Late-onset apparent mineralocorticoid excess caused by novel compound heterozygous mutations in the HSD11B2 gene

Mutations in the gene encoding 11beta-hydroxysteroid dehydrogenase type 2, 11beta-HSD2 (HSD11B2), explain the molecular basis for the syndrome of apparent mineralocorticoid excess (AME), characterized by severe hypertension and hypokalemic alkalosis. Cortisol is the offending mineralocorticoid in AME, as the result of a lack of 11beta-HSD2-mediated cortisol to cortisone inactivation. In this study, we describe mutations in the HSD11B2 gene in 3 additional AME kindreds in which probands presented in adult life, with milder phenotypes including the original seminal case reported by Stewart and Edwards. Genetic analysis of the HSD11B2 gene revealed that all probands were compound heterozygotes, for a total of 7 novel coding and noncoding mutations. Of the 7 mutations detected, 6 were investigated for their effects on gene expression and enzyme activity by the use of mutant cDNA and minigene constructs transfected into HEK 293 cells. Four missense mutations resulted in enzymes with varying degrees of activity, all <10% of wild type. A further 2 mutations generated incorrectly spliced mRNA and predicted severely truncated, inactive enzyme. The mothers of 2 probands heterozygous for missense mutations have presented with a phenotype indistinguishable from "essential" hypertension. These genetic and biochemical data emphasize the heterogeneous nature of AME and the effects that heterozygosity at the HSD11B2 locus can have on blood pressure in later life.     

COX-2-dependent cardiac failure in Gh/tTG transgenic mice

Gh is a GTP binding protein that couples to the thromboxane receptor (TP), but also functions as tissue transglutaminase II (tTG). A transgenic mouse model was generated in which Gh was overexpressed (GhOE) in ventricular myocytes under the control of the alpha-myosin heavy chain promoter. Heart rate was elevated and both blood pressure and left ventricular ejection fraction were depressed in GhOEs. Left ventricular mass was increased, consistent with genetic and ultrastructural evidence of hypertrophy. Fibrosis and apoptosis were also augmented. Survival declined disproportionately in older GhOEs. Cardiomyocyte expression of COX-2, thromboxane synthase (TxS), and the receptors for TxA2 (the TP), PGF2alpha (the FP), and PGI2 (the IP) were upregulated and urinary 8,12-iso-iPF2alpha-VI,2,3-dinor-6-keto-PGF1alpha and 2,3-dinor-thromboxane B2 were increased in GhOEs, reflecting increased lipid peroxidation and cyclooxygenase (COX) activation. Selective COX-2 inhibition, TP antagonism, and suppression of lipid peroxidation each rescued the cardiac phenotype. Infusion of an FP agonist exacerbated the phenotype, whereas administration of an IP agonist improved cardiac function. Directed cardiac overexpression of Gh/tTG causes both TG activation and increased TP/Gh-dependent signaling. The COX-2-dependent increase in TxA2 generation augments cardiac hypertrophy, whereas formation of PGI2 by the same isozyme ameliorates the phenotype. Oxidant stress may contribute, via regulation of COX-2 expression and/or ligation of the TP and the FP by isoprostanes. Gh/tTG activation regulates expression of COX-2 and its products may differentially modulate cardiomyocyte commitment to cell death or survival.     

Quantitative susceptibility mapping and 23Na imaging‐based in vitro characterization of blood clotting kinetics

Blood clotting is a fundamental biochemical process in post‐hemorrhagic hemostasis. Although the varying appearance of coagulating blood in T₁‐ and T₂‐weighted images is widely used to qualitatively determine bleeding age, the technique permits only a rough discrimination of coagulation stages, and it remains difficult to distinguish acute and chronic hemorrhagic stages because of low T₁‐ and T₂‐weighted signal intensities in both instances. To investigate new biomedical parameters for magnetic resonance imaging‐based characterization of blood clotting kinetics, sodium imaging and quantitative susceptibility mapping (QSM) were compared with conventional T₁‐ and T₂‐weighted imaging, as well as with biochemical hemolysis parameters. For this purpose, a blood‐filled spherical agar phantom was investigated daily for 14 days, as well as after 24 days at 7 T after initial preparation with fresh blood. T₁‐ and T₂‐weighted sequences, a three‐dimensional (3D) gradient echo sequence and a density‐adapted 3D radial projection reconstruction pulse sequence for ²³Na imaging were applied. For hemolysis estimations, free hemoglobin and free potassium concentrations were measured photometrically and with the direct ion‐selective electrode method, respectively, in separate heparinized whole‐blood samples along the same timeline. Initial mean susceptibility was low (0.154 ± 0.020 ppm) and increased steadily during the course of coagulation to reach up to 0.570 ± 0.165 ppm. The highest total sodium (NaT) values (1.02 ± 0.06 arbitrary units) in the clot were observed initially, dropped to 0.69 ± 0.13 arbitrary units after one day and increased again to initial values. Compartmentalized sodium (NaS) showed a similar signal evolution, and the NaS/NaT ratio steadily increased over clot evolution. QSM depicts clot evolution in vitro as a process associated with hemoglobin accumulation and transformation, and enables the differentiation of the acute and chronic coagulation stages. Sodium imaging visualizes clotting independent of susceptibility and seems to correspond to clot integrity. A combination of QSM and sodium imaging may enhance the characterization of hemorrhage.     

Utility of Autopsy among Pediatric Allogeneic Hematopoietic Stem Cell Transplant Recipients: One Last Chance to Learn?

Autopsy may confirm clinical diagnoses or identify conditions that were not suspected prior to a patient's death. Previous studies evaluating the utility of autopsy in hematopoietic stem cell transplant (HSCT) recipients yielded conflicting results.We conducted a retrospective cohort study of children (<18 years of age) undergoing allogeneic HSCT at Duke University who died of any cause between January 1, 1995, and December 31, 2016. We evaluated associations between patient characteristics and autopsy performance using chi-square or Fisher exact tests. We reviewed autopsy reports to determine the concordance between preautopsy causes of death and pathological diagnoses identified on autopsy. We classified unexpected diagnoses on autopsy using criteria developed by Goldman et al. We evaluated for temporal changes in the autopsy consent rate and the frequency of unexpected diagnoses on autopsy using Cochran-Armitage tests.During the 22-year study period, 475 patients died and had data available on autopsy performance, and 130 (27%) of these patients underwent autopsy. The autopsy consent rate declined over time (P < .0001), with autopsies being performed for 40% of deaths in 1995 to 1999 and 17% of deaths in 2009 to 2016. White patients were more likely to undergo autopsy than nonwhite patients (P?=?.03). There were no associations between autopsy performance and patient age, sex, HSCT indication, or HSCT donor. Unexpected diagnoses were identified in 31 (24%) autopsies. The proportion of autopsies with an unexpected diagnosis did not change during the study period (P?=?.45). However, infectious diagnoses that would have led to a change in management were more frequently identified on autopsies in 1995 to 2003 than in 2004 to 2016 (20% versus 0%; P?=?.001).The autopsy consent rate for pediatric HSCT recipients at our institution has declined substantially over the past several decades. The utility of autopsy in this patient population remains high despite a reduction in the identification of unexpected infections.     

The complete genome sequence of a third distinct baculovirus isolated from the true armyworm, <Emphasis Type="Italic">Mythimna unipuncta</Emphasis>, contains two copies of the <Emphasis Type="Italic">lef</Emphasis>-<Emphasis Type="Italic">7</Emphasis> gene

A baculovirus isolate from a USDA Forest Service collection was characterized by electron microscopy and analysis of its genome sequence. The isolate, formerly referred to as Pseudoletia (Mythimna) sp. nucleopolyhedrovirus #7 (MyspNPV#7), was determined by barcoding PCR to derive from the host species Mythimna unipuncta (true armyworm) and was renamed Mythimna unipuncta nucleopolyhedrovirus #7 (MyunNPV#7). The occlusion bodies (OBs) and virions exhibited a size and morphology typical for OBs produced by the species of genus Alphabaculovirus, with occlusion-derived virions consisting of 2–5 nucleocapsids within a single envelope. The MyunNPV#7 genome was determined to be 148,482 bp with a 48.58% G+C nucleotide distribution. A total of 159 ORFs of 150 bp or larger were annotated in the genome sequence, including the 38 core genes of family Baculoviridae. The genome contained six homologous repeat regions (hrs) consisting of multiple copies of a 34-bp imperfect palindrome. Phylogenetic inference from concatenated baculovirus core gene amino acid sequence alignments placed MyunNPV#7 with group II alphabaculoviruses isolated from other armyworm and cutworm host species of lepidopteran family Noctuidae. MyunNPV#7 could be distinguished from other viruses in this group on the basis of differences in gene content and order. Pairwise nucleotide distances suggested that MyunNPV#7 represents a distinct species in Alphabaculovirus. The MyunNPV#7 genome was found to contain two copies of the late expression factor-7 (lef-7) gene, a feature not reported for any other baculovirus genome to date. Both copies of lef-7 encoded an F-box domain, which is required for the function of LEF-7 in baculovirus DNA replication.     

Testing an Online,Theory-Based Intervention to Reduce Pre-drinking Alcohol Consumption and Alcohol-Related Harm in Undergraduates: a Randomized Controlled Trial

Purpose

The present study tested the efficacy of a theory-based online intervention comprising motivational (autonomy support) and volitional (implementation intention) components to reduce pre-drinking alcohol consumption and alcohol-related harm.

Method

Undergraduate students (N?=?202) completed self-report measures of constructs from psychological theories, pre-drinking alcohol consumption, and alcohol-related harm at baseline and were randomly assigned to one of four intervention conditions in a 2 (autonomy support: present/absent)?×?2 (implementation intention: present/absent) design. Participants completed follow-up measures of all variables at 4 weeks post-intervention. All participants received national guidelines on alcohol consumption and an e-mail summary of intervention content at its conclusion. Participants also received weekly SMS messages in the 4-week post-intervention period restating content relevant to their intervention condition.

Results

Neither statistically significant main effect for either the autonomy support or implementation intention intervention components nor an interaction effect was found on the outcome measures. However, statistically significant reductions in pre-drinking alcohol consumption and alcohol-related harm were observed across all groups at follow-up, when compared to baseline.

Conclusion

Reductions in outcome measures were likely related to elements common to each condition (i.e., provision of national guidelines, assessment of outcome measures, e-mail summary, and SMS messages), rather than motivational and volitional components.

     

Multivariable analysis of heart rate recovery after cycle ergometry in heart failure: exercise in heart failure

Purpose

The purpose of this study was to investigate the association between impairment in heart rate recovery (HR_rec) after cycle ergometry and prognostic markers in patients with heart failure (HF) compared with healthy controls.

Methods

Fifty patients with chronic HF (systolic HF, N = 30; diastolic HF, N = 20; mean age = 62 ± 12 years) and 50 healthy controls (N = 50; mean age = 66 ± 13 years) underwent 2-dimensional and M-mode echocardiography followed by cardiopulmonary exercise testing. Independent predictors of HR_rec at 1 and 2 minutes after exercise were analyzed by univariable and multivariable regression analyses, and receiver operating characteristics were performed to obtain area under the curve.

Results

In HF, left ventricular end-diastolic diameter (millimeters), left ventricular ejection fraction (%), N-terminal pro-brain natriuretic peptide (picograms/milliliter), peak oxygen uptake (VO₂peak [milliliters/kilogram/min]), and peak heart rate (HR_peak) showed a significant association with HR_rec (beats/min) in univariate regression analyses (P < .001), but only VO₂peak remained independently predictive of both HR_rec1 (P = .034) and HR_rec2 (P = .008) in the multivariable regression analyses. In controls, VO₂peak (P = .035) and HR_peak (P = .032) were significantly associated with HR_rec2 in univariate analyses only. Optimal cutoff values for discriminating HF versus non-HF based on HR_rec were 17.5 beats/min (sensitivity 92%; specificity 74%) for HR_rec1 and 31.5 beats/min (sensitivity 94%; specificity 86%) for HR_rec2. Optimal cutoff values for discriminating systolic HF versus diastolic HF were 12.5 beats/min (sensitivity 78%; specificity 80%) for HR_rec1 and 24.5 beats/min (sensitivity 82%; specificity 90%) for HR_rec2.

Conclusion

Impairment in after exercise HR_rec is significantly and independently associated with VO2peak in HF and thus might constitute a useful tool for assessing the degree of functional status during exercise rehabilitation.     

Delirium and the functional recovery of older medical inpatients after acute illness: The significance of biological factors

Previous studies have not clarified the relationship of delirium to functional capacity during acute illness. We have investigated this relationship, incorporating the potential roles of APOE genotype and circulating cytokines in a longitudinal study of acutely admitted patients aged 70+ years. In all participants was measured the: Barthel Index (BI), mini-mental state examination (MMSE), confusion assessment method (CAM), delirium rating scale (DRS), APACHE II, APOE genotype. In a sub-sample: serum interferon-γ (IFN-γ), interleukin-1 (Levels of IL-1α, IL-1β and IL-1 receptor antagonist activity IL-1RA), interleukin-6 (IL-6), leukemia inhibitory factor (LIF), tumor necrosis factor-α (TNF-α) and insulin-like growth factor-I (IGF-I). Of 164 participants, mean age 84.6 ± 6.57 years (±S.D.), 67.1% were women. On first assessment, mean BI was 14.13 ± 4.46 and delirium prevalence was 25.6%. At discharge, the mean BI of survivors (n = 150) was 15.61 ± 4.22. By discharge, survivors who had recovered from prevalent delirium had significant improvement in BI (n = 38, p = 0.005), but non-recovers did not (n = 14, p = 0.512). On, multivariate analysis, BI was significantly affected by MMSE, APOE, IL-1α, IL-6, LIF and TNF-α levels (p < 0.05) but not by delirium. Delirium in acutely admitted patients is associated with functional decline only in those who do not recover. Biological factors, rather that delirium itself, may be responsible for this.     

Rapid development of glycan-specific, broad, and potent anti-HIV-1 gp120 neutralizing antibodies in an R5 SIV/HIV chimeric virus infected macaque

It is widely believed that the induction of a broadly neutralizing antibody (bNAb) response will be a critical component of a successful vaccine against HIV. A significant fraction of HIV-infected individuals mount bNAb responses, providing support for the notion that such responses could be elicited through vaccination. Infection of macaques with simian immunodeficiency virus (SIV) or SIV/HIV chimeric virus (SHIV) has been widely used to model aspects of HIV infection, but to date, only limited bNAb responses have been described. Here, we screened plasma from 14 R5-tropic SHIV-infected macaques for broadly neutralizing activity and identified a macaque with highly potent cross-clade plasma NAb response. Longitudinal studies showed that the development of broad and autologous NAb responses occurred coincidentally in this animal. Serum-mapping studies, using pseudovirus point mutants and antigen adsorption assays, indicated that the plasma bNAbs are specific for epitopes that include carbohydrates and are critically dependent on the glycan at position 332 of Env gp120. The results described herein provide insight into the development and evolution of a broad response, suggest that certain bNAb specificities may be more rapidly induced by immunization than others, and provide a potential model for the facile study of the development of bNAb responses.     

Dramatic decrease in malaria transmission after large-scale indoor residual spraying with bendiocarb in Benin, an area of high resistance of Anopheles gambiae to pyrethroids

In 2008, the National Malaria Control Program in Benin implemented a vector control intervention based on indoor residual spraying (IRS). Four districts of high resistance of Anopheles gambiae to pyrethroids were sprayed with bendiocarb. More than 350,000 inhabitants have been protected. Entomologic parameters in the control area were compared with those in intervention sites. The study has shown a drastic decrease in the An. gambiae biting rate in the sprayed areas. Results of an enzyme-linked immunosorbent assay were negative for Plasmodium falciparum antigen during the entire period of the intervention. No household members received infected bites (entomologic inoculation rate = 0 during January-July). Parous rates were low in areas covered by IRS because bendiocarb is not conducive to long-term mosquito survival. Bendiocarb was found to be a good alternative insecticide for IRS in Benin, in areas where An. gambiae has developed high resistance to pyrethroids.