Detection of occult hepatitis B requires assays of the highest sensitivity and specificity with a lower limit of detection of less than 10 IU/mL for hepatitis B virus (HBV) DNA and <0.1 ng/mL for ...hepatitis B surface antigen (HBsAg). This covert condition is relatively common in patients with chronic hepatitis C virus (HCV) that seems to exert some influence on the replicative capacity and latency of HBV. Detection of virus‐specific nucleic acid does not always translate into infectivity, and the occurrence of primer‐generated HBV DNA that is of partial genomic length in immunocompetent individuals who have significant levels of hepatitis B surface antibody (anti‐HBs) may not be biologically relevant. Acute flares of alanine aminotransferase (ALT) that occur during the early phase of therapy for HCV or ALT levels that remain elevated at the end of therapy in biochemical nonresponders should prompt an assessment for occult hepatitis B. Similarly, the plasma from patients with chronic hepatitis C that is hepatitis B core antibody (anti‐HBc) positive (±anti‐HBs at levels of <100 mIU/mL) should be examined for HBV DNA with the most sensitive assay available. If a liver biopsy is available, immunostaining for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) should be contemplated and a portion of the sample tested for HBV DNA. This is another reason for optimal collection of a specimen (e.g. two passes with a 16‐guage needle under ultrasound guidance). Transmission of HBV to immunosuppressed orthotopic liver transplant recipients by donors with occult hepatitis B (OHB) will continue to occupy the interests of the transplant hepatologist. As patients with OHB may have detectable HBV DNA in serum, peripheral blood mononuclear cells (PBMC) and/or liver that can be reactivated following immunosuppression or intensive cytotoxic chemotherapy, the patient needs to be either monitored or treated depending on the pretreatment serological results such as an isolated anti‐HBc reaction or a detectable HBV DNA.
Bronchopulmonary Dysplasia (BPD) is the commonest morbidity in extremely preterm infants (PTIs). Risk factors for BPD have been described in the era before the widespread availability of non-invasive ...ventilation (NIV) in the delivery room (DR). The objective of this study is to identify risk factors for Moderate/Severe BPD in an era of widespread availability of NIV in the DR.
Detailed antenatal and postnatal data were abstracted for PTIs, 230/7–276/7 weeks GA. Multivariate logistic regression and classification and regression tree analyses (CART) identified predictors for the primary outcome of Moderate/Severe BPD.
Of 263 eligible infants, 59% had Moderate/Severe BPD. Moderate/Severe BPD was significantly associated with birthweight, gender, DR intubation and surfactant compared to No/Mild BPD. Of infants not intubated in the DR, 40% with No/Mild BPD and 80% with Moderate/Severe BPD received intubation by 48 hours (p < 0.05). Infants with Moderate/Severe BPD received longer duration of oxygen and mechanical (MV). On logistic regression, birthweight, gender, oxygen concentration, cumulative duration of oxygen and MV, surfactant, and blood transfusions predicted Moderate/Severe BPD. Both CART analysis and logistic regression showed duration of oxygen and MV to be the most important predictors for Moderate/Severe BPD.
In an era of increasing availability of NIV in the DR, lower birthweight, male gender, surfactant treatment, blood transfusions and respiratory support in the first 2–3 weeks after birth predict Moderate/Severe BPD with high sensitivity and specificity. The majority of these infants received intubation within 48 hours of birth (97%). These data suggest that early failures of NIV represent opportunities for improvement of NIV techniques and of non-invasive surfactant to avoid intubation in the first 48 hours. Furthermore, these risk factors may allow earlier identification of infants most likely to benefit from interventions to prevent or decrease severity of BPD.
Summary Near-infrared spectroscopy (NIRS) offers non-invasive, in-vivo, real-time monitoring of tissue oxygenation. Changes in regional tissue oxygenation as detected by NIRS may reflect the delicate ...balance between oxygen delivery and consumption. Originally used predominantly to assess cerebral oxygenation and perfusion perioperatively during cardiac and neurosurgery, and following head trauma, NIRS has gained widespread popularity in many clinical settings in all age groups including neonates. However, more studies are required to establish the ability of NIRS monitoring to improve patient outcomes, especially in neonates. This review provides a comprehensive description of the use of NIRS in neonates.
Summary
The incidence of retinopathy in patients with chronic hepatitis C treated with interferon‐based regimens has been variably reported in the literature. There is no consensus regarding ...ophthalmologic screening before and during treatment with interferon‐based therapy. To assess the incidence of retinopathy in patients with chronic hepatitis C being treated with interferon‐based regimens and estimate the rate of resolution. A systematic literature search was performed to locate all relevant publications. Pooled incidence of retinopathy was calculated in patients treated with interferon or pegylated interferon. We also estimated the rate of discontinuation of treatment and resolution after the treatment was stopped. A total of 21 studies fulfilled the inclusion criteria. The overall incidence of retinopathy using random effect model was 27.7% (95% confidence interval CI 20.9–34.5%). The pooled incidence of retinopathy in 10 studies that only used pegylated interferon was 20.9% (95% CI: 11.6–29.8). The incidence of retinopathy with pegylated interferon in diabetic and hypertensive patients (high‐risk group) was 65.32% and 50.7%, respectively. This was significantly higher compared with the incidence of retinopathy (11.7%) in patients without these risk factors. Overall pooled estimate for the resolution of retinopathy was 87% (95% CI 75.7–98.4%). The rate of discontinuation of treatment was 6.3%. The incidence of retinopathy with pegylated interferon in patients without hypertension and diabetes is low, but the risk is higher in patients with diabetes and hypertension. Routine pretreatment fundoscopic screening may not be warranted in all patients and can be limited to the patients with these risk factors.
To characterize phosphatidylcholine (PC) molecular species in serial gastric aspirates as biomarkers for lung maturity, delivery of aerosolized surfactant (AS), and need for intubation.
In a phase II ...clinical trial of aerosolized surfactant in preterm neonates with respiratory distress syndrome receiving noninvasive ventilation, infants received a maximum of 2 doses of nebulized beractant. Gastric aspirates were collected before and after each dose and were analyzed for PCs using liquid chromatography mass spectrometry.
Of 149 infants enrolled, gastric aspirates were obtained before (n = 91) and after (n = 94) dose 1, and before (n = 56) and after (n = 57) dose 2 of nebulized beractant. The mean ± SD values of birthweight, gestational age, and age at collection of baseline gastric aspirate were 1.7 ± 0.6 kg, 31.7 ± 2.8 weeks, and 5.5 ± 1.7 hours, respectively. The most abundant PC in beractant and gastric aspirates was PC(16:0/16:0). Advancing gestational age and number of antenatal corticosteroid doses predicted increased gastric aspirate PC(16:0/16:0), whereas maternal diabetes predicted a decrease. Several PCs increased significantly (P < .05) after nebulized beractant, consistent with effective aerosol delivery. Infants who received intubation within 72 hours of birth were more likely to have lower PC(16:0/16:0) levels in baseline gastric aspirates compared with those who did not (P = .024).
PC molecular species in gastric aspirates of preterm neonates are potentially novel and precise biomarkers to assess lung maturity, aerosol delivery, and need for endotracheal intubation.
To identify genetic variants associated with sepsis (early-onset and late-onset) using a genome-wide association (GWA) analysis in a cohort of extremely premature infants.
Previously generated GWA ...data from the Neonatal Research Network's anonymised genomic database biorepository of extremely premature infants were used for this study. Sepsis was defined as culture-positive early-onset or late-onset sepsis or culture-proven meningitis. Genomic and whole-genome-amplified DNA was genotyped for 1.2 million single-nucleotide polymorphisms (SNPs); 91% of SNPs were successfully genotyped. We imputed 7.2 million additional SNPs. p Values and false discovery rates (FDRs) were calculated from multivariate logistic regression analysis adjusting for gender, gestational age and ancestry. Target statistical value was p<10
. Secondary analyses assessed associations of SNPs with pathogen type. Pathway analyses were also run on primary and secondary end points.
Data from 757 extremely premature infants were included: 351 infants with sepsis and 406 infants without sepsis. No SNPs reached genome-wide significance levels (5×10
); two SNPs in proximity to FOXC2 and FOXL1 genes achieved target levels of significance. In secondary analyses, SNPs for ELMO1, IRAK2 (Gram-positive sepsis), RALA, IMMP2L (Gram-negative sepsis) and PIEZO2 (fungal sepsis) met target significance levels. Pathways associated with sepsis and Gram-negative sepsis included gap junctions, fibroblast growth factor receptors, regulators of cell division and interleukin-1-associated receptor kinase 2 (p values<0.001 and FDR<20%).
No SNPs met genome-wide significance in this cohort of extremely low birthweight infants; however, areas of potential association and pathways meriting further study were identified.
Background and Objectives
Bronchopulmonary dysplasia (BPD) is a serious complication of preterm birth, resulting in significant morbidity and mortality. Recent studies have suggested that microRNA ...(miRNA) dysregulation is involved in the pathogenesis of BPD and may serve as biomarkers for early detection. We conducted a directed search for dysregulated miRNAs in lung and heart autopsy samples of infants with histologic BPD.
Methods
We used archived lung and heart samples from BPD (13 lung, 6 heart) and control (24 lung, 5 heart) subjects. To measure miRNA expression, RNA was extracted from formalin‐fixed, paraffin‐embedded (FFPE) tissue specimens then reverse‐transcribed, labeled, and hybridized to miRNA microarrays. The microarrays were scanned, and data were quantile normalized. Statistical analysis with a moderated t‐test and control of the false discovery rate (5%) was used to compare normalized miRNA expression values between clinical categories.
Results
With our set of 48 samples, 43 miRNAs had a significant difference in expression comparing BPD to non‐BPD controls. Among the most statistically significant miRNAs, miR‐378b, miRNA‐184, miRNA‐3667‐5p, miRNA‐3976, miRNA‐4646‐5p, and miRNA‐7846‐3p were all consistently upregulated in both the heart and lung tissues of BPD subjects. The cellular pathway predicted to be most affected by these miRNAs is the Hippo signaling pathway.
Conclusions
This study identifies miRNAs that are similarly dysregulated in postmortem lung and heart samples in subjects with histologic BPD. These miRNAs may contribute to the pathogenesis of BPD, have potential as biomarkers, and may provide insight to novel approaches for diagnosis and treatment.
The endothelial nitric-oxide synthase (eNOS) is regulated in part by serine/threonine phosphorylation, but eNOS tyrosine phosphorylation is less well understood. In the present study we have examined ...the tyrosine phosphorylation of eNOS in bovine aortic endothelial cells (BAECs) exposed to oxidant stress. Hydrogen peroxide and pervanadate (PV) treatment stimulates eNOS tyrosine phosphorylation in BAECs. Phosphorylation is blocked by the Src kinase family inhibitor, 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo3,4-dpyrimidine (PP2). Moreover, eNOS and c-Src can be coimmunoprecipitated from BAEC lysates by antibodies directed against either protein. Domain mapping and site-directed mutagenesis studies in COS-7 cells transfected with either eNOS alone and then treated with PV or cotransfected with eNOS and constitutively active v-Src identified Tyr-83 (bovine sequence) as the major eNOS tyrosine phosphorylation site. Tyr-83 phosphorylation is associated with a 3-fold increase in basal NO release from cotransfected cells. Furthermore, the Y83F eNOS mutation attenuated thapsigargin-stimulated NO production. Taken together, these data indicate that Src-mediated tyrosine phosphorylation of eNOS at Tyr-83 modulates eNOS activity in endothelial cells.
3-Hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors, statins, provide beneficial effects independent of their lipid-lowering effects. One beneficial effect appears to involve acute activation ...of endothelial nitric oxide (NO) synthase (eNOS) and increased NO release. However, the mechanism of acute statin-stimulated eNOS activation is unknown. Therefore, we hypothesized that eNOS activation may be coupled to altered eNOS phosphorylation. Bovine aortic endothelial cells (BAECs), passages 2-6, were treated with either lovastatin or pravastatin from 0 to 30 min. eNOS phosphorylation was examined by Western blot by use of phosphospecific antibodies for Ser-1179, Ser-635, Ser-617, Thr-497, and Ser-116. Statin stimulation of BAECs increased eNOS phosphorylation at Ser-1179 and Ser-617, which was blocked by the phosphatidylinositol 3-kinase (PI3-kinase)/Akt inhibitor wortmannin, and at Ser-635, which was blocked by the protein kinase A (PKA) inhibitor KT-5720. Statin treatment of BAECs transiently increased NO release by fourfold, measured by cGMP accumulation, and was attenuated by N-nitro-l-arginine methyl ester, wortmannin, and KT-5720 but not by mevalonate. In conclusion, these data demonstrate that eNOS is acutely activated by statins independent of HMG-CoA reductase inhibition and that in addition to Ser-1179, eNOS phosphorylation at Ser-635 and Ser-617 through PKA and Akt, respectively, may explain, in part, a mechanism by which eNOS is activated in response to acute statin treatment.
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