Determination of benzoyl peroxide and benzoic acid levels by HPLC during wheat flour bleaching process

Freshly milled wheat flour has a pale yellow color due to its carotenoids content. Benzoyl peroxide is a bleaching agent typically used to give such flour a better appearance. This free-radical initiator promotes carotenoids oxidation, thereby producing less colored compounds, and benzoic acid is a main final product. Samples of wheat flour were treated with 150 ppm of benzoyl peroxide to begin a bleaching process, and then subjected to ethyl ether extraction at different intervals of time. Benzoyl peroxide and benzoic acid levels in these extracts were monitored by means of HPLC in individual experiences. The resulting concentration of benzoyl peroxide after 9 days of contact with the bleaching agent was 11 ppm, dropping afterward to nondetectable levels. A maximum value for benzoic acid of 16 ppm was found after 12 h of bleaching. Subsequently this level decreased continuously until reaching a residual value of 6 ppm after 3 months.

Local and systemic cytokine responses during experimental human influenza A virus infection. Relation to symptom formation and host defense

To further understand the role of cytokine responses in symptom formation and host defenses in influenza infection, we determined the levels of IL-1beta, IL-2, IL-6, IL-8, IFN-alpha, TGF-beta, and TNF-alpha in nasal lavage fluid, plasma, and serum obtained serially from 19 volunteers experimentally infected with influenza A/Texas/36/91 (H1N1) and correlated these levels with various measures of infection and illness severity. We found that IL-6 and IFN-alpha levels in nasal lavage fluids peaked early (day 2) and correlated directly with viral titers, temperature, mucus production, and symptom scores. IL-6 elevations were also found in the circulation at this time point. In contrast, TNF-alpha responses peaked later (day 3 in plasma, day 4 in nasal fluids), when viral shedding and symptoms were subsiding. Similarly, IL-8 peaked late in the illness course (days 4-6) and correlated only with lower respiratory symptoms, which also occurred late. None of IL-1beta, IL-2, or TGF-beta levels increased significantly. These data implicate IL-6 and IFN-alpha as key factors both in symptom formation and host defense in influenza.

Hematopoietic bone marrow in the adult knee: spin-echo and opposed-phase gradient-echo MR imaging

Hematopoietic bone marrow in the distal femur of the adult may be mistaken for a pathologic marrow process in magnetic resonance imaging of the knee. We investigated the incidence of hematopoietic marrow in the distal femur in a series of 51 adult patients and compared spin-echo (TR/TE in ms: 500/35, 2000/80) and opposed-phase gradient-echo (0.35 T, TR/TE in ms: 1000/30, theta = 75 degrees) magnetic resonance images. Zones with intermediate to low signal intensity on T1-weighted spin-echo and opposed-phase gradient-echo sequences representing hematopoietic marrow within high signal intensity fatty marrow were observed in 18 of the 51 patients. Five patterns of marrow signal reduction were identified; type 0: uniform high signal, i.e., no signal change; type I, focal signal loss; type II, multifocal signal loss without confluence; type III, confluent signal loss; and type IV, complete homogeneous reduction in marrow signal. Opposed-phase gradient-echo sequences demonstrated markedly greater red-yellow marrow contrast than conventional spin-echo sequences. Follow-up studies in three patients using a gradient-echo sequence with TE varying from 10 to 21 ms at 1-ms increments showed a cyclic increase and decrease in red and yellow marrow signal intensity depending on the TE. The contribution of intravoxel chemical shift effects on red-yellow marrow contrast in opposed-phase gradient-echo images was verified by almost complete cancellation of the TE-dependent marrow signal oscillation with use of a chemically selective pulse presaturating the water protons. Hematopoietic marrow in the adult distal femur in the absence of hematologic abnormalities is found primarily in women of menstruating age.(ABSTRACT TRUNCATED AT 250 WORDS)

[Residual and reconverted hematopoietic bone marrow in the distal femur. Spin-echo and opposed-phase gradient-echo MRT]

The distal femur contains usually only fatty marrow in the adult. We investigated the incidence of areas of residual and reconverted hematopoietic marrow in the distal femur in a series of 50 adult patients using conventional spin-echo and opposed-phase gradient-echo MR images. Zones with intermediate to low signal intensity in both sequences representing hematopoietic marrow within high signal intensity fatty marrow were observed in 17 of the 50 patients. Opposed-phase gradient-echo sequences demonstrated significantly greater red-yellow marrow contrast than conventional spin-echo sequences. Residual red marrow may represent a biologic variation of the normal adult pattern of red-yellow marrow distribution in women of menstruating age. Reconverted red marrow appears to be related to increased erythrocyte demand. It should not be mistaken for bone marrow malignancy. Absence of epiphyseal involvement, cortical destruction and soft-tissue mass in residual and reconverted hematopoietic marrow are helpful differential criteria.

Gastric H,K-ATPase topography: amino acids 888-907 are cytoplasmic

Gastric acidification is mediated by H,K-ATPase, an integral protein of apical membranes of gastric parietal cells. Hydropathy analysis of H,K-ATPase alpha subunit primary structure predicts eight transmembrane (TM) domains, while omeprazole-binding data were interpreted in terms of ten TM domains (Mercier et al. (1991) FASEB J. 5, A749). In the present study, tryptic hydrolysis of gastric mucosal microsomes gave a set of peptides which bound the monoclonal antibody HK 12.18, a highly specific probe of the H,K-ATPase. An antiserum against the C-terminus of H,K-ATPase alpha subunit bound the same peptides, and one smaller peptide. The binding data suggested a putative epitope for HK 12.18, and a 20-mer peptide encompassing this site was synthesized. This peptide bound directly to HK 12.18, displaced HK 12.18 from microsomal H,K-ATPase, and blocked HK 12.18 immunostaining of gastric parietal cells. In addition, intact gastric microsomes competitively inhibited binding of HK 12.18 to peptide-BSA conjugate. Taken together, these data place the HK 12.18 epitope between amino acids 888-907 and identify this domain as cytosolic. This result specifically excludes a pair of TM domains between the sixth and seventh TM alpha helices of the H,K-ATPase and supports a secondary structure model with eight TM domains.

Behaviour studies of the fungicide cymoxanil in two strains of the fungus Botrytis cinerea and in haemolymph of locust and lobster. I. In situ monitoring by internal surface reversed-phase high-performance liquid chromatography

A method for following the metabolism of the fungicide cymoxanil in various biological media is described. By using a recently developed high-performance liquid chromatographic method, with an internal surface reversed-phase column, it is unnecessary to clean up the sample before analysis. Thus this technique makes monitoring in fungi as well as in arthropod haemolymph easier and faster.

How to keep your best people for the '90s

Getting good people to join us merely sets the stage for achievement. the real payoff depends on how we deal with them and how long they stay. From the CEO's perspective, the most important requirements for the '90s are: Know what you mean by performance in all jobs, in all functions, and at all levels. Hire accountable people. Know what it takes to hire and keep the best people and do it. Invest what it takes to fill at least 70% of your promotions with people from the inside; they will consistently perform better than outsiders. Weed out non-performers promptly and as religiously as you seek outstanding new people. Have a human resource plan in place before you grow beyond your people's capability to deliver. Build a strong, active, useful board of directors to provide an objective perspective on your actions as CEO and on the development of the company. Do not try to clone yourself. Hire people who are better than you and keep them as long as you can. Listen to them; invest in them; and benefit from them, so that when you are ready for retirement, you can sit on their board of directors.

Distribution of rabbit mucosal glycoprotein throughout urinary tract

The mucin layer covering the transitional epithelium of the bladder is thought to be an anti-adherence substance for bacteria. We describe the use of an immunoperoxidase staining technique to demonstrate the presence of glycoprotein lining the urothelium of both the upper and lower urinary tracts of the rabbit. Antisera against this glycoprotein (GP1) were raised in Swiss-Webster mice. The genitourinary tracts of male and female NZW rabbits were removed and sequentially treated with mouse anti-GP1 sera, biotin-labelled anti-mouse IgG, and an avidin-biotinylated horseradish peroxidase complex. The results demonstrated that an antigenically similar (or identical) glycoprotein covers the distal renal tubules and urothelium of the renal pelvis, ureters, bladder, and urethra, suggesting that it may function as an antibacterial defense mechanism throughout the urinary tract.

Specificity of T lymphocyte lines for peptides of myelin basic protein

T lymphocyte lines specific for myelin basic protein (BP) can mediate experimental autoimmune encephalomyelitis (EAE), or can protect against the active induction of the disease. To investigate the antigenic fine specificity of guinea pig (GP) BP-specific T cell lines raised from different rat strains, and to determine whether functionally different T lymphocyte lines and clones recognized the same or different regions of the BP molecule, the proliferation responses of line cells were assessed after stimulation with purified peptides of GP-BP. Lewis rat T cell lines and clones selected for responses to whole GP-BP responded selectively to the 68-88 amino acid sequence of GP-BP, but not to the 1-37, 43-67, or 89-169 sequences. The region of GP-BP recognized by Lewis T cells was additionally defined to include the 75-80 amino acid sequence, because a T cell clone responded equally to GP and rat BP which differed by only one amino acid at position 79, but did not respond to human or bovine BP, which had a Gly-His insertion in this region. T lymphocyte lines derived from the F344 and PVG (Weizmann) rat strains shared the same selective response to peptide 68-88, but lines from BN rats responded to an epitope(s) outside of the 68-88 sequence. The functional capacity of the various T cell lines to mediate experimental autoimmune encephalomyelitis (EAE) or to induce resistance against EAE was independent of their specificity for the different GP-BP peptides; lines specific for epitope(s) within or excluded from the 68-88 sequence could be encephalitogenic depending on their strain of origin, and various lines specific for the 68-88 peptide could induce both disease and protection, disease only, or neither activity.

Specificity of T lymphocyte lines for peptides of myelin basic protein

T lymphocyte lines specific for myelin basic protein (BP) can mediate experimental autoimmune encephalomyelitis (EAE), or can protect against the active induction of the disease. To investigate the antigenic fine specificity of guinea pig (GP) BP-specific T cell lines raised from different rat strains, and to determine whether functionally different T lymphocyte lines and clones recognized the same or different regions of the BP molecule, the proliferation responses of line cells were assessed after stimulation with purified peptides of GP-BP. Lewis rat T cell lines and clones selected for responses to whole GP-BP responded selectively to the 68-88 amino acid sequence of GP-BP, but not to the 1-37, 43-67, or 89-169 sequences. The region of GP-BP recognized by Lewis T cells was additionally defined to include the 75-80 amino acid sequence, because a T cell clone responded equally to GP and rat BP which differed by only one amino acid at position 79, but did not respond to human or bovine BP, which had a Gly-His insertion in this region. T lymphocyte lines derived from the F344 and PVG (Weizmann) rat strains shared the same selective response to peptide 68-88, but lines from BN rats responded to an epitope(s) outside of the 68-88 sequence. The functional capacity of the various T cell lines to mediate experimental autoimmune encephalomyelitis (EAE) or to induce resistance against EAE was independent of their specificity for the different GP-BP peptides; lines specific for epitope(s) within or excluded from the 68-88 sequence could be encephalitogenic depending on their strain of origin, and various lines specific for the 68-88 peptide could induce both disease and protection, disease only, or neither activity.

Urinary bladder glycoproteins of the rabbit: extraction, biochemical and immunological studies

The mucin layer of the bladder covering the transitional epithelium is thought to be an anti-adherence substance for bacteria. We have previously demonstrated that removal of this layer results in increased bacterial colonization. In this present communication we report our attempts to isolate and characterize the components of the mucin layer. Bladders were removed from female NZW rabbits and the mucosal layer was extracted with 0.1 M NaCl. Fractional centrifugation and column chromatography on AcA 34 and AcA 22 resulted in the separation of a partially purified glycoprotein, containing 30% carbohydrate, migrating as a single peak (4.5S) in the analytical ultracentrifuge. It was immunogenic in mice and the antisera were used to develop both a radioimmunoassay and an enzyme linked immunosorbent assay (ELISA). The antigenic activity of the glycoprotein was destroyed by protease or extremes of pH, but not by several glycosidases. In addition the murine antisera could not be inhibited by a panel of naturally occurring glycoproteins or glycosaminoglycans.

A DNA recombinant database management system

A set of computer programs is described which constitutes a clone database management system. Maintenance of the database and the stocks of material is designed to be under the control of one person or group of people, who may insert, delete or modify data entries, and who may interrogate the database as to which stocks are in need of checking. The system is organised in such a way that information is freely and speedily available to all users. Database entries may be accessed by name or key word.

The effect of pre-existing bacteriuria on bladder resistance to superinfection in the rabbit

Pre-existing bacteriuria of 2 to 3 weeks' duration in the rabbit had no effect on either the histological integrity of the sialomucin layer (anti-adherence factor) of the bladder mucosa or the protective effect of this layer against super-infection.

Action de la septorine, phytotoxine synthétisée par Septoria nodorum, sur la phosphorylation oxydative dans les mitochondries isolées de Coléoptiles de Blé

Septorin is a phytotoxin produced by Septoria nodorum. It reduces the growth of susceptible wheat cultivar "Etoile de choisy" seedlings. On mitochondria isolated from the same cultivar, the septorin induces changes in respiratory activities similar to the 2,4 dinitrophenol (2,4 D) effects. In this paper, the conditions of "in vitro" production of septorin and the steps of the purification are described.