Effect of Soy Protein Subunit Composition on the Rheological Properties of Soymilk during Acidification

The effect of soy protein subunit composition on the acid-induced aggregation of soymilk was investigated by preparing soymilk from different soybean lines lacking specific glycinin and β-conglycinin subunits. Acid gelation was induced by glucono-δ-lactone (GDL) and analysis was done using diffusing wave spectroscopy and rheology. Aggregation occurred near pH 5.8 and the increase in radius corresponded to an increase in the elastic modulus measured by small deformation rheology. Diffusing wave spectroscopy was also employed to follow acid gelation, and data indicated that particle interactions start to occur at a higher pH than the pH of onset of gelation (corresponding to the start of the rapid increase in elastic modulus). The protein subunit composition significantly affected the development of structure during acidification. The onset of aggregation occurred at a higher pH for soymilk samples containing group IIb (the acidic subunit A₃) of glycinin, than for samples prepared from Harovinton (a commercial variety containing all subunits) or from genotypes null in glycinin. The gels made from lines containing group I (A₁, A₂) and group IIb (A₃) of glycinin resulted in stiffer acid gels compared to the lines containing only β-conglycinin. These results confirmed that the ratio of glycinin/β-conglycinin has a significant effect on gel structure, with an increase in glycinin causing an increase in gel stiffness. The type of glycinin subunits also affected the aggregation behavior of soymilk.     

The cysteine protease α-clostripain is not essential for the pathogenesis of Clostridium perfringens-mediated myonecrosis

Clostridium perfringens is the causative agent of clostridial myonecrosis or gas gangrene and produces many different extracellular toxins and enzymes, including the cysteine protease α-clostripain. Mutation of the α-clostripain structural gene, ccp, alters the turnover of secreted extracellular proteins in C. perfringens, but the role of α-clostripain in disease pathogenesis is not known. We insertionally inactivated the ccp gene C. perfringens strain 13 using TargeTron technology, constructing a strain that was no longer proteolytic on skim milk agar. Quantitative protease assays confirmed the absence of extracellular protease activity, which was restored by complementation with the wild-type ccp gene. The role of α-clostripain in virulence was assessed by analysing the isogenic wild-type, mutant and complemented strains in a mouse myonecrosis model. The results showed that although α-clostripain was the major extracellular protease, mutation of the ccp gene did not alter either the progression or the development of disease. These results do not rule out the possibility that this extracellular enzyme may still have a role in the early stages of the disease process.     

Distribution patterns of infection with multiple types of human papillomaviruses and their association with risk factors

Background

Infection with multiple types of human papillomavirus (HPV) is one of the main risk factors associated with the development of cervical lesions. In this study, cervical samples collected from 1,810 women with diverse sociocultural backgrounds, who attended to their cervical screening program in different geographical regions of Colombia, were examined for the presence of cervical lesions and HPV by Papanicolau testing and DNA PCR detection, respectively.

Principal Findings

The negative binomial distribution model used in this study showed differences between the observed and expected values within some risk factor categories analyzed. Particularly in the case of single infection and coinfection with more than 4 HPV types, observed frequencies were smaller than expected, while the number of women infected with 2 to 4 viral types were higher than expected. Data analysis according to a negative binomial regression showed an increase in the risk of acquiring more HPV types in women who were of indigenous ethnicity (+37.8%), while this risk decreased in women who had given birth more than 4 times (−31.1%), or were of mestizo (−24.6%) or black (−40.9%) ethnicity.

Conclusions

According to a theoretical probability distribution, the observed number of women having either a single infection or more than 4 viral types was smaller than expected, while for those infected with 2–4 HPV types it was larger than expected. Taking into account that this study showed a higher HPV coinfection rate in the indigenous ethnicity, the role of underlying factors should be assessed in detail in future studies.     

Tissue tropism and target cells of NSs-deleted rift valley fever virus in live immunodeficient mice

Background

Rift Valley fever virus (RVFV) causes disease in livestock and humans. It can be transmitted by mosquitoes, inhalation or physical contact with the body fluids of infected animals. Severe clinical cases are characterized by acute hepatitis with hemorrhage, meningoencephalitis and/or retinitis. The dynamics of RVFV infection and the cell types infected in vivo are poorly understood.

Methodology/Principal Findings

RVFV strains expressing humanized Renilla luciferase (hRLuc) or green fluorescent protein (GFP) were generated and inoculated to susceptible Ifnar1-deficient mice. We investigated the tissue tropism in these mice and the nature of the target cells in vivo using whole-organ imaging and flow cytometry. After intraperitoneal inoculation, hRLuc signal was observed primarily in the thymus, spleen and liver. Macrophages infiltrating various tissues, in particular the adipose tissue surrounding the pancreas also expressed the virus. The liver rapidly turned into the major luminescent organ and the mice succumbed to severe hepatitis. The brain remained weakly luminescent throughout infection. FACS analysis in RVFV-GFP-infected mice showed that the macrophages, dendritic cells and granulocytes were main target cells for RVFV. The crucial role of cells of the monocyte/macrophage/dendritic lineage during RVFV infection was confirmed by the slower viral dissemination, decrease in RVFV titers in blood, and prolonged survival of macrophage- and dendritic cell-depleted mice following treatment with clodronate liposomes. Upon dermal and nasal inoculations, the viral dissemination was primarily observed in the lymph node draining the injected ear and in the lungs respectively, with a significant increase in survival time.

Conclusions/Significance

These findings reveal the high levels of phagocytic cells harboring RVFV during viral infection in Ifnar1-deficient mice. They demonstrate that bioluminescent and fluorescent viruses can shed new light into the pathogenesis of RVFV infection.     

Physical activity and natural anti-VIP antibodies: potential role in breast and prostate cancer therapy

Background

There is convincing evidence from numerous clinical and epidemiological studies that physical activity can reduce the risk for breast and prostate cancer. The biological mechanisms underlying this phenomenon remain elusive. Herein we suggest a role for naturally produced antibodies reactive with the vasoactive intestinal peptide (VIP) in the suppression of breast and prostate cancer, which we believe could offer a possible molecular mechanism underlying control of these cancers by physical exercise.

Methodology and Results

We found that sera from individuals having breast and prostate cancers have decreased titers of VIP natural antibodies as demonstrated by a lower reactivity against peptide NTM1, having similar informational and structural properties as VIP. In contrast, sera collected from elite athletes, exhibited titers of natural NTM1-reactive antibodies that are significantly increased, suggesting that physical activity boosts production of these antibodies.

Significance

Presented results suggest that physical exercise stimulates production of natural anti-VIP antibodies and likely results in suppression of VIP. This, in turn, may play a protective role against breast and prostate cancers. Physical exercise should be further investigated as a potential tool in the treatment of these diseases.     

Cytological changes and alterations in polyamine contents induced by cadmium in tobacco BY-2 cells.

Changes in cell viability, proliferation, cell and nuclear morphology including nuclear and DNA fragmentation induced by 0.05 and 1 mM CdSO4 (Cd2+) in tobacco BY-2 cell line (Nicotiana tabacum L.) were studied in the course of 7 days. Simultaneously changes in endogenous contents of both free and conjugated forms of polyamines (PAs) were investigated for 3 days. The application of 0.05 mM Cd2+ evoked decline of cell viability to approximately 60% during the first 24 h of treatment. Later on degradation of cytoplasmic strands, formation of the stress granules and vesicles, modifications in size and shape of the nuclei, including their fragmentation, were observed in the surviving cells. Their proliferation was blocked and cells elongated. Beginning the first day of treatment TUNEL-positive nuclei were detected in cells cultivated in medium containing 0.05 mM Cd2+. Treatment with highly toxic 1 mM Cd2+ induced fast decrease of cell viability (no viable cells remained after 6-h treatment) and cell death occurred before DNA cleavage might be initiated. The exposure of tobacco BY-2 cells to 0.05 mM Cd2+ resulted in a marked accumulation of total PAs (represented by the sum of free PAs and their perchloric acid (PCA)-soluble and PCA-insoluble conjugates) during 3-day treatment. The increase in total PA contents was primarily caused by the increase in putrescine (Put) concentration. The accumulation of free spermidine (Spd) and spermine (Spm) at 12 and 24 h in 0.05 mM Cd2+ treated BY-2 cells and high contents of Spd and especially Spm determined in dead cells after I mM Cd2+ application was observed. The participation of PA conjugation with hydroxycinnamic acids and PA oxidative deamination in maintaining of free PA levels in BY-2 cells under Cd2+-induced oxidative stress is discussed.     

Synthesis of 9-alkyl and 9-heteroalkyl substituted 2-amino-6-guanidinopurines and their influence on the NO-production in macrophages

9-Alkyl and 9-heteroalkyl substituted derivatives of the 2-amino-6-guanidinopurine were synthesized by alkylation of 2-amino-6-chloropurine and subsequent guanidinolysis. The activity of the thus prepared compounds on murine macrophages was examined. Compounds 4a, 4b, and 4d inhibit the LPS+IFN-gamma-induced NO production in murine macrophages while compound 4h stimulates this production.