In a subset of patients with cystic fibrosis (CF), nonsense mutations (premature stop codons) disrupt production of full-length, functional CF transmembrane conductance regulator (CFTR). Ataluren ...(PTC124) allows ribosomal readthrough of premature stop codons in mRNA. We evaluated drug activity and safety in patients with nonsense mutation CF who took ataluren three times daily (morning, midday and evening) for 12 weeks at either a lower dose (4, 4 and 8 mg·kg(-1)) or higher dose (10, 10 and 20 mg·kg(-1)). The study enrolled 19 patients (10 males and nine females aged 19-57 yrs; dose: lower 12, higher seven) with a classic CF phenotype, at least one CFTR nonsense mutation allele, and an abnormal nasal total chloride transport. Both ataluren doses were similarly active, improving total chloride transport with a combined mean change of -5.4 mV (p<0.001), and on-treatment responses (at least -5 mV improvement) and hyperpolarisations (values more electrically negative than -5 mV) in 61% (p<0.001) and 56% (p = 0.002) of patients. CFTR function was greater with time and was accompanied by trends toward improvements in pulmonary function and CF-related coughing. Adverse clinical and laboratory findings were uncommon and usually mild. Chronic ataluren administration produced time-dependent improvements in CFTR activity and clinical parameters with generally good tolerability.
Coronavirus disease 2019 (COVID-19) causes a spectrum of disease; some patients develop a severe proinflammatory state which can be associated with a unique coagulopathy and procoagulant endothelial ...phenotype. Initially, COVID-19 infection produces a prominent elevation of fibrinogen and D-dimer/fibrin(ogen) degradation products. This is associated with systemic hypercoagulability and frequent venous thromboembolic events. The degree of D-dimer elevation positively correlates with mortality in COVID-19 patients. COVID-19 also leads to arterial thrombotic events (including strokes and ischemic limbs) as well as microvascular thrombotic disorders (as frequently documented at autopsy in the pulmonary vascular beds). COVID-19 patients often have mild thrombocytopenia and appear to have increased platelet consumption, together with a corresponding increase in platelet production. Disseminated intravascular coagulopathy (DIC) and severe bleeding events are uncommon in COVID-19 patients. Here, we review the current state of knowledge of COVID-19 and hemostasis.
Fetal growth restriction (FGR) is a significant complication of pregnancy describing a fetus that does not grow to full potential due to pathological compromise. FGR affects 3–9% of pregnancies in ...high‐income countries, and is a leading cause of perinatal mortality and morbidity. Placental insufficiency is the principal cause of FGR, resulting in chronic fetal hypoxia. This hypoxia induces a fetal adaptive response of cardiac output redistribution to favour vital organs, including the brain, and is in consequence called brain sparing. Despite this, it is now apparent that brain sparing does not ensure normal brain development in growth‐restricted fetuses. In this review we have brought together available evidence from human and experimental animal studies to describe the complex changes in brain structure and function that occur as a consequence of FGR. In both humans and animals, neurodevelopmental outcomes are influenced by the timing of the onset of FGR, the severity of FGR, and gestational age at delivery. FGR is broadly associated with reduced total brain volume and altered cortical volume and structure, decreased total number of cells and myelination deficits. Brain connectivity is also impaired, evidenced by neuronal migration deficits, reduced dendritic processes, and less efficient networks with decreased long‐range connections. Subsequent to these structural alterations, short‐ and long‐term functional consequences have been described in school children who had FGR, most commonly including problems in motor skills, cognition, memory and neuropsychological dysfunctions.
The structural and functional deficits that are associated with fetal growth restriction in human infants are dependent on a number of important factors, including the timing of the onset of placental insufficiency and subsequent fetal hypoxia and hypoglycaemia, the severity of fetal compromise, whether the FGR infant is born preterm or at term, whether coexisting complications are present, and the cerebrovascular responses including whether brain sparing is evident and the severity of brain sparing, as well as the spatial redistribution of brain blood flow.
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•The complex biology of intracellular cholesterol trafficking and its delivery to steroidogenic mitochondria is incompletely understood.•Paradoxically, the known human disorders of ...intracellular cholesterol trafficking have only modest effects on adrenal steroidogenesis.•The Steroidogenic Acute Regulatory Protein (StAR) does not deliver cholesterol to mitochondria but instead promotes its transfer from the outer to inner mitochondrial membrane.•Congenital lipoid adrenal hyperplasia (mutant StAR) typically presents with severe adrenal insufficiency and 46,XY sex reversal but may also be seen in milder non-classic, adult forms.•Disorders of P450scc, the cholesterol side-chain cleavage enzyme are much rarer and resemble lipoid CAH clinically and hormonally, but do not exhibit its massive adrenal enlargement.
Steroidogenesis begins with cellular internalization of low-density lipoprotein particles and subsequent intracellular processing of cholesterol. Disorders in these steps include Adrenoleukodystrophy, Wolman Disease and its milder variant Cholesterol Ester Storage Disease, and Niemann-Pick Type C Disease, all of which may present with adrenal insufficiency. The means by which cholesterol is directed to steroidogenic mitochondria remains incompletely understood. Once cholesterol reaches the outer mitochondrial membrane, its delivery to the inner mitochondrial membrane is regulated by the steroidogenic acute regulatory protein (StAR). Severe StAR mutations cause classic congenital lipoid adrenal hyperplasia, characterized by lipid accumulation in the adrenal, adrenal insufficiency, and disordered sexual development in 46,XY individuals. The lipoid CAH phenotype, including spontaneous puberty in 46,XX females, is explained by a two-hit model. StAR mutations that retain partial function cause a milder, non-classic disease characterized by glucocorticoid deficiency, with lesser disorders of mineralocorticoid and sex steroid synthesis. Once inside the mitochondria, cholesterol is converted to pregnenolone by the cholesterol side-chain cleavage enzyme, P450scc, encoded by the CYP11A1 gene. Rare patients with mutations of P450scc are clinically and hormonally indistinguishable from those with lipoid CAH, and may also present as milder non-classic disease. Patients with P450scc defects do not have the massive adrenal hyperplasia that characterizes lipoid CAH, but adrenal imaging may occasionally fail to distinguish these, necessitating DNA sequencing.
Cognitive interventions may improve cognition, delay age-related cognitive declines, and improve quality of life for older adults. The current meta-analysis was conducted to update and expand ...previous work on the efficacy of cognitive interventions for older adults and to examine the impact of key demographic and methodological variables. EBSCOhost and Embase online databases and reference lists were searched to identify relevant randomized-controlled trials (RCTs) of cognitive interventions for cognitively healthy or mildly impaired (MCI) older adults (60+ years). Interventions trained a single cognitive domain (e.g., memory) or were multi-domain training, and outcomes were assessed immediately post-intervention using standard neuropsychological tests. In total, 279 effects from 97 studies were pooled based on a random-effects model and expressed as Hedges’
g
(unbiased). Overall, results indicated that cognitive interventions produce a small, but significant, improvement in the cognitive functioning of older adults, relative to active and passive control groups (
g
= 0.298,
p
< .001, 95% CI = 0.248–0.347). These results were confirmed using multi-level analyses adjusting for nesting of effect sizes within studies (
g =
0.362,
p
< .001, 95% CI = 0.275, 0.449). Age, education, and cognitive status (healthy vs. MCI) were not significant moderators. Working memory interventions proved most effective (
g
= 0.479), though memory, processing speed, and multi-domain interventions also significantly improved cognition. Effects were larger for directly trained outcomes but were also significant for non-trained outcomes (i.e., “transfer effects”). Implications for future research and clinical practice are discussed. This project was pre-registered with PROSPERO (#42016038386).
We consider statistical inference for regression when data are grouped into clusters, with regression model errors independent across clusters but correlated within clusters. Examples include data on ...individuals with clustering on village or region or other category such as industry, and state-year differences-in-differences studies with clustering on state. In such settings, default standard errors can greatly overstate estimator precision. Instead, if the number of clusters is large, statistical inference after OLS should be based on cluster-robust standard errors. We outline the basic method as well as many complications that can arise in practice. These include cluster-specific fixed effects, few clusters, multiway clustering, and estimators other than OLS.
Congenital adrenal hyperplasia (CAH) is a group of genetic disorders of adrenal steroidogenesis that impair cortisol synthesis, with compensatory increases in ACTH leading to hyperplastic adrenals. ...The term 'CAH' is generally used to mean 'steroid 21-hydroxylase deficiency' (21OHD) as 21OHD accounts for about 95% of CAH in most populations; the incidences of the rare forms of CAH vary with ethnicity and geography. These forms of CAH are easily understood on the basis of the biochemistry of steroidogenesis. Defects in the steroidogenic acute regulatory protein, StAR, disrupt all steroidogenesis and are the second-most common form of CAH in Japan and Korea; very rare defects in the cholesterol side-chain cleavage enzyme, P450scc, are clinically indistinguishable from StAR defects. Defects in 3β-hydroxysteroid dehydrogenase, which also causes disordered sexual development, were once thought to be fairly common, but genetic analyses show that steroid measurements are generally unreliable for this disorder. Defects in 17-hydroxylase/17,20-lyase ablate synthesis of sex steroids and also cause mineralocorticoid hypertension; these are common in Brazil and in China. Isolated 17,20-lyase deficiency can be caused by rare mutations in at least three different proteins. P450 oxidoreductase (POR) is a co-factor used by 21-hydroxylase, 17-hydroxylase/17,20-lyase and aromatase; various POR defects, found in different populations, affect these enzymes differently. 11-Hydroxylase deficiency is the second-most common form of CAH in European populations but the retention of aldosterone synthesis distinguishes it from 21OHD. Aldosterone synthase deficiency is a rare salt-losing disorder. Mild, 'non-classic' defects in all of these factors have been described. Both the severe and non-classic disorders can be treated if recognized.
Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency (21OHD) has a worldwide incidence of 1 in 15-20,000. Affected individuals have adrenal insufficiency and androgen excess; ...the androgen excess begins during fetal life, typically resulting in 46,XX disordered sexual development. In 21OHD, 17-hydroxyprogesterone (17OHP), the steroid proximal to 21-hydroxylase, accumulates. Most industrialized countries have newborn screening programs that measure 17OHP; such screening has permitted rapid detection of newborns with 21OHD, saving lives previously lost to mineralocorticoid deficiency and salt wasting. However, newborn screening is plagued by false positives. 17OHP is above most "cutoff values" in the first 24 h of life, is high in otherwise normal premature infants, and in many term infants with physiologic stress from unrelated diseases. In addition, newborn 17OHP may be elevated in other forms of CAH, including 11-hydroxylase deficiency, 3β-hydroxysteroid dehydrogenase deficiency, and P450 oxidoreductase deficiency. In 21OHD, some of the accumulated intra-adrenal 17OHP is converted to 21-deoxycortisol (21-deoxy) by 11β-hydroxylase (CYP11B1); 21-deoxy is not elevated in premature infants or in other forms of CAH, and hence is a more specific marker for 21OHD. However, 21-deoxy assays have not been generally available until recently, hence experience is limited. We urge clinical investigators, commercial reference laboratories, and newborn screening programs to investigate replacing 17OHP with 21-deoxy as the analyte of choice for studies of 21OHD.
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