Multifaceted antibodies development against synthetic α-dystroglycan mucin glycopeptide as promising tools for dystroglycanopathies diagnostic

Glycoconjugate Journal - Dystroglycanopathies are diseases characterized by progressive muscular degeneration and impairment of patient’s quality of life. They are associated with altered...     

Giardia intestinalis escapes oxidative stress by colonizing the small intestine: A molecular hypothesis

Giardia intestinalis is the microaerophilic protozoon causing giardiasis, a common infectious intestinal disease. Giardia possesses an O(2) -scavenging activity likely essential for survival in the host. We report that Giardia trophozoites express the O(2) -detoxifying flavodiiron protein (FDP), detected by immunoblotting, and are able to reduce O(2) to H(2) O rapidly (～3 μM O(2) × min × 10(6) cells at 37 °C) and with high affinity (C(50) = 3.4 ± 0.7 μM O(2)). Following a short-term (minutes) exposure to H(2) O(2) ≥ 100 μM, the O(2) consumption by the parasites is irreversibly impaired, and the FDP undergoes a degradation, prevented by the proteasome-inhibitor MG132. Instead, H(2) O(2) does not cause degradation or inactivation of the isolated FDP. On the basis of the elevated susceptibility of Giardia to oxidative stress, we hypothesize that the parasite preferentially colonizes the small intestine since, compared with colon, it is characterized by a greater capacity for redox buffering and a lower propensity to oxidative stress.     

Stiefel-manifold learning by improved rigid-body theory applied to ICA

In previous contributions we presented a new class of algorithms for orthonormal learning of a linear neural network with p inputs and m outputs, based on the equations describing the dynamics of a massive rigid frame in a submanifold of R(p). While exhibiting interesting features, such as intrinsic numerical stability, strongly binding to the orthonormal submanifolds, and good controllability of the learning dynamics, tested on principal/independent component analysis, the proposed algorithms were not completely satisfactory from a computational-complexity point of view. The main drawback was the need to repeatedly evaluate a matrix exponential map. With the aim to lessen the computational efforts pertaining to these algorithms, we propose here an improvement based on the closed-form Rodriguez formula for the exponential map. Such formula is available in the p = 3 and m = 3 case, which is discussed with details here. In particular, experimental results on independent component analysis (ICA), carried out with both synthetic and real-world data, help confirming the computational gain due to the proposed improvement.     

Evidence that synthesis of the Saccharomyces cerevisiae mitochondrially encoded ribosomal protein Var1p may be membrane localized

The 5′-untranslated leaders of mitochondrial mRNAs appear to localize translation within the organelle. VAR1 is the only yeast mitochondrial gene encoding a major soluble protein. A chimeric mRNA bearing the VAR1 untranslated regions and the coding sequence for pre-Cox2p appears to be translated at the inner membrane surface. We propose that translation of the ribosomal protein Var1p is also likely to occur in close proximity to the inner membrane.     

Cell cycle-dependent changes in localization of a 210-kDa microtubule-interacting protein in Leishmania

Using the monoclonal antibody MA-01, a new 210-kDa microtubule-interacting protein was identified in Leishmania promastigotes by immunoblotting and by immunoprecipitation. The protein was thermostable and was located on microtubules prepared by taxol-driven polymerization in vitro. On fixed cells the antibody gave specific staining of flagellum, flagellar pocket, and mitotic spindle. Subpellicular microtubules were basically not decorated but posterior poles of the cells were labeled in a cell-cycle-dependent manner. In anterior and posterior poles of cells the 210-kDa protein codistributed with the 57-kDa protein, immunodetected with anti-vimentin antibody, that was located only on cell poles. Immunolocalization of the 57-kDa protein was most prominent in dividing cells. The presented data suggest that the 210-kDa protein is a newly identified microtubule-interacting protein of Leishmania that could be involved in anchoring the microtubules in posterior poles of these cells. The striking codistribution of the microtubule-interacting protein and the 57-kDa protein in protozoa is described for the first time.     

The modernizing Kazakhstan: a review of biomedical data

In order to focus the situation of Kazakhstan today in relation to the processes of modernization and transition to a market economy and to evidence their effects on the biology and health status of the population of Kazakhstan, we have reviewed recently available data for this region (1993-1999). Kazakhstan is still characterized by a pyramid shaped age distribution of its population and by a high incidence of not communicable diseases and lack of nutrient and micronutrients, especially among children. However, the population of Kazakhstan seems to be not immune to the diseases of the modernization. I.e., among women obesity is more frequent than underweight, especially in the urban areas. In rural populations the frequency of clinically relevant hypertension resulted low in the more isolated and traditionally living communities but it increased to 20% in the less isolated one. Although it is expected a strong increase of urbanized population in the next 25 years, currently, modernization is probably influencing life style and nutritional habits of almost only a minority of the inhabitants of Kazakhstan.     

Treatments with gras compounds to keep fig fruit (Ficus carica L.) quality during cold storage

The trade of fresh fig fruit is restricted by its high perishability and numerous attempts have been done to extend the postharvest life. The main difficulties can be found in the fast ripening and the easiness of pathogen spread. Although the ripening can be slowed by low storage temperatures (close to 0 degrees C) the control of pathogens remains still unsolved since no pesticide treatments are allowed. Generally Recognized As Save Compounds (G.R.A.S.) are possible candidates to fulfil this void. Sodium carbonate (SC) solutions (0.5, 1, 2 and 3%) and acetic acid (AAC) vapours (25, 50 and 100 ppm) have been used as postharvest treatments to control Botrytis cinerea on black (Craxiou de Porcu) and white (Rampelina) fig varieties. Fruit was subsequently stored at 2 or 8 degrees C and 90% relative humidity for two weeks. At the end of the experiment decay, weight loss, pH, acidity, total soluble solids and visual assessment were performed. SC treatment at 1% reduced significantly the decay while, lower and higher concentrations did not. Between the two studied varieties the lowest decay percentage (9.8%) was found for the Craxiou de Porcu. Using AAC a good efficacy was achieved only with 100 ppm, this treatment decrease to 2.4% the incidence of decay irrespective to storage temperature. Lower concentrations were lesser effective and the efficacy was strictly dependent on the storage temperature, being higher at 2 degrees C. No treatment damages were observed following SC or AAC applications. Regarding fruit weight loss all treatments did not affect this parameter that was 10.1% and 16.9% at 2 and 8 degrees C, respectively. Chemical analyses performed at the end of the storage period did not evidenced differences among the treatments and slight ones if compared to initial values. Visual score of the fruit at the end of storage evidenced a better keeping quality for Craxiou de Porcu especially when stored at 2 degrees C. Both G.R.A.S. compounds are promising, but in the reported experiments AAC was the most effective.     

4-hydroxy-2,3 trans-nonenal nuclear concentration inversely correlates with the growth rate of T leukemia cells

4-hydroxy-2,3 trans-nonenal is the major diffusible product generated by linoleic and arachidonic acids peroxidation. Its endogenous content is inversely related to the rate of cell proliferation and directly related to the level of cell differentiation. As previously reported, the nuclear localization of the aldehyde has been observed by means of a fluorescent antibody and confocal microscopy, and its concentration measured by electrospray/mass spectrometry, a sensitive and selective method for 4-hydroxy-2,3 trans-nonenal determination, on nuclear extracts of leukemic cells. With the aim to establish a possible correlation between the peroxidation product nuclear concentration and cell growth rate, Jurkat 6 leukemic cells have been used and the aldehyde measured by electrospray/mass spectrometry. The cells arrested in G1 show a content of 4-hydroxy-2,3 trans-nonenal significantly increased with respect to control ones.     

Gene expression phenotype in heterozygous carriers of ataxia telangiectasia

The defining characteristic of recessive diseases is the absence of a phenotype in the heterozygous carriers. Nonetheless, subtle manifestations may be detectable by new methods, such as expression profiling. Ataxia telangiectasia (AT) is a typical recessive disease, and individual carriers cannot be reliably identified. As a group, however, carriers of an AT disease allele have been reported to have a phenotype that distinguishes them from normal control individuals: increased radiosensitivity and risk of cancer. We show here that the phenotype is also detectable, in lymphoblastoid cells from AT carriers, as changes in expression level of many genes. The differences are manifested both in baseline expression levels and in response to ionizing radiation. Our findings show that carriers of a recessive disease may have an "expression phenotype." In the particular case of AT, this suggests a new approach to the identification of carriers and enhances understanding of their increased cancer risk. More generally, we demonstrate that genomic technologies offer the opportunity to identify and study unaffected carriers, who are hundreds of times more common than affected patients.