Beta-thalassemia in Iran: a high incidence of the nonsense codon 39 mutation on the island of Queshm

Optic disc blood flow velocity was measured in healthy patients, those with primary open angle glaucoma (POAG), and patients with normal pressure glaucoma (NPG). The velocity of the red blood cells (RBCs) in the capillaries of the optic nerve head (ONH) has been measured with a laser Doppler velocimeter (LDV), and blood viscosity has been evaluated notably by determining the aggregability of the RBCs with an erythroaggregameter. Our results in POAG patients and NPG patients showed that their optic nerve blood flow velocity was reduced and that the aggregability of the RBCs was increased. The hyperaggregability of the erythrocytes is responsible for the increase of the local viscosity in the papillary capillary network. These haemodynamic modifications observed in patients with glaucoma support the hypothesis of a vasogenic mechanism that could impair the optic nerve in glaucoma patients.     

Mapping of specific and promiscuous HLA-DR-restricted T-cell epitopes on the Plasmodium falciparum 27-kilodalton sexual stage-specific antigen

We have characterized HLA-DR-restricted T-cell epitopes on the 27-kDa protein (Pfg27), a sexual stage-specific antigen, of the human malaria parasite Plasmodium falciparum in subjects with a history of malaria. Pfg27, expressed early in the sexual stages, is recognized by monoclonal antibodies capable of reducing the infectivity of gametocytes in mosquitoes. By using 16 Pfg27-specific CD4(+)-T-cell clones derived from three donors, seven different T-cell epitopes were identified. Among them, P11 (amino acids 191 to 210 of the Pfg27 sequence, IDVVDSYIIKPIPALPVTPD) was found to contain a previously described binding motif for multiple HLA-DR allotypes. Indeed, P11 was found to be promiscuous in that it could be recognized by T cells in the context of at least five different HLA-DR molecules. The cytokine profile of the clones was mixed. Seven of nine T-cell clones exhibited a Th0-like cytokine profile, producing high levels of gamma interferon (IFN-gamma) and interleukin-4 (IL-4) upon stimulation with specific peptides and mitogens. The other two clones had a Th1-like cytokine profile with high expression of IFN-gamma and no IL-4. Identification of a promiscuous epitope in Pfg27 could play a significant role in the design of a subunit vaccine for suppressing malaria transmission.     

Translation eukaryotic initiation factor 4G recognizes a specific structural element within the internal ribosome entry site of encephalomyocarditis virus RNA

A complex of eukaryotic initiation factors (eIFs) 4A, 4E, and 4G (collectively termed eIF4F) plays a key role in recruiting mRNAs to ribosomes during translation initiation. The site of ribosomal entry onto most mRNAs is determined by interaction of the 5'-terminal cap with eIF4E; eIFs 4A and 4G may facilitate ribosomal entry by modifying mRNA structure near the cap and by interacting with ribosome-associated factors. eIF4G recruits uncapped encephalomyocarditis virus (EMCV) mRNA to ribosomes without the involvement of eIF4E by binding directly to the approximately 450-nucleotide long EMCV internal ribosome entry site (IRES). We have used chemical and enzymatic probing to map the eIF4G binding site to a structural element within the J-K domain of the EMCV IRES that consists of an oligo(A) loop at the junction of three helices. The oligo(A) loop itself is not sufficient to form stable complexes with eIF4G since alteration of its structural context abolished its interaction with eIF4G. Addition of wild type or trans-dominant mutant forms of eIF4A to binary IRES.eIF4G complexes did not further alter the pattern of chemical/enzymatic modification of the IRES.     

Weldability and high temperature performance of welded joints of heat-resisting alloys

The applications of various heat resisting alloys applications depend upon the service temperature and the environment in which they are employed; austenitic stainless steels are employed mainly in the temperature region of approximately 850-950 K and Fe-base, Co-base and Ni-base superalloys are employed for high-temperature use at more than approximately 950 K. Problems concerning the integrity of weld procedures and high-temperature performance of weld zones should be considered for the application of these heat-resisting alloys to welded structures. In fact, most heat resisting alloys have poor weldability compared with carbon and low-alloy steels and are subject to problems such as cracking during welding. Furthermore, there are many instances of deteriorating high-temperature performance of the weld zone due to changes in the microstructure which accompany welding. On the other hand, heat-resisting alloys are employed in severe high-temperature environments and it is highly possible that there will be an occurrence of fissures and deterioration due to deformation, creep damage, oxidation and carburising. There are many cases where materials which have been in service for extended periods have increased weld crack susceptibility. Repair welding of these requires further attention to be given to the possibility of weld cracks.     

A Multipitch Analyzer Based on Harmonic Temporal Structured Clustering

This paper proposes a multipitch analyzer called the harmonic temporal structured clustering (HTC) method, that jointly estimates pitch, intensity, onset, duration, etc., of each underlying source in a multipitch audio signal. HTC decomposes the energy patterns diffused in time-frequency space, i.e., the power spectrum time series, into distinct clusters such that each has originated from a single source. The problem is equivalent to approximating the observed power spectrum time series by superimposed HTC source models, whose parameters are associated with the acoustic features that we wish to extract. The update equations of the HTC are explicitly derived by formulating the HTC source model with a Gaussian kernel representation. We verified through experiments the potential of the HTC method