Survival of Male Patients with Incontinentia Pigmenti Carrying a Lethal Mutation Can Be Explained by Somatic Mosaicism or Klinefelter Syndrome

Incontinentia pigmenti (IP), or "Bloch-Sulzberger syndrome," is an X-linked dominant disorder characterized by abnormalities of skin, teeth, hair, and eyes; skewed X-inactivation; and recurrent miscarriages of male fetuses. IP results from mutations in the gene for NF-kappaB essential modulator (NEMO), with deletion of exons 4-10 of NEMO accounting for >80% of new mutations. Male fetuses inheriting this mutation and other "null" mutations of NEMO usually die in utero. Less deleterious mutations can result in survival of males subjects, but with ectodermal dysplasia and immunodeficiency. Male patients with skin, dental, and ocular abnormalities typical of those seen in female patients with IP (without immunodeficiency) are rare. We investigated four male patients with clinical hallmarks of IP. All four were found to carry the deletion normally associated with male lethality in utero. Survival in one patient is explained by a 47,XXY karyotype and skewed X inactivation. Three other patients possess a normal 46,XY karyotype. We demonstrate that these patients have both wild-type and deleted copies of the NEMO gene and are therefore mosaic for the common mutation. Therefore, the repeat-mediated rearrangement leading to the common deletion does not require meiotic division. Hypomorphic alleles, a 47,XXY karyotype, and somatic mosaicism therefore represent three mechanisms for survival of males carrying a NEMO mutation.     

The European carbon balance. Part 3: forests

We present a new synthesis, based on a suite of complementary approaches, of the primary production and carbon sink in forests of the 25 member states of the European Union (EU‐25) during 1990–2005. Upscaled terrestrial observations and model‐based approaches agree within 25% on the mean net primary production (NPP) of forests, i.e. 520±75 g C m^?2 yr^?1 over a forest area of 1.32 × 10⁶ km² to 1.55 × 10⁶ km² (EU‐25). New estimates of the mean long‐term carbon forest sink (net biome production, NBP) of EU‐25 forests amounts 75±20 g C m^?2 yr^?1. The ratio of NBP to NPP is 0.15±0.05. Estimates of the fate of the carbon inputs via NPP in wood harvests, forest fires, losses to lakes and rivers and heterotrophic respiration remain uncertain, which explains the considerable uncertainty of NBP. Inventory‐based assessments and assumptions suggest that 29±15% of the NBP (i.e., 22 g C m^?2 yr^?1) is sequestered in the forest soil, but large uncertainty remains concerning the drivers and future of the soil organic carbon. The remaining 71±15% of the NBP (i.e., 53 g C m^?2 yr^?1) is realized as woody biomass increments. In the EU‐25, the relatively large forest NBP is thought to be the result of a sustained difference between NPP, which increased during the past decades, and carbon losses primarily by harvest and heterotrophic respiration, which increased less over the same period.     

Nucleotide sequence of the genes for tryptophan synthase in Pseudomonas aeruginosa

We have determined the DNA sequence of the two adjacent genes for the alpha and beta chains of tryptophan synthase in Pseudomonas aeruginosa, along with 34 5'-flanking and 799 3'-flanking base pairs. The gene order is trpBA as predicted from earlier genetic studies, and the two cistrons overlap by 4 bp; a ribosome binding site for the second gene is evident in the coding sequence of the first gene. We have also determined the location of three large deletions eliminating portions of each gene. A detailed comparison of the deduced P. aeruginosa amino acid sequence with those published for E. coli, Bacillus subtilis, and Saccharomyces cerevisiae shows much similarity throughout the beta and most of the alpha subunit. Most of the residues implicated by chemical modification or mutation as being critical for enzymatic activity are conserved, along with many others, suggesting that three-dimensional structure has remained largely constant during evolution. We also report the construction of a recombinant plasmid that overproduces a slightly modified alpha subunit from P. aeruginosa that can form a functionally effective multimer with normal E. coli beta 2 subunit in vivo.      

Microorganisms as Possible Indicators of General Soil Pollution by Dioxin-Containing Defoliants

The diversity of microorganisms from soils treated in the past with various dosages of dioxin-containing defoliants was studied. Population alterations dependent on dioxin concentrations were elucidated. Soil fungi and, to a smaller extent, actinomycetes were found to be the most sensitive to dioxins.     

Antimicrobial Activities of Bacteriocins E 50–52 and B 602 Against Antibiotic-Resistant Strains Involved in Nosocomial Infections

The antimicrobial spectra of previously published bacteriocin E 50–52 (39 a.a.; 3,932 Da; pI = 8.5) and bacteriocin B 602 (29 a.a.; 3,864 Da; pI = 7.2) were determined. Named peptides were related to class IIa (pediocin-like) bacteriocins. Minimal inhibitory concentrations (MICs) of bacteriocins have been determined for bacterial isolates that were causative agents of nosocomial infections collected from Russian hospitals in 2003–2007, namely methicillin-resistant Staphylococcus aureus (MRSA) (n = 10); Acinetobacter baumannii (n = 11); Citrobacter freundii (n = 8); Escherichia coli (n = 9); Klebsiella pneumoniae (n = 10); Proteus spp. (n = 6); and Pseudomonas aeruginosa (n = 10). The majority of these tested isolates have been shown to be multidrug resistant and carry genetic determinants of antimicrobial resistance that were detected using polymerase chain reaction (PCR). The MICs of bacteriocin B 602 ranged from ≤0.025–1.56 μg/ml, and for bacteriocin E 50–52 from 0.05 to 6.25 μg/ml for all of 64 bacterial clinical isolates tested. Interestingly, the bacteriocins studied demonstrate activity on both Gram-positive and Gram-negative bacteria. Bacteriocins E 50–52 and B 602 show good activity against nosocomial bacterial agents resistant to many classes of modern antibacterials used in clinical practice. These bacteriocins should be examined as an alternative in treating infections caused by such agents.     

Structure and regulation of the anthranilate synthase genes in Pseudomonas aeruginosa: II. Cloning and expression in Escherichia coli

The genes for the large and small subunits of anthranilate synthase (trpE and trpG, respectively) have been cloned from Pseudomonas aeruginosa PAC174 into E. coli by R-prime formation with the broad-host- range plasmid R68.44. Sequential subcloning into plasmid vectors reduced the active Pseudomonas DNA fragment to a length of 3.1 kb. We obtained evidence that this region contains the promoter for its own expression and retains a vestigial regulatory response to tryptophan scarcity or excess.      

Genetic evidence of intercontinental movement of avian influenza in a migratory bird: the northern pintail (Anas acuta)

The role of migratory birds in the movement of the highly pathogenic (HP) avian influenza H5N1 remains a subject of debate. Testing hypotheses regarding intercontinental movement of low pathogenic avian influenza (LPAI) viruses will help evaluate the potential that wild birds could carry Asian-origin strains of HP avian influenza to North America during migration. Previous North American assessments of LPAI genetic variation have found few Asian reassortment events. Here, we present results from whole-genome analyses of LPAI isolates collected in Alaska from the northern pintail (Anas acuta), a species that migrates between North America and Asia. Phylogenetic analyses confirmed the genetic divergence between Asian and North American strains of LPAI, but also suggested inter-continental virus exchange and at a higher frequency than previously documented. In 38 isolates from Alaska, nearly half (44.7%) had at least one gene segment more closely related to Asian than to North American strains of LPAI. Additionally, sequences of several Asian LPAI isolates from GenBank clustered more closely with North American northern pintail isolates than with other Asian origin viruses. Our data support the role of wild birds in the intercontinental transfer of influenza viruses, and reveal a higher degree of transfer in Alaska than elsewhere in North America.     

Isolation of Lactobacillus salivarius 1077 (NRRL B-50053) and characterization of its bacteriocin, including the antimicrobial activity spectrum

Lactobacillus salivarius 1077 (NRRL B-50053) was isolated from poultry intestinal materials, and in vitro anti-Campylobacter jejuni activity was demonstrated. The isolate was then used for bacteriocin production and its enrichment. The protein content of the cell-free supernatant from the spent medium was precipitated by ammonium sulfate and dialyzed to produce the crude antimicrobial preparation. A typical bacteriocin-like response of sensitivity to proteolytic enzymes and resistance to lysozyme, lipase, and 100°C was observed with this preparation. The polypeptide was further purified by gel filtration, ion-exchange, and hydrophobic-interaction chromatography. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), Edman degradation, and isoelectrofocusing were used to characterize its 3,454-Da molecular mass, the amino acid sequence of its 37 residue components, and the isoelectric point of pI 9.1 of the bacteriocin. Bacteriocin L-1077 contained the class IIa bacteriocin signature N-terminal sequence YGNGV. MICs of bacteriocin L-1077 against 33 bacterial isolates (both Gram negative and Gram positive) ranged from 0.09 to 1.5 μg/ml. Subsequently, the therapeutic benefit of bacteriocin L-1077 was demonstrated in market-age (40- to 43-day-old) broiler chickens colonized with both C. jejuni and Salmonella enterica serovar Enteritidis. Compared with untreated control birds, both C. jejuni and S. Enteritidis counts in colonized ceca were diminished by >4 log(10) and S. Enteritidis counts in both the liver and the spleen of treated birds were reduced by 6 to 8 log(10)/g compared with those in the nontreated control birds. Bacteriocin L-1077 appears to hold promise in controlling C. jejuni/S. Enteritidis among commercial broiler chickens.