients who have a potential for a high mortality and who, while perhaps few in number, are of critical importance. Further, many of these patients are very complex, and this leads to a high level of physician concern and insecurity. This physician concern, in turn, leads to a tendency to modify regimens, given that the physician all too often is dealing with inadequate diagnostic information owing to the patient situation. The physician's choice of modification is highly dependent upon knowledge of the regimen the patient is already receiving. There is a need for clear definition of endpoints, and these must be established before the study is initiated. All too many published studies are too small to evaluate the endpoint that has been defined, and many others, although sufficient in size, have all of the problems inherent in studies conducted at multiple sites by multiple individuals with differing degrees of commitment or enthusiasm toward the study at hand. A few implications for study design and evaluation seem evident: it is critical to define endpoints and execute the study accordingly. This means determining the size of the population needed and determining the presence or absence of risk groups. Patients to be excluded e.g., those in whom infection is doubted must be selected on the basis of objective data by an observer blinded to both the outcome and the treatment. Similarly, the classification of response should preferably be done by an observer not influenced by knowledge of the therapy being given. Finally, and similarly, the decision to modify therapy (especially if modification is equivalent to defining failure with the regimen) should not be influenced by knowledge of the therapy being administered.