High-dose corticosteroids in patients with the adult respiratory distress syndrome

Corticosteroids are widely used as therapy for the adult respiratory distress syndrome (ARDS) without proof of efficacy. We conducted a prospective, randomized, double-blind, placebo-controlled trial of methylprednisolone therapy in 99 patients with refractory hypoxemia, diffuse bilateral infiltrates on chest radiography and absence of congestive heart failure documented by pulmonary-artery catheterization. The causes of ARDS included sepsis (27 percent), aspiration pneumonia (18 percent), pancreatitis (4 percent), shock (2 percent), fat emboli (1 percent), and miscellaneous causes or more than one cause (42 percent). Fifty patients received methylprednisolone (30 mg per kilogram of body weight every six hours for 24 hours), and 49 received placebo according to the same schedule. Serial measurements were made of pulmonary shunting, the ratio of partial pressure of arterial oxygen to partial pressure of alveolar oxygen, the chest radiograph severity score, total thoracic compliance, and pulmonary-artery pressure. We observed no statistical differences between groups in these characteristics upon entry or during the five days after entry. Forty-five days after entry there were no differences between the methylprednisolone and placebo groups in mortality (respectively, 30 of 50 [60 percent; 95 percent confidence interval, 46 to 74] and 31 of 49 [63 percent; 95 percent confidence interval, 49 to 77]; P = 0.74) or in the reversal of ARDS (18 of 50 [36 percent] vs. 19 of 49 [39 percent]; P = 0.77). However, the relatively wide confidence intervals in the mortality data make it impossible to exclude a small effect of treatment. Infectious complications were similar in the methylprednisolone group (8 of 50 [16 percent]) and the placebo group (5 of 49 [10 percent]; P = 0.60). Our data suggest that in patients with established ARDS due to sepsis, aspiration, or a mixed cause, high-dose methylprednisolone does not affect outcome.

Identifying risk for obesity in early childhood

OBJECTIVES

Our aim with this study was to assist clinicians by estimating the predictive value of earlier levels of BMI status on later risk of overweight and obesity during the middle childhood and early adolescent years.

METHODS

We present growth data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, a longitudinal sample of 1042 healthy US children in 10 locations. Born in 1991, their growth reflects the secular trend of increasing overweight/obesity in the population. Height and weight of participating children in the study were measured at 7 time points. We examined odds ratios for overweight and obesity at age 12 years comparing the frequency with which children did versus did not reach specific BMI percentiles in the preschool- and elementary-age periods. To explore the question of whether and when earlier BMI was predictive of weight status at age 12 years, we used logistic regression to obtain the predicted probabilities of being overweight or obese (BMI > or = 85%) at 12 years old on the basis of earlier BMI.

RESULTS

Persistence of obesity is apparent for both the preschool and elementary school period. Children who were ever overweight (> 85th percentile), that is, > or = 1 time at ages 24, 36, or 54 months during the preschool period were > 5 times as likely to be overweight at age 12 years than those who were below the 85th percentile for BMI at all 3 of the preschool ages. During the elementary school period, ages 7, 9, and 11 years, the more times a child was overweight, the greater the odds of being overweight at age 12 years relative to a child who was never overweight. Sixty percent of children who were overweight at any time during the preschool period and 80% of children who were overweight at any time during the elementary period were overweight at age 12 years. Follow-up calculations showed that 2 in 5 children whose BMIs were > or = 50th percentile by age 3 years were overweight at age 12 years. No children who were < 50th percentile for BMI at all points during elementary school were overweight at age 12 years. Children who have higher range BMIs earlier, but not at the 85th percentile, are also more likely to be overweight at age 12 years. Even at time points before and including age 9 years, children whose BMIs are between the 75th and 85th percentile have an approximately 40% to 50% chance of being overweight at age 12 years. Children at 54 months old whose BMIs are between the 50th and 75th percentile are 4 times more likely to be overweight at age 12 years than their contemporaries who are < 50th percentile, and those whose BMIs are between the 75th and 85th percentile are > 6 times more likely to be overweight at age 12 years than those < 50th percentile.

CONCLUSIONS

The data from this study indicate that children with BMIs > 85th percentile, as well as with BMIs in the high reference range are more likely than children whose BMI is < 50th percentile to continue to gain weight and reach overweight status by adolescence. Pediatricians can be confident in counseling parents to begin to address the at-risk child's eating and activity patterns rather than delaying in hopes that overweight and the patterns that support it will resolve themselves in due course. Identifying children at risk for adolescent obesity provides physicians with an opportunity for earlier intervention with the goal of limiting the progression of abnormal weight gain that results in the development of obesity-related morbidity.

Cadherin function is required for axon outgrowth in retinal ganglion cells in vivo

The cell-cell adhesion molecule N-cadherin strongly promotes neurite outgrowth in cultured retinal neurons. To test whether cadherins regulate process outgrowth in retinal neurons in vivo, we have blocked cadherin function in single cells by expression of a dominant negative N-cadherin mutant. We report that when cadherin function is inhibited, axon and dendrite outgrowth are severely impaired, particularly in retinal ganglion cells. Laminar migration and cell type specification, by contrast, appear unaffected. Further, expression of the catenin-binding domain of N-cadherin, which blocks cadherin-mediated adhesion in early embryos, does not affect axon outgrowth, suggesting that outgrowth and adhesion are mediated by distinct regions of the cytoplasmic domain. These findings indicate that cadherins play an essential role in the initiation and extension of axons from retinal ganglion cells in vivo.

Comparative trial in infants of four conjugate Haemophilus influenzae type b vaccines

We performed a double-blind, randomized trial to compare the immunogenicity and reactogenicity of four conjugate Haemophilus influenzae type b vaccines given to infants 2, 4, and 6 months of age. Adverse reactions attributable to the vaccines were few and minor. The rates of systemic reactions did not differ among the various vaccines and were similar to those seen among children receiving conventional diphtheria-tetanus-pertussis vaccine. However, the four conjugate H. influenzae type b vaccines differed markedly in ability to stimulate antibody production. Mean antibody levels after three injections of polyribosylribitol phosphate conjugated with mutant diphtheria protein (PRP-CRM) or polyribosylribitol phosphate conjugated with tetanus toxoid (PRP-T) were 3.08 micrograms/ml and 3.64 micrograms/ml, respectively, significantly higher than those after the use of polyribosylribitol phosphate conjugated with outer-membrane protein of Neisseria meningitidis (PRP-OMP) (1.14 micrograms/ml) or polyribosylribitol phosphate conjugated with diphtheria toxoid (PRP-D) (0.28 microgram/ml). Only PRP-OMP produced a clinically pertinent elevation in antibody level after two injections (0.84 microgram/ml); the third injection of PRP-OMP produced a modest but statistically significant further elevation in mean antibody level (1.14 micrograms/ml). Only 29% of infants receiving PRP-D had antibody levels of 1 micrograms/ml, compared with 55%, 75%, and 83% of those receiving PRP-OMP, PRP-CRM, and PRP-T, respectively. We conclude that all four vaccines are safe and that all but PRP-D appear appropriate for use in a primary immunization series during infancy. The unique serologic response to PRP-OMP offers both advantages and disadvantages in comparison with PRP-CRM and PRP-T.

Cardiovascular effects of morphine and opioid peptides following intracisternal administration in chloralose-anesthetized rats

Beta-Endorphin (0.9--2.0 nmol), morphine (11--250 nmol) and D-ala2-met-enkephalinamide (17--33 nmol) administered intracisternally produced preferential vasodepressor responses and bradycardia. Leu- (1.8--180 nmol), met-enkephalin (17--520 nmol) and alpha-endorphin (5.7--57 nmol) administered in the same way produced preferential vasopressor effects and the latter two peptides also produced bradycardia. Results obtained with naloxone (300 nmol) given intracisternally indicate that the pressor and depressor actions as well as the bradycardia are mediated through opiate receptors. The results indicate that opioid peptides may be involved in central cardiovascular control.

Unaltered susceptibility to BSE in transgenic mice expressing human prion protein

Prion diseases are transmissible neurodegenerative conditions of humans and animals. Prions consist principally of a post-translationally modified form of prion protein (PrP), PrP(Sc), which is partly protease resistant. Transmission of prion diseases between species is limited by a 'species barrier' determined in part by the degree of sequence homology between host PrP and inoculated PrP(Sc) (ref.3) and by prion strain type. The epidemic of bovine spongiform encephalopathy (BSE) in the United Kingdom and other countries has led to concerns that transmission to humans may occur by dietary exposure. BSE appears to be caused by a single strain, distinct from those of natural or experimental scrapie, which is also seen in the new prion diseases of cats and ruminants that have presumably arisen from dietary BSE exposure. Here we show that transgenic mice expressing human PrP in addition to mouse PrP can generate human PrP(Sc) and 'human' prions. These mice therefore provide a model to study experimentally the species barrier limiting BSE transmission to humans. Incubation periods to BSE in transgenic mice are not shortened by expression of human PrP, and only mouse PrP(Sc) is produced in response to such challenge.

Bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease: background, evolution, and current concerns

The epidemic of bovine spongiform encephalopathy (BSE) in the United Kingdom, which began in 1986 and has affected nearly 200,000 cattle, is waning to a conclusion, but leaves in its wake an outbreak of human Creutzfeldt-Jakob disease, most probably resulting from the consumption of beef products contaminated by central nervous system tissue. Although averaging only 10-15 cases a year since its first appearance in 1994, its future magnitude and geographic distribution (in countries that have imported infected British cattle or cattle products, or have endogenous BSE) cannot yet be predicted. The possibility that large numbers of apparently healthy persons might be incubating the disease raises concerns about iatrogenic transmissions through instrumentation (surgery and medical diagnostic procedures) and blood and organ donations. Government agencies in many countries continue to implement new measures to minimize this risk.

SQUID-based microwave cavity search for dark-matter axions

Axions in the microeV mass range are a plausible cold dark-matter candidate and may be detected by their conversion into microwave photons in a resonant cavity immersed in a static magnetic field. We report the first result from such an axion search using a superconducting first-stage amplifier (SQUID) replacing a conventional GaAs field-effect transistor amplifier. This experiment excludes KSVZ dark-matter axions with masses between 3.3 microeV and 3.53 microeV and sets the stage for a definitive axion search utilizing near quantum-limited SQUID amplifiers.

The ecology of childhood overweight: a 12-year longitudinal analysis

OBJECTIVE

To investigate ecological correlates of the development of overweight in a multisite study sample of children followed from age 2 to 12.

DESIGN

Longitudinal examination of covariates of overweight status throughout childhood, with covariates drawn from three ecological levels: sociocultural or demographic, quality of the child's home environment, and proximal child experience that could directly affect the balance between energy intake and energy expenditure.

SUBJECTS

A total of 960 children participating in a long-term longitudinal study provided growth data at least once; 653 of the children had complete data on covariates.

MEASUREMENTS

Height and weight measured seven times between ages 2 and 12 were converted to a body mass index (BMI) and entered into a latent transition analysis to identify patterns of overweight across childhood. Ecological correlates measured longitudinally included demographic characteristics obtained by maternal report, home environment quality obtained by observation and maternal report, and proximal child experience factors obtained by observation, maternal report and child report.

RESULTS

Four patterns of overweight were found: never overweight, overweight beginning at preschool age, overweight beginning in elementary school, and return to normal weight after being overweight at preschool age. The weight status groups differed on home environment quality and proximal child experience factors but not on demographics. Children overweight at preschool had less sensitive mothers than never overweight children. Children overweight at school age had fewer opportunities for productive activity at home than did never overweight children. School-age overweight children also watched the most TV after school. Multivariate logistic regression analyses further indicated the significance to children's weight status of proximal child experience variables. Less physically active children and those who watched more television after school were more likely to become overweight. Results did not vary by child sex.

CONCLUSION

The results support the idea that childhood overweight is multiply determined. The one potentially important and changeable factor identified as a target for intervention centers on how children spend their time, especially their after-school time. Children who are more physically active and spend less time watching TV after school are less likely to become overweight by age 12.

Search for Invisible Axion Dark Matter with the Axion Dark Matter Experiment

This Letter reports the results from a haloscope search for dark matter axions with masses between 2.66 and 2.81  μeV. The search excludes the range of axion-photon couplings predicted by plausible models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume haloscope at subkelvin temperatures, thereby reducing thermal noise as well as the excess noise from the ultralow-noise superconducting quantum interference device amplifier used for the signal power readout. Ongoing searches will provide nearly definitive tests of the invisible axion model over a wide range of axion masses.

BSE: a decade on--Part I

Bovine spongiform encephalopathy (BSE), popularly known as "mad cow disease", was discovered in 1986 and has accounted for the deaths of over 165,000 cattle in the UK (by the end of January, 1997) with about 34,000 (mainly dairy) herds involved. The syndrome in the cow includes changes in posture and temperament, apprehension, and loss of coordination. There are many parallels with scraple in sheep, with similar neuropathological changes in the hindbrain that give it a spongiform appearance under the microscope. The facts have been broadly reviewed in The Lancet in 1990 and 1993, and in much more detail elsewhere. In a two-part article, the first of which appears here, we now summarise recent developments.

A first in human, safety, pharmacokinetics, and clinical activity phase I study of once weekly administration of the Hsp90 inhibitor ganetespib (STA-9090) in patients with solid malignancies

Background

This phase I study investigated the maximum tolerated dose (MTD), safety, pharmacokinetics and antitumor activity of ganetespib in patients with solid malignancies.

Methods

Patients were enrolled in cohorts of escalating ganetespib doses, given as 1 hour IV infusion, once weekly for 3 weeks, followed by a 1-week rest until disease progression or unacceptable toxicity. Endpoints included safety, pharmacokinetic and pharmacodynamic parameters and preliminary clinical activity.

Results

Fifty-three patients were treated at doses escalating from 7 to 259 mg/m². The most common adverse events were Grade 1 and 2 diarrhea, fatigue, nausea or vomiting. Dose-limiting toxicities (DLT) observed were: one Grade 3 amylase elevation (150 mg/m²), one Grade 3 diarrhea and one Grade 3 and one Grade 4 asthenia (259 mg/m²). The MTD was 216 mg/m² and the recommended phase 2 dose was established at 200 mg/m² given IV at Days 1, 8, and 15 every 4 weeks. There was a linear relationship between dose and exposure. Plasma HSP70 protein levels remained elevated for over a week post treatment. Disease control rate (objective response and stable disease at ≥ 16 weeks) was 24.4%.

Conclusions

Ganetespib is well tolerated as a weekly infusion for 3 of every 4 weeks cycle. The recommended phase II dose is 200 mg/m², and is associated with an acceptable tolerability profile.

Trial registration

NCT00687934

Patterns of developmental change in infants' nighttime sleep awakenings from 6 through 36 months of age

Nighttime sleep awakenings and infant and family characteristics were measured longitudinally in more than 1,200 infants when the infants were 6, 15, 24, and 36 months old. By 6 months of age, the majority of children slept through the night, awakening their mothers only about once or twice per week. However, not all children followed this predominant developmental pattern. Using growth mixture modeling, we identified 2 distinct developmental patterns. One group, labeled Sleepers, included 66% of the children. These children showed a flat trajectory of sleep awakenings from 6 through 36 months, with mothers reporting their infant awakening from sleep about 1 night per week. The second group, labeled Transitional Sleepers, included 34% of the infants. These children had 7 reported nights of awakenings per week at 6 months, dropping to 2 nights per week at 15 months and to 1 night per week by 24 months. Compared with Sleepers, Transitional Sleepers were more likely to be boys, score higher on the 6-month difficult temperament assessment, be breastfed at 6 and 15 months old, and have more depressed mothers at 6 months old. Using 2-group structural equation modeling, we examined individual differences at different points on the individual infants' sleep trajectories. For infants in both groups, reported sleep awakenings were associated with difficult temperament measured at 6 months, breastfeeding, infant illness, maternal depression, and greater maternal sensitivity. Infant-mother attachment measures were not related to these sleep awakenings.

Fast Generation of Functional Subtype Astrocytes from Human Pluripotent Stem Cells

Differentiation of astrocytes from human pluripotent stem cells (hPSCs) is a tedious and variable process. This hampers the study of hPSC-generated astrocytes in disease processes and drug development. By using CRISPR/Cas9-mediated inducible expression of NFIA or NFIA plus SOX9 in hPSCs, we developed a method to efficiently generate astrocytes in 4-7 weeks. The astrocytic identity of the induced cells was verified by their characteristic molecular and functional properties as well as after transplantation. Furthermore, we developed a strategy to generate region-specific astrocyte subtypes by combining differentiation of regional progenitors and transgenic induction of astrocytes. This simple and efficient method offers a new opportunity to study the fundamental biology of human astrocytes and their roles in disease processes.

Influence of feeding regimen on body condition in the cat

The influence of feeding regimen on body condition in the cat was studied in a sample of the UK domestic cat population (n = 136). Data were collected by interviewing cat owners and assessing body condition of cats in the owners' homes. Four main factors were identified which were related to body condition. These were, in descending order of significance: neuter status, age, frequency of treat feeding, and ad libitum feeding. Feeding regimen as a risk factor in feline obesity is discussed.

Neuropathology of scrapie: a study of the distribution patterns of brain lesions in 222 cases of natural scrapie in sheep, 1982-1991

Detailed neuropathological findings in 222 cases of naturally occurring scrapie from Great Britain are described. The material consisted of formalin-fixed brain from eight breeds of sheep submitted between 1982 and 1991. Paraffin-embedded histological sections were made from several specified brain areas, including the medulla oblongata, cerebellum, pons, mesencephalon, diencephalon, septal area, basal ganglia and frontal cortex. Sections were examined by conventional and polarised light microscopy and the type and distribution of the lesions were recorded. Histologically, the lesions included vacuolation of neuronal perikarya and grey matter neuropil, neuronal degeneration (especially "dark' neurons) and loss, a reactive glial (predominantly astrocytic) response and amyloidosis. Vacuolar lesions were present in the cerebral cortex of 37 per cent of cases, centred around the superior frontal gyrus. Vacuolar lesions were detected in the neocortex for as long as sections have been taken from the superior frontal gyrus and are thus probably not a new feature of the disease. The distribution of vacuolation in the grey matter neuropil could be classified into seven patterns. Data from individual breeds of sheep showed that in some breeds there were significant differences in the age at which animals with different patterns of vacuolation died from scrapie.

Extended Search for the Invisible Axion with the Axion Dark Matter Experiment

This Letter reports on a cavity haloscope search for dark matter axions in the Galactic halo in the mass range 2.81-3.31  μeV. This search utilizes the combination of a low-noise Josephson parametric amplifier and a large-cavity haloscope to achieve unprecedented sensitivity across this mass range. This search excludes the full range of axion-photon coupling values predicted in benchmark models of the invisible axion that solve the strong CP problem of quantum chromodynamics.

Immunologic and molecular biologic studies of prion proteins in bovine spongiform encephalopathy

Bovine spongiform encephalopathy (BSE) is a transmissible neurodegenerative disease. Six brain regions from 11 cattle were examined for the presence of the abnormal isoform of the prion protein (PrPBSE). The highest concentrations of PrPBSE were found in the brain stem, where the greatest degree of spongiform change was observed. Molecular cloning of the bovine PrP gene showed that it encodes a protein of 256 or 264 amino acids with five or six Gly:Pro-rich octarepeats, respectively, in contrast to all other mammalian PrP genes, which encode only five octarepeats. The bovine PrP gene is single copy, and the entire open-reading frame lies within a single exon. Since the transmission of prions across species seems to be restricted by differences in PrP sequence, the high degree of homology between sheep and bovine PrP (98%) correlates with the proposed cause of BSE.