Prevalence and characteristics of gastroesophageal reflux disease in pregnant women.

INTRODUCTION AND AIMS: The prevalence of gastroesophageal reflux disease (GERD) has been reported to be increasing in recent years. However, there have been few reports on the prevalence of GERD during pregnancy in the Asian population. The aim of our study was to evaluate the prevalence and characteristics of GERD in Vietnamese pregnant women. MATERIALS AND METHODS: This cross-sectional study was conducted at the antenatal clinic of the Nhan Dan Gia Dinh Hospital, Ho Chi Minh, Vietnam. Four hundred females, at various stages of pregnancy, were enrolled. GERD was diagnosed if there was troublesome heartburn and/or acid regurgitation, at least once a week, during the current pregnancy. RESULTS: The overall prevalence of GERD in pregnancy was 38.5% (154/400). The prevalence of GERD in the third trimester was significantly higher than that in the second trimester (46.8% vs. 30.7%, P=0.008) and tended to be higher than its prevalence in the first trimester (46.8% vs. 35.4%, P=0.051). In the pregnant women with GERD, the frequency of regurgitation was significantly higher than that of heartburn (92.9% vs. 30.5%, P<0.001). Those typical symptoms were more prevalent in the daytime, compared with nighttime. CONCLUSION: Our study showed that GERD was prevalent during pregnancy in Vietnam. In the pregnant women with GERD, regurgitation was much more common than heartburn, and those typical reflux symptoms occurred more frequently in the daytime, compared with nighttime.

Chrysosplenol-C Increases Contraction by Augmentation of Sarcoplasmic Reticulum Ca2+ Loading and Release via Protein Kinase C in Rat Ventricular Myocytes.

Naturally found chrysosplenol-C (4',5,6-trihydroxy-3,3',7-trimethoxyflavone) increases the contractility of cardiac myocytes independent of ß-adrenergic signaling. We investigated the cellular mechanism for chrysosplenol-C-induced positive inotropy. Global and local Ca2+ signals, L-type Ca2+ current (ICa), and contraction were measured from adult rat ventricular myocytes using two-dimensional confocal Ca2+ imaging, the whole-cell patch-clamp technique, and video-edge detection, respectively. Application of chrysosplenol-C reversibly increased Ca2+ transient magnitude with a maximal increase of ∼55% within 2- to 3-minute exposures (EC50 ≅ 21 µM). This chemical did not alter ICa and slightly increased diastolic Ca2+ level. The frequency and size of resting Ca2+ sparks were increased by chrysosplenol-C. Chrysosplenol-C significantly increased sarcoplasmic reticulum (SR) Ca2+ content but not fractional release. Pretreatment of protein kinase C (PKC) inhibitor but not Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor abolished the stimulatory effects of chrysosplenol-C on Ca2+ transients and Ca2+ sparks. Chrysosplenol-C-induced positive inotropy was removed by the inhibition of PKC but not CaMKII or phospholipase C. Western blotting assessment revealed that PKC-δ protein level in the membrane fractions significantly increase within 2 minutes after chrysosplenol-C exposure with a delayed (5-minute) increase in PKC-α levels in insoluble membrane. These results suggest that chrysosplenol-C enhances contractility via PKC (most likely PKC-δ)-dependent enhancement of SR Ca2+ releases in ventricular myocytes. SIGNIFICANCE STATEMENT: Study shows that chrysosplenol-C, a natural flavone showing a positive inotropic effect, increases SR Ca2+ releases on depolarizations and Ca2+ sparks with an increase of SR Ca2+ loading but not L-type Ca2+ current in ventricular myocytes. Chrysosplenol-C-induced enhancement in contraction is eliminated by PKC inhibition, and it is associated with redistributions of PKC to the membrane. These indicate that chrysosplenol-C enhances contraction via PKC-dependent augmentations of SR Ca2+ release and Ca2+ loading during action potentials.

Molecular Architecture of Early Dissemination and Massive Second Wave of the SARS-CoV-2 Virus in a Major Metropolitan Area.

We sequenced the genomes of 5,085 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains causing two coronavirus disease 2019 (COVID-19) disease waves in metropolitan Houston, TX, an ethnically diverse region with 7 million residents. The genomes were from viruses recovered in the earliest recognized phase of the pandemic in Houston and from viruses recovered in an ongoing massive second wave of infections. The virus was originally introduced into Houston many times independently. Virtually all strains in the second wave have a Gly614 amino acid replacement in the spike protein, a polymorphism that has been linked to increased transmission and infectivity. Patients infected with the Gly614 variant strains had significantly higher virus loads in the nasopharynx on initial diagnosis. We found little evidence of a significant relationship between virus genotype and altered virulence, stressing the linkage between disease severity, underlying medical conditions, and host genetics. Some regions of the spike protein-the primary target of global vaccine efforts-are replete with amino acid replacements, perhaps indicating the action of selection. We exploited the genomic data to generate defined single amino acid replacements in the receptor binding domain of spike protein that, importantly, produced decreased recognition by the neutralizing monoclonal antibody CR3022. Our report represents the first analysis of the molecular architecture of SARS-CoV-2 in two infection waves in a major metropolitan region. The findings will help us to understand the origin, composition, and trajectory of future infection waves and the potential effect of the host immune response and therapeutic maneuvers on SARS-CoV-2 evolution.IMPORTANCE There is concern about second and subsequent waves of COVID-19 caused by the SARS-CoV-2 coronavirus occurring in communities globally that had an initial disease wave. Metropolitan Houston, TX, with a population of 7 million, is experiencing a massive second disease wave that began in late May 2020. To understand SARS-CoV-2 molecular population genomic architecture and evolution and the relationship between virus genotypes and patient features, we sequenced the genomes of 5,085 SARS-CoV-2 strains from these two waves. Our report provides the first molecular characterization of SARS-CoV-2 strains causing two distinct COVID-19 disease waves.

Molecular Architecture of Early Dissemination and Massive Second Wave of the SARS-CoV-2 Virus in a Major Metropolitan Area.

We sequenced the genomes of 5,085 SARS-CoV-2 strains causing two COVID-19 disease waves in metropolitan Houston, Texas, an ethnically diverse region with seven million residents. The genomes were from viruses recovered in the earliest recognized phase of the pandemic in Houston, and an ongoing massive second wave of infections. The virus was originally introduced into Houston many times independently. Virtually all strains in the second wave have a Gly614 amino acid replacement in the spike protein, a polymorphism that has been linked to increased transmission and infectivity. Patients infected with the Gly614 variant strains had significantly higher virus loads in the nasopharynx on initial diagnosis. We found little evidence of a significant relationship between virus genotypes and altered virulence, stressing the linkage between disease severity, underlying medical conditions, and host genetics. Some regions of the spike protein - the primary target of global vaccine efforts - are replete with amino acid replacements, perhaps indicating the action of selection. We exploited the genomic data to generate defined single amino acid replacements in the receptor binding domain of spike protein that, importantly, produced decreased recognition by the neutralizing monoclonal antibody CR30022. Our study is the first analysis of the molecular architecture of SARS-CoV-2 in two infection waves in a major metropolitan region. The findings will help us to understand the origin, composition, and trajectory of future infection waves, and the potential effect of the host immune response and therapeutic maneuvers on SARS-CoV-2 evolution.

Development and Evaluation of a Novel Protein-Based Assay for Specific Detection of KPC ß-Lactamases from Klebsiella pneumoniae Clinical Isolates.

Carbapenemases confer resistance to nearly all ß-lactam antibiotics. The extensive spread of carbapenemase-producing multidrug-resistant bacteria contributes significantly to hospital-acquired infections. We have developed a novel protein-based binding assay that identifies KPC ß-lactamases from clinical isolates. We used the protein-protein interaction between KPCs and a soluble ß-lactamase inhibitory protein (BLIP) variant, BLIPK74T/W112D, which specifically inhibits KPCs but not other ß-lactamases. In this assay, BLIPK74T/W112D was allowed to form complexes with KPC-2 in bacterial cell lysates and then extracted using His tag binding resins. We demonstrated the presence of KPC-2 by monitoring the hydrolysis of a colorimetric ß-lactam substrate. Also, to further increase the accuracy of the method, a BLIPK74T/W112D-mediated inhibition assay was developed. The binding and inhibition assays were validated by testing 127 Klebsiella pneumoniae clinical isolates with known genome sequences for the presence of KPC. Our assays identified a total of 32 strains as KPC-2 producers, a result in 100% concordance with genome sequencing predictions. To further simplify the assay and decrease the time to obtain results, the BLIPK74T/W112D protein was tested in combination with the widely used Carba-NP assay. For this purpose, the genome-sequenced K. pneumoniae strains were tested for the presence of carbapenemases with the Carba-NP test with and without the addition of BLIPK74T/W122D The test accurately identified carbapenemase-producing strains and the addition of BLIPK74T/W112D allowed a further determination that the strains contain KPC carbapenemase. Thus, the BLIPK74T/W112D protein is an effective sensor to specifically detect KPC ß-lactamases produced by clinical isolates.IMPORTANCE Infections caused by carbapenem-resistant Enterobacteriaceae are associated with high therapeutic failure and mortality rates. Thus, it is critical to rapidly identify clinical isolates expressing KPC ß-lactamases to facilitate administration of the correct antibiotic treatment and initiate infection control strategies. To address this problem, we developed a protein-based, KPC-specific binding assay in combination with a cell lysate inhibition assay that provided a 100% identification rate of KPC from clinical isolates of known genomic sequence. In addition, this protein sensor was adapted to the Carba-NP assay to provide a rapid strategy to detect KPC-producing isolates that will facilitate informed treatment of critically ill patients.

Draft Genome Sequence of Candida auris Strain LOM, a Human Clinical Isolate from Greater Metropolitan Houston, Texas.

Candida auris is an emerging pathogen of considerable public health importance. We present the draft genome sequence of a strain recently cultured from the urine of a patient hospitalized in the greater Houston metropolitan region. Two combined Oxford Nanopore sequencing runs provided sufficient data to rapidly generate a draft genome.

Integrated analysis of population genomics, transcriptomics and virulence provides novel insights into Streptococcus pyogenes pathogenesis.

Streptococcus pyogenes causes 700 million human infections annually worldwide, yet, despite a century of intensive effort, there is no licensed vaccine against this bacterium. Although a number of large-scale genomic studies of bacterial pathogens have been published, the relationships among the genome, transcriptome, and virulence in large bacterial populations remain poorly understood. We sequenced the genomes of 2,101 emm28 S. pyogenes invasive strains, from which we selected 492 phylogenetically diverse strains for transcriptome analysis and 50 strains for virulence assessment. Data integration provided a novel understanding of the virulence mechanisms of this model organism. Genome-wide association study, expression quantitative trait loci analysis, machine learning, and isogenic mutant strains identified and confirmed a one-nucleotide indel in an intergenic region that significantly alters global transcript profiles and ultimately virulence. The integrative strategy that we used is generally applicable to any microbe and may lead to new therapeutics for many human pathogens.

Metal-insulator transitions in the half-filled ionic Hubbard model.

We study electronic phase transitions in the half-filled ionic Hubbard model with an on-site Coulomb repulsion U and an ionic energy Δ by using the coherent potential approximation. For a fixed and finite Δ two transitions from the band insulator via a metallic state to a Mott insulator are found with increasing U. The values of the critical correlation-driven metal-insulator transitions U(c1)(Δ) and U(c2)(Δ) are estimated. Our results are in reasonable agreement with the ones obtained by single-site dynamical mean-field theory and determinant quantum Monte Carlo simulation.

Collaboration, cholera, and cyclones: a project to improve point-of-use water quality in Madagascar.

In November 1999, CARE Madagascar, Population Services International (PSI), and the Centers for Disease Control and Prevention (CDC) selected 30 poor communities in urban Antananarivo as the target population for launch of the Safe Water System. The system consists of behavior change techniques along with point-of-use treatment and safe storage of water. The project was launched in March 2000, ahead of schedule, because a cholera epidemic struck Madagascar in January. Because of the enormous demand created by the cholera epidemic and by 3 cyclones that followed in the next 3 months, the project grew to national scale in less than a year. The combination of community mobilization and social marketing resulted in increased demand for and use of the Safe Water System.

A novel association between the human heat shock transcription factor 1 (HSF1) and prostate adenocarcinoma.

A search for differentially expressed genes in a pair of nonmetastatic (PC-3) versus metastatic variant (PC-3M) human prostate carcinoma cell lines led to identification of the human heat shock factor (HSF1) as an overexpressed gene product in PC-3M cells. Analysis of primary prostate cancer specimens indicated that HSF1 is generally up-regulated in most of the malignant prostate epithelial cells relative to the normal prostate cells. Among the known effectors of HSF1 action, constitutive levels of HSP70 and HSP90 are not significantly altered by the naturally elevated expression of HSF1 as in PC-3M cells or by transduced overexpression of HSF1 in PC-3 cells. The basal levels of HSP27 in both cases are, however, consistently increased by two- to threefold. With respect to response to heat shock, high basal concentration of HSP90 is not further enhanced in these cells, and HSP70 is up-regulated irrespective of HSF1 level. Heat shock, however, causes an increase in HSP27 when HSF1 is up-regulated, except when the expression of HSF1 is already too high. These results document for the first time that HSF1 is overexpressed in human prostate cancer cells, at least one consequence of which in the prostate cancer cell lines tested is stimulation of both basal and stress-induced expression of HSP27, an important factor in cell growth, differentiation, or apoptosis.

Current management of human bites.

Human bites should be considered dangerous injuries with potentially serious complications. Their characteristics vary from an uninfected abrasion to a serious infection such as cellulitis or osteomyelitis. An estimated 10% of the injuries become infected; suspected pathogens include oral and skin flora. Management consists of history and examination, wound care, surgical intervention if necessary, assessment of risk of disease transmission, and appropriate antibiotic prophylaxis or treatment. The best choice for oral or intravenous antibiotic therapy remains the combination of a beta-lactam antibiotic with a beta-lactamase inhibitor. Among the most serious human bites are clenched fist injuries, which often require surgical intervention and intravenous antibiotic therapy.

Downregulation of human FGF8 activity by antisense constructs in murine fibroblastic and human prostatic carcinoma cell systems.

Previously, we described cloning of three alternatively spliced mRNA forms of human FGF8, a, b, and e, of which the b form is the major expressed species in both normal and tumor prostatic epithelial cells. In this report, we describe construction and overexpression of sense and antisense sequences of either the full length FGF8b coding region (215-amino acids or 215aa), 103aa N-terminal part or a smaller N-terminal region (34aa), each including the 23aa putative signal peptide domain, via a retrovirus system. While the morphologic transforming activities of the sense 215aa and 103aa constructs were similar in NIH3T3 cells, 103aa displayed reduced soft agar clonogenic activity. The 34aa construct was practically inert in these assays, although its expression could mimic the ability of 215aa or 103aa in conferring cell growth under reduced serum condition. Overexpression of any of the three constructs in antisense orientation, however, was similarly effective in reversing the morphology and anchorage-independent growth property of FGF8b-transfected NIH3T3 cells. The expression of the antisense 215aa construct significantly reduced the growth rate of the human prostatic carcinoma DU145 cells and inhibited their soft agar clonogenic activity and in vivo tumorigenicity in nude mice. Taken together, these results identify N-terminal portions of FGF8 protein isoform for having the domains necessary for one or more of the biologic effects examined, and suggest that low levels of FGF8 expressed in prostatic epithelial cells may contribute significantly to their growth and tumorigenic properties.

17beta-estradiol inhibits apoptosis of endothelial cells.

Endothelial cells provide an antithrombotic and anti-inflammatory barrier for the normal vessel wall. Dysfunction of endothelial cells has been shown to promote atherosclerosis, and normalization of previously dysfunctional endothelial cells can inhibit the genesis of atheroma. In normal arteries, endothelial cells are remarkably quiescent. Acceleration of the turnover rate of endothelial cells can lead to their dysfunction. Apoptosis is a physiological process that contributes to vessel homeostasis, by eliminating damaged cells from the vessel wall. However, increased endothelial cell turnover mediated through accelerated apoptosis may alter the function of the endothelium and therefore, promote atherosclerosis. Apoptotic endothelial cells can be detected on the luminal surface of atherosclerotic coronary vessels, but not in normal vessels. This finding links endothelial cell apoptosis and the process of atherosclerosis, although a causative role for apoptosis in this process remains hypothetical. Estrogen metabolites have been shown to be among the most potent anti-atherogenic agents available to date for post-menopausal women. The mechanism of estrogen's protective effect is currently incompletely characterized. Here we show that 17beta-estradiol, a key estrogen metabolite, inhibits apoptosis in cultured endothelial cells. Our data support the hypothesis that 17beta-estradiol's anti-apoptotic effect may be mediated via improved endothelial cell interaction with the substratum, increased tyrosine phosphorylation of pp125 focal adhesion kinase, and a subsequent reduction in programmed cell death of endothelial cells. Inhibition of apoptosis by estrogens may account for some of the anti-atherogenic properties of these compounds.

A link between increased transforming activity of lymphoma-derived MYC mutant alleles, their defective regulation by p107, and altered phosphorylation of the c-Myc transactivation domain.

The c-Myc protein is a transcription factor with an N-terminal transcriptional regulatory domain and C-terminal oligomerization and DNA-binding motifs. Previous studies have demonstrated that p107, a protein related to the retinoblastoma protein, binds to the c-Myc transcriptional activation domain and suppresses its activity. We sought to characterize the transforming activity and transcriptional properties of lymphoma-derived mutant MYC alleles. Alleles encoding c-Myc proteins with missense mutations in the transcriptional regulatory domain were more potent than wild-type c-Myc in transforming rodent fibroblasts. Although the mutant c-Myc proteins retained their binding to p107 in in vitro and in vivo assays, p107 failed to suppress their transcriptional activation activities. Many of the lymphoma-derived MYC alleles contain missense mutations that result in substitution for the threonine at codon 58 or affect sequences flanking this amino acid. We observed that in vivo phosphorylation of Thr-58 was absent in a lymphoma cell line with a mutant MYC allele containing a missense mutation flanking codon 58. Our in vitro studies suggest that phosphorylation of Thr-58 in wild-type c-Myc was dependent on cyclin A and required prior phosphorylation of Ser-62 by a p107-cyclin A-CDK complex. In contrast, Thr-58 remained unphosphorylated in two representative mutant c-Myc transactivation domains in vitro. Our studies suggest that missense mutations in MYC may be selected for during lymphomagenesis, because the mutant MYC proteins have altered functional interactions with p107 protein complexes and fail to be phosphorylated at Thr-58.

Cyclin A links c-Myc to adhesion-independent cell proliferation.

Adhesion-independent growth is a neoplastic phenotype that is inducible in Rat 1a fibroblasts by enforced MYC expression. The c-Myc protein has been well characterized as a transcription factor, yet the molecular basis of c-Myc-induced neoplastic transformation has remained elusive. In this report, we demonstrate a link between ectopic MYC expression, deregulated cyclin A levels, and adhesion-independent growth.

Participation of cyclin A in Myc-induced apoptosis.

The involvement of c-Myc in cellular proliferation or apoptosis has been linked to differential cyclin gene expression. We observed that in both proliferating cells and cells undergoing apoptosis, cyclin A (but not B, C, D1, and E) mRNA level was elevated in unsynchronized Myc-overexpressing cells when compared with parental Rat1a fibroblasts. We further demonstrated that Zn(2+)-inducible cyclin A expression was sufficient to cause apoptosis. When Myc-induced apoptosis was blocked by coexpression of Bcl-2, the levels of cyclin C, D1, and E mRNAs were also elevated. Thus, while apoptosis induced by c-Myc is associated with an elevated cyclin A mRNA level, protection from apoptosis by coexpressed Bcl-2 is associated with a complementary increase in cyclin C, D1, and E mRNAs.

Transcriptional control of human Tenon's capsule fibroblast collagen synthesis in vitro by gamma-interferon.

PURPOSE: Gamma-interferon (gamma-IFN) has been shown to be a potent inhibitor of collagenous protein production independent of its effects on noncollagenous protein production and cell proliferation in vitro. To understand further the processes controlling tissue fibrosis and the potential use of gamma-IFN as an antifibrotic treatment after glaucoma filtering surgery, the in vitro effects of recombinant gamma-IFN on procollagen mRNA production were studied. METHODS: Subconfluent human Tenon's capsule fibroblast cultures were exposed to 10, 50, 500, and 1000 U/ml of human recombinant gamma-IFN for 48 hours and to 500 U/ml for 12, 24, and 72 hours. After the incubation period, polyA+ mRNAs were isolated by oligo (dT) cellulose columns, separated according to size by electrophoresis through a denaturing agarose gel, and transferred to an activated nylon membrane for Northern blot analysis. The levels of type III (alpha 1) procollagen, type I (alpha 1) procollagen, and fibronectin (noncollagenous protein) mRNA were determined by hybridization with radiolabeled cDNA probes specific for these components followed by autoradiography. RESULTS: Densitometric analysis showed gamma-IFN selectively inhibited type III and type I procollagen mRNA synthesis from 24% (10 U/ml) to 99% (1000 U/ml) while leaving fibronectin mRNA synthesis unaffected. The degree of inhibition was also time dependent; more inhibition occurred with increasing incubation time. CONCLUSIONS: These results indicate that gamma-IFN is able to regulate collagen synthesis at the transcriptional level and that its inhibition is relatively specific. Gamma-interferon's specific inhibitory effects may offer advantages over current therapies in modulating the fibrotic response after glaucoma filtering surgery.

The replication activation potential of selected RNA polymerase II promoter elements at the simian virus 40 origin.

Binding sites for cellular transcription factors were placed near the simian virus 40 origin of replication, and their effect on replication and TATA-dependent transcription was measured in COS cells. The hierarchy of transcriptional stimulation changed when the plasmids replicated. Only one of seven inserted sequences, a moderately weak transcription element, stimulated replication detectably. However, when two nonstimulatory sites were present in multiple copies they did activate replication. Multiple sites for the chimeric activator GAL4-VP16 did not stimulate replication even though transcription was stimulated strongly. The results indicate that the ability of a binding site to stimulate replication from the simian virus 40 ori is not based on its transcriptional activation potential but is instead related to a separate replication activation potential that can be increased by having multiple sites.

Transposition of Tn1000: in vivo properties.

Transposition mediated by the Tn1000 transposase was investigated by using transposon variants carrying synthetic or wild-type termini but no intact Tn1000 genes. Transposon Tn1001, whose only homologies to Tn1000 are in its 38-base-pair terminal inverted repeats, transposed at the same rate as Tn1005, an artificial construct carrying wild-type Tn1000 termini and approximately 1 kilobase of flanking Tn1000 DNA at each end, when transposase was supplied in trans. The majority of the transpositions into pOX38 gave rise to cointegrates, but approximately 10% of the products expressed phenotypes of direct transpositions. The expression and temperature dependence of the tnpA gene product were examined by studying transposition of Tn1001 to bacteriophage lambda. The temperature optimum for transposition was 37 degrees C, and the transposase was stable for up to 2 h at this temperature.