Is there evidence of fetal-maternal heart rate synchronization?

Background

The prenatal condition offers a unique possibility of examining physiological interaction between individuals. Goal of this work was to look for evidence of coordination between fetal and maternal cardiac systems.

Methods

177 magnetocardiograms were recorded in 62 pregnancies (16^th–42^nd week of gestation). Fetal and maternal RR interval time series were constructed and the phases, i.e. the timing of the R peaks of one time series in relation to each RR interval of the other were determined. The distributions of these phases were examined and synchrograms were constructed for real and surrogate pairs of fetal and maternal data sets. Synchronization epochs were determined for defined n:m coupling ratios.

Results

Differences between real and surrogate data could not be found with respect to number of synchronization epochs found (712 vs. 741), gestational age, subject, recording or n:m combination. There was however a preference for the occurrence of synchronization epochs in specific phases in real data not apparent in the surrogate for some n:m combinations.

Conclusion

The results suggest that occasional coupling between fetal and maternal cardiac systems does occur.

     

Identification of a gammaherpesvirus selective chemokine binding protein that inhibits chemokine action

Chemokines are involved in recruitment and activation of hematopoietic cells at sites of infection and inflammation. The M3 gene of gammaHV68, a gamma-2 herpesvirus that infects and establishes a lifelong latent infection and chronic vasculitis in mice, encodes an abundant secreted protein during productive infection. The M3 gene is located in a region of the genome that is transcribed during latency. We report here that the M3 protein is a high-affinity broad-spectrum chemokine scavenger. The M3 protein bound the CC chemokines human regulated upon activation of normal T-cell expressed and secreted (RANTES), murine macrophage inflammatory protein 1alpha (MIP-1alpha), and murine monocyte chemoattractant protein 1 (MCP-1), as well as the human CXC chemokine interleukin-8, the murine C chemokine lymphotactin, and the murine CX(3)C chemokine fractalkine with high affinity (K(d) = 1. 6 to 18.7 nM). M3 protein chemokine binding was selective, since the protein did not bind seven other CXC chemokines (K(d) > 1 microM). Furthermore, the M3 protein abolished calcium signaling in response to murine MIP-1alpha and murine MCP-1 and not to murine KC or human stromal cell-derived factor 1 (SDF-1), consistent with the binding data. The M3 protein was also capable of blocking the function of human CC and CXC chemokines, indicating the potential for therapeutic applications. Since the M3 protein lacks homology to known chemokines, chemokine receptors, or chemokine binding proteins, these studies suggest a novel herpesvirus mechanism of immune evasion.     

Complete genome sequence of the extremely acidophilic methanotroph isolate V4, Methylacidiphilum infernorum, a representative of the bacterial phylum Verrucomicrobia

Background

The phylum Verrucomicrobia is a widespread but poorly characterized bacterial clade. Although cultivation-independent approaches detect representatives of this phylum in a wide range of environments, including soils, seawater, hot springs and human gastrointestinal tract, only few have been isolated in pure culture. We have recently reported cultivation and initial characterization of an extremely acidophilic methanotrophic member of the Verrucomicrobia, strain V4, isolated from the Hell's Gate geothermal area in New Zealand. Similar organisms were independently isolated from geothermal systems in Italy and Russia.

Results

We report the complete genome sequence of strain V4, the first one from a representative of the Verrucomicrobia. Isolate V4, initially named "Methylokorus infernorum" (and recently renamed Methylacidiphilum infernorum) is an autotrophic bacterium with a streamlined genome of ~2.3 Mbp that encodes simple signal transduction pathways and has a limited potential for regulation of gene expression. Central metabolism of M. infernorum was reconstructed almost completely and revealed highly interconnected pathways of autotrophic central metabolism and modifications of C₁-utilization pathways compared to other known methylotrophs. The M. infernorum genome does not encode tubulin, which was previously discovered in bacteria of the genus Prosthecobacter, or close homologs of any other signature eukaryotic proteins. Phylogenetic analysis of ribosomal proteins and RNA polymerase subunits unequivocally supports grouping Planctomycetes, Verrucomicrobia and Chlamydiae into a single clade, the PVC superphylum, despite dramatically different gene content in members of these three groups. Comparative-genomic analysis suggests that evolution of the M. infernorum lineage involved extensive horizontal gene exchange with a variety of bacteria. The genome of M. infernorum shows apparent adaptations for existence under extremely acidic conditions including a major upward shift in the isoelectric points of proteins.

Conclusion

The results of genome analysis of M. infernorum support the monophyly of the PVC superphylum. M. infernorum possesses a streamlined genome but seems to have acquired numerous genes including those for enzymes of methylotrophic pathways via horizontal gene transfer, in particular, from Proteobacteria.

Reviewers

This article was reviewed by John A. Fuerst, Ludmila Chistoserdova, and Radhey S. Gupta.     

Macrophages are the major reservoir of latent murine gammaherpesvirus 68 in peritoneal cells

B cells have previously been identified as the major hematopoietic cell type harboring latent gammaherpesvirus 68 (gammaHV68) (N. P. Sunil-Chandra, S. Efstathiou, and A. A. Nash, J. Gen. Virol. 73:3275-3279, 1992). However, we have shown that gammaHV68 efficiently establishes latency in B-cell-deficient mice (K. E. Weck, M. L. Barkon, L. I. Yoo, S. H. Speck, and H. W. Virgin, J. Virol. 70:6775-6780, 1996), demonstrating that B cells are not required for gammaHV68 latency. To understand this dichotomy, we determined whether hematopoietic cell types, in addition to B cells, carry latent gammaHV68. We observed a high frequency of cells that reactivate latent gammaHV68 in peritoneal exudate cells (PECs) derived from both B-cell-deficient and normal C57BL/6 mice. PECs were composed primarily of macrophages in B-cell-deficient mice and of macrophages plus B cells in normal C57BL/6 mice. To determine which cells in PECs from C57BL/6 mice carry latent gammaHV68, we developed a limiting-dilution PCR assay to quantitate the frequency of cells carrying the gammaHV68 genome in fluorescence-activated cell sorter-purified cell populations. We also quantitated the contribution of individual cell populations to the total frequency of cells carrying latent gammaHV68. At early times after infection, the frequency of PECs that reactivated gammaHV68 correlated very closely with the frequency of PECs carrying the gammaHV68 genome, validating measurement of the frequency of viral-genome-positive cells as a measure of latency in this cell population. F4/80-positive macrophage-enriched, lymphocyte-depleted PECs harbored most of the gammaHV68 genome and efficiently reactivated gammaHV68, while CD19-positive, B-cell-enriched PECs harbored about a 10-fold lower frequency of gammaHV68 genome-positive cells. CD4-positive, T-cell-enriched PECs contained only a very low frequency of gammaHV68 genome-positive cells, consistent with previous analyses indicating that T cells are not a reservoir for gammaHV68 latency (N. P. Sunil-Chandra, S. Efstathiou, and A. A. Nash, J. Gen. Virol. 73:3275-3279, 1992). Since macrophages are bone marrow derived, we determined whether elicitation of a large inflammatory response in the peritoneum would recruit additional latent cells into the peritoneum. Thioglycolate inoculation increased the total number of PECs by about 20-fold but did not affect the frequency of cells that reactivate gammaHV68, consistent with a bone marrow reservoir for latent gammaHV68. These experiments demonstrate gammaHV68 latency in two different hematopoietic cell types, F4/80-positive macrophages and CD19-positive B cells, and argue for a bone marrow reservoir for latent gammaHV68.     

Provisional stenting in the real world: results in 1058 consecutive patients undergoing percutaneous coronary angioplasty

OBJECTIVE: To study a strategy of aggressive coronary balloon angioplasty with provisional stenting in allcomers. In randomized trials, stenting has improved the outcome of patients undergoing coronary intervention. However, whether these results hold up in clinical practice is largely unknown. Furthermore, the results of balloon angioplasty have also improved dramatically. It is therefore essential to evaluate the current results of balloon angioplasty and to assess whether stents are required in all patients. METHODS: The authors prospectively studied the occurrence of death, myocardial infarction (MI) and target lesion revascularization (TLR) of a large consecutive group of patients undergoing aggressive balloon angioplasty with provisional stenting. None of the patients received a platelet glycoprotein IIb/IIIa receptor blocker. The results were compared with the outcome of routine stenting in recent randomized trials. RESULTS: Angioplasty was performed in 1058 patients of whom 369 (34.9%) received a stent. The angiographic success rate was 98.9%. During hospital stay, 4.8% of the patients suffered any cardiac event. At one-year follow-up, death occurred in 1.1%, MI in 3.3%, TLR in 12.4% and any event in 16.7% of the patients. Event-free survival at one-year was 82.3%. These results compare favorably with routine stenting in recent trials. CONCLUSIONS: Aggressive balloon angioplasty with provisional stenting yields excellent results in a general patient population.     

Antiplatelet and anticoagulant therapy in elective percutaneous coronary intervention

Thrombosis plays a major role in acute vessel closure both after coronary balloon angioplasty and after stenting. This review will address the role of antiplatelet and anticoagulant therapy in preventing early thrombotic complications after percutaneous coronary intervention. The focus will be on agents that are routinely available and commonly used.     

Characterisation of<Emphasis Type="Italic">fusarium graminearum</Emphasis> and<Emphasis Type="Italic">F. culmorum</Emphasis> isolates by mycotoxin production and aggressiveness to wheat

A total of 27Fusarium culmorum isolates from Germany and 41F. graminearum isolates from Kenya were investigated for aggressiveness and mycotoxin production on wheat ears. In addition, ergosterol content of the kernels from ears inoculated withF. graminearum was determined and theF. culmorum isolates were tested for mycotoxin productionin vitro. For both pathogens, isolates markedly differed in aggressiveness. 59% and 37% of theF. culmorum isolates produced NIV and DON, respectively,in vivo andin vitro. The DON-producing isolates also produced 3-acDONin vitro. The more aggressive isolates produced mainly DON while the less aggressive isolates produced mainly NIV. 12% and 85% of theF. graminearum isolates produced NIV and DON, respectively. The highly aggressive isolates produced higher amounts of DON, aggressiveness being highly correlated to DON content in the kernels. NIV-producing isolates were less aggressive. Ergosterol content of kernels was moderately correlated to aggressiveness but highly correlated to DON content. Disease severity was associated with kernel weight reduction.