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Background: Previous epidemiological research has linked posttraumatic stress disorder (PTSD) with specific physical health problems, but the comprehensive landscape of medical conditions associated with PTSD remains uncharacterized. Electronic health records provide an opportunity to overcome clinical knowledge gaps and uncover associations with biological relevance that potentially vary by sex., Methods: PTSD was defined among biobank participants ( N  = 145,959) in 3 major healthcare systems using 2 ICD code-based definitions: broad (≥1 PTSD or acute stress codes vs. 0; n cases  = 16,706) and narrow (≥2 PTSD codes vs. 0; n cases  = 3325). Using a phenome-wide association study design, we tested associations between each PTSD definition and all prevalent disease umbrella categories, i.e., phecodes. We also conducted sex-stratified phenome-wide association study analyses including a sex × diagnosis interaction term in each logistic regression., Results: A substantial number of phecodes were significantly associated with PTSD Narrow (61%) and PTSD Broad (83%). While the strongest associations were shared between the 2 definitions, PTSD Broad captured 334 additional phecodes not significantly associated with PTSD Narrow and exhibited a wider range of significantly associated phecodes across various categories, including respiratory, genitourinary, and circulatory conditions. Sex differences were observed in that PTSD Broad was more strongly associated with osteoporosis, respiratory failure, hemorrhage, and pulmonary heart disease among male patients and with urinary tract infection, acute pharyngitis, respiratory infections, and overweight among female patients., Conclusions: This study provides valuable insights into a diverse range of comorbidities associated with PTSD, including both known and novel associations, while highlighting the influence of sex differences and the impact of defining PTSD using electronic health records., (© 2024 The Authors.)

Background: Chronic pain affects one fifth of American adults, contributing significant public health burden. Chronic pain mechanisms can be further understood through investigating brain gene expression., Methods: We tested differentially expressed genes (DEGs) in chronic pain, migraine, lifetime fentanyl and oxymorphone use, and with chronic pain genetic risk in four brain regions (dACC, DLPFC, MeA, BLA) and imputed cell type expression data from 304 postmortem donors. We compared findings across traits and with independent transcriptomics resources, and performed gene-set enrichment., Results: We identified two chronic pain DEGs: B4GALT and VEGFB in bulk dACC. We found over 2000 (primarily BLA microglia) chronic pain cell type DEGs. Findings were enriched for mouse microglia pain genes, and for hypoxia and immune response. Cross-trait DEG overlap was minimal., Conclusions: Chronic pain-associated gene expression is heterogeneous across cell type, largely distinct from that in pain-related traits, and shows BLA microglia are a key cell type.

Opioid use disorder (OUD) looms as one of the most severe medical crises facing society. More effective therapeutics will require a deeper understanding of molecular changes supporting drug-taking and relapse. Here, we develop a brain reward circuit-wide atlas of opioid-induced transcriptional regulation by combining RNA sequencing (RNA-seq) and heroin self-administration in male mice modeling multiple OUD-relevant conditions: acute heroin exposure, chronic heroin intake, context-induced drug-seeking following abstinence, and relapse. Bioinformatics analysis of this rich dataset identified numerous patterns of transcriptional regulation, with both region-specific and pan-circuit biological domains affected by heroin. Integration of RNA-seq data with OUD-relevant behavioral outcomes uncovered region-specific molecular changes and biological processes that predispose to OUD vulnerability. Comparisons with human OUD RNA-seq and genome-wide association study data revealed convergent molecular abnormalities and gene candidates with high therapeutic potential. These studies outline molecular reprogramming underlying OUD and provide a foundational resource for future investigations into mechanisms and treatment strategies.

Major depressive disorder (MDD) is a complex and heterogeneous psychiatric syndrome with genetic and environmental influences. In addition to neuroanatomical and circuit-level disturbances, dysregulation of the brain transcriptome is a key phenotypic signature of MDD. Postmortem brain gene expression data are uniquely valuable resources for identifying this signature and key genomic drivers in human depression; however, the scarcity of brain tissue limits our capacity to observe the dynamic transcriptional landscape of MDD. It is therefore crucial to explore and integrate depression and stress transcriptomic data from numerous, complementary perspectives to construct a richer understanding of the pathophysiology of depression. In this review, we discuss multiple approaches for exploring the brain transcriptome reflecting dynamic stages of MDD: predisposition, onset, and illness. We next highlight bioinformatic approaches for hypothesis-free, genome-wide analyses of genomic and transcriptomic data and their integration. Last, we summarize the findings of recent genetic and transcriptomic studies within this conceptual framework., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Cocaine use disorder (CUD) is an intractable syndrome, and rising overdose death rates represent a substantial public health crisis that exacts tremendous personal and financial costs on patients and society. Sharp increases in cocaine use drive the urgent need for better mechanistic insight into this chronic relapsing brain disorder that currently lacks effective treatment options. To investigate the transcriptomic changes involved, we conducted RNA sequencing on two striatal brain regions that are heavily implicated in CUD, the nucleus accumbens and caudate nucleus, from men suffering from CUD and matched controls. Weighted gene coexpression analyses identified CUD-specific gene networks enriched in ionotropic receptors and linked to lowered neuroinflammation, contrasting the proinflammatory responses found in opioid use disorder. Integration of comprehensive transcriptomic datasets from mouse cocaine self-administration models revealed evolutionarily conserved gene networks in CUD that implicate especially D1 medium spiny neurons as drivers of cocaine-induced plasticity.

Regions of hypoxia are common in solid tumors and drive changes in gene expression that increase risk of cancer metastasis. Tumor cells must respond to the stress of hypoxia by activating genes to modify cell metabolism and antioxidant response to improve survival. The goal of the current study was to determine the effect of hypoxia on cell metabolism and markers of oxidative stress in metastatic (metM-Wnt lung ) compared with nonmetastatic (M-Wnt) murine mammary cancer cell lines. We show that hypoxia induced a greater suppression of glutamine to glutamate conversion in metastatic cells (13% in metastatic cells compared to 7% in nonmetastatic cells). We also show that hypoxia increased expression of genes involved in antioxidant response in metastatic compared to nonmetastatic cells, including glutamate cysteine ligase catalytic and modifier subunits and malic enzyme 1. Interestingly, hypoxia increased the mRNA level of the transaminase glutamic pyruvic transaminase 2 (Gpt2, 7.7-fold) only in metM-Wnt lung cells. The change in Gpt2 expression was accompanied by transcriptional (4.2-fold) and translational (6.5-fold) induction of the integrated stress response effector protein activating transcription factor 4 (ATF4). Genetic depletion ATF4 demonstrated importance of this molecule for survival of hypoxic metastatic cells in detached conditions. These findings indicate that more aggressive, metastatic cancer cells utilize hypoxia for metabolic reprogramming and induction of antioxidant defense, including activation of ATF4, for survival in detached conditions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kiesel, Sheeley, Hicks, Andolino, Donkin, Wendt, Hursting and Teegarden.)

Microglia have emerged as important players in brain aging and pathology. To understand how genetic risk for neurological and psychiatric disorders is related to microglial function, large transcriptome studies are essential. Here we describe the transcriptome analysis of 255 primary human microglial samples isolated at autopsy from multiple brain regions of 100 individuals. We performed systematic analyses to investigate various aspects of microglial heterogeneities, including brain region and aging. We mapped expression and splicing quantitative trait loci and showed that many neurological disease susceptibility loci are mediated through gene expression or splicing in microglia. Fine-mapping of these loci nominated candidate causal variants that are within microglia-specific enhancers, finding associations with microglial expression of USP6NL for Alzheimer's disease and P2RY12 for Parkinson's disease. We have built the most comprehensive catalog to date of genetic effects on the microglial transcriptome and propose candidate functional variants in neurological and psychiatric disorders., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Aims and Objectives: To describe the spirituality and religiosity of 30 non-directed (altruistic) living kidney donors in the USA and explore how they may have affected their motivations to donate and donation process experiences., Background: The rise in non-directed donors and their ability to initiate kidney chains offer a novel approach to help alleviate the overextended kidney transplant wait list in the USA. However, little is known about the non-directed donors' motivations, characteristics and experiences., Design: We conducted a qualitative-dominant study and used a grounded theory approach to analyse data., Methods: Thirty participants completed in-depth interviews between April 2013-April 2015. Three analysts independently read and coded interview transcripts. Grounded theory techniques were used to develop descriptive categories and identify topics related to the non-directed donors donation experience., Results: Sixteen of the 30 non-directed donorss discussed the topic of spirituality and religiosity when describing their donation experiences, regardless of whether they were actively practising a religion at the time of donation. Specifically, three themes were identified within spirituality and religiosity: motivation to donate, support in the process, and justification of their donation decisions postdonation., Conclusions: Findings from this study are the first to describe how spirituality and religiosity influenced the experiences of U.S. non-directed donorss and may help improve non-directed donors educational resources for future spiritual or religious non-directed donors, and the overall non-directed donors donation experience in efforts to increase the living donor pool., Relevance to Clinical Practice: Spirituality and religiosity are often overlooked yet potentially influential factors in Western medicine, as demonstrated through the experiences of Jehovah's Witnesses and their religious restrictions while undergoing surgery and the beliefs of Christian Scientists against taking medications and receiving medical procedures. Understanding needs of non-directed donors specifically with spirituality and religiosity can better position kidney transplant centres and teams to improve predonation screening of non-directed donor candidates and provide support services during the donation process., (© 2017 John Wiley & Sons Ltd.)

The disparity between kidney transplant candidates and donors necessitates innovations to increase organ availability. Transporting kidneys allows for living donors and recipients to undergo surgery with a familiar transplant team, city, friends, and family. The effect of shipping kidneys and prolonged cold ischemia time (CIT) with living donor transplantation outcomes is not clearly known. This retrospective matched (age, gender, race, and year of procedure) cohort study compared allograft outcomes for shipped live donor kidney transplants and nonshipped living donor kidney transplants. Fifty-seven shipped live donor kidneys were transplanted from 31 institutions in 26 cities. The mean shipping distance was 1634 miles (range 123-2811) with mean CIT of 12.1 ± 2.8 h. The incidence of delayed graft function in the shipped cohort was 1.8% (1/57) compared to 0% (0/57) in the nonshipped cohort. The 1-year allograft survival was 98% in both cohorts. There were no significant differences between the mean serum creatinine values or the rates of serum creatinine decline in the immediate postoperative period even after adjusted for gender and differences in recipient and donor BMI. Despite prolonged CITs, outcomes for shipped live donor kidney transplants were similar when compared to matched nonshipped living donor kidney transplants., (© 2014 Steunstichting ESOT.)

Purpose/objectives: To investigate how familial communication about prostate cancer (PCa) risk and screening affects sons of men with PCa., Research Approach: Qualitative grounded theory., Setting: Southern California., Participants: 17 Latino sons of PCa survivors., Methodologic Approach: The team conducted semistructured interviews and follow-up interviews. Therefore, the sample includes 25 transcripts. Data were analyzed with a mix of a priori topical codes and grounded theory techniques., Findings: Sons were in need of information about familial risk and screening options. They became sensitized to PCa, desired information, and held protective intentions. Hopeful intentions came up against cultural taboos around sex, reproductive health, and intimacy that limited discussions between fathers and sons. Fathers were a valued source of information but play various roles, which affect sons' screening intentions. Open communication between father and son promoted awareness of screening and familial risk., Conclusions: Uncertainty about familial risk and screening options, especially early detection strategies, was exacerbated by cultural taboos around PCa. Fathers could have been primary and credible advocates for shared decision making, but sons had difficulty learning from their fathers' experience., Interpretation: FINDINGS from the study can help inform community-based interventions with Latino families, help to culturally tailor health messaging, and sensitize clinicians to a group that needs concerted counseling about PCa risk and screening.

Despite a growing awareness that prostate cancer is a "couple's disease," the coping strategies, subjective distress, and emotional needs of partners are not adequately addressed. To better understand wives' experiences and processes they enact, we recruited 28 low-income Latinas caring for husbands recovering from prostatectomies to participate in interviews at three time points. Their narratives destabilize a common focus on physical side effects and an implicit bias toward men's reactions. We critically examine an overarching process of normalization, with underlying themes working both toward and against normality. We identified dissonance between detailed accounts of major lifestyle changes and professed normalization. We detail the women's purposeful methods to counteract negative impacts on their lives while seeking support externally. A better understanding of women's strategies and coping is critical to design interventions and education to both capitalize on partners' role in recovery while also addressing hidden causes of increased subjective distress.

Nanosphere lithography (NSL) is an inexpensive, high throughput, materials general nanofabrication technique capable of producing a large variety of nanoscale structures including well-ordered 2 dimensional nanoparticle arrays. In this review, we will summarize the most recent advances in the fabrication of size-tunable nanoparticles using NSL. Four examples of new NSL-derived materials will be described: (1) The development of a method to release NSL nanoparticles from the substrate for applications in solution environments, (2) the fabrication of triangular nanoholes with reactive ion etching, (3) the electrochemical fine tuning of the structure of a silver nanoparticle and the wavelength of its localized surface plasmon resonance (LSPR), and (4) the growth of ultra thin protective dielectric layers on NSL-fabricated Ag nanotriangles using atomic layer deposition (ALD).

In this work, a detailed and systematic study of the plasmonic properties of a novel film over nanowell surface is investigated. These nanostructures are fabricated using nanosphere lithography and reactive ion etching and structurally characterized by AFM and SEM. The resulting structures show remarkably narrow plasmon bands in reflectance spectra (as little as 0.10 eV) and greater sensitivity to external dielectric environment than has been seen in other nanoparticle systems, resulting in an improvement in the figure of merit (FOM = refractive index sensitivity (eV.RIU(-1))/full width at half-maximum (eV)) for refractive index sensing. Theoretical modeling for the plasmon spectra of these nanostructures is done using discrete dipole approximation code under periodic boundary conditions. The modeling results match the measurements accurately in aspects of the variation of the plasmon line shape with altering internanowell distance and dielectric environment.

An electrochemical method is developed to quantitatively modify and spectroscopically monitor the size and shape of Ag nanotriangles fabricated by nanosphere lithography (NSL) on an indium tin oxide (ITO) electrode surface. AFM and SEM results demonstrate that the preferential order of electrochemical oxidation for a nanotriangle is, surprisingly, bottom edges first, then triangular tips, then out-of-plane height.

The effect of diffractive coupling on the collective plasmon line shape of linear arrays of Ag nanoparticles fabricated by electron beam lithography has been investigated using Rayleigh scattering spectroscopy. The array spectra exhibit an intricate multi-peak structure, including a narrow mode that gains strength for interparticle distances that are close to the single particle resonance wavelength. A version of the discrete dipole approximation method provides an excellent qualitative description of the observed behavior.

Frequency-scanned excitation profiles of coherent second harmonic generation (SHG) were measured for silver nanoparticle arrays prepared by nanosphere lithography. The frequency of the fundamental beam did not coincide with the localized surface plasmon resonance (LSPR) of the nanoparticles and was tuned so that the coherent second harmonic (SH) emission was in the region of the LSPR at 720-750 nm. The SH emission from the arrays was compared with a smooth silver film to identify an enhancement of SH emission efficiency that peaks near approximately 650 nm for nanoparticles 50 nm in height. The polarization and orientation dependence of this enhancement suggests that it is related to a dipolar LSPR mode polarized normal to the plane of the substrate. Linear extinction spectra are dominated by in-plane dipoles and do not show this weak out-of-plane LSPR mode. The nanoparticle arrays are truncated tetrahedrons symmetrically oriented by nanosphere lithography to cancel SH from in-plane dipoles which allows observation of the weak out-of-plane component.

Researchers and industrialists have taken advantage of the unusual optical, magnetic, electronic, catalytic, and mechanical properties of nanomaterials. Nanoparticles and nanoscale materials have proven to be useful for biological uses. Nanoscale materials hold a particular interest to those in the biological sciences because they are on the same size scale as biological macromolecules, proteins and nucleic acids. The interactions between biomolecules and nanomaterials have formed the basis for a number of applications including detection, biosensing, cellular and in situ hybridisation labelling, cell tagging and sorting, point-of-care diagnostics, kinetic and binding studies, imaging enhancers, and even as potential therapeutic agents. Noble metal nanoparticles are especially interesting because of their unusual optical properties which arise from their ability to support surface plasmons. In this review the authors focus on biological applications and technologies that utilise two types of related plasmonic phenomonae: localised surface plasmon resonance (LSPR) spectroscopy and surface-enhanced Raman spectroscopy (SERS). The background necessary to understand the application of LSPR and SERS to biological problems is presented and illustrative examples of resonant Rayleigh scattering, refractive index sensing, and SERS-based detection and labelling are discussed.

Seventy-five families of children with intractable epilepsy but without a severe learning disability (mean age 7 years 1 month, SD 2 years 6 months; range 2 to 12 years) who attended a regional paediatric neurology service, were surveyed. A postal questionnaire was used which included standardized measures of child and family adjustment; forty-eight families responded (64%; 31 males, 17 females). There was no significant difference between responders and non-responders in terms of age, sex, number of other chronic illnesses and disabilities, age at epilepsy diagnosis, seizure type, nor number of antiepileptic drugs currently prescribed (p > 0.05). The importance of including multidimensional measures of outcome was highlighted by the finding that epilepsy, pharmacological, and psychosocial factors were differentially associated with specific adjustment difficulties. Two factors appeared to be most pervasively implicated across a range of adjustment problems: frequency of rectal diazepam administration and family patterns of relating to each other (p < 0.05). It appeared that duration of seizures (as indicated by frequency of rectal diazepam administration), rather than the frequency of seizures per se, was more pernicious in terms of poor adjustment. Intrafamilial relations (degree of conflict/cohesion and soon) were not only associated with adjustment difficulties in the child, but also with the frequency of seizures themselves. Implications for psychological interventions in intractable epilepsy in childhood are highlighted.

Psychological interventions aimed at seizure management are described with a 14-year-old boy with a learning disability and intractable epilepsy. Baseline records suggested that a majority of tonic seizures and 'drop attacks' were associated with going off to sleep and by environmental 'startles'. Psychological formulation implicated sudden changes in arousal levels as an underlying mechanism of action. Cognitive-behavioural countermeasures were employed to alter arousal levels and processes in different ways in different 'at-risk' situations. A multiple baseline design was used to control for non-specific effects of interventions on non-targeted seizures. Results suggested significant declines in the number of sleep onset and startle-response seizures were attained by these methods. Gains were maintained at 2-month follow-up., (Copyright 1999 BEA Trading Ltd.)

The inheritance of a mutant copy of the BRCA1 gene greatly increases a woman's lifetime risk for ovarian and breast cancer. While a homologous gene has been identified in mouse, mice carrying mutations in this gene do not display a detectable increase in tumor formation. To determine whether mutations in p53 might increase the incidence of tumors associated with the loss of BRCA1 function in mice, we have generated mice carrying mutations at both of these loci. We report here that the presence of a mutant Brca1 allele does not alter survival of either p53-/- or p53+/- mice. Although the tumor spectrum was not dramatically altered, an increased incidence of mammary tumors was observed in the Brca1+/-p53-/- mice. Four mammary tumors were seen in the Brca1+/-p53-/- group whereas only one such tumor was seen among the p53-/- control group. In addition, although the presence of a mutant Brca1 allele did not alter the survival rate or the incidence of most tumor types in the p53+/- mice, 5 of the 23 tumors isolated from the Brca1+/-p53+/- mice treated with ionizing radiation were of mammary epithelial origin, and 3 of these had lost expression of the wild-type Brca1 gene. In contrast, no such tumors were observed in the irradiated p53+/- controls. Although the number of mammary tumors observed in these animals is small, these results are suggestive of a role for BRCA1 in mammary tumor formation after exposure to specific DNA damaging agents.

In the cystic fibrosis (CF) patient, lung function decreases throughout life as a result of continuous cycles of infection, particularly with Pseudomonas aeruginosa and Staphylococcus aureus. The mechanism underlying the pathophysiology of the disease in humans has not been established. However, it has been suggested that abnormal, tenacious mucus, resulting perhaps from improper hydration from loss of Cl- secretion via the cystic fibrosis transmembrane conductance regulator (CFTR) protein, impairs clearance of bacteria from the CF airway and provides an environment favorable to bacterial growth. If this hypothesis is correct, it could explain the absence of respiratory disease in CFTR-deficient mice, since mice have only a single submucosal gland and display few goblet cells in their lower airways, even when exposed to bacteria. To test this hypothesis further, we induced allergic airway disease in CFTR-deficient mice. We found that induction of allergic airway disease in mice, unlike bacterial infection, results in an inflammatory response characterized by goblet cell hyperplasia, increased mucin gene expression, and increased production of mucus. However, we also found that disease progression and resolution is identical in Cftr-/- mice and control animals. Furthermore, we show that the presence of mucus in the Cftr-/- airway does not lead to chronic airway disease, even upon direct inoculation with S. aureus and P. aeruginosa. Therefore, factors in addition to the absence of high levels of mucus secretion protect the mouse from the airway disease seen in human CF patients.

Two siblings, a male and a female, had severe axonal neuropathy and sideroblastic anemia. Despite a distinct clinical picture with areflexia, ataxia, hypotonia, optic atrophy, and progressive sensory neural hearing loss, no definite diagnosis could be reached and the older sibling died at 6 years of age of respiratory failure. It is proposed that the two affected siblings have a new form of autosomal-recessive axonal hereditary sensory motor neuropathy.

A comprehensive study of inherited neuromuscular disease was carried out in Northern Ireland between 1 February 1993 and 30 June 1994. Cases were ascertained from eight different sources and investigations and diagnoses were reviewed. Five hundred and forty three individuals were identified giving an overall prevalence of inherited neuromuscular disease of 1 in 2900 of the population. The prevalence of myotonic dystrophy was higher than that in most previously reported studies and accounted for 25% of all cases. Congenital myopathies were also found more frequently than expected. The overall prevalence compares well with that estimated by Emery from the reported prevalence rates of individual diseases.

Four children, from two families, suffered from fatal degeneration of the cerebral grey matter. Their disease was characterised by intractable epilepsy, epilepsia partialis continua, progressive deterioration, and terminal hepatic dysfunction. EEG showed marked and distinctive slow wave abnormality, visual evoked responses were diminished, and cerebral atrophy was seen on CT scan. Pathological findings were of neuronal loss and hepatic cirrhosis. The combination of cerebral degeneration, hepatic disease and familial occurrence suggests an inborn error of metabolism with autosomal recessive inheritance. The features described are those of Alpers syndrome, especially the recently delineated subgroup with progressive neuronal degeneration and liver disease.

One hundred consecutive cranial computed tomographic scans were reviewed in children aged 0-2 years, presenting to the Royal Belfast Hospital for Sick Children. The mean age at scanning was 8.3 months and 73% of the scans were abnormal. The majority of scans were performed electively (78%). The commonest indication for a scan was seizures (31) and the diagnostic yield was highest where they were associated with other neuro-developmental symptoms. The usefulness of the CT scan was not limited to the abnormal studies but contributed to management in children with normal scans by excluding important intracranial pathology. Developmental CNS malformation (16 scans) and cerebral atrophy (15 scans) were the most frequent CT abnormalities encountered.

The aim of this pilot study was to perform power spectral analysis of the EEGs of term infants following birth asphyxia, to establish its value as a prognostic indicator. 16 term infants were studied over an 18-month period. Power spectral analysis was performed on the EEGs of babies with signs of hypoxic-ischaemic encephalopathy at regular intervals during the first five days of life. It showed distinct changes following birth asphyxia, which were related to the eventual outcome of the babies. Absolute power was significantly reduced in the babies with poor outcome compared with those with good outcome, particularly in the delta bands.

Reye's syndrome, an uncommon childhood encephalopathy of uncertain aetiology, is an important cause of mortality and permanent handicap. Since its recognition treatment has changed, current management focusing upon prevention or control of raised intracranial pressure. Prognosis is radically improved by early recognition and prompt transfer to a specialist centre.

Direct measurements of arterial blood pressure and intracranial pressure were recorded in 39 patients aged 3.6 months to 5 years 11 months with Reye's syndrome judged to be stage 2 or beyond. Of 33 patients who survived, 27 made a full recovery and six were severely handicapped. Measurement of cerebral perfusion pressure, which is greatly reduced in the more severe forms of Reye's syndrome, was a better guide to prognosis and management than intracranial pressure alone. The findings emphasise that maintenance of cerebral perfusion pressure is essential if mortality and morbidity are to be reduced. Intracranial monitoring is mandatory in all but the mildest cases of Reye's syndrome.

A family of synthetic elastic fibers, designated spandex fibers, has been developed, providing new degrees of sheerness and effective "power" in elastic fabrics. These fibers have segmented polyurethane structures. They are durable, they are white and accept dye readily, and they can be set by heat. The development of these fibers has led to new textile technology and to new uses for elastic fabrics.