Single mothers' perceptions of neighborhood social cohesion, parenting stress, adverse childhood experiences in early childhood and Black children's behavior problems in middle childhood and adolescence

This study examined the roles of neighborhood social cohesion, adverse childhood experiences (ACEs), and parenting stress in early childhood on child behavioral outcomes in middle childhood and adolescence among socioeconomically disadvantaged Black families. To test a model linking perceptions of neighborhood social cohesion, single mothers' parenting stress, ACEs, and behavior problems in middle childhood and adolescence. We used four waves of longitudinal data from a subsample of 800 unmarried Black mothers and their children (at child birth and ages 3, 5, 9, and 15) from the Future of Families and Child Wellbeing Study, a nationally representative data set. Structural equation modeling with latent variables was used to measure direct and indirect effects. Mothers' perceptions of neighborhood social cohesion were significantly and negatively associated parenting stress (β = -0.34, p < 0.05); parenting stress was significantly and positively related to adverse childhood experiences (β = 0.40, p < 0.05) and behavior problems (β = 0.32, p < 0.05); Adverse childhood experiences were significantly and positively related to behavior problems (β = 0.26, p < 0.05); and behavior problems were indirectly influenced by neighborhood social cohesion through adverse childhood experiences (β = -0.14, p < 0.05) and parenting stress (β = 0.10, p < 0.05). Neighborhood factors may play a significant role in parenting stress, adverse childhood experiences in early childhood, and children's behavior problems in middle childhood and adolescence among some single mothers and children in economically and socially disadvantaged Black families. Interventions that enhance neighborhood social cohesion and foster supportive interactions among community members and organizations are recommended.

Depression and HIV risks: Engaging older African American women in HIV prevention education through the church

This report describes the recruitment of a sample of older African American women to test the effectiveness of an educational HIV prevention intervention that sought to reduce depressive symptoms and thereby HIV risks in this population. The outreach venue is the Black church. A framework for maximizing response is suggested. Of 62 women who participated in two arms of the intervention, 29 were assigned randomly to a four-session discussion group (experimental condition) and 33 were assigned to a one-session informational group (control condition) focused on HIV prevention education. Between-within subjects analyses of variance showed that participation in the study was associated with a significant improvement in the women's psychological status, i.e., decreased depressive symptoms. This change in depressive symptoms was due in part to the experimental condition assignment. Implications for future HIV prevention interventions, research, and methods used to maximize the probability of response among older African American women are discussed.

Adverse childhood experiences and behavior problems among poor Black children: Nonresident father involvement and single mothers' parenting stress

BACKGROUND

Adverse childhood experiences (ACEs) in early childhood and developmental outcomes during the middle childhood and adolescent years have been understudied among low-income Black families.

OBJECTIVE

To test a model linking economic hardship, single mothers' parenting stress, ACEs, and nonresident fathers' involvement in early childhood to behavior problems in middle childhood and adolescence.

PARTICIPANTS AND SETTING

We used six waves of longitudinal data from a subsample of 800 unmarried Black mothers, nonresident fathers, and their children (at child birth and ages 1, 3, 5, 9, and 15) from the Fragile Families and Child Wellbeing Study, a nationally representative data set.

METHOD

Structural equation models with latent variables that incorporate path analysis and confirmatory factor analysis were tested.

RESULTS

Mothers' economic hardship was associated directly with parenting stress (beta = 0.27, p < .001) and related both directly (beta = 0.22, p < .001) and indirectly (through parenting stress) to the children's increased likelihood of exposure to ACEs (indirect effect = 0.05, p < .001). Nonresident fathers' involvement early on (child's age 1 to 5) was associated directly with reductions in the mothers' economic hardship (beta = -0.18, p < .001), children's reduced exposure to ACEs (beta = -0.15, p < .001), and fewer behavior problems in middle childhood and adolescence (beta = -0.10, p < .001).

CONCLUSION

Nonresident Black fathers' involvement in single-mother families may buffer the adverse consequences over time for economically and socially disadvantaged Black children of exposure to ACEs in early childhood. Interventions that encourage sustained involvement by nonresident Black fathers with young children and their single mothers are recommended.

HIV Prevention Programming for Older African American Women: The Impact of a Faith-Based and Behavioral Science Partnership on Depressive Symptoms

Objective

The current study sought to test the effect of an HIV prevention intervention on depressive symptoms in a sample of older African American women.

Design Setting and Participants

A pretest-posttest randomized control group design was conducted in a mega-church in Los Angeles with a sample of 62 older African American women, aged ≥50 years, 29 of whom were randomly assigned to the experimental condition and 33 to the comparison/control condition.

Measures

A measure of psychological wellbeing (CES-D) was utilized to test the effect of the four-session group intervention vs the one-session informational group intervention on change in depressive symptoms from pretest to posttest. Demographic characteristics included: measures of age in years; relationship and employment statuses (coded 1 for yes, 0 for no); and educational attainment.

Results

Participation in the study was associated with a significant improvement in the women's psychological wellbeing from baseline to time 2; ie, decreased depressive symptoms. This change was greater for women in the four-session experimental group than for those in the one-session comparison group, due in part to a marginally significant interaction between time and experimental conditions.

Conclusions

This study demonstrates the utility of faith-based/behavioral-scientist partnerships in HIV programming. Findings contribute to the evidence on interventions that might reduce depressive symptoms and HIV risk among older African American women.

Adverse experiences in early childhood and their longitudinal impact on later behavioral problems of children living in poverty

BACKGROUND

Adverse childhood experiences (ACEs) are an identified risk factor for the social and emotional development of children. What is less known is the long-term effects of ACEs when poverty and ACEs coincide.

OBJECTIVE

Using longitudinal cohort-panel data, we examined whether exposure to ACEs by the age of three among poor children would longitudinally result in behavioral problems at ages three, five, nine, and 15, after controlling for mothers' socioeconomic status and their children's characteristics.

PARTICIPANTS AND SETTING

We used a subsample of 2750 children and their parents living in urban poverty from the Fragile Families and Child Wellbeing study.

METHODS

Logistic regression modeling was used to obtain adjusted odds ratios of ACE categories predicting behavioral problems after accounting for family socioeconomic position.

RESULTS

Our findings indicate that experiencing ACEs in early childhood was significantly associated with later behavioral outcomes from childhood to adolescence. Exposure to multiple ACEs before the age of three was significantly associated with the top-risk behavior group at age five; the odd ratios were 2.0 (CI = 1.3-3.1) and 2.9 (CI = 1.8-4.6) for two ACEs and three or more ACEs, respectively. At both ages nine and 15, children experiencing two or more ACEs had 1.9 to 3.2 times higher odds to demonstrate more the top 10th percentile of behavioral problems. Among covariates, mothers' race and education, and children's gender and temperament were identified as significant factors to determine behavior problems.

CONCLUSIONS

The findings support policies and programs for families with children who have experienced economic disadvantages and early childhood adversity.

Acute effects of exercise on appetite, ad libitum energy intake and appetite-regulatory hormones in lean and overweight/obese men and women

BACKGROUND

Acute exercise does not elicit compensatory changes in appetite parameters in lean individuals; however, less is known about responses in overweight individuals. This study compared the acute effects of moderate-intensity exercise on appetite, energy intake and appetite-regulatory hormones in lean and overweight/obese individuals.

METHODS

Forty-seven healthy lean (n=22, 11 females; mean (s.d.) 37.5 (15.2) years; 22.4 (1.5) kg m^-2) and overweight/obese (n=25, 11 females; 45.0 (12.4) years, 29.2 (2.9) kg m^-2) individuals completed two, 8 h trials (exercise and control). In the exercise trial, participants completed 60 min treadmill exercise (59 (4)% peak oxygen uptake) at 0-1 h and rested thereafter while participants rested throughout the control trial. Appetite ratings and concentrations of acylated ghrelin, peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were measured at predetermined intervals. Standardised meals were consumed at 1.5 and 4 h and an ad libitum buffet meal was provided at 7 h.

RESULTS

Exercise suppressed appetite (95% confidence interval (CI) -3.1 to -0.5 mm, P=0.01), and elevated delta PYY (95% CI 10 to 17 pg ml^-1, P<0.001) and GLP-1 (95% CI 7 to 10 pmol l^-1, P<0.001) concentrations. Delta acylated ghrelin concentrations (95% CI -5 to 3 pg ml^-1, P=0.76) and ad libitum energy intake (95% CI -391 to 346 kJ, P=0.90) were similar between trials. Subjective and hormonal appetite parameters and ad libitum energy intake were similar between lean and overweight/obese individuals (P⩾0.27). The exercise-induced elevation in delta GLP-1 was greater in overweight/obese individuals (trial-by-group interaction P=0.01), whereas lean individuals exhibited a greater exercise-induced increase in delta PYY (trial-by-group interaction P<0.001).

CONCLUSIONS

Acute moderate-intensity exercise transiently suppressed appetite and increased PYY and GLP-1 in the hours after exercise without stimulating compensatory changes in appetite in lean or overweight/obese individuals. These findings underscore the ability of exercise to induce a short-term energy deficit without any compensatory effects on appetite regardless of weight status.

The Effects of Collaborative Care Training on Case Managers' Perceived Depression-Related Services Delivery

OBJECTIVE

This study examined the effects of a depression care quality improvement (QI) intervention implemented by using Community Engagement and Planning (CEP), which supports collaboration across health and community-based agencies, or Resources for Services (RS), which provides technical assistance, on training participation and service delivery by primarily unlicensed, racially and ethnically diverse case managers in two low-income communities in Los Angeles.

METHODS

The study was a cluster-randomized trial with program-level assignment to CEP or RS for implementation of a QI initiative for providing training for depression care. Staff with patient contact in 84 health and community-based programs that were eligible for the provider outcomes substudy were invited to participate in training and to complete baseline and one-year follow-up surveys; 117 case managers (N=59, RS; N=58, CEP) from 52 programs completed follow-up. Primary outcomes were time spent providing services in community settings and use of depression case management and problem-solving practices. Secondary outcomes were depression knowledge and attitudes and perceived system barriers.

RESULTS

CEP case managers had greater participation in depression training, spent more time providing services in community settings, and used more problem-solving therapeutic approaches compared with RS case managers (p<.05).

CONCLUSIONS

Training participation, time spent providing services in community settings, and use of problem-solving skills among primarily unlicensed, racially and ethnically diverse case managers were greater in programs that used CEP rather than RS to implement depression care QI, suggesting that CEP offers a model for including case managers in communitywide depression care improvement efforts.

The effect of prone positioning with surgical bolsters on liver blood flow in healthy volunteers

This study sought to identify changes in hepatic flood flow and cardiac output during prone positioning on surgical bolsters in awake volunteers, and was prompted by a local incident of significant hepatic dysfunction following surgery in the prone position. Cardiac output was determined using the non-invasive Peñáz technique, and plasma disappearance rate of indocyanine green (ICG-PDR) was measured as a surrogate maker for hepatic blood flow along with serum hepatic enzyme assays. Measurements were made after one hour in supine, prone and returned supine positions. Ten volunteers completed the study. There were significant changes in the disappearance rate of indocyanine green, which decreased this from mean (SD) 31.1 (9.70) supine to 19.6 (4.37)%.min prone, respectively (p = 0.02), increasing on return to the supine position to 24.6 (5.54)%.min (p = 0.019). Cardiac output was also significantly reduced when changing from the supine to the prone position, from mean (SD) 4.7 (1.0 to 3.5 (1.1) (l.min(-1) ), respectively (p = 0.002). We demonstrated an acute and reversible change in both hepatocellular function and cardiac output associated with the prone position.

Proximal and Distal Predictors of AIDS Risk Behaviors among Inner-city African American and European American Women

AIDS risk behavior and attitudes towards safer sex were studied in a sample of 666 African American and 626 European American women. Condom use, AIDS-related knowledge, risk perception, self-efficacy beliefs, attitudes and perceived partner attitudes, and an assertive coping style were analyzed with regard to mean differences and predictive power in both ethnic groups. Compared to European American women, African American women had less knowledge and lower self-efficacy beliefs towards safer sex behavior, but they perceived themselves to be at more risk and reported greater condom use. Further, ethnicity was found to moderate the effects of the psychological predictors on safer sex behavior. This moderator effect was tested using a structural equation modeling design. In both groups, risk perception was the strongest predictor of condom use. Among African American women, social-cognitive barriers (e.g. low self-efficacy beliefs, negative attitude towards condom use) worked as a second predictor and mediator of the effects of risk perception on condom use. In contrast, among European American women, social-cognitive factors had no effect on condom use. In general, prediction of safer sex behavior was stronger among African American women.

Single Parenting and Child Behavior Problems in Kindergarten

Two waves of data from a sample of 89 poor and near-poor single black mothers and their preschool children were used to study the influences of parenting stress, physical discipline practices, and nonresident fathers' relations with their children on behavior problems in kindergarten. The results indicate that higher levels of parent stress, more frequent spanking, and less frequent father-child contact at time 1 were associated with increased teacher-reported behavior problems at time 2. In addition, more frequent contact between nonresident biological fathers and their children moderated the negative effect of harsh discipline by mothers on subsequent child behavior problems. Specifically, when contact with the father was low, maternal spanking resulted in elevated levels of behavior problems; with average contact, this negative effect of spanking was muted; and with high contact, spanking was not associated with increased behavior problems in kindergarten. The implications of these findings for future research and policy are discussed.

Scn3b knockout mice exhibit abnormal sino-atrial and cardiac conduction properties

Aim

In contrast to extensive reports on the roles of Na_v1.5 α-subunits, there have been few studies associating the β-subunits with cardiac arrhythmogenesis. We investigated the sino-atrial and conduction properties in the hearts of Scn3b^−/− mice.

Methods

The following properties were compared in the hearts of wild-type (WT) and Scn3b^−/− mice: (1) mRNA expression levels of Scn3b, Scn1b and Scn5a in atrial tissue. (2) Expression of the β₃ protein in isolated cardiac myocytes. (3) Electrocardiographic recordings in intact anaesthetized preparations. (4) Bipolar electrogram recordings from the atria of spontaneously beating and electrically stimulated Langendorff-perfused hearts.

Results

Scn3b mRNA was expressed in the atria of WT but not Scn3b^−/− hearts. This was in contrast to similar expression levels of Scn1b and Scn5a mRNA. Immunofluorescence experiments confirmed that the β₃ protein was expressed in WT and absent in Scn3b^−/− cardiac myocytes. Lead I electrocardiograms from Scn3b^−/− mice showed slower heart rates, longer P wave durations and prolonged PR intervals than WT hearts. Spontaneously beating Langendorff-perfused Scn3b^−/− hearts demonstrated both abnormal atrial electrophysiological properties and evidence of partial or complete dissociation of atrial and ventricular activity. Atrial burst pacing protocols induced atrial tachycardia and fibrillation in all Scn3b^−/− but hardly any WT hearts. Scn3b^−/− hearts also demonstrated significantly longer sinus node recovery times than WT hearts.

Conclusion

These findings demonstrate, for the first time, that a deficiency in Scn3b results in significant atrial electrophysiological and intracardiac conduction abnormalities, complementing the changes in ventricular electrophysiology reported on an earlier occasion.

Contribution of calcium-containing crystals to cartilage degradation and synovial inflammation in osteoarthritis

OBJECTIVES

The role of calcium phosphate and pyrophosphate crystals in osteoarthritis (OA) is unclear: are they a symptom of the damage that occurs to the joint or a key intermediate in the progression of inflammation and joint damage that occurs in OA? The proinflammatory and catabolic response of synthetic calcium phosphate and pyrophosphate crystals and crystals extracted from human osteoarthritic knee cartilage has been investigated. The crystal forms eliciting a response have been characterised allowing a comparison of the biological effects of synthetic and native calcium crystals on human osteoarthritic chondrocytes and synoviocytes to be carried out.

METHODS

Calcium phosphate and pyrophosphate crystals were synthesised in vitro and their crystal forms characterised by X-ray powder diffraction (XRPD). The inorganic crystalline material present in human osteoarthritic cartilage was extracted and its structural composition elucidated by XRPD. These crystals were applied to human primary osteoarthritic chondrocytes and synoviocytes and the production of proinflammatory and catabolic mediators measured.

RESULTS

The crystals extracted from human osteoarthritic knee cartilage were identified as consisting of a mixture of monoclinic and triclinic calcium pyrophosphate dihydrate (m-CPPD and t-CPPD). These crystals elicited an inflammatory and catabolic response in human primary osteoarthritic chondrocytes and synoviocytes as measured by an increase in nitric oxide (NO), matrix metalloproteinase 13 (MMP-13) and prostaglandin E2 (PGE(2)) production. NO, MMP-13 and PGE(2) production was also increased when the synthetic calcium hydrogen phosphate dihydrate (DCPD) and calcium pyrophosphate hydrates were applied to the cells.

CONCLUSIONS

Crystals extracted from human osteoarthritic knee cartilage induce the production of proinflammatory and catabolic mediators (NO, MMP-13 and PGE(2)) in human primary chondrocytes and synoviocytes. Synthetic calcium phosphate and pyrophosphate crystals elicit a similar response in those cells. Our findings suggest that these crystals could contribute to cartilage degradation and synovitis in OA.

Parenting Efficacy and the Early School Adjustment of Poor and Near-Poor Black Children

This short-term longitudinal study investigated whether maternal educational attainment, maternal employment status, and family income affect African-American children's behavioral and cognitive functioning over time through their impacts on mothers' psychological functioning and parenting efficacy in a sample of 100 poor and near-poor single black mothers and their 3- and 4-year-old focal children. Results indicate that education, working status, and earnings display statistically significant, negative, indirect relations with behavior problems and, with the exception of earnings, statistically significant, positive, indirect relationships with teacher-rated adaptive language skills over time. Findings suggest further that parenting efficacy may mediate the link between poor and near-poor single black mothers' depressive symptoms and their preschoolers' subsequent school adjustment. Implications of these findings for policy and program interventions are discussed.

The genome of the simian and human malaria parasite Plasmodium knowlesi

Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to Plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or 'hypnozoite' in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome and other sequenced Plasmodium genomes. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.

Low-wage maternal employment and parenting style

This three-year longitudinal study investigated whether low-wage employment was associated with improved psychological and parenting outcomes in a sample of 178 single mothers who were employed and unemployed current and former welfare recipients both before and subsequent to the passage of the Personal Responsibility and Work Opportunity Reconciliation Act of 1996. Participation in employment predicted fewer depressive symptoms and less negative parenting style over time. Employment at time 1 was associated with a reduced likelihood of receiving welfare in the interim between times 1 and 2, less financial strain at time 2, and (through these) a decrease in mothers' depressive symptoms at time 2. Fewer depressive symptoms at time 2, in turn, predicted less negative parenting style, net of the mothers' earlier demographic, mental health, and parenting characteristics. Mothers with higher education attainment were more likely to be employed (and to earn more) at both time points. Implications of these findings for welfare policies are discussed.

Comparative study of the efficacy of eprinomectin versus ivermectin, and field efficacy of eprinomectin only, for the treatment of chorioptic mange in alpacas

The efficacy of eprinomectin versus ivermectin (Study 1: a single-centre, randomised, treatment-controlled, blinded field trial), and the field efficacy of eprinomectin (Study 2: a single-centre, open, un-controlled field trial) for the treatment of chorioptic infestation in naturally infested alpacas were assessed in two studies. Thirty alpacas, all positive for Chorioptes sp. mite, were randomly allocated to two treatment groups in Study 1. Group A received a single topical administration of a 0.5% formulation of eprinomectin at the dose rate of 500mug/kg. Group B received three subcutaneous administrations at 14 days interval of a 1% formulation of ivermectin at the dose rate of 400mug/kg. Response to treatment was assessed by periodic mite count, and skin lesions scored. In Study 2, one group of 19 alpacas received four administrations at weekly interval of topical eprinomectin at the dose rate of 500mug/kg, and response to treatment was monitored by mite counts. No localised or systemic side effects were observed in either trial. There was a statistically significant decrease in mite counts on day 7 (P<0.001) within treatment Groups A and B of Study 1, but mite counts increased again on day 14 and remained high for the duration of the trial in both treatment groups. On day 14 of Study 2, there was a statistically significant reduction in mite counts (P<0.008) and the mite counts remained very low throughout the remainder of the study. The eprinomectin protocol employed in Study 2, consisting of four weekly topical administrations at the dose rate of 500mug/kg of body weight, proved highly effective at reducing the Chorioptes mite burden in alpacas.

A second locus for Aicardi-Goutieres syndrome at chromosome 13q14-21

BACKGROUND

Aicardi-Goutières syndrome (AGS) is an autosomal recessive, early onset encephalopathy characterised by calcification of the basal ganglia, chronic cerebrospinal fluid lymphocytosis, and negative serological investigations for common prenatal infections. AGS may result from a perturbation of interferon alpha metabolism. The disorder is genetically heterogeneous with approximately 50% of families mapping to the first known locus at 3p21 (AGS1).

METHODS

A genome-wide scan was performed in 10 families with a clinical diagnosis of AGS in whom linkage to AGS1 had been excluded. Higher density genotyping in regions of interest was also undertaken using the 10 mapping pedigrees and seven additional AGS families.

RESULTS

Our results demonstrate significant linkage to a second AGS locus (AGS2) at chromosome 13q14-21 with a maximum multipoint heterogeneity logarithm of the odds (LOD) score of 5.75 at D13S768. The AGS2 locus lies within a 4.7 cM region as defined by a 1 LOD-unit support interval.

CONCLUSIONS

We have identified a second AGS disease locus and at least one further locus. As in a number of other conditions, genetic heterogeneity represents a significant obstacle to gene identification in AGS. The localisation of AGS2 represents an important step in this process.

Replication of cranial gunshot wounds

It is possible to differentiate between entrance and exit wounds in bone by examining the specimen concerned. Because of the evidential usefulness of providing jurists or members of a jury with such specimens, we describe an easy and reliable method for replicating gunshot wounds in the human skull utilizing dental materials and methods.

The effects of family and neighborhood characteristics on the behavioral and cognitive development of poor Black children: a longitudinal study

Using data from an ongoing study of 178 single-mother, Black families, this study investigates the relations among family resources (mothers' employment, income from employment, and educational attainment), maternal depressive symptoms, neighborhood quality in the preschool years and over time, and child developmental outcomes (behavior problems, broad reading, calculation) in the early school years. Results indicate that behavior problems in school-age children were associated with behavior problems early on, the child's gender, the mother's depressive symptoms and, to some extent, her employment status. However, these findings were conditioned by the mother's educational attainment and her evaluation of neighborhood problems early on. Better broad reading scores were associated with higher maternal educational attainment, especially for school-age girls of employed mothers, whereas higher calculation scores were predicted by fewer school-age behavior problems and, in the presence of higher neighborhood problems in the preschool years, mothers' higher educational attainment.

An autosomal recessive exfoliative ichthyosis with linkage to chromosome 12q13

A new variant of congenital exfoliative ichthyosis in two related Bedouin families is reported. The ichthyosis appeared shortly after birth as a fine peeling of nonerythematous skin on the palms and soles. The prominent well-demarcated areas of denuded skin in moist and traumatized regions resembled the 'mauserung' phenomenon of ichthyosis bullosa of Siemens (IBS). Unlike in IBS, epidermolysis is absent on histological examination. Electron microscopy revealed a prominent intercellular oedema and numerous aggregates of keratin filaments in basal keratinocytes. Abnormal keratin (K) 1 expression was seen in the affected epidermis; however, all other keratins, including K2e, had a distribution comparable to that seen in normal controls. A maximum two-point LOD score of 2.53 and multipoint LOD score of 3.76 were obtained for marker D12S390, suggesting linkage to the type II keratin cluster on chromosome 12q13. Sequencing of both the K1 gene, the promotor and the 3' calcium regulatory region did not reveal a mutation. K2e and K5 genes, as well as the genes harboured within the minimal region, such as retinoic acid receptor gamma, sterol O-acyltransferase 2, integrin beta7 and insulin-like growth factor binding protein-6, were also excluded. This combination of clinical, histological, ultrastructural and genetic features has not been previously reported in other congenital exfoliative ichthyoses. We therefore suggest that it represents a new form of exfoliative ichthyosis.

Analysis of differential gene expression supports a role for amyloid precursor protein and a protein kinase C substrate (MARCKS) in long-term memory

Previous work has identified the intermediate and medial part of the hyperstriatum ventrale (IMHV) as a region of the chick brain storing information acquired through the learning process of imprinting. We have examined in this brain region changes in expression of candidate genes involved in memory. Chicks were exposed to a rotating red box and the strength of their preference for it, a measure of learning, determined. Brain samples were removed approximately 24 h after training. Candidate genes whose expressions were different in IMHV samples derived from strongly imprinted chicks relative to those from chicks showing little or no learning were identified using subtractive hybridization. The translation products of two candidate genes were investigated further in samples from the left and right IMHV and from two other brain regions not previously implicated in imprinting, the left and right posterior neostriatum. One of the proteins was the amyloid precursor protein (APP), the other was myristoylated alanine rich C kinase substrate (MARCKS). In the left IMHV the levels of the two proteins increased with the strength of learning. The effects in the right IMHV were not significantly different from those in the left. There were no effects of learning in the posterior neostriatum. This is the first study to relate changes in the amounts of MARCKS and APP proteins to the strength of learning in a brain region known to be a memory store and demonstrates that the systematic identification of protein molecules involved in memory formation is possible.

Cree encephalitis is allelic with Aicardi-Goutiéres syndrome: implications for the pathogenesis of disorders of interferon alpha metabolism

Aicardi-Goutiéres syndrome (AGS) is an early onset, progressive encephalopathy characterised by calcification of the basal ganglia, white matter abnormalities, and a chronic cerebrospinal fluid (CSF) lymphocytosis. Cree encephalitis shows phenotypic overlap with AGS although the conditions have been considered distinct because of immunological abnormalities observed in Cree encephalitis. We report that levels of interferon alpha (IFN-alpha), a marker of AGS, are raised in Cree encephalitis. Moreover, linkage analysis indicates that the disorders are allelic and refines the AGS1 locus to a 3.47 cM critical interval. Our data show that a CSF lymphocytosis is not necessary for the diagnosis of AGS and strongly suggest that AGS and pseudo-TORCH syndrome are the same disorder. Recognition of immunological dysfunction as part of the AGS phenotype provides further evidence of a primary pathogenic role for abnormal IFN-alpha production in AGS.

The sodium channel beta-subunit SCN3b modulates the kinetics of SCN5a and is expressed heterogeneously in sheep heart

1. Cardiac sodium channels are composed of a pore-forming alpha-subunit, SCN5a, and one or more auxiliary beta-subunits. The aim of this study was to investigate the role of the recently discovered member of the beta-subunit family, SCN3b, in the heart. 2. Northern blot and Western blot studies show that SCN3b is highly expressed in the ventricles and Purkinje fibres but not in atrial tissue. This is in contrast to the uniform expression of SCN1b throughout the heart. 3. Co-expression of SCN3b with the cardiac-specific alpha-subunit SCN5a in Xenopus oocytes resulted in a threefold increase in the level of functional sodium channel expression, similar to that observed when SCN1b was co-expressed with SCN5a. These results suggest that both SCN1b and SCN3b improve the efficiency with which the mature channel is targeted to the plasma membrane. 4. When measured in cell-attached oocyte macropatches, SCN3b caused a significant depolarising shift in the half-voltage of steady-state inactivation compared to SCN5a alone or SCN5a + SCN1b. The half-voltage of steady-state activation was not significantly different between SCN5a alone and SCN5a + SCN3b or SCN5a + SCN1b. 5. The rates of inactivation for SCN5a co-expressed with either subunit were not significantly different from that for SCN5a alone. However, recovery from inactivation at -90 mV was significantly faster for SCN5a + SCN1b compared to SCN5a + SCN3b, and both were significantly faster than SCN5a alone. 6. Thus, SCN1b and SCN3b have distinctive effects on the kinetics of activation and inactivation, which, in combination with the different patterns of expression of SCN3b and SCN1b, could have important consequences for the integrated electrical activity of the intact heart.

Amphiphysin is necessary for organization of the excitation-contraction coupling machinery of muscles, but not for synaptic vesicle endocytosis in Drosophila

Amphiphysins 1 and 2 are enriched in the mammalian brain and are proposed to recruit dynamin to sites of endocytosis. Shorter amphiphysin 2 splice variants are also found ubiquitously, with an enrichment in skeletal muscle. At the Drosophila larval neuromuscular junction, amphiphysin is localized postsynaptically and amphiphysin mutants have no major defects in neurotransmission; they are also viable, but flightless. Like mammalian amphiphysin 2 in muscles, Drosophila amphiphysin does not bind clathrin, but can tubulate lipids and is localized on T-tubules. Amphiphysin mutants have a novel phenotype, a severely disorganized T-tubule/sarcoplasmic reticulum system. We therefore propose that muscle amphiphysin is not involved in clathrin-mediated endocytosis, but in the structural organization of the membrane-bound compartments of the excitation-contraction coupling machinery of muscles.

Associations between employment and financial and parental stress in low-income single black mothers

Using a sample of 188 low-income single black mothers (93 employed and 95 nonemployed), this study investigated financial strain, maternal depressive affect, and parenting stress among former welfare recipients who are now working, and current welfare recipients who are not employed. The findings suggested that being employed did not reduce financial strain, as the two groups reported similar levels of strain. However, regression analyses indicated that not being employed was associated with reporting higher levels of stress. Parenting stress was also associated with attaining less education, having boys, reporting more financial strain and depressive affect. Correlates of maternal depressive affect were mother's education and financial strain. Interaction effects were found for employment by financial strain, indicating that higher levels of depressive affect were related to more financial strain among nonemployed mothers. The findings suggest that although employment is associated with better mental health for poor mothers, entry into the workforce is associated with stronger links between financial strain, parenting stress and depressive affect for mothers leaving welfare.

Mutation in the gene encoding ferritin light polypeptide causes dominant adult-onset basal ganglia disease

We describe here a previously unknown, dominantly inherited, late-onset basal ganglia disease, variably presenting with extrapyramidal features similar to those of Huntington's disease (HD) or parkinsonism. We mapped the disorder, by linkage analysis, to 19q13.3, which contains the gene for ferritin light polypeptide (FTL). We found an adenine insertion at position 460-461 that is predicted to alter carboxy-terminal residues of the gene product. Brain histochemistry disclosed abnormal aggregates of ferritin and iron. Low serum ferritin levels also characterized patients. Ferritin, the main iron storage protein, is composed of 24 subunits of two types (heavy, H and light, L) which form a soluble, hollow sphere. Brain iron deposition increases normally with age, especially in the basal ganglia, and is a suspected causative factor in several neurodegenerative diseases in which it correlates with visible pathology, possibly by its involvement in toxic free-radical reactions. We found the same mutation in five apparently unrelated subjects with similar extrapyramidal symptoms. An abnormality in ferritin strongly indicates a primary function for iron in the pathogenesis of this new disease, for which we propose the name 'neuroferritinopathy'.

A fifth locus for primary autosomal recessive microcephaly maps to chromosome 1q31

Primary microcephaly is a genetic disorder in which an affected individual has a head circumference >3 SDs below the age- and sex-related mean. A small but apparently normally formed brain is the reason for the reduced head circumference, and, probably because of this, all affected individuals are mentally retarded. The condition is genetically heterogeneous, and four loci have already been identified. We now report a fifth locus, MCPH5, which is an 8-cM region mapping to chromosome 1q31, defined by the markers GATA135F02 and D1S1678.

A new locus for autosomal recessive non-syndromal sensorineural hearing impairment (DFNB27) on chromosome 2q23-q31

Non-syndromic sensorineural deafness is an extremely genetically heterogeneous condition. We have used autozygosity mapping in a large consanguineous United Arab Emirate family to identify a novel locus for autosomal recessive non-syndromic sensorineural deafness, DFNB27, on chromosome 2q23-q31, with a maximum two-point lod score of 5.18 at theta = 0 for marker D2S2257. The DFNB27 locus extends over a 17 cM region between D2S2157 and D2S2273, and may overlap the DFNA16 locus for dominantly inherited, fluctuating, progressive non-syndromal hearing loss. However, genotype data suggests that the locus is likely to be refined to between D2S326 and D2S2273 and thus distinct from the DFNA16 locus.

Learning fibreoptic endoscopy. Nasotracheal or orotracheal intubations first?

We have studied the extent to which learning fibreoptic nasotracheal endoscopy first helped anaesthetists to learn fibreoptic orotracheal endoscopy later, and vice versa. After preliminary training on a bronchial tree model, 30 anaesthetic trainees were randomly allocated to the nasal first/oral second group, who performed 10 nasal intubations followed by 10 oral intubations, or the oral first/nasal second group, who performed 10 oral intubations followed by 10 nasal intubations, in anaesthetised, ASA group I or II patients undergoing elective oral or general surgery. Each type of endoscopy was taught in a standard manner, with the aid of an endoscopic video-camera system, under the supervision of experienced instructors. Performing nasal endoscopy second (average 70.8 s) took significantly less time than performing it first (average 84.4 s) and performing oral endoscopy second (average 35.2 s) took significantly less time than performing it first (average 48.5 s). The mean (SD) total endoscopy time for all the endoscopies (both nasal and oral) in the nasal first/oral second group [1196 (162) s] was not significantly different from that for all the endoscopies in the oral first/nasal second group [1193 (188) s]. Because there is no advantage or disadvantage to be gained in starting to learn either type of endoscopy first, graduated training programmes can be planned according to the availability of suitable patients for fibreoptic intubation, without instructors needing to consider whether trainees make better progress if they learn one technique before the other.

Single mothers in low-wage jobs: financial strain, parenting, and preschoolers' outcomes

Using data from an ongoing study of 93 single Black mothers of preschoolers who had been welfare recipients, but were employed in low-wage jobs at baseline, this study tests a model of how maternal education, economic conditions (earnings and financial strain), and the availability of instrumental support influence maternal psychological functioning, parenting, and child development. Results indicate that maternal educational attainment was positively associated with earnings, which, together with instrumental support, were negatively associated with financial strain. Financial strain, in turn, was implicated in elevated levels of depressive symptoms, which were directly and negatively implicated in parenting quality. The quality of parenting was associated with children's behavior problems and preschool ability. Specifically, mothers with higher scores on the HOME scale, our measure of involved, supportive parenting, had children with fewer behavior problems and better preschool ability.

Development of a risk assessment methodology for evaluating potential impacts associated with contaminated mud disposal in the marine environment

In order to assess impacts associated with disposal of contaminated mud arising from Hong Kong's dredging and reclamation projects, a methodology has been formulated to determine the level of risk posed by consumption of seafood/marine prey species to humans and to the Chinese White Dolphin (Sousa chinensis). This methodology improves on previously used techniques by incorporating risks for organic contaminants, accounting for doses from sources other than seafood, and incorporating additional local knowledge on Sousa chinensis behaviour. It thus represents an advance in risk assessment techniques and a new integration of risk assessment and monitoring in environmental management.

A gene for ataxic cerebral palsy maps to chromosome 9p12-q12

Cerebral palsy (CP) has an incidence of approximately 1 in 750 births, although this varies between ethnic groups. Genetic forms of the disease account for about 2% of cases in most countries, but contribute a larger proportion in certain sub-types of the condition and in populations with a large proportion of consanguineous marriages. Ataxic cerebral palsy accounts for 5-10% of all forms of CP and it is estimated that approximately 50% of ataxic cerebral palsy is inherited as an autosomal recessive trait. We have identified a complex consanguineous Asian pedigree with four children in two sibships affected with ataxic cerebral palsy and have used homozygosity mapping to map the disorder in this family. A genome-wide search was performed using 343 fluorescently labelled polymorphic markers and linkage to chromosome 9p12-q12 was demonstrated. A maximum Lod score of 3.4 was observed between the markers D9S50 and D9S167 using multipoint analysis, a region of approximately 23cM. We have identified a family that segregates both ataxic CP and ataxic diplegia and have mapped the genetic locus responsible in this family to chromosome 9p12-q12. The identification of gene(s) involved in the aetiology of CP will offer the possibility of prenatal/premarital testing to some families with children affected with the disorder and will greatly increase our understanding of the development of the control of motor function.

beta 3: an additional auxiliary subunit of the voltage-sensitive sodium channel that modulates channel gating with distinct kinetics

The voltage-sensitive sodium channel confers electrical excitability on neurons, a fundamental property required for higher processes including cognition. The ion-conducting alpha-subunit of the channel is regulated by two known auxiliary subunits, beta1 and beta2. We have identified rat and human forms of an additional subunit, beta3. It is most closely related to beta1 and is the product of a separate gene localized to human chromosome 11q23.3. When expressed in Xenopus oocytes, beta3 inactivates sodium channel opening more slowly than beta1 does. Structural modeling has identified an amino acid residue in the putative alpha-subunit binding site of beta3 that may play a role in this difference. The expression of beta3 within the central nervous system differs significantly from beta1. Our results strongly suggest that beta3 performs a distinct neurophysiological function.

A third novel locus for primary autosomal recessive microcephaly maps to chromosome 9q34

Primary autosomal recessive microcephaly is a clinical diagnosis of exclusion in an individual with a head circumference >/=4 SDs below the expected age-and-sex mean. There is associated moderate mental retardation, and neuroimaging shows a small but structurally normal cerebral cortex. The inheritance pattern in the majority of cases is considered to be autosomal recessive. Although genetic heterogeneity for this clinical phenotype had been expected, this has only recently been demonstrated, with the mapping of two loci for autosomal recessive primary microcephaly: MCPH1 at 8p and MCPH2 at 19q. We have studied a large multiaffected consanguineous pedigree, using a whole-genome search, and have identified a third locus, MCPH3 at 9q34. The minimal critical region is approximately 12 cM, being defined by the markers cen-D9S1872-D9S159-tel, with a maximum two-point LOD score of 3.76 (recombination fraction 0) observed for the marker D9S290.

Characterisation of the gene for Drosophila amphiphysin

A sequence similarity search of the Drosophila nucleotide database using vertebrate amphiphysin as a query identified a cDNA that encodes a Drosophila amphiphysin. The predicted protein has conserved sequence domains that should enable it to dimerise and bind to dynamin. Structural modelling suggests that the Src-homology-3 (SH3) domains of vertebrate and Drosophila amphiphysins are highly similar, supporting the putative ability of the latter to bind dynamin. However, the fly amphiphysin shows less conservation to sequences in the vertebrate amphiphysins that bind other endocytic components such as clathrin, AP-2 and endophilin. Amphiphysin is a single-copy gene that maps to position 49B on polytene chromosomes. Messenger RNA of this amphiphysin is expressed widely during embryogenesis and has elevated expression in a number of sites including the foregut, hindgut and epidermis, but not in the central nervous system. Taken together, these data are consistent with a role for Drosophila amphiphysin in endocytosis, but the details of this role may differ from that of vertebrate amphiphysins.

The second locus for autosomal recessive primary microcephaly (MCPH2) maps to chromosome 19q13.1-13.2

Primary microcephaly is a clinical diagnosis made when an individual has a head circumference of greater than 3 standard deviations below the age and sex matched population mean, mental retardation but without other associated malformations and no apparent aetiology. The majority of cases of primary microcephaly exhibit an autosomal recessive mode of inheritance. We now demonstrate the genetic heterogeneity of this condition with the identification of a second primary microcephaly locus (MCPH2) on chromosome 19q13.1-13.2 in two multi-affected consanguineous families. The minimum critical region containing the MCPH2 locus is defined by the polymorphic markers D19S416 and D19S420 spanning a region of approximately 7.6 cM.

A PC12 variant lacking regulated secretory organelles: aberrant protein targeting and evidence for a factor inhibiting neuroendocrine gene expression

A variant of the PC12 pheochromocytoma cell line (termed A35C) has been isolated that lacks regulated secretory organelles and several constituent proteins. Northern and Southern blot analyses suggested a block at the transcriptional level. The proprotein-converting enzyme carboxypeptidase H was synthesised in the A35C cell line but was secreted by the constitutive pathway. Transient transfection of A35C cells with cDNAs encoding the regulated secretory proteins dopamine beta-hydroxylase and synaptotagmin I resulted in distinct patterns of mistargeting of these proteins. It is surprising that hybrid cells created by fusing normal PC12 cells with A35C cells exhibited the variant phenotype, suggesting that A35C cells express an inhibitory factor that represses neuroendocrine-specific gene expression.

The effects of nonresident father involvement on single black mothers and their young children

Using data from an ongoing study of current and former welfare recipients and their preschool children, the study discussed in this article examined the influence of the presence of nonresident fathers on the well-being and development of 188 low-income, employed and nonemployed single black mothers and their three- and four-year-old children. There is evidence that involvement by nonresident fathers has positive effects on maternal depression symptoms and child problem behaviors. The data show that maternal employment status seems to affect nonresident fathers' relations with single black mothers and their young children. It also seems to make a difference in the mothers' psychological well-being. Policy implications are discussed.

The laryngeal mask airway as an aid to training in fibreoptic nasotracheal endoscopy

We have investigated the extent to which the laryngeal mask airway, when used as an aid to fibreoptic nasotracheal video-endoscopy training, could reduce endoscopy apnoeic time in anaesthetised, paralysed oral surgery patients. Twenty anaesthetic trainees were randomly allocated to the laryngeal mask airway or control group. Laryngeal mask airway group endoscopies were performed in three stages following insertion of the laryngeal mask airway; stage 1: nasendoscopy, with the lungs ventilated automatically through the laryngeal mask airway; stage 2: removal of the laryngeal mask airway; stage 3: pharyngoscopy, larygoscopy and tracheoscopy. Control group endoscopies were performed conventionally, in one stage. Each trainee performed five nasotracheal intubations. Though total endoscopy time in the laryngeal mask airway group (stage 1 + stage 2 + stage 3 times) was significantly longer (average 136 s vs. 108 s), apnoeic time (stage 2 + stage 3 times) was significantly shorter (average 59 s vs. 108 s) than endoscopy time in the control group. This application of the laryngeal mask airway may have a useful role to play in ensuring patient safety during early fibreoptic training.

Primary autosomal recessive microcephaly (MCPH1) maps to chromosome 8p22-pter

Primary (or "true") microcephaly is inherited as an autosomal recessive trait and is thought to be genetically heterogeneous. Using autozygosity mapping, we have identified a genetic locus (MCPH1) for primary microcephaly, at chromosome 8p22-pter, in two consanguineous families of Pakistani origin. Our results indicate that the gene lies within a 13-cM region between the markers D8S1824 and D8S1825 (maximum multipoint LOD score of 8.1 at D8S277). In addition, we have demonstrated the genetic heterogeneity of this condition by analyzing a total of nine consanguineous families with primary microcephaly.

Dissection of hepatic receptor-mediated endocytic pathways using self-generated gradients of iodixanol (Optiprep)

Iodixanol is a new, nonionic, iodinated density gradient medium which has an advantage over other similar media in that it rapidly forms self-generated gradients in vertical or near-vertical rotors. Endocytosis of 99mTc-labeled neogalactosyl albumin (99mTc-NGA), a synthetic ligand for the asialoglycoprotein receptor, was studied by administering the ligand as a short pulse to perfused rat livers operating under single-pass conditions. Intracellular processing was arrested at various times after the pulse and the resultant homogenate cleared of nuclei and heavy mitochondria by centrifugation at 3000 g for 10 min. After adjustment to 12.5% (w/v) iodixanol, the 3000 g supernatants were centrifuged at 350,000 g for 60 min to form the gradients in which early, clathrin-containing vesicles, low-density endosomes, and lysosomes were well-resolved. 99mTc-NGA bound to the sinusoidal membrane could be partially resolved from clathrin-containing vesicles by inclusion of 1 mM CaCl2 in the homogenization and gradient buffers. Two populations of early clathrin-containing vesicles could be resolved by rate-zonal centrifugation in preformed iodixanol gradients. Thus, iodixanol is an excellent density gradient medium for the rapid and efficient resolution of endosome compartments.

Effects of concerns about child care among single, employed black mothers with preschool children

This study investigated whether differences in child care arrangements and mothers' attitudes about leaving their child in nonmaternal care were associated with maternal psychological well-being and perceptions of children in a sample of single, employed, low-income, Black mothers who were former welfare recipients. Feelings of discomfort with regard to nonmaternal care were associated with higher levels of maternal depressive symptomatology, which, in turn, predicted more negative perceptions of children. Preference for employment and increased working hours were associated with greater life satisfaction. Maternal education and the gender of the child were important moderating variables. Type of child care arrangement was nonsignificant. Policy implications are discussed.

Clathrin proteins and recognition memory

Strong converging evidence indicates that the intermediate and medial part of the hyperstriatum ventrale (IMHV) of the chick forebrain is a site of recognition memory for the learning process of imprinting. Clathrin proteins have been implicated in synaptic plasticity. In the present study we demonstrate for the first time that they are involved in vertebrate learning. Chicks were trained by exposure to a conspicuous object and their preference for it versus a novel object subsequently measured as a preference score (an index of learning). Trained chicks with low preference scores were classed as "poor learners" and those with high preference scores as "good learners". An additional group of chicks was untrained ("dark-reared"). Tissue was removed from the left and right IMHV, hyperstriatum accessorium and posterior neostriatum 9.5 h or 24 h after training. Clathrin heavy chain and clathrin light chains a and b were assayed using sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting. In the IMHV, and only for clathrin heavy chain, was there a significant effect of training. The effect occurred 24 h but not 9.5 h after training, and was significant only in the left IMHV. In this region at 24 h, there was (i) significantly more clathrin heavy chain in good learners than in dark-reared chicks, and (ii) a significant positive correlation between the amount of clathrin heavy chain and preference score; the amount of protein present in the dark-reared chicks did not differ significantly from the amount predicted from the regression line for trained chicks performing at chance (preference score 50). These findings imply that for the left IMHV, visual experience per se, locomotor activity and other side effects of training did not affect the amount of clathrin heavy chain. Rather, the increase observed was a function of the amounts chick learned and, because it was delayed, is likely to be involved in long-term memory. The results for clathrin heavy chain taken together suggest that enhanced presynaptic events in the IMHV, possibly associated with an increase in synaptic vesicle release/uptake, are important in the recognition memory underlying imprinting.

Crystal structure of the breakage-reunion domain of DNA gyrase

DNA gyrase is a type II DNA topoisomerase from bacteria that introduces supercoils into DNA. It catalyses the breakage of a DNA duplex (the G segment), the passage of another segment (the T segment) through the break, and then the reunification of the break. This activity involves the opening and dosing of a series of molecular 'gates' which is coupled to ATP hydrolysis. Here we present the crystal structure of the 'breakage-reunion' domain of the gyrase at 2.8 A resolution. Comparison of the structure of this 59K (relative molecular mass, 59,000) domain with that of a 92K fragment of yeast topoisomerase II reveals a very different quaternary organization, and we propose that the two structures represent two principal conformations that participate in the enzymatic pathway. The gyrase structure reveals a new dimer contact with a grooved concave surface for binding the G segment and a cluster of conserved charged residues surrounding the active-site tyrosines. It also shows how breakage of the G segment can occur and, together with the topoisomerase II structure, suggests a pathway by which the T segment can be released through the second gate of the enzyme. Mutations that confer resistance to the quinolone antibacterial agents cluster at the new dimer interface, indicating how these drugs might interact with the gyrase-DNA complex.