Autistic behavior in young boys with fragile X syndrome

A sample of 57 boys with fragile X syndrome (fraX) between the ages of 24 and 133 months was rated using the Childhood Autism Rating Scale (CARS) to assess the extent to which autism and autistic features were evident in a young population. Fourteen subjects (approximately 25% of the sample) scored above the cutoff for autism, suggesting a relatively high incidence of autistic behavior. All but 2 of these 14 were in the mildly or moderately autistic range, however, and only a few items received severe ratings, suggesting that severe autism is relatively rare in fraX, at least during the early years. The CARS resulted in a continuum of autistic ratings in the fraX population, but no particular items on the CARS contributed disproportionately to autism ratings. A visual comparison of ratings on an autistic, non-fraX sample revealed similar profiles of ratings, suggesting that differentiating fraX and autism on the basis of CARS ratings is not likely. Within the fraX group, chronological age and socioeconomic status did not correlate with CARS ratings, but severity of delay was strongly related, such that more severely delayed children scored higher (more autistic) on the CARS.

Measuring oxygen tension in the anterior chamber of rabbits

PURPOSE

Measuring the concentration of oxygen in the aqueous humor without penetrating the eye would provide a new dimension in understanding aqueous humor and corneal dynamics. In this study a preinvasive method was developed for determining the cameral oxygen concentration in anesthetized rabbits by measuring the excited-state lifetime of a phosphorescent dye.

METHODS

A scanning ocular fluorometer was designed to excite phosphorescence with a brief flash of light and to measure the decay of luminescence for as long as 1000 microsec after excitation. The measurement window was scanned through the depth of the anterior chamber or fixed at the mid-anterior chamber. A depot of the phosphorescent dye Pd-uroporphyrin was injected into the vitreous of eight pigmented rabbits, and within a few days the dye was measurable in the anterior chamber. The excited-state lifetime of this dye is inversely correlated to oxygen concentration and was calibrated by measuring the lifetime of dye in cuvettes equilibrated with oxygen-nitrogen mixtures. Oxygen tensions were determined from lifetimes measured in the open eye, under a polymethylmethacrylate (PMMA) contact lens, under two oxygen-permeable contact lenses, and immediately after lid closure.

RESULTS

Oxygen tension in the mid-anterior chamber before placing a PMMA contact lens was 23 +/- 3 mm Hg (mean +/- SD; n = 6). After 20 minutes of PMMA lens wear, oxygen tension decreased to 4 +/- 2 mm Hg. When the focal diamond was scanned through the anterior chamber, oxygen tension was 24 +/- 5 mm Hg near the corneal endothelium and decreased to 17 +/- 8 mm Hg near the crystalline lens. Under the PMMA contact lens this gradient reversed: Oxygen tensions near the endothelium and lens were 3 +/- 2 mm Hg and 6 +/- 2 mm Hg, respectively. Lid closure for 10 minutes or longer decreased the mid-anterior chamber oxygen tension from 21 +/- 2 mm Hg (n = 19 measurements from seven animals) to 10 +/- 3 mm Hg (n = 15 measurements from five animals).

CONCLUSIONS

Measuring excited-state lifetime of phosphorescent dyes in the anterior chamber provides a useful method for determining oxygen concentration in vivo, without penetrating the eye. Cameral oxygen tension under PMMA contact lenses are significantly lower than in the uncovered eye. The profile of oxygen tension through the anterior chamber suggests that oxygen is supplied transcorneally to the aqueous humor.

Otitis media, the caregiving environment, and language and cognitive outcomes at 2 years

OBJECTIVE

To examine the relationship between otitis media with effusion (OME) and associated hearing loss between 6 and 24 months of age and children's language and cognitive development at 2 years of age.

STUDY DESIGN

A prospective cohort design in which 86 African-American infants who attended group child-care centers were recruited between 6 and 12 months of age. Between 6 and 24 months, assessments included serial ear examinations using otoscopy and tympanometry, serial hearing tests, two ratings of the childrearing environment at home and in child care, and language and cognitive outcomes at 2 years.

RESULTS

Children experienced either unilateral or bilateral OME an average of 63% and reduced hearing sensitivity an average of 44% of the time between 6 and 24 months of age. Although proportion of time with OME or with hearing loss was modestly correlated with measures of language and cognitive skills, these relationships were no longer significant when the ratings of the home and child-care environments were also considered. Children with more OME or hearing loss tended to live in less responsive caregiving environments, and these environments were linked to lower performance in expressive language and vocabulary acquisition at 2 years.

CONCLUSIONS

Both OME and hearing loss were more strongly related to the quality of home and child-care environments than to children's language and cognitive development. Study results might be explained either by suggesting that children in less responsive caregiving environments experience conditions that make them more likely to experience OME and/or by suggesting that it may be more difficult for caregivers to be responsive and stimulating with children with more OME.

Interactions of African American infants and their mothers: relations with development at 1 year of age

The relationships between aspects of mother-infant interaction and both communication and cognitive skills at 1 year of age were examined in 92 African American dyads, of whom 64 (70%) fell below the poverty line. Ratings of warmth, sensitivity, responsiveness, encouragement of initiative, stimulation, and elaborativeness during a semistructured play interaction were correlated with measures of global cognition, expressive and receptive communication, and communication use. The overall quality of the home environment and maternal ratings of stimulation and elaborativeness were the most consistent correlates of infant communication measures. Relationships were stronger in middle-income than lower-income dyads. These results support the linkage of didactic and functional aspects of maternal behavior to cognitive and communication skills at 1 year of age for African American infants.

Ltx1, a mouse locus that influences the susceptibility of macrophages to cytolysis caused by intoxication with Bacillus anthracis lethal factor, maps to chromosome 11

The lethal factor (LF) toxin that is produced by Bacillus anthracis plays an important role in the pathogenesis of anthrax. LF has mononuclear phagocyte-specific intoxicating effects that are not well understood. We have identified genetic differences in inbred mouse strains that determine whether their cultured macrophages are susceptible to the cytolytic effect of LF intoxication. Our identification of resistant and susceptible mouse strains enabled us to analyse crosses between these strains and to map a single responsible gene (called Ltx1) to chromosome 11. Ltx1 probably influences intoxication events that occur after the delivery of LF to the cytosol, as all mouse macrophages are killed by polypeptides containing the catalytic domain of Diphtheria toxin fused to the domain of LF required for cytosolic transport. Furthermore, the susceptibility phenotype is dominant to resistance, suggesting that resistance is caused by an absence of or polymorphism in a molecule that acts jointly with, or downstream of, the activity of LF. Our mapping of Ltx1 is a crucial first step in its positional cloning, which will provide more information about the mechanism of LF intoxication.

Effects of melatonin, its precursors and derivatives on the growth of cultured human uveal melanoma cells

The effects of melatonin, its precursors and derivatives on the growth of cultured human uveal melanoma cells were studied. The melanoma cells were plated into 24-well plates. Melatonin, its 6-hydroxy or 6-chloro derivative, serotonin, tryptophan or kynurenine was added to the medium in concentrations of 0.001 to 1000 nM. After 5 days the cells were detached, counted, and compared with the controls. Melatonin inhibited the growth of uveal melanoma cell lines in a dose-dependent manner (0.1-10 nM). This growth inhibition occurred at concentrations of melatonin (2 nM) found in human aqueous humour. The melatonin derivatives also inhibited the growth of uveal melanoma cells; 6-chloromelatonin was more potent than melatonin and 6-hydroxymelatonin was the least active (6-chloromelatonin > melatonin > 6-hydroxymelatonin). The precursors of melatonin (tryptophan and serotonin) and the abnormal metabolite of tryptophan (kynurenine) did not inhibit the growth of the melanoma cells, indicating that changes to the metabolic processes of melatonin may play a role in the pathogenesis of uveal melanoma.

Temporal variability in global self-esteem and specific self-evaluation as prospective predictors of emotional distress: specificity in predictors and outcome

Recent studies have found that temporal variability and reactivity in self-esteem (SE) are associated with risk for depressive symptoms subsequent to life stress. It is unclear, however, whether it is variability uniquely in SE that is critical, or whether variability in other domains, such as specific self-evaluation (SSE) and affect, would show similar effects. Further, the specificity of these effects to depression is unknown. In the present study, initially nondepressed women completed 7 daily ratings of SE, SSE, and affect. Over a 6-week prospective interval, the interactions of stressful life events and variability in both SE and SSE predicted changes in depression, particularly in individuals with more severe worst lifetime episodes of depressive symptoms. These effects were independent of average level of SE and SSE, as well as neuroticism and self-concept uncertainty. In contrast, variability in affect failed to predict changes in depression in interaction with life stress. Finally, none of the predictor variables interacted with stressful life events in predicting changes in anxiety.

Pulse radiolysis studies of melatonin and chloromelatonin

The endogenous indole melatonin and the melatonin receptor agonist 6-chloromelatonin block the proliferation of both dermal and uveal melanoma cells by mechanisms that may involve redox reactions. The interactions of hydrated electrons, the azide radical, hydroxyl radicals and superoxide with melatonin and its 6-chloro analogue have been studied using the technique of pulse radiolysis. The reaction rate constants of eaq- and N3 x with these compounds were found to be dependent on substitution at the sixth position. The rate constants for reaction of 6-chloromelatonin and melatonin with solvated electrons are 4.5 x 10(9) M-1 s-1 and 4.2 x 10(8) M-1 s-1, respectively. The reaction rate constants of N3 x with malatonin and chloromelatonin are 9.8 x 10(9) M-1 s-1 and 3.5 x 10(9) M-1 s-1 and 3.5 x 10(9) M-1 s-1, respectively. Melatonin and 6-chloromelatonin react with hydroxyl radicals at near diffusion controlled rates (1.3 x 10(10) M-1 s-1, 8.2 x 10(9) M-1 s-1). Melatonin and 6-chloromelatonin did not react with superoxide radicals and we calculate an upper limit of 1.0 x 10(4) M-1 s-1 for the rate constant for reaction of melatonin and 6-chloromelatonin with superoxide ion.

Temporal variability in global self-esteem and specific self-evaluation as prospective predictors of emotional distress: specificity in predictors and outcome

Recent studies have found that temporal variability and reactivity in self-esteem (SE) are associated with risk for depressive symptoms subsequent to life stress. It is unclear, however, whether it is variability uniquely in SE that is critical, or whether variability in other domains, such as specific self-evaluation (SSE) and affect, would show similar effects. Further, the specificity of these effects to depression is unknown. In the present study, initially nondepressed women completed 7 daily ratings of SE, SSE, and affect. Over a 6-week prospective interval, the interactions of stressful life events and variability in both SE and SSE predicted changes in depression, particularly in individuals with more severe worst lifetime episodes of depressive symptoms. These effects were independent of average level of SE and SSE, as well as neuroticism and self-concept uncertainty. In contrast, variability in affect failed to predict changes in depression in interaction with life stress. Finally, none of the predictor variables interacted with stressful life events in predicting changes in anxiety.

Effects of paramagnetic cations on the nonexponential spin-lattice relaxation of rare spin nuclei in solids

Nonexponential spin-lattice relaxation is often observed for rare spin nuclei in the solid state. Deviation from single-component decay may be amplified by the coupling of rare spin nuclei to paramagnetic centers. Nonexponential spin-lattice relaxation was observed in derivatized silica gels resins. This phenomenon was localized and enhanced when paramagnetic transition metal cations were bound to surface functional groups. A stretched exponential analysis method was determined to be robust in fitting nonexponential relaxation curves for silica gels both with and without bound paramagnetic ions. Spin-lattice relaxation rates (T1(-1)) for functional group nuclei increased as a function of percent surface coverage with metal ion. The magnitude of the relaxation rate increase was dependent upon internuclear distances from the paramagnetic center. At low surface coverages, a semi-random distribution of paramagnetic centers increased the degree of stretching of spin-lattice relaxation decays, as measured by decreases in the calculated stretching parameter beta. At higher surface coverages, calculated beta values reached a limiting value, indicating that while the spin-diffusion mechanism in metal-exchanged silica gels is restricted, it is not completely diminished.

Lifetime episodes of dysphoria: gender, early childhood loss and personality

The roles of gender, early childhood loss and personality as risk factors for lifetime episodes of dysphoria were examined in a large sample of college students (N = 557). Dysphoria classifications were based on the Inventory to Diagnose Depression (IDD) and the IDD-Lifetime Version. Brief dysphoria was defined as meeting DSM-III-R symptom criteria for major depression without meeting the two-week duration criteria, whereas protracted dysphoria required that the duration criteria were also met. Although females reported higher levels of depressive symptoms and neuroticism than did males, and were more likely to have a lifetime history of episodes of dysphoria, males were more susceptible to the adverse effects of early childhood loss. Males with loss were more likely to have a history of protracted dysphoria and to report higher levels of neuroticism than were males who did not experience an early parental loss. Neuroticism, in turn, acted as a trait vulnerability characteristic to episodes of dysphoria in both males and females. Interestingly, the effects of gender on lifetime experience of dysphoria were mediated by neuroticism: females' increased vulnerability to episodes of dysphoria was due to their elevated levels of neuroticism.

Melatonin inhibits growth of cultured human uveal melanoma cells

The effects of melatonin on the growth of human uveal melanoma cells were studied in vitro. Three continuous uveal melanoma cell lines were tested. Cells were plated into multi-well plates. After 24 h, melatonin was added to the medium at concentrations from 0.001 to 1000 nM. Cells were collected and counted after 5 days and compared with the controls. Melatonin inhibited the growth of melanoma cells in a dose-dependent manner (0.1-10 nM) with a mean inhibition rate of 50%. The uptake of bromodeoxyuridine (BrdU) by the melanoma cells was also measured. Melatonin inhibited the uptake of BrdU of melanoma cells at concentrations of 0.1-10 nM with a mean inhibition rate of 40%. These results indicate that melatonin may offer a new treatment for metastatic uveal melanoma.

Life stress and treatment course of recurrent depression: II. Postrecovery associations with attrition, symptom course, and recurrence over 3 years

Life stress was studied in relation to postrecovery attrition, symptom course, and recurrence of depression over 3 years. Participants were 67 individuals with recurrent depression who had responded to treatment. Life stress was assessed for the prior 12 weeks at acute treatment entry (T1), initial recovery (T2), and after 17 weeks of sustained recovery (T3). Severe life events at T1 predicted greater attrition, a more favorable postrecovery symptom course, and a lower likelihood of recurrence over 3 years. Life stress at T2 was not predictive of outcomes. Finally, undesirable life events at T3 tended to predict a worse symptom course and a higher likelihood of recurrence, particularly for individuals on medication. The findings are discussed in terms of (a) different processes influenced by life stress over time and (b) limitations of existing longitudinal research for studying the effects of life stress over prolonged intervals.

The effect of L-cysteine and N-acetylcysteine on porphyrin/heme biosynthetic pathway in cells treated with 5-aminolevulinic acid and exposed to radiation

The effects of L-cysteine (LC) and N-acetylcysteine (NAC) on porphyrin accumulation in a human dermal microvascular endothelial cell line (HMEC-1) and a human epidermoid carcinoma cell line (A431) loaded with 5-aminolevulinic acid (ALA) and exposed to ultraviolet A (UVA) and blue light radiation were determined. Porphyrin accumulation was decreased in the presence of 0.1-7.5 mM LC (24.8%-31.4% suppression in HMEC-1 cell; 35.8%-48.9% suppression in A431 cells), and in the presence of 0.1-10.0 mM NAC (30.9%-58.0% suppression in HMEC-1 cells; 8.5%-45.3% in A431 cells). The suppression occurred in a LC or NAC dose-dependent fashion. The above was associated with partial reversal of suppression of ferrochelatase (FeC) activity in HMEC-1 cells and in A431 cells. As compared to FeC activity in cells treated with ALA and irradiation, enzyme activity was higher (by 31.9%-62.1%) in the presence of LC (1.0 mM or 5.0 mM) and in the presence of NAC (1.0 mM or 5.0 mM). These data indicate that LC and NAC have protective effects on porphyrin- and irradiation-induced diminution of FeC activity in HMEC-1 cells and A341 cells in vitro.

Life stress and treatment course of recurrent depression: II. Postrecovery associations with attrition, symptom course, and recurrence over 3 years

Life stress was studied in relation to postrecovery attrition, symptom course, and recurrence of depression over 3 years. Participants were 67 individuals with recurrent depression who had responded to treatment. Life stress was assessed for the prior 12 weeks at acute treatment entry (T1), initial recovery (T2), and after 17 weeks of sustained recovery (T3). Severe life events at T1 predicted greater attrition, a more favorable postrecovery symptom course, and a lower likelihood of recurrence over 3 years. Life stress at T2 was not predictive of outcomes. Finally, undesirable life events at T3 tended to predict a worse symptom course and a higher likelihood of recurrence, particularly for individuals on medication. The findings are discussed in terms of (a) different processes influenced by life stress over time and (b) limitations of existing longitudinal research for studying the effects of life stress over prolonged intervals.

Adult attachment security and symptoms of depression: the mediating roles of dysfunctional attitudes and low self-esteem

Three studies investigated the relation between adult attachment security and symptoms of depression. Study l examined the overall magnitude of the association between adult attachment and depression, and Studies 2 and 3 tested whether this relation was mediated by dysfunctional attitudes and low self-esteem. Results from the three studies were consistent with a mediation model. This model suggests that insecure adult attachment styles are associated with dysfunctional attitudes, which in turn predispose to lower levels of self-esteem. Such depletions in self-esteem are directly associated with increases in depressive symptoms over time. Insecure attachment appears to lead to depressive symptoms in adulthood through its impact on self-worth contingencies and self-esteem.

Recent developments in professional midwifery education and credentialing

The American College of Nurse-Midwives, (ACNM), as a membership organization, and the ACNM Certification Council (ACC), as a credentialing agency, pursue independent but allied missions of expanding access to education for the practice of midwifery, while adhering to established standard of quality for education and clinical practice. The following recent actions taken by these agencies are presented for the information of the membership. 1) The Assured Equivalency Option, a mechanism through which nurse-midwives educated in countries other than the United States can demonstrate their competency and, as needed, acquire additional requisite didactic knowledge or clinical skills, leading to eligibility for national certification examination, is detailed. 2) The rationale for adoption of the multiple-choice format for the criterion-referenced national certification examination in nurse-midwifery and the methods used to determine the validity and reliability of the examination are described. 3) The award of a time-limited credential to those newly certified is offered as a policy statement of the ACC. 4) Deliberations and decisions leading to development of guidelines for the accreditation of non-nurse-midwifery education programs and credentialing as a professional midwife are recounted.

Quality of center child care and infant cognitive and language development

The relations between quality of center-based child care and infant cognitive and language development were examined in a sample of 79 African-American 12-month-old infants. Both structural and process measures of quality of child care were collected through interviews with the center director and observation of the infant classroom. Results indicated that quality of infant care positively correlated with scores on standardized assessments of cognitive development (Bayley Scales of Infant Development), language development (Sequenced Inventory of Communication Development), and communication skills (Communication and Symbolic Behavior Scales). In addition, quality of care in child care centers and at home was positively related. Analyses that adjusted for this association between quality of care at home and in child care suggested that the process measure of quality of child care independently related to the infant's cognitive development, and one structural measure, the infant-adult ratio, independently related to the infant's overall communication skills. Neither child nor family factors was found to moderate the association between child care quality and infant development. These findings, in conjunction with the growing child care literature, suggest that researchers and policymakers should focus on how quality of child care can be improved to enhance, not impair, infant development.

Adult attachment security and symptoms of depression: the mediating roles of dysfunctional attitudes and low self-esteem

Three studies investigated the relation between adult attachment security and symptoms of depression. Study l examined the overall magnitude of the association between adult attachment and depression, and Studies 2 and 3 tested whether this relation was mediated by dysfunctional attitudes and low self-esteem. Results from the three studies were consistent with a mediation model. This model suggests that insecure adult attachment styles are associated with dysfunctional attitudes, which in turn predispose to lower levels of self-esteem. Such depletions in self-esteem are directly associated with increases in depressive symptoms over time. Insecure attachment appears to lead to depressive symptoms in adulthood through its impact on self-worth contingencies and self-esteem.

A comparison of conflict tactics in the supervisory process

This study investigated three different tactics clinical supervisors in communication disorders predicted they would use in a specific conflict situation. One hundred-sixty supervisors were asked to read one of three case scenarios describing a conflict situation within the supervisory process. All scenarios depicted a student-clinician who had not completed a reading assignment requested by the supervisor. The scenarios differed only in the supervisee's response to the supervisor's question about the incomplete assignment. Subjects were asked to indicate how likely they might be to use each of 15 comments that reflected categories of conflict tactics: avoidance, competitive, or collaborative tactics. Supervisors' choice of tactics differed depending on the response of the supervisee. Overall, supervisors most often chose collaborative responses, followed by avoidance responses and (least often) competitive responses. Implications are discussed in terms of impact on the supervisory process in communication disorders.

Prospective surveillance for otitis media with effusion among black infants in group child care

OBJECTIVE

To document the prevalence of otitis media with effusion (OME) in 102 black children observed prospectively between 6 and 24 months of age.

METHODS

Study children attended nine different center-based child care facilities. Middle ear status was assessed by pneumatic otoscopy and tympanometry every 2 weeks.

RESULTS

All children, except one, had OME during the period of observation. The proportion of child-examinations revealing bilateral OME ranged from 76% between 6 and 12 months of age to 30% between 21 and 24 months of age. Effusions were considered purulent in only 13% of examinations revealing middle ear fluid. The mean incidence of purulent OME was 2.13 episodes per child per year. Sixty-six children had at least 4 months of continuous bilateral OME during the period of observation; 57 were followed without placement of tympanostomy tubes. Bilateral OME had resolved before the second birthday in 95% of these children, and within 3 months of achieving the 4-month criterion in 50% of subjects.

CONCLUSIONS

Persistent bilateral OME occurs commonly between 6 and 18 months of age in infants who enter group child care during the first year of life. In this study, spontaneous resolution of bilateral effusion by 2 years of age was typical.