Human Zn-alpha 2-glycoprotein cDNA cloning and expression analysis in benign and malignant breast tissues

Two cDNA clones coding for Zn-alpha 2-glycoprotein (Zn-alpha 2-gp) have been isolated from a human breast library and their nucleotide sequences determined. The deduced amino acid sequence contains the coding information for a hydrophobic signal peptide and the 278 residues of the mature protein. Comparison of this sequence with that from the protein purified from plasma reveals four differences: two amino acid changes (Gln-67 and Glu-222) and insertion of two residues (Ile-75 and Phe-76). Northern-blot analysis showed that the Zn-alpha 2-gp gene is expressed in liver and normal breast, but not in placenta, ovary and thyroid. A comparative analysis in mammary tissues from women with different diseases revealed enhanced expression of Zn-alpha 2-gp gene in benign breast lesions and a variable expression level in breast cancers.     

Effects of environmental and spatial gradients on Quercus-dominated Mountain forest communities in the Hindu-Kush ranges of Pakistan

Quercus-dominated forests are among the most important broad-leaved evergreen forests of the Hindu Kush ranges and are currently prone to drastic anthropogenic and climatic changes. The aim of this study was to provide basic data for the development of a regional oak forest ecosystem framework for ecological restoration and management plan development to maintain local peoples’ livelihoods. Hence, we analyzed distribution patterns and environmental factors that affect regional oak forests’ species composition and diversity. Ward’s Agglomerative clustering divided oak-dominated forest communities into three groups: i.e., Group I, dominated by Quercus baloot had an importance value index (IVI) of 89.87 ± 4.31, Group II, dominated by Quercus dilatata had an IVI of 32.16 ± 15.01, and Group III, dominated by Quercus oblongata had an IVI of 83.14 ± 4.67, respectively. The environmental factors which vary significantly within these communities were latitude, elevation, clay content and bulk density of the soil. Wilting point, saturation point, and electrical conductivity were also considered as ecosystem structural variables. Canonical correspondence analysis (CCA) indicated that community structure was affected by various environmental factors including precipitation, slope angle, elevation, clay content, and relative humidity.     

Novel structurally designed vaccine for S. aureus α-hemolysin: protection against bacteremia and pneumonia

Staphylococcus aureus (S. aureus) is a human pathogen associated with skin and soft tissue infections (SSTI) and life threatening sepsis and pneumonia. Efforts to develop effective vaccines against S. aureus have been largely unsuccessful, in part due to the variety of virulence factors produced by this organism. S. aureus alpha-hemolysin (Hla) is a pore-forming toxin expressed by most S. aureus strains and reported to play a key role in the pathogenesis of SSTI and pneumonia. Here we report a novel recombinant subunit vaccine candidate for Hla, rationally designed based on the heptameric crystal structure. This vaccine candidate, denoted AT-62aa, was tested in pneumonia and bacteremia infection models using S. aureus strain Newman and the pandemic strain USA300 (LAC). Significant protection from lethal bacteremia/sepsis and pneumonia was observed upon vaccination with AT-62aa along with a Glucopyranosyl Lipid Adjuvant-Stable Emulsion (GLA-SE) that is currently in clinical trials. Passive transfer of rabbit immunoglobulin against AT-62aa (AT62-IgG) protected mice against intraperitoneal and intranasal challenge with USA300 and produced significant reduction in bacterial burden in blood, spleen, kidney, and lungs. Our Hla-based vaccine is the first to be reported to reduce bacterial dissemination and to provide protection in a sepsis model of S. aureus infection. AT62-IgG and sera from vaccinated mice effectively neutralized the toxin in vitro and AT62-IgG inhibited the formation of Hla heptamers, suggesting antibody-mediated neutralization as the primary mechanism of action. This remarkable efficacy makes this Hla-based vaccine a prime candidate for inclusion in future multivalent S. aureus vaccine. Furthermore, identification of protective epitopes within AT-62aa could lead to novel immunotherapy for S. aureus infection.     

Lysosomal–mitochondrial cross-talk during cell death

Lysosomes are membrane-bound organelles, which contain an arsenal of different hydrolases, enabling them to act as the terminal degradative compartment of the endocytotic, phagocytic and autophagic pathways. During the last decade, it was convincingly shown that destabilization of lysosomal membrane and release of lysosomal content into the cytosol can initiate the lysosomal apoptotic pathway, which is dependent on mitochondria destabilization. The cleavage of BID to t-BID and degradation of anti-apoptotic BCL-2 proteins by lysosomal cysteine cathepsins were identified as links to the mitochondrial cytochrome c release, which eventually leads to caspase activation. There have also been reports about the involvement of lysosome destabilization and lysosomal proteases in the extrinsic apoptotic pathway, although the molecular mechanism is still under debate. In the present article, we discuss the cross-talk between lysosomes and mitochondria during apoptosis and its consequences for the fate of the cell.     

Experiments on the use of ethylene dibromide as a fumigant for grain and seed

The toxicity of ethylene dibromide to Calandra oryzae and Tribolium species was determined in the absence and presence of grain. Its toxicity by oral administration was studied on rats and guinea-pigs. The quality of bread baked from flour fumigated with ethylene dibromide was found to be unimpaired. The germination capacity of wheat, barley, maize, peas and beans was not adversely affected by fumigation with ethylene dibromide. The results of large-scale fumigations are reported and the conditions discussed under which ethylene dibromide can be used advantageously as a fumigant for grain and seed stores on a commercial scale. A concentration of 50-75 g./m.² was found satisfactory.     

Maternal Antibody-Mediated Disease Enhancement in Type I Interferon-Deficient Mice Leads to Lethal Disease Associated with Liver Damage

Epidemiological studies have reported that most of the severe dengue cases occur upon a secondary heterologous infection. Furthermore, babies born to dengue immune mothers are at greater risk of developing severe disease upon primary infection with a heterologous or homologous dengue virus (DENV) serotype when maternal antibodies reach sub-neutralizing concentrations. These observations have been explained by the antibody mediated disease enhancement (ADE) phenomenon whereby heterologous antibodies or sub-neutralizing homologous antibodies bind to but fail to neutralize DENV particles, allowing Fc-receptor mediated entry of the virus-antibody complexes into host cells. This eventually results in enhanced viral replication and heightened inflammatory responses. In an attempt to replicate this ADE phenomenon in a mouse model, we previously reported that upon DENV2 infection 5-week old type I and II interferon (IFN) receptors-deficient mice (AG129) born to DENV1-immune mothers displayed enhancement of disease severity characterized by increased virus titers and extensive vascular leakage which eventually led to the animals’ death. However, as dengue occurs in immune competent individuals, we sought to reproduce this mouse model in a less immunocompromised background. Here, we report an ADE model that is mediated by maternal antibodies in type I IFN receptor-deficient A129 mice. We show that 5-week old A129 mice born to DENV1-immune mothers succumbed to a DENV2 infection within 4 days that was sub-lethal in mice born to naïve mothers. Clinical manifestations included extensive hepatocyte vacuolation, moderate vascular leakage, lymphopenia, and thrombocytopenia. Anti-TNFα therapy totally protected the mice and correlated with healthy hepatocytes. In contrast, blocking IL-6 did not impact the virus titers or disease outcome. This A129 mouse model of ADE may help dissecting the mechanisms involved in dengue pathogenesis and evaluate the efficacy of vaccine and therapeutic candidates.     

Batch and continuous transformation of progesterone by Rhizopus nigricans pellets in the presence of β-cyclodextrin

A pelleted morphological form of Rhizopus nigricans, which might be regarded as a naturally immobilized biomass, enabled development of a continuous process of progesterone 11α-hydroxylation in a laboratory-scale stirred tank bioreactor. β-Cyclodextrin was used to enhance steroid solubility in aqueous transformation media and consequently to increase the rate of steroid hydroxylation. Batch and continuous processes were performed with pellets of different average diameters, ranging from less than 1 mm to 7.5 mm. Mathematical model simulations of both operational modes confirmed the previously defined Michaelis–Menten kinetics for the biotransformation. A decrease in overall hydroxylation rate was noticed when pellets larger than 5 mm were used, which correlated with the lower area of outer surface of agglomerates where, presumably, most of the enzyme induction had taken place.     

A model of induced coupled movements in the human body: a case study

We present a case study of involuntary motion in one part of the body induced by a voluntary motion in another part. The case investigated was that of a steady-state motion of the fingers at various frequencies, which induced a similar kind of motion in the legs. These phenomena were observed in a subject practicing sphincter gymnastics, a physical therapy method in which repetitive motion of different muscles is exercised, and is known to induce motions in other muscles of the body. We show that a linear model, for which we give an experimental transfer function and demonstrate its validity, can describe the generation of the induced periodic motions by the voluntary motions. We compare the results of the transfer function with those of Von Holst's statistical analysis. Received: 21 August 1997 / Accepted in revised form: 26 January 1999