Efficacy of a Novel Metaldehyde Application Method to Control the Brown Garden Snail, Cornu aspersum (Helicidae), in South Africa

Baitchain is a novel molluscicide system that consists of metaldehyde pellets arranged on a cord and is designed to be tied around the base of tree trunks and act as a physical and chemical control method for molluscs. In this study, Baitchain is tested in a South African apple orchard and compared with traditional metaldehyde pellets (Sluggit) applied to the soil surface to determine the efficacy of the products against the brown garden snail, Cornu aspersum (Helicidae). The products were applied at two different concentrations, including 15 g/kg (Baitchain 15 and Sluggit 15) and 40 g/kg (Baitchain 40 and Sluggit 40) metaldehyde, and the products were either applied on their own, or in combination. Both treatments at 40 g/kg metaldehyde caused significant snail mortality when applied either on their own or in combination. However, significant mortality was also achieved by Baitchain 15 when applied on its own as well as in combination with Sluggit 15. The increased efficacy achieved by using Baitchain, even at the lower concentration, indicates that this novel method offers a viable physical and chemical control option for molluscs and could be incorporated as part of an integrated pest management strategy in South Africa, as well as other parts of the world.

Hemodialysis Arteriovenous Fistulas: A Nineteenth Century View of a Twenty First Century Problem

This is a literature review which approaches the problem of successful use of arteriovenous fistulas for dialysis within the construct of Virchow's triad. By organizing the literature with regard to Virchow's concepts of blood flow, vascular injury, and thrombophilia an improved understanding arteriovenous fistula placement, maintenance and repair can be obtained. This process is designed to increase understanding and options for treatment by looking at this problem and using scientific knowledge gained in cardiology, oncology and vascular surgery medicine. Future approaches to fistulas will hopefully be a multifaceted and based in cellular pathophysiology as well as surgical and radiologic interventions and repairs.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

Safety and efficacy of oxandrolone in growth hormone-treated girls with Turner syndrome: evidence from recent studies and recommendations for use

There has been no consensus regarding the efficacy and safety of oxandrolone (Ox) in addition to growth hormone (GH) in girls with Turner syndrome (TS), the optimal age of starting this treatment, or the optimal dose. This collaborative venture between Dutch, UK and US centers is intended to give a summary of the data from three recently published randomized, placebo-controlled, double-blind studies on the effects of Ox. The published papers from these studies were reviewed within the group of authors to reach consensus about the recommendations. The addition of Ox to GH treatment leads to an increase in adult height, on average 2.3–4.6 cm. If Ox dosages<0.06 mg/kg/day are used, side effects are modest. The most relevant safety concerns are virilization(including clitoromegaly and voice deepening) and a transient delay of breast development. We advise monitoring signs of virilization breast development and possibly blood lipids during Ox treatment, in addition to regular follow-up assessments for TS. In girls with TS who are severely short for age, in whom very short adult stature is anticipated,or in whom the growth rate is modest despite good compliance with GH, adjunctive treatment with Ox at a dosage of 0.03–0.05 mg/kg/day starting from the age of 8–10 years onward scan be considered.

Fluorescence imaging of nanoscale domains in polymer blends using stochastic optical reconstruction microscopy (STORM)

High-resolution fluorescence techniques that provide spatial resolution below the diffraction limit are attractive new methods for structural characterization of nanostructured materials. For the first time, we apply the super-resolution technique of Stochastic Optical Reconstruction Microscopy (STORM), to characterize nanoscale structures within polymer blend films. The STORM technique involves temporally separating the fluorescence signals from individual labeled polymers, allowing their positions to be localized with high accuracy, yielding a high-resolution composite image of the material. Here, we describe the application of the technique to demixed blend films of polystyrene (PS) and poly(methyl methacrylate) (PMMA), and find that STORM provides comparable structural characteristics as those determined by Atomic Force Microscopy (AFM) and scanning electron microscopy (SEM), but with all of the advantages of a far-field optical technique.

Metabolic effects of oral versus transdermal 17β-estradiol (E₂): a randomized clinical trial in girls with Turner syndrome

CONTEXT

The long-term effects of pure 17β-estradiol (E₂) depending on route of administration have not been well characterized.

OBJECTIVE

Our objective was to assess metabolic effects of oral vs transdermal (TD) 17β-E₂ replacement using estrogen concentration-based dosing in girls with Turner syndrome (TS).

PATIENTS

Forty girls with TS, mean age 16.7 ± 1.7 years, were recruited.

DESIGN

Subjects were randomized to 17β-E₂ orally or TD. Doses were titrated using mean E₂ concentrations of normally menstruating girls as therapeutic target. E₂, estrone (E₁), and E₁ sulfate (E₁S) were measured by liquid chromatography tandem mass spectrometry and a recombinant cell bioassay; metabolites were measured, and dual-energy x-ray absorptiometry scan and indirect calorimetry were performed.

MAIN OUTCOME

Changes in body composition and lipid oxidation were evaluated.

RESULTS

E₂ concentrations were titrated to normal range in both groups; mean oral dose was 2 mg, and TD dose was 0.1 mg. After 6 and 12 months, fat-free mass and percent fat mass, bone mineral density accrual, lipid oxidation, and resting energy expenditure rates were similar between groups. IGF-1 concentrations were lower on oral 17β-E₂, but suppression of gonadotropins was comparable with no significant changes in lipids, glucose, osteocalcin, or highly sensitive C-reactive protein between groups. However, E₁, E₁S, SHBG, and bioestrogen concentrations were significantly higher in the oral group.

CONCLUSIONS

When E₂ concentrations are titrated to the normal range, the route of delivery of 17β-E₂ does not affect differentially body composition, lipid oxidation, and lipid concentrations in hypogonadal girls with TS. However, total estrogen exposure (E₁, E₁S, and total bioestrogen) is significantly higher after oral 17β-E₂. TD 17β-E₂ results in a more physiological estrogen milieu than oral 17β-E₂ administration in girls with TS.

Clinical and molecular evaluation of SHOX/PAR1 duplications in Leri-Weill dyschondrosteosis (LWD) and idiopathic short stature (ISS)

CONTEXT

Léri-Weill dyschondrosteosis (LWD) is a skeletal dysplasia characterized by disproportionate short stature and the Madelung deformity of the forearm. SHOX mutations and pseudoautosomal region 1 deletions encompassing SHOX or its enhancers have been identified in approximately 60% of LWD and approximately 15% of idiopathic short stature (ISS) individuals. Recently SHOX duplications have been described in LWD/ISS but also in individuals with other clinical manifestations, thus questioning their pathogenicity.

OBJECTIVE

The objective of the study was to investigate the pathogenicity of SHOX duplications in LWD and ISS.

DESIGN AND METHODS

Multiplex ligation-dependent probe amplification is routinely used in our unit to analyze for SHOX/pseudoautosomal region 1 copy number changes in LWD/ISS referrals. Quantitative PCR, microsatellite marker, and fluorescence in situ hybridization analysis were undertaken to confirm all identified duplications.

RESULTS

During the routine analysis of 122 LWD and 613 ISS referrals, a total of four complete and 10 partial SHOX duplications or multiple copy number (n > 3) as well as one duplication of the SHOX 5' flanking region were identified in nine LWD and six ISS cases. Partial SHOX duplications appeared to have a more deleterious effect on skeletal dysplasia and height gain than complete SHOX duplications. Importantly, no increase in SHOX copy number was identified in 340 individuals with normal stature or 104 overgrowth referrals.

CONCLUSION

MLPA analysis of SHOX/PAR1 led to the identification of partial and complete SHOX duplications or multiple copies associated with LWD or ISS, suggesting that they may represent an additional class of mutations implicated in the molecular etiology of these clinical entities.

Consensus statement on the diagnosis and treatment of children with idiopathic short stature: a summary of the Growth Hormone Research Society, the Lawson Wilkins Pediatric Endocrine Society, and the European Society for Paediatric Endocrinology Workshop

OBJECTIVE

Our objective was to summarize important advances in the management of children with idiopathic short stature (ISS).

PARTICIPANTS

Participants were 32 invited leaders in the field.

EVIDENCE

Evidence was obtained by extensive literature review and from clinical experience.

CONSENSUS

Participants reviewed discussion summaries, voted, and reached a majority decision on each document section.

CONCLUSIONS

ISS is defined auxologically by a height below -2 sd score (SDS) without findings of disease as evident by a complete evaluation by a pediatric endocrinologist including stimulated GH levels. Magnetic resonance imaging is not necessary in patients with ISS. ISS may be a risk factor for psychosocial problems, but true psychopathology is rare. In the United States and seven other countries, the regulatory authorities approved GH treatment (at doses up to 53 microg/kg.d) for children shorter than -2.25 SDS, whereas in other countries, lower cutoffs are proposed. Aromatase inhibition increases predicted adult height in males with ISS, but adult-height data are not available. Psychological counseling is worthwhile to consider instead of or as an adjunct to hormone treatment. The predicted height may be inaccurate and is not an absolute criterion for GH treatment decisions. The shorter the child, the more consideration should be given to GH. Successful first-year response to GH treatment includes an increase in height SDS of more than 0.3-0.5. The mean increase in adult height in children with ISS attributable to GH therapy (average duration of 4-7 yr) is 3.5-7.5 cm. Responses are highly variable. IGF-I levels may be helpful in assessing compliance and GH sensitivity; levels that are consistently elevated (>2.5 SDS) should prompt consideration of GH dose reduction. GH therapy for children with ISS has a similar safety profile to other GH indications.

Idiopathic short stature: management and growth hormone treatment

In the management of ISS auxological, biochemical, psychosocial and ethical elements have to be considered. In boys with constitutional delay of growth and puberty androgens are effective in increasing height and sexual characteristics, but adult height is unchanged. GH therapy is efficacious in increasing height velocity and adult height, but the inter-individual variation is considerable. The effect on psychosocial status is uncertain. Factors affecting final height gain include GH dose, height deficit in comparison to midparental height, age and first year height velocity. In case of a low predicted adult height at the onset of puberty, addition of a GnRH analogue can be considered. Although GH therapy appears safe, long-term monitoring is recommended.

Overlapping numerical cognition impairments in children with chromosome 22q11.2 deletion or Turner syndromes

Children with one of two genetic disorders (chromosome 22q11.2 deletion syndrome and Turner syndrome) as well typically developing controls, participated in three cognitive processing experiments. Two experiments were designed to test cognitive processes involved in basic aspects numerical cognition. The third was a test of simple manual motor reaction time. Despite significant differences in global intellectual abilities, as measured by IQ tests, performance on the two numerical cognition tasks differed little between the two groups of children with genetic disorders. However, both performed significantly more poorly than did controls. The pattern of results are consistent with the hypothesis that impairments were not due to global intellectual ability but arose in specific cognitive functions required by different conditions within the tasks. The fact that no group differences were found in the reaction time task, despite significant differences in the standardized processing speed measure, further supports the interpretation that specific cognitive processing impairments and not global intellectual or processing speed impairments explain the pattern of results. The similarity in performance on these tasks of children with unrelated genetic disorders counters the view that numerical cognition is under any direct genetic control. Instead, our findings are consistent with the view that disturbances in foundational spatiotemporal cognitive functions contribute to the development of atypical representations and processes in the domains of basic magnitude comparison and simple numerical enumeration.

Pitfalls in the care of the very sick psychotic patients

NO ABSTRACT AVAILIBLE

Phase transitions in calcium nitrate thin films

Calcium carbonate is a ubiquitous mineral and its reactivity with indoor and outdoor air pollutants will contribute to the deterioration of these materials through the formation of salts that deliquesce at low relative humidity (RH). As shown here for calcium nitrate thin films, deliquescence occurs at even lower relative humidity than expected from bulk thermodynamics and lower than the recommended humidity for the preservation of artifacts and antiques.

Androgen-responsive aspects of cognition in girls with Turner syndrome

Turner syndrome (TS) represents a unique, sex hormone-deficient model in which to study the biological effects of androgen treatment (replacement) on cognition in females because TS girls have gonadal dysgenesis and absent ovarian androgen and estrogen production. We investigated the effects of androgen replacement therapy in TS girls, ages 10-14 yr, on cognitive function. A total of 64 TS girls were randomized to receive oxandrolone or placebo for 2 yr. They had a cognitive evaluation of four domains (verbal abilities, spatial cognition, executive function, and working memory) at baseline, 1, and 2 yr of the study. In addition, all subjects were examined for study safety every 6 months. Three of the four domains studied did not change significantly in response to oxandrolone treatment (verbal abilities, spatial cognition, and executive function). In contrast, the working memory summary score had a significant group by time interaction. The oxandrolone-treated group demonstrated improved performance after 2 yr, compared with the placebo group (P < 0.03). Minimal or no side effects were observed. In conclusion, oxandrolone treatment for 2 yr improves working memory in adolescent girls with TS. What this degree of improvement will mean in real life terms for TS girls remains to be determined.

Persistent cognitive deficits in adult women with Turner syndrome

BACKGROUND

Turner syndrome (TS) has a characteristic neurocognitive profile. Verbal abilities are, in general, normal; however, women with TS, as a group, have specific deficits in visual-spatial abilities, visual-perceptual abilities, motor function, nonverbal memory, executive function, and attentional abilities. Observed deficits could be caused by genetic or endocrine factors.

OBJECTIVE

To evaluate the specific cognitive deficits that appear to persist in adulthood, are not estrogen-responsive, and may be genetically determined.

METHODS

The cognitive performance of adult women with TS (n = 71) who were estrogen repleted was compared with verbal IQ- and socioeconomic status-matched female controls (n = 50). Sixty-one women with TS had ovarian failure and received estrogen replacement and 10 had preserved endogenous ovarian function and were not receiving estrogen replacement at the time of evaluation.

RESULTS

Similar to children and adolescents with TS, adults with TS have normal verbal IQ but have relative difficulty on measures of spatial/perceptual skills, visual-motor integration, affect recognition, visual memory, attention, and executive function despite estrogen replacement. These deficits are apparent in women with TS despite apparently adequate estrogen effect, either endogenous or by hormone replacement.

CONCLUSION

The cognitive phenotypes of adults with TS, with or without ovarian failure, are similar, indicating that estrogen replacement does not have a major impact on the cognitive deficits of adults with TS.

Psychosocial development in adolescents with Turner syndrome

Turner syndrome is a genetic condition in which part or all of the second X chromosome is missing. Our goal in this study was to examine the psychosocial adjustment of a sample of adolescent girls with Turner syndrome. Subjects included 122 girls with a diagnosis of Turner syndrome (TS) and a control group of 108 girls with no genetic disorder or chronic illness. Subjects were 13 to 18 years of age. A battery of questionnaires assessing social, academic, school, and behavioral functioning was administered. TS girls were seen as having significantly more problems in terms of social relationships and school progress and were more likely to meet criteria for attention-deficit hyperactivity disorder than control girls. The TS girls were also rated by a parent as less socially competent (e.g., fewer friends, less time with friends) than the control group. Social difficulties appear to be an area of vulnerability for TS girls. Counseling individuals with Turner syndrome and their families about the need to carefully develop and nurture social skills and relationships may prove useful in advancing the social adaptation of these young women.

Phenotypes Associated with SHOX Deficiency

Leri-Weill dyschondrosteosis (LWD) (MIM 127300) is a dominantly inherited skeletal dysplasia characterized phenotypically by Madelung wrist deformity, mesomelia, and short stature. LWD can now be defined genetically by haploinsufficiency of the SHOX (short stature homeobox-containing) gene. We have studied 21 LWD families (43 affected LWD subjects, including 32 females and 11 males, ages 3-56 yr) with confirmed SHOX abnormalities. We investigated the relationship between SHOX mutations, height deficit, and Madelung deformity to determine the contribution of SHOX haploinsufficiency to the LWD and Turner syndrome (TS) phenotypes. Also, we examined the effects of age, gender, and female puberty (estrogen) on the LWD phenotype. SHOX deletions were present in affected individuals from 17 families (81%), and point mutations were detected in 4 families (19%). In the LWD subjects, height deficits ranged from -4.6 to +0.6 SD (mean +/- SD = -2.2 +/- 1.0). There were no statistically significant effects of age, gender, pubertal status, or parental origin of SHOX mutations on height z-score. The height deficit in LWD is approximately two thirds that of TS. Madelung deformity was present in 74% of LWD children and adults and was more frequent and severe in females than males. The prevalence of the Madelung deformity was higher in the LWD vs. a TS population. The prevalence of increased carrying angle, high arched palate, and scoliosis was similar in the two populations. In conclusion, SHOX deletions or mutations accounted for all of our LWD cases. SHOX haploinsufficiency accounts for most, but not all, of the TS height deficit. The LWD phenotype shows some gender- and age-related differences.

A man who inherited his SRY gene and Leri-Weill dyschondrosteosis from his mother and neurofibromatosis type 1 from his father

We report on a man with neurofibromatosis type 1 (NF1) and Leri-Weill dyschondrosteosis (LWD). His father had NF1. His mother had LWD plus additional findings of Turner syndrome (TS): high arched palate, bicuspid aortic valve, aortic stenosis, and premature ovarian failure. The proband's karyotype was 46,X,dic(X;Y)(p22.3;p11.32). Despite having almost the same genetic constitution as 47,XXY Klinefelter syndrome, he was normally virilized, although slight elevation of serum gonadotropins indicated gonadal dysfunction. His mother's karyotype was mosaic 45,X[17 cells]/46,X,dic(X;Y)(p22.3;p11.32)[3 cells].ish dic(X;Y)(DXZ1 +,DYZ1 + ). The dic(X;Y) chromosome was also positive for Y markers PABY, SRY, and DYZ5, but negative for SHOX. The dic(X;Y) chromosome was also positive for X markers DXZ1 and a sequence < 300 kb from PABX, suggesting that the deletion encompassed only pseudoautosomal sequences. Replication studies indicated that the normal X and the dic(X;Y) were randomly inactivated in the proband's lymphocytes. LWD in the proband and his mother was explained by SHOX haploinsufficiency. The mother's female phenotype was most likely due to 45,X mosaicism. This family segregating Mendelian and chromosomal disorders illustrates extreme sex chromosome variation compatible with normal male and female sexual differentiation. The case also highlights the importance of karyotyping for differentiating LWD and TS, especially in patients with findings such as premature ovarian failure or aortic abnormalities not associated with isolated SHOX haploinsufficiency.

Molecular analysis of genes on Xp controlling Turner syndrome and premature ovarian failure (POF)

Monosomy X has been known to be the chromosomal basis of Turner syndrome (TS) for more than four decades. A large body of cytogenetic data indicates that most TS features are due to reduced dosage of genes on the short arm of the X chromosome (Xp). Phenotype mapping studies using molecular cytogenetic and genetic techniques are beginning to localize the Xp genes that are important for various TS features, and a comprehensive catalog of candidate genes is becoming available through the Human Genome Project and related research. It is now possible to assess the contributions of individual genes to the TS phenotype by mutational analysis of karyotypically normal persons with specific TS features. This strategy has succeeded in identifying a gene involved in short stature and is being applied to premature ovarian failure and other TS phenotypes.

Safety and effectiveness of Niaspan when added sequentially to a statin for treatment of dyslipidemia

Niaspan, when added to a stable dose of a statin in 66 subjects, was found to be safe and highly effective in improving lipid parameters. Subgroup analyses demonstrated its effectiveness in lowering low-density lipoprotein cholesterol in persons not at the National Cholesterol and Education Program low-density lipoprotein cholesterol target and in raising high-density lipoprotein cholesterol in persons with levels < 40 mg/dl.

Localization of MYOC transcripts in human eye and optic nerve by in situ hybridization

PURPOSE

To evaluate MYOC (myocilin) gene expression at the RNA level in normal intact human eyes and optic nerve using in situ hybridization.

METHODS

Normal human eyes and optic nerves from donors 62 to 83 years of age with no history of glaucoma were fixed, embedded in paraffin, and sectioned. Sections were hybridized with (35)S-labeled sense and antisense riboprobes derived from a full-length MYOC cDNA.

RESULTS

High levels of MYOC expression were observed throughout the trabecular meshwork as well as in the most anterior nonfiltering meshwork (Schwalbe's line), in the scleral spur, and in the endothelial lining of Schlemm's canal. MYOC transcripts were also detected in the anterior corneal stroma, in the ciliary muscle, beneath the anterior border of the iris, in the iris stroma, and in the sclera. Expression in the retrolaminar region of the optic nerve was present in the pial septa that divide the nerve fiber bundles, in the perivascular connective tissue surrounding the central retinal vessels, and in the dura mater, arachnoid, and pia mater of the meningeal sheath surrounding the optic nerve.

CONCLUSIONS

MYOC gene expression in the trabecular meshwork, Schlemm's canal, scleral spur, and ciliary muscle indicates a structural or functional role for myocilin in the regulation of aqueous humor outflow that may influence intraocular pressure. MYOC expression in the optic nerve suggests that changes in the structural, metabolic, or neurotropic support of the optic nerve may influence its susceptibility to glaucomatous damage.

Physical mapping of nine Xq translocation breakpoints and identification of XPNPEP2 as a premature ovarian failure candidate gene

Women with balanced translocations between the long arm of the X chromosome (Xq) and an autosome frequently suffer premature ovarian failure (POF). Two "critical regions" for POF which extend from Xq13-->q22 and from Xq22-->q26 have been identified using cytogenetics. To gain insight into the mechanism(s) responsible for ovarian failure in women with X;autosome translocations, we have molecularly characterized the translocation breakpoints of nine X chromosomes. We mapped the breakpoints using somatic cell hybrids retaining the derivative autosome and densely spaced markers from the X-chromosome physical map. One of the POF-associated breakpoints in a critical region (Xq25) mapped to a sequenced PAC clone. The translocation disrupts XPNPEP2, which encodes an Xaa-Pro aminopeptidase that hydrolyzes N-terminal Xaa-Pro bonds. XPNPEP2 mRNA was detected in fibroblasts that carry the translocation, suggesting that this gene at least partially escapes X inactivation. Although the physiologic substrates for the enzyme are not known, XPNPEP2 is a candidate gene for POF. Our breakpoint mapping data will help to identify additional candidate POF genes and to delineate the Xq POF critical region(s).

Use of estrogen in young girls with Turner syndrome: effects on memory

BACKGROUND

The Turner syndrome (TS) phenotype is characterized by a specific neurocognitive profile of normal verbal skills, impaired visual-spatial and visual-perceptual abilities, and impaired nonverbal more than verbal memory. We compared verbal and nonverbal memory in estrogen- and placebo-treated girls with TS (ages 7 to 9 years) and age-matched female controls.

METHODS

Children received either estrogen (ethinyl estradiol, 25 ng/kg/d) or placebo for 1 to 3 years (mean, 2.1+/-0.9 years) in a randomized, double-blind study. Memory and language tasks administered included the Wechsler Intelligence Scale for Children-Revised, Digit Span (forward and backward), the Children's Word List, the Denman Paragraph, the Peabody Picture Vocabulary Test, Boston Naming, immediate and delayed Recall of the Rey Complex Figure, Nonword Reading, Wide Range Achievement Test-Revised reading subtest, Verbal fluency, and the Token Test.

RESULTS

The estrogen-treated TS group performed better than the placebo-treated TS group for the Children's Word List immediate and delayed recall and the Digit Span backwards test (p<0.01 to 0.04), although the results were not significant after adjusting for multiple comparisons. The placebo-treated TS group performed less well than the controls for recall of Digit Span backward (p<0.0001; placebo-treated, 2.8+/-1.3; estrogen-treated, 3.4+/-1.2; and controls, 4.2+/-1.3) and immediate and delayed recall of the Children's Word List (delayed recall, p<0.0001; placebo-treated, 6.2+/-3.1; estrogen-treated, 8.0+/-2.9; and controls, 9.0+/-2.9). Performance for these measures was similar for the estrogen-treated TS group and the control group.

CONCLUSIONS

Estrogen replacement therapy in young girls with Turner Syndrome is associated with improved verbal and nonverbal memory. The optimal patient age, dose, and duration of estrogen replacement require further study.

An innovative approach to temporary hemodialysis vascular access

The National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF-DOQI) has set down explicit and extensive guidelines for temporary and permanent hemodialysis vascular access. It is now incumbent on the nephrologist to ensure compliance to these standards. Two of our interventional nephrologists performed 402 central venous access procedures over a 12-month period (November 1996 to October 1997) to test the hypothesis that increased control over insertion technique would improve outcome. All but eight of the procedures were successfully completed, resulting in a failure rate of 2%. The expected serious procedural complication rate outlined in the NKF-DOQI standards is 2%. Our complication rate was 0.7% if all procedures were accounted for and 0.89% for just internal jugular and subclavian catheters. We conclude that the use of interventionally trained nephrologists and strict control of technique can improve outcome in temporary vascular access procedures.

Prevention of a first stroke: a review of guidelines and a multidisciplinary consensus statement from the National Stroke Association

OBJECTIVE

To establish, in a single resource, up-to-date recommendations for primary care physicians regarding prevention strategies for a first stroke.

PARTICIPANTS

Members of the National Stroke Association's (NSA's) Stroke Prevention Advisory Board and Cedars-Sinai Health System Department of Health Services Research convened on April 9, 1998, in an open meeting. The conference attendees, selected to participate by the NSA, were recognized experts in neurology (9), cardiology (2), family practice (1), nursing (1), physician assistant practices (1), and health services research (2).

EVIDENCE

A literature review was carried out by the Department of Health Services Research, Cedars-Sinai Health System, Los Angeles, Calif, using the MEDLINE database search for 1990 through April 1998 and updated in November 1998. English-language guidelines, statements, meta-analyses, and overviews on prevention of a first stroke were reviewed.

CONSENSUS PROCESS

At the meeting, members of the advisory board identified 6 important stroke risk factors (hypertension, myocardial infarction [MI], atrial fibrillation, diabetes mellitus, blood lipids, asymptomatic carotid artery stenosis), and 4 lifestyle factors (cigarette smoking, alcohol use, physical activity, diet).

CONCLUSIONS

Several interventions that modify well-documented and treatable cardiovascular and cerebrovascular risk factors can reduce the risk of a first stroke. Good evidence for direct stroke reduction exists for hypertension treatment; using warfarin for patients after MI who have atrial fibrillation, decreased left ventricular ejection fraction, or left ventricular thrombus; using 3-hydroxy-3 methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors for patients after MI; using warfarin for patients with atrial fibrillation and specific risk factors; and performing carotid endarterectomy for patients with stenosis of at least 60%. Observational studies support the role of modifying lifestyle-related risk factors (eg, smoking, alcohol use, physical activity, diet) in stroke prevention. Measures to help patients improve adherence are an important component of a stroke prevention plan.

Evidence for a Turner syndrome locus or loci at Xp11.2-p22.1

Turner syndrome is the complex human phenotype associated with complete or partial monosomy X. Principle features of Turner syndrome include short stature, ovarian failure, and a variety of other anatomic and physiological abnormalities, such as webbed neck, lymphedema, cardiovascular and renal anomalies, hypertension, and autoimmune thyroid disease. We studied 28 apparently nonmosaic subjects with partial deletions of Xp, in order to map loci responsible for various components of the Turner syndrome phenotype. Subjects were carefully evaluated for the presence or absence of Turner syndrome features, and their deletions were mapped by FISH with a panel of Xp markers. Using a statistical method to examine genotype/phenotype correlations, we mapped one or more Turner syndrome traits to a critical region in Xp11.2-p22.1. These traits included short stature, ovarian failure, high-arched palate, and autoimmune thyroid disease. The results are useful for genetic counseling of individuals with partial monosomy X. Study of additional subjects should refine the localization of Turner syndrome loci and provide a rational basis for exploration of candidate genes.

Effects of estrogen on nonverbal processing speed and motor function in girls with Turner's syndrome

The Turner syndrome (TS) phenotype is characterized by a specific neurocognitive profile of normal verbal skills, impaired visual-spatial and/or visual-perceptual abilities, and difficulty with motor function. In the current study, we investigated motor function and nonverbal processing speed in estrogen- and placebo-treated girls (aged 10-12 years) with TS and in age-matched female controls. The goal of this study was to examine whether estrogen replacement therapy would reverse deficits in motor function and in nonverbal processing speed, a measure of the time required to perform certain disparate nonverbal tasks, in adolescent girls with TS. Children received either estrogen (ethinyl estradiol, 12.5-50 ng/kg.day), or placebo for durations of 1-7 yr (mean, 4.0 +/- 2.1 yr) in this randomized, double blind study. Cognitive and motor tasks administered included the Wechsler Intelligence Scale for Children-Revised; nonspatial, repetitive motor tasks (tapping and three tasks from the Paness); and spatially mediated motor tasks [nongrooved pegboard (Lafayette), pursuit rotor, visual-motor integration, and money street map]. Questionnaires administered included the Self-Concept Scale. The major result of this study was the positive estrogen treatment effect on nonverbal processing speed and speeded motor performance in 12-yr-old TS girls. That motor performance would be slower in estrogen-deficient TS females is consistent with previous studies of the influence of estrogen on motor function. Estrogen replacement is thus the most likely explanation for the improved motor speed and nonverbal processing time in the estrogen-treated TS girls compared to that in the placebo-treated TS girls. Whether these findings will influence the psychoeducational outcome or quality of life of females with TS is not yet known.

Transition to young adulthood in Ullrich-Turner syndrome: neurodevelopmental changes

Studies describing the neurocognitive profile of Ullrich-Turner syndrome (UTS) have focused primarily on neurodevelopmental changes in childhood and adolescence or in adults with UTS. The objective of the present study was to describe neurodevelopmental changes that occur in UTS females during the transition from adolescence to young-adulthood. The subjects included 99 females with UTS and 89 normal female controls matched for age and socioeconomic status. Subjects were between the ages of 13 and 21 years. All subjects received a battery of neurocognitive tests designed to assess general cognitive ability, academic achievement, memory, language, executive function, visual-spatial/perceptual and motor skills, affect recognition, attention, and motor skills. Results from our study indicated that females with UTS performed significantly less well than controls on measures of spatial/perceptual skills, visual-motor integration, affect recognition, visual memory, attentional abilities, and executive function, consistent with previous reports of cognitive abilities in adolescent UTS females. Moreover, our results indicate that decreased performance in some of these areas persists through late adolescence and into early adulthood while improvement occurs in other areas. It is possible that catch-up in certain cognitive deficiencies in UTS females represents a maturational/developmental lag. Alternatively, the neurodevelopmental changes that were observed in UTS females may result from the cumulative effects of estrogen replacement therapy during adolescence. Therapeutic interventions specific to the demands of young-adulthood are also discussed.

Turner syndrome and haploinsufficiency

Turner syndrome was one of the first human genetic disorders ascribed to haploinsufficiency but the identification of specific genes responsible for the phenotype has been problematic. Recent data point to several candidate genes, some new and some old, for specific aspects of the phenotype associated with monosomy X in humans.

Neuroblastoma and related tumors in Turner's syndrome

OBJECTIVES

The identification of constitutional cytogenetic abnormalities in patients with cancer may indicate loci of genes, abnormalities of which are responsible for tumor development or progression. This study was undertaken to determine whether girls with Turner's syndrome (TS) (partial or complete deletion of an X chromosome, short stature, gonadal dysgenesis) are at increased risk of neural crest-derived tumors.

STUDY DESIGN

Medical records of 394 patients with TS who were followed up at Thomas Jefferson Hospital and Children's Hospital of Pittsburgh were reviewed for documentation of TS phenotype, constitutional cytogenetics, and history of neuroblastoma or related tumors. Informative cases were reviewed for tumor pathology, primary site, disease stage, associated symptoms, treatment, and outcome.

RESULTS

Three patients were found to have neuroblastoma. A fourth child who died of neurofibrosarcoma was found to have extensive areas of ganglioneuroma, the benign counterpart of neuroblastoma, at autopsy. An additional four girls with TS and neuroblastoma were identified in the literature, as were two more patients with ganglioneuroma. These 10 patients ranged in age from 1 week to 16 10/12 years (median age, 3 years), and all but two of the children had localized lesions. Two of the seven children with neuroblastoma had courses complicated by opsoclonus-myoclonus, a syndrome found in fewer than 5% of all patients with neuroblastoma.

CONCLUSIONS

These data strongly suggest that girls with TS are predisposed to the development of neuroblastoma and related tumors. Because these tumors are often of limited stage and may be underdiagnosed, screening of urine of patients with TS for elevated catecholamine metabolite levels may strengthen this association.

Discriminant analysis of the Ullrich-Turner syndrome neurocognitive profile

Ullrich-Turner syndrome (UTS), or monosomy X, is a genetic disorder characterized by short stature, gonadal dysgenesis, and a particular neurocognitive profile of normally developed language abilities (particularly verbal IQ) and impaired visual-spatial and/or visual-perceptual abilities. The most frequently described profile in UTS includes difficulty with tasks involving memory and attention, decreased arithmetic skills, and impaired visual spatial processing. We used discriminant function analysis (DFA) to distinguish between the neurocognitive profiles of girls with UTS vs. controls matched for age, height, IQ, and socioeconomic status. DFA is a statistical method for deriving a linear function that optimally weights parameters to permit sensitive and specific differentiation among groups. We developed a modified discriminant function, based on seven cognitive test scores, that successfully discriminated between the UTS and control subjects with a sensitivity of 0.45 and a specificity of 0.97. To validate its performance, we applied the discriminant function to a small group of 45,X UTS subjects (n = 13) and control female subjects (n = 25), ages 7-16 years, who were not part of the previous analyses. The discriminant function (DF) identified 54% of these 13 UTS subjects as having the "UTS neurocognitive profile" and 92% of the 25 control subjects as not having the profile. We also compared the DF scores of UTS girls with various mosaic karyotypes and found that the group with 46,XX mosaicism had significantly higher scores (i.e., closer to normal controls) than the other two mosaic groups (t = 2.86, P < 0.005). The results of this study should be useful for genetic counseling and planning educational programs for girls with UTS.

Del (X)(p21.2) in a mother and two daughters with variable ovarian function

We report a family in which a woman with the mosaic karyotype 45,X/46,X,del(X)(p21.2) transmitted the deleted X chromosome to two daughters. The nature of the deletion was confirmed by fluorescent in situ hybridization (FISH). All three family members showed somatic Ullrich-Turner syndrome features, but only one daughter had ovarian failure. These observations have implications for the diagnosis of Ullrich-Turner syndrome and genotype/phenotype correlations of X chromosome deletions.

Absence of growth hormone effects on cognitive function in girls with Turner syndrome

Turner syndrome (TS) is a genetic disorder characterized by short stature, gonadal dysgenesis, and a particular neurocognitive profile of normally developed language abilities (particularly verbal IQ) and impaired visual-spatial and/or visual-perceptual abilities. We have followed a large sample of girls with Turner syndrome who were enrolled in a long-term, double-blind, placebo-controlled trial of the effects of growth hormone (GH) treatment on final adult height. This study provides a unique opportunity to prospectively evaluate the effects of GH treatment on neurocognitive function in this population of girls with Turner syndrome. The GH- and placebo-treated Turner syndrome subjects were well matched for age, treatment duration, race, karyotype, and socioeconomic status. Treatment (GH or placebo) durations ranged from 1-7 yr. Whether GH deficiency and/or treatment in childhood and adolescence influences cognitive outcome in short children or GH-children is controversial. The major result of this study was the absence of GH treatment effects on cognitive function in girls with Turner syndrome. Our findings are in agreement with most of the previous studies that found no apparent growth hormone treatment effects on cognitive function in growth-hormone deficient children. We conclude that this study does not support a role for growth hormone in influencing childhood brain development in girls with Turner syndrome. Their characteristic nonverbal neurocognitive deficits were not altered with GH treatment into early adolescence.

Adolescent self-esteem and locus of control: a longitudinal study of gender and age differences

The questions of whether self-esteem and locus of control change during the high school years, and whether gender differences exist in these variables were considered in this study. Participants consisted of 174 students who were ninth graders in 1989 and who were surveyed each spring for four years. Two-way ANOVAs were used to measure changes in self-esteem and locus of control over the four years as well as gender differences. A significant main effect for gender with lower self-esteem scores for girls was found. For locus of control, there was a significant main effect for grade and an interaction between grade and gender.

Developmental changes in motor function in girls with Turner syndrome

The Turner syndrome phenotype is characterized by a particular neurocognitive profile of normal verbal skills, impaired visuospatial and/or visuoperceptual abilities, and difficulty with motor function. We investigated motor function in non-estrogen-treated girls (ages 7-9 and 10-12 years) with Turner syndrome and age-matched female controls. Our goal was to delineate the differences in motor performance between girls with Turner syndrome (n = 78) and control girls (n = 145). Cognitive and motor tasks were administered, as well as nonspatial, repetitive motor tasks, and spatially mediated motor tasks. Questionnaires were also administered. Turner subjects performed less well than the controls on the motor tasks with the greatest spatial demands, particularly in the older age group (age 10-12.9 years). The older control group, unlike the older Turner syndrome group, had significantly increased speed on most of the motor tasks, suggesting a Turner syndrome-associated deficiency in motoric development. The superior performance of the dominant (right) versus the nondominant (left) hand was similar for the Turner syndrome and control groups. In general, the girls with Turner syndrome had evidence of a decreased sense of athletic ability and physical self-image. A likely explanation for motoric deficiency in the older Turner syndrome group relates to their gonadal dysgenesis and estrogen deficiency. In addition to the obvious physical benefits of estrogen replacement, estrogen treatment may have a positive impact on motor function; this will be the subject of future investigations.

Brain development, gender and IQ in children. A volumetric imaging study

Normal brain development during childhood is a complex and dynamic process for which detailed scientific information is lacking. MRI techniques, combined with methods for advanced image analysis, offer the potential to begin to construct a quantitative map of normal paediatric brain development in vivo. In this study we utilize volumetric analysis of high resolution brain images obtained from MRI to describe cerebral development and morphology in 85 normal children and adolescents ranging in age from 5 to 17 years. The results show that total cerebral volume is 10% larger in boys compared with girls. However, both boys and girls show little change in total cerebral volume after the age of 5 years. Increased cortical grey matter is the primary contributor to larger brain volume in boys, thus supporting the hypothesis that gender associated differences in brain size are related to differences in cortical neuronal density. Prominent, age-related changes in grey matter, white matter and CSF volumes are evident during childhood and appear to reflect ongoing maturation and remodelling of the CNS. Both boys and girls show a similar pattern of cerebral asymmetry; a rightward prominence of cortical and subcortical grey matter and a leftward prominence of CSF is observed. IQ is positively correlated with total cerebral volume in children, in particular, with the volume of cortical grey matter in the prefrontal region of the brain. Subcortical grey matter also contributes to the variance in IQ, although to a lesser extent than cortical grey volume. Quantitative knowledge of the developing human brain will play an increasingly greater role in improving sensitivity and specificity in the interpretation of brain abnormalities in patients within the clinical environment, as well as in groups of children with suspected brain dysfunction in the research setting.

Self-concept and behavior in adolescent girls with Turner syndrome: potential estrogen effects

Data on self-concept and behavior were gathered from 31 girls with Turner syndrome (TS) followed longitudinally between the ages of 12 and 16 and from 89 normal control girls recruited from public schools and assessed cross-sectionally. The two groups of girls were similar in age and racial composition. The girls with TS were treated with estrogen replacement therapy in increasing doses between the ages of 12 and 16 (100-400 ng/kg-day ethinyl estradiol). Their self-reported self-esteem and psychological well-being (Piers-Harris Self-Concept Scale) revealed significant improvement over time for most scales as well as the total score (P < 0.001). Parents reported improvement in problem behaviors, as reflected in the Child Behavior Checklist (CBCL) scales: Behavior Total, Externalizing Behavior, Aggressive Behavior, and Social Problems Behavior scales (all P < 0.001). Analysis of covariance comparing normal controls to the TS subjects revealed that at age 12 yr, TS and normal subjects differed significantly for the School Social Competency sub-scale and the Social Problems Behavior subscale (all P < 0.001). Girls with TS resembled the normal controls on all CBCL scales by ages 14-15 yr. Thus, we found improved self-concept both by self- and parental report in estrogen-treated girls with TS followed longitudinally through adolescence. An analogous correlation with age was not seen in the cross-sectional normal control sample. These findings support positive effects of estrogen on psychological well-being in girls with TS and underscores the need to initiate estrogen replacement therapy by ages 12-14 yr in this population.

Neurodevelopmental effects of X monosomy: a volumetric imaging study

Thirty girls with Turner syndrome (TuS) were compared with 30 individually age-matched controls on volumetric brain measures derived from magnetic resonance imaging and on measures of psychological functioning. As expected, girls with TuS performed more poorly on visual-spatial and intellectual measures relative to controls, and were rated by their parents as having more significant problems in attention and social behaviors. Although no group differences in overall cerebral or subcortical volumes were observed, the regional distribution of gray and white matter differed across groups in both right and left parietal regions. Differences in total tissue volume ratios were seen for both right and left parietal areas, but differences in individual gray and white matter ratios were seen exclusively in the right parietal regions. In general, girls with TuS had a smaller proportion of tissue (gray and white) within the right and left parietal regions, and a larger proportion of tissue within the right inferior parietal-occipital region relative to girls in the control group. These data suggest a potentially important role for X chromosome genes and/or sex steroids in the development and specialization of brain structure and function.

Activation of IL-2 receptor alpha-chain gene by individual members of the rel oncogene family in association with serum response factor

Expression of the IL-2R alpha gene is regulated by members of the c-Rel/NF-kappa B family of transcription factors binding to the kappa B site in the promoter. Previous work has not defined the role of individual members of the c-Rel family in the activation of the IL-2R alpha gene. Using the COS cell system, we were able to reconstitute the regulation of the IL-2R alpha promoter by expressing cloned Rel family members with serum response factor (SRF). We found that c-rel alone activated the IL-2R alpha promoter only weakly but worked with the p50 subunit of NF-kappa B (NFKB1) to give a higher level of expression. We showed that c-rel heterodimerizes with p50 and the amount of this heterodimer correlated with the level of IL-2R alpha gene expression. Our results provide evidence that c-rel/p50 heterodimers activate gene expression in the context of a cellular promoter. We show that c-rel or p65 can cooperate with SRF in the activation of this promoter and the transactivation by c-rel with SRF was enhanced by p50. Synergistic activation required both kappa B and CArG sites, and binding studies show that these adjacent sites can be occupied simultaneously. The transactivation observed with cloned transcription factors mimics the physiologic induction of the IL-2R alpha gene since multiple sequence elements cooperate to give gene activation. The data support the model that c-rel/p50 or p65 can cooperate with SRF to specifically target the expression of the IL-2R alpha gene in activated T cells.

Activation of IL-2 receptor alpha-chain gene by individual members of the rel oncogene family in association with serum response factor

Expression of the IL-2R alpha gene is regulated by members of the c-Rel/NF-kappa B family of transcription factors binding to the kappa B site in the promoter. Previous work has not defined the role of individual members of the c-Rel family in the activation of the IL-2R alpha gene. Using the COS cell system, we were able to reconstitute the regulation of the IL-2R alpha promoter by expressing cloned Rel family members with serum response factor (SRF). We found that c-rel alone activated the IL-2R alpha promoter only weakly but worked with the p50 subunit of NF-kappa B (NFKB1) to give a higher level of expression. We showed that c-rel heterodimerizes with p50 and the amount of this heterodimer correlated with the level of IL-2R alpha gene expression. Our results provide evidence that c-rel/p50 heterodimers activate gene expression in the context of a cellular promoter. We show that c-rel or p65 can cooperate with SRF in the activation of this promoter and the transactivation by c-rel with SRF was enhanced by p50. Synergistic activation required both kappa B and CArG sites, and binding studies show that these adjacent sites can be occupied simultaneously. The transactivation observed with cloned transcription factors mimics the physiologic induction of the IL-2R alpha gene since multiple sequence elements cooperate to give gene activation. The data support the model that c-rel/p50 or p65 can cooperate with SRF to specifically target the expression of the IL-2R alpha gene in activated T cells.

Ullrich-Turner syndrome: neurodevelopmental changes from childhood through adolescence

Our objective was to investigate whether the previously-described neurocognitive pattern in girls with Ullrich-Turner syndrome is found in childhood and adolescence; we used a prospective, controlled study of neurocognitive development in girls with Ullrich-Turner syndrome. The patients included 56 girls with Ullrich-Turner syndrome, and 100 normal age- and verbal IQ-matched female control subjects, whose ages ranged from 6-14 years. All girls with Ullrich-Turner syndrome and the normal control girls received a battery of neurocognitive tests designed to evaluate the following domains: general cognition, memory, academic achievement, language, visual-spatial/perceptual skills, visual-motor skills, attention, and affect recognition. Our results demonstrated consistent findings in Ullrich-Turner syndrome girls across the age range studied. In general, the Ullrich-Turner girls resembled control subjects in terms of verbal and language abilities. We found relatively depressed performance IQ and a significant verbal IQ-performance IQ difference. Significant differences were observed on examination of nonverbal abilities. The Ullrich-Turner girls performed more poorly than control girls on 1) tests of visual-motor skills including the Beery Test of Visual-Motor Integration, the Perceptual Organization Factor, and the Rey-Osterrieth Figures; 2) tests of visual-spatial skills, including the Motor-Free Visual Perception Test; 3) tests of attention, including the Freedom From Distractibility Factor; and 4) the Affective Prosody Affect Recognition Test. Ullrich-Turner subjects showed evidence of multifocal or diffuse right cerebral dysfunction and deficits generally involving nonverbal skills that may be due to X chromosome monosomy, gonadal dysgenesis, or both. Future studies will examine the role of estrogen replacement on cognitive function in Ullrich-Turner syndrome individuals.

Self-esteem and behavior in girls with Turner syndrome

Data on social competence, behavior, and self-esteem were gathered from a large sample of girls with Turner syndrome to determine whether psychological difficulties were associated with Turner syndrome. Subjects included 97 girls with Turner syndrome, 7 to 14 years of age, and 93 girls without Turner syndrome recruited from public schools. The two groups of girls were similar in age, verbal intelligence scores, and racial composition. The girls with Turner syndrome were found, based on both parental and self-report, to be more immature than the girls in the comparison group, with weaker social relationships, school performance, and self-esteem. A decline in self-esteem was also documented for the girls with Turner syndrome, but not the comparison group, as they moved into early adolescence. Although the findings support an increased risk for subtle behavioral problems among girls with Turner syndrome, in most cases the problems endorsed were not severe enough to suggest clinical impairment.

Growth hormone hypersecretion in a girl with McCune-Albright syndrome: comparison with controls and response to a dose of long-acting somatostatin analog

GH every 20 min for 24 h, insulin-like growth factor I (IGF-I), IGF-binding protein 3, and estradiol (E2) were measured in a 7.3-yr-old girl with precocious puberty due to McCune-Albright syndrome (MAS) who developed stigmata of early acromegaly and in 9 other MAS patients who had no signs of acromegaly. To determine whether the MAS patients had subtle abnormalities in GH secretion, a computerized pulse analysis program was used to compare the MAS data with those from 27 control girls with central precocious puberty who had a similar rate of bone age advance, E2, and body mass index. We found no differences in mean GH, GH pulse frequency, pulse height, or pulse area between MAS patients and controls except in patient 1, who had an elevated mean +/- SD GH compared with controls (15.4 +/- 2 vs. 4.8 +/- 2.3 micrograms/L; P < 0.01) and an elevated IGF-I (908 micrograms/L) and IGF-binding protein 3 (5.6 mg/L). None of the GH parameters correlated with body mass index, age, bone age, or E2 levels in either group. The serum GH in patient 1 fell to near-undetectable levels from 60-180 min after a 100-micrograms sc dose of long-acting somatostatin, confirming that this form of therapy can be effective in cases of GH hypersecretion due to MAS.

Lipid abnormalities in Turner syndrome

Turner syndrome is associated with insulin resistance, increased incidence of type II diabetes, and hypertension, all of which are cardiovascular risk factors. The purpose of this study was to evaluate the lipid profile of girls with untreated Turner syndrome, (aged 5 to 14 years; 68% 45,XO) and age-matched, normal girls. A total of 137 girls with Turner syndrome and 70 normal girls had lipid profile measurements, including cholesterol, high-density lipoprotein cholesterol, and triglycerides. Older girls with Turner syndrome (> 11.0 years) had increased cholesterol levels (p < 0.01), compared with control values (190 +/- 38 vs 165 +/- 26 mg/dl). Cholesterol levels were elevated in older subjects with Turner syndrome versus normal subjects, after adjustment for age, karyotype, and body mass index z score effects (p = 0.01). In the subjects with Turner syndrome but not the normal subjects, serum cholesterol values correlated with age, weight, and body mass index z score (p < 0.02). We conclude that adolescent girls with untreated Turner syndrome have significantly increased cholesterol levels, independent of age, body mass index z score, or karyotype, and that these precede any treatment with exogenous estrogen or growth hormone.

An evolutionarily conserved palindrome in the Drosophila Gld promoter directs tissue-specific expression

A conserved palindromic sequence (Gpal) in the promoter region of the Drosophila Gld directs expression of a heterologous reporter gene in transgenic flies to the anterior spiracular glands of third instar larvae and to the ejaculatory bulb of adult males. The Gld gene is normally expressed at high levels in the anterior spiracular glands but is not expressed in the ejaculatory bulb of Drosophila melanogaster. However, Gld promoters from other Drosophila species contain the Gpal element and express glucose dehydrogenase (GLD) in the adult male ejaculatory bulb. A gene fusion composed of the D. melanogaster Gld promoter and the lacZ gene is expressed in the anterior spiracular glands of transgenic larvae. Mutations of the Gpal sequence element in this gene fusion block expression of beta-galactosidase in the anterior spiracular gland. Together these experiments demonstrate that Gpal is necessary and sufficient for tissue-specific expression in the anterior spiracular glands. Based upon the tissue distribution and function of GLD, it is speculated that expression of GLD in the anterior spiracular glands represents the ancestral state and that GLD expression in other tissues arose as a fortuitous consequence of a shared combinatorial regulatory network.

A model of the Drosophila melanogaster glycerol-3-phosphate oxidase-encoding gene

We have sequenced the Drosophila melanogaster gene encoding the mitochondrial (mt) enzyme glycerol-3-phosphate oxidase (GPO; EC 1.1.99.5) that is involved in flight and alcohol metabolism. Available data suggests a simple model for this gene that includes four exons. Exon I contains a mt import signal, exon II, a transmembrane segment and an FAD-binding site, and exon IV, an iron-sulfur centre.

EVA design: lessons learned

Extravehicular Activities (EVAs) are very demanding and specialized space flight activities. There are many aspects to consider in the design of hardware, tools, and procedures to be used on an EVA mission. To help minimize costs and optimize the EVA productivity, experience shows that astronauts should become involved early in the design process.

Correlated evolution of the cis-acting regulatory elements and developmental expression of the Drosophila Gld gene in seven species from the subgroup melanogaster

The tissue-specific expression patterns of glucose dehydrogenase (GLD) exhibit a high degree of interspecific variation in the adult reproductive tract among the species in the genus Drosophila. We chose to focus on the evolution of GLD expression and the evolution of the Gld promoter in seven closely related species in the melanogaster subgroup as a means of elucidating the relationship of changes in cis-acting regulatory elements in the Gld promoter region with changes in tissue-specific expression. Although little variation in tissue-specific patterns of GLD was found in nonreproductive tissues during development, a surprisingly high level of variation was observed in the expression of GLD in both developing and mature reproductive organs. In some cases this variation is correlated with changes in sequence elements in the Gld promoter which were previously shown to direct tissue-specific expression in the reproductive tract. In particular D. teissieri adult males do not express GLD in their ejaculatory ducts, atypical of the melanogaster subgroup species. The Gld promoter region of D. teissieri specifically lacks all three of the TTAGA regulatory elements present in D. melanogaster. The TTAGA elements were previously shown to direct reporter gene expression to the ejaculatory duct. Together these data suggest the absence or presence of the TTAGA elements may be responsible for variation in the absence or presence of GLD in the ejaculatory duct among species.

Altered brain development in Turner's syndrome: an event-related potential study

We compared event-related brain potentials (ERPs) and reaction time (RT) measures from untreated young (prepubertal and peripubertal; ages 9 to 14) and old (postpubertal; ages 15 to 20) Turner's syndrome (TS) subjects with those from normal age-matched controls. Comparisons among groups permitted the assessment of the relative roles of congenital and maturational brain alterations as possible bases of the cognitive deficits in TS. All subjects were presented with series of auditory stimuli, and they either counted one of the two stimuli or made rapid discriminative button presses to both. The results indicated that, whereas the ERPs in young TS females were essentially the same as those in their age-matched controls, the ERPs in old TS females more closely resembled those in both young groups than those in their age-matched controls. Specifically, a late (400 to 900 msec) frontal negative slow wave (Nc) in the old TS subjects failed to show the normal maturational course in which the amplitude and duration of this component steadily decreases with age. Except for slightly greater amounts of N1 amplitude in the young TS group, the latencies, amplitudes, and scalp distributions of the other ERP components (N1, P2, N2, P300) were all the same at all ages in the TS subjects and their controls. Behaviorally, both TS groups had longer RTs than their controls but, consistent with the ERP results, they did not make more errors.(ABSTRACT TRUNCATED AT 250 WORDS)