Effect of extrusion processing on the nutritional quality of protein in rice-legume blends

The effect of extrusion processing using Wenger X-5 extruder on the quality of products of rice-legume (75:25) blends was investigated. The products were palatable and had a good textur. The nutritional quality of protein in the extrudates was significantly improved. The protein efficiency ratio values of rice-soybean, rice-bengal gram and rice-black gram products were: 2.25, 2.30 and 2.28 as compared to 2.10, 1.89 and 1.98 for the respective raw blends. Extrusion processing reduced the phytates in the products to the extent of 20.3 to 26.8%.     

Mutations in Bartonella bacilliformis gyrB confer resistance to coumermycin A1

This study describes the first isolation and characterization of spontaneous mutants conferring natural resistance to an antibiotic for any Bartonella species. The Bartonella bacilliformis gyrB gene, which encodes the B subunit of DNA gyrase, was cloned and sequenced. The gyrB open reading frame (ORF) is 2,079 bp and encodes a deduced amino acid sequence of 692 residues, corresponding to a predicted protein of approximately 77.5 kDa. Sequence alignment indicates that B. bacilliformis GyrB is most similar to the GyrB protein from Bacillus subtilis (40.1% amino acid sequence identity) and that it contains the longest N-terminal tail (52 residues) of any GyrB characterized to date. The cloned B. bacilliformis gyrB was expressed in an Escherichia coli S30 cell extract and was able to functionally complement a temperature-sensitive E. coli Cour gyrB mutant (strain N4177). We isolated and characterized spontaneous mutants of B. bacilliformis resistant to coumermycin A1, an antibiotic that targets GyrB. Sequence analysis of gyrB from 12 Cour mutants of B. bacilliformis identified single nucleotide transitions at three separate loci in the ORF. The predicted amino acid substitutions resulting from these transitions are Gly to Ser at position 124 (Gly124-->Ser), Arg184-->Gln, and Thr214-->Ala or Thr214-->Ile, which are analogous to mutated residues found in previously characterized resistant gyrB genes from Borrelia burgdorferi, E. coli, Staphylococcus aureus, and Haloferax sp. The Cour mutants are three to five times more resistant to coumermycin A1 than the wild-type parental strain.     

The role of ATM in DNA damage responses and cancer

Ataxia-telangiectasia (AT) is a complex, autosomal recessive disorder characterized by cerebellar ataxia, believed to result from progressive neurodegeneration, and telangiectasia, dilation of blood vessels within the eyes and parts of the facial region. AT patients suffer from recurrent infections caused by both cellular and humoral immune deficiencies and as a population, are significantly predisposed to cancer, particularly lymphomas and leukemias. Early attempts at treating these malignancies with radiotherapy revealed another hallmark of AT, a profound hypersensitivity to the cytotoxic effects of ionizing radiation (IR) which is recapitulated at the cellular level in culture. Predisposition to cancer and radiosensitivity observed in AT has been linked to chromosomal instability, abnormalities in genetic recombination, and defective signaling to programmed cell death and several cell cycle checkpoints activated by DNA damage. These earlier observations predicted that the gene defective in AT may encode a protein which plays a crucial role in sensing DNA damage and transducing signals that promote cell survival. Through the combined efforts of linkage analysis and positional cloning, a single gene was identified on chromosome 11q22-33 by Shiloh and colleagues and was found to be mutated in all four complementation groups previously characterized in cell lines derived from AT patients (Savitsky et al., 1995a,b). The predicted ATM gene product shows considerable homology to an emerging family of high molecular weight, phosphatidylinositol-3 kinase (PI-3 K)-related proteins involved in eukaryotic cell cycle control, DNA repair, and DNA recombination (Zakian, 1995). This landmark discovery has triggered a resurgence of biochemical and genetic studies focusing on ATM function which has brought forth insights regarding ATM activity and its role in DNA damage signaling.     

A 66-year-old woman with pneumonia and right heart failure

PURPOSE: The purpose of this study was to develop a shaded-surface and volume display (hybrid rendering method) of the whole vascular system of the cervico-cranial arteries using spiral computed tomography (SCT). MATERIALS AND METHODS: We examined 12 patients with anatomic abnormalities and pathological conditions of the arterial vascular system. The cervico-cranial arteries were segmented using an interactive threshold interval density volume-growing method and visualized with a color-coded shaded-surface display (SSD) rendering method. The adjacent bone structures were visualized using a transparent volume rendering method. RESULTS: In all cases, the entire volume of the vascular system of the cervico-cranial arteries and the anatomic abnormalities and pathological conditions could be visualized. CONCLUSION: Hybrid rendering of the circulation of the cervico-cranial arteries using image data sets from a subsecond spiral CT scanner is useful for the visualization of anatomical and pathological abnormalities and offer a promising minimally invasive alternative compared with other diagnostic procedures.     

Mice lacking E-selectin show normal numbers of rolling leukocytes but reduced leukocyte stable arrest on cytokine-activated microvascular endothelium

OBJECTIVE: Previous work indicated that E-selectin mediates transient interactions between leukocytes and cytokine-activated endothelium in vitro. Here we examine the role of E-selectin in blood leukocyte interactions with microvascular endothelium in vivo. METHODS: E-selectin-deficient (E-/-) mice were produced by gene targeting. The effect of this null mutation on leukocyte-endothelial interactions was determined by intravital microscopy before and 4 to 5 hours after local administration of the proinflammatory cytokine tumor necrosis factor alpha (TNF alpha) in dermal microvessels with low blood flow (dorsal skin-fold chambers, intact ear skin), and after endotoxin activation in exteriorized mesenteric microvessels with higher blood flow. RESULTS: E-/- mice were viable, fertile with normal circulating leukocyte and platelet profiles. Approximately 60% of circulating leukocytes rolled in dermal microvessels of both normal (E+/+) and E-/- mice without inflammatory stimulation. After local administration of TNF alpha, rolling increased modestly and equivalently in both genotypes. The main effect of TNF alpha was a dramatic increase in leukocyte stable adhesion and, unlike rolling, this manifestation of endothelial activation was significantly reduced in E-/- animals. This reflected fewer dermal microvessels supporting higher adhesion densities in E-/- mice, and a similar trend was observed in mesenteric microvessels. CONCLUSIONS: E-selectin plays a previously unappreciated role in facilitating and/or mediating stable adhesion of leukocytes to inflamed microvascular endothelium.     

The importance of serum IgE for level and longitudinal change in airways hyperresponsiveness in COPD

BACKGROUND: Airways hyperresponsiveness (AHR) is an important feature of patients with chronic obstructive pulmonary disease (COPD). Little is known about factors that modulate AHR in COPD. OBJECTIVE: To study these factors, we performed a long-term, double-blind, parallel intervention study in 58 male, non-allergic patients with COPD. METHODS: During a period of 2 years, patients were treated with inhaled budesonide (1600 microg/day), inhaled budesonide (1600 microg/day) plus oral prednisolone (5 mg/day), or placebo. PC20 histamine was measured at 4-monthly intervals. The influence of treatment, smoking, age, level of lung function, initial serum IgE level and peripheral blood eosinophils on level and longitudinal change of PC20 histamine was analysed. RESULTS: During follow-up, PC20 decreased in our group, and this decrease was not influenced by treatment. PC20 tended to decrease faster in current smokers than in ex-smokers. PC20 was significantly associated with pre-challenge FEV1 at each time point. Level nor decline of PC20 were significantly related to age. A higher initial serum IgE level was independently associated with a lower PC20. Moreover, a higher initial serum IgE level was associated with a slower annual decline of PC20, regardless of treatment, pre-challenge FEV1, and other modulating factors. No significant associations were found between initial blood eosinophils and level or decline of PC20. CONCLUSION: We conclude that AHR increases over time in non-allergic patients with COPD. Treatment with an inhaled corticosteroid alone or in combination with oral prednisolone does not change this increase. Our study suggests an important role for IgE in the course of the disease, since a higher initial serum IgE level predicts a more favourable course with regard to annual decline of PC20 histamine.