Stabilization of p53 by p14ARF without relocation of MDM2 to the nucleolus.

The alternative product of the human INK4a/ARF locus, p14ARF, has the potential to act as a tumour suppressor by binding to and inhibiting the p53 antagonist MDM2. Current models propose that ARF function depends on its ability to sequester MDM2 in the nucleolus. Here we describe situations in which stabilization of MDM2 and p53 occur without relocalization of endogenous MDM2 from the nucleoplasm. Conversely, forms of ARF that do not accumulate in the nucleolus retain the capacity to stabilize MDM2 and p53. We therefore propose that nucleolar localization is not essential for ARF function but may enhance the availability of ARF to inhibit MDM2.

Solar differential rotation and oblateness.

An investigation of the time development of differential rotation produced by the solar wind torque indicates that the sun has a rapidly rotating core.

Comprehensive analysis of CDKN2A (p16INK4A/p14ARF) and CDKN2B genes in 53 melanoma index cases considered to be at heightened risk of melanoma.

OBJECTIVE: Comprehensive analysis of the 9p21 locus including the CDKN2A, ARF, and CDKN2B genes in 53 individuals from melanoma index cases considered to be at heightened risk of melanoma. METHODS AND RESULTS: Using a combination of DNA sequencing, gene copy number by real time quantitative PCR, linkage analysis, and transcript analysis in haploid somatic cell hybrids, we found no evidence for germline alteration in either coding or non-coding domains of CDKN2A and CDKN2B. However, we identified a p14ARF exon 1beta missense germline mutation (G16D) in a melanoma-neural system tumour syndrome (CMM+NST) family and a 8474 bp germline deletion from 196 bp upstream of p14ARF exon 1beta initiation codon to 11233 bp upstream of exon 1alpha of p16(INK4A) in a family with five melanoma cases. For three out of 10 families with at least three melanoma cases, the disease gene was unlinked to the 9p21 region, while linkage analysis was not fully conclusive for seven families. CONCLUSIONS: These data reinforce the hypothesis that ARF is a melanoma susceptibility gene and suggest that germline deletions specifically affecting p14ARF may not be solely responsible for NST susceptibility. Predisposition to CMM+NST could either be due to complete disruption of the CDKN2A locus or be the result of more complex genetic inheritance. In addition, the absence of any genetic alteration in 50 melanoma prone families or patients suggests the presence of additional tumour suppressor genes possibly in the 9p21 region, and on other chromosomes.

Numerical simulations of the impact of the 20 March 2015 eclipse on UK weather.

Short lead-time forecasts using the operational United Kingdom variable-resolution (UKV) configuration of the Met Office's numerical weather prediction model, with horizontal grid-length 1.5 km over the UK, with and without a representation of the 20 March 2015 eclipse, have been used to simulate the impact of the eclipse on UK weather. The major impact was surface-driven through changes to surface heat and moisture fluxes that changed the boundary-layer development. In cloud-free areas, the nocturnal stable boundary layer persisted or quickly re-established during the eclipse. Surface temperatures were reduced by 7-8°C, near-surface air temperature by 1-3°C, and near-surface winds were backed, typically by 20°. Impacts on wind speed were small and variable, and would have been very difficult to detect. Smaller impacts occurred beneath cloud. However, the impact was enhanced because most of the incoming radiation that reached the surface was driving surface sensible heat flux rather than moisture flux, and the near-surface air temperature impact (0.5-1°C) agrees reasonably well with observations. The modelled impact of the eclipse was substantially reduced in urban areas due to their large thermal inertia. Experience from other assessments of the model suggests that this lack of response may be exaggerated. Surface impacts propagated upwards and downstream with time, resulting in a complex pattern of response, though generally near-surface temperature differences persisted for many hours after the eclipse. The impact on atmospheric pressure fields was insufficient to account for any significant perturbations to the wind field when compared with the direct impacts of surface stress and boundary-layer mixing.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

Developmental expression of the homeobox protein Distal-less 3 and its relationship to progesterone production in mouse placenta.

Distal-less 3 (Dlx3) is a homeobox factor that functions as a placental-specific transcriptional regulator. Dlx3 null mice (-/-) have compromised placental development and do not survive in utero past embryonic day (E) 9.5. The current studies were undertaken to examine the expression of Dlx3 in mouse placenta during gestation, and to determine whether Dlx3 was involved in placental progesterone production. Dlx3 was not detectable at E8.5 but was detected in E9.5 placenta with continuing but diminished expression through E15.5. Dlx3 immuno-localization was restricted to the labyrinth, was nuclear and was found in cytokeratin-positive cells. Previous studies in choriocarcinoma cell lines support the conclusion that Dlx3 is required for expression of 3'-hydroxysteroid dehydrogenase VI (3betaHSD VI), an obligate enzyme in the production of progesterone by trophoblast giant cells. In a rat trophoblast stem cell line (Rcho-1), Dlx3 expression was non-detectable in Rcho-1 cells induced to differ-entiate using mitogen withdrawal. In vitro progesterone production in placental cultures and 3betaHSD VI mRNA from Dlx3 (+/+), (+/-) and (-/-) mice were equivalent. In situ hybridization for 3betaHSD VI revealed mRNA expression restricted to trophoblast giants cells with no detectable expression in the labyrinth suggesting that Dlx3 and 3betaHSD VI were not colocalized within the placenta. These studies support the conclusion that Dlx3 protein expression is restricted to the labyrinth region of the murine placenta into late gestation and that Dlx3 does not appear to be expressed in trophoblast giant cells. Further, loss of Dlx3 was not correlated with synthesis of progesterone from E9.5 mouse placentas.

Comparison of pulsatile luteinizing hormone secretion between prepubertal children and young adults: evidence for a mass/amplitude-dependent difference without gender or day/night contrasts.

The assessment of pulsatile GnRH activity in children has become possible since the introduction of the sensitive third generation immunochemiluminescent assays, permitting detection of previously unmeasurable levels of LH and FSH. Despite this, however, studies differ with regard to pulse frequency and the presence of a diurnal variation in LH secretion in clinically prepubertal children. Discrepancies may reflect the limitations of relatively long intersampling intervals, less sensitive LH assays such as RIAs, and the use of algorithms to analyze pulsatile LH secretion, which do not account for endogenous production rates and metabolic clearance. To address this, we studied LH secretion in 10 prepubertal children (4 boys and 6 girls, age 8.5-10.8 y) and 12 young adults (7 men and 5 women in the early follicular phase, age 18.6-32.8 y). Blood was sampled every 5 min from 2000 h to 0200 h (nighttime) and from 0800 h to 1400 h (daytime) for LH determination, using an immunochemiluminescent assay. Deconvolution analysis revealed no difference between daytime and nighttime LH secretion, including LH secretory amplitude and pulse frequency, within any of the 4 groups, permitting pooling of the data from the 2 sampling intervals for analysis. In addition, there was no difference in LH secretion or half-life between genders. Comparison of pulsatile LH secretion between children and adults revealed a marked increase in the mass and amplitude of LH secreted per burst. LH secretory burst mass rose 9.5-fold in females, increasing the mean LH concentration by nearly 13-fold and the production rate by nearly 9-fold. The trend in males was similar although less remarkable, with a 4.2-fold rise in LH secretory burst mass from childhood to adulthood. No differences in pulse frequency, interburst interval, half-life, or approximate entropy were found between prepubertal children and adults. We conclude that the maturational change in LH secretion occurs via a highly specific mass/amplitude-dependent mechanism without significant gender or day/night differences.

Alterations in growth and body composition during puberty: III. Influence of maturation, gender, body composition, fat distribution, aerobic fitness, and energy expenditure on nocturnal growth hormone release.

We examined the relationships among gender, sexual maturation, four-compartment model estimates of body composition, body fat distribution (magnetic resonance imaging for abdominal visceral fat and anthropometrics), aerobic fitness, basal and total energy expenditure, and overnight GH release in an ultrasensitive chemiluminescence assay in healthy prepubertal and pubertal boys (n = 18 and 11, respectively) and girls (n = 12 and 18, respectively). Blood samples were withdrawn every 10 min from 1800-0600 h to determine the area under the serum GH-time curve (AUC), sum of the GH peak heights (sigma GH peak heights), and the mean nadir GH concentration. GH release was greater in the pubertal than prepubertal subjects due to an increase in sigma GH peak heights (43.8 +/- 3.6 vs. 24.1 +/- 3.5 ng.mL-1, P = 0.0002) and mean nadir (1.7 +/- 0.2 vs. 0.7 +/- 0.2 ng.mL-1, P = 0.0002), but not peak number (4.3 +/- 0.2 vs. 4.5 +/- 0.2). The girls had a greater sigma GH peak heights (39.0 +/- 3.5 vs. 28.8 +/- 3.6 ng.mL-1, P = 0.05) and mean nadir concentration (1.4 +/- 0.2 vs. 0.9 +/- 0.2 ng.mL-1, P = 0.05) than the boys. Significant inverse relationships existed between sigma GH peak heights (r = -0.35, P = 0.06) or mean nadir (r = -0.39, P = 0.04) and four-compartment percent body fat for all boys but not for all girls or when combining all subjects. For all girls, significant inverse relationships existed between sigma GH peak heights (r = -0.39, P = 0.03) or mean nadir (r = -0.37, P = 0.04) and waist/hip ratio. Similar inverse relationships in all boys or all subjects were not significant. Forward stepwise regression analysis determined that bone age (i.e. maturation, primary factor) and gender were the significant predictors of AUC, sigma GH peak heights, and mean nadir. The influence of maturation reflects rising sex steroid concentrations, and the gender differences appear to be because of differences in estradiol concentrations rather than to body composition or body fat distribution.

The gene organisation of the human beta 2 integrin subunit (CD18).

We have studied the gene of the human beta 2 integrin subunit (CD18) and found it to be organised into 16 exons spanning a region of about 40 kb. All exon/intron boundaries conform to the GT/AG splicing consensus. The exons coding for the cysteine-rich region, which has been postulated to consist of 3 or 4 repeating elements, are not organised correspondingly. Transcription of the gene initiates from multiple sites which may be due to the absence of an upstream TATA box. The polyadenylation site is also heterogeneous. Five different sites were identified over a stretch of 10 bases.

Growth and pubertal development in children and adolescents: effects of diet and physical activity.

The longitudinal growth of an individual child is a dynamic statement of the general health of that child. Measurements should be performed often and accurately to detect alterations from physiologic growth. Although any single point on the growth chart is not very informative, when several growth points are plotted over time, it should become apparent whether that individual's growth is average, a variant of the norm, or pathologic. Somatic growth and maturation are influenced by several factors that act independently or in concert to modify an individual's genetic growth potential. Linear growth within the first 2 y of life generally decelerates but then remains relatively constant throughout childhood until the onset of the pubertal growth spurt. Because of the wide variation among individuals in the timing of the pubertal growth spurt, there is a wide range of physiologic variations in normal growth. Nutritional status and heavy exercise training are only 2 of the major influences on the linear growth of children. In the United States, nutritional deficits result from self-induced restriction of energy intake. That single factor, added to the marked energy expenditure of training and competition for some sports, and in concert with the self-selection of certain body types, makes it difficult to identify the individual factors responsible for the slow linear growth of some adolescent athletes, for example, those who partake in gymnastics, dance, or wrestling.

Alterations in growth and body composition during puberty. IV. Energy intake estimated by the youth-adolescent food-frequency questionnaire: validation by the doubly labeled water method.

BACKGROUND: Estimates of energy intake are required for an understanding of growth and disease; however, few methods of energy intake in children have been validated. OBJECTIVE: Our objective was to validate energy intake estimated by the Youth-Adolescent Food-Frequency Questionnaire (YAQ) against the criterion total energy expenditure (TEE) by doubly labeled water (DLW). DESIGN: Twenty-three boys and 27 girls (8.6-16.2 y of age) completed the YAQ and TEE measurements in 1 y. RESULTS: Energy intake by the YAQ (10. 03 +/- 3.12 MJ) and energy expenditure by DLW (9.84 +/- 1.79 MJ) were similar (P: = 0.91) with large lower (-6.30 MJ) and upper (6.67 MJ) +/-2 SD limits of agreement. When within-subject CVs of repeated measures of the DLW and YAQ methods were used, 25 of the 50 subjects were deemed to have misreported their energy intake. The discrepancy in energy intake (YAQ - TEE) was related to body weight (r = -0.25, P: = 0.077) and percentage body fat (r = -0.24, P: = 0.09) but not to age (r = -0.07, P: = 0.63) or the time between measures. From logistic regression, fatter boys were more likely to underreport energy intake than were fatter girls. CONCLUSION: The YAQ provides an accurate estimation of mean energy intake for a group but not for an individual.

Growth hormones and sex steroid interactions at puberty.

Puberty is a period of dynamic changes mediated by GH and the gonadal steroid hormones. Although these substances exert important independent effects, their interaction is vital to normal pubertal growth and development. This is supported by observations of blunted growth and diminished levels of GH and IGF-1 during adolescence in individuals with panhypopituitarism in whom adequate replacement with both hormones had not been achieved. The independent roles of androgens and estrogens in mediating the rise in GH secretion at puberty have been studied in individuals with complete androgen insensitivity and through the administration of nonaromatizable androgens and the use of selective androgen- or estrogen-receptor blockade. The preponderance of evidence from studies of nonaromatizable (pure) androgens suggests that GH secretion is not enhanced as it is under the influence of testosterone. In addition, studies have shown increased GH secretion following androgen-receptor blockade and diminished GH release after estrogen-receptor blockade. Together these studies suggest a facilitory role of estrogen receptor-mediated processes on GH secretion and IGF-1 production. If androgens influence the GH/IGF-1 axis, it is most likely by an inhibitory mechanism. Observations of delayed skeletal maturation and deficient bone mineralization in individuals with estrogen receptor defects or mutations of the aromatase gene demonstrate the essential role of estrogen in promoting normal bone maturation, the accrual and maintenance of BMD, and control of the rate of bone turnover.

Comparison of mass spectrometric techniques for generating molecular weight information on a class of ethoxylated oligomers.

The results of fast atom bombardment (FAB), time-of-flight secondary ion mass spectrometry (ToF-SIMS), matrix-assisted laser desorption/ionization (MALD/I), electrospray ionization (ESI), and field desorption (FD) analyses of ethoxylated oligomers of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (Surfynol(®) 104) were compared.Each of these desorption mass spectrometry (MS) techniques can produce spectra of unfragmented cationized oligomers. From the observed ion series we calculate average molecular weight information. We have compared the results of mass spectrometric analyses of a series of ethoxylated Surfynol surfactants. Our data indicate that FAB, ToF-SIMS, MALDI/I, and ESI produce similar results for the lower molecular weight species, but that as the average molecular weight increases FAB and SIMS produce slightly lower results than MALD/I and FD. This could be due to increased fragmentation. ESI produced a result similar to FAB and SIMS for the highest average molecular weight material. Further experiments compare the mass spectral results with gas chromatographic quantitative data. Although gas chromatography is not expected to accurately analyze the higher mass oligomers, we observe significant differences in intensities of the short-chain oligomers (especially the 0- and 1-mers) when compared to the desorption mass spectrometer results. These differences may reflect poor cationization efficiency for very short oligomer chains in the mass spectrometric analyses.

Noncomparative, open label, multicenter trial of cefixime for treatment of bacterial pharyngitis, cystitis and pneumonia in pediatric patients.

Cefixime, a new third generation oral cephalosporin antibiotic, was evaluated for safety and efficacy in the treatment of 206 children with acute bacterial pharyngitis, cystitis or pneumonia. Each patient had a throat, urine or sputum culture before therapy and was treated with a 10- to 14-day course of cefixime, 8 mg/kg once daily. Bacterial pathogens were isolated in 167 of 206 (81.1%). Streptococcus pyogenes (73.7% of isolates) and Escherichia coli (9.6%) were the most common Gram-positive and Gram-negative organisms, respectively. All patients were evaluable for safety, and 109 (52.9%) with pharyngitis (96) or cystitis (13) were evaluable for efficacy. Clinical failure occurred in 2 of 109 (1.8%) patients, both with pharyngitis; bacteriologic failure occurred in 1 patient with pharyngitis and 1 with cystitis. Five patients with pneumonia caused by possible pathogens also improved while taking cefixime. Drug-related adverse side effects occurred in 50 of 206 patients (24.3%); these were generally mild and led to discontinuing the antibiotic in only 4 patients (1.9%). The most common were diarrhea or loose stools (33 of 206, or 16%). Results of this study suggest that cefixime given once daily to children is safe and effective in the treatment of streptococcal pharyngitis and bacterial cystitis.

Alterations in growth and body composition during puberty. I. Comparing multicompartment body composition models.

A four-compartment (4C) model of body composition was used as a criterion to determine the accuracy of three-compartment (3C) and two-compartment (2C) models to estimate percent body fat (%BF) in prepubertal and pubertal boys (genital I & II, n = 17; genital III & IV, n = 7) and girls (breast I & II, n = 8; breast III & IV, n = 15). The 3C water-density (3C-H2O) and 3C mineral-density models, dual-energy X-ray absorptiometry, the Lohman age-adjusted equations, the Slaughter et al. skinfold equations, and the Houtkooper et al. and Boileau bioelectrical impedance equations were evaluated. Agreement with the 4C model increased with the number of compartments (i.e., body water, bone mineral) measured. Except for the 3C-H2O model, the limits of agreement were large and did not perform well for individuals. The mean %BF by dual-energy X-ray absorptiometry (23.6%) was greater than that of the criterion 4C method (21.7%). For the field methods, the Slaughter et al. skinfold equations performed better than did the Houtkooper et al. and Boileau bioimpedance equations. The hydration of the fat-free mass decreased (genital I & II = 75.7%, genital III & IV = 74.8%, breast I & II = 75.5%, breast III & IV = 74.4%) and the mineral content increased (genital I & II = 4.9%, genital III & IV = 5.0%, breast I & II = 5.1%, breast III & IV = 5.7%) with maturation. The density of the fat-free mass also increased (genital I & II = 1.084 g/ml, genital III & IV = 1.087 g/ml, breast I & II = 1.086 g/ml, breast III & IV = 1.091 g/ml) with maturation. All of the models reduced the %BF overprediction of the Siri 2C model, but only the 4C and 3C-H2O models should be used as criterion methods for body composition validation in children and adolescents.

What residents are not learning: observations in an NICU.

In light of the November 1999 report of the Institute of Medicine on medical errors as a leading cause of death and injury, and the July 2000 report of the Accreditation Council for Graduate Medical Education citing violations of work-hour standards for residents and interns, there is a clear need for substantial changes in residency training. The author, a clinical bioethicist, uses his extended observations at a neonatal intensive care unit (NICU) of a major U.S. teaching hospital to outline specific concerns about residents' and interns' training, medical and otherwise, that create unnecessary hazards and other difficulties in the medical care of children. These concerns-which arise from constructive criticisms he makes of specific NICU procedures, methods, approaches, and policies-apply directly to training residents in several areas of medicine and more generally to all residents' training, and echo many of the issues stated in the reports mentioned above. The author maintains that a well-rounded medical education, fostering not only clinical skills but others (e.g., skills in teaching; in communication; in collaborating with nurses, social workers, and others; in working with families; in showing compassion; in dealing with confidentiality issues; in using common sense; in being the patient's advocate), is crucial for producing well-rounded physicians. He emphasizes that in order for such a well-rounded education to occur, the residency program-which in many cases means the attending physicians-must teach and model these varied skills and attitudes to their trainees.

The ethics of alternative medicine therapies.

It is estimated that 42% of the American public is using some form of alternative medicine, which reflects the changing needs and values in our society. Unfortunately, Western medicine has failed to see alternative medicine as complementary and integrative with conventional medicine. This is due to the fact that there is very little scientific data available regarding the safety, efficacy, optimal dosage and side-effects or interactions of these alternative medicine therapies. Many physicians dismiss a patient's questions concerning alternative medicine because the physician believes it is "quackery," without any proof to support this claim. This violates the patient's right to full disclosure of all possible treatment options and encourages patients to use these therapies without their physician's knowledge. As a result, it is estimated that 46% of those using alternative medicine do so without the supervision of their primary care physicians or alternative medicine practitioners. At the present time there is no regulatory process to ensure the safety and efficacy of these alternative medicine therapies. Manufacturers do not have to prove that their product works, but they must ensure that their product is not harmful. The combination of failure to inform physicians of usage and the possibility of adverse reactions with prescription drugs is placing the lives of many Americans in jeopardy. Ethically, consumers have the right to use alternative medicine therapies as a matter of autonomy, but they also have the duty not to harm themselves. To ensure their safety, alternative medicine therapies must be evaluated in regards to safety and efficacy so that they can be integrated into conventional medicine. The Federal Drug Administration has the ethical responsibility to take the lead in this area. To protect the common good, there is a need to know not only what alternative medicine can do for us but what it can do to us.

The ethics of medical marijuana: government restrictions vs. medical necessity.

Marijuana is listed by the Drug Enforcement Agency (DEA) as an illegal Schedule I drug which has no currently accepted medical use. However, on March 17, 1999, 11 independent scientists appointed by the Institute of Medicine reported that medical marijuana was effective in controlling some forms of pain, alleviating nausea and vomiting due to chemotherapy, treating wasting due to AIDS, and combating muscle spasms associated with multiple sclerosis. There was also no evidence that using marijuana would increase illicit drug use or that it was a "gateway" drug. Despite this evidence the DEA refuses to reclassify marijuana as a Schedule II drug, which would allow physicians to prescribe unadulterated and standardized forms of marijuana. After reviewing the pertinent scientific data and applying the principle of double effect, there is a proportionate reason for allowing physicians to prescribe marijuana. Seriously ill patients have the right to effective therapies. To deny patients access to such a therapy is to deny them dignity and respect as persons.

Cost-effectiveness of preimmunization hepatitis B screening in high-risk adolescents.

OBJECTIVE: The goals of this study were to estimate seroprevalence of prior hepatitis B infection among high-risk adolescents and to determine the cost-effectiveness of prevaccination immunity screening. METHODS: The authors computed a "break-even" seroprevalence level calculated from current vaccine and administration costs. They then conducted a seroprevalence study of hepatitis B core antibody using sera previously submitted for syphilis serology from four-hundred adolescent and adult clients of sexually transmitted disease clinics. Finally, the authors compared age group-specific seroprevalence rates to the computed break-even seroprevalence. RESULTS: Levels of prior hepatitis B infection for all age groups were lower than the break-even seroprevalence standard from which cost-effectiveness was calculated. CONCLUSIONS: From the findings of this study, the authors concluded that routine preimmunization screening for prior hepatitis B infection would not be cost-effective for this population.

Nonclassic 11 beta-hydroxylase deficiency: report of two patients and review.

Congenital adrenal hyperplasia (CAH) is well recognized as a disorder which can result in virilization of females, accelerated skeletal maturation and resultant adult short stature in both genders, and, in certain varieties, life-threatening adrenal crisis. Among the enzymatic defects resulting in CAH, nonclassic or partial 11 beta-hydroxylase deficiency is a relatively uncommon etiology. However, the subtlety with which it can present and the difficulties associated with its diagnosis can delay its identification and result in a significant reduction in adult stature. This paper describes the presentation and evaluation of two children with partial 11 beta-hydroxylase deficiency, discusses its pathogenesis, and compares the disorder with the more common varieties of congenital adrenal hyperplasia.

Apparent self-limited androgen excess in a 4 year-old male.

We describe a 4 year-old male with significant virilization, but no source of endogenous or exogenous androgen excess after extensive testing. Evaluation of androgen receptor function, 5 alpha-reductase activity, steroid hormone secretion patterns, and androgen metabolite concentrations were also within the normal range. Over a 10 month period there was spontaneous resolution of the physical and behavioral signs of androgenization. We postulate a self-limited process of androgen production which may represent a yet undefined pattern of sexual precocity in males.