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.     

Primary mechanisms of the biological effect of electromagnetic fields

Based on the model of a bulk knitted structure, a possible mechanism of action of an external electromagnetic field on biological systems was proposed. The electromagnetic field affects biological processes through changes in the rates of biochemical reactions in response to changes in the conformational properties of water in the electromagnetic field.     

The dynamics of the subtalar joint in sudden inversion of the foot

The human subtalar joint was modelled as a quasi-linear second-order underdamped system to simulate sudden inversion motion of the foot relative to the shank. The model was fed with experimental data obtained from six subjects on a specially constructed apparatus. A total of 35 deg inversion was produced on the tested leg rapidly enough (lasting less than 40 ms) in order to ensure that the protective muscles are not activated. The parameters of the joint were evaluated and the following ranges were obtained at 35 deg inversion: elastic stiffness 14-52 Nm rad-1, damping coefficient 1.4-2.9 Nms rad-1, and natural frequency 78-125 Hz. The effects on the test parameters of weight bearing amount, foot dominance, and protective footwear were studied on one subject.     

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.      

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.     

Bi-lateral reactive force patterns in postural sway activity of normal subjects

Postural activity of normal subjects while standing still, as measured via the reactive foot-ground reactive forces, was investigated separately for each of the supporting legs, to provide detailed information on the individual activity of each side. Such information is not accessible if the overall reactive forces on the whole body are measured instead. Twenty-three normal adult subjects (average age 41 years) took part in the measuring tests, which were made on two collaterally installed force platforms. From the force traces obtained, the following parameters were determined: timings and amplitudes of the waveforms, separately for each foot and sequence of the force vectors on both feet and in relation to each other. Weight-bearing imbalance was defined in the vertical direction to express the difference between the average forces supported by each of the legs. Two parameters were defined by combining the force results obtained on each of the legs in the horizontal plane: sway total activity, representing the resultant of the added vectornorms in the anteroposterior and mediolateral directions, respectively; and asymmetry, representing the resultant of the subtracted above vector norms. The results indicated that, although the force traces were synchronous to each other, different vectorial force patterns were found, indicating different levels of stabilizing activities on each of the legs. This was also demonstrated by the fact that sway total activity was found considerably higher than the net reactive forces acting on the whole body during sway. Hence, in treating the external forces involved in the stabilization and regulation of human posture, the activity of each of the legs should be taken into account, rather than the resultant forces acting on the body as a whole. The obtained results may thus serve as input force vectors in a multi-segmental model of biped standing.This research was supported by the Technion V.P.R. Fund — M. Mandel Biomedical Engineering Research Fund