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Sample records for rapid latex agglutination

  1. A rapid latex agglutination test for detection of leptospiral antibodies.

    PubMed

    Ramadass, P; Samuel, B; Nachimuthu, K

    1999-10-01

    A rapid semi-quantitative latex agglutination test (LAT) has been standardized for the detection of leptospiral antibodies in serum samples of man and animals. The efficacy of the LAT was compared with the plate enzyme linked immunosorbent assay (ELISA). A total of 276 human serum samples were analyzed by both LAT and ELISA and percentage positives were 84.8 and 85.9%, respectively. Similarly, of 65 animal samples tested, 63.1 and 69.2% positivity were observed in LAT and ELISA, respectively. Even though the ELISA test was slightly more sensitive than LAT, the rapidity, simplicity and economics of the LAT were found to fulfill the requirements of a screening test for leptospiral antibodies.

  2. Commercial latex agglutination test for rapid diagnosis of group B streptococcal infection in infants.

    PubMed Central

    Webb, B J; Baker, C J

    1980-01-01

    Although latex agglutination assays for detection of a variety of bacterial antigens in body fluids from patients with systemic infection have been shown to be useful as rapid diagnostic techniques, lack of commercial availability has restricted their application. The Streptex latex test kit for the detection of group B streptococcal (GBS) antigen in admission body fluid specimens was evaluated for sensitivity and specificity in 54 infants with meningitis and in 10 infants with normal cerebrospinal fluid (CSF) parameters. GBS antigen was detected in 22 of 28 (78.6%) CSF specimens by latex agglutination and in 23 of 28 (82.1%) by countercurrent immunoelectrophoresis. Antigen was present in 21 of 28 (latex agglutination) and 19 of 26 (countercurrent immunoelectrophoresis) CSF specimens after the initiation of antimicrobial therapy. Heat-labile factors accounted for nonspecific agglutination reactions with latex suspensions other than group B in 3 of 28 CSF samples from patients with GBS meningitis. These nonspecific reactions were readily eliminated by heating specimens for 10 min at 100 degrees C. Fifteen patients with GBS meningitis had admission serum and urine samples collected in addition to CSF. Antigen was detected by latex agglutination and countercurrent immunoelelectrophoresis in 14 of 15 (93.3%) and 13 of 15 (86.7%) concentrated urine specimens, respectively, and in 12 of 15 (80%) CSF specimens and 4 of 15 (27%) sera by each method. These findings indicate that the Streptex latex test is a rapid, sensitive, and readily available method for detection of GBS antigen in admission body fluid specimens from infants with meningitis. PMID:7012177

  3. Evaluation of a commercial latex agglutination test for rapid detection of Salmonella in fecal samples.

    PubMed

    Bänffer, J R; van Zwol-Saarloos, J A; Broere, L J

    1993-08-01

    A latex agglutination test for the detection of salmonella in feces was evaluated in comparison to direct culture and enriched culture using both artificially inoculated samples and clinical samples. In the samples inoculated artificially with different concentrations of salmonella (10(1) to 10(5) per gram) the enriched culture performed better only at the 10(2) level in 0.4 g samples, whereas the latex test performed as well as the enriched culture at all levels in 4 g samples. In the tests using clinical samples, there was no significant difference between results of the latex test performed in 2283 samples and the enriched culture performed in 2072 samples. The sensitivity, specificity and negative and positive predictive values of the latex test were 88.2%, 98%, 97.5% and 63% respectively. The test provided results rapidly but yielded a number of false positive results.

  4. Rapid latex particle agglutination test for Escherichia coli strains of porcine origin producing heat-labile enterotoxin.

    PubMed Central

    Finkelstein, R A; Yang, Z S; Moseley, S L; Moon, H W

    1983-01-01

    A latex particle agglutination test previously shown to be suitable for the rapid identification of Escherichia coli strains of human origin producing heat-labile enterotoxin (R. A. Finkelstein and Z. Yang, J. Clin. Microbiol. 18:23-28) is equally applicable to strains of porcine origin. PMID:6361056

  5. Evaluation of the MycoAKT latex agglutination test for rapid diagnosis of Mycobacterium avium complex infections.

    PubMed

    Olano, J P; Holmes, H; Woods, G L

    1998-01-01

    Rapid diagnosis of Mycobacterium avium complex (MAC) bacteremia is important for management of patients with the acquired immunodeficiency syndrome who have disseminated MAC. The purpose of this study was to determine the reliability of the MycoAKT latex agglutination test for direct detection of MAC in positive mycobacterial blood cultures. First, colonies of isolates of previously identified mycobacteria, including 35 MAC, were tested. Of the 55 isolates evaluated, 33 were identified as MAC by the latex test, including 31 of the known MAC and 2 M. chelonae (sensitivity, 88.6%; specificity, 90.0%). Second, broth from 20 ESP II and 20 BACTEC 12B bottles seeded with isolates of MAC were tested. Aliquots from 19 (95%) ESP II cultures and 16 (80%) 12B cultures were positive by the latex test. In phase 3, broth from 115 signal-positive ESP II blood cultures were tested by latex agglutination. Forty-three subcultures from these bottles grew mycobacteria (41 MAC and 2 Mycobacterium tuberculosis complex); the remainder grew no organisms. Broth from 40 of the blood cultures (39 that grew MAC and 1 from which no organisms were recovered) were latex positive; thus, the sensitivity, specificity, and positive and negative predictive values of the latex test for direct identification of MAC in ESP II blood cultures were 95.1, 98.6, 97.5, and 97.3%, respectively. The mean time to detection of MAC was 14.6 days (range, 6-34 days) with the direct latex test, compared with 18.3 days (range, 9-36 days) with subculture and probe (p < 0.05).

  6. The latex agglutination test versus counterimmunoelectrophoresis for rapid diagnosis of bacterial meningitis

    PubMed Central

    Bortolussi, Robert; Wort, Arthur J.; Casey, Stephanie

    1982-01-01

    A modified latex agglutination (LA) test was compared with Gram-staining and counterimmunoelectrophoresis (CIE) for the rapid detection in the cerebrospinal fluid (CSF) of antigen to Haemophilus influenzae type b, Neisseria meningitidis groups A, B and C, Escherichia coli K1, Streptococcus pneumoniae and group B streptococci, seven frequent causes of bacterial meningitis in children. Of 50 CSF samples from patients with culture-proven bacterial meningitis 90% were correctly shown by the LA test to contain antigen of the responsible organism. Gram-staining revealed organisms in 80% of 45 of these samples. In 75% of the 40 samples that were of sufficient volume for CIE, positive results for the appropriate antigen were obtained. The concentration of antigen detected in the CSF by the LA test varied from undetectable to 800 000 ng/ml. Patients with a high concentration (more than 2000 ng/ml or a positive result at dilutions of CSF over 1/8) were significantly more likely to have a poor response to therapy (two died and two had persistent pleocytosis or bacteria in the CSF) than patients with a lower concentration (4/16 v. 0/18, P < 0.05). After appropriate therapy was begun the concentration of antigen fell dramatically, but measurable amounts of antigen persisted in the CSF for up to 6 days. The LA test detected bacterial antigen at concentrations 2 to 70 times below the lower limit detected by CIE. In seven additional patients who had received antibiotics before lumbar puncture was performed the LA test detected antigen from meningitis-causing bacteria even though cultures of the CSF were sterile. In another 145 patients who did not have meningitis the results of the LA test were negative. The LA test, done as described in this article, is easier to perform than CIE and should be a useful addition to the diagnostic tests carried out on the CSF of any patient suspected of having meningitis. PMID:6749272

  7. Rapid detection of human group C rotaviruses by reverse passive hemagglutination and latex agglutination tests using monoclonal antibodies.

    PubMed Central

    Kuzuya, M; Fujii, R; Hamano, M; Nagabayashi, T; Tsunemitsu, H; Yamada, M; Nii, S; Mori, T

    1993-01-01

    Reverse passive hemagglutination (RPHA) tests and a latex agglutination test with monoclonal antibodies (MAbs) were developed for the rapid detection of noncultivatable human group C rotaviruses. For RPHA tests, two MAbs, MAb 5A12 recognizing the outer capsid and MAb 13A3 recognizing the inner capsid, were separately used for the coating of sheep erythrocytes (SRBCs). Forty-six fecal samples were examined to confirm the practicality of the tests. As a result, there was concordance between the RPHA test with SRBCs coated with MAb 5A12 and polyacrylamide gel electrophoresis of viral RNA (RNA-PAGE) in 44 (95.6%) of 46 samples, while the diagnoses by the RPHA test with SRBCs coated with MAb 13A3 were in complete agreement with those by RNA-PAGE. Furthermore, a latex agglutination test with MAb 13A3 was also developed, and this test was fast enough and sensitive enough to successfully detect the viruses from most fecal samples within 2 min. The present procedures would be useful for the diagnosis of human group C rotavirus infections in clinical laboratories which are not well equipped. Images PMID:8388891

  8. Detection of staphylococcal exfoliative toxin by slide latex agglutination.

    PubMed Central

    Murono, K; Fujita, K; Yoshioka, H

    1988-01-01

    A simple and rapid method in which slide latex agglutination was used was developed to detect the exfoliative toxin (ET) elaborated by clinical isolates. ET types A and B (ET-A and ET-B) were purified by plate gel isoelectrofocusing, and anti-ET sera were obtained by immunizing rabbits. A specific immunoglobulin G antitoxin was then prepared from the immunized rabbit sera by fast protein liquid chromatography, and latex particles were coated with the antitoxin. Of 74 staphylococcal strains isolated from patients with staphylococcal scalded skin syndrome, 61 strains were found to produce ET by the newborn mouse bioassay. All 61 strains were shown to be positive for ET-A and ET-B production by the slide latex agglutination method. The lowest concentration of ETs detected by the latex agglutination method was 0.5 microgram/ml, which was much lower than that detected by the double immunodiffusion method, with a sensitivity of 50 micrograms/ml. It is crucial to prove ET production by clinical isolates for the diagnosis and surveillance of staphylococcal scalded skin syndrome. The latex agglutination method is a sensitive, simple, and rapid test which can be used as an alternative to the newborn mouse bioassay. Images PMID:3343322

  9. Rapid detection of infectious mononucleosis-associated heterophile antibodies by a novel immunochromatographic assay and a latex agglutination test.

    PubMed Central

    Farhat, S E; Finn, S; Chua, R; Smith, B; Simor, A E; George, P; Diena, B B; Diena, D; Skulnick, M

    1993-01-01

    A novel immunochromatographic assay, the CARDS O.S. MONO test (Pacific Biotech, San Diego, Calif.), and a latex agglutination test, the Infectious Mononucleosis Kit (Unipath Ltd., Hampshire, United Kingdom) were compared with the Paul-Bunnell-Davidsohn test. Of the 957 serum specimens studied, 78 were positive and 879 were negative by the Paul-Bunnell-Davidsohn test. After discrepancies were resolved by determining Epstein-Barr virus serology, the sensitivities of the CARDS O.S. MONO test and the Infectious Mononucleosis Kit were 91.0 and 96.2%, respectively, and both tests had a specificity and a positive predictive value of 100% and a negative predictive value and overall agreement of greater than 99%. The results show that both tests can accurately detect infectious mononucleosis-associated heterophile antibodies. PMID:8315001

  10. Latex agglutination test (LAT) for the diagnosis of typhoid fever.

    PubMed

    Sahni, Gopal Shankar

    2013-06-01

    The efficacy of latex agglutination test in the rapid diagnosis of typhoid fever was studied and the result compared with that of blood culture. This study included 80 children suffering from typhoid fever, among which 40 were confirmed by blood culture isolation and 40 had possible typhoid fever based on high Widal's titre (a four-fold rise in the titre of antibody to typhi "O" and "H" antigen was considered as a positive Widal's test result). Eighty children, 40 with febrile illness confirmed to be other than typhoid and 40 normal healthy children were used as negative controls. The various groups were: (i) Study group ie, group I had 40 children confirmed by culture isolation of Salmonella typhi(confirmed typhoid cases). (ii) Control groups ie, (a) group II with 40 febrile controls selected from paediatrics ward where cause other than S typhi has been established, (b) group III with 40 afebrile healthy controls that were siblings of the children admitted in paediatric ward for any reason with no history of fever and TAB vaccination in the last one year, and (c) group IV with 40 children with high Widal's titre in paired sera sample. Widal's test with paired sera with a one week interval between collections were done in all 40 patients. Latex aggtutination test which could detect 900 ng/ml of antigen as observed in checker board titration, was positive in all 40 children from group I who had positive blood culture and in 30 children from group IV who had culture negative and had high Widal's titre positive. Latex agglutination test was positive in 4 children in group II and none in group III. Using blood culture positive cases as true positive and children in groups II and III as true negative, the test had a sensitivity of 100% and specificity of 96%. Latex agglutination test was found to be significantly sensitive (100%) and specific (96%) and could detect 75% more cases in group IV (possible typhoid cases). Thus latex agglutination test can be used for rapid

  11. Comparison of latex agglutination, wet preparation, and culture for the detection of Trichomonas vaginalis

    PubMed Central

    Adu-Sarkodie, Y; Opoku, B; Danso, K; Weiss, H; Mabey, D

    2004-01-01

    Objectives: To compare the performance of three diagnostic methods for Trichomonas vaginalis infection—latex agglutination, saline wet mount, and culture. Methods: Vaginal swabs from 3807 women attending antenatal clinics were tested for the presence of T vaginalis by latex agglutination. All positives and the following two negatives were tested by wet preparation and culture. Results: The prevalence of infection by latex agglutination was 5.4%. Using an expanded gold standard based on the wet mount and culture results, the sensitivity of the latex agglutination test was 98.8% (95% CI 95.9 to 99.9) and specificity was 92.1 (89.2 to 94.5). The kappa index for test agreement was 0.93 for latex and culture and 0.88 for latex and wet preparation. Conclusion: The latex agglutination test is a highly sensitive test for detecting T vaginalis infection. It is a simple rapid test and has the potential for use in screening and diagnostic settings. PMID:15170003

  12. Rapid Detection of Contagious Caprine Pleuropneumonia Using a Mycoplasma capricolum subsp. capripneumoniae Capsular Polysaccharide-Specific Antigen Detection Latex Agglutination Test

    PubMed Central

    March, J. B.; Gammack, C.; Nicholas, R.

    2000-01-01

    Latex microspheres (diameter, 8 μm) were coated with anti-Mycoplasma capricolum subsp. capripneumoniae polyclonal immunoglobulin G (IgG) antiserum (anti-F38 biotype). The coated microspheres, when used in a latex agglutination test (LAT), detected M. capricolum subsp. capripneumoniae antigen in the serum of goats with contagious caprine pleuropneumoniae (CCPP). Beads also agglutinated strongly in the presence of purified M. capricolum subsp. capripneumoniae capsular polysaccharide (CPS). Preabsorption of CPS-specific antibodies prior to coating of the beads removed agglutinating activity in the presence of M. capricolum subsp. capripneumoniae, strongly suggesting that CPS is the likely soluble antigen recognized by the test. In addition, the specificity of the LAT exactly mirrored that of an M. capricolum subsp. capripneumoniae CPS-specific monoclonal antibody (WM25): of the 8 other mycoplasma species tested, agglutination was observed only with bovine serogroup 7. The LAT detected all 11 strains of M. capricolum subsp. capripneumoniae examined in this study, with a sensitivity level of 2 ng of CPS, or the equivalent of 1.7 × 104 CFU, in a reaction volume of 0.03 ml of serum. With field sera from goats with CCPP, the results of the LAT exhibited a 67% correlation with the results of the currently used complement fixation test (CFT), with the main discrepancy in diagnosis resulting from the increased sensitivity of the LAT compared to that of CFT. This antigen-detection LAT should prove particularly useful in identifying animals in the earliest stages of CCPP and combines sensitivity and low cost with ease of application in the field, without the need for any specialist training or equipment. PMID:11060083

  13. Human African trypanosomiasis: a latex agglutination field test for quantifying IgM in cerebrospinal fluid.

    PubMed Central

    Lejon, V.; Büscher, P.; Sema, N. H.; Magnus, E.; Van Meirvenne, N.

    1998-01-01

    LATEX/IgM, a rapid agglutination test for the semi-quantitative detection of IgM in cerebrospinal fluid of patients with African trypanosomiasis, is described in this article. The lyophilized reagent has been designed for field use and remains stable at 45 degrees C for one year. The test has been evaluated on cerebrospinal fluid samples from trypanosome-infected and non-infected patients, by comparison with commercial latex agglutination, radial immunodiffusion, and nephelometry. All test systems yielded similar results. PMID:10191550

  14. Latex agglutination using the periplasmic proteins antigen of Brucella melitensis is a successful, rapid, and specific serodiagnostic test for ovine brucellosis.

    PubMed

    Ismael, Alaa Bassuny; Swelum, Ayman Abdel-Aziz; Mostafa, Salama A-H; Alhumiany, Abdel-Rahman A

    2016-09-01

    Brucellosis, especially caused by Brucella melitensis, is considered the most-widespread zoonosis in the world, particularly in developing countries. This study was planned to develop an accurate test for diagnosis of ovine brucellosis using a specific hot saline extracted soluble Brucella melitensis periplasmic proteins (SBPPs). The efficacy of the latex agglutination test (LAT) using SBPPs compared to the Rose Bengal test (RBT), buffered plate agglutination test (BPAT), serum agglutination test (SAT), and an indirect enzyme-linked immunosorbent assay (i-ELISA) was evaluated in the field diagnosis of ovine brucellosis. The test performance was evaluated by estimating sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), disease prevalence (DP), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) using test agreement and bacteriological culture in 1777 samples. The false-positive result was significantly (P ⩽0.05) lower in LAT than RBT, BPAT, SAT, and i-ELISA. With reference to test agreement, the Se, Sp, PPV, and PLR were highest (P ⩽0.05) in LAT 99.33%, 99.88%, 98.68%, and 827.25%, respectively. With reference to bacteriological culture, the LAT and i-ELISA tests showed a significant difference in Se with SAT. However, no significant difference in specificity was detected. The DP was 8.44% in the five tests. In conclusion, LAT using SBPPs of B. melitensis could be a suitable serodiagnostic field test for ovine brucellosis, with high sensitivity and specificity.

  15. [Comparative measurement of antithrombin III by latex agglutination and radial immunodiffusion in patients with peritonitis].

    PubMed

    Miagkova, M A; Aleshkin, A V; Abramenko, T V; Savitskaia, Iu A; Aleshkin, V A

    1997-01-01

    A highly sensitive and rapid method, based on latex agglutination, has been developed for measuring antithrombin III (AT III) in the blood serum of patients and donors. The sensitivity of analysis is 0.6 microgram/ml, time 2 to 3 min. The method is simple, requires no sophisticated equipment, and may be used under field conditions. The results are assessed visually. Immunochemical reagents have been synthesized for the method: latex conjugates and specific antibodies to AT III. The method was tried in patients with peritonitis. An additional criterion for diagnosing the respiratory distress syndrome of adults in this patient population has been developed.

  16. Latex agglutination: diagnose the early cryptococcus neoformans test of capsular polysaccharide antigen.

    PubMed

    Wang, Huanrong; Yuan, Xueqian; Zhang, Lifeng

    2015-01-01

    This paper aims to discuss the early diagnosis value of latex agglutination test in Cryptococcal meningitis. The cerebrospinal fluid (CSF) of 112 patients with definite Cryptococcal meningitis and 26 patients with tubercular meningitis and virus meningitis were collected, latex agglutination test is adopted to detect Cryptococcal capsular polysaccharide antigen. Then it was compared with fungal culture and direct microscopy method for evaluating the sensitivity and specificity of the diagnosis. The sensitivity of three methods including latex agglutination test, fungal culture and direct microscopy was 91.1%,69.6% and 73.2% respectively. The specificity of latex agglutination test was 96.0%, 100% and 100% respectively. That latex agglutination test to detect Cryptococcal capsular polysaccharide antigen could be taken as the early diagnostic method of Cryptococcus neoformans meningitis.

  17. Interaction of bacterial endotoxine (lipopolysaccharide) with latex particles: application to latex agglutination immunoassays.

    PubMed

    Peula-García, J M; Molina-Bolivar, J A; Velasco, J; Rojas, A; Galisteo-González, F

    2002-01-15

    The latex agglutination immunoassay technique uses polymer colloids as carriers for antibodies or antigens to enhance the immunological reaction. In this work, the interaction of a lipopolysaccharide (LPS) of Brucella Melitensis with two conventional latexes has been studied. Some experiments on the physical adsorption of the LPS onto these polystyrene beads have been performed and several complexes with different coverage degrees were obtained by modifying the incubation conditions. Regarding the application in the development of diagnostic test systems, it is advisable to study the latex-LPS complexes from an electrokinetic and colloidal stability point of view. The complexes were electrokinetically characterized by measuring the electrophoretic mobility under different redispersion conditions. The colloidal stability was determined by simple turbidity measurements. Experimental and theoretical data have been employed to study the molecular disposition of the LPS in the latex particle surface to compare with the outer membrane of bacterial cells. Latex complexes covered by different LPS amounts showed high colloidal stability and adequate immunoreactivity that remains for a long time period.

  18. Comparison of genomic and antimicrobial resistance features of latex agglutination test-positive and latex agglutination test-negative Staphylococcus aureus isolates causing bovine mastitis.

    PubMed

    Moser, A; Stephan, R; Corti, S; Johler, S

    2013-01-01

    The dairy industry suffers massive economic losses due to staphylococcal mastitis in cattle. The Staphaureux latex agglutination test (Oxoid, Basel, Switzerland) was reported to lead to negative results in 54% of bovine Staphylococcus aureus strains, and latex-negative strains are thought to be less virulent than Staphaurex latex-positive strains. However, comparative information on virulence and resistance profiles of these 2 groups of Staph. aureus is scarce. Our objective was to associate the latex agglutination phenotype of Staph. aureus strains isolated from bovine mastitis milk with data on clonal complexes, virulence genes, and antibiotic resistance to (1) determine the virulence profiles of the Staphaureux test positive and Staphaurex test negative groups, and (2) provide data needed to improve treatment of bovine mastitis and to identify potential vaccine targets. Seventy-eight Staph. aureus strains isolated from 78 cows on 57 Swiss farms were characterized. Latex agglutination was tested by Staphaureux kit, and resistance profiles were generated by disk diffusion. A DNA microarray was used to assign clonal complexes (CC) and to determine virulence and resistance gene profiles. By the Staphaureux test, 49% of the isolates were latex-positive and 51% were latex-negative. All latex-negative strains were assigned to CC151, whereas latex-positive strains were assigned to various clonal complexes, including CC97 (n=16), CC8 (n=10), CC479 (n=5), CC20 (n=4), CC7 (n=1), CC9 (n=1), and CC45 (n=1). Although the latex-negative isolates were susceptible to all antimicrobial agents tested, 24% of latex-positive isolates were classified as intermediate with regard to cefalexin-kanamycin and 13% were resistant to both ampicillin and penicillin. Microarray profiles of latex-negative isolates were highly similar, but differed largely from those of latex-positive isolates. Although the latex-negative group lacked several enterotoxin genes and sak, it exhibited significantly

  19. [Methicillin resistance detection in Staphylococcus aureus: comparison between conventional methods and MRSA-Screen latex agglutination technique].

    PubMed

    Soloaga, R; Corso, A; Gagetti, P; Faccone, D; Galas, M

    2004-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen that has emerged over the last four decades, causing both nosocomial and community-acquired infections. Rapid and accurate detection of methicillin resistance in S. aureus is important for the use of appropriate antimicrobial therapy and for the control of nosocomial spread of MRSA strains. We evaluated the efficiency of conventional methods for detection of methicillin resistance such as the disk diffusion, agar dilution, oxacillin agar screen test, and the latex agglutination test MRSA-Screen latex, in 100 isolates of S. aureus, 79 mecA positive and 21 mecA negative. The MRSA-Screen latex (Denka Seiken, Niigata, Japón), is a latex agglutination method that detects the presence of PLP-2a, product of mecA gene in S. aureus. The PCR of the mecA gene was used as the "gold standard" for the evaluation of the different methods tested. The percentages of sensitivity and specificity were as follows: disk difusión 97 and 100%, agar dilution 97 and 95%, oxacillin agar screen test 100 and 100%, and MRSA-Screen latex, 100 and 100 %. All methods presented high sensitivity and specificity, but MRSA-Screen latex had the advantage of giving a reliable result, equivalent to PCR, in only 15 minutes.

  20. Characterization of two different agglutinators in the latex fixation test, occurring in normal human sera

    PubMed Central

    Klein, F.; Valkenburg, H. A.; Van Zwet, Theda L.; Lafeber, Geertruida J. M.

    1966-01-01

    Using a sensitive modification of the latex fixation test it is possible to detect a small agglutinating effect in about 60 per cent of normal human sera, after these have been heated for 30 minutes at 56°. This was shown to be caused by an IgM globulin with the properties of a rheumatoid factor. The factor is able to react with human IgG globulin and may represent an antibody to the IgG part of circulating antigen—antibody complexes. The heat treatment probably inactivates an inhibitor of the latex fixation reaction. In addition all normal human sera give an agglutination reaction with IgG coated latex at incubation temperatures of 37° or lower. It was shown that these reactions are caused by a thermolabile, non-reducible component with a sedimentation constant of about 10. This component is probably identical with the complement component C'1q. The agglutinating activity was found in the α2—β1 region after electrophoresis of untreated serum, but in the slow γ region after treatment of the serum with EDTA. This kind of agglutination may cause false positive reactions in latex tests which are carried out at 37° or less. ImagesFIG. 1FIG. 3 PMID:4160336

  1. Cross-reactivity in Cryptococcus antigen latex agglutination test in two commercial kits.

    PubMed

    Tone, Kazuya; Umeda, Yoshiko; Makimura, Koichi

    2016-05-01

    This article presents an examination of the cross-reactivity of pathogenic fungi with Cryptococcus neoformans in two commercial Cryptococcus antigen latex agglutination tests performed across 39 fungal strains. Some fungi were newly indicated as Cryptococcus cross-reactive, and the two kits showed differences in cross-reactive fungi.

  2. Case report: false negative serum cryptococcal latex agglutination test in a patient with disseminated cryptococcal disease.

    PubMed

    Navabi, Nazlee; Montebatsi, Milton; Scott, Michelle; Gluckman, Stephen J; Reid, Michael J A

    2015-01-01

    A case of false-negative serum latex agglutination cryptococcal antigen (CRAG) test in a 45-year-old HIV-positive male with Cryptococcus-positive culture is described. The patient was presented to a hospital in Botswana, with breathlessness and a diffuse papular rash. His CD4 count was 25 cells/μL. Despite the suspicion for disseminated cryptococcal disease, an initial serum CRAG latex test was negative. Results of subsequent Indian ink staining, culture of cerebrospinal fluid and skin scrapings, and serum lateral flow immunoassay (LFA) were all positive for Cryptococcus neoformans. There are several possible explanations for the false-negative CRAG latex test. Given the positive LFA result, we speculate that disease may have been caused by Cryptococcus gattii, which is estimated to be responsible for between 15% and 30% of all cryptococcal diseases in Botswana. Reduced sensitivity of CRAG latex assays for detecting C gattii may lead to underdiagnosis of cryptococcal infection.

  3. Preliminary observations on the use of latex agglutination test for the detection of mastitis due to Streptococcus agalactiae in cows.

    PubMed Central

    Daniel, R C; Barnum, D A

    1986-01-01

    A commercial latex agglutination test for the detection of Group B streptococcal antigens was used to detect infection due to Streptococcus agalactiae in whey of bovine milk samples. Fifteen out of 17 known infections were detected, but it was necessary to incubate the wheys at 37 degrees C for 18 hours in nine of the samples. It was found that the latex agglutination test could detect Group streptococcal carbohydrate antigens in whey samples from artificially infected quarters from one to four days after failure to detect the organism on culture or after antibiotic therapy of the affected quarter. PMID:3527389

  4. Use of the protective antigen of Erysipelothrix rhusiopathiae in the enzyme-linked immunosorbent assay and latex agglutination.

    PubMed

    Sato, H; Yamazaki, Y; Tsuchiya, K; Aoyama, T; Akaba, N; Suzuki, T; Yokoyama, A; Saito, H; Maehara, N

    1998-09-01

    To establish a safe and convenient serodiagnostic method for swine erysipelas, a purified protective protein antigen of Erysipelothrix rhusiopathiae, which included a large amount of protective protein (64 kDa protein), was used for enzyme-linked immunosorbent assay (ELISA) and the latex agglutination (LA) test. In the ELISA, the antisera to four different serovars (1a, 2, 5 and 20) of E. rhusiopathiae exhibit a positive reaction, while antisera to other species of bacteria (Listeria monocytogenes, Staphylococcus aureus, Streptococcus suis, Rhodococcus equi and Corynebacterium pseudotuberculosis) exhibit a negative reaction. In the LA test, the antisera to three different serovars (1a, 2 and 5) of E. rhusiopathiae reacted with P64-sensitized latex beads, while the antiserum to serovar 20 (2553 strain) did not. Moreover, the antisera to other species of bacteria (Listeria monocytogenes, Staphylococcus aureus, Streptococcus suis, Rhodococcus equi and Corynebacterium pseudotuberculosis) did not in this test. Comparing the results of the growth agglutination (GA), ELISA and LA tests of 284 swine sera, there was a high degree of correlation among the results. The detection of anti-E. rhusiopathiae antibodies in the GA, ELISA and LA tests were compared using sera from pigs immunized with P64, alkaline extract (AE) and live-cell vaccine (LV). In all three tests, anti-E. rhusiopathiae antibodies could be detected 1 week after immunization. The serum antibody titre as determined by the LA test increased moderately, as did that by the GA test, while that determined by ELISA increased rapidly. These results suggested that ELISA could be used to monitor changes in anti-E. rhusiopathiae antibody titre and the LA test could be used in the screening test for swine erysipelas.

  5. Blood stained cerebrospinal fluid responsible for false positive reactions of latex particle agglutination tests.

    PubMed Central

    Camargos, P A; Almeida, M S; Filho, G L; Batista, K W; Carvalho, A G; Pereira, C L

    1994-01-01

    The accuracy of the latex particle agglutination test (LPAT) was assessed in blood stained cerebrospinal fluid (CSF) specimens from 166 paediatric patients, aged from three months to 13 years. A commercial LPAT kit was used to detect Haemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis A, B, and C soluble antigens. Culture of CSF specimens was used as the standard and all laboratory procedures were performed blind. The mean CSF erythrocyte count was 66,406 cells/mm3 in the cases and 11,560 cells/mm3 in the controls. The sensitivity and the specificity of LPAT were 83.8 and 94.0%, respectively, suggesting that LPAT is a useful diagnostic tool even in blood stained CSF specimens. PMID:7876387

  6. Latex agglutination test for detecting feline panleukopenia virus, canine parvovirus, and parvoviruses of fur animals.

    PubMed Central

    Veijalainen, P M; Neuvonen, E; Niskanen, A; Juokslahti, T

    1986-01-01

    A latex agglutination (LA) test for the detection of parvoviruses of fur animals, cats, and dogs was developed, and its sensitivity and specificity were compared with those of hemagglutination (HA) and the enzyme-linked immunosorbent assay (ELISA). Tissue culture isolation was used to confirm the specificity results. Fecal samples from various sources were tested, including specimens from raccoon dogs and mink which were experimentally infected with parvoviruses by oral exposure. LA compared favorably with the other tests. The ELISA was the most sensitive. When it was considered as a reference test, the corresponding sensitivities for HA and LA were 96 and 91%, respectively. The specificities were 93% for the ELISA, 95% for the HA test, and 92% for the LA test. LA seems to be a suitable technique for screening animals in the field and in laboratories in which sophisticated techniques are not available. PMID:3007568

  7. Usefulness of PCR and Antigen Latex Agglutination Test with Samples Obtained by Transthoracic Needle Aspiration for Diagnosis of Pneumococcal Pneumonia

    PubMed Central

    García, Amparo; Rosón, Beatriz; Pérez, José Luis; Verdaguer, Ricard; Dorca, Jordi; Carratalà, Jordi; Casanova, Aurora; Manresa, Frederic; Gudiol, Francesc

    1999-01-01

    In a large number of cases, the etiology of community-acquired pneumonia (CAP) is not established. Some cases are probably caused by Streptococcus pneumoniae. Transthoracic needle aspiration (TNA) culture has a limited sensitivity which might be improved by antigen detection or gene amplification techniques. We evaluated the capacity of a PCR assay and a latex agglutination test to detect S. pneumoniae in samples obtained by TNA from 95 patients with moderate-to-severe CAP. Latex agglutination and PCR had sensitivities of 52.2 and 91.3%, specificities of 88.7 and 83.3%, positive predictive values of 62.3 and 65.6%, and negative predictive values of 83.3 and 96.5%, respectively, when culture techniques were used as the “gold standard.” When we considered expanded criteria for the diagnosis of pneumococcal pneumonia as a standard for our calculations, latex agglutination and PCR had sensitivities of 53.6 and 89.7%, specificities of 93.0 and 90.0%, positive predictive values of 78.9 and 81.3%, and negative predictive values of 80.3 and 94.7%, respectively. The additional diagnosis provided by the PCR assay compared to latex agglutination was 12.2% (95% confidence interval of the difference from 0.4 to 20.1%). PCR was more sensitive than TNA culture, particularly in patients who had received prior antibiotic therapy (83.3 versus 33.3%). Although PCR is a very sensitive and specific technique, it has not proved to be cost-effective in clinical practice. Conversely, latex agglutination is a fast and simple method whose results might have significant implications for initial antibiotic therapy. PMID:9986837

  8. Evaluation of a C-reactive protein latex agglutination detection test with sera from patients with sexually transmitted diseases.

    PubMed Central

    Schalla, W O; Arko, R J; Thompson, S E

    1984-01-01

    A total of 149 sera, including 79 pre- and posttreatment sera from 33 patients with disseminated gonococcal infections, 18 from patients with uncomplicated gonococcal infections, 6 from patients with pelvic inflammatory disease, 4 from patients with genital Chlamydia trachomatis infections, and 42 from normal volunteers, were examined for C-reactive protein with a latex agglutination C-reactive protein detection kit (Difco Laboratories, Detroit, Mich.). Results were quantitated with LC-Partigen C-reactive protein radial immuno-diffusion plates (Calbiochem-Behring, La Jolla, Calif.). Positive latex agglutination results were observed in all of the pretreatment sera and some of the posttreatment sera of patients with disseminated gonococcal infections and in two sera from patients with pelvic inflammatory disease, which corresponded to quantitative C-reactive protein levels in the radial immunodiffusion plates. C-reactive protein levels were not detectable in the serum samples from normal volunteers or patients with uncomplicated gonococcal infections or genital chlamydial infections. Positive latex agglutination occurred as early as 20 s in sera with high C-reactive protein levels, and all positive results were observed within 90 s of the 3-min test limit. Positive latex test results were obtained with C-reactive protein levels as low as 1 mg/dl (10 micrograms/ml). PMID:6440907

  9. Direct appraisal of latex agglutination testing, a convenient alternative to enzyme immunoassay for the detection of rotavirus in childhood gastroenteritis, by comparison of two enzyme immunoassays and two latex tests.

    PubMed Central

    Sambourg, M; Goudeau, A; Courant, C; Pinon, G; Denis, F

    1985-01-01

    During February and March 1984, 207 fecal samples from infants and children with gastroenteritis were tested for rotavirus with four techniques: two enzyme immunoassays (Rotazyme; Abbott Laboratories, North Chicago, Ill., and Enzygnost-Rotavirus; Calbiochem-Behring, La Jolla, Calif.) and two latex agglutination tests (Rotalex; Orion Research, Inc., Cambridge, Mass., and Slidex Rota-Kit; Biomérieux). All stool samples were also tested for yeasts and bacterial pathogens. Electron microscopy was used to investigate discrepant results. We found 47% positive samples with Enzygnost-Rotavirus, 38% with Rotazyme, 37% with Slidex Rota-Kit, and 34% with Rotalex. No specimen was found positive by Rotazyme only or Slidex Rota-Kit only. On the contrary, 12 samples which were positive with Enzygnost-Rotavirus only and 3 which were positive with Rotalex only were not confirmed as positive by electron microscopy. Both enzyme immunoassays gave 6% equivocal results; Slidex Rota-Kit gave significantly fewer equivocal results than did Rotalex: 2.9% versus 9.7% (P less than 0.01). The sensitivity and specificity of latex tests compared favorably with that of enzyme immunoassays. Latex agglutination tests can be performed by unskilled personnel and are rapid and relatively cheap. They appear to be very suitable for routine laboratory work and may prove useful for large-scale screening in developing countries. PMID:2985650

  10. Direct appraisal of latex agglutination testing, a convenient alternative to enzyme immunoassay for the detection of rotavirus in childhood gastroenteritis, by comparison of two enzyme immunoassays and two latex tests.

    PubMed

    Sambourg, M; Goudeau, A; Courant, C; Pinon, G; Denis, F

    1985-04-01

    During February and March 1984, 207 fecal samples from infants and children with gastroenteritis were tested for rotavirus with four techniques: two enzyme immunoassays (Rotazyme; Abbott Laboratories, North Chicago, Ill., and Enzygnost-Rotavirus; Calbiochem-Behring, La Jolla, Calif.) and two latex agglutination tests (Rotalex; Orion Research, Inc., Cambridge, Mass., and Slidex Rota-Kit; Biomérieux). All stool samples were also tested for yeasts and bacterial pathogens. Electron microscopy was used to investigate discrepant results. We found 47% positive samples with Enzygnost-Rotavirus, 38% with Rotazyme, 37% with Slidex Rota-Kit, and 34% with Rotalex. No specimen was found positive by Rotazyme only or Slidex Rota-Kit only. On the contrary, 12 samples which were positive with Enzygnost-Rotavirus only and 3 which were positive with Rotalex only were not confirmed as positive by electron microscopy. Both enzyme immunoassays gave 6% equivocal results; Slidex Rota-Kit gave significantly fewer equivocal results than did Rotalex: 2.9% versus 9.7% (P less than 0.01). The sensitivity and specificity of latex tests compared favorably with that of enzyme immunoassays. Latex agglutination tests can be performed by unskilled personnel and are rapid and relatively cheap. They appear to be very suitable for routine laboratory work and may prove useful for large-scale screening in developing countries.

  11. Quantitative capillary reversed passive latex agglutination test for C-reactive protein (CRP) in the dog.

    PubMed

    Tagata, K; Yokoyama, S; Ginbo, T; Honda, M; Okimura, T; Odakura, M; Nomura, M; Yamamoto, S

    1996-01-01

    A capillary reversed passive latex agglutination test (capillary RPLA) was developed which allows quantification of serum C-reactive protein (CRP) within approximately 15 min. The logarithmic regression line (calibration curve) obtained after measuring each CRP concentration three times in twofold dilutions of a standard canine serum containing 222 micrograms/ml of CRP was y = 6.394 + 0.030x (r = 0.995). Capillary RPLA permitted quantification of CRP in the range 6.9-222 micrograms/ml. The coefficients of variation ranged from 10.28% to 12.40%. The recovery rates (percentage recovery) of CRP by capillary RPLA were within the range 87% to 106%. On measuring the CRP concentrations in sera from 78 dogs by capillary RPLA, single radial immunodiffusion (SRID) and enzyme-linked immunosorbent assay (ELISA), close correlations were demonstrated between SRID and capillary RPLA (y = 7.250 + 1.109x, r = 0.978), between SRID and ELISA (y = 3.042 + 1.059x, r = 0.967), and between capillary RPLA and ELISA (y = 1.778 + 0.929x, r = 0.962). Capillary RPLA may be considered useful as a routine biochemical technique for measurement of serum CRP concentration in the dog.

  12. A particle agglutination assay for rapid identification of heparin binding to coagulase-negative staphylococci.

    PubMed

    Pascu, C; Hirmo, S; Ljungh, A; Wadström, T

    1996-10-01

    The heparin-binding properties of six different species of coagulase-negative staphylococci were examined by a particle agglutination assay. Heparin (mol. wt 4000-6000), mildly treated with sodium periodate, was covalently coupled to amino-modified latex beads (0.72 micron diameter). The particle agglutination assay was validated by comparing results with the adhesion (percentage binding of adherent cells) of coagulase-negative staphylococcal strains to heparinised microtitration plates. Of 38 different coagulase-negative staphylococcal strains tested, 30 showed agglutination reactivity with heparin-coated latex beads. Strains of different coagulase-negative staphylococcal species agglutinated heparin-coated latex beads to various extents (e.g., cells of Staphylococcus haemolyticus strains reacted more strongly than cells of S. epidermidis strains). The agglutination reaction was significantly inhibited by fucoidan, suramin, lambda-carrageenan and other sulphated compounds, but not by non-sulphated carbohydrate polymers such as hyaluronic acid. Agglutination of staphylococcal cells with heparin-coated latex beads was completely blocked by a cell-surface extract. These results suggest that structures responsible for heparin binding are exposed on the cell surface.

  13. Validation studies of the latex agglutination test for the detection of Trichinella larvae in meat products.

    PubMed

    Gayda, Jennifer; Reckinger, Sabine; Thaben, Nora; Nöckler, Karsten; Mayer-Scholl, Anne

    2016-11-15

    Human trichinellosis is a foodborne disease caused by ingestion of meat infected with Trichinella muscle larvae. To control Trichinella spp. infection in the European Union, all slaughtered pigs from holdings that are not officially recognized as applying controlled housing conditions and other animals susceptible to Trichinella infection and intended for human consumption should be examined by one of the approved digestion methods described in Regulation (EU) No. 2015/1375. In the past, Trichinella outbreaks due to the consumption of cured wild boar or pork products have been described in several European countries, making the identification of the larvae from these products relevant for Trichinella control. Therefore, this study aimed to validate the newly approved latex agglutination test (Trichin-L) for routine testing of cured meat products. The test was validated based on the OIE Guidelines using pork products spiked with Trichinella larvae. The sensitivity of the method varied greatly depending on the investigated meat product and was usually lower than for the gold standard, the magnetic stirrer method. The detection rate reached 80% for three larvae and 60% for one larva in cured pork sausages. A detection rate of 100% for three larvae and 50% for one larva was found in bacon. For frozen samples (-20°C) the Trichin-L kit is similarly sensitive as for cured samples. Further, to determine the performance of the test under field conditions, pork products from regions with known high Trichinella prevalences confiscated by customs authorities at two German international airports were analyzed. Problems associated with the Trichin-L test were incomplete digestion due to fatty ingredients, spices and very dry meat products, resulting in data which could not be evaluated. Therefore, the test is currently not suitable for the detection of Trichinella larvae in cured meat products and needs further adaptation steps to increase both usability and sensitivity.

  14. Development of a peptide based latex agglutination assay for serotype identification of foot and mouth disease virus.

    PubMed

    Kaur, Dilpreet; Kaur, Gurpreet; Chandra, Mudit; Saxena, Hari M; Dwivedi, Padam N

    2013-02-01

    Out of 200 serum samples collected from cattle (142) and buffaloes (58) of various ages and sexand subjected to latex agglutination test (LAT) using serotype specific peptides (O, A, Asia 1) and also with peptide for non-structural protein 2B (NSP-2B), 114 (70%) samples were positive against FMDV type 'O', 102 (51%) against serotype 'A' and 104 (52%) against serotype 'Asia 1'. With NSP-2B peptide a total of 71 (35.5%) samples were positive. The results suggest that LAT could be used for the diagnosis of foot and mouth disease virus as it is easy, cheap and effective test.

  15. Development and assessment of a latex agglutination test based on recombinant MSP5 to detect antibodies against Anaplasma marginale in cattle

    PubMed Central

    Ramos, Carlos A.N.; Araújo, Flábio R.; Santos, Rafaelle C.; Melo, Elaine S.P.; Sousa, Letícia C.; Vidal, Carlos E.S.; Guerra, Neurisvan R.; Ramos, Rafael A.N.

    2014-01-01

    The recombinant protein MSP5 has been established as an important antigen for serological diagnosis of Anaplasma marginale by enzyme-linked immunosorbent assay (ELISA). However, due to the high cost of specialized equipment, this technique is not accessible to all laboratories, especially in developing countries in areas where the disease is endemic. The present study describes the standardization of a latex agglutination test (LAT) to detect antibodies against A. marginale based on recombinant MSP5. Compared with indirect enzyme-linked immunosorbent assay (iELISA), the relative sensitivity and specificity of the LAT were 95.21% and 91.86% respectively, with an almost perfect agreement between tests (kappa index = 0.863). These results can be considered important for the serological diagnosis of A. marginale, as they indicate that the test represents a rapid and low cost alternative to ELISA. PMID:24948931

  16. Development and assessment of a latex agglutination test based on recombinant MSP5 to detect antibodies against Anaplasma marginale in cattle.

    PubMed

    Ramos, Carlos A N; Araújo, Flábio R; Santos, Rafaelle C; Melo, Elaine S P; Sousa, Letícia C; Vidal, Carlos E S; Guerra, Neurisvan R; Ramos, Rafael A N

    2014-01-01

    The recombinant protein MSP5 has been established as an important antigen for serological diagnosis of Anaplasma marginale by enzyme-linked immunosorbent assay (ELISA). However, due to the high cost of specialized equipment, this technique is not accessible to all laboratories, especially in developing countries in areas where the disease is endemic. The present study describes the standardization of a latex agglutination test (LAT) to detect antibodies against A. marginale based on recombinant MSP5. Compared with indirect enzyme-linked immunosorbent assay (iELISA), the relative sensitivity and specificity of the LAT were 95.21% and 91.86% respectively, with an almost perfect agreement between tests (kappa index = 0.863). These results can be considered important for the serological diagnosis of A. marginale, as they indicate that the test represents a rapid and low cost alternative to ELISA.

  17. Macroscopic Agglutination Test for Rapid Diagnosis of Human Leptospirosis

    PubMed Central

    Brandão, Angela P.; Camargo, Eide D.; da Silva, Emilson D.; Silva, Marcos V.; Abrão, Rui V.

    1998-01-01

    A commercially available slide agglutination test (SAT) for the diagnosis of human leptospirosis was evaluated by comparing it to an immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) and to the microscopic agglutination test (MAT). For all 108 patients, leptospirosis was diagnosed on the basis of a fourfold or greater increase in titer by MAT (seroconversion), and all but 1 of 245 controls were MAT negative (titers, <1:100). Both SAT and the IgM ELISA failed to detect one case of infection (sensitivity, 99%). Only 3 of 145 blood donors and none of the 100 patients with other illnesses were SAT positive (specificity, 99%). The overall results were similar for the three tests; however, SAT and ELISA were statistically more sensitive as initial screening tests. For 22% of the patients, the diagnosis of leptospirosis was made earlier by SAT than by MAT. SAT detected 27 (44%) of 62 MAT-negative patients with the first serum sample. ELISA and SAT had very similar results. Follow-up of patients for 1 year after the onset of symptoms showed a decreasing rate of positivity by SAT from the third month on. The rate of positivity by ELISA decreased more slowly, to about 67% by the end of the study. By MAT all patients were persistently reactive. SAT and ELISA seem to be convenient methods for the rapid and early screening for leptospirosis and could replace the less sensitive MAT. ELISA gives less subjective results than SAT and provides information on IgM kinetics, but it can be performed only by the more sophisticated laboratories. SAT is inexpensive, can be performed more quickly and more easily than ELISA, and could be used by the less well equipped laboratories. PMID:9774553

  18. Prevention of nonspecific reactions on reversed passive latex agglutination assay (RPLA) for detecting low amounts of staphylococcal enterotoxins.

    PubMed

    Pereira, M L; Heneine, L G; Santos, E J; Carmo, L S; Pereira, J L; Bergdoll, M S

    1997-01-01

    The SET-RPLA, from Denka Seiken Co. Ltd., Tokio, a commercial reversed passive latex agglutination test kit, has been recommended to establish the enterotoxicity capacity of some staphylococcal strains, implicated in food poisoning outbreaks that produce low levels of enterotoxins (SE). Despite the RPLA specificity, the occurrence of nonspecific reactions when testing low-SE-producing is common. In order to control these nonspecific reactions the addition of purified normal rabbit IgG purified was applied on approximately 350 staphylococcal isolates from human milk and anatomic sites of healthy dental student carriers. The results indicated that addition of 5% (v/v) of purified normal rabbit IgG (0.74 mg/mL) to the culture supernatant fluid is a simple and reliable tool for the controlling of nonspecific reactions in the RPLA assay.

  19. Evaluation of Pyloriset Dry, a new rapid agglutination test for Helicobacter pylori antibody detection.

    PubMed Central

    Lozniewski, A; De Korwin, J D; Conroy, M C; Plenat, F; Weber, M

    1996-01-01

    We evaluated the performance of a new latex agglutination test, Pyloriset Dry (Orion Diagnostica, Espoo, Finland), in the simultaneous detection of immunoglobulin G (IgG), IgA, and IgM antibodies to Helicobacter pylori and compared it with that of the Pyloristat test (BioWhittaker, Fontenay-sous-Bois, France), an enzyme-linked immunosorbent assay detecting IgG to H. pylori, for 96 untreated dyspeptic patients who had undergone gastroduodenal endoscopy. Infection was diagnosed in 56 cases by positive culture and/or positive Giemsa stain and rapid urease test (antral biopsies) and was associated with chronic gastritis in 52 patients. Forty noninfected patients did not have chronic gastritis. The sensitivity of Pyloriset Dry was 91.1%. The sensitivity of Pyloristat was 91.1 or 82.1%, depending on whether equivocal results were considered positive or negative, respectively. Both tests had a specificity of 87.5%. Their performances were not statistically different. Thus, Pyloriset Dry is an alternative to serological tests for adults, particularly when a small number of serum samples has to be tested. PMID:8784587

  20. Specificity of quantitative latex agglutination assay for D-dimer in exclusion of pulmonary embolism in the emergency department.

    PubMed

    Stein, Paul D; Matta, Fadi; Sabra, Michel J; Tana, Christopher; Gough, Andrew; Chabala, Steve; Kakish, Edward; Tworek, Joseph

    2014-11-01

    We assessed the prevalence of elevated quantitative latex agglutination assay for D-dimer in patients in the emergency department in whom pulmonary embolism (PE) was excluded. D-dimer was normal (<230 ng/mL) in 435 (83%) of the 522 patients. D-dimer was normal in 88% of the patients with musculoskeletal or related chest pain, 74% with pleurisy or pleuritic chest pain, and 85% with upper respiratory tract infection. D-dimer was 230 to 500 ng/mL in 65 (75%) of the 87 in whom D-dimer was elevated. Clinical probability was low in 31 (48%) of the 65 patients with D-dimer levels of 230 to 500 ng/mL. D-dimer was 230 to 500 ng/mL and clinical probability was low in 31 (36%) of the 87 patients who had computed tomographic (CT) angiograms because of elevated D-dimer. Negative likelihood ratio for PE is sufficiently low that PE can be excluded with reasonable certainty in such patients. Tailoring cutoff value to 500 ng/mL in patients with low clinical probability would have reduced CT angiograms by 36%.

  1. Improved detection of nasopharyngeal cocolonization by multiple pneumococcal serotypes by use of latex agglutination or molecular serotyping by microarray.

    PubMed

    Turner, Paul; Hinds, Jason; Turner, Claudia; Jankhot, Auscharee; Gould, Katherine; Bentley, Stephen D; Nosten, François; Goldblatt, David

    2011-05-01

    Identification of Streptococcus pneumoniae in the nasopharynx is critical for an understanding of transmission, estimates of vaccine efficacy, and possible replacement disease. Conventional nasopharyngeal swab (NPS) culture and serotyping (the WHO protocol) is likely to underestimate multiple-serotype carriage. We compared the WHO protocol with methods aimed at improving cocolonization detection. One hundred twenty-five NPSs from an infant pneumococcal-carriage study, containing ≥ 1 serotype by WHO culture, were recultured in duplicate. A sweep of colonies from one plate culture was serotyped by latex agglutination. DNA extracted from the second plate was analyzed by S. pneumoniae molecular-serotyping microarray. Multiple serotypes were detected in 11.2% of the swabs by WHO culture, 43.2% by sweep serotyping, and 48.8% by microarray. Sweep and microarray were more likely to detect multiple serotypes than WHO culture (P < 0.0001). Cocolonization detection rates were similar between microarray and sweep, but the microarray identified the greatest number of serotypes. A common serogroup type was identified in 95.2% of swabs by all methods. WHO methodology significantly underestimates multiple-serotype carriage compared to these alternate methods. Sweep serotyping is cost-effective and field deployable but may fail to detect serotypes at low abundance, whereas microarray serotyping is more costly and technology dependent but may detect these additional minor carried serotypes.

  2. Collaborative evaluation of antigen detection by a commercial latex agglutination test and enzyme immunoassay in the diagnosis of invasive candidiasis.

    PubMed Central

    Lemieux, C; St-Germain, G; Vincelette, J; Kaufman, L; de Repentigny, L

    1990-01-01

    The Cand-Tec Candida detection system and enzyme immunoassay for serum mannan were retrospectively compared in a controlled collaborative evaluation of antigen detection in 32 patients with candidiasis proven by biopsy or culture from a normally sterile site and with sera drawn within 7 days of inclusion. With a threshold titer of 1/8, which excluded false-positive results in 17 hospitalized patients without candidiasis, sensitivities for all 32 patients with candidiasis were 44% for the Cand-Tec assay and 17% for the enzyme immunoassay. Both assays provided greater sensitivity when sera were drawn within 24 h of inclusion in the study and in the category of patients with invasive candidiasis (57% by Cand-Tec and 33% by enzyme immunoassay). The Cand-Tec assay gave false-positive results (titer, greater than or equal to 1/8) in 4 of 6 patients with transient candidemia, in 1 of 20 otherwise healthy patients with rheumatoid factor, and in 1 patient with a positive cryptococcal latex agglutination test. Three serum specimens from 3 of 32 patients with candidiasis contained rheumatoid factor and gave titers of greater than or equal to 1/8 by the Cand-Tec assay. Detection of serum mannan by enzyme immunoassay was less sensitive but more specific than the Cand-Tec Candida detection system for the diagnosis of invasive candidiasis. PMID:2179258

  3. Latex agglutination test

    MedlinePlus

    ... the results of this test. Normal Results Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider ...

  4. Evaluation of latex reagents for rapid identification of Candida albicans and C. krusei colonies.

    PubMed Central

    Freydiere, A M; Buchaille, L; Guinet, R; Gille, Y

    1997-01-01

    A total of 322 yeast strains and yeastlike organisms belonging to the genera Candida, Cryptococcus, Geotrichum, Saccharomyces, and Trichosporon were tested with the new monoclonal antibody-based Bichro-latex albicans and Krusei color latex tests. Comparison of results with those obtained by conventional identification methods showed 100% sensitivity for both latex tests and 100% and 95% specificity for the Bichro-latex albicans and Krusei color tests, respectively. Because the test is easy to read and quick to perform, the Bichro-latex albicans test may be useful for rapid identification of Candida albicans colonies in the clinical laboratory. PMID:9157146

  5. Rapid detection of methicillin-resistant Staphylococcus aureus strains not identified by slide agglutination tests.

    PubMed Central

    Kuusela, P; Hildén, P; Savolainen, K; Vuento, M; Lyytikäinen, O; Vuopio-Varkila, J

    1994-01-01

    Seventy-nine methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated during 1980 to 1990, were classified as MRSA Aggl- (14 strains) and MRSA Aggl+ (65 strains) strains on the basis of test results in slide agglutination assays designed to detect fibrinogen-binding protein (clumping factor) and protein A on the staphylococcal surface. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that lysostaphin digests of MRSA Aggl- strains contained a high-molecular-weight protein which was not detected in digests of MRSA Aggl+ strains. Immunization of rabbits with an MRSA Aggl- strain produced an antiserum which agglutinated all MRSA Aggl- strains and also 64 of 65 MRSA Aggl+ strains. Only 1 of 68 coagulase-negative staphylococci showed agglutination in this assay. The anti-MRSA Aggl- antiserum reacted mainly with a 230-kDa staphylococcal surface protein but also with a 175-kDa protein, probably formed by proteolysis of the former and a few slightly smaller proteins. These could not be immunologically detected in lysostaphin digests of MRSA Aggl+ strains. Purified antibodies reacting with the 230-kDa protein agglutinated all MRSA Aggl- strains, indicating that the protein is located on the surfaces of staphylococci. The results suggest a tentative role for the 230-kDa protein or its fragments as a novel target to develop more efficient rapid identification methods for S. aureus, including MRSA. Images PMID:8126170

  6. Latex agglutination assays for detection and of non-O157 Shiga toxin-producing E. coli serogroups O26, O45, O103, O111, O121 and O145

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Latex agglutination assays were developed for the top six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups utilizing polyclonal antibodies. Rabbit antisera were affinity purified through Protein A/G columns and the isolated immunoglobulins (IgG) were covalently immobilized onto pol...

  7. Comparison of the H7 latex agglutination test with a fliCh7 real-time PCR assay for confirmation of the H type of Escherichia coli O157:H7

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli O157:H7 is a food-borne pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome. Positive identification of E. coli O157:H7 is made using biochemical tests and latex agglutination using specific antisera. However, under certain conditions, some E. coli O157:H7 isolate...

  8. Evaluation of chromogenic medium and direct latex agglutination test for detection of group B streptococcus in vaginal specimens from pregnant women in Lebanon and Kuwait.

    PubMed

    Ghaddar, Nahed; Alfouzan, Wadha; Anastasiadis, Elie; Al Jiser, Tamima; Itani, Saad Eddine; Dernaika, Racha; Eid, Toufic; Ghaddar, Ali; Charafeddine, Adib; Dhar, Rita; El Hajj, Hiba

    2014-10-01

    This study was undertaken to evaluate chromogenic medium and a direct latex agglutination test (DLA) for detection of Group B Streptococcus (GBS) in the vaginal specimens of pregnant women, and to ascertain the prevalence of GBS in this population in Kuwait and Lebanon. Vaginal swabs, collected from women at 35-37 weeks of gestation, were cultured on 5 % sheep blood agar (SBA), colistin nalidixic acid agar (CNA), Strept B Select chromogenic agar (SBS) as well as Lim enrichment broth in 168 cases in Lebanon while only SBA was used for 1391 samples in Kuwait. In addition, vaginal samples from 102 GBS-positive and 20 GBS-negative women near the time of delivery were collected in Kuwait for evaluation of the DLA test. During the study period, the prevalence of GBS colonization was determined to be 20.7 % (288/1391) in Kuwait while 18.4 % (31) of 168 pregnant women in Lebanon had vaginal cultures positive for GBS. By direct plating of vaginal swabs on the three media used, the isolation rates of GBS were 51.6, 64.5 and 77.4 % on SBA, CNA and SBS, respectively, which increased to 90.35, 93.1 and 96.8 %, respectively, following subculture in Lim broth after 18 h of incubation. The sensitivity of the DLA test was found to be dependent on the density of GBS colonization, resulting in 100 % sensitivity and 100 % specificity for heavy (>10(2) c.f.u. per swab) and moderately heavy (50-100 c.f.u. per swab) growth of GBS. However, for vaginal specimens yielding <50 c.f.u. per swab, the sensitivity, specificity, positive and negative predictive values of the DLA test were 100, 55.5, 63.6 and 100 %, respectively. In conclusion, a chromogenic agar, such as SBS, and a DLA test can be used for rapid detection of GBS in pregnant women. The DLA test, in particular, could prove to be a useful tool for immediate detection of GBS in women near delivery so that intrapartum antibiotic prophylaxis can be initiated.

  9. Development of the reverse passive latex agglutination method for the detection and quantification of the genus Nitrospira in the wastewater treatment process.

    PubMed

    Okumura, Takekazu; Nagai, Fumiko; Yamamoto, Shuta; Hashimoto, Toshikazu; Ito, Masahiko; Sawada, Haruji

    2008-02-01

    This report describes a new immunological method for the detection and quantification of Nitrospira populations using the reverse passive latex agglutination (RPLA). The numbers of the genus Nitrospira have been quantified only by molecular biological techniques such as FISH and quantitative PCR to date. Using high-density latex particles and a specific polyclonal antibody, Nitrospira populations in the wastewater treatment process were quantified in the shortest 4 h of incubation. The minimum detectable number of Nitrospira cells was 7.0x10(5) (log(10) 5.85) cells/ml. It is thought that the RPLA method can quantify Nitrospira populations more simply, economically, and speedily than molecular biological techniques or the culture method, because this procedure has a simple protocol and does not require the use of specialized equipment, expensive reagents, or technical skill. Therefore it is applicable for use in the everyday control and maintenance of water quality in wastewater treatment facilities where equipment is not sufficient or in the field.

  10. Effect of rapid set binder on early strength and permeability of HES latex modified road repair pre-packed concrete

    NASA Astrophysics Data System (ADS)

    Han, J. W.; Lee, S. K.; Yu, C.; Park, C. G.

    2015-12-01

    The early strength development characteristics and permeability resistance of high early strength (HES) pre-packed road repair concrete incorporating a rapid-set binder material were evaluated for emergency repairs to road pavement. The rapid-set binder is a mixture of rapid-set cement and silica sands whose fluidity improves with the addition of styrene butadiene latex (latex). The resulting mixture has a compressive strength of 21 MPa or higher and a flexural strength of greater than 3.5 MPa after 4 hours, the maximum curing age allowed for emergency repair materials. This study examines the strength development properties and permeability resistance of HES latex-modified pre-packed road repair concrete using a rapid- set binder as a function of the latex-to-binder mixing ratio at values of 0.40, 0.33, 0.29 and 0.25. Both early strength development properties and permeability resistance increased as the ratio of latex to rapid-set binder decreased. The mixture showed a compressive strength of 21 MPa or higher after 4 hours, which is the design standard of emergency repair concrete, only when this ratio was 0.29 or lower. A flexural strength of 3.5 MPa or greater was observed after hours only when this ratio was 0.33 or lower. The standard for permeability resistance, less than 2,000 C of chloride after 7 days of curing, was satisfied by all ratios. The ratio of latex to rapid-set binder satisfying all of the conditions for an emergency road repair material was 0.29 or less.

  11. Latex allergy.

    PubMed

    Gawchik, Sandra M

    2011-01-01

    Allergy to natural rubber latex is an important clinical condition that occurred after the institution of universal precautions to protect healthcare workers. A rapid increase and production of both examination and surgical gloves resulted in an epidemic of allergy to latex protein. Healthcare workers in both the medical and dental environments, as well as specific groups of individuals including those with spina bifida, myelodysplasia, and food allergies (banana, kiwi, avocado, and others), were at increased risk of sensitization. Clinical symptoms in the latex allergic individual ranged from type I hypersensitivity reaction including rhinoconjunctivitis, asthma, and systemic reaction to type IV hypersensitivity reaction, which occur from the chemicals added during the manufacturing process. Diagnosis of latex allergy is based on a clinical history that correlates the development of symptoms in relationship to exposure. In the United States there are no skin tests approved by the Food and Drug Administration. Therefore a combination of clinical judgment and serologic testing such as ImmunoCAP and Immulite is helpful. The primary treatment of latex allergy is avoidance of exposure to the latex protein.

  12. Latex Allergy

    MedlinePlus

    ... a milky fluid that comes from the tropical rubber tree. Hundreds of everyday products contain latex. Repeated ... latex. Common latex products include Gloves Condoms Balloons Rubber bands Shoe soles Pacifiers You can find latex- ...

  13. Latex Allergy

    MedlinePlus

    ... for latex allergy. Health care workers who have hay fever have anespecially high chance of developing a latex ... as 25% of all health careworkers who have hay fever show signs of being sensitive to latex.People ...

  14. C reactive protein rapid assay techniques for monitoring resolution of infection in immunosuppressed patients.

    PubMed Central

    Harris, R I; Stone, P C; Hudson, A G; Stuart, J

    1984-01-01

    Three rapid assay techniques (latex agglutination, laser nephelometry, and EMIT enzyme immunoassay) have been evaluated for serial monitoring of the serum C reactive protein (CRP) concentration in immunosuppressed patients with fever. Radial immunodiffusion assay was used as a reference method. Latex agglutination reliably distinguished between normal and raised serum CRP concentrations. Enzyme immunoassay also provided a result within minutes, showed particularly close correlation (r = 0.967) with the reference method, and was free from interference by lipaemic or icteric sera. In 27% of 55 episodes of fever studied serially in immunosuppressed patients, the enzyme immunoassay provided clinically useful information by indicating incomplete resolution of infection despite resolution of fever. PMID:6430971

  15. Improving agglutination tests by working in microfluidic channels.

    PubMed

    Degré, G; Brunet, E; Dodge, A; Tabeling, P

    2005-06-01

    Latex agglutination tests are used for the diagnosis of diseases in man and animals. They are generally simple, cheap, and do not require sophisticated equipment, nor highly specialized skills. In this Technical Note, we put latex agglutination tests in a microfluidic format. The experiment is performed in PDMS (polydimethylsiloxane) microchannels, using streptavidin-coated superparamagnetic beads and a magnetic field. The target molecule is biotinylated protein A. By taking full advantage of the microfluidic conditions (scaling down of the detection volume and controlled action of the shear flow), we achieved an analytical sensitivity of 10 fmol l(-1)(several hundreds of fg ml(-1)) and a fast response (a few minutes) ; the test is also quantitative. Performances of agglutination tests can thus be improved by orders of magnitude by adapting them to a microfluidic format; this comes in addition to the usual advantages offered by this technology (integration, high throughput etc.).

  16. [Latex allergy].

    PubMed

    Pacor, M L; Biasi, D; Cortina, P; Maleknia, T; Lunardi, C

    1995-03-01

    In 1979 the first case of contact urticaria to rubber gloves was reported in a patient with a positive skin prick test to latex. The use of articles containing rubber is widespread and this can explain the increasing frequency of allergic reactions to natural rubber latex. The symptoms may be localized like contact urticaria or systemic like angioedema, generalized urticaria or anaphylactic shock. In this study we have considered 12 patients who presented clinical manifestations after direct contact with objects containing rubber. Three patients had eczema and pruritus after the use of household gloves, 4 subjects had lips and tongue oedema following the contact with rubber tube during a dental treatment, 5 patients suffered from urticaria and pruritus during the use of surgical gloves. Generalized angioedema was also present in 4 out of 12 patients. All the patients had positive Skin prick test and Rast to latex. Three out of 12 patients were atopic. Our study confirms the increasing frequency of immediate hypersensitivity reactions to latex. This phenomenon must be taken into account especially before surgery, since severe clinical manifestations such as anaphylactic shock may occur.

  17. UseLATEX.cmake

    SciTech Connect

    Moreland, Kenneth

    2015-10-20

    UseLATEX.cmake is a collection of script functions and examples for building LaTeX documents. It simplifies the process of building LaTeX documents, which requires the execution of multiple programs and the management of several input files. UseLATEX.cmake also provides several options to customize the LaTeX build process.

  18. A simple, rapid and cost-effective process for production of latex clearing protein to produce oligopolyisoprene molecules.

    PubMed

    Andler, R; Steinbüchel, A

    2017-01-10

    Aiming at finding feasible alternatives for rubber waste disposal, the partial enzymatic degradation of poly(cis-1,4-isoprene)-containing materials represents a potential solution. The use of rubber-degrading enzymes and the biotransformation of rubber into new materials is limited by the high costs associated with the production and purification of the enzyme and the complexity of the process. This study presents a simple and low-cost procedure to obtain purified latex clearing protein (Lcp), an enzyme capable of cleaving the double bonds of poly(cis-1,4-isoprene) in presence of oxygen to produce different size of oligomers with terminal aldehyde and ketone groups, respectively. The gene coding for Lcp1VH2 from Gordonia polyisoprenivorans strain VH2 was overexpressed in Escherichia coli C41 (DE3), and by using an auto-induction medium high protein yields were obtained. The cultivation process was described and compared with an IPTG-inducible medium previously used. Purification of the enzyme was performed using salting out precipitation with ammonium sulfate. Different salt concentrations and pH were tested in order to find the optimal for purification, obtaining a concentration of 60mg Lcp per l. The enzymatic activity of the purified enzyme was measured by an oxygen consumption assay in the presence of polyisoprene latex. Volumetric activities of 0.16Uml(-1) were obtained at optimal conditions of temperature and pH. The results showed an active and partial purified fraction of Lcp1VH2, able to cleave the backbone of poly(cis-1,4-isoprene) and to produce degradation products that were identified with staining methodologies (Schiff reagent for aldehyde groups and 2,4-DNPH for carbonyl groups) and characterized using nuclear magnetic resonance (NMR). Thirteen different storage conditions were tested for the purified enzyme analyzing the enzymatic activity after 1 and 3 months. Lcp1VH2, as an ammonium sulfate precipitate, was stable, easy to handle and sufficiently

  19. A role for a Hevea latex lectin-like protein in mediating rubber particle aggregation and latex coagulation.

    PubMed

    Wititsuwannakul, Rapepun; Pasitkul, Piyaporn; Kanokwiroon, Kamonwan; Wititsuwannakul, Dhirayos

    2008-01-01

    An in vitro aggregation of washed lutoid membrane and rubber particles, respectively, prepared from the bottom (lutoid) fraction and rubber layer of centrifuged fresh latex, leading to the formation of rubber coagulum necessary for a latex coagulation was demonstrated. A Triton X-100 extract of washed lutoid membrane proteins, isolated and prepared from the bottom fraction of centrifuged fresh latex was examined for its role in the latex coagulation process. It induced agglutination of rabbit erythrocytes, indicating the presence of a lectin-like protein. Hevea latex lectin-like protein (HLL) was purified to homogeneity by active chitin binding separation, followed by DEAE-Sepharose chromatography. Its M(r) analyzed by SDS-PAGE was 17 kDa, whereas that determined by gel filtration was 267 kDa. The HLL had a pI value of 7.2. Several glycoproteins were shown to inhibit the HLL-induced hemagglutination. The hemagglutinin activity of HLL was enhanced by Ca(2+). Of most interest was the finding that HLL strongly induced aggregation of the Hevea latex rubber particles (RP). This strong RP aggregation leads to latex coagulation, indicating the possibility that it is involved in the formation of the coagulum that plugs the latex vessel ends and stops the flow of latex upon tapping. In addition, the purified HLL also induced aggregation of RP taken from several other non-Hevea latex producing plants. This might indicate either a common or universal role of this lectin-like protein in RP aggregation and hence latex coagulation. This paper, for the first time, provides clear and unequivocal evidence for either a key biological role or physiological function of an endogenous latex lectin-like protein in the sequential process of latex coagulation.

  20. LATEX for Librarians.

    ERIC Educational Resources Information Center

    Boatright, George S.

    This paper presents the basics of "LATEX," a computerized typesetting program popular with mathematicians and other writers of technical papers, and compares it to conventional word processing programs. LATEX, which requires a text editor such as WordPad or NotePad--the text editor is used to produce and input file which the LATEX program…

  1. Real time observation and automated measurement of red blood cells agglutination inside a passive microfluidic biochip containing embedded reagents.

    PubMed

    Huet, Maxime; Cubizolles, Myriam; Buhot, Arnaud

    2016-09-20

    The process of agglutination is commonly used for the detection of biomarkers like proteins or viruses. The multiple bindings between micrometer sized particles, either latex beads or red blood cells (RBCs), create aggregates that are easily detectable and give qualitative information about the presence of the biomarkers. In most cases, the detection is made by simple naked-eye observation of agglutinates without any access to the kinetics of agglutination. In this study, we address the development of a real-time time observation of RBCs agglutination. Using ABO blood typing as a proof-of-concept, we developed i) an integrated biological protocol suitable for further use as point-of-care (POC) analysis and ii) two dedicated image processing algorithms for the real-time and quantitative measurement of agglutination. Anti-A or anti-B typing reagents were dried inside the microchannel of a passive microfluidic chip designed to enhance capillary flow. A blood drop deposit at the tip of the biochip established a simple biological protocol. In situ agglutination of autologous RBCs was achieved by means of embedded reagents and real time agglutination process was monitored by video recording. Using a training set of 24 experiments, two real-time indicators based on correlation and variance of gray levels were optimized and then further confirmed on a validation set. 100% correct discrimination between positive and negative agglutinations was performed within less than 2min by measuring real-time evolution of both correlation and variance indicators.

  2. Evaluation of a rapid von Willebrand factor activity latex immuno assay for monitoring of patients with von Willebrand disease (VWD) receiving DDAVP or VWF replacement therapy.

    PubMed

    Vinayagam, S; Simons, L R; Chowdary, P; Thurlow, P; Brooks, S V; Riddell, A F

    2014-07-01

    Haemostatic management of surgery in patients with von Willebrand disease (VWD) includes DDAVP or von Willebrand factor (VWF)-containing concentrates. Although the recommendations are for monitoring by VWF activity assays, it is quite common for clinicians to use factor VIII due usually to longer turnaround times required for VWF ristocetin cofactor assay (VWF:RCo) measurements. The aim of this study was to evaluate use of the rapid HaemosIL VWF activity (VWF:Act) latex immuno assay (LIA) on an automated coagulometer (ACL TOP(™) 700; Instrumentation Laboratory, Bedford, MA, USA) compared to platelet-based VWF:RCo assays in this setting. One hundred and sixty-seven plasma samples from 42 patients [Type 1 (n = 22), Type 2A (n = 2), Type 2B (n = 3), Type 2M (n = 10), Type 3 (n = 3)] and acquired von Willebrand syndrome (n = 2) with VWD treated with DDAVP or VWF-containing concentrates were included in the study. Method comparison and method bias were evaluated by Bland-Altman analysis (BA) and Passing and Bablok regression modelling respectively. BA of baseline samples (n = 39) showed a mean difference of -3.0 (±1.96 SD -25.2 to +19.4). Post (treatment) samples (n = 120) were separated into two groups. Group 1 contained samples with VWF:RCo levels 10 to ≤175 IU dL(-1) (n = 97) and group 2, samples with VWF:RCo levels >175 IU dL(-1) (n = 23). BA of group 1 postsamples showed a mean difference of +3.4 (±1.96 SD -44.6 to +51.5), and the BA of Group 2 samples was -23.9 (±1.96 SD -136.1 to +88.3). In conclusion, use of HaemosIL VWF:Act LIA test on an automated coagulometer is a reproducible and rapid assay that can be used as an alternative test for monitoring VWF replacement therapy, facilitating dose adjustments on a real-time basis.

  3. Diagnosis of myocardial infarction based on lectin-induced erythrocyte agglutination: a feasibility study

    NASA Astrophysics Data System (ADS)

    Bocsi, József; Nieschke, Kathleen; Mittag, Anja; Reichert, Thomas; Laffers, Wiebke; Marecka, Monika; Pierzchalski, Arkadiusz; Piltz, Joachim; Esche, Hans-Jürgen; Wolf, Günther; Dähnert, Ingo; Baumgartner, Adolf; Tarnok, Attila

    2014-03-01

    Myocardial infarction (MI) is an acute life-threatening disease with a high incidence worldwide. Aim of this study was to test lectin-carbohydrate binding-induced red blood cell (RBC) agglutination as an innovative tool for fast, precise and cost effective diagnosis of MI. Five lectins (Ricinus communis agglutinin (RCA), Phaseolus vulgaris erythroagglutinin (PHA), Datura stramonium agglutinin (DSA), Artocarpus agglutinin (ArA), Triticum agglutinin (TA)) were tested for ability to differentiate between agglutination characteristics in patients with MI (n = 101) or angina pectoris without MI (AP) (n = 34) and healthy volunteers (HV) as control (n =68) . RBC agglutination was analyzed by light absorbance of a stirred RBC suspension in the green to red light spectrum in an agglutimeter (amtec, Leipzig, Germany) for 15 min after lectin addition. Mean cell count in aggregates was estimated from light absorbance by a mathematical model. Each lectin induced RBC agglutination. RCA led to the strongest RBC agglutination (~500 RBCs/aggregate), while the others induced substantially slower agglutination and lead to smaller aggregate sizes (5-150 RBCs/aggregate). For all analyzed lectins the lectin-induced RBC agglutination of MI or AP patients was generally higher than for HV. However, only PHA induced agglutination that clearly distinguished MI from HV. Variance analysis showed that aggregate size after 15 min. agglutination induced by PHA was significantly higher in the MI group (143 RBCs/ aggregate) than in the HV (29 RBC-s/aggregate, p = 0.000). We hypothesize that pathological changes during MI induce modification of the carbohydrate composition on the RBC membrane and thus modify RBC agglutination. Occurrence of carbohydrate-lectin binding sites on RBC membranes provides evidence about MI. Due to significant difference in the rate of agglutination between MI > HV the differentiation between these groups is possible based on PHA-induced RBC-agglutination. This novel assay

  4. Latex allergies - for hospital patients

    MedlinePlus

    ... proteins that are in latex. These foods include bananas, avocado, and chestnuts. Foods that are less strongly ... Asthma and Immunology. Latex Cross-reactive Foods Fact Sheet. Updated October 8, 2015. latexallergyresources.org/latex-cross- ...

  5. Managing latex allergies at home

    MedlinePlus

    ... proteins that are in latex. These foods include: Bananas Avocado Chestnuts Other foods that are less strongly ... Asthma and Immunology. Latex Cross-reactive Foods Fact Sheet. Updated October 8, 2015. latexallergyresources.org/latex-cross- ...

  6. Natural rubber latex allergy.

    PubMed

    Deval, Ravi; Ramesh, V; Prasad, G B K S; Jain, Arun Kumar

    2008-01-01

    Natural rubber latex (NRL) is a ubiquitous allergen as it is a component of > 40,000 products in everyday life. Latex allergy might be attributed to skin contact or inhalation of latex particles. Latex allergy is an IgE-mediated hypersensitivity to NRL, presenting a wide range of clinical symptoms such as angioedema, swelling, cough, asthma, and anaphylactic reactions. Until 1979, latex allergy appeared only as type IV delayed hypersensitivity; subsequently, the proportion of different allergy types drifted towards type IV contact allergy reactions. Several risk factors for sensitization to NRL are already known and well documented. Some authors have established a positive correlation between a history of multiple surgical interventions, atopy, spina bifida malformation, and latex allergy incidence. We suspect an increase in latex allergy incidence in association with increased atopy and sensitivity to environmental allergens in the industrial population. It is often postulated in literature that the groups of workers at risk for this allergy are essentially workers in the latex industry and healthcare professionals. In this population, direct internal and mucosal contact with NRL medical devices may be the route of sensitization as factors such as the number of procedures and use of NRL materials (catheters and tubes) were associated with increased risk of latex sensitization and allergy.

  7. Latex allergy: past and present.

    PubMed

    Meade, B Jean; Weissman, David N; Beezhold, Donald H

    2002-02-01

    Although latex products have been in use for over a century, allergic responses to latex proteins have only been recognized as a serious health problem for the past 15 years. Latex allergy particularly affects two groups, health care workers (HCW) and children with spina bifida (SB). This manuscript provides a brief history of latex allergy, and a review of the following: the manufacturing process for dipped latex products, the 11 latex allergens that have been characterized and received allergen designations by the International Union of Immunological Societies, the methods used in exposure assessment, the epidemiology and clinical management of latex allergy, and the use of animal models in investigating mechanisms underlying latex allergy.

  8. Detection of fibrinogen antigens with two latex techniques applied to urine concentrates

    PubMed Central

    Donati, Maria Benedetta; Semeraro, N.; Vermylen, J.

    1973-01-01

    Fibrinogen antigens were measured either with an agglutination inhibition method (using latex particles coated with fibrinogen; Diagen test) or with a direct agglutination technique (using latex particles coated with a mixture of anti-D and anti-E antibodies; Thrombo-Wellcotest). Both methods were compared with the tanned red cell haemagglutination inhibition immunoassay (TRCHII) during progressive degradation of fibrinogen with plasmin and using purified fibrinogen fragments or urine concentrates from chronic glomerulonephritis or transplanted patients. Due to the different sensitivity of the two latex techniques to fibrinogen and its plasmin derivatives, their combined use may be helpful to distinguish the nature of the fibrinogen-like material excreted in urine. PMID:4201501

  9. Latex allergy in children.

    PubMed

    Niggemann, B; Breiteneder, H

    2000-02-01

    Natural rubber is a component of the latex of the tropical Hevea brasiliensis tree which is widely used in the manufacturing of medical devices and a large variety of articles for everyday use. Over a dozen allergens have been identified in the latex of H. brasiliensis. The allergens Hev b 1, Hev b 3, Hev b 6, and Hev b 7 are proteins that are involved in the biosynthesis of rubber or the coagulation of latex. Allergens that are part of the plant's defense system are represented by Hev b 2 and class I endochitinases. The allergens Hev b 4, Hev b 5, and Hev b 8-10 were classified as either structural or housekeeping proteins. Immediate-type hypersensitivity reactions to proteins present in Hevea latex were first described in 1927. Since then, natural rubber latex (NRL) allergy has become an important medical problem for an increasing number of individuals. Sensitization mainly occurs by wound or mucosal contact with NRL devices during surgery or by inhalation of airborne allergens released from powdered latex gloves. The number of surgical interventions and an atopic disposition are the most important risk factors for developing latex allergy, especially in children with spina bifida. Exposure to NRL products should be carefully avoided for individuals who belong to high-risk groups. Initial studies on establishing a latex-free environment for surgery in all spina bifida patients have reported on a decrease in sensitization and allergy to NRL.

  10. [Latex: a complex allergy].

    PubMed

    Ferreira, M B; Carlos, A G

    1999-01-01

    The authors review several of the most important aspects of latex allergy, an increasing problem in Public Health, which should be understood by all health professionals. After briefly presenting the history of the origin latex, from Hevea brasiliensis the authors describe the antigens of latex: Hev b1 to Hev b8, major allergens. They also note the crossed reactivity not only with foods, exotic fruits, but also with pneumoallergens and in particular the pollens. The groups at risk are essentially workers in the latex industry, health professionals and finally infants with spina bifida or other severe urological anomaly. The clinical signs are reactions of type 1 hypersensitivity, to urticaria and/or angio-oedema and anaphylactic shock. Diagnosis is based on a search for specific serum IgE, skin tests and provocation tests. Prophylaxis depends on removal of all substances that are based on latex, especially replacement of gloves with vinyl, but also on a food diet that excludes all foods that have a cross-reactivity with latex.

  11. Agglutination of Helicobacter pylori coccoids by lectins

    PubMed Central

    Khin, Mar Mar; Hua, Jie Song; Ng, Han Cong; Wadström, Torkel; Ho, Bow

    2000-01-01

    AIM: To study the agglutination pattern of Helicobacter pylori coccoid and spiral forms. METHODS: Assays of agglutination and agglutination inhibition were applied using fifteen commercial lectins. RESULTS: Strong agglutination was observed with mannose-specific Concanavalin A (Con A), fucose-specific Tetragonolobus purpureas (Lotus A) and N-acetyl glucosamine-specific Triticum vulgaris (WGA) lectins. Mannose and fucose specific lectins were reactive with all strains of H. pylori coccoids as compared to the spirals. Specific carbohydrates, glycoproteins and mucin were shown to inhibit H. pylori lectin-agglutination reactions. Pre-treatment of the bacterial cells with formalin and sulphuric acid did not alter the agglutination patterns with lectins. However, sodium periodate treatment of bacterial cells were shown to inhibit agglutination reaction with Con A, Lotus A and WGA lectins. On the contrary, enzymatic treatment of coccoids and spirals did not show marked inhibition of H. pylori lectin agglutination. Interes tingly, heating of H. pylori cells at 60 °C for 1 h was shown to augment the agglutination with all of the lectins tested. CONCLUSION: The considerable differences in lectin agglutination patterns seen among the two differentiated forms of H. pylori might be attributable to the structural changes during the events of morphological transformation, resulting in exposing or masking some of the sugar residues on the cell surface. Possibility of various sugar residues on the cell wall of the coccoids may allow them to bind to different carbohydrate receptors on gastric mucus and epithelial cells. The coccoids with adherence characteristics like the spirals could aid in the pathogenic process of Helicobacter infection. This may probably lead to different clinical outcome of H. pylori associated gastroduodenal disease. PMID:11819557

  12. Blends of guayule natural rubber latex with commercial latex polymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guayule (Parthenium argentatum) is a woody desert shrub that produces natural rubber, cis-1,4 polyisoprene, by biosynthesis. It is currently cultivated in the southwestern United States as a source of latex and rubber for commercial development. Guayule latex is similar to Hevea latex in polymer mo...

  13. Latex Allergy: A Prevention Guide

    MedlinePlus

    ... chemicals added to latex during harvesting, processing, or manufacturing. These chemicals can cause a skin rash similar ... allergy. However, they may reduce reactions to chemical additives in the latex (allergic contact dermatitis). Use appropriate ...

  14. Latex Allergy: Tips to Remember

    MedlinePlus

    ... been reviewed by Thanai Pongdee, MD, FAAAAI Natural rubber latex, a milky fluid found in rubber trees, is used to make some gloves, condoms, balloons, rubber bands, erasers and toys. Latex can also be ...

  15. Ultrasound enhanced detection of individual meningococcal serogroups by latex immunoassay

    PubMed Central

    Sobanski, M A; Vince, R; Biagini, G A; Cousins, C; Guiver, M; Gray, S J; Kaczmarski, E B; Coakley, W T

    2002-01-01

    Aims: To examine A, C, Y, and W135 Neisseria meningitidis serogroup characterisation by ultrasonic standing wave enhanced latex agglutination tests (USELATs) of clinical samples. In addition, to determine USELAT enhancement of detection sensitivity for the individual antigens compared with conventional card latex agglutination tests (LATs). Methods: Wellcogen (Abbott Murex), Slidex meningite kit 5 (bioMerieux), and Pastorex (Sanofi) kits and beads coated in house with antibodies to Y and to W135 alone were tested. Positive control antigens consisted of A and C polysaccharide preparations and the Pastorex Y/W135 kit sample. The limiting concentrations of antigen detection were determined by USELAT and by LAT. Thirty five clinical samples (plasma), previously characterised by the polymerase chain reaction (PCR) and culture, were tested by USELAT and, when sample volume allowed, by LAT. Results: USELAT enhancement of control antigen detection ranged from 16 to 128 fold for the different latex systems. Enhancements for the different control antigens were comparable between kits. USELAT tests of clinical (A/C/Y/W135) samples (n = 15) with the Wellcogen (A/C/Y/W135) and Slidex meningite (A/C/Y/W135) kits showed comparable specificities. A set (n = 22) of Y and W135 samples gave 18, 19, and 17 positive results for Wellcogen (A/C/Y/W135), Pastorex (A/C/Y/W135), and in house beads (Y/W135), respectively. Positive USELAT PCR and culture results were concordant. A typical sensitivity for the commercial kits was 80% (Wellcogen). Conclusions: USELAT identified serogroups for 80% of samples, whereas LATs identified only 40%. The USELAT detection of the A, C, Y, and W135 antigen serogroups showed comparable enhancement for the kits tested. The commercial availability of latex beads coated with antibody to the Y and W135 serogroups would expedite their identification. PMID:11825922

  16. Tracking polymer diffusion in a wet latex film with fluorescence resonance energy transfer.

    PubMed

    Haley, Jeffrey C; Liu, Yuanqin; Winnik, Mitchell A; Demmer, David; Haslett, Tom; Lau, Willie

    2007-08-01

    We describe an instrument to measure the polymer interdiffusion between donor-labeled and acceptor-labeled latex polymers in a partially wet latex film with fluorescence resonance energy transfer (FRET). It is possible to temporarily arrest the drying process of a wet latex film by sealing the film in an airtight chamber. In our approach, we measure donor fluorescence decays from 0.5 mm diameter spots at various positions across an arrested latex film with time-correlated single photon counting. We interpret the resulting decays with a Monte Carlo simulation of the FRET process and extract information about the extent of polymer diffusion as a function of position on the film. These results enable us to determine the extent of polymer interdiffusion as a function of distance from the wet-dry edge in the latex film. To highlight this device's ability to capture the rapid early stages of latex interdiffusion, we report results from an acrylate copolymer latex.

  17. The Cenozoic Diversity of Agglutinated Foraminifera - Evidence for a late Oligocene to early Miocene diversification event

    NASA Astrophysics Data System (ADS)

    Kaminski, Michael; Setoyama, Eiichi; Kender, Sev; Cetean, Claudia

    2014-05-01

    The agglutinated foraminifera are among the most abundant micro-organisms in the deep marine environment and have a diversity record extending back to the late Precambrian. We present an updated diversity curve for agglutinated foraminiferal genera based on the stratigraphic ranges of all the agglutinated genera recognized as valid in the classification of Kaminski (2014). The data set for this analysis is based on the stratigraphic ranges of agglutinated genera published in Foraminiferal Genera and their Classification, which has been subsequently updated based on published studies and our new observations. The mean standing diversity of agglutinated foraminiferal genera was compiled by counting the number of boundary crossers rather than the number of genera in each stage. In this study, we report the stratigraphic and geographical occurrence of a benthic foraminiferal diversification event that has previously received little attention. In the latest Oligocene to earliest Miocene a number of trochospiral agglutinated genera with alveolar or canaliculate walls first appeared in the fossil record. Our studies of late Oligocene of the Congo fan, offshore Angola (Kender et al., 2008; Cetean and Kaminski, 2011) have revealed a diverse assemblage that includes new taxa of deep-water agglutinated foraminifera. In a biostratigraphic study of the Miocene foraminiferal assemblages Kender et al. (2008) noted steadily increasing diversity and proportions of infaunal agglutinated foraminiferal morphotypes over the lower Miocene interval. The proportion of infaunal agglutinated foraminifera assigned to the order Textularida increased dramatically in the lower mid-Miocene, suggesting expansion of the oxygen minimum zone into deeper waters. In addition to the trochospiral alveolar genera, several species of Reticulophragmium and Cyclammina display rapid diversification into numerous separate lineages that are at present not reflected in our generic diversity record owing to

  18. Simulation of Mechanical Behavior of Agglutinates

    NASA Technical Reports Server (NTRS)

    Nakagawa, Masami; Moon, Tae-Hyun

    2005-01-01

    Due to lack of "real" lunar soil or even lunar simulant, it is difficult to characterize the interaction between lunar soil (or simulant) with different surfaces that are involved in excavation and processing machinery. One unique feature possessed by lunar soil is the agglutinates produced by repeated high-speed micrometeoroid impacts and subsequent pulverization[l and 2]. The large particles are impacted by micrometeoroids [Fig.l] and pulverized to produce finer particles. This process continues until there are no more "large" particles left on the surface of the moon. Due to high impact speed, the impact melting process fuses fines to make agglutinates such as shown in Fig. 2. We will present a series of simulation results and movies will be shown to indicate brittle behavior of each individual agglutinate and also similar compressibility charts shown by Carrier et al. [3]. Fig. 3 shows our preliminary result of the simulated oedometer tests.

  19. Nursing students with latex allergy.

    PubMed

    Katrancha, Elizabeth D; Harshberger, Lorri A

    2012-11-01

    Latex allergy affects millions of people in the general population and a higher percentage of health care workers. Nursing students with a latex sensitivity pose a unique challenge for the nurse educator. Students may enter the program with pre-existing latex allergy or develop the allergy during the educational process. This manuscript explores the implications of latex allergies exhibited by the nursing student. It addresses the responsibilities of the educator in the skills or simulation laboratory and during clinical learning experiences. It also offers suggestions for ensuring the safety of the student while reducing the legal liabilities of the educational program. The article addresses possible policy ramifications for nursing schools.

  20. Stable suspension for Vi-agglutination tests

    PubMed Central

    Ando, Koji; Shimojo, Hiroto

    1953-01-01

    Two methods of preparing a stable suspension for Vi-agglutination tests are discussed. Both maintain Vi-agglutinability and O-inagglutinability after storage at 37°C for 6 months, and the second also maintains the Vi-capsule-staining property. The first method involves the addition of 0.5% CaCl2 to a heavy saline Vi-suspension, while in the second a similar suspension is treated with an 0.2% solution of chrome alum. PMID:20603972

  1. Protein characterisation of Brosimum gaudichaudii Trécul latex and study of nanostructured latex film formation.

    PubMed

    Barbosa, Eduardo F; Monge-Fuentes, Victoria; Oliveira, Natiela B; Tavares, Rebecca; Xavier, Mary-Ann E; Bemquerer, Marcelo Porto; Silva, Luciano P

    2014-12-01

    Brosimum gaudichaudii Tréc. (Moraceae) is a common Brazilian Cerrado plant known by its pharmaceutical industry relevance. The authors investigated the latex protein components and potential biotechnological applications. Some protein fragments had their sequences elucidated, presenting similarities to jacalin and Kunitz-type trypsin inhibitors. Amino acid residue modifications were found, such as glutamine N-terminal residue cyclisation into pyroglutamic acid residue, and mass differences corresponding to hexoses and N-acetylhexosamine presence. The latex was used to produce a nanoscale structured film, which presented an increased attraction and reduced adhesion behaviours. The film presented high homogeneity, as observed by low nanoroughness values, probably because of its intrinsic components, such as the jacalin-like protein that has known agglutination properties. The immobilised Kunitz-type trypsin inhibitor presence in the latex film allow us to point out to applications related to this inhibition, as in active food packaging, since these peptidase inhibitors are able to inhibit pests and microorganism proliferation.

  2. Are the Major Agglutinative Languages Genetically Related?

    ERIC Educational Resources Information Center

    Hakola, H. P. A.

    1989-01-01

    Examination of accidental CVC and CV correspondences among languages representing 5 large families of agglutinative languages found that comparison pairs had much more similarity between basic 100-word vocabularies than would have been possible by mere chance, supporting the hypothesis that those 5 language families were mutually related.…

  3. Process to create simulated lunar agglutinate particles

    NASA Technical Reports Server (NTRS)

    Gustafson, Robert J. (Inventor); Gustafson, Marty A. (Inventor); White, Brant C. (Inventor)

    2011-01-01

    A method of creating simulated agglutinate particles by applying a heat source sufficient to partially melt a raw material is provided. The raw material is preferably any lunar soil simulant, crushed mineral, mixture of crushed minerals, or similar material, and the heat source creates localized heating of the raw material.

  4. Rapid presumptive identification of Cryptococcus neoformans.

    PubMed Central

    Muchmore, H G; Felton, F G; Scott, E N

    1978-01-01

    Carbohydrate-containing extracts were prepared from mature yeast colonies grown on Sabouraud dextrose agar by mixing a 0.001-ml loopful of yeast cells for 30 s in phenolized saline and removing the cells by centrifugation. Extracts were prepared from 54 Cryptococcus neoformans isolates, 29 isolates of other Cryptococcus species, 16 isolates of Candida species, 2 Rhodotorula, 2 Torulopsis, and 1 Saccharomyces species. Initially the carbohydrate content of each extract was estimated (Molisch method) and adjusted to 1, 5, and 10 microgram/ml. Twofold dilutions of each extract were tested for reactivity with the cryptococcal latex agglutination reagent of Bloomfield et al. (N. Bloomfield, M.A. Gordon, and D.F. Elmendorf, Jr., Proc. Soc. Exp. Biol. Med. 114:64-67, 1963). All 54 C. neoformans extracts gave strong agglutinations (3+ to 4+) in dilutions of 1:4 or greater. None of the other yeasts produced any agglutination, except for 1 of 15 C. laurentii isolates, which showed a 1+ reaction that disappeared at a dilution of 1:4 and above. Subsequent testing established that a single extract made from 0.001 ml of yeast cells in 6 ml of phenolized saline contained less than 5 microgram of carbohydrate per ml, was suitable for a single rapid screening dilution, and eliminated any cross-reaction from the C. laurentii isolates. In our hands this method has provided a reliable differentiation of C. neoformans from other unknown yeast colonies in less than 20 min exclusive of a Molisch determination. PMID:359587

  5. The Rapid Diagnosis of Leptospirosis: A Prospective Comparison of the Dot Enzyme-Linked Immunosorbent Assay and the Genus-Specific Microscopic Agglutination Test at Different Stages of Illness

    DTIC Science & Technology

    1988-04-01

    reference laboratories. Sim- ting" I liL of leptospiral antigen (770 ng of protein, Lowry pler techniques have been described, but information is...detect recent albumin for 1 min with shaking on a plane rotator. After exposure to leptospires ; it is also rapid and simpler to use aspiration of...by the isola, battery of 24 pathogenic serovars. Tenl, to 14.d-old cul- tion of leptospires fromt bloodi or urine. Only serologicil ture% wete

  6. Single-molecule detection of proteins with antigen-antibody interaction using resistive-pulse sensing of submicron latex particles

    NASA Astrophysics Data System (ADS)

    Takakura, T.; Yanagi, I.; Goto, Y.; Ishige, Y.; Kohara, Y.

    2016-03-01

    We developed a resistive-pulse sensor with a solid-state pore and measured the latex agglutination of submicron particles induced by antigen-antibody interaction for single-molecule detection of proteins. We fabricated the pore based on numerical simulation to clearly distinguish between monomer and dimer latex particles. By measuring single dimers agglutinated in the single-molecule regime, we detected single human alpha-fetoprotein molecules. Adjusting the initial particle concentration improves the limit of detection (LOD) to 95 fmol/l. We established a theoretical model of the LOD by combining the reaction kinetics and the counting statistics to explain the effect of initial particle concentration on the LOD. The theoretical model shows how to improve the LOD quantitatively. The single-molecule detection studied here indicates the feasibility of implementing a highly sensitive immunoassay by a simple measurement method using resistive-pulse sensing.

  7. [Latex allergy--Part I].

    PubMed

    Chełmińska, Marta

    2004-01-01

    Natural rubber latex (NRL), is a resin sap produced in the cells of caoutchouc plants. It is a water dispersion of cis-1,4-polisopren (caoutchouc)--35%, stabilized with little amounts of proteins, sugar, alcohol, fatty acids and salts. The concentration of all solid substances is about 40%, the rest is water. Immunogenicity of latex depends on the proteins it contains. For many years we read in medical papers about the cases of contact urticaria, asthma, rhinitis, and anaphylaxis after contacting with latex products. It turns out that medical staff is the group of high occupational risk, because of exposure to gloves and other latex products. It is connected with the fact of high gloves usage caused by the danger of virus infections: HIV, HBV, HCV. Latex allergy is one of the reasons of dramatic complications after surgical operations. People who are allergic to latex may have cross reactions to allergens not connected with occupational environment. These are: food and houseplants (Ficus benjamina). The frequency of latex allergy is about 0.1% of the population. In the groups of high risk the frequency rises sharply. It is 17% among medical staff and it reaches 60% among children with spina bifida.

  8. Development of a slide agglutination assay for detection of blastomycosis.

    PubMed

    Hatch, Wayne O; Scalarone, Gene M

    2013-11-01

    Blastomycosis, caused by the thermally dimorphic fungus Blastomyces dermatitides, which is endemic to eastern regions of the USA, is commonly misdiagnosed as a viral or bacterial infection and therefore treated improperly. Over the years, many immunodiagnostic assays to aid in the diagnosis of blastomycosis have been developed; however, a reliable assay for use in local clinics still remains elusive. Procedures for a slide agglutination assay for detection of antibody in serum from rabbits immunized with B. dermatitidis were evaluated with antigenic preparations from B. dermatitidis adsorbed to polystyrene microparticles. Yeast-phase lysates from five isolates of B. dermatitides: namely ER-593 (Eagle River, WI, USA), ER-598 (Eagle River, WI, USA), 48938 (India), B5896 (Mt. Iron, MN, USA), and T-58 (TN, USA) were evaluated for their sensitivity and specificity. Sensitivities of the lysates ranged from 29% to 83% whereas specificities ranged from 13% to 100%. Lysate ER-593 provided the most promising results with a sensitivity of 82% and specificity of 100%. This study provides suggests that a simple rapid slide agglutination assay for detecting blastomycosis may be used for screening patients with suspected B. dermatitidis infection.

  9. 40 CFR 428.100 - Applicability; description of the latex-dipped, latex-extruded, and latex-molded rubber subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... latex-dipped, latex-extruded, and latex-molded rubber subcategory. 428.100 Section 428.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex-Dipped, Latex-Extruded, and Latex-Molded Rubber Subcategory §...

  10. 40 CFR 428.100 - Applicability; description of the latex-dipped, latex-extruded, and latex-molded rubber subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... latex-dipped, latex-extruded, and latex-molded rubber subcategory. 428.100 Section 428.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex-Dipped, Latex-Extruded, and Latex-Molded Rubber Subcategory §...

  11. 40 CFR 428.100 - Applicability; description of the latex-dipped, latex-extruded, and latex-molded rubber subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... latex-dipped, latex-extruded, and latex-molded rubber subcategory. 428.100 Section 428.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex-Dipped, Latex-Extruded, and Latex-Molded Rubber Subcategory §...

  12. 40 CFR 428.100 - Applicability; description of the latex-dipped, latex-extruded, and latex-molded rubber subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... latex-dipped, latex-extruded, and latex-molded rubber subcategory. 428.100 Section 428.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex-Dipped, Latex-Extruded, and Latex-Molded Rubber Subcategory §...

  13. 40 CFR 428.100 - Applicability; description of the latex-dipped, latex-extruded, and latex-molded rubber subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... latex-dipped, latex-extruded, and latex-molded rubber subcategory. 428.100 Section 428.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex-Dipped, Latex-Extruded, and Latex-Molded Rubber Subcategory §...

  14. Latex allergy: a nursing update.

    PubMed

    Kramper, M A

    2000-01-01

    Latex allergy emerged in the 1990's as a significant and challenging public health concern for patients as well as healthcare workers. This article provides a review of this complex health care challenge. Understanding latex allergy production and sources of exposure will provide a background to explore the immunological implications of this exposure risk. Diagnostic and treatment measures are reviewed. The focus of this article is to increase awareness and encourage prevention of this growing health concern.

  15. Making Latex Microspheres in Space

    NASA Technical Reports Server (NTRS)

    Kornfeld, D. M.; Vanderhoff, J. W.; El-Aasser, M. S.; Micale, F. J.; Sudol, E. D.; Tseng, C. M.; Silwanowicz, A.

    1986-01-01

    Equipment yields larger, more uniform particles. Two NASA reports describe first commercial product to be manufactured in space. Product monodisperse latex, suspension of spherical particles of essentially same diameter. Carried aboard Space Shuttle on its orbital missions, monodisperse latex reactor (MLR) produces spheres of much larger size than possible on Earth. Mircospheres 30 micrometers in diameter produced, whereas 5 micrometers is limit for Earthbound reactors. Microspheres as large as 100 micrometers scheduled for production in MLR.

  16. Investigating the rheological properties of native plant latex

    PubMed Central

    Bauer, Georg; Friedrich, Christian; Gillig, Carina; Vollrath, Fritz; Speck, Thomas; Holland, Chris

    2014-01-01

    Plant latex, the source of natural rubber, has been of interest to mankind for millennia, with much of the research on its rheological (flow) properties focused towards industrial application. However, little is known regarding the rheology of the native material as produced by the plant, a key factor in determining latex's biological functions. In this study, we outline a method for rheological comparison between native latices that requires a minimum of preparatory steps. Our approach provides quantitative insights into the coagulation mechanisms of Euphorbia and Ficus latex allowing interpretation within a comparative evolutionary framework. Our findings reveal that in laboratory conditions both latices behave like non-Newtonian materials with the coagulation of Euphorbia latex being mediated by a slow evaporative process (more than 60 min), whereas Ficus appears to use additional biochemical components to increase the rate of coagulation (more than 30 min). Based on these results, we propose two different primary defensive roles for latex in these plants: the delivery of anti-herbivory compounds (Euphorbia) and rapid wound healing (Ficus). PMID:24173604

  17. Investigating the rheological properties of native plant latex.

    PubMed

    Bauer, Georg; Friedrich, Christian; Gillig, Carina; Vollrath, Fritz; Speck, Thomas; Holland, Chris

    2014-01-06

    Plant latex, the source of natural rubber, has been of interest to mankind for millennia, with much of the research on its rheological (flow) properties focused towards industrial application. However, little is known regarding the rheology of the native material as produced by the plant, a key factor in determining latex's biological functions. In this study, we outline a method for rheological comparison between native latices that requires a minimum of preparatory steps. Our approach provides quantitative insights into the coagulation mechanisms of Euphorbia and Ficus latex allowing interpretation within a comparative evolutionary framework. Our findings reveal that in laboratory conditions both latices behave like non-Newtonian materials with the coagulation of Euphorbia latex being mediated by a slow evaporative process (more than 60 min), whereas Ficus appears to use additional biochemical components to increase the rate of coagulation (more than 30 min). Based on these results, we propose two different primary defensive roles for latex in these plants: the delivery of anti-herbivory compounds (Euphorbia) and rapid wound healing (Ficus).

  18. Modeling of pervaporation with latex membranes

    SciTech Connect

    Huang, R.Y.M.; Wei, Y. )

    1994-06-01

    Latex membranes have shown potential to be a new type of pervaporation separation membrane. Three types of latex membranes were prepared in our laboratory by direct casting of polymer latexes. These latex membranes were selective toward water during pervaporation with ethanol-water mixtures. The free-volume approach was employed to characterize the pervaporation of these latex membranes. It is shown by this experiment that the Yeom-Huang model, which is based on the free-volume theory and the thermodynamics, can be used to model the pervaporation process of the latex membranes which give reasonable predictions on the permeability. 18 refs., 3 figs., 8 tabs.

  19. D-penicillamine prevents ram sperm agglutination by reducing the disulphide bonds of a copper-binding sperm protein.

    PubMed

    Leahy, T; Rickard, J P; Aitken, R J; de Graaf, S P

    2016-05-01

    Head-to-head agglutination of ram spermatozoa is induced by dilution in the Tyrode's capacitation medium with albumin, lactate and pyruvate (TALP) and ameliorated by the addition of the thiol d-penicillamine (PEN). To better understand the association and disassociation of ram spermatozoa, we investigated the mechanism of action of PEN in perturbing sperm agglutination. PEN acts as a chelator of heavy metals, an antioxidant and a reducing agent. Chelation is not the main mechanism of action, as the broad-spectrum chelator ethylenediaminetetraacetic acid and the copper-specific chelator bathocuproinedisulfonic acid were inferior anti-agglutination agents compared with PEN. Oxidative stress is also an unlikely mechanism of sperm association, as PEN was significantly more effective in ameliorating agglutination than the antioxidants superoxide dismutase, ascorbic acid, α-tocopherol and catalase. Only the reducing agents cysteine and DL-dithiothreitol displayed similar levels of non-agglutinated spermatozoa at 0 h compared with PEN but were less effective after 3 h of incubation (37 °C). The addition of 10 µM Cu(2+) to 250 µM PEN + TALP caused a rapid reversion of the motile sperm population from a non-agglutinated state to an agglutinated state. Other heavy metals (cobalt, iron, manganese and zinc) did not provoke such a strong response. Together, these results indicate that PEN prevents sperm association by the reduction of disulphide bonds on a sperm membrane protein that binds copper. ADAM proteins are possible candidates, as targeted inhibition of the metalloproteinase domain significantly increased the percentage of motile, non-agglutinated spermatozoa (52.0% ± 7.8) compared with TALP alone (10.6% ± 6.1).

  20. The chemistry of some individual lunar soil agglutinates

    NASA Technical Reports Server (NTRS)

    Gibbons, R. V.; Hoerz, F.; Schaal, R. B.

    1976-01-01

    The inquiry is centered on the composition of agglutinate glasses examined via microprobe techniques. The glass chemistry of the agglutinates is brought into relation with compositions of constituent detritus and bulk compositions of the parent soils, with recent reported results taken into cognizance. Electron microprobe analysis data were examined for possible chemical fractionation resulting from meteoritic impacts and formation of agglutinates in the lunar regolith; individual agglutinates from lunar soils 78222, 71061, and 60009 were probed. Differences between impact glasses and corresponding bulk soils were scrutinized. Agglutinate glass analyses tend to cluster near the bulk soil compositions. A slight enrichment in mafic elements in grand averages of the agglutinate clusters relative to the bulk soils was found. Evidence of total impact melts and minor partial shock melts is examined.

  1. Mass-based readout for agglutination assays

    NASA Astrophysics Data System (ADS)

    Chunara, Rumi; Godin, Michel; Knudsen, Scott M.; Manalis, Scott R.

    2007-11-01

    We present a mass-based readout for agglutination assays. The suspended microchannel resonator (SMR) is used to classify monomers and dimers that are formed during early stage aggregation, and to relate the total count to the analyte concentration. Using a model system of streptavidin functionalized microspheres and biotinylated antibody as the analyte, we obtain a dose-response curve over a concentration range of 0.63-630nM and show that the results are comparable to what has been previously achieved by image analysis and conventional flow cytometry.

  2. The latex story.

    PubMed

    Raulf, Monika

    2014-01-01

    The milky sap of the rubber tree Hevea brasiliensis is the source of the commercial production of natural rubber latex (NRL) devices, and also represents a source of potent allergenic proteins. NRL materials were introduced in the health care field in about 1840 with the advent of technical abilities to produce suitable and flexible NRL materials for medical products, especially gloves. In the late 1980s, with the increase of transmittable diseases, particularly HIV infection, the use of NRL gloves increased dramatically. During the 1990s, NRL emerged as a major cause of clinically relevant allergy in health care workers using NRL gloves and spina bifida patients with operation on the first day. The increased recognition of NRL allergies, the enhanced research on allergen characterization and sensitization mechanisms, and education about this allergy in health care facilities combined with the introduction of powder-free gloves with reduced protein levels are all factors associated with a decline in the number of suspected cases of NRL allergies in the late 1990s. NRL allergy is a very good example of a 'new allergy' that suddenly arises with tremendous health and economic implications, and also of an allergy which becomes history in a relatively short period of time based on successful primary prevention strategies by strict allergen avoidance.

  3. Penicillamine prevents ram sperm agglutination in media that support capacitation.

    PubMed

    Leahy, T; Rickard, J P; Aitken, R J; de Graaf, S P

    2016-02-01

    Ram spermatozoa are difficult to capacitate in vitro. Here we describe a further complication, the unreported phenomenon of head-to-head agglutination of ram spermatozoa following dilution in the capacitation medium Tyrodes plus albumin, lactate and pyruvate (TALP). Sperm agglutination is immediate, specific and persistent and is not associated with a loss of motility. Agglutination impedes in vitro sperm handling and analysis. So the objectives of this study were to investigate the cause of sperm agglutination and potential agents which may reduce agglutination. The percentage of non-agglutinated, motile spermatozoa increased when bicarbonate was omitted from complete TALP suggesting that bicarbonate ions stimulate the agglutination process. d-penicillamine (PEN), a nucleophilic thiol, was highly effective at reducing agglutination. The inclusion of 250 μM PEN in TALP reduced the incidence of motile, agglutinated spermatozoa from 76.7 ± 2.7% to 2.8 ± 1.4%. It was then assessed if PEN (1 mM) could be included in existing ram sperm capacitation protocols (TALP +1 mM dibutyryl cAMP, caffeine and theophylline) to produce spermatozoa that were simultaneously capacitated and non-agglutinated. This protocol resulted in a sperm population which displayed high levels of tyrosine phosphorylated proteins and lipid disordered membranes (merocyanine-540) while remaining motile, viable, acrosome-intact and non-agglutinated. In summary, PEN (1 mM) can be included in ram sperm capacitation protocols to reduce sperm agglutination and allow for the in vitro assessment of ram sperm capacitation.

  4. Direct agglutination test for serologic diagnosis of Neospora caninum infection.

    PubMed

    Romand, S; Thulliez, P; Dubey, J P

    1998-01-01

    A direct agglutination test was evaluated for the detection and quantitation of IgG antibodies to Neospora caninum in both experimental and natural infections in various animal species. As compared with results obtained by the indirect fluorescent antibody test, the direct agglutination test appeared reliable for the serologic diagnosis of neosporosis in a variety of animal species. The direct agglutination test should provide easily available and inexpensive tools for serologic testing for antibodies to N. caninum in many host species.

  5. Nitrogen isotopic signatures in agglutinates from breccia 79035

    NASA Technical Reports Server (NTRS)

    Kerridge, John F.; Kim, Yoosook; Kim, Jin S.; Marti, Kurt

    1993-01-01

    Agglutinates in the size range 125-175 microns from regolith breccia 79035 are substantially depleted in N compared with bulk 79035. Isotopically, agglutinate N closely resembles that found previously in ilmenite separates. The minimum (delta)N-15 value found during stepwise pyrolysis of agglutinates is significantly heavier than that observed for bulk 79035. The major host phase for trapped N in 79035, and the host phase of the lightest isotopic component(s), remain unidentified.

  6. EVALUATION OF LOW-VOC LATEX PAINTS

    EPA Science Inventory

    The paper gives results of an evaluation of four commercially available low-VOC (volatile organic compound) latex paints as substitutes for conventional latex paints by assessing both their emission characteristics and their performance as coatings. Bulk analysis indicated that ...

  7. Function of fibrinogen gamma-chain dodecapeptide-conjugated latex beads under flow.

    PubMed

    Takeoka, Shinji; Okamura, Yosuke; Teramura, Yuji; Watanabe, Naohide; Suzuki, Hidenori; Tsuchida, Eishun; Handa, Makoto; Ikeda, Yasuo

    2003-12-19

    In order to perform a fundamental study of platelet substitutes, novel particles that bound to activated platelets were prepared using two oligopeptides conjugated to latex beads. The oligopeptides were CHHLGGAKQAGDV (H12), which is a fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411), and CGGRGDF (RGD), which contains a fibrinogen alpha-chain sequence (alpha 95-98 RGDF). Both peptides contained an additional amino-terminal cysteine to enable conjugation. Human serum albumin was adsorbed onto the surface of latex beads (average diameter 1microm) and pyridyldisulfide groups were chemically introduced into the adsorbed protein. H12 or RGD peptides were then chemically linked to the modified surface protein via disulfide linkages. H12- or RGD-conjugated latex beads prepared in this way enhanced the in vitro thrombus formation of activated platelets on collagen-immobilized plates under flowing thrombocytopenic-imitation blood. Based on the result of flow cytometric analyses of agglutination, PAC-1 binding, antiP-selectin antibody binding, and annexin V binding, the H12-conjugated latex beads showed minimal interaction with non-activated platelets. These results indicate the excellent potential of H12-conjugated particles as a candidate for a platelet substitute.

  8. Latex allergy in women's health care.

    PubMed

    Fletcher, Joanne

    2013-01-01

    Latex allergy in midwifery and women's health care is not a new concept, with numerous case reports documenting adverse reactions in pregnant women to natural rubber latex in the birthing room. The practising midwife, nurse and sonographer need to be aware of the signs and symptoms of latex allergy and the implications of a severe reaction to latex not only to the woman but also the unborn child.

  9. Systems, devices, and methods for agglutination assays using sedimentation

    DOEpatents

    Schaff, Ulrich Y.; Sommer, Gregory J.; Singh, Anup K.

    2016-01-26

    Embodiments of the present invention include methods for conducting agglutination assays using sedimentation. Aggregates may be exposed to sedimentation forces and travel through a density medium to a detection area. Microfluidic devices, such as microfluidic disks, are described for conducting the agglutination assays, as are systems for conducting the assays.

  10. Integration of latex protein sequence data provides comprehensive functional overview of latex proteins.

    PubMed

    Cho, Won Kyong; Jo, Yeonhwa; Chu, Hyosub; Park, Sang-Ho; Kim, Kook-Hyung

    2014-03-01

    The laticiferous system is one of the most important conduit systems in higher plants, which produces a milky-like sap known as latex. Latex contains diverse secondary metabolites with various ecological functions. To obtain a comprehensive overview of the latex proteome, we integrated available latex proteins sequences and constructed a comprehensive dataset composed of 1,208 non-redundant latex proteins from 20 various latex-bearing plants. The results of functional analyses revealed that latex proteins are involved in various biological processes, including transcription, translation, protein degradation and the plant response to environmental stimuli. The results of the comparative analysis showed that the functions of the latex proteins are similar to those of phloem, suggesting the functional conservation of plant vascular proteins. The presence of latex proteins in mitochondria and plastids suggests the production of diverse secondary metabolites. Furthermore, using a BLAST search, we identified 854 homologous latex proteins in eight plant species, including three latex-bearing plants, such as papaya, caster bean and cassava, suggesting that latex proteins were newly evolved in vascular plants. Taken together, this study is the largest and most comprehensive in silico analysis of the latex proteome. The results obtained here provide useful resources and information for characterizing the evolution of the latex proteome.

  11. Detection of Salmonella enterica serovar Enteritidis (SE) Antibodies in Serum Using A Polystyrene Bead/SE Flagella Agglutination Assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serologic screening of flocks can be an important method to detect Salmonella enteritidis (SE) infections but can be labor intensive or lack specificity. Our goal was to develop a rapid agglutination assay using SE flagella adsorbed to polystyrene beads as a simple, relatively specific test to dete...

  12. Latex allergies and adverse reactions: a review of the literature.

    PubMed

    Weesner, B W

    1997-04-01

    In the last few years, the allergenic potential of latex has been receiving greater attention. While latex allergies have been widely reported in the literature, the prevalence and severity have rapidly increased in the last few years. The role of rubber in the prevention of HIV infection has played a part in recognizing the allergenic potential, as with increased emphasis on infection control in the dental office has come an increase in complaints of adverse reactions to surgical gloves. A review of the literature reveals latex allergy problems to be not confined to gloves, but to articles of clothing, rubber dam material, and other latex-containing materials. Life-threatening cases have been reported. Little information in the literature concerns the extent of the problem among dental personnel. The dental professional may be faced with not only discomfort for the dental staff, but also compromising reactive possibilities in certain patients. There is a need for development of alternative protective products for the dental office, since elimination of barrier protection is not a viable alternative to infection control.

  13. Effect of field natural rubber latex with different ammonia contents and storage period on physical properties of latex concentrate, stability of skim latex and dipped film

    NASA Astrophysics Data System (ADS)

    Santipanusopon, Sirinapa; Riyajan, Sa-Ad

    2009-07-01

    The effect of ammonia treatment in field natural rubber (NR) latex with different storage period time on the properties of concentrated NR latex and stability of skim latex was investigated. Fresh NR latex was treated with various ammonia contents such as 0.35, 0.60 and 0.80% w/w, and then they were centrifuged to get the concentrated NR latex with 60% dry rubber content (DRC) containing 0.16, 0.18 and 0.25% w/w, respectively and skim NR latex with roughly 5% DRC containing 0.42, 0.60 and 0.80% w/w, respectively. The effect of storage times with ∼0, 15, 30 and 45 days for concentrated NR latex with different ammonia contents on their properties such as alkalinity, magnesium content and viscosity was observed. It was found that generally, magnesium content in field NR latex and latex concentrate decreased with storage period times. The alkalinity content in both concentrated NR and skim latex increased with increasing ammonia content in field latex. The viscosity of concentrated NR latex increased as a function of storage period time of field NR latex. The stability of skim latex depends on storage period time of field NR latex with different ammonias. The tensile strength of dipped films obtained from field NR latex with 0.80% w/w of ammonia was dependent on storage period time of field NR latex.

  14. Allergenic proteins of natural rubber latex.

    PubMed

    Yeang, H Y; Arif, Siti Arija M; Yusof, Faridah; Sunderasan, E

    2002-05-01

    As the living cytoplasm of laticiferous cells, Hevea brasiliensis latex is a rich blend of organic substances that include a mélange of proteins. A small number of these proteins have given rise to the problem of latex allergy. The salient characteristics of H. brasiliensis latex allergens that are recognized by the International Union of Immunological Societies (IUIS) are reviewed. These are the proteins associated with the rubber particles, the cytosolic C-serum proteins and the B-serum proteins that originate mainly from the lutoids. Procedures for the isolation and purification of latex allergens are discussed, from latex collection in the field to various preparative approaches adopted in the laboratory. As interest in recombinant latex allergens increases, there is a need to validate recombinant proteins to ascertain equivalence with their native counterparts when used in immunological studies, diagnostics, and immunotherapy.

  15. Microgravity and the Formation of Latex Spheres

    NASA Technical Reports Server (NTRS)

    1982-01-01

    This set of photographs illustrates the value of microgravity in the formation of latex spheres. The image at left shows irregular spheres produced on Earth, while the photograph at right shows uniform spheres produced during the STS-3 mission, March 22 - 30, 1982, in the Monodisperse Latex Reactor, developed by the Marshall Space Flight Center and Lehigh University. The Marshall-managed MLR experiment demonstrated the feasibility of producing monodisperse polystyrene latex microspheres in space and their application to medicine and industry.

  16. Producing Large-Particle Monodisperse Latexes

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.

    1986-01-01

    Chemical process produces latex particles of relatively large, uniform size for use as size standards for instrument calibration. Process, based on seeding of mixture by very small latex particles, yields particles measuring 2 to 30 micrometer or more in average size. Produces monodisperse latexes in which deviation from average size is less than 2 percent. Particles used directly, without tedious separation procedures for removing off-size particles.

  17. Rotary Reactor Makes Large Latex Particles

    NASA Technical Reports Server (NTRS)

    Kornfeld, Dale M.

    1988-01-01

    Machine reduces gravitational effects interfering with particle growth. Reaction chamber rotates while polymerization of latex proceeds. Motor turns stirrer. Chamber made of stainless steel with glass windows.

  18. Wetting and spreading of individual latex particles

    SciTech Connect

    Unertl, W.N.; Luo, Y.; Woodland, D.; Bediwi, A.B.E.; Kamal, M.; El Farrash, A.E.

    1996-12-31

    The wetting and spreading of individual latex particles is an important factor in controlling the mechanical properties of coatings such as those used on paper. The interactions between latex particles that lead to coalescence and film formation has been extensively studied and the basic mechanisms have been identified. Surface aspects of the coalescence and film formation for bulk films and dense monolayers have also been studied including the effects of surfactants. However, in many practical applications, including most paper coatings, latex is present in concentrations that are too small for latex-latex interactions to be important. In these applications, the wetting, spreading, and adhesion of individual latex particles on surfaces of the other constituents of the coating are most important. In spite of its importance, this topic has received little attention. This paper describes measurements of the contact angle {theta} and determination of the work of adhesion W of styrene-butadiene latex particles on calcite, mica, cellophane, and polystyrene surfaces. The effects of humidity and latex glass transition temperature on the wetting and spreading are also described. Some implications for the strength of coatings containing low levels of latex binders are also discussed.

  19. Effect of irradiation on the prevulcanized latex/low nitrosamines latex blends

    SciTech Connect

    Ibrahim, Pairu; Zin, Wan Manshol Wan; Daik, Rusli

    2015-09-25

    Radiation Prevulcanized Natural Rubber Latex (RVNRL) was blended with Low Nitrosamines Latex (LNL) at different composition ratio. Methyl Metachrylate (MMA) was added for grafting onto the blended latex. Blended latex was subjected to gamma irradiation at various doses up to 8kGy. The mechanical properties and FTIR analysis were investigated as a function of the blended composition and irradiation dose. It was found that blending at specific ratio and gamma irradiation at specific dose led to significant improvement on the properties of the latex. The optimum mechanical properties was attained at a total blending ratio of 70% RVNRL and 30% of LNL.

  20. Effect of irradiation on the prevulcanized latex/low nitrosamines latex blends

    NASA Astrophysics Data System (ADS)

    Ibrahim, Pairu; Daik, Rusli; Zin, Wan Manshol Wan

    2015-09-01

    Radiation Prevulcanized Natural Rubber Latex (RVNRL) was blended with Low Nitrosamines Latex (LNL) at different composition ratio. Methyl Metachrylate (MMA) was added for grafting onto the blended latex. Blended latex was subjected to gamma irradiation at various doses up to 8kGy. The mechanical properties and FTIR analysis were investigated as a function of the blended composition and irradiation dose. It was found that blending at specific ratio and gamma irradiation at specific dose led to significant improvement on the properties of the latex. The optimum mechanical properties was attained at a total blending ratio of 70% RVNRL and 30% of LNL.

  1. Evaluation of the micro-CATT, CATT/Trypanosoma brucei gambiense, and LATEX/T b gambiense methods for serodiagnosis and surveillance of human African trypanosomiasis in West and Central Africa.

    PubMed Central

    Truc, Philippe; Lejon, Veerle; Magnus, Eddy; Jamonneau, Vincent; Nangouma, Auguste; Verloo, Didier; Penchenier, Laurent; Büscher, Philippe

    2002-01-01

    OBJECTIVE: To evaluate the performance of serological tests using dried blood on filter-papers (micro-card agglutination test for trypanosomiasis (micro-CATT)) performed under field and laboratory conditions and using whole blood ((CATT/T.b. gambiense) (wb-CATT) and latex agglutination (LATEX/T.b. gambiense) (wb-LATEX)) for the serodiagnosis and surveillance of human African trypanosomiasis in West and Central Africa. METHODS: We evaluated the micro-CATT, wb-CATT and wb-LATEX methods in Côte d'Ivoire and the Central African Republic by screening 940 people. Sensitivity and specificity were calculated for each serological test; only patients with the confirmed presence of trypanosomes in the blood or lymph aspirate were considered true positives. Positive and negative predictive values were also calculated. FINDINGS: Each of the tests showed a lower sensitivity in the Central African Republic than in Côte d'Ivoire. CONCLUSION: The results confirmed the efficiency of the classic wb-CATT to detect sleeping sickness patients. The micro-CATT method can be used for human African trypanosomiasis surveillance if the test is performed on the same day as the blood collection, or if samples are stored at 4 degrees C. Otherwise, micro-CATT can be used when absolute sensitivity is not required. wb-LATEX should only be used for high-specificity screening. PMID:12481210

  2. [The diagnostic evaluation of rapid sputum technics for Pneumococcus in community-acquired pneumonia. The usefulness of Bayes theorem for clinical application].

    PubMed

    Menéndez Villanueva, R

    1995-01-01

    This study aimed to quantify the diagnostic value of immunological techniques and methods for rapid analysis of sputum for pneumococcus, using sensitivity and specificity values reported in the literature to calculate positive and negative predictive values (PPV and NPV) according to Bayes formulas. Diagnostic gains of the test are calculated and compared to pretext probability. We located articles reporting sensitivity and specificity of counterimmunoelectrophoresis (CIE), coagglutination (CoA) and latex agglutination (LA) tests. We also calculated the probability ratios for the three tests. LA achieved the best overall diagnostic utility rating. CoA had the highest PPV, whereas LA offered the highest NPV. CIE was the least useful. These three tests are more useful at intermediate levels of prevalence of pneumococcus, which coincide with estimate in our population. We conclude that LA and CoA are of greater diagnostic utility for community acquired pneumonia, as they are useful for determining prevalence as well as for deciding initial antibiotic treatment.

  3. RADIATION INDUCED VULCANIZATION OF RUBBER LATEX

    DOEpatents

    Mesrobian, R.B.; Ballantine, D.S.; Metz, D.J.

    1964-04-28

    A method of vulcanizing rubber latex by exposing a mixture containing rubber latex and from about 15 to about 21.3 wt% of 2,5-dichlorostyrene to about 1.1 megarads of gamma radiation while maintaining the temperature of the mixture at a temperature ranging between from about 56 to about 59 deg C is described. (AEC)

  4. Enhancement of polyisoprene latex production

    NASA Technical Reports Server (NTRS)

    Bauman, Albert J. (Inventor)

    1979-01-01

    Production of high molecular weight polyisoprene latex is enhanced by administering to plants, particularly Guayule Plants, an amine containing at least one two-carbon chain substituent and preferably substituted trialkylamine of the general structure: ##STR1## where R.sub.4, R.sub.5 and R.sub.6 are alkyl, preferably ethyl and at least one of R.sub.4, R.sub.5 and R.sub.6 is preferably an electron withdrawing group substituted aryloxy or arylthio ethyl group.

  5. Nitrile versus Latex for Glove Juice Sampling.

    PubMed

    Landers, Timothy F; Dent, Anthony

    2014-01-01

    The objective of this study was to explore the utility of nitrile gloves as a replacement for latex surgical gloves in recovering bacteria from the hands. Two types of nitrile gloves were compared to latex gloves using the parallel streak method. Streaks of Klebsiella pneumoniae and Staphylococcus aureus were made on tryptic soy agar plates, and the zones of inhibition were measured around pieces of glove material placed on the plates. Latex gloves produced a mean zone of inhibition of 0.28 mm, compared to 0.002 mm for nitrile gloves (p<.001). While the parallel streak method is not intended as a quantitative estimate of antimicrobial properties, these results suggest that nitrile may be a viable alternative to latex in glove juice sampling methods, since nitrile avoids the risk of latex exposure.

  6. Latex improvement of recycled asphalt pavement

    NASA Astrophysics Data System (ADS)

    Drennon, C.

    1982-08-01

    The performance of a single unmodified milled recycled asphalt concrete was compared to milled asphalt concrete modified by addition of three types of rubber latex. Latex was added at 2, 3, 5, and 8 percent latex by weight of asphalt in the asphalt concrete. Lattices used were a styrene butadiene (SBR), a natural rubber (NR), an acrylonitrile butadiene (NBR), and four varieties of out of specification SBR lattices. Marshall tests, while indecisive, showed a modest improvement in properties of SBR and NR added material at 3 and 5 percent latex. Addition of NBR latex caused deterioration in Marshall stability and flow over that of control. Repeated load tests were run using the indirect tensile test, analyzed by the VESYS program, which computes life of pavements. Repeated load tests showed improvement in asphalt concrete life when 3 and 5 percent SBR was added. Improvement was also shown by the out of specification SBR.

  7. Jackfruit anaphylaxis in a latex allergic patient.

    PubMed

    Wongrakpanich, Supakanya; Klaewsongkram, Jettanong; Chantaphakul, Hiroshi; Ruxrungtham, Kiat

    2015-03-01

    Several fruits have been reported to crossreact with latex antigen in latex allergy patients but little is known regarding tropical fruits in particular. Here we report the case of a 34-year old nurse who developed anaphylaxis following the ingestion of dried jackfruit (Artocarpus heterophyllus). The patient had a history of chronic eczema on both hands resulting from a regular wear of latex gloves. She and her family also had a history of atopy (allergic rhinitis and/or atopic dermatitis). The results of skin prick tests were positive for jackfruit, latex glove, kiwi and papaya, but the test was negative for banana. While we are reporting the first case of jackfruit anaphylaxis, further research needs to be conducted to identify the mechanisms underlying it. In particular, in-vitro studies need to be designed to understand if the anaphylaxis we describe is due to a cross reactivity between latex and jackfruit or a coincidence of allergy to these 2 antigens.

  8. Adhesion of latex films. Influence of surfactants

    SciTech Connect

    Charmeau, J.Y.; Kientz, E.; Holl, Y.

    1996-12-31

    In the applications of film forming latexes in paint, paper, coating, adhesive, textile industries, one of the most important property of latex films is adhesion onto a support. From the point of view of adhesion, latex films have two specificities. The first one arises from the particular structure of the film which is usually not homogeneous but retains to a certain extent the memory of the particles it was made from. These structure effects are clearly apparent when one compares mechanical or adhesion properties of pure latex films and of films of the same polymers but prepared from a solution. Latex films show higher Young`s moduli and lower adhesion properties than solution films. The second specificity of latex films comes from the presence of the surfactant which was used in the synthesis and as stabilizer for the latex. Most industrial latexes contain low amounts of surfactant, typically in the range 0.1 to 2-3 wt%. However, being usually incompatible with the polymer, the surfactant is not homogeneously distributed in the film. It tends to segregate towards the film-air or film-support interfaces or to form domains in the bulk of the film. Distribution of surfactants in latex films has been studied by several authors. The influence of the surfactant on adhesion, as well as on other properties, is thus potentially very important. This article presents the results of the authors investigation of surfactant effects on adhesion properties of latex films. To the authors knowledge, there is no other example, in the open literature, of this kind of study.

  9. Mannanoligosaccharide agglutination by Salmonella enterica strains isolated from carrier pigs

    PubMed Central

    Borowsky, Luciane; Corção, Gertrudes; Cardoso, Marisa

    2009-01-01

    Type-1 fimbriae are associated with most Salmonella enterica serovars and are an essential factor for host colonization. Mannanoligosaccharides (MOS), a prebiotic that is agglutinated by type-1 fimbriae, are proposed for the control of enterobacteria colonization and may be an alternative to Salmonella control in pigs. The aim of this study was to evaluate the capability of porcine Salmonella strains to adhere to MOS in vitro. A total of 108 strains of Salmonella sp. isolated from carrier pigs were evaluated for the amplification of fimA and fimH genes, agglutination of MOS and hemagglutination. In all tested strains, amplicons of expected size were detected for both fimA and fimH gene. In the hemagglutination assays, 31 (28.7%) strains presented mannose–sensitive agglutination of erythrocytes, indicating that the strains were expressing type-1 fimbriae. Considering only strains expressing the type-1 fimbriae, 23 (74.2%) presented a strong agglutination of MOS, 3 (9.6%) a weak reaction and 5 (16.2%) none. The results indicate that Salmonella enterica strains expressing type-1 fimbriae can agglutinate effectively in vitro to MOS. PMID:24031388

  10. Lack of impact of rapid identification of rotavirus-infected patients on nosocomial rotavirus infections.

    PubMed

    Dennehy, P H; Tente, W E; Fisher, D J; Veloudis, B A; Peter, G

    1989-05-01

    The efficacy of rapid identification of rotavirus-infected patients in the control of nosocomial rotavirus infections on an infant and young toddler ward by use of a rotavirus antigen detection test on stool from patients with diarrhea was evaluated by comparing the rate of nosocomial rotavirus infection in children during two separate 5-week periods in the winters of 1984 and 1986. In contrast to 1984 rapid rotavirus antigen testing by latex agglutination of stool from patients with diarrhea was instituted in 1986, in addition to testing for rotavirus by enzyme immunoassay, to determine whether use of rapid antigen testing resulted in an increased incidence of appropriate isolation and a decrease in nosocomial infections. In 1986 rapid identification of rotavirus resulted in an increase in hospitalization of rotavirus-infected patients in single bed rooms from 68% to 100% (P = 0.02, chi square test) but no significant increase in the use of enteric precautions for these patients. The total number of cases of nosocomial rotavirus infection in the two periods did not differ. In both periods 11 cases occurred; the nosocomial infection rate in 1984 was 18.9 cases/1000 days of exposure whereas in 1986 it was 20.2 cases/1000 days. These findings indicate that the use of rapid rotavirus antigen testing of patients with diarrhea is not of appreciable benefit in preventing the nosocomial spread of rotavirus to infants on the ward.

  11. Reinforcement of latex rubber by the incorporation of amphiphilic nanoparticles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Latex rubbers are fabricated from latex suspensions. During the fabrication process, latex particles are bound together while water is removed from the suspension. This report shows the mechanical properties of latex rubbers can be improved by incorporating a small amount of amphiphilic nanoparticle...

  12. Evaluation of low-VOC latex paints

    SciTech Connect

    Chang, J.C.S.; Fortmann, R.C.; Roache, N.F.; Lao, H.C.

    1999-01-01

    The paper gives results of an evaluation of four commercially available low-VOC (volatile organic compound) latex paints as substitutes for conventional latex paints by assessing both their emission characteristics and their performance as coatings. Bulk analysis indicated that the VOC contents of all four paints are considerably lower than those of conventional latex paints. Low-VOC emissions were confirmed by small chamber emission tests. However, sigificant emissions of several aldehydes, especially formaldehyde, were detected from two of the paints. ASTM methods were used to evaluate the hiding power, scrubbability, washability, dry to touch, and yellowing index. The results indicated that one of the low-VOC paints tested showed performance equivalent or superior to that of a widely used conventional latex paint used as a control. It was concluded that low-VOC latex paint can be a viable option to replace conventional latex paints for prevention of indoor air pollution. However, paints marketed as low-VOC may still have significant emissions of some individual VOCs, and some may not have performance characteristics matching those of conventional latex paints.

  13. Evaluation of low-VOC latex paints

    SciTech Connect

    Chang, J.C.S.; Fortmann, R.C.; Roache, N.F.; Lao, H.C.

    1999-11-01

    The paper gives results of an evaluation of four commercially available low-VOC (volatile organic compound) latex paints as substitutes for conventional latex paints by assessing both their emission characteristics and their performance as coatings. Bulk analysis indicated that the VOC contents of all four paints are considerably lower than those of conventional latex paints. Low-VOC emissions were confirmed by small chamber emission tests. However, sigificant emissions of several aldehydes, especially formaldehyde, were detected from two of the paints. ASTM methods were used to evaluate the hiding power, scrubbability, washability, dry to touch, and yellowing index. The results indicated that one of the low-VOC paints tested showed performance equivalent or superior to that of a widely used conventional latex paint used as a control. It was concluded that low-VOC latex paint can be a viable option to replace conventional latex paints for prevention of indoor air pollution. However, paints marketed as low-VOC may still have significant emissions of some individual VOCs, and some may not have performance characteristics matching those of conventional latex paints.

  14. Evolution of Shock Melt Compositions in Lunar Agglutinates

    NASA Technical Reports Server (NTRS)

    Vance, A. M.; Christoffersen, R.; Keller, L. P.

    2015-01-01

    Lunar agglutinates are aggregates of regolith grains fused together in a glassy matrix of shock melt produced during smaller-scale (mostly micrometeorite) impacts. Agglutinate formation is a key space weathering process under which the optically-active component of nanophase metallic Fe (npFe(sup 0)) is added to the lunar regolith. Here we have used energy-dispersive X-ray (EDX) compositional spectrum imaging in the SEM to quantify the chemical homogeneity of agglutinitic glass, correlate its homogeneity to its parent soil maturity, and identify the principle chemical components contributing to the shock melt compositional variations.

  15. RED2TEX: A TRIX RED to LATEX converter

    SciTech Connect

    Chase, L.; Langdon, A.B.

    1987-05-20

    A summary of RED2TEX is presented. RED2TEX converts standard TRIX RED format commands to TEX or LATEX commands for subsequent LATEX formatting. LATEX is a special version of the TEX document preparation system. LATEX adds to TEX a collection of commands that simplifies formatting. LATEX runs on the J-Vax and the LLL-LCC Pyramid machines. RED2TEX resides in Unix directory CHASE/TEX.

  16. Cytotoxicity of latex and non-latex orthodontic elastomeric ligatures on L929 mouse fibroblasts.

    PubMed

    Santos, Rogério Lacerda dos; Pithon, Matheus Melo; Martins, Fernanda Otaviano; Romanos, Maria Teresa Villela; Ruellas, Antônio Carlos de Oliveira

    2010-01-01

    This study investigated the cytotoxicity exists between latex and non-latex Orthodontic elastomeric ligatures. Six elastomeric ligatures (1 latex, 2 latex-free and 3 polyurethane) from different manufacturers were divided into 6 groups of 15 elastics each: A (Latex-free, American Orthodontics), M (Polyurethane, Morelli), G (Polyurethane,GAC International), Te (Polyurethane, Tecnident), TP (Natural latex,TP Orthodontics) and U (Latex-free,3M Unitek). The cytotoxicity assay was performed using cell cultures (L929 mouse fibroblast cell line), which were subjected to the cell viability test with neutral red ("dye-uptake") at 1, 2, 3, 7 and 28 days. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). No statistically significant differences (p>0.05) were observed between Groups M and Te in all experimental periods, except at 2 days. No significant differences (p>0.05) in cell viability were found either among Groups A, G, TP and U or between Groups M and Te at 24 h or among Groups CC, A, G, TP and U at 2 and 28 days. It may be concluded that latex-free elastomeric ligatures from American Orthodontics and Unitek trademarks induced less cell lysis compared to latex and polyurethane ligatures.

  17. [The pretransfusion bedside agglutination test is not a "Gold Standard"].

    PubMed

    Levy, G

    2008-11-01

    ABO-incompatible transfusions remain frequent in Europe despite the technological progresses in relation with the potential number of human errors during the control procedures of the transfusion chain. The agglutination bedside-test is only one step of this chain and the amelioration of the security will be achieved by its replacement by an electronical check.

  18. Synthesis for Lunar Simulants: Glass, Agglutinate, Plagioclase, Breccia

    NASA Technical Reports Server (NTRS)

    Weinstein, Michael; Wilson, Stephen A.; Rickman, Douglas L.; Stoeser, Douglas

    2012-01-01

    The video describes a process for making glass for lunar regolith simulants that was developed from a patented glass-producing technology. Glass composition can be matched to simulant design and specification. Production of glass, pseudo agglutinates, plagioclase, and breccias is demonstrated. The system is capable of producing hundreds of kilograms of high quality glass and simulants per day.

  19. [Latex ligation in treatment of chronic hemorrhoids].

    PubMed

    Ektov, V N; Somov, K A

    2015-01-01

    We analyzed the results of treatment of 432 patients with chronic hemorrhoids using different variants of latex ligation. New technique including ligation of mucosa and submucosa of low-ampullar rectum providing ligation of hemorrhoidalvessels, lifting and recto-anal repair is developed and suggested. This method is advisable to use in case of chronic internal hemorrhoids stages I and II. The authors recommend simultaneous combined ligation of mucosa of low-ampullar rectum and internal hemorrhoids for stages III and IV. Different variants of latex ligation with external hemorrhoids excision were used in 103 patients. Pointed variants of latex ligation preserve important advantages including mini-invasiveness, simplicity and wide availability, low cost. Good remote results were obtained after these procedures in 87.3% of observations. Suggested tactics extends use of latex ligation and increases its effectiveness in treatment of different stages and forms of chronic hemorrhoids.

  20. [Prevalence of latex hypersensitivity among medical personnel].

    PubMed

    Camacho Ibarra, V C; López García, A I; Galindo García, J A; Paz Martínez, D; Papaqui Tapia, J S

    1997-01-01

    In order to determine the latex hypersensitivity prevalence in medical residents from Hospital Universitario de Puebla, it was carried out a transversal, observational and descriptive study including the medical staff of all specialties. The epicutancous test was effectuated with 1:20 latex antigen dilution. It was studied a total of 90 medical residents, 68.9% were males and 31.1% females. The mean age was 30.6 years (SD 3.8). The 50% were from clinical specialties and 50% else were from surgical. The global latex hypersensitivity prevalence was 8%. It will be convenient to carry out a follow up of studied cohort to establish if continual exposition, years later, will determine skin reactivity to latex in professional practice.

  1. In vitro study of force decay of latex and non-latex orthodontic elastics.

    PubMed

    López, Noelia; Vicente, Ascensión; Bravo, Luis A; Calvo, José L; Canteras, Manuel

    2012-04-01

    The aim of this study was to evaluate the force decay of two brands of orthodontic elastics, both offering latex and non-latex products. Samples were subjected to continuous stretching, measuring force at 5 seconds, 8 hours, and 24 hours in both dry and wet conditions. Five hundred samples were used, GAC® and Lancer® 0.25 inch and 4 oz, divided into testing sample sizes of n = 25 per group. For the dry test, elastics were kept stretched to three times their internal diameter for 5 seconds (initial force), 8 hours, and 24 hours; for the wet test, they were stretched for 8 and 24 hours. Both brands showed initial forces significantly greater than those specified by the manufacturers (P < 0.05). Comparing wet/dry conditions, there was a greater force loss in the wet medium than the dry. As for elastic composition (latex or non-latex), the only significant difference found was between Lancer elastics with and without latex in dry conditions, force loss being greater for latex-free elastics. Comparing brands, there was greater force loss with GAC than with Lancer. Comparing elastic force at the eight-hour mark and the twenty-four hour mark to the initial force (only in wet conditions), GAC latex and non-latex and Lancer latex elastics showed significantly less force at eight and twenty four hours than initially. On the other hand, Lancer non-latex was the only type of elastics that did not show a significant decrease in its initial elastic characteristics at eight hours in wet conditions. Nevertheless, Lancer non-latex did show significantly less force in wet conditions at twenty four-hours than the forces observed initially and at eight-hours.

  2. Rheology of latex-modified grouts

    SciTech Connect

    Allan, M.L.

    1997-12-01

    The pumpability and ability of cementitious grouts to penetrate voids and cracks is strongly dependent on the rheological behavior of the grout. This is important in diverse grouting applications including ground treatment, repair of concrete, reduction of rock or soil permeability, environmental remediation, prestressing concrete, rock anchors, sealing radioactive waste repositories, and well completion. The rheology of grouts containing latex was investigated. The two latex additives used were carboxylated styrene-butadiene and acrylic. The influences of superplasticizer, fly ash, and blast furnace slag on the rheology of latex-modified grouts were addressed. Shear stress-shear rate curves were determined for a variety of mix proportions. The time-dependent behavior of selected grouts was also studied. It was determined that the yield stress and apparent viscosity are influenced by latex content and that the grouts are shear thinning at low water/cement ratios. Latex imparts stability and thixotropy in grouts. Partial replacement of cement with either fly ash or slag diminishes the effect of latex on rheology.

  3. Agglutinates as recorders of regolith evolution - Application to the Apollo 17 drill core

    SciTech Connect

    Laul, J.C.; Smith, M.R.

    1984-11-15

    Chemical data are reported for agglutinates from 26 depth intervals of the Apollo 17 deep drill core, and the compositions of the agglutinates are compared with those of the soils in which they occur. The agglutinate sequence suggests a scenario in which several closely-spaced depositional events were involved in the formation of the drill core, rather than a continuous accumulation process.

  4. The effects of latex additions on centrifugally cast concrete for internal pipeline protection

    SciTech Connect

    Buchheit, R.G.; Hinkebein, T.E.; Hlava, P.F.; Melton, D.G.

    1993-07-01

    Centrifugally-cast concrete liners applied to the interiors of plain steel pipe sections were tested for corrosion performance in brine solutions. An American Petroleum Institute (API) standard concrete, with and without additions of a styrene-butadiene copolymer latex, was subjected to simulated service and laboratory tests. Simulated service tests used a mechanically pumped test manifold containing sections of concrete-lined pipe. Linear polarization probes embedded at steel-concrete interfaces tracked corrosion rates of these samples as a function of exposure time. Laboratory tests used electrochemical impedance spectroscopy to study corrosion occurring at the steel-concrete interfaces. Electron probe microanalysis (EPMA) determined ingress and distribution of damaging species, such as Cl, in concrete liners periodically returned from the field. Observations of concrete-liner fabrication indicate that latex loading levels were difficult to control in the centrifugal-casting process. Overall, test results indicate that latex additions do not impart significant improvements to the performance of centrifugally cast liners and may even be detrimental. Corrosion at steel-concrete interfaces appears to be localized and the area fraction of corroding interfaces can be greater in latex-modified concretes than in API baseline material. EPMA shows higher interfacial Cl concentration in the latex-modified concretes than in the API standard due to rapid brine transport through cracks to the steel surface.

  5. Characterization of copolymer latexes by capillary electrophoresis.

    PubMed

    Anik, Nadia; Airiau, Marc; Labeau, Marie-Pierre; Bzducha, Wojciech; Cottet, Hervé

    2010-02-02

    Latexes are widely used for industrial applications, including decorative paints, binders for the papermaking industry, and drilling fluids for oil-field applications. In this work, the interest of capillary zone electrophoresis (CE) for the characterization of hydrophobic block copolymer latexes obtained by the conventional emulsion polymerization technique consisting of a core of polystyrene (PS) surrounded by a layer of poly(ethyl acrylate) (PEA) has been investigated. The PEA part of the copolymer can be partially hydrolyzed in poly(acrylic acid) (PAA) leading to PS-PEA-AA water-soluble amphiphilic copolymer having high viscosifying properties. The main purpose of this work was to evaluate the potential of CE for the characterization of the latexes at the different stages of the synthesis (PS core, PS-PEA diblock latex, and hydrolyzed PS-PEA-AA gel). The main analytical issues were to state (i) if there was free PS or PEA homopolymer latexes in the PS-PEA latex sample and (ii) if there was free PS, PEA, PS-PEA latexes, or free PAA chains in the PS-PEA-AA gel. Within this scope, this work describes the optimization of the selectivity of the separation between the different species (PS, PEA particles in the not hydrolyzed diblock latex and PS, PEA, PS-PEA particles as well as the polymer PAA chains in the PS-PEA-AA diblock gel sample obtained by latter latex hydrolysis). For that purpose, several experimental parameters were investigated such as pH and ionic strength of the background electrolyte (BGE) or the concentration of neutral surfactant added in the BGE. A challenging issue was to overcome the high viscosity of the PS-PEA-AA gel. This was resolved by the addition of 10 mM neutral surfactant in the gel sample and in the BGE. Finally, it is demonstrated that, within the detection limits, CE is a suitable analytical tool for controlling and monitoring the syntheses of these latexes and for intrinsically characterizing the distribution in charge density of

  6. Ethanol induces human red cell shape transformations and enhanced ligand-mediated agglutinability

    SciTech Connect

    Weinstein, R.S.; McLawhon, R.W.; Marikovsky, Y.

    1986-03-01

    Ethanol concentrations are markedly elevated in rat stomach wall when ulcerogenic doses of 100 % ethanol (2 ml for 5 to 10 minutes) are instilled in rat gastric lumen. The authors observed that red cells in gastric mucosal postcapillary venules become spiculated and interadherent under these conditions. The authors have now studied this phenomenon in vitro using washing human red cells. Concentrations of high grade ethanol ranging from 2 to 10% (v/v) in physiological buffered saline (pH 7.3) without Ca/sup + +/ or Mg/sup + +/ at 25/sup 0/C rapidly transformed human red cells into spiculated forms. 2% ethanol transformed human red cells into disco-echinocytes in 15 min. whereas 10% ethanol transformed red blood cells into echinocytes within 3 min. Washing out of ethanol at 1 hour reverted the echinocytes into discocytes. However, following 3 hours of incubation in 10% ethanol washing out of ethanol produced stomatocytes. The ethanol-induced echinocytic shape transformations were accompanied by a dose-related increase in red cell agglutinability with poly-L-lysine or the plant lectin wheat germ agglutinin. The enhanced agglutinability was reversed by restoring the red cell shape changes and alterations in surface properties may play a role in the pathogenesis of ethanol-induced gastric ulcers.

  7. Is latex surface charge an important parameter for foam stabilization?

    PubMed

    Kettlewell, Sarah L; Schmid, Andreas; Fujii, Syuji; Dupin, Damien; Armes, Steven P

    2007-11-06

    We describe the facile production of highly stable foams stabilized solely by cationic polystyrene latex particles. Three model polystyrene latexes were synthesized using either a cationic 2,2'-azobis(2-diisobutyramidine) dihydrochloride (AIBA) or an anionic ammonium persulfate (APS) radical initiator: a 724 +/- 81 nm charge-stabilized cationic polystyrene latex [AIBA-PS], an 800 +/- 138 nm sterically stabilized cationic latex prepared using a poly(ethylene glycol) monomethacrylate macromonomer [PEGMA-AIBA-PS], and a 904 +/- 131 nm charge-stabilized anionic polystyrene latex [APS-PS], respectively. The effect of particle surface charge, latex concentration, and solution pH on foam stability was studied in detail. The PEGMA-AIBA-PS latex proved to be the best foam stabilizer even at relatively low latex concentrations (3.0 wt %), with long-term foam stabilities being obtained after drying. The AIBA-PS latex also produced stable foams, albeit only at higher latex concentrations. However, the APS-PS latex proved to be an ineffective foam stabilizer. This is believed to be primarily due to the anionic surface character of this latter latex, which prevents its adsorption at the anionic air-water interface. This hypothesis is supported by the observation that the AIBA-PS latex no longer acts as an effective foam stabilizer above its isoelectric point (pH 7.04). Scanning electron microscopy studies revealed the formation of well-defined latex bilayers within dried foams, which indicates that the wet air bubbles are stabilized by latex monolayers prior to drying. However, little or no long-range ordering of the latex particles was observed on the surface of the bubbles, which is presumably related to the latex polydispersity.

  8. Aqueous particulate foams stabilized solely with polymer latex particles.

    PubMed

    Fujii, S; Iddon, P D; Ryan, A J; Armes, S P

    2006-08-29

    In this article, a wide range of latexes are evaluated as possible foam stabilizers. These include near-monodisperse, poly(N-vinyl pyrrolidone)-stabilized polystyrene [PNVP-PS] latexes with diameters ranging from 170 nm to 1.62 microm, submicrometer-sized poly(ethylene glycol)-stabilized polystyrene [PEGMA-PS] latex particles, a PNVP-stabilized poly(4-bromostyrene) [PNVP-PBrS] latex with a mean diameter of 870 nm, two PNVP-stabilized poly(methyl methacrylate) [PNVP-PMMA] latexes with mean diameters of 730 nm and 1.20 microm, a PNVP-stabilized poly(2-hydroxypropyl methacrylate) [PNVP-PHPMA] latex with a mean diameter of 630 nm, and a charge-stabilized anionic PS latex of 220 nm diameter. The effect of varying the particle size, latex concentration, and latex surface composition on foam stability were studied in detail. The larger PNVP-PS latexes, the PNVP-PBrS, and the two PNVP-PMMA latexes gave highly stable foams, whereas PEGMA-PS, PNVP-PHPMA, and the charge-stabilized PS latex produced either no foams or foams with inferior long-term stabilities. Scanning electron microscopy studies revealed hexagonally close-packed latex arrays in the walls of the dried foam, which leads to localized moiré patterns being observed by optical microscopy. Moreover, these dried foams are highly iridescent in bright transmitted light.

  9. INACTIVATION OF SEXUAL AGGLUTINATION IN HANSENULA WINGEI AND SACCHAROMYCES KLUYVERI BY DISULFIDE-CLEAVING AGENTS.

    PubMed

    TAYLOR, N W

    1964-10-01

    Taylor, Neil W. (Northern Regional Research Laboratory, Peoria, Ill.). Inactivation of sexual agglutination in Hansenula wingei and Saccharomyces kluyveri by disulfide-cleaving agents. J. Bacteriol. 88:929-936. 1964.-Mating types of both Hansenula wingei and Saccharomyces kluyveri can be activated to produce uniformly strong sexual agglutination by treatments with various solvents, such as 8 m LiBr. The strongly agglutinative mating-type preparations were irreversibly inactivated for sexual agglutination by various chemical treatments. Type 5 of H. wingei was inactivated by disulfide-cleaving reagents, but type 21 of H. wingei was not. Type 3 of S. kluyveri was more sensitive than type 26 of S. kluyveri to inactivation by disulfide-cleaving reagents. Comparison of sensitivities to these and other treatments, plus a moderately strong cross-agglutination between type 3 and type 21, indicated that the sexually agglutinative elements on type 3 are similar to type 5, and those of type 21 are similar to those of type 26. Inactivation-rate experiments showed a loss of agglutinative ability according to a sigmoid decrement with time for both types 5 and 21. The apparent extent of inactivation depended markedly on agglutination test conditions. Results of these experiments were interpreted to indicate tentatively, first, that the agglutinative elements of both types of a species are proteins and, second, that several agglutinating linkages are formed between any two cells in sexual agglutination.

  10. The Morphology of Emulsion Polymerized Latex Particles

    DOE R&D Accomplishments Database

    Wignall, G. D.; Ramakrishnan, V. R.; Linne, M. A.; Klein, A.; Sperling, L. H.; Wai, M. P.; Gelman, R. A.; Fatica, M. G.; Hoerl, R. H.; Fisher, L. W.

    1987-11-01

    Under monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structure as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10{sup 4} 10{sup 6} the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M < 10{sup 6} g/mol SANS gave zero angle scattering intensities much higher than expected on the basis of a random distribution of labeled molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights.

  11. Investigation of natural latex rubber gloves

    SciTech Connect

    Vessel, E.M.

    1993-03-19

    Seventy five percent of natural latex rubber gloves used in laboratories at the Savannah River Site are not reused. A cost analysis performed by the SRS Procurement Department determined that a net savings of $1,092,210 could be achieved annually by recycling latex rubber gloves. The Materials Technology Section, at the request of the Procurement Department, examined some mechanical and chemical properties of latex rubber gloves manufactured by Ansell Edmont, which had been purchased by the site specifications for protective clothing. It also examined mechanical properties of re-cycled gloves purchased by specifications and of {open_quotes}off the shelf{close_quotes} gloves manufactured by North Brothers Company. Finally, water vapor transmission studies, simulating tritium permeation, were performed on gloves from both manufacturers. These studies were performed to determine whether latex rubber gloves can be recycled or whether using only new, unwashed gloves is required in areas where tritium exposure is a possibility. The results of these studies indicate that the acceptable glove characteristics, required in the WSRC Manual 5Q1.11, Protective Clothing Specifications, are not adversely affected after washing and drying the gloves manufactured by Ansell Edmont for seven cycles. Results also indicate that natural latex rubber gloves manufactured by North Brothers comply with most of the acceptable glove characteristics specified in the WSRC Manual 5Q1.11. Statistical analysis of the water vapor permeation data show that there is no correlation between permeation rates and the manufacturer.

  12. The morphology of emulsion polymerized latex particles

    SciTech Connect

    Wignall, G.D.; Ramakrishnan, V.R.; Linne, M.A.; Klein, A.; Sperling, L.H.; Wai, M.P.; Gelman, R.A.; Fatica, M.G.; Hoerl, R.H.; Fisher, L.W.

    1987-11-01

    Under monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structre as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10/sup 4/ < M < 6 x 10/sup 6/ g/mol. For M > 10/sup 6/ the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M < 10/sup 6/ g/mol SANS gave zero angle scattering intensities much higher than expected on the basis of a random distribution of labeled molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights. 25 refs., 6 figs., 3 tabs.

  13. Home Healthcare Workers: How to Prevent Latex Allergies

    MedlinePlus

    ... can help prevent allergic reactions for both home healthcare workers and their clients. LATEX EXPOSURE REACTIONS Three ... being used). • Inform your employer and your personal healthcare professionals that you have latex allergy. • Wear a ...

  14. Protein and allergen content of various natural latex articles.

    PubMed

    Baur, X; Chen, Z; Raulf-Heimsoth, M; Degens, P

    1997-06-01

    Proteins remaining in products made of natural rubber latex are potential sensitizers. In the present work, we quantified the releasable protein and allergen contents in 37 brands of latex gloves and 26 other latex products. Our results demonstrate the presence of widely varied protein and allergen contents in various latex articles and the lack of a correlation between the protein and allergen values. These findings may assist hospital management and medical staff to take effective preventive measures.

  15. [Anaphylactic manifestations during protected sexual intercourse disclosing allergy to latex].

    PubMed

    Espin, M; Didier, A; Perez, T; Carre, P; Leophonte, P

    1991-01-01

    Reports of allergy to latex have been increasingly frequent during the last few years. The culprit is the natural Hevea Brasiliensis latex which is present in numerous latex-containing materials for daily use. Clinical manifestations are usually benign. Systemic manifestations have been reported mainly in general anaesthesia. We report a case of severe anaphylactic manifestations that occurred during a condom-protected sexual intercourse. The responsibility of latex for this accident was demonstrated by skin and biological tests.

  16. LaTeX for Agricultural Extension Professionals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    LaTeX is a free open source document preparation system for professional quality documents and presentation materials. Extension professionals, trying to reach their audience though various forms of printed and online resources, can benefit from the vast potential of LaTeX. Using LaTeX empowers the ...

  17. CHARACTERIZATION AND RECYCLING OF WASTE WATER FROM GUAYULE LATEX EXTRACTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guayule commercialization for latex production to be used in medical products and other applications is now a reality. Currently, waste water following latex extraction is discharged into evaporation ponds. As commercialization reaches full scale, the liquid waste stream from latex extraction will b...

  18. The first products made in space: Monodisperse latex particles

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; El-Aasser, M. S.; Micale, F. J.; Sudol, E. D.; Tseng, C.-M.; Sheu, H.-R.; Kornfeld, D. M.

    1988-01-01

    The preparation of large particle size 3 to 30 micrometer monodisperse latexes in space confirmed that original rationale unequivocally. The flight polymerizations formed negligible amounts of coagulum as compared to increasing amounts for the ground-based polymerizations. The number of offsize large particles in the flight latexes was smaller than in the ground-based latexes. The particle size distribution broadened and more larger offsize particles were formed when the polymerizations of the partially converted STS-4 latexes were completed on Earth. Polymerization in space also showed other unanticipated advantages. The flight latexes had narrower particle size distributions than the ground-based latexes. The particles of the flight latexes were more perfect spheres than those of the ground-based latexes. The superior uniformity of the flight latexes was confirmed by the National Bureau of Standards acceptance of the 10 micrometer STS-6 latex and the 30 micrometer STS-11 latexes as Standard Reference Materials, the first products made in space for sale on Earth. The polymerization rates in space were the same as those on Earth within experimental error. Further development of the ground-based polymerization recipes gave monodisperse particles as large as 100 micrometer with tolerable levels of coagulum, but their uniformity was significantly poorer than the flight latexes. Careful control of the polymerization parameters gave uniform nonspherical particles: symmetrical and asymmetrical doublets, ellipsoids, egg-shaped, ice cream cone-shaped, and popcorn-shaped particles.

  19. Measurement of RBC agglutination with microscopic cell image analysis in a microchannel chip.

    PubMed

    Cho, Chi Hyun; Kim, Ju Yeon; Nyeck, Agnes E; Lim, Chae Seung; Hur, Dae Sung; Chung, Chanil; Chang, Jun Keun; An, Seong Soo A; Shin, Sehyun

    2014-01-01

    Since Landsteiner's discovery of ABO blood groups, RBC agglutination has been one of the most important immunohematologic techniques for ABO and RhD blood groupings. The conventional RBC agglutination grading system for RhD blood typings relies on macroscopic reading, followed by the assignment of a grade ranging from (-) to (4+) to the degree of red blood cells clumping. However, with the new scoring method introduced in this report, microscopically captured cell images of agglutinated RBCs, placed in a microchannel chip, are used for analysis. Indeed, the cell images' pixel number first allows the differentiation of agglutinated and non-agglutinated red blood cells. Finally, the ratio of agglutinated RBCs per total RBC counts (CRAT) from 90 captured images is then calculated. During the trial, it was observed that the agglutinated group's CRAT was significantly higher (3.77-0.003) than that of the normal control (0). Based on these facts, it was established that the microchannel method was more suitable for the discrimination between agglutinated RBCs and non-agglutinated RhD negative, and thus more reliable for the grading of RBCs agglutination than the conventional method.

  20. [Rapid laboratory detection of antigens of infective agents of infections and technical means for their realization].

    PubMed

    Kal'noĭ, S M

    2003-01-01

    A system of new accelerated and rapid methods for the detection of the antigens of the infective agents of plague, cholera, tularemia and brucellosis were developed on the basis of solid phase immunosuspension tests: the passive hemagglutination (PHA) test and the latex agglutination (LA) test. The immunological and physico-chemical properties of suspensions in the PHA and LA tests made it possible to use extraneous sources of energy (centrifugal acceleration and the electric field) to accelerate these tests. The results of the PHA and LA tests were registered with the use of a densitometer, model Ultrascan 2202, and a tester, model C 34014.2. To apply centrifugal acceleration and the electric field, a laboratory centrifuge and an electrophoretic microchamber were designed. Densitometry was carried out on modified plates and conductometry, with the use of modified electrodes. The time of obtaining the results of the PHA and LA tests was 15-30 minutes with the use of centrifugation and 2-5 minutes in the electric field, which made it possible to regard these tests as rapid.

  1. Latex of immunodiagnosis for detecting the Chagas disease. I. Synthesis of the base carboxylated latex.

    PubMed

    Gonzalez, Verónica D G; Gugliotta, Luis M; Meira, Gregorio R

    2008-02-01

    This article investigates the synthesis of two (monodisperse, carboxylated, and core-shell) latexes, through a batch and a semibatch emulsion copolymerizations of styrene (St) and methacrylic acid (MAA) onto polystyrene latex seeds. A mathematical model of the process was developed that predicts conversion, average particle size, and surface density of carboxyl groups. The model was adjusted to the batch reaction measurements, and then it was used in the design of the semibatch experiment. The semibatch reaction involved an initial homopolymerization of St followed by instantaneous addition of MAA-St-initiator. Compared with the batch reaction results, the semibatch policy more than doubled the surface density of carboxyl groups. The second part of this series describes the development of an immunodiagnosis latex-protein complex for detecting the Chagas disease, by coupling an antigen of Trypanosoma cruzi onto the produced carboxylated latexes.

  2. kxp and kxpl: A busy man's LaTeX

    SciTech Connect

    Kwong, Man Kam.

    1991-03-01

    This report introduces the following programs: kxp: a time-saving LaTeX preprocessor, kxpl: kxp plus latex, kxh: a help facility for kxp and LaTex, ptex: a program for printing a LaTeX document, and pptex: a program for printing parts of a LaTeX document. More detailed descriptions will be given in Part 2: A Reference Manual. The appendix gives instructions on how to use Argonne's Mathematics and Computer Science Division letterhead and intralaboratory memo L{sup A}T{sub E}X styles.

  3. Polymer interdiffusion and mechanical property development during latex film formation

    SciTech Connect

    Fu, Z.; Boczar, E.M.; Kirk, A.B.

    1995-12-31

    The interdiffusion of polymer chains across the latex boundaries during latex film formation has been studied using the fluorescence technique of direct energy transfer (DET) or small-angle neutron scattering technique (SANS) by several groups. The increase in mechanical strength and the interdiffusion depth determined by SANS has been correlated for several polystyrene latex systems during film formation. In this paper, we will present the correlation between the increase in mechanical strength and the interdiffusion depth for a poly (amyl methacrylate) latex system. Volume fractions of mixing (Fm) as a function of annealing time for two poly (amyl methacrylate) latex blend films were measured.

  4. Type I allergies to latex and the aeroallergenic problem.

    PubMed

    Heese, A; Peters, K P; Koch, H U

    1997-01-01

    Between 1989 and 1995, a 12-fold increase in latex allergy was documented amongst our patients. Similar findings have been noted elsewhere. Increase in type I allergies to latex has become an international problem. The issues associated with latex allergy are described, including those posed by the ubiquitous nature of latex in medical equipment, and in commonplace domestic objects. The potential for allergic patients to cross react to a variety of fruits or plants is an added problem for sensitized patients. This paper concludes that the universal introduction of powder-free surgical gloves with low protein content would be a very important measure in the prevention of acquired latex allergy.

  5. Development and investigation of a selective latex flocculant

    SciTech Connect

    Nikitin, I.N.; Preobrazhenskii, B.P.; Tsyrlov, M.Ya.; Plastovets, I.K.; Litmanovich, I.M.; Tikhonova, O.F.

    1982-01-01

    Investigations were made on the use of two synthetic latexes as selective flocculants in the flotation cleaning of coal. The most commonly used latex in the industry contained sodium dibutylnaphthalenesulfonate, which is a biologically ''hard'' emulsifier. It was determined that butadiene-styrene latexes may successfully be used as selective coal sludge flocculants. The most efficient was a latex synthesized using biodegradable emulsifiers--potassium soaps of disproportionated rosin with a small quantity of synthetic fatty acids. Also, it was concluded that the values of the ash level in the flotation concentrate and tailings could be controlled by regulating the latex consumption.

  6. Latex anaphylaxis caused by a Swan-Ganz catheter.

    PubMed

    Sekiya, Kiyoshi; Watai, Kentaro; Taniguchi, Masami; Mitsui, Chihiro; Fukutomi, Yuma; Tanimoto, Hidenori; Kawaura, Noriyuki; Akiyama, Kazuo

    2011-01-01

    A 78-year-old woman visited the division of cardiovascular disease in our hospital. She underwent a cardiac catheter examination, and a Swan-Ganz catheter was inserted. Several minutes later, she developed anaphylactic shock. She had no past history of latex allergy, but did have a banana allergy. Skin prick tests showed a positive reaction to an extract of latex gloves and an extract of the balloon of a Swan-Ganz catheter. Anaphylactic shock caused by the latex balloon of a Swan-Ganz catheter was diagnosed. It is necessary to pay attention to not only latex allergy but also fruit allergies with a cross-reactivity to latex.

  7. Radiation-induced vulcanisation of natural rubber latex in presence of styrene-butadiene rubber latex

    NASA Astrophysics Data System (ADS)

    Chaudhari, C. V.; Bhardwaj, Y. K.; Patil, N. D.; Dubey, K. A.; Kumar, Virendra; Sabharwal, S.

    2005-04-01

    Radiation vulcanisation of natural rubber latex in presence of styrene butadiene rubber latex (SBRL) has been investigated. The cast films were characterised for their swelling properties, tensile strength and thermal stability as a function of radiation dose as well as SBRL content. The gel content, tensile strength and thermal stability of the copolymer films were found to increase with increasing the SBRL content in the feed solution and radiation dose.

  8. Film formation and paper coating with poly ([beta]-hydroxyalkanoate), a biodegradable latex

    SciTech Connect

    Lauzier, C.A.; Monasterios, C.J.; Saracovan, I.; Marchessault, R.H. ); Ramsay, B.A. )

    1993-05-01

    An aqueous latex of a poly ([beta]-hydroxyalkanoate) (PHA) coated on paper imparted water imperviousness without changing mechanical properties. Hot-pressed films biodegraded faster than solvent cast films. The PHA coating on paper degraded totally in activated sludge within 12 days, leaving the cellulose matrix relatively untouched. Blends of PHA latexes with sodium carboxymethl cellulose, polystyrene latex, carboxylated styrenel butadiene latex, natural rubber latex, carboxylated styrenel butadiene latex; natural rubber latex, and starch powders form satisfactory films at room temperature.

  9. Case report of latex aerosolization from a transesophageal echocardiogram machine.

    PubMed

    Muller, Barbara A; Steelman, Victoria J

    2004-01-01

    Aerosolized natural rubber latex proteins produce latex sensitization and can cause acute allergic reactions in susceptible individuals. The objective of this study is to describe measures that should be taken to ensure a latex-safe hospital environment. A case of latex-induced anaphylaxis prompted a survey of air quality in acute care areas of a major tertiary health care center that had eliminated the use of powder-free latex gloves years earlier. Six air samples were collected using pre- and postcalibrated sampling pumps operating at 2.7 L/minute. Samples were collected in duplicate on three-piece 37-mm Teflon filters in open-faced cassettes and tested for latex allergen by inhibition immunoassay. All samples had less than the detection limit > 5 ng/m3 for aerosolized latex except for the echocardiogram suite where the transesophageal echocardiogram machine was located. After thorough cleaning of the suite and echocardiogram machine, subsequent air sampling showed no detectable latex aerosolization particles. Follow-up investigation to discover the source of contamination revealed that the department performing routine maintenance on the echocardiogram equipment used powdered latex gloves obtained outside the hospital. Employees who are latex allergic may experience symptoms even in an environment of powder-free, nonlatex gloves. The site was a contaminated transesophageal echocardiogram machine. Institutional policies should be in place to monitor employee complaints and address allergic reactions to latex.

  10. Latex allergy: a relevant issue in the general pediatric population.

    PubMed

    Lee, M H; Kim, K T

    1998-01-01

    Although latex allergy is a widely recognized problem of the pediatric myelomeningocele population and of frequent users of latex products, it is often overlooked in the general pediatric population. The prevalence of latex in common household items and in medical environments increases one's exposure and thus one's possibility of sensitization to latex. Latex allergy may range from mild local reactions such as erythema to more severe systemic reactions such as asthma or anaphylaxis. The immunoglobulin E-mediated mechanism of these reactions has been confirmed serologically by the presence of latex-specific immunoglobulin E with radioallergosorbent testing. Because avoidance of latex is currently the only way to prevent reactions, the identification of household items that contain latex is extremely important. However, because inadvertent exposure to latex is not uncommon, Medic-Alert bracelets and an Epi-Pen should be provided for children allergic to latex. Pediatric nurses should consider latex allergy as a possible diagnosis in situations of unexplained allergic or anaphylactic reactions and should be aware of optimal therapeutic interventions.

  11. Electrical-conductivity testing of latex gloves

    SciTech Connect

    Stampfer, J.F.; Salazar, J.A.; Trujillo, A.G.; Harris, T.; Berardinelli, S.P.

    1994-11-01

    There is an increasing awareness in the healthcare field that gloves worn for protection from hazards associated with body fluids do not always afford the protection desired. Gloves may have defects, such as holes, as they come from the manufacturer or distributor, or they may become defective during storage or use. While the numbers vary widely, failure rates for new gloves, defined as detectable holes in gloves prior to use, for unused examination gloves are reported as high as 58%. Rates as high as 7% have been reported for sterile latex gloves. Incidences of breaching the latex barrier during use vary with procedure but have been reported as high as 50%. In recent years, a number of devices have been developed to detect holes in latex gloves as they are being worn. Detection of increased electrical conductivity that takes place through the holes in the gloves is used to activate an audible alarm. The primary purpose of this research was to investigate the validity of this method for hole detection. This evaluation was accomplished with both basic laboratory equipment and commercially available instruments. We did not evaluate or critically compare the individual devices. We also investigated the use of electrical conductivity as a quality assurance (QA) procedure, and the degradation of latex gloves due to storage and exposure to laboratory atmospheres and disinfectants.

  12. From polymer latexes to multifunctional liquid marbles.

    PubMed

    Fernandes, Ana M; Mantione, Daniele; Gracia, Raquel; Leiza, Jose R; Paulis, Maria; Mecerreyes, David

    2015-02-25

    A simple method to prepare multifunctional liquid marbles and dry water with magnetic, color, and fluorescent properties is presented. Multifunctional liquid marbles were prepared by encapsulation of water droplets using flocculated polymer latexes. First, the emulsion polymerization reaction of polystyrene and poly(benzyl methacrylate) was carried out using cheap and commercially available cationic surfactants. Subsequently, flocculation of the latex was provoked by an anion-exchange reaction of the cationic surfactant by the addition of lithium bis(trifluoromethanesulfonyl)imide salt. The flocculated polymer latex was filtered and dried, leading to very hydrophobic micronanoparticulated powders. These powders showed a great ability to stabilize the air/water interface. Stable liquid marbles were obtained by rolling water droplets onto the hydrophobic powders previously prepared. The use of very small polystyrene nanoparticles led us to the preparation of very stable and the biggest known liquid marbles up to 2.5 mL of water. Furthermore, the introduction of fluorescent comonomer dyes into the polymer powders allowed us to obtain new morphological images and new knowledge about the structure of liquid marbles by confocal microscopy. Furthermore, the introduction of magnetic nanoparticles into the polymer latex led to magnetic responsive liquid marbles, where the iron oxide nanoparticles are protected within a polymer. Altogether this method represents an accessible and general platform for the preparation of multifunctional liquid marbles and dry water, which may contribute to extending of their actual range of applications.

  13. Selective sorption of latex membranes with ethanol-water mixtures

    SciTech Connect

    Wei, Y.; Huang, R.Y.M. )

    1994-02-01

    Latex membranes have recently found use in pervaporation separation. The sorption of water-ethanol mixtures to latex membranes was carried out on three types of latex membranes, poly(acrylonitrile-co-butyl acrylate) [P(AN-BuA)], poly(methyl methacrylate-co-butyl acrylate) [P(MMA-BuA)], and poly(styrene-co-butyl acrylate) [P(ST-BuA)], which were prepared in our laboratory by direct casting of polymer latexes synthesized by emulsion polymerization. These latex membranes all exhibit preferential sorption and permeation toward water. Both water and ethanol sorption to the latex membranes exhibited nonideal sorption, with water sorption being enhanced greatly by the presence of ethanol. It was shown that the solubility parameter theory did not give correct predictions for the preferential sorption of latex membranes. Better results were obtained by using the Flory-Huggins interaction parameter. 12 refs., 4 figs., 2 tabs.

  14. Serogrouping of Bacteroides fragilis subsp. fragilis by the agglutination test.

    PubMed Central

    Lambe, D W; Moroz, D A

    1976-01-01

    The agglutination technique was used to establish a serological classification scheme for 98 strains of Bacteroides fragilis subsp. fragilis isolated from clinical specimens and normal human feces. Absorbed antisera were prepared to seven strains of B. fragilis subsp. fragilis. These seven absorbed antisera were species as well as subspecies specific and provided the basis of the serological classification scheme. This scheme was composed of 21 serogroups; seven of these serogroups contained only one group component. There was a total of 45 serological patterns. This serological scheme may be used for the serological classification of strains of B. fragilis subsp. fragilis and to study the epidemiology of this organism. PMID:950378

  15. Formation of agglutinate-like particles in an experimental regolith

    NASA Technical Reports Server (NTRS)

    See, Thomas H.; Horz, Friedrich

    1988-01-01

    Agglutinate-like particles composed predominantly of glass were produced from a fragmental gabbro target that was repetitively impacted by Ni-alloy projectiles. The experimental glasses are much more heterogeneous in composition than their lunar counterparts, and they are dominated by incomplete mixing of melted component minerals and by plagioclase-rich compositions. Most of the particles are found to be highly enriched in feldspar and to be sustantially fractionated relative to the initial bulk target. It is suggested that fractionation trends within lunar agglutinitic glasses may be partly due to phase-specific melting.

  16. Triterpenoid biosynthesis in Euphorbia lathyris latex

    SciTech Connect

    Hawkins, D.R.

    1987-11-01

    The structures of triterpenols, not previously been known, from Euphorbia lathyris latex are reported. A method for quantifying very small amounts of these compounds was developed. Concerning the biochemistry of the latex, no exogenous cofactors were required for the biosynthesis and the addition of compounds such as NADPAH and ATP do not stimulate the biosynthesis. The addition of DTE or a similar anti-oxidant was found to help reduce the oxidation of the latex, thus increasing the length of time that the latex remains active. The requirement of a divalent cation and the preference for Mn in the pellet was observed. The effect of several inhibitors on the biosynthesis of the triterpenoids was examined. Mevinolin was found to inhibit the biosynthesis of the triterpenoids from acetate, but not mevalonate. A dixon plot of the inhibition of acetate incorporation showed an I/sub 50/ concentration of 3.2 ..mu..M. Fenpropimorph was found to have little or no effect on the biosynthesis. Tridemorph was found to inhibit the biosynthesis of all of the triterpenoids with an I/sub 50/ of 4 ..mu..M. It was also observed that the cyclopropyl containing triterpenols, cycloartenol and 24-methylenecycloartenol were inhibited much more strongly than those containing an 8-9 double bond, lanosterol and 24-methylenelanosterol. The evidence indicates, but does not definetely prove, that lanosterol and 24-methylenelanosterol are not made from cycloartenol and 24-methylenecycloartenol via a ring-opening enzyme such as cycloeucalenol-obtusifoliol isomerase. The possibilty that cycloartenol is made via lanosterol was investigated by synthesizing 4-R-4-/sup 3/H-mevalonic acid and incubating latex with a mixture of this and /sup 14/C-mevalonic acid. From the /sup 3/H//sup 14/C ratio it was shown that cycloartenol and 24-methylenecycloartenol are not made via an intermediate containing as 8-9 double bond. 88 refs., 15 figs., 30 tabs.

  17. Direct observation of pH-induced coalescence of latex-stabilized bubbles using high-speed video imaging.

    PubMed

    Ata, Seher; Davis, Elizabeth S; Dupin, Damien; Armes, Steven P; Wanless, Erica J

    2010-06-01

    The coalescence of pairs of 2 mm air bubbles grown in a dilute electrolyte solution containing a lightly cross-linked 380 nm diameter PEGMA-stabilized poly(2-vinylpyridine) (P2VP) latex was monitored using a high-speed video camera. The air bubbles were highly stable at pH 10 when coated with this latex, although coalescence could be induced by increasing the bubble volume when in contact. Conversely, coalescence was rapid when the bubbles were equilibrated at pH 2, since the latex undergoes a latex-to-microgel transition and the swollen microgel particles are no longer adsorbed at the air-water interface. Rapid coalescence was also observed for latex-coated bubbles equilibrated at pH 10 and then abruptly adjusted to pH 2. Time-dependent postrupture oscillations in the projected surface area of coalescing P2VP-coated bubble pairs were studied using a high-speed video camera in order to reinvestigate the rapid acid-induced catastrophic foam collapse previously reported [Dupin, D.; et al. J. Mater. Chem. 2008, 18, 545]. At pH 10, the P2VP latex particles adsorbed at the surface of coalescing bubbles reduce the oscillation frequency significantly. This is attributed to a close-packed latex monolayer, which increases the bubble stiffness and hence restricts surface deformation. The swollen P2VP microgel particles that are formed in acid also affected the coalescence dynamics. It was concluded that there was a high concentration of swollen microgel at the air-water interface, which created a localized, viscous surface gel layer that inhibited at least the first period of the surface area oscillation. Close comparison between latex-coated bubbles at pH 10 and those coated with 66 microm spherical glass beads indicated that the former system exhibits more elastic behavior. This was attributed to the compressibility of the latex monolayer on the bubble surface during coalescence. A comparable elastic response was observed for similar sized titania particles, suggesting

  18. Diagnosis of toxoplasmosis in pregnancy. Evaluation of latex-protein complexes by immnunoagglutination.

    PubMed

    Peretti, Leandro E; Gonzalez, Verónica D G; Marcipar, Iván S; Gugliotta, Luis M

    2017-03-14

    The aim of this work was to obtain a reagent based on latex particles for ruling out acute toxoplasmosis in pregnant women by immunoagglutination (IA). Latex-protein complexes (LPC) were previously synthesized coupling the recombinant protein of Toxoplasma gondii P22Ag and the homogenate of the parasite to latex particles with different size, chemical functionality and charge density. LPC were tested in IA assays against a panel of 72 pregnant women serum samples. Results were analysed through receiver operating characteristic curves, determining area under the curve (AUC), sensitivity, specificity positive and negative predictive values (PPV and NPV, respectively). It was observed that the antigenicity of proteins was not affected during sensitization by either physical adsorption or covalent coupling. The best results in the sense of maximizing discrimination of low avidity sera from chronic ones were observed for the IA test based on latex particles with carboxyl functionality and the recombinant P22Ag, obtaining an AUC of 0·94, a sensitivity of 100% and a NPV of 100%. In this way, the proposed test could be useful for the toxoplasmosis diagnosis in pregnant women, with the advantages of being cheap, rapid and easy to be implemented.

  19. Quantitative determination of fibrinogen of patients with coronary heart diseases through piezoelectric agglutination sensor.

    PubMed

    Chen, Qinghai; Hua, Xing; Fu, Weiling; Liu, Dongbo; Chen, Ming; Cai, Guoru

    2010-01-01

    Fibrinogen can transform fibrin through an agglutination reaction, finally forming fibrin polymer with grid structure. The density and viscosity of the reaction system changes drastically during the course of agglutination. In this research, we apply an independently-developed piezoelectric agglutination sensor to detect the fibrinogen agglutination reaction in patients with coronary heart diseases. The terminal judgment method of determining plasma agglutination reaction through piezoelectric agglutination sensor was established. In addition, the standard curve between plasma agglutination time and fibrinogen concentration was established to determinate fibrinogen content quantitatively. The results indicate the close correlation between the STAGO paramagnetic particle method and the method of piezoelectric agglutination sensor for the detection of Fibrinogen. The correlation coefficient was 0.91 (γ = 0.91). The determination can be completed within 10 minutes. The fibrinogen concentration in the coronary heart disease group was significantly higher than that of the healthy control group (P < 0.05). The results reveal that high fibrinogen concentration is closely correlated to the incurrence, development and prognosis of coronary heart diseases. Compared with other traditional methods, the method of piezoelectric agglutination sensor has some merits such as operation convenience, small size, low cost, quick detecting, good precision and the common reacting agents with paramagnetic particle method.

  20. Ultrasensitive Antibody Detection by Agglutination-PCR (ADAP)

    PubMed Central

    2016-01-01

    Antibodies are widely used biomarkers for the diagnosis of many diseases. Assays based on solid-phase immobilization of antigens comprise the majority of clinical platforms for antibody detection, but can be undermined by antigen denaturation and epitope masking. These technological hurdles are especially troublesome in detecting antibodies that bind nonlinear or conformational epitopes, such as anti-insulin antibodies in type 1 diabetes patients and anti-thyroglobulin antibodies associated with thyroid cancers. Radioimmunoassay remains the gold standard for these challenging antibody biomarkers, but the limited multiplexability and reliance on hazardous radioactive reagents have prevented their use outside specialized testing facilities. Here we present an ultrasensitive solution-phase method for detecting antibodies, termed antibody detection by agglutination-PCR (ADAP). Antibodies bind to and agglutinate synthetic antigen–DNA conjugates, enabling ligation of the DNA strands and subsequent quantification by qPCR. ADAP detects zepto- to attomoles of antibodies in 2 μL of sample with a dynamic range spanning 5–6 orders of magnitude. Using ADAP, we detected anti-thyroglobulin autoantibodies from human patient plasma with a 1000-fold increased sensitivity over an FDA-approved radioimmunoassay. Finally, we demonstrate the multiplexability of ADAP by simultaneously detecting multiple antibodies in one experiment. ADAP’s combination of simplicity, sensitivity, broad dynamic range, multiplexability, and use of standard PCR protocols creates new opportunities for the discovery and detection of antibody biomarkers. PMID:27064772

  1. The interaction of antigen and antibody in agglutination

    PubMed Central

    Elek, S. D.; Smith, B. V. Kingsley; Highman, Wilma

    1964-01-01

    Flagellar fragments are thin cylinders that are particularly suitable for the study of agglutination by electron microscopy. Their shape leads to a characteristic pattern of agglutination and thus the early stages can be studied. Measurement of interflagellar distances under conditions of negative staining, suggest that the minimum length of the rabbit antibody molecules is about 180 Å. The molecules carry the specific sites at the ends of the long axis, and become attached radially to the surface of the flagella, resembling the bristles of a bottle-brush. To explain this orientation it is postulated that the antibody is inserted into the surface of the flagellum in such a manner that surrounding molecules give it a fixed direction. Geometrically this hypothesis corresponds to an insertion into pits. Pepsin-treated (5S) rabbit antibody behaves in a like manner, but the molecule appears to be shorter. No information could be obtained about the thickness and actual shape of antibody molecules by the techniques employed. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 9FIG. 11FIG. 13FIG. 14FIG. 15 PMID:14210767

  2. Medical devices manufactured from latex: European regulatory initiatives.

    PubMed

    De Jong, W H; Geertsma, R E; Tinkler, J J B

    2002-05-01

    In Europe the marketing of medical devices manufactured from latex is regulated by directives describing the essential (safety) requirements that products have to fulfill to obtain marketing approval. This paper describes the general requirements for marketing medical devices in Europe and, more specifically, the requirements for products manufactured from natural rubber latex. The requirements for marketing medical devices can be fulfilled by using the relevant harmonized European standards. These standards are regularly under revision to incorporate the latest scientific developments. For certain devices, for example, latex medical (examination and surgical) gloves, specific standards have been published. Medical devices manufactured from latex pose a serious problem because of the risk of induction of allergy both against the latex proteins inherently present (type I or immediate type allergy) and against chemicals added during processing (type IV or delayed type hypersensitivity) present as residues in the latex products. So, besides requirements for product quality in terms of barrier properties, strength, and sterility, the main focus consists of the allergy-inducing properties of the latex products. Recent developments have reopened the discussion on the value of total protein versus allergen determination in latex medical gloves. However, as long as minimal levels needed for both sensitization and elicitation have not been established, a safe maximum level for leachable proteins/allergens in latex products cannot be determined. A European Commission guidance document on the latex allergy problem is currently being drafted by experts from Competent Authorities.

  3. Mercury sensing and toxicity studies of novel latex fabricated silver nanoparticles.

    PubMed

    Borase, Hemant P; Patil, Chandrashekhar D; Salunkhe, Rahul B; Suryawanshi, Rahul K; Salunke, Bipinchandra K; Patil, Satish V

    2014-11-01

    Safe and eco-friendly alternatives to currently used hazardous chemico-physical methods of silver nanoparticles (AgNPs) synthesis are need of time. Rapid, low cost, selective detection of toxic metals in environmental sample is important to take safety action. Toxicity assessment of engineered AgNPs is essential to avoid its side effects on human and non-target organisms. In the present study, biologically active latex from Euphorbia heterophylla (Poinsettia) was utilized for synthesis of AgNPs. AgNPs was of spherical shape and narrow size range (20-50 nm). Occurrence of elemental silver and crystalline nature of AgNPs was analyzed. Role of latex metabolites in reduction and stabilization of AgNPs was analyzed by FT-IR, protein coagulation test and phytochemical analysis. Latex-synthesized AgNPs showed potential in selective and sensitive detection of toxic mercury ions (Hg(2+)) with limit of detection around 100 ppb. Addition of Hg(2+) showed marked deviation in color and surface plasmon resonance spectra of AgNPs. Toxicity studies on aquatic non-target species Daphnia magna showed that latex-synthesized AgNPs (20.66 ± 1.52% immobilization) were comparatively very less toxic than chemically synthesized AgNPs (51.66 ± 1.52% immobilization). Similarly, comparative toxicity study on human red blood cells showed lower hemolysis (4.46 ± 0.01%) by latex-synthesized AgNPs as compared to chemically synthesized AgNPs causing 6.14 ± 0.01% hemolysis.

  4. Proteolytic properties of Funastrum clausum latex.

    PubMed

    Morcelle, Susana R; Caffini, Néstor O; Priolo, Nora

    2004-07-01

    As part of a screening of latex endopeptidases from plants growing in Argentina, the presence of proteolytic activity in the latex of Funastrum clausum stems is reported. The proteases present in the crude extract showed the main characteristics of the cysteine proteolytic class, i.e. optimum pH at alkaline range, isoelectric point (pI) higher than 9.0, and inhibition of proteolytic activity by thiol blocking reagents. A remarkable thermal stability was also evident in the crude extract. Endosterolytic preference tried on p-nitrophenyl esters of N-alpha-carbobenzoxy-L-amino acids was higher for the alanine, asparagine and tyrosine derivatives. Preliminary peptidase purification by two-step ionic exchange showed the presence of two proteolytic fractions with molecular masses of approximately 24.0 kDa according to SDS-PAGE.

  5. Latex migration in battery slurries during drying.

    PubMed

    Lim, Sanghyuk; Ahn, Kyung Hyun; Yamamura, Masato

    2013-07-02

    We used real-time fluorescence microscopy to investigate the migration of latex particles in drying battery slurries. The time evolution of the fluorescence signals revealed that the migration of the latex particles was suppressed above the entanglement concentration of carboxymethyl cellulose (CMC), while it was significantly enhanced when CMC fully covered the surfaces of the graphite particles. In particular, a two-step migration was observed when the graphite particles flocculated by depletion attraction at high CMC/graphite mass ratios. The transient states of the nonadsorbing CMC and graphite particles in a medium were discussed, and the uses of this novel measurement technique to monitor the complex drying processes of films were demonstrated.

  6. Evaluation of simulant migration of volatile nitrosamines from latex gloves and balloons by HS-SPME-GC-MS.

    PubMed

    Feng, Di; Liu, Luo; Zhao, Liyuan; Zhou, Qingfeng; Tan, Tianwei

    2012-09-01

    Nitrosamines are a group of carcinogens that have been found in various latex products. Methods have been developed for extraction, concentration and detection of simulant migration of volatile nitrosamines from latex gloves and balloons. After glove samples or balloon samples were treated with artificial sweat and artificial saliva, headspace solid-phase microextraction and gas chromatography with mass spectrometer detection were performed. Eight volatile nitrosamines were extracted by a fused silica fiber coated with carboxen-polydimethylsioxane, and solid-phase microextraction conditions were optimized. The developed method was successfully used to analyze simulant migration of volatile nitrosamines from latex gloves and balloons. The described methods are rapid and simple, with adequate sensitivity and without organic solvent.

  7. Metabolic changes in Euphorbia palusrtis latex after fungal infection.

    PubMed

    Krstić, Gordana; Anđelković, Boban; Choi, Young Hae; Vajs, Vlatka; Stević, Tatjana; Tešević, Vele; Gođevac, Dejan

    2016-11-01

    The variations of metabolic profile of the latex of wild-growing Euphorbia palustris was carried out using multivariate analysis of (1)H NMR spectral data. One population was infected with fungi Fusarium sporotrichioides, Fusarium proliferatum and Alternaria alternata, while the other consisted of healthy plant species. The non-polar metabolites of latex extracts such as benzoyl ingenol-laurate, amyrin decadienoate esters, cis-1,4-polyisoprene, and 24-methylenecycloartanol were identified using (1)H and 2D NMR spectra. Principal component analysis of (1)H NMR data provided a clear discrimination between the latex of infected and healthy plants. Minimum inhibitory concentration and minimum fungicidal concentration values of the latex extracts of healthy and infected plants were determined. The latex of infected plants was found to contain higher levels of benzoyl ingenol-laurate and 24-methylenecycloartanol, of which concentrations were strongly correlated with the antifungal activities of the latex.

  8. Identification and practical management of latex allergy in occupational settings.

    PubMed

    Caballero, María Luisa; Quirce, Santiago

    2015-01-01

    Allergy to natural rubber latex (NRL) from Hevea brasiliensis is a relevant occupational health hazard. The use of gloves and products manufactured with latex and environmental allergen exposure in the work environment are risks factors for the development of occupational allergy among different job categories. Healthcare workers have been the most commonly affected, but other professions with exposure to latex products such as hairdressers, cleaners, food handlers and those making natural rubber latex (NRL) products are also at risk of developing occupational allergy. Clinical manifestations of IgE-mediated latex allergy can range from troublesome skin disorders to life-threatening systemic reactions. It is very important to identify the occupational allergic diseases in their early stages in order to implement avoidance strategies. For this purpose, the interventions for prevention should emphasize the importance of latex allergy awareness and surveillance among exposed workforces.

  9. Occupational asthma due to latex in health care workers.

    PubMed Central

    Ho, A.; Chan, H.; Tse, K. S.; Chan-Yeung, M.

    1996-01-01

    Immediate hypersensitivity reactions ranging from mild urticaria to life threatening anaphylaxis after exposure to natural rubber latex have been reported frequently in health care workers while occupational asthma due to latex exposure is less well studied. The results of specific challenge tests and immunological tests in four health care workers with work related respiratory and skin disorders induced by the use of latex gloves are described. Occupational asthma was confirmed in three subjects by specific challenge tests. All had a positive skin test reaction to the latex extract; specific IgE antibodies were detected in only one subject. The fourth subject had a negative specific inhalation and skin test reaction to the latex extract. Peak expiratory flow monitoring at work and away from work showed a pattern consistent with work related asthma. These findings confirm that latex is a cause of occupational asthma in health care workers. PMID:8994533

  10. [Detection of pentachlorophenol in natural rubber latex].

    PubMed

    Jaworska, E

    1976-01-01

    The method of detection of pentachlorophenol in natural rubber latex is proposed. Pentachlorophenol is isolated from other nonrubber-like substances by thin-layer chromatography and identified by spectroscopic method in UV-light. Isolation of pentachlorophenol is carried out from water extracts obtained from the dry caoutchouc films, so the same method can be used for examination of the rubber articles designed for the medicinetoo.

  11. A multi-target real-time PCR assay for rapid identification of meningitis-associated microorganisms.

    PubMed

    Favaro, Marco; Savini, Vincenzo; Favalli, Cartesio; Fontana, Carla

    2013-01-01

    A central nervous system (CNS) infection, such as meningitis, is a serious and life-threatening condition. Bacterial meningitis can be severe and may result in brain damage, disability or even death. Rapid diagnosis of CNS infections and identification of the pathogenic microorganisms are needed to improve the patient outcome. Bacterial culture of a patient's cerebrospinal fluid (CSF) is currently considered the "gold standard" for diagnosing bacterial meningitis. From the CSF cultures researchers can assess the in vitro susceptibility of the causative microorganism to determine the best antibiotic treatment. However, many of the culture assays, such as microscopy and the latex agglutination test are not sensitive. To enhance pathogen detection in CSF samples we developed a multi-target real-time PCR assay that can rapidly identify six different microorganisms: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Streptococcus agalactiae, Listeria monocytogenes and Cryptococcus neoformans. In this study we applied this PCR analysis to 296 CSF samples from patients who were suspected of having meningitis. Of the 296 samples that were examined, 59 samples were positive according to the CSF culture and/or molecular assays. Forty-six CSF samples were positive for both the CSF culture and our real-time PCR assay, while 13 samples were positive for the real-time PCR but negative for the traditional assays. This discrepancy may have been caused by the fact that these samples were collected from 23 patients who were treated with antimicrobials before CSF sampling.

  12. A novel flow cytometry-based assay for the quantification of antibody-dependent pneumococcal agglutination

    PubMed Central

    van der Gaast—de Jongh, Christa E.; Diavatopoulos, Dimitri A.; de Jonge, Marien I.

    2017-01-01

    The respiratory pathogen Streptococcus pneumoniae is a major cause of diseases such as otitis media, pneumonia, sepsis and meningitis. The first step towards infection is colonization of the nasopharynx. Recently, it was shown that agglutinating antibodies play an important role in the prevention of mucosal colonization with S. pneumoniae. Here, we present a novel method to quantify antibody-dependent pneumococcal agglutination in a high-throughput manner using flow cytometry. We found that the concentration of agglutinating antibodies against pneumococcal capsule are directly correlated with changes in the size and complexity of bacterial aggregates, as measured by flow cytometry and confirmed by light microscopy. Using the increase in size, we determined the agglutination index. The cutoff value was set by measuring a series of non-agglutinating antibodies. With this method, we show that not only anti-polysaccharide capsule antibodies are able to induce agglutination but that also anti-PspA protein antibodies have agglutinating capabilities. In conclusion, we have described and validated a novel method to quantify pneumococcal agglutination, which can be used to screen sera from murine or human vaccination studies, in a high-throughput manner. PMID:28288168

  13. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false The standard tube agglutination test... Blood Testing Procedures § 147.1 The standard tube agglutination test. 1 1 The procedure described is a... containers provided by the laboratory. The containers should be stout-walled test tubes, preferably 3/8 by...

  14. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false The standard tube agglutination test... Blood Testing Procedures § 147.1 The standard tube agglutination test. 1 1 The procedure described is a... containers provided by the laboratory. The containers should be stout-walled test tubes, preferably 3/8 by...

  15. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false The standard tube agglutination test... Blood Testing Procedures § 147.1 The standard tube agglutination test. 1 1 The procedure described is a... containers provided by the laboratory. The containers should be stout-walled test tubes, preferably 3/8 by...

  16. The role of water in latex coalescence

    SciTech Connect

    Sperry, P.R.; Snyder, B.S.

    1993-12-31

    The role of water in the particle deformation and compaction stage of latex polymer film formation is investigated via Minimum Film Formation Temperature (MFT) measurements as a function of polymer composition, time, and water content in the deposition and drying environments. Water content of the system ranged from very low (latex film predried well below the MFT before imposition of the temperature gradient, with low RH maintained throughout) to very high (wet latex cast on the gradient bar and high humidity during drying). A predried film exhibits a {open_quotes}dry{close_quotes} MFT transition, from opaque to clear film, only a few degrees above the {open_quotes}wet{close_quotes} MFT, indicating that so-called capillary forces associated with the presence of liquid water may be helpful but are not critical to film compaction. Indeed, with hydrophobic polymer compositions, the two MFT transitions converge with time. With hydrophilic compositions the {open_quotes}wet{close_quotes} MFT remains lower by several degrees, and this is ascribed to plasticization by water.

  17. Environmental fate of processed natural rubber latex.

    PubMed

    Lambert, Scott; Sinclair, Chris J; Bradley, Emma L; Boxall, Alistair B A

    2013-07-01

    In this study, processed natural rubber latex was degraded in outdoor aquatic microcosms, under a number of treatment scenarios for 200 days. The analytical strategy adopted aimed to characterise a range of volatile, semi-volatile and non-volatile substances. Zinc, was shown to migrate from the latex into solution and increase in concentration over time. Dissolved compounds for which predicted formulas were generated largely consisted of oxygen containing compounds, and are potential oxidised polyisoprene oligomers of various chain lengths. A classification of samples based on principal component analysis showed a clear separation of the degraded latex samples from the representative controls. This technique identified an increase in the complexity of the substances produced and showed that these substances undergo further degradation and transformation processes. A number of volatile substances were also identified indicating the atmosphere to be a potential receiving environmental compartment for polymer degradates. Overall, the results show that complex mixtures of substances are produced when polymer-based materials degrade under environmental conditions.

  18. Heterogeneity in styrene-butadiene latex films.

    PubMed

    Santos, Juliane P; Corpart, Pascale; Wong, Kenneth; Galembeck, Fernando

    2004-11-23

    Low-Tg styrene-butadiene (SB) latex films were investigated by noncontact atomic force microscopy and scanning electric potential microscopy, revealing a number of different morphologies and electric potential patterns across films cast from the same SB latex dispersions under the same conditions. Surface leveling and charge dispersion throughout the films are, thus, restrained even at temperatures above Tg and the minimum film-formation temperature. An unprecedented electric pattern is observed, in which the particle cores are more positive than the contacting particle outer layers. Different packing patterns, including cubic and hexagonal arrays, coexist in neighboring areas. Zonal centrifugation of the SB latex in sucrose density gradient shows that particles cover a broad range of densities. Thus, film surface heterogeneity is at least partly due to particle heterogeneity. Fractal dimensions of topographic profiles are lower than those of the electric potential profiles, showing that charge mobility is much more restrained than polymer chain motion at the film surface and that it imposes a limit to the charged chain-ends motion.

  19. Rapid and quantitative detection of C-reactive protein based on quantum dots and immunofiltration assay

    PubMed Central

    Zhang, Pengfei; Bao, Yan; Draz, Mohamed Shehata; Lu, Huiqi; Liu, Chang; Han, Huanxing

    2015-01-01

    Convenient and rapid immunofiltration assays (IFAs) enable on-site “yes” or “no” determination of disease markers. However, traditional IFAs are commonly qualitative or semi-quantitative and are very limited for the efficient testing of samples in field diagnostics. Here, we overcome these limitations by developing a quantum dots (QDs)-based fluorescent IFA for the quantitative detection of C-reactive proteins (CRP). CRP, the well-known diagnostic marker for acute viral and bacterial infections, was used as a model analyte to demonstrate performance and sensitivity of our developed QDs-based IFA. QDs capped with both polyethylene glycol (PEG) and glutathione were used as fluorescent labels for our IFAs. The presence of the surface PEG layer, which reduced the non-specific protein interactions, in conjunction with the inherent optical properties of QDs, resulted in lower background signal, increased sensitivity, and ability to detect CRP down to 0.79 mg/L with only 5 µL serum sample. In addition, the developed assay is simple, fast and can quantitatively detect CRP with a detection limit up to 200 mg/L. Clinical test results of our QD-based IFA are well correlated with the traditional latex enhance immune-agglutination aggregation. The proposed QD-based fluorescent IFA is very promising, and potentially will be adopted for multiplexed immunoassay and in field point-of-care test. PMID:26491289

  20. Rapid and quantitative detection of C-reactive protein based on quantum dots and immunofiltration assay.

    PubMed

    Zhang, Pengfei; Bao, Yan; Draz, Mohamed Shehata; Lu, Huiqi; Liu, Chang; Han, Huanxing

    2015-01-01

    Convenient and rapid immunofiltration assays (IFAs) enable on-site "yes" or "no" determination of disease markers. However, traditional IFAs are commonly qualitative or semi-quantitative and are very limited for the efficient testing of samples in field diagnostics. Here, we overcome these limitations by developing a quantum dots (QDs)-based fluorescent IFA for the quantitative detection of C-reactive proteins (CRP). CRP, the well-known diagnostic marker for acute viral and bacterial infections, was used as a model analyte to demonstrate performance and sensitivity of our developed QDs-based IFA. QDs capped with both polyethylene glycol (PEG) and glutathione were used as fluorescent labels for our IFAs. The presence of the surface PEG layer, which reduced the non-specific protein interactions, in conjunction with the inherent optical properties of QDs, resulted in lower background signal, increased sensitivity, and ability to detect CRP down to 0.79 mg/L with only 5 µL serum sample. In addition, the developed assay is simple, fast and can quantitatively detect CRP with a detection limit up to 200 mg/L. Clinical test results of our QD-based IFA are well correlated with the traditional latex enhance immune-agglutination aggregation. The proposed QD-based fluorescent IFA is very promising, and potentially will be adopted for multiplexed immunoassay and in field point-of-care test.

  1. Eutirucallin, a RIP-2 Type Lectin from the Latex of Euphorbia tirucalli L. Presents Proinflammatory Properties

    PubMed Central

    Santana, Sanzio Silva; Gennari-Cardoso, Margareth Leitão; Carvalho, Fernanda Caroline; Roque-Barreira, Maria Cristina; Santiago, André da Silva; Alvim, Fátima Cerqueira; Pirovani, Carlos Priminho

    2014-01-01

    Lectins are carbohydrate-binding proteins that recognize and modulate physiological activities and have been used as a toll for detection and identification of biomolecules, and therapy of diseases. In this study we have isolated a lectin present in the latex of Euphorbia tirucalli, and named it Eutirucallin. The latex protein extract was subjected to ion exchange chromatography and showed two peaks with haemagglutinating activity. Polypeptides of 32 kDa protein extract strongly interacted with immobilized galactose (α-lactose > D-N-acetylgalactosamine). The Eutirucallin was obtained with a yield of 5.6% using the α-lactose column. The lectin domain has 32 kDa subunits and at least two of which are joined by disulfide bridges. The agglutinating capacity for human erythrocytes A+, B+ and O+ is inhibited by D-galactose. The haemagglutinating activity of Eutirucallin was independent of Ca2+ and maintained until the temperature of 55°C. Eutirucallin presented biological activities such as neutrophils recruitment and cytokine prodution by macrophages. The analysis of the trypsin-digested Eutirucallin by ms/ms in ESI-Q-TOFF resulted in nine peptides similar to type 2 ribosome-inactivating protein (type-2 RIP). It's partial sequence showed a similarity of 67.4 – 83.1% for the lectin domain of type-2 RIP [Ricin and Abrin (83.1%), Viscumin, Ebulin, Pulchellin, Cinnamomin, Volkensin and type-2 RIP Iris hollandica]. Our data suggest that Eutirucallin is a new member of type 2 ribosome-inactivating protein and presents biotechnological potential. PMID:24558388

  2. An early Cambrian agglutinated tubular lophophorate with brachiopod characters

    PubMed Central

    Zhang, Z.-F.; Li, G.-X.; Holmer, L. E.; Brock, G. A.; Balthasar, U.; Skovsted, C. B.; Fu, D.-J.; Zhang, X.-L.; Wang, H.-Z.; Butler, A.; Zhang, Z.-L.; Cao, C.-Q.; Han, J.; Liu, J.-N.; Shu, D.-G.

    2014-01-01

    The morphological disparity of lophotrochozoan phyla makes it difficult to predict the morphology of the last common ancestor. Only fossils of stem groups can help discover the morphological transitions that occurred along the roots of these phyla. Here, we describe a tubular fossil Yuganotheca elegans gen. et sp. nov. from the Cambrian (Stage 3) Chengjiang Lagerstätte (Yunnan, China) that exhibits an unusual combination of phoronid, brachiopod and tommotiid (Cambrian problematica) characters, notably a pair of agglutinated valves, enclosing a horseshoe-shaped lophophore, supported by a lower bipartite tubular attachment structure with a long pedicle with coelomic space. The terminal bulb of the pedicle provided anchorage in soft sediment. The discovery has important implications for the early evolution of lophotrochozoans, suggesting rooting of brachiopods into the sessile lophotrochozoans and the origination of their bivalved bauplan preceding the biomineralization of shell valves in crown brachiopods. PMID:24828016

  3. Human blood group typing based on digital photographs of RBC agglutination process

    NASA Astrophysics Data System (ADS)

    Doubrovski, V. A.; Dolmashkin, A. A.

    2010-08-01

    A method for the monitoring of the human erythrocyte agglutination reaction in vitro, which is the basis for determining the human blood type (group), is proposed. The method is based on a statistical analysis of digital photographs of the agglutination process. It is experimentally shown that this analysis of photographs makes it possible to determine the probability that the agglutination reaction of erythrocytes of the studied specimen of blood with corresponding isohemagglutinating sera does occur. To increase the rate of the agglutination reaction of erythrocytes and to improve the sensitivity of the method of monitoring, the bioobject under study is subjected to the action of ultrasonic waves, as was previously proposed by the authors, and the result of the erythrocyte agglutination reaction is read optically. It is shown that, in principle, the method of statistical processing of digital photographs can be used to develop devices for automatic human blood typing in the AB0 and Rh systems.

  4. Sperm-agglutinating antibodies and testicular morphology in fifty-nine men with azoospermia or cryptozoospermia.

    PubMed

    Friberg, J; Kjessler, B

    1975-04-01

    The relationship between the state of the germinal epithelium and the type and titer of circulating sperm-agglutinating antibodies has been investigated in a series of 59 azoospermic or occasionally cryptozoospermic men. The patients were grouped according to the condition of the germinal epithelium as observed from testicular biopsy specimens, as well as to type and titer of circulating sperm-agglutinating antibodies investigated by a previously described microagglutination technique. Evidence is presented to suggest that the presence of mature spermatozoa in the testicular structures may be a prerequisite for the spontaneous production of circulating sperm-agglutinating antibodies, at least of the head-to-tail (H-T) agglutinating type. Furthermore, these circulating H-T sperm-agglutinating antibodies, once they are formed, do not seem to interfere adversely with the germinal epithelium of the carrier.

  5. siRNA delivery targeting to the lung via agglutination-induced accumulation and clearance of cationic tetraamino fullerene

    NASA Astrophysics Data System (ADS)

    Minami, Kosuke; Okamoto, Koji; Doi, Kent; Harano, Koji; Noiri, Eisei; Nakamura, Eiichi

    2014-05-01

    The efficient treatment of lung diseases requires lung-selective delivery of agents to the lung. However, lung-selective delivery is difficult because the accumulation of micrometer-sized carriers in the lung often induces inflammation and embolization-related toxicity. Here we demonstrate a lung-selective delivery system of small interfering RNA (siRNA) by controlling the size of carrier vehicle in blood vessels. The carrier is made of tetra(piperazino)fullerene epoxide (TPFE), a water-soluble cationic tetraamino fullerene. TPFE and siRNA form sub-micrometer-sized complexes in buffered solution and these complexes agglutinate further with plasma proteins in the bloodstream to form micrometer-sized particles. The agglutinate rapidly clogs the lung capillaries, releases the siRNA into lung cells to silence expression of target genes, and is then cleared rapidly from the lung after siRNA delivery. We applied our delivery system to an animal model of sepsis, indicating the potential of TPFE-based siRNA delivery for clinical applications.

  6. Rapid Detection of the Varicella Zoster Virus

    NASA Technical Reports Server (NTRS)

    Lewis, Michelle P.; Harding, Robert

    2011-01-01

    in blood. Other tests include running a sample in a polymerase chain reaction analyzer, enzyme immunoassay, latex agglutination, indirect fluorescent antibody and fluorescent antibody to membrane antigen assay. These existing tests require laboratory analysis by trained personnel, expensive equipment, invasive procedures and a longer period of time to obtain test results.

  7. Large-size monodisperse latexes as a commercial space product

    NASA Technical Reports Server (NTRS)

    Kornfeld, D. M.

    1977-01-01

    Proposed spacelab production of large-size (2-40 micron diameter) monodispersed latexes is discussed. Explanations are given for the present lack of monodisperse particles in this size range. The four main topics discussed are: (1) the potential uses of these large particle size latexes, (2) why it is necessary for the particles to have a very narrow size distribution, (3) why large amounts of these monodisperse latexes are needed, and (4) why it is necessary to go to microgravity to prepare these latexes.

  8. ADSORPTION STUDIES IN A SYNTHETIC RUBBER LATEX-OVALBUMIN SYSTEM

    PubMed Central

    Williams, H. B.; Choppin, A. R.

    1950-01-01

    1. Adsorption of ovalbumin on the latex surface was in excess of the quantity required to produce coverage of the surface over most of the protein concentrations range which was investigated. 2. "S" shaped isothermals which probably indicated multilayer adsorption were obtained. 3. The quantity of ovalbumin required to produce a constant surface charge density on the latex particle surface was a function of the pH, and a theory of active centers on the latex particles has been suggested. 4. A shift in the isoelectric point from that of native ovalbumin has been observed for the protein when adsorbed on a synthetic latex. PMID:14824490

  9. New constitutive latex osmotin-like proteins lacking antifungal activity.

    PubMed

    Freitas, Cleverson D T; Silva, Maria Z R; Bruno-Moreno, Frederico; Monteiro-Moreira, Ana C O; Moreira, Renato A; Ramos, Márcio V

    2015-11-01

    Proteins that share similar primary sequences to the protein originally described in salt-stressed tobacco cells have been named osmotins. So far, only two osmotin-like proteins were purified and characterized of latex fluids. Osmotin from Carica papaya latex is an inducible protein lacking antifungal activity, whereas the Calotropis procera latex osmotin is a constitutive antifungal protein. To get additional insights into this subject, we investigated osmotins in latex fluids of five species. Two potential osmotin-like proteins in Cryptostegia grandiflora and Plumeria rubra latex were detected by immunological cross-reactivity with polyclonal antibodies produced against the C. procera latex osmotin (CpOsm) by ELISA, Dot Blot and Western Blot assays. Osmotin-like proteins were not detected in the latex of Thevetia peruviana, Himatanthus drasticus and healthy Carica papaya fruits. Later, the two new osmotin-like proteins were purified through immunoaffinity chromatography with anti-CpOsm immobilized antibodies. Worth noting the chromatographic efficiency allowed for the purification of the osmotin-like protein belonging to H. drasticus latex, which was not detectable by immunoassays. The identification of the purified proteins was confirmed after MS/MS analyses of their tryptic digests. It is concluded that the constitutive osmotin-like proteins reported here share structural similarities to CpOsm. However, unlike CpOsm, they did not exhibit antifungal activity against Fusarium solani and Colletotrichum gloeosporioides. These results suggest that osmotins of different latex sources may be involved in distinct physiological or defensive events.

  10. Degree of dispersion of latex particles in cement paste, as assessed by electrical resistivity measurement

    SciTech Connect

    Fu, X.; Chung, D.D.L.

    1996-12-31

    The degree of dispersion of latex particles in latex-modified cement paste was assessed by measurement of the volume electrical resistivity and modeling this resistivity in terms of latex and cement phases that are partly in series and partly in parallel. The assessment was best at low values of the latex-cement ratio; it underestimated the degree of latex dispersion when the latex/cement ratio was high, especially > 0.2.

  11. Latex allergens in tire dust and airborne particles.

    PubMed Central

    Miguel, A G; Cass, G R; Weiss, J; Glovsky, M M

    1996-01-01

    The prevalence and severity of latex allergy has increased dramatically in the last 15 years due to exposure to natural rubber products. Although historically this health risk has been elevated in hospital personnel and patients, a recent survey has indicated a significant potential risk for the general population. To obtain a wide-spread source for latex exposure, we have considered tire debris. We have searched for the presence of latex allergens in passenger car and truck tire tread, in debris deposited from the atmosphere near a freeway, and in airborne particulate matter samples representative of the entire year 1993 at two sites in the Los Angeles basin (California). After extraction of the samples with phosphate buffered saline, a modified-ELISA inhibition assay was used to measure relative allergen potency and Western blot analyses were used to identify latex allergens. The inhibition studies with the human IgE latex assay revealed inhibition by the tire tread source samples and ambient freeway dust, as well as by control latex sap and latex glove extracts. Levels of extractable latex allergen per unit of protein extracted were about two orders of magnitude lower for tire tread as compared to latex gloves. Western blot analyses using binding of human IgE from latex-sensitive patients showed a band at 34-36 kDa in all tire and ambient samples. Long Beach and Los Angeles, California, air samples showed four additional bands between 50 and 135 kDa. Alternative Western blot analyses using rabbit IgG raised against latex proteins showed a broad band at 30-50 kDa in all samples, with additional bands in the urban air samples similar to the IgE results. A latex cross-reactive material was identified in mountain cedar. In conclusion, the latex allergens or latex cross-reactive material present in sedimented and airborne particulate material, derived from tire debris, and generated by heavy urban vehicle traffic could be important factors in producing latex allergy

  12. Involvement of HbPIP2;1 and HbTIP1;1 aquaporins in ethylene stimulation of latex yield through regulation of water exchanges between inner liber and latex cells in Hevea brasiliensis.

    PubMed

    Tungngoen, Kessarin; Kongsawadworakul, Panida; Viboonjun, Unchera; Katsuhara, Maki; Brunel, Nicole; Sakr, Soulaiman; Narangajavana, Jarunya; Chrestin, Hervé

    2009-10-01

    Natural rubber is synthesized in specialized articulated cells (laticifers) located in the inner liber of Hevea brasiliensis. Upon bark tapping, the laticifer cytoplasm (latex) is expelled due to liber tissue turgor pressure. In mature virgin (untapped) trees, short-term kinetic studies confirmed that ethylene, the rubber yield stimulant used worldwide, increased latex yield, with a concomitant decrease in latex total solid content, probably through water influx in the laticifers. As the mature laticifers are devoid of plasmodesmata, the rapid water exchanges with surrounding liber cells probably occur via the aquaporin pathway. Two full-length aquaporin cDNAs (HbPIP2;1 and HbTIP1;1, for plasma membrane intrinsic protein and tonoplast intrinsic protein, respectively) were cloned and characterized. The higher efficiency of HbPIP2;1 than HbTIP1;1 in increasing plasmalemma water conductance was verified in Xenopus laevis oocytes. HbPIP2;1 was insensitive to HgCl(2). In situ hybridization demonstrated that HbPIP2;1 was expressed in all liber tissues in the young stem, including the laticifers. HbPIP2;1 was up-regulated in both liber tissues and laticifers, whereas HbTIP1;1 was down-regulated in liber tissues but up-regulated in laticifers in response to bark Ethrel treatment. Ethylene-induced HbPIP2;1 up-regulation was confirmed by western-blot analysis. The promoter sequences of both genes were cloned and found to harbor, among many others, ethylene-responsive and other chemical-responsive (auxin, copper, and sulfur) elements known to increase latex yield. Increase in latex yield in response to ethylene was emphasized to be linked with water circulation between the laticifers and their surrounding tissues as well as with the probable maintenance of liber tissue turgor, which together favor prolongation of latex flow.

  13. Slide Agglutination Method for the Serological Identification of Neisseria gonorrhoeae with Anti-Gonococcal Antibodies Adsorbed to Protein A-Containing Staphylococci

    PubMed Central

    Danielsson, Dan; Kronvall, Göran

    1974-01-01

    A rapid slide agglutination test has been developed for the identification of Neisseria gonorrhoeae that are primarily detected as oxidase-positive colonies in gonococcal cultures. The technique is based on the specific nonimmune reactivity between the Fc portion of immunoglobulin (Ig)G and staphylococcal protein A. IgG molecules adsorbed to stabilized staphylococci will thereby become oriented with their antigen-reactive sites that are directed outwards. Protein A-containing staphylococci with unabsorbed anti-gonococcal antibodies gave positive co-agglutination reactions with gonococci but also with meningococci, some Moraxella, Haemophilus, and Pseudomonas strains. These crossreactions were eliminated by absorption of the anti-gonococcal antiserum with meningococcal and Moraxella organisms prior to the coating of reagent staphylococci. In the routine culture diagnosis of N. gonorrhoeae the use of specific gonococcal reagent staphylococci gave concordant results with fermentation procedures and immunofluorescent techniques. Images PMID:4207280

  14. Polymer latex particles: Preparation, characterization, and coating patterns

    SciTech Connect

    Wang, Leeyih.

    1993-01-01

    The coating patterns of polystyrene latex after spin drying have been intensively investigated. The model microsphere was prepared using emulsifier-free emulsion polymerization. The resulting polystyrene latex was 0.54 [mu]m in diameter with the polydispersity of 1.02. The mobility of latex spheres in concentrated dispersions was studied by diffusing wave spectroscopy (DWS). The diffusion coefficient of the polystyrene spheres dispersed in water decreased as the concentration of latex particles increased. The concentration dependence of the diffusion coefficient of this latex determined by DWS matched closely to the short-time diffusion of poly(methyl methacrylate) latex in a mixed organic fluid determined by PCS using the refractive index matching method. It indicates that the electrical repulsive force between particles in this system has a small effect on the short-time mobility of particles. This result was also confirmed by the diffusion coefficients of polystyrene spheres dispersed in water with the addition of sodium chloride, or dispersed in NMF. The presence of surfactants, SDS and C12E5, in the dispersed medium led to a great reduction on the diffusivity of latex spheres. A two dimensional ordered array of particles can be obtained from the spin drying of polystyrene latex by adding surfactants in a suitable concentration range or by choosing an appropriate substrate and/or dispersing fluid. A mechanism for the formation of hexagonally packed particles was proposed as the actions of three factors: retractive, frictional, and capillary forces.

  15. Latex Surface and Bulk Coagulation Induced by Solvent Vapors.

    PubMed

    Braga; da Silva Md; Cardoso; Galembeck

    2000-08-01

    Latex exposure to solvent vapors leads to highly specific changes in latex stability as well as on the morphologies of the particle association products, depending on the latex and solvent used. Examples of solvent vapor-induced aggregation are given: surface films are obtained on two PS latexes; in one case, the film surface is mirror-reflective and very flat, as evidenced by AFM. Another PS latex coagulates under exposure to acetone vapors, and the morphologies of the coagula are highly sensitive to the exposure conditions. This latex yields a highly porous foam-like structure, in which particles are strongly coalesced but form percolating patches around the pores. The same latex but under other conditions produces a coagulum of large numbers of aggregated particles with a raspberry-like morphology. Density centrifugation experiments show that the effect of solvents on different latex fractions is not uniform, and some fractions show larger density changes than others, thus evidencing a variability in their swelling ability. Copyright 2000 Academic Press.

  16. Natural rubber latex allergy and dental practice.

    PubMed

    Desai, Shalin V

    2007-12-01

    Natural rubber latex (NRL) allergy is a significant clinical problem with potentially life-threatening complications. Oral health care professionals must be able to screen for NRL allergy and refer patients or staff to a specialist for definitive diagnosis. Protocol for its management must be developed and incorporated into daily practice. Practitioners must be able to recognize and treat NRL exposure emergencies. Knowledge of the availability of substitute products and an adequate fresh stock of such products in dental practice can minimise the risk of adverse NRL sensitivity.

  17. New approach for papaya latex storage without virus degradation

    PubMed Central

    Rodrigues, Silas P.; Andrade, Josemar S.; Ventura, José A.; Fernandes, Patricia M. B.

    2009-01-01

    Papaya meleira virus (PMeV) is the causal agent of papaya (Carica papaya L.) sticky disease, which has been detected through analysis of its double-stranded RNA (dsRNA) genome from plant latex. In this work we demonstrate that PMeV dsRNA is protected during 25 days when latex is diluted in citrate buffer pH 5.0 (1:1 v/v) and maintained at -20ºC. At the same temperature, some protection was observed for pure latex or latex diluted in ultra-pure water. Conversely, the dsRNA was almost completely degraded after 25 days when maintained at 25ºC, indicating the need for freezing. The proper procedures to collect and store papaya latex described here will contribute to efficient and large scale use of molecular diagnosis of PMeV. PMID:24031329

  18. Performance of CHROMagar Staph aureus and CHROMagar MRSA for detection of Staphylococcus aureus in seawater and beach sand--comparison of culture, agglutination, and molecular analyses.

    PubMed

    Goodwin, K D; Pobuda, M

    2009-11-01

    Beach seawater and sand were analyzed for Staphylococcus aureus and methicillin resistant S. aureus (MRSA) for samples collected from Avalon, and Doheny Beach, CA. Membrane filtration followed by incubation on CHROMagar Staph aureus (SCA) and CHROMagar MRSA (C-MRSA) was used to enumerate S. aureus and MRSA, respectively. Media performance was evaluated by comparing identification via colony morphology and latex agglutination tests to PCR (clfA, 16S, and mecA genes). Due to background color and crowding, picking colonies from membrane filters and streaking for isolation were sometimes necessary. The specificity of SCA and C-MRSA was improved if colony isolates were identified by the presence of a matte halo in addition to mauve color; however routine agglutination testing of isolates did not appear warranted. Using the appearance of a colony on the membrane filter in conjunction with isolate appearance, the positive % agreement, the negative % agreement, and the % positive predictive accuracy for SCA was 84%, 95%, and 99% respectively, and for C-MRSA it was 85%, 98%, and 92%, respectively. Sensitivity and specificity of SCA and C-MRSA with membrane-filtered beach samples were optimized through identification experience, control of filter volume and incubation time, and isolation of colonies needing further identification. With optimization, SCA and C-MRSA could be used for enumeration of S. aureus and MRSA from samples of beach water and sand. For the sites studied here, the frequency of detection of S. aureus ranged from 60 to 76% and 53 to 79% for samples of beach seawater and sand, respectively. The frequency of detection of MRSA ranged from 2 to 9% and 0 to 12% for samples of seawater and sand, respectively.

  19. Human fibrinogen monolayers on latex particles: role of ionic strength.

    PubMed

    Bratek-Skicki, Anna; Żeliszewska, Paulina; Adamczyk, Zbigniew; Cieśla, Michał

    2013-03-19

    The adsorption of human serum fibrinogen on polystyrene latex particles was studied using the microelectrophoretic and concentration depletion methods. Measurements were carried out for pH 3.5 and an ionic strength range of 10(-3) to 0.15 M NaCl. The electrophoretic mobility of latex was determined as a function of the amount of adsorbed fibrinogen (surface concentration). A monotonic increase in the electrophoretic mobility (zeta potential) of the latex was observed, indicating a significant adsorption of fibrinogen on latex for all ionic strengths. No changes in the latex mobility were observed for prolonged time periods, suggesting the irreversibility of fibrinogen adsorption. The maximum coverage of fibrinogen on latex particles was precisely determined using the depletion method. The residual protein concentration after making contact with latex particles was determined by electrokinetic measurements and AFM imaging where the surface coverage of fibrinogen on mica was quantitatively determined. The maximum fibrinogen coverage increased monotonically with ionic strength from 1.8 mg m(-2) for 10(-3) M NaCl to 3.6 mg m(-2) for 0.15 M NaCl. The increase in the maximum coverage was interpreted in terms of the reduced electrostatic repulsion among adsorbed fibrinogen molecules. The experimental data agree with theoretical simulations made by assuming a 3D unoriented adsorption of fibrinogen. The stability of fibrinogen monolayers on latex was also determined in ionic strength cycling experiments. It was revealed that cyclic variations in NaCl concentration between 10(-3) and 0.15 M induced no changes in the latex electrophoretic mobility, suggesting that there were no irreversible molecule orientation changes in the monolayers. On the basis of these experimental data, a robust procedure of preparing fibrinogen monolayers on latex particles of well-controlled coverage was proposed.

  20. Latex allergy: a follow up study of 1040 healthcare workers

    PubMed Central

    Filon, F Larese; Radman, G

    2006-01-01

    Background Natural rubber latex allergy can cause skin and respiratory symptoms The aim of this study was to evaluate the prevalence and incidence of latex related symptoms and sensitisation among a large group of healthcare workers in Trieste hospitals, followed for three years before and after the introduction of powder‐free gloves with low latex release. Methods In the years 1997–99 the authors evaluated 1040 healthcare workers exposed to latex allergen for latex related symptoms and sensitisation by means of a questionnaire, a medical examination, skin prick tests, and IgE specific antibody assay. The second evaluation was carried out in the years 2000–02, subsequent to the changeover to a powder‐free environment. Results Glove related symptoms were seen in 21.8% of the nurses (227), mostly consisting of mild dermatitis: 38 (3.6%) complaining of contact urticaria and 24 (2.3%) of asthma and/or rhinitis. These symptoms were significantly related to skin prick tests positive to latex (OR = 9.70; 95% CI 5.5 to 17) and to personal atopy (OR = 2.29; 95% CI 1.6 to 3.2). Follow up was completed in 960 subjects (92.3%): 19 new subjects (2.4%) complained of itching erythema when using gloves, but none was prick positive to latex. Symptoms significantly improved and in most cases disappeared (p<0.0001). Conclusions Simple measures such as the avoidance of unnecessary glove use, the use of non‐powdered latex gloves by all workers, and use of non‐latex gloves by sensitised subjects can stop the progression of latex symptoms and can avoid new cases of sensitisation. PMID:16421390

  1. Polyphenoloxidase Silencing Affects Latex Coagulation in Taraxacum Species1[W

    PubMed Central

    Wahler, Daniela; Gronover, Christian Schulze; Richter, Carolin; Foucu, Florence; Twyman, Richard M.; Moerschbacher, Bruno M.; Fischer, Rainer; Muth, Jost; Prüfer, Dirk

    2009-01-01

    Latex is the milky sap that is found in many different plants. It is produced by specialized cells known as laticifers and can comprise a mixture of proteins, carbohydrates, oils, secondary metabolites, and rubber that may help to prevent herbivory and protect wound sites against infection. The wound-induced browning of latex suggests that it contains one or more phenol-oxidizing enzymes. Here, we present a comprehensive analysis of the major latex proteins from two dandelion species, Taraxacum officinale and Taraxacum kok-saghyz, and enzymatic studies showing that polyphenoloxidase (PPO) is responsible for latex browning. Electrophoretic analysis and amino-terminal sequencing of the most abundant proteins in the aqueous latex fraction revealed the presence of three PPO-related proteins generated by the proteolytic cleavage of a single precursor (pre-PPO). The laticifer-specific pre-PPO protein contains a transit peptide that can target reporter proteins into chloroplasts when constitutively expressed in dandelion protoplasts, perhaps indicating the presence of structures similar to plastids in laticifers, which lack genuine chloroplasts. Silencing the PPO gene by constitutive RNA interference in transgenic plants reduced PPO activity compared with wild-type controls, allowing T. kok-saghyz RNA interference lines to expel four to five times more latex than controls. Latex fluidity analysis in silenced plants showed a strong correlation between residual PPO activity and the coagulation rate, indicating that laticifer-specific PPO plays a major role in latex coagulation and wound sealing in dandelions. In contrast, very little PPO activity is found in the latex of the rubber tree Hevea brasiliensis, suggesting functional divergence of latex proteins during plant evolution. PMID:19605551

  2. Polyphenoloxidase silencing affects latex coagulation in Taraxacum species.

    PubMed

    Wahler, Daniela; Gronover, Christian Schulze; Richter, Carolin; Foucu, Florence; Twyman, Richard M; Moerschbacher, Bruno M; Fischer, Rainer; Muth, Jost; Prüfer, Dirk

    2009-09-01

    Latex is the milky sap that is found in many different plants. It is produced by specialized cells known as laticifers and can comprise a mixture of proteins, carbohydrates, oils, secondary metabolites, and rubber that may help to prevent herbivory and protect wound sites against infection. The wound-induced browning of latex suggests that it contains one or more phenol-oxidizing enzymes. Here, we present a comprehensive analysis of the major latex proteins from two dandelion species, Taraxacum officinale and Taraxacum kok-saghyz, and enzymatic studies showing that polyphenoloxidase (PPO) is responsible for latex browning. Electrophoretic analysis and amino-terminal sequencing of the most abundant proteins in the aqueous latex fraction revealed the presence of three PPO-related proteins generated by the proteolytic cleavage of a single precursor (pre-PPO). The laticifer-specific pre-PPO protein contains a transit peptide that can target reporter proteins into chloroplasts when constitutively expressed in dandelion protoplasts, perhaps indicating the presence of structures similar to plastids in laticifers, which lack genuine chloroplasts. Silencing the PPO gene by constitutive RNA interference in transgenic plants reduced PPO activity compared with wild-type controls, allowing T. kok-saghyz RNA interference lines to expel four to five times more latex than controls. Latex fluidity analysis in silenced plants showed a strong correlation between residual PPO activity and the coagulation rate, indicating that laticifer-specific PPO plays a major role in latex coagulation and wound sealing in dandelions. In contrast, very little PPO activity is found in the latex of the rubber tree Hevea brasiliensis, suggesting functional divergence of latex proteins during plant evolution.

  3. Momordica charantia seed lectin: toxicity, bacterial agglutination and antitumor properties.

    PubMed

    Kabir, Syed Rashel; Nabi, Md Mahamodun; Nurujjaman, Md; Abu Reza, Md; Alam, A H M Khurshid; Uz Zaman, Rokon; Khalid-Bin-Ferdaus, Khandaker Md; Amin, Ruhul; Khan, Md Masudul Hasan; Hossain, Md Anowar; Uddin, Md Salim; Mahmud, Zahid Hayat

    2015-03-01

    In last three decades, several studies were carried out on the D-galactose-specific lectin of Momordica charantia seeds (MCL). In the present study, in vitro growth inhibition (8-23 %) at different concentrations (6-24 μg/ml) of MCL was observed against Ehrlich ascites carcinoma (EAC) cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. MCL also showed 28, 45, and 75 % growth inhibitions against EAC cells when administered 1.2, 2.0, and 2.8 mg/kg/day (i.p.), respectively for five consequent days in vivo in mice. After lectin treatment, the level of red blood cell and hemoglobin was increased significantly with the decrease of white blood cell and maintained the normal level when compared with EAC-bearing control and normal mice without EAC cells. Although MCL caused cell cycle arrest at G0/G1 phase of EAC cells, any irregular shape or apoptotic morphological alterations in the lectin-treated EAC cells was not observed by an optical and fluorescence microscope. Lectin showed toxicity against brine shrimp nauplii with an LC50 value of 49.7 μg/ml. Four out of seven pathogenic bacteria were agglutinated by MCL in the absence of inhibitory sugar D-lactose/D-galactose. In conclusion, MCL showed strong cytotoxic effect and therefore can be used as a potent anticancer chemotherapeutic agent.

  4. A randomised trial of the durability of non-allergenic latex-free surgical gloves versus latex gloves.

    PubMed Central

    Newsom, S. W.; Smith, M. O.; Shaw, P.

    1998-01-01

    A prospective randomised trial was performed to compare the robustness of a new non-latex surgical glove with a standard latex glove when worn by four general surgeons in a district general hospital. Gloves were retrieved after surgery and examined using the European Standard Test for punctures. The overall puncture rate was 10.1%, and there was no significant difference in the rates between the two types of glove, although punctures in the non-latex glove tended to be larger and more readily noted by the wearer. The increase in latex allergy among health care staff dictates the need for gloves made from other materials, which may also be useful for operations on latex-allergic patients. PMID:9771234

  5. Coalescence of polymeric particles in latex films

    SciTech Connect

    Cabane, B.

    1996-01-01

    Common coatings such as paints or adhesives can be made from aqueous dispersions which are evaporated on the substrate to give a continuous film. The most widely studied systems are latex dispersions, which contain submicrometric particles of soft organic polymers dispersed in water. With such systems, the difficulty is to ensure that the resulting film will be resistant to water, despite the fact that it has been prepared as a stable aqueous dispersion. For this purpose the dispersion must pass through some irreversible transformations. A radical transformation is the coalescence of particles, which yields a continuous polymer film. This transformation will be described for surfactant-covered latex particles, which coalesce in the wet state, and for polyelectrolyte-covered particles, which coalesce in the dry state. The consequences of coalescence will be examined, in particular the expulsion of the surfactants towards the outer boundaries of the film. This may be detrimental to the adhesive properties of the film: thus alternative routes for maintaining resistance to water without using coalescence of the particles will also be examined. {copyright} {ital 1996 American Institute of Physics.}

  6. Bioseparation of papain from Carica papaya latex by precipitation of papain-poly (vinyl sulfonate) complexes.

    PubMed

    Braia, Mauricio; Ferrero, Maximiliano; Rocha, María Victoria; Loureiro, Dana; Tubio, Gisela; Romanini, Diana

    2013-09-01

    The formation of insoluble complexes between enzymes and polyelectrolytes is a suitable technique for isolating these biomolecules from natural sources, because it is a simple and rapid technique that allows the concentration of the protein. This technique can be used in most purification protocols at the beginning of the downstream process. The aim of this investigation is to isolate papain from Carica papaya latex by precipitation of insoluble complexes between this enzyme and poly (vinyl sulfonate). The papain-poly (vinyl sulfonate) complex was insoluble at pH lower than 6, with a PVS/PAP stoichiometric ratio of 1:279. Ionic strength affected the complex formation. The presence of the polymer increased the enzymatic activity and protected the enzyme from autodegradation. The optimal conditions for the formation of insoluble papain-polyelectrolyte complex formation were applied to C. papaya latex and a high recovery was obtained (around 86%) and a purification factor around 2. This method can be applied as an isolation method of papain from C. papaya latex or as a first step in a larger purification strategy.

  7. Aeromonas hydrophila typing scheme based on patterns of agglutination with erythrocytes and yeast cells.

    PubMed Central

    Adams, D; Atkinson, H M; Woods, W H

    1983-01-01

    An agglutination typing scheme has been developed for strains of Aeromonas hydrophila. Primary agglutination typing is based on testing agar-grown A. hydrophila cells with human, horse, rat, and guinea pig erythrocytes and Saccharomyces cerevisiae cells. Further subdivision of primary groups is based firstly on whether yeast cell agglutination is inhibited by a D-mannose polymer, yeast mannan, and secondly on patterns of inhibition of hemagglutination by yeast mannan and the monomeric sugars L-fucose, D-galactose, and D-mannose. A total of 320 isolates were tested, and these were divisible into 39 distinct types on the basis of this scheme. Application of this typing scheme in the future to isolates of A. hydrophila known to be associated with human infection may enable correlations to be made between particular agglutination types and human pathogenicity. PMID:6841579

  8. Light-scattering analysis of ultrasonic wave's influence on the RBC agglutination in vitro

    NASA Astrophysics Data System (ADS)

    Doubrovski, Valeri A.; Dvoretski, Costanten N.

    1999-04-01

    Elastic light scattering is one of the most often used optical methods to analyze the cells agglutination reaction - the base of a great number of medical diagnostic test and biomedical investigations. The increase of the resolution of methods and apparatus towards the induced cells aggregation - the foundation of the reaction of agglutination, is quite an actual problem. The solution of this problem increases the reliability of the diagnostic test and gives an opportunity to achieve the diagnostic information in the cases when the traditional approaches do not lead to the diagnostic results. The attempt to increase the resolution of the immune reaction analyzer by means of ultrasonic waves action on the reagent mixture in vitro is taken in this paper. The RBC agglutination reaction which is usually used for the blood group type examination is chosen as an example of an object of the investigation. Different laser optical trains of the devices based on the turbidimetric and nephelometric methods and their combination are analyzed here. The influence of the ultrasonic wave time interval action and of the features of the sample preparation procedure on the resolution towards the agglutination process was investigated in this work. It is shown that the ultrasonic wave action on the reagent mixture leads to a large gain in the resolution of the device towards the RBC agglutination process. The experiments showed that the resolution of the device was enough to register the agglutination process even for the erythrocytes with weak agglutination ability when the reaction was invisible without ultrasonic action. It occurred that the diagnostic test time was more than by an order shortened due to the ultrasonic wave action. The optimal ultrasonic time interval action, the sample preparation technology and experimental technique were defined. The principle of the ultrasonic wave action on the cells agglutination process suggested here can be spread out on the immune

  9. Modulation of ligand-mediated human red cell agglutinability by prostaglandins

    SciTech Connect

    McLawhon, R.W.; Marikovsky, Y.; Weinstein, R.S.

    1986-03-01

    Ethanol induces the transformation of human red cells from bioconcave discs to echinocytes in vitro. In addition, they have observed that ethanol can enhance the agglutination of red cells by the plant lectin wheat germ agglutinin or poly-L-lysine. Incubation of washed human red cells with 5 and 10% ethanol (v/v) in phosphate buffered saline, pH 7.3 at 25/sup 0/C produced a 30% increase in ligand-mediated agglutinability within 12 min. Simultaneous addition of ethanol and one of the following prostaglandin derivatives, PGE/sub 1/, pge/sub 2/, pgf/sub 2/-alpha, or PGl/sub 2/ (10/sup -9/ to 5 x 10/sup -7/ M) prevented the shape-associated increases in red cell agglutinability. Thromboxane-B/sub 2/ had no effect on agglutinability. Prostaglandins did not prevent ethanol-induced red cell shape transformations per se under identical experimental conditions. As intragastric administration of 100% ethanol results in the formation of spiculated red cell thrombi in postcapillary venules of rat gastric mucosa, they postulate that the cytoprotective role of prostanoids in preventing mucosal ulceration may be due in part to their capacity to inhibit intravascular ligand mediated red cell agglutination, hemostasis, and their sequelae, epithelial necrosis. Moreover, the data suggest that ethanol-induced red cell shape transformations and ligand-mediated agglutination represent two distinct and independent biological phenomena.

  10. Agglutination by anti-capsular polysaccharide antibody is associated with protection against experimental human pneumococcal carriage

    PubMed Central

    Reiné, J; Zangari, T; Owugha, JT; Pennington, SH; Gritzfeld, JF; Wright, AD; Collins, AM; van Selm, S; de Jonge, MI; Gordon, SB; Weiser, JN; Ferreira, DM

    2016-01-01

    The ability of pneumococcal conjugate vaccine (PCV) to decrease transmission by blocking the acquisition of colonization has been attributed to herd immunity. We describe the role of mucosal IgG to capsular polysaccharide (CPS) in mediating protection from carriage, translating our findings from a murine model to humans. We used a flow-cytometric assay to quantify antibody-mediated agglutination demonstrating that hyperimmune sera generated against an unencapsulated mutant was poorly agglutinating. Passive immunization with this antiserum was ineffective to block acquisition of colonization compared to agglutinating antisera raised against the encapsulated parent strain. In the human challenge model samples were collected from PCV and control vaccinated adults. In PCV-vaccinated subjects IgG levels to CPS were increased in serum and nasal wash (NW). IgG to the inoculated strain CPS dropped in NW samples after inoculation suggesting its sequestration by colonizing pneumococci. In post-vaccination NW samples pneumococci were heavily agglutinated compared to pre-vaccination samples in subjects protected against carriage. Our results indicate that pneumococcal agglutination mediated by CPS specific antibodies is a key mechanism of protection against acquisition of carriage. Capsule may be the only vaccine target that can elicit strong agglutinating antibody responses, leading to protection against carriage acquisition and generation of herd immunity. PMID:27579859

  11. In vitro neuronal cytotoxicity of latex and nonlatex orthodontic elastics.

    PubMed

    Hanson, Mark; Lobner, Doug

    2004-07-01

    Although the toxicity of many dental materials has been thoroughly investigated, the toxicity of orthodontic elastic materials has not been extensively tested. We evaluated the neurotoxicity of 3 latex and 3 nonlatex orthodontic elastics in murine cerebral cortical cell cultures. Standard-sized pieces of each material from 3 manufacturers (American, Masel, and GAC) were placed on culture well inserts, allowing the material to be exposed to the culture bathing media without causing physical disruption of the cells. Cell death was quantified by assaying the release of the cytosolic enzyme lactate dehydrogenase. Exposure of cortical cultures to the nonlatex elastics did not cause significant neuronal death, but exposure to each of the latex elastics resulted in significant neuronal death. The neuronal death induced by each of the latex elastics was blocked by adding the metal chelator, EDTA (calcium disodium ethylenediaminetetraacetate). Because many latexes use zinc-containing compounds in the prevulcanization process, and the death induced had characteristics similar to zinc-induced neuronal death, it seems likely that the toxicity of latex elastics was mediated by zinc release. Because ingestion of zinc is not a health risk, the results suggest that, in spite of the finding that latex elastics have higher in vitro cytotoxicity than nonlatex elastics, the use of latex elastics in orthodontics is acceptable.

  12. Latex samples for RAMSES electrophoresis experiment on IML 2

    NASA Technical Reports Server (NTRS)

    Seaman, Geoffrey V. F.; Knox, Robert J.

    1994-01-01

    The objectives of these reported studies were to provide ground based support services for the flight experiment team for the RAMSES experiment to be flown aboard IML-2. The specific areas of support included consultation on the performance of particle based electrophoresis studies, development of methods for the preparation of suitable samples for the flight hardware, the screening of particles to obtain suitable candidates for the flight experiment, and the electrophoretic characterization of sample particle preparations. The first phases of these studies were performed under this contract, while the follow on work was performed under grant number NAG8 1081, 'Preparation and Characterization of Latex Samples for RAMSES Experiment on IML 2.' During this first phase of the experiment the following benchmarks were achieved: Methods were tested for the concentration and resuspension of latex samples in the greater than 0.4 micron diameter range to provide moderately high solids content samples free of particle aggregation which interferred with the normal functioning of the RAMSES hardware. Various candidate latex preparations were screened and two candidate types of latex were identified for use in the flight experiments, carboxylate modified latex (CML) and acrylic acid-acrylamide modified latex (AAM). These latexes have relatively hydrophilic surfaces, are not prone to aggregate, and display sufficiently low electrophoretic mobilities in the flight buffer so that they can be used to make mixtures to test the resolving power of the flight hardware.

  13. Agglutinating mouse IgG3 compares favourably with IgMs in typing of the blood group B antigen: Functionality and stability studies

    PubMed Central

    Klaus, Tomasz; Bzowska, Monika; Kulesza, Małgorzata; Kabat, Agnieszka Martyna; Jemioła-Rzemińska, Małgorzata; Czaplicki, Dominik; Makuch, Krzysztof; Jucha, Jarosław; Karabasz, Alicja; Bereta, Joanna

    2016-01-01

    Mouse immunoglobulins M (IgMs) that recognize human blood group antigens induce haemagglutination and are used worldwide for diagnostic blood typing. Contrary to the current belief that IgGs are too small to simultaneously bind antigens on two different erythrocytes, we obtained agglutinating mouse IgG3 that recognized antigen B of the human ABO blood group system. Mouse IgG3 is an intriguing isotype that has the ability to form Fc-dependent oligomers. However, F(ab′)2 fragments of the IgG3 were sufficient to agglutinate type B red blood cells; therefore, IgG3-triggered agglutination did not require oligomerization. Molecular modelling indicated that mouse IgG3 has a larger range of Fab arms than other mouse IgG subclasses and that the unique properties of mouse IgG3 are likely due to the structure of its hinge region. With a focus on applications in diagnostics, we compared the stability of IgG3 and two IgMs in formulated blood typing reagents using an accelerated storage approach and differential scanning calorimetry. IgG3 was much more stable than IgMs. Interestingly, the rapid decrease in IgM activity was caused by aggregation of the molecules and a previously unknown posttranslational proteolytic processing of the μ heavy chain. Our data point to mouse IgG3 as a potent diagnostic tool. PMID:27484487

  14. Agglutinating mouse IgG3 compares favourably with IgMs in typing of the blood group B antigen: Functionality and stability studies.

    PubMed

    Klaus, Tomasz; Bzowska, Monika; Kulesza, Małgorzata; Kabat, Agnieszka Martyna; Jemioła-Rzemińska, Małgorzata; Czaplicki, Dominik; Makuch, Krzysztof; Jucha, Jarosław; Karabasz, Alicja; Bereta, Joanna

    2016-08-03

    Mouse immunoglobulins M (IgMs) that recognize human blood group antigens induce haemagglutination and are used worldwide for diagnostic blood typing. Contrary to the current belief that IgGs are too small to simultaneously bind antigens on two different erythrocytes, we obtained agglutinating mouse IgG3 that recognized antigen B of the human ABO blood group system. Mouse IgG3 is an intriguing isotype that has the ability to form Fc-dependent oligomers. However, F(ab')2 fragments of the IgG3 were sufficient to agglutinate type B red blood cells; therefore, IgG3-triggered agglutination did not require oligomerization. Molecular modelling indicated that mouse IgG3 has a larger range of Fab arms than other mouse IgG subclasses and that the unique properties of mouse IgG3 are likely due to the structure of its hinge region. With a focus on applications in diagnostics, we compared the stability of IgG3 and two IgMs in formulated blood typing reagents using an accelerated storage approach and differential scanning calorimetry. IgG3 was much more stable than IgMs. Interestingly, the rapid decrease in IgM activity was caused by aggregation of the molecules and a previously unknown posttranslational proteolytic processing of the μ heavy chain. Our data point to mouse IgG3 as a potent diagnostic tool.

  15. Size effects of latex nanomaterials on lung inflammation in mice

    SciTech Connect

    Inoue, Ken-ichiro Takano, Hirohisa; Yanagisawa, Rie; Koike, Eiko; Shimada, Akinori

    2009-01-01

    Effects of nano-sized materials (nanomaterials) on sensitive population have not been well elucidated. This study examined the effects of pulmonary exposure to (latex) nanomaterials on lung inflammation related to lipopolysaccharide (LPS) or allergen in mice, especially in terms of their size-dependency. In protocol 1, ICR male mice were divided into 8 experimental groups that intratracheally received a single exposure to vehicle, latex nanomaterials (250 {mu}g/animal) with three sizes (25, 50, and 100 nm), LPS (75 {mu}g/animal), or LPS plus latex nanomaterials. In protocol 2, ICR male mice were divided into 8 experimental groups that intratracheally received repeated exposure to vehicle, latex nanomaterials (100 {mu}g/animal), allergen (ovalbumin: OVA; 1 {mu}g/animal), or allergen plus latex nanomaterials. In protocol 1, latex nanomaterials with all sizes exacerbated lung inflammation elicited by LPS, showing an overall trend of amplified lung expressions of proinflammatory cytokines. Furthermore, LPS plus nanomaterials, especially with size less than 50 nm, significantly elevated circulatory levels of fibrinogen, macrophage chemoattractant protein-1, and keratinocyte-derived chemoattractant, and von Willebrand factor as compared with LPS alone. The enhancement tended overall to be greater with the smaller nanomaterials than with the larger ones. In protocol 2, latex nanomaterials with all sizes did not significantly enhance the pathophysiology of allergic asthma, characterized by eosinophilic lung inflammation and Igs production, although latex nanomaterials with less than 50 nm significantly induced/enhanced neutrophilic lung inflammation. These results suggest that latex nanomaterials differentially affect two types of (innate and adaptive immunity-dominant) lung inflammation.

  16. [Successful desensitization to latex by sublingual immunotherapy in a health worker].

    PubMed

    Bueno-De Sá, Adriano; Gaspar, Angela; Solé, Dirceu; Morais-Almeida, Mário

    2014-01-01

    Latex allergy is still a public health problem responsible for some occupational diseases tough to be treated without removing the patient from his/her workspace. For patients allergic to latex, sublingual immunotherapy (SLIT) for latex is a tool that can be very useful. We report the case of a nurse with latex allergy who underwent successful desensitization to latex by SLIT, and discuss about possible causes of the success of this therapy.

  17. Kinetics of Narrowly dispersed Latex Formation in a Surfactant-free Emulsion Polymerization of Styrene in Acetone-Water Mixture

    NASA Astrophysics Data System (ADS)

    Cheng, He; Li, Zhiyong; Han, Charles

    2012-02-01

    The kinetics of narrowly dispersed latex formation in a surfactant-free emulsion polymerization of styrene in acetone-water was studied by a combination of transmission electron microscopy and light scattering. The critical nuclei were experimentally observed and the formation of narrowly dispersed PS latex is proved to be originated from competitive growth kinetics. Spherical nuclei were regenerated via a microphase inversion of PS oligomer in 50% volume fraction acetone-water mixture at 70^oC. They follow a polydispersed log-normal distribution and the smallest nucleus with Rs 1.1nm is similar to critical nuclei. Note the spherical nuclei are not necessarily narrowly dispersed. Competitive growth kinetics makes smaller nuclei grow much faster than large nuclei in the subsequent polymerization process, resulting in narrowly dispersed PS latex. Two kinds of PS seed particles were added, separately, into two parallel surfactant-free emulsion polymerization batches of styrene in acetone-water mixture at 70^oC. It was found that the size of seed particles almost does not change, but the small size PS latex grows rapidly. Our fitting results proves competitive growth kinetics proposed by Vanderhoff and coworkers.

  18. Comparative Study on Plant Latex Particles and Latex Coagulation in Ficus benjamina, Campanula glomerata and Three Euphorbia species

    PubMed Central

    Bauer, Georg; Gorb, Stanislav N.; Klein, Marie-Christin; Nellesen, Anke; von Tapavicza, Max; Speck, Thomas

    2014-01-01

    Among latex-producing plants, mainly the latex of Hevea brasiliensis has been studied in detail so far, while comprehensive comparative studies of latex coagulation mechanisms among the more than 20,000 latex-bearing plant species are lacking. In order to give new insights into the potential variety of coagulation mechanisms, the untreated natural latices of five latex-bearing plants from the families Euphorbiaceae, Moraceae and Campanulaceae were visualised using Cryo-SEM and their particle size compared using the laser diffraction method. Additionally, the laticifers of these plants species were examined in planta via Cryo-SEM. Similar latex particle sizes and shape were found in Ficus benjamina and Hevea brasiliensis. Hence, and due to other similarities, we hypothesize comparable, mainly chemical, coagulation mechanisms in these two species, whereas a physical coagulation mechanism is proposed for the latex of Euphorbia spp. The latter mechanism is based on the huge amount of densely packed particles that after evaporation of water build a large surface area, which accelerates the coagulation procedure. PMID:25409036

  19. Comparative study on plant latex particles and latex coagulation in Ficus benjamina, Campanula glomerata and three Euphorbia species.

    PubMed

    Bauer, Georg; Gorb, Stanislav N; Klein, Marie-Christin; Nellesen, Anke; von Tapavicza, Max; Speck, Thomas

    2014-01-01

    Among latex-producing plants, mainly the latex of Hevea brasiliensis has been studied in detail so far, while comprehensive comparative studies of latex coagulation mechanisms among the more than 20,000 latex-bearing plant species are lacking. In order to give new insights into the potential variety of coagulation mechanisms, the untreated natural latices of five latex-bearing plants from the families Euphorbiaceae, Moraceae and Campanulaceae were visualised using Cryo-SEM and their particle size compared using the laser diffraction method. Additionally, the laticifers of these plants species were examined in planta via Cryo-SEM. Similar latex particle sizes and shape were found in Ficus benjamina and Hevea brasiliensis. Hence, and due to other similarities, we hypothesize comparable, mainly chemical, coagulation mechanisms in these two species, whereas a physical coagulation mechanism is proposed for the latex of Euphorbia spp. The latter mechanism is based on the huge amount of densely packed particles that after evaporation of water build a large surface area, which accelerates the coagulation procedure.

  20. Current prevalence rate of latex allergy: Why it remains a problem?

    PubMed Central

    Wu, Miaozong; McIntosh, James; Liu, Jian

    2016-01-01

    Objectives: This article aims to review the current prevalence rate of latex allergy among healthcare workers, susceptible patients, and the general public, and to investigate why latex is still a ubiquitous occupational health hazard. Methods: Scientific publications on PubMed, particularly those published within the last five years, and current regulations from agencies such as Food and Drug Administration (FDA) were reviewed. Consumer and commercial products that may contain latex were also surveyed. Results: Approximately 12 million tons of natural rubber latex is produced annually and is widely used to manufacture millions of consumer and commercial products. Only limited number of latex-derived products have been approved and regulated by government agencies, such as FDA, whereas the majority of finished products do not label whether they contain latex. Owing to millions of unidentifiable products containing latex and many routes for exposure to latex, preventing contact with latex allergens and reducing the prevalence of latex allergy are more difficult than expected. Reported data suggest that the average prevalence of latex allergy worldwide remains 9.7%, 7.2%, and 4.3% among healthcare workers, susceptible patients, and general population, respectively. Conclusions: Latex-derived products are ubiquitous, and latex allergy remains a highly prevalent health risk in many occupations and to the general population. Developing alternative materials and increasing the ability to identify and label latex-derived products will be practicable approaches to effectively control the health risks associated with latex. PMID:27010091

  1. Cementing multilateral wells with latex cement

    SciTech Connect

    1997-08-01

    A multilateral well is a well with one or more branches or lateral sections extending from its main wellbore. The laterals can be openhole or cased hole. When laterals are cased hole, the cement integrity for casing support and zonal isolation is very important. When cementing the lateral sections of multilateral wells, it is important to use a cement with high strength and durability to support the liner throughout the life of the well and to support the lateral section. The cement column is subjected to various stresses when the cemented inner stub is cut. High tensile strength, flexural strength, and crack resistance are required. These properties are necessary to make a clean cut through the cement sheath that does not induce cracks in the cement column. Latex cement is commonly used for its gas-migration-control property.

  2. Epoxy coatings over latex block fillers

    SciTech Connect

    Vincent, L.D.

    1997-12-01

    Failures of polymerized epoxy coatings applied over latex/acrylic block fillers continue to plague owners of commercial buildings, particularly those with high architectural content such as condominiums, high rise offices, etc. Water treatment facilities in paper mills are especially prone to this problem. The types of failures include delamination of the topcoats, blisters in both the block fillers and the topcoats and disintegration of the block filler itself. While the problem is well known, the approach to a solution is not. A study of several coatings manufacturer`s Product Data Sheets shows a wide variance in the recommendations for what are purportedly generically equivalent block fillers. While one manufacturer might take an essentially architectural approach, another will take a heavy-duty industrial approach. To the specifying architect or engineer who has little training in the complexities of protective coating systems, this presents a dilemma. Who does he believe? What does he specify? To whom can he turn for independent advice?

  3. Prevalence of type I allergy to natural rubber latex and type IV allergy to latex and rubber additives in operating room staff with glove-related symptoms.

    PubMed

    Miri, Sara; Pourpak, Zahra; Zarinara, Alireza; Zarinara, Alam; Heidarzade, Marzieh; Kazemnejad, Anoushirvan; Kardar, Gholamali; Firooz, Alireza; Moin, Athar

    2007-01-01

    There is lack of data on the prevalence of latex allergy in the health care setting in Iran. This study was performed to determine the prevalence of type I latex allergy and type IV allergy to latex and rubber additives among the operating room staff with glove-related symptoms in 13 general hospitals in Tehran. Skin-prick tests with commercial latex extract, patch tests with latex and 25 rubber additive series, and total and latex-specific IgE detection were performed on the operating room staff who reported latex glove-related symptoms. Five hundred twelve self-administered questionnaires (100%) were completed by all operating room staff and latex glove-related symptoms were reported by 59 (11.5%) employees. Among all symptomatic operating room staff tested, the prevalence of type I latex allergy was 30.5% and the prevalence rates of type IV allergy to latex and rubber additives were 16.7 and 14.6%, respectively. The most positive patch test result with rubber additives was related to tetramethylthiuram monosulfide (38.5%). The risk factors for type I latex allergy were female sex (p = 0.009) and positive patch test with rubber additives (p = 0.012). Subjects who had positive patch test with latex were significantly more likely to have positive patch test with rubber additives (p < 0.0001). Our results showed a high prevalence of type I latex allergy and type IV allergy to latex and rubber additives. Based on this study, we recommend eliminating powdered latex gloves from the operating rooms of the 13 studied general hospitals and support the substitution of powder-free latex gloves.

  4. Phorbic Acid Biosynthesis in the Latex Vessel System of Euphorbia

    PubMed Central

    Nordal, Arnold; Benson, A. A.

    1969-01-01

    Evidence is presented that phorbic acid is formed in the latex producing cell system, rather than in photosynthetic or chlorophyll-free tissues of Euphorbia resinifera Berg. When a branch of the plant was kept first in a 14CO2 atmosphere with 12 hr light-dark periods for 2 days and then left under natural conditions in the air outside for at least 2 to 3 days, radioactive phorbic acid was found in the latex. Phorbic acid synthesis appeared to be independent of the photosynthetic and respiratory activities of the plant. Besides phorbic acid 2 other major radioactive compounds were recognized in the latex, a glycoside or oligosaccharide, and a lipid belonging to the group of triterpenoid compounds characteristic of the latex in several species of Euphorbia. Images PMID:16657036

  5. [Allergic reactions caused by latex: warning to health workers].

    PubMed

    Lopes, R A; Lopes, M H

    1999-01-01

    In this study, a bibliographic survey is made of all articles, published during the last few years, dealing with allergic reactions to latex. The first article on allergic reactions associated with latex was published in Britain, in 1979. Since then, the number of cases reported have increased (Barton, 1993). Type I allergic reaction (immediate reaction) and Type IV (delayed reaction) are part of the latex allergic process (Steelman, 1995). Contact allergy is due to inadequate washing during manufacture, which results in the retention of water-soluble proteins that cause allergic reactions in susceptible people. A wide variety of allergic reactions that vary from contact dermatitis to anaphylatic shock are described in literature. These finding show that a health team must know the probable implications of latex allergy.

  6. Corrosion inhibition of reinforcing steel by using acrylic latex

    SciTech Connect

    Wang, S.X.; Lin, W.W.; Ceng, S.A.; Zhang, J.Q.

    1998-05-01

    Acrylic latex was introduced into steel-reinforcing steel concrete as concrete admixtures or rebar coatings in order to prevent corrosion of steel reinforcements. The results showed that applying the latex by both methods took effect in different ways, while the latter was more noticeable. The corrosion prevention mechanism and the surface state of the steel rebar were also explored, based on which suggestions for enhancing the corrosion-resistant ability were made.

  7. Immune response modulation by curcumin in a latex allergy model

    PubMed Central

    Kurup, Viswanath P; Barrios, Christy S; Raju, Raghavan; Johnson, Bryon D; Levy, Michael B; Fink, Jordan N

    2007-01-01

    Background There has been a worldwide increase in allergy and asthma over the last few decades, particularly in industrially developed nations. This resulted in a renewed interest to understand the pathogenesis of allergy in recent years. The progress made in the pathogenesis of allergic disease has led to the exploration of novel alternative therapies, which include herbal medicines as well. Curcumin, present in turmeric, a frequently used spice in Asia has been shown to have anti-allergic and inflammatory potential. Methods We used a murine model of latex allergy to investigate the role of curcumin as an immunomodulator. BALB/c mice were exposed to latex allergens and developed latex allergy with a Th2 type of immune response. These animals were treated with curcumin and the immunological and inflammatory responses were evaluated. Results Animals exposed to latex showed enhanced serum IgE, latex specific IgG1, IL-4, IL-5, IL-13, eosinophils and inflammation in the lungs. Intragastric treatment of latex-sensitized mice with curcumin demonstrated a diminished Th2 response with a concurrent reduction in lung inflammation. Eosinophilia in curcumin-treated mice was markedly reduced, co-stimulatory molecule expression (CD80, CD86, and OX40L) on antigen-presenting cells was decreased, and expression of MMP-9, OAT, and TSLP genes was also attenuated. Conclusion These results suggest that curcumin has potential therapeutic value for controlling allergic responses resulting from exposure to allergens. PMID:17254346

  8. [Latex proteins as the trigger of respiratory and systemic allergies].

    PubMed

    Baur, X; Jäger, D; Engelke, T; Rennert, S; Czuppon, A B

    1992-08-21

    56 patients (52 members of the hospital's staff, four with other employment) who had hypersensitivity reactions to latex articles and developed an immediate-type response to latex extract with the skin-prick test were studied. Specific IgE antibodies were present in the enzyme-allergo-sorbent test of 50 of the subjects. Latex-containing surgical and household gloves were the main cause of allergies. Patients with isolated contact urticaria (n = 8) had a tendency towards lower antibody concentrations than those with additional respiratory and/or systemic symptoms (n = 48). Occupation-related provocation tests triggered rhinitis in 19, conjunctivitis in ten, and bronchial obstruction in six. The main allergen was found to be a protein with a relative molecular mass of 58,000, originating from the latex milk and passing from the latex glove into the glove powder. In the course of usual activities considerable allergen inhalation can occur. Even small amounts (e.g. 400 ng/ml) can precipitate significant allergic reactions. The results show that the main latex allergen, a glycine-rich protein molecule, can cause cutaneous, inhalant and systemic hypersensitivity reactions.

  9. The durability of silicone versus latex mock arteries.

    PubMed

    Conti, J C; Strope, E R; Goldenberg, L M; Price, K S

    2001-01-01

    Latex mock arteries used in medical device testing allow researchers to evaluate mechanical characteristics of intravascular medical products without using animal or human clinical studies for this data. Such intravascular situations include determining properties such as drag and steerability of catheters, recoil of vascular stents, and clinician training. In fatigue testing, the latex mock arteries are used to receive deployed products and are then repeatedly pressurized at biologically relevant pressures to determine the long term durability of the product. By matching dimensions and pressure-volume relationships (compliance) of these latex tubes, researchers have a reliable means to evaluate and predict product lifetimes. The problem with latex mock arteries is two-fold: First, they are opaque so the product inside the artery cannot be seen during evaluation of the integrity of the product or during clinical training sessions. Second, latex tubes fatigue; therefore, the loading that they place on the internalized products varies with time. During long term durability studies, latex tubes may have to be replaced as often as every 100 million cycles. This can be problematic with products that are difficult to redeploy. We have developed a clear silicone mock artery system that allows us to fabricate three-dimensional objects, including tubes with precise geometric and mechanical properties. Our evaluations show that the mock arteries can be stressed up to 400 million cycles with little or no change in mechanical properties. We are in the process of continuing evaluations to determine long term durability.

  10. Safety of latex urinary catheters for the short time drainage

    PubMed Central

    Hosseinpour, Mehrdad; Noori, Saeed; Amir-Beigi, Mahdieh; Pourfakharan, Mohammad Hassan; Ehteram, Hassan; Hamsayeh, Mohadese

    2014-01-01

    Background: In this study, we attempt to identify the most appropriate catheter (silicone vs. latex) for short-term urinary catheterization. We compared the post-operative clinico-pathological complications between latex and silicone for short term catheterization in rabbits with hypospadias. Materials and Methods: Forty rabbits were used in our study to compare complications of catheterization. They were divided in two groups. Hypospadias like defect was created by a 1 cm long excision of the ventral urethra. For urethroplasty, we used tubularized incised plate technique. Latex and silicon catheters were used in groups 1 and 2, respectively. Post-operatively, routine laboratory urine test and complications (allergy, infection, bleeding) were compared in groups. Results: A total of 40 rabbits underwent hypospadias repair. Findings showed that there were no significant differences between groups based on urine test indices (P = NS). Urinary tract infection rate was 10% (2 rabbits) in latex and 0% in silicone groups (P = NS). There were no significant differences between groups regarding of cystitis grades between study groups (P = NS). Conclusion: It seems that urinary tract catheterization with latex catheters is a safe, feasible, and in-expensive procedure for short-term post-operative course in hypospadias surgery in patients without latex hypersensitivity. PMID:25125890

  11. Troubleshooting for the observed problems in processing latex concentrate from natural resource

    NASA Astrophysics Data System (ADS)

    Afreen, S.; Haque, K. R.; Huda, M. K.

    2013-06-01

    Natural latex has special importance in the rubber industry for manufacturing different types of goods like gloves, balloons, male contraceptive and similar thin walled articles. This natural latex is much more sensitive a liquid to handle since it can easily become contaminated and thereby coagulated which makes it unfavourable for centrifuge and getting concentrate from it. Some other related measures also are included in consideration during the processing of concentrate latex from the natural raw latex. The problems that are being faced in a concentrate latex processing plant can be categorized in different groups like, problems related to the latex property, mechanical problems, electrical problems, handling and storage problems, transformation problems, problems related to environmental issues, etc. Among them, the most common and vital problems frequently observed in a concentrate latex processing plant are discussed here with a view to finding the measures for solution which will help to maintain the latex property in any latex processing plant.

  12. Hevea latex lectin binding protein in C-serum as an anti-latex coagulating factor and its role in a proposed new model for latex coagulation.

    PubMed

    Wititsuwannakul, Rapepun; Pasitkul, Piyaporn; Jewtragoon, Pattavuth; Wititsuwannakul, Dhirayos

    2008-02-01

    A distinct protein specifically recognized by its strong interaction with Hevea latex lectin (HLL) was detected in the aqueous C-serum fraction of centrifuged fresh latex. This C-serum lectin binding protein (CS-HLLBP) exhibited strong inhibition of HLL-induced hemagglutination. The CS-HLLBP was purified to homogeneity by a protocol that included ammonium sulfate fractionation, size exclusion and ion exchange chromatography. The purified CS-HLLBP had a specific HI titer of 0.23microg ml(-1). Its M(r)s analyzed by SDS-PAGE was ca. 40kDa and that by gel filtration was ca. 204kDa. It has a pI value of 4.7, an optimum activity between pH 6 and10 and was heat stable up to 50 degrees C. The HI activity of CS-HLLBP was abolished upon treatment with chitinase. The CS-HLLBP inhibited HLL-induced rubber particle aggregation in a dose dependent manner. A highly positive correlation between CS-HLLBP activity and rubber yield per tapping was found. The correlations for fresh latex (r=0.98, P<0.01) and dry rubber (r=0.95, P<0.01) were both highly significant. This indicated that the CS-HLLBP might be used as a reliable marker for the mass screening of young seedlings to identify and select clones with potential to be superior producers of rubber. A latex anti-coagulating role of the CS-HLLBP is proposed. The findings described in this 3 paper series have been used to propose a new model of rubber latex coagulation that logically describes roles for the newly characterized latex lectin and the two lectin binding proteins.

  13. Traces of dissolved particles, including coccoliths, in the tests of agglutinated foraminifera from the Challenger Deep (10,897 m water depth, western equatorial Pacific)

    NASA Astrophysics Data System (ADS)

    Gooday, A. J.; Uematsu, K.; Kitazato, H.; Toyofuku, T.; Young, J. R.

    2010-02-01

    surfaces and no obvious intervening cement. Our observations suggest that (1) small biogenic particles can reach the deepest parts of the ocean intact in rapidly sinking phytodetrital aggregates or faecal pellets and (2) some agglutinated foraminifera living at extreme hadal depths construct a test from biogenic or detrital particles, which subsequently dissolve, leaving imprints and other remnants in the organic matrix of the test.

  14. Synthesis and engineering of polymeric latex particles for medical applications

    NASA Astrophysics Data System (ADS)

    Kim, Sangyup

    Latex particles with well-defined colloidal and surface characteristics have received increasing attention due to their useful applications in many areas, especially as solid phase supports in numerous biological applications such as immunoassay, DNA diagnostic, cell separation, and drug delivery carrier. Hemodialysis membrane using these particles would be another potential application for the advanced separation treatment for patients with end stage renal disease (ESRD). It is desirable to remove middle molecular weight proteins with minimal removal of other proteins such as albumin. Thus, it is necessary to understand the fundamental interactions between the particles and blood proteins to maximize the performance of these membranes. This improvement will have significant economic and health impact. The objective of this study is to synthesize polymeric latex particles of specific functionality to achieve the desired selective separation of target proteins from the human blood. Semi-continuous seed emulsion polymerization was used to prepare monodisperse polystyrene seed particles ranging from 126+/-7.5 to 216+/-5.3 nm in size, which are then enlarged by about 800nm. Surfactant amount played a key role in controlling the latex particle size. Negatively charged latex particles with a different hydrophobicity were prepared by introduction of a sodium persulfate initiator and hydrophilic acrylic acid monomer. The prepared polymeric particles include bare polystyrene (PS) particles, less hydrophobic PS core and PMMA shell particles, and more hydrophilic PS core and PMMA-co-PAA shell latex particles with a 370nm mean diameter. SEM, light scattering, and zeta potential measurements were used to characterize particle size and surface properties. Adsorption isotherms of two proteins, bovine serum albumin (BSA) and beta2-microglobulin (beta2M), on latex particles were obtained as a function of pH and ionic strength using the bicinchoninic acid (BCA) assay method. The

  15. Helicobacter pylori TlyA agglutinates liposomes and induces fusion and permeabilization of the liposome membranes.

    PubMed

    Lata, Kusum; Chattopadhyay, Kausik

    2014-06-10

    Helicobacter pylori TlyA is a pore-forming hemolysin with potent cytotoxic activity. To explore the potential membrane-damaging activity of H. pylori TlyA, we have studied its interaction with the synthetic liposome vesicles. In our study, H. pylori TlyA shows a prominent ability to associate with the liposome vesicles without displaying an obligatory requirement for any protein receptor on the liposome membranes. Interaction of TlyA triggers agglutination of the liposome vesicles. Such agglutinating activity of TlyA could also be observed with erythrocytes before the induction of its pore-forming hemolytic activity. In addition to its agglutinating activity against liposomes, TlyA also induces fusion and disruption of the liposome membranes. Altogether, our study highlights novel membrane-damaging properties of H. pylori TlyA that have not been documented previously with any other TlyA family protein.

  16. Evaluation of the usefulness of six commercial agglutination assays for serologic diagnosis of toxoplasmosis.

    PubMed

    Villard, Odile; Cimon, Bernard; Franck, Jacqueline; Fricker-Hidalgo, Hélène; Godineau, Nadine; Houze, Sandrine; Paris, Luc; Pelloux, Hervé; Villena, Isabelle; Candolfi, Ermanno

    2012-07-01

    Six agglutination tests for detecting Toxoplasma gondii-specific antibodies (immunoglobulin G or M) in serum were performed and compared. In total, 599 sera were examined using direct and indirect agglutination assays. Sensitivity varied from 93.7% to 100% and specificity from 97.1% to 99.2%. In a selected population with interfering diseases, the percentage of false positives ranged from 4.3% to 10.9%. Although an overall agreement of 100% was found for chronic toxoplasmosis, sensitivity for the detection of confirmed acute toxoplasmosis ranged from 86.4% to 97.3%. Regarding the large variability in terms of the performance of the 6 assays, tests based on the hemagglutination principle were found to be better than the other agglutination tests for all the panels evaluated, meaning that they could be used as qualitative or semiquantitative low-cost screening assays.

  17. Evaluation of the one-point microcapsule agglutination test for diagnosis of leptospirosis.

    PubMed Central

    Arimitsu, Y.; Kmety, E.; Ananyina, Y.; Baranton, G.; Ferguson, I. R.; Smythe, L.; Terpstra, W. J.

    1994-01-01

    We have developed a one-point microcapsule agglutination test (MCAT) for the serodiagnosis of leptospirosis. The MCAT kit was evaluated for use in humans by six WHO Collaborating Centres for Reference and Research on Leptospirosis. The laboratories classified their serum samples on the basis of the microscopic agglutination test (MAT) and the following screening tests: enzyme-linked immunosorbent assay (ELISA), macroscopic (slide) agglutination test, or the complement fixation test. The MCAT may in some instances give a positive result earlier in the course of the disease than MAT or the ELISA IgM; on the other hand, it did not detect antibodies against some serovars, for example, those of the Sejroe or Australis serogroup in Slovakia. In contrast, however, the MCAT detected antibodies to serovar hardjo (the same serogroup as Sejroe) in patients from the United Kingdom and the Russian Federation. PMID:8062397

  18. SUPPRESSION OF BLOOD GROUP AGGLUTINABILITY OF HUMAN ERYTHROCYTES BY CERTAIN BACTERIAL POLYSACCHARIDES

    PubMed Central

    Ceppellini, Ruggero; Landy, Maurice

    1963-01-01

    Erythrocytes coated with bacterial capsular polysaccharides, notably the Vi antigen, were no longer agglutinated by antibodies directed against the various antigens native to the red cell surface. These effects could not be attributed to prevention of antibody uptake even though in some systems the uptake of antibody was diminished. In fact, agglutination by Rh-incomplete antibody was brought back to the original titer only after the sensitized Vi-coated cells had been subjected to ten alternating exposures to globulin and antiglobulin. Hemagglutination by Newcastle, mumps, and influenza viruses was also suppressed. Erythrocytes coated with Vi polysaccharide assumed the distinctive physicochemical attributes of this acidic polymer which results in a stabilization of the erythrocyte suspension as manifested by increased electrophoretic mobility and a striking decrease in the rate of sedimentation. Among the possible models for explaining the nature of the Vi effect on immune agglutination, the data favor interference with lattice formation. PMID:14019651

  19. Combined albumin and bicarbonate induces head-to-head sperm agglutination which physically prevents equine sperm-oviduct binding.

    PubMed

    Leemans, Bart; Gadella, Bart M; Stout, Tom A E; Sostaric, Edita; De Schauwer, Catharina; Nelis, Hilde; Hoogewijs, Maarten; Van Soom, Ann

    2016-04-01

    In many species, sperm binding to oviduct epithelium is believed to be an essential step in generating a highly fertile capacitated sperm population primed for fertilization. In several mammalian species, this interaction is based on carbohydrate-lectin recognition. D-galactose has previously been characterized as a key molecule that facilitates sperm-oviduct binding in the horse. We used oviduct explant and oviduct apical plasma membrane (APM) assays to investigate the effects of various carbohydrates; glycosaminoglycans; lectins; S-S reductants; and the capacitating factors albumin, Ca(2+) and HCO3(-) on sperm-oviduct binding in the horse. Carbohydrate-specific lectin staining indicated that N-acetylgalactosamine, N-acetylneuraminic acid (sialic acid) and D-mannose or D-glucose were the most abundant carbohydrates on equine oviduct epithelia, whereas D-galactose moieties were not detected. However, in a competitive binding assay, sperm-oviduct binding density was not influenced by any tested carbohydrates, glycosaminoglycans, lectins or D-penicillamine, nor did the glycosaminoglycans induce sperm tail-associated protein tyrosine phosphorylation. Furthermore, N-glycosidase F (PNGase) pretreatment of oviduct explants and APM did not alter sperm-oviduct binding density. By contrast, a combination of the sperm-capacitating factors albumin and HCO3(-) severely reduced (>10-fold) equine sperm-oviduct binding density by inducing rapid head-to-head agglutination, both of which events were independent of Ca(2+) and an elevated pH (7.9). Conversely, neither albumin and HCO3(-) nor any other capacitating factor could induce release of oviduct-bound sperm. In conclusion, a combination of albumin and HCO3(-) markedly induced sperm head-to-head agglutination which physically prevented stallion sperm to bind to oviduct epithelium.

  20. Overall evaluation of an immunological latex agglutination system for fecal occult blood testing in the colorectal cancer screening program of Florence.

    PubMed

    Rubeca, Tiziana; Peruzzi, Benedetta; Confortini, Massimo; Rapi, Stefano

    2012-10-08

    Several immunological fecal occult blood tests (FOBT) are currently available for colorectal cancer (CRC) screening. We compared the HM Jack (Jack) (Kiowa, Japan), with the OC-Hemodia (OC) (Eiken, Japan) in use in the Florence screening program. Aims of the study were: (i) to investigate the diagnostic performance and the best cutoff value for Jack; (ii) to evaluate the handiness of sampling tubes; (iii) to compare costs. A total of 5,044 subjects were screened with both tests. Sampling tube investigation was performed running each sample on both instruments. A number of 352 subjects positive for at least one test (175 OC, 310 Jack) were selected for further investigations, while 46 subjects refused further assessments. Analysis of costs related to the assessment phase was performed on the basis of Tuscany region's fares. Amongst the 306 subjects investigated, 9 CRC and 67 advanced adenomas (AdA) were detected. Detection rates (DR) were 1.4‰ for CRC and 9.6‰ for AdA. After Jack cutoff optimization, DR for CRC+AdA resulted in 11.1‰ for OC and 13.3‰ for Jack (p=0.041). Sensitivity of the methods was 73.7 for OC and 88.2 for Jack; specificity was 97.6 for OC and 96.0 for Jack, resulting in an increase of the required assessments from 3.5% to 5.1%. No differences were observed between sampling methods. Despite the lower specificity of Jack, its greater sensitivity makes the method attractive for screening programs. An increase of the costs of 30% for every subject investigated for pathological lesion (CRC+AdA) may be thus foreseen.

  1. Latex medical gloves: time for a reappraisal.

    PubMed

    Palosuo, Timo; Antoniadou, Irini; Gottrup, Finn; Phillips, Peter

    2011-01-01

    Many hospitals have implemented policies to restrict or ban the use of devices made of natural rubber latex (NRL) in healthcare as precautionary measures against the perceived risk of NRL allergy. Changes in glove technology, progress in measuring the specific allergenic potential of gloves and a dramatic decrease in the prevalence of NRL allergies after interventions and education prompted us to revisit the basis for justifiable glove selection policies. The published Anglophone literature from 1990 to 2010 was reviewed for original articles and reviews dealing with the barrier and performance properties of NRL and synthetic gloves and the role of glove powder. The review shows that NRL medical gloves, when compared with synthetic gloves, tend to be stronger, more flexible and better accepted by clinicians. The introduction of powder-free gloves has been associated with reductions in protein content and associated allergies. Recently, new methods to quantify clinically relevant NRL allergens have enabled the identification of gloves with low allergenic potential. The use of low-protein, low-allergenic, powder-free gloves is associated with a significant decrease in the prevalence of type I allergic reactions to NRL among healthcare workers. Given the excellent barrier properties and operating characteristics, dramatically reduced incidences of allergic reactions, availability of specific tests for selection of low-allergen gloves, competitive costs and low environmental impact, the use of NRL gloves within the hospital environment warrants reappraisal.

  2. Agglutinates as recorders of fossil soil compositions. [of Apollo 17 lunar probes

    NASA Technical Reports Server (NTRS)

    Taylor, G. J.; Wentworth, S.; Warner, R. D.; Keil, K.

    1978-01-01

    The composition of agglutinates in polished sections of the Apollo 17 drill core was studied in an attempt to deduce the nature of the Taurus-Littrow valley regolith prior to the formation of the Camelot and Central Cluster craters. The agglutinate compositions in the soils differed from the host soil compositions except for samples from the North Massif. Local materials from the valley floor and the massifs appear to form the pre-Central Cluster regolith. It is also shown that chemical mixing models for bulk soil compositions can be misleading unless the petrologic characteristics of each soil are taken into account.

  3. [Relationship between the sensitivity of the delayed agglutination test and synthetic detergents].

    PubMed

    Iovchev, E; Vodas, K

    1977-01-01

    Residual amounts of detergents (Losk, Bio-73, Alka-lux, Bourgas, Bourgaslux, and Vero) in a concentration of 10-5 to 10-7 in physiologic saline can inhibit the agglutination titers by 3 to 5 degrees. This could mislead in the assessment of the reaction with regard to its diagnostic value. It is admitted that the inhibition produced is due to changes in the antibodies--drop in the total protein and light variations in all protein fractions as well as in the probable surface deterioration of the antigen, leading to its defective agglutinability. It is suggested to rinse more than five times all glassware that has been cleaned with detergents.

  4. Extraction and characterization of latex and natural rubber from rubber-bearing plants.

    PubMed

    Buranov, Anvar U; Elmuradov, Burkhon J

    2010-01-27

    Consecutive extraction of latex and natural rubber from the roots of rubber-bearing plants such as Taraxacum kok-saghyz (TKS), Scorzonera tau-saghyz (STS), and Scorzonera Uzbekistanica (SU) were carried out. Latex extraction was carried via two methods: Blender method and Flow method. The results of latex extraction were compared. Cultivated rubber-bearing plants contained slightly higher latex contents compared to those from wild fields. Several creaming agents for latex extraction were compared. About 50% of total natural rubber was extracted as latex. The results of the comparative studies indicated that optimum latex extraction can be achieved with Flow method. The purity of latex extracted by Blender method ( approximately 75%) was significantly lower than that extracted by Flow method (99.5%). When the latex particles were stabilized with casein, the latex was concentrated significantly. Through concentrating latex by flotation, the latex concentration of 35% was obtained. Bagasse contained mostly solid natural rubber. The remaining natural rubber in the bagasse (left after the latex extraction) was extracted using sequential solvent extraction first with acetone and then with several nonpolar solvents. Solid natural rubber was analyzed for gel content and characterized by size exclusion chromatography (SEC) for molecular weight determinations. SEC of solid natural rubber has shown that the molecular weight is about 1.8E6 and they contain less gel compared to TSR20 (Grade 20 Technically Specified Rubber), a commercial natural rubber from Hevea brasiliensis.

  5. Latex-less opium poppy: cause for less latex and reduced peduncle strength.

    PubMed

    Chaturvedi, Nidarshana; Singh, Sharad K; Shukla, Ashutosh K; Lal, Raj K; Gupta, Madan M; Dwivedi, Upendra N; Shasany, Ajit K

    2014-03-01

    A genotype 'Sujata' developed earlier at CSIR-CIMAP from its parent 'Sampada' is considered to be the latex-less variety of Papaver somniferum. These two genotypes are contrasting in terms of latex and stem strength. Earlier we have carried out microarray analysis to identify differentially expressing genes from the capsules of the two genotypes. In this study, the peduncles of the two genotypes were compared for the anatomy revealing less number of laticifers in the cortex and vascular bundles. One of the important cell wall-related genes (for laccase) from the microarray analysis showing significantly higher expression in 'Sampada' capsule was taken up for further characterization in the peduncle here. It was functionally characterized through transient overexpression and RNAi suppression in 'Sujata' and 'Sampada'. The increase in acid insoluble lignin and total lignin in overexpressed tissue of 'Sujata', and comparable decrease in suppressed tissue of 'Sampada', along with corresponding increase and decrease in the transcript abundance of laccase confirm the involvement of laccase in lignin biosynthesis. Negligible transcript in phloem compared to the xylem tissue localized its expression in xylem tissue. This demonstrates the involvement of P. somniferum laccase in lignin biosynthesis of xylem, providing strength to the peduncle/stem and preventing lodging.

  6. [Latex allergy and cross-reactions: a new threat?].

    PubMed

    Stevens, W

    2000-01-01

    Allergy to latex proteins has become an important problem, especially in the medical profession, but also in people who have regularly contact with latex products. The responsible antigens are proteins, which are present in the natural rubber latex (NRL), extracted from Hevea brasiliensis. These proteins are important in the synthesis of rubber and in the defence of the plant against external noxes (pathogenesis related proteins). Life threathening reactions occur more frequently in the operating theatre. Sensitisation can occur via different routes (aerogen, skin, parenteral, ...) but aerogenic sensitisation seems to be very important. Starch particles are important vectors of the antigens. Diagnosis is made via history, confirmed by demonstration of specific IgE via skin test (in vivo) or via an in vitro method (e.g. CAP, ELISA). Immunological cross reactions are very frequent with other plant or fruit allergens but cross allergy is less frequent (sensitivity and specificity of the in vitro test varies considerably depending on the nature of the fruit or vegetable investigated). There is also a cross reactivity with Ficus. Prevention with latex allergens becomes primordial in hospital settings. The industry is aware of the problem and produces more and more synthetic latex products.

  7. Extracellular calcium is involved in egg yolk-induced head-to-head agglutination of bull sperm.

    PubMed

    Yang, D H; McMillan, A G; Standley, N T; Shannon, P; Xu, Z Z

    2012-10-15

    Head-to-head agglutination of bull sperm occurs when semen is highly diluted in an egg yolk-citrate diluent without streptomycin. The objectives were to investigate causes of sperm agglutination and the underlying mechanism. Aliquots of bull semen were diluted in a base diluent (BD) supplemented with various test components and the percentage of agglutinated sperm (% AggSp) was quantified at 1, 5, 24, 48, and 72 h of incubation. When sperm were incubated at 22 °C, no agglutination was observed in BD for up to 72 h, whereas the % AggSp was 5.0, 41.7, 72.2, 91.1, and 92.8% in BD + 5% egg yolk (BD + EY) at 1, 5, 24, 48 and 72 h, respectively. However, no sperm agglutination was observed in BD + EY if incubation temperature was 37 °C. Addition of 5 or 10 mM ethylenebis (oxyethyleneni-trilo) tetra-acetic acid to BD + EY reduced the % AggSp from 95% to <5% at 72 h (P < 0.001), but addition of 5 mM CaCl(2) to BD failed to induce sperm agglutination in the absence of egg yolk, implicating calcium and other factors in egg yolk. Addition of the citrate-soluble fraction (CSF) of egg yolk to BD induced sperm agglutination similar to whole egg yolk, whereas water- and saline-soluble fractions of egg yolk were ineffective. The sperm-agglutinating efficacy of CSF (the % AggSp = 95% at 72 h) was reduced by dialysis (20%; P < 0.05), partially restored by addition of 5 mM CaCl2 (70%; P < 0.05), but the calcium effect was neutralized by addition of 5 mM ethylenebis (oxyethyleneni-trilo) tetra-acetic acid (1.7%; P < 0.05), again implicating calcium. Addition of 30 μM of a protein kinase A inhibitor (H-89) to an agglutinating diluent failed to inhibit sperm agglutination, whereas addition of 2 mM of a cAMP analogue, dbcAMP, to a nonagglutinating diluent failed to induce sperm agglutination. Agglutination status had no effect on sperm plasma membrane/acrosome status and mitochondrial membrane potential. In conclusion, calcium and other component(s) in the CSF of egg yolk induced head

  8. Single agglutinates: A comparative study of compositions of agglutinitic glass, whole-grain, bulk soil, and FMR

    NASA Technical Reports Server (NTRS)

    Basu, A.; Robinson, R.; Mckay, D. S.; Blanchard, D. P.; Morris, R. V.; Wentworth, Susan J.

    1994-01-01

    Previous workers on single agglutinates have variously interpreted the composition of agglutinitic glass to represent impact melts of (1) bulk soil, (2) mixed components in finer sizes, and (3) microtargets. Separately, Papike has argued in favor of fusion of the finest fraction of bulk soils. Thirty-four single agglutinates were hand-picked from the mature Apollo 16 soil 61181 (I(sub s)/FeO = 82) and the FMR and chemical composition (INAA for Fe, Sc, Sm, Co, Ni, and Cr) of each agglutinate particle were measured. Thirteen of these single agglutinates were selected for electron beam microanalysis and imaging. Less than 1 micron spots were analyzed (for Na, Mg, Al, Si, P, S, K, Ca, Ti, Cr, Mn, Fe, Ni, and Ba) on pure glassy areas (approximately ten in each particle) selected on the basis of optical and BSE images (avoiding all clasts and inclusions) with an electron microprobe to obtain average glass compositions of each single agglutinate.

  9. Caprine herpesvirus 1 (CpHV-1) vaginal infection of goats: clinical efficacy of fig latex.

    PubMed

    Camero, Michele; Marinaro, Mariarosaria; Losurdo, Michele; Larocca, Vittorio; Bodnar, Livia; Patruno, Giovanni; Buonavoglia, Canio; Tempesta, Maria

    2016-01-01

    The latex of Ficus carica Linn. (Moraceae) has been shown to interfere with the replication of caprine herpesvirus (CpHV)-1 in vitro. The present study was undertaken to determine the efficacy of vaginal administration of fig latex in goats experimentally infected with CpHV-1. The fig latex reduced the clinical signs of the herpetic disease although it slightly influenced the titres of CpHV-1 shed. Thus, the fig latex maintained a partial efficacy in vivo.

  10. The Classroom-Friendly ABO Blood Types Kit: Blood Agglutination Simulation

    ERIC Educational Resources Information Center

    Arnold, Savittree Rochanasmita; Kruatong, Tussatrin; Dahsah, Chanyah; Suwanjinda, Duongdearn

    2012-01-01

    The classroom-friendly ABO blood type kit was developed by combining advantages of modelling and a simulation laboratory to teach the topics of ABO blood types and blood transfusion. Teachers can easily simulate the agglutination reaction on a blood type testing plate in the classroom, and show the students how this reaction occurs by using the…

  11. Reading Development in Agglutinative Languages: Evidence from Beginning, Intermediate, and Adult Basque Readers

    ERIC Educational Resources Information Center

    Acha, Joana; Laka, Itziar; Perea, Manuel

    2010-01-01

    Do typological properties of language, such as agglutination (i.e., the morphological process of adding affixes to the lexeme of a word), have an impact on the development of visual word recognition? To answer this question, we carried out an experiment in which beginning, intermediate, and adult Basque readers (n = 32 each, average age = 7, 11,…

  12. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., high agglutinability, but are not sensitive to negative and nonspecific sera. The stock cultures may be... hours at 37 °C. The antigenic composition and purity of the stock cultures should be checked... cultures prepared from the stock cultures of the selected strains. The antigen-growing tubes or...

  13. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., high agglutinability, but are not sensitive to negative and nonspecific sera. The stock cultures may be... hours at 37 °C. The antigenic composition and purity of the stock cultures should be checked... cultures prepared from the stock cultures of the selected strains. The antigen-growing tubes or...

  14. Controllable preparation of high-yield magnetic polymer latex.

    PubMed

    Wu, Chun-Chao; Kong, Xiang-Ming; Yang, Hai-Long

    2011-09-01

    In order to overcome the low conversion and complex post-treatment, four different polymerization procedures were adopted to prepare the magnetic polymer latexes. The results clearly show that the strategy using magnetic emulsion template-dosage is the most effective and feasible. Based on the optimized procedure, various factors including the type of initiators such as oil soluble initiator, water soluble initiator, redox initiator system, crosslinking agent, functional monomers etc. were systematically studied. Magnetic polymer latex with high monomer conversion of 83% and high magnet content of 31.8% was successfully obtained. Besides, core-shell structured magnetic polymer latex with good film forming property was also prepared, which is promising for potential applications such as magnetic coatings and modification of cementitious materials with controlled polymer location.

  15. The first products made in space - Monodisperse latex particles

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; El-Aasser, m. S.; Micale, F. J.; Sudol, E. D.; Tseng, C.-M.; Sheu, H.-R.; Kornfeld, D. M.

    1987-01-01

    Monodisperse latex particles developed by seeded emulsion polymerization on various Space Shuttle flights are analyzed. The flight hardware was composed of a monodisperse latex reactor and a support electronics package, and the particles were examined by optical microscopy and TEM. Data on the particle size distributions, larger and smaller off-size particles, and conversion-time curves for the particles are examined and compared to ground-based results. It is observed that the ground-based polymerizations have more coagulum than the flight polymerizations; the flight latex particles have narrower size distributions than the ground particles; and the number of off-size larger particles in the flight particles is smaller than in the ground data.

  16. Identification and characterization of Euphorbia nivulia latex proteins.

    PubMed

    Badgujar, Shamkant B; Mahajan, Raghunath T

    2014-03-01

    The protein profile of latex of Euphorbia nivulia Buch.-Ham. is established. Three new proteins viz., Nivulian-I, II and III have been purified to homogeneity from the latex. The relative molecular masses of Nivulian-I, II and III are 31,486.985, 43,670.846 and 52,803.470 Da respectively. Nivulian-I is a simple type of protein while Nivulian-II and III are glycoproteins. Peptide mass fingerprint analysis revealed peptides of these proteins match with Tubulin alpha-1 chain of Eleusine indica, Maturase K of Banksia quercifolia and hypothetical protein of Zea mays respectively. Tryptic digestion profile of Nivulian-I, II and III, infer the exclusive nature of latex origin proteins and may be new and are additive molecules in the dictionaries of phytoproteins or botany. This is the first of its kind, regarding characterization and validation of Nivulian-I, II and III with respect to peptide sequencing.

  17. Prevalence of latex hypersensitivity among health care workers in Malaysia.

    PubMed

    Shahnaz, M; Azizah, M R; Hasma, H; Mok, K L; Yip, E; Ganesapillai, T; Suraiya, H; Nasuruddin, B A

    1999-03-01

    Health care workers have been reported to constitute one of the few high-risk groups related to IgE-mediated hypersensitivity associated with the use of latex products. This paper describes the first ever study of prevalence carried out in Malaysia among these workers. One hundred and thirty health care personnel from Hospital Kuala Lumpur were skin tested. Extracts used were prepared from seven different brands of natural rubber latex gloves with varying levels of extractable protein (EPRRIM). Out of the 130 volunteers, 4 (3.1%) had positive skin test to latex with extracts with high levels of EPRRIM (> 0.7 mg/g). The prevalence among the Malaysian health care workers can be considered to be low in comparison to that of some consumer countries as the USA which reported a prevalence of as high as 16.9%.

  18. Definition of fibronectin-mediated uptake of gelatinized latex by liver slices and macrophages.

    PubMed

    Molnar, J; Galles, M; Beezhold, D; Lai, M Z; Ku, C S; Van Alten, P J

    1987-10-01

    These studies show that both liver slices and macrophages carried out fibronectin concentration-dependent uptake of 125I-labeled gelatin-coated latex (test latex). Lack of phagocytosis of test latex by liver slices was shown directly by electron microscopy and indirectly by trypsin treatment, which caused the release of all test latex taken up in response to fibronectin. Inhibitors of phagocytosis did not alter this uptake. On the other hand, trypsin released only a portion of test latex from macrophages. Inhibitors of phagocytosis did not effect the released radioactive particles from macrophages but greatly reduced the trypsin-resistant radioactivity, taken as representing phagocytized particles. Opsonization of test latex with fibronectin did not require heparin but its association with liver slices occurred only in the presence of heparin. Macrophages, however, readily bound and internalized the opsonized test latex and heparin only potentiated these reactions. Gelatin competed with test latex for fibronectin for opsonization, but did not inhibit binding and phagocytosis of fibronectin-test latex complexes. Finally, soluble fibronectin-gelatin complexes did not compete for binding and phagocytosis of fibronectin-test latex complexes. Thus, fibronectin concentrated on the surface of latex is preferred for interaction with the fibronectin receptor of macrophages. Gelatin, however, was not essential for this reaction, because fibronectin directly coupled to latex was also readily taken up.

  19. 40 CFR 428.40 - Applicability; description of the latex rubber subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... latex rubber subcategory. 428.40 Section 428.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex Rubber Subcategory § 428.40 Applicability; description of the latex rubber subcategory. The provisions...

  20. 40 CFR 428.40 - Applicability; description of the latex rubber subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... latex rubber subcategory. 428.40 Section 428.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex Rubber Subcategory § 428.40 Applicability; description of the latex rubber subcategory. The provisions...

  1. 40 CFR 428.40 - Applicability; description of the latex rubber subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... latex rubber subcategory. 428.40 Section 428.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex Rubber Subcategory § 428.40 Applicability; description of the latex rubber subcategory....

  2. 40 CFR 428.40 - Applicability; description of the latex rubber subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... latex rubber subcategory. 428.40 Section 428.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex Rubber Subcategory § 428.40 Applicability; description of the latex rubber subcategory....

  3. 40 CFR 428.40 - Applicability; description of the latex rubber subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... latex rubber subcategory. 428.40 Section 428.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Latex Rubber Subcategory § 428.40 Applicability; description of the latex rubber subcategory....

  4. The Production of Nominal and Verbal Inflection in an Agglutinative Language: Evidence from Hungarian

    PubMed Central

    Peckham, Don; Szanka, Szilvia; Gazso, Dorottya; Lovassy, Noemi; Ullman, Michael T.

    2015-01-01

    The contrast between regular and irregular inflectional morphology has been useful in investigating the functional and neural architecture of language. However, most studies have examined the regular/irregular distinction in non-agglutinative Indo-European languages (primarily English) with relatively simple morphology. Additionally, the majority of research has focused on verbal rather than nominal inflectional morphology. The present study attempts to address these gaps by introducing both plural and past tense production tasks in Hungarian, an agglutinative non-Indo-European language with complex morphology. Here we report results on these tasks from healthy Hungarian native-speaking adults, in whom we examine regular and irregular nominal and verbal inflection in a within-subjects design. Regular and irregular nouns and verbs were stem on frequency, word length, and phonological structure, and both accuracy and response times were acquired. The results revealed that the regular/irregular contrast yields similar patterns in Hungarian, for both nominal and verbal inflection, as in previous studies of non-agglutinative Indo-European languages: the production of irregular inflected forms was both less accurate and slower than of regular forms, both for plural and past-tense inflection. The results replicate and extend previous findings to an agglutinative language with complex morphology. Together with previous studies, the evidence suggests that the regular/irregular distinction yields a basic behavioral pattern that holds across language families and linguistic typologies. Finally, the study sets the stage for further research examining the neurocognitive substrates of regular and irregular morphology in an agglutinative non-Indo-European language. PMID:25769039

  5. Interactions with lectins and agglutination profiles of clinical, food, and environmental isolates of Listeria.

    PubMed Central

    Facinelli, B; Giovanetti, E; Casolari, C; Varaldo, P E

    1994-01-01

    On the basis of preliminary trials with 14 collection strains of Listeria, five lectins (Canavalia ensiformis, concanavalin A; Griffonia simplicifolia lectin I; Helix pomatia agglutinin; Ricinus communis agglutinin; and Triticum vulgaris wheat germ agglutinin) were selected to set up a microtiter agglutination assay. The lectin agglutination profiles of 174 clinical, food, and environmental strains of Listeria monocytogenes, Listeria innocua, and Listeria seeligeri were investigated. Data on the standard determination of the antigenic structure were available for clinical strains; nonclinical isolates were assigned to serogroup 1 or 4 with commercial antisera. The listeria-lectin interaction was related to serological type rather than species; in particular, the strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, 3a, 3b, and 7 were never agglutinated by G. simplicifolia lectin I. The five-lectin set proved to be capable of detecting differences between serologically identical isolates of L. monocytogenes. Of the 150 isolates of this species, 144 were distributed over 15 different lectin agglutination profiles and 6 autoagglutinated, the overall typeability being 96%. However, the profiles encountered among L. monocytogenes isolates were not randomly distributed. With strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, and 3b, the clinical isolates fell into only two of the eight patterns recorded overall; with strains of serogroup 4 and serovar 4b, food and environmental isolates were distributed over eight of the nine patterns found in total, while clinical isolates were distributed over five patterns. In a comparative study of 15 epidemiologically relevant isolates of L. monocytogenes from five distinct outbreaks, strains with identical phage types and/or DNA fingerprints displayed identical lectin profiles. The heterogeneity of agglutination profiles may form the basis of a new approach to L. monocytogenes typing

  6. The production of nominal and verbal inflection in an agglutinative language: evidence from Hungarian.

    PubMed

    Nemeth, Dezso; Janacsek, Karolina; Turi, Zsolt; Lukacs, Agnes; Peckham, Don; Szanka, Szilvia; Gazso, Dorottya; Lovassy, Noemi; Ullman, Michael T

    2015-01-01

    The contrast between regular and irregular inflectional morphology has been useful in investigating the functional and neural architecture of language. However, most studies have examined the regular/irregular distinction in non-agglutinative Indo-European languages (primarily English) with relatively simple morphology. Additionally, the majority of research has focused on verbal rather than nominal inflectional morphology. The present study attempts to address these gaps by introducing both plural and past tense production tasks in Hungarian, an agglutinative non-Indo-European language with complex morphology. Here we report results on these tasks from healthy Hungarian native-speaking adults, in whom we examine regular and irregular nominal and verbal inflection in a within-subjects design. Regular and irregular nouns and verbs were stem on frequency, word length, and phonological structure, and both accuracy and response times were acquired. The results revealed that the regular/irregular contrast yields similar patterns in Hungarian, for both nominal and verbal inflection, as in previous studies of non-agglutinative Indo-European languages: the production of irregular inflected forms was both less accurate and slower than of regular forms, both for plural and past-tense inflection. The results replicate and extend previous findings to an agglutinative language with complex morphology. Together with previous studies, the evidence suggests that the regular/irregular distinction yields a basic behavioral pattern that holds across language families and linguistic typologies. Finally, the study sets the stage for further research examining the neurocognitive substrates of regular and irregular morphology in an agglutinative non-Indo-European language.

  7. Radiation vulcanization of natural rubber latex with polyfunctional monomers

    SciTech Connect

    Makuuchi, K.; Hagiwara, M.

    1984-03-01

    Natural rubber latex was irradiated with ..gamma..-rays from Co-60 in the presence of polyfunctional monomers to accelerate crosslinking of rubber molecules. Hydrophobic monomers were more effective in accelerating the vulcanization than were hydrophilic monomers. This was ascribed to high solubility of hydrophobic monomers in rubber particles. Among the hydrophobic monomers, neopentylglycol dimethacrylate (NPG) exhibited the highest efficiency in accelerating the vulcanization. Advantages of using NPG are high colloidal stability of the irradiated latex and high thermal stability of dried rubber film.

  8. Human fibrinogen adsorption on positively charged latex particles.

    PubMed

    Zeliszewska, Paulina; Bratek-Skicki, Anna; Adamczyk, Zbigniew; Cieśla, Michał

    2014-09-23

    Fibrinogen (Fb) adsorption on positively charged latex particles (average diameter of 800 nm) was studied using the microelectrophoretic and the concentration depletion methods based on AFM imaging. Monolayers on latex were adsorbed from diluted bulk solutions at pH 7.4 and an ionic strength in the range of 10(-3) to 0.15 M where fibrinogen molecules exhibited an average negative charge. The electrophoretic mobility of the latex after controlled fibrinogen adsorption was systematically measured. A monotonic decrease in the electrophoretic mobility of fibrinogen-covered latex was observed for all ionic strengths. The results of these experiments were interpreted according to the three-dimensional electrokinetic model. It was also determined using the concentration depletion method that fibrinogen adsorption was irreversible and the maximum coverage was equal to 0.6 mg m(-2) for ionic strength 10(-3) M and 1.3 mg m(-2) for ionic strength 0.15 M. The increase of the maximum coverage was confirmed by theoretical modeling based on the random sequential adsorption approach. Paradoxically, the maximum coverage of fibrinogen on positively charged latex particles was more than two times lower than the maximum coverage obtained for negative latex particles (3.2 mg m(-2)) at pH 7.4 and ionic strength of 0.15 M. This was interpreted as a result of the side-on adsorption of fibrinogen molecules with their negatively charged core attached to the positively charged latex surface. The stability and acid base properties of fibrinogen monolayers on latex were also determined in pH cycling experiments where it was observed that there were no irreversible conformational changes in the fibrinogen monolayers. Additionally, the zeta potential of monolayers was more positive than the zeta potential of fibrinogen in the bulk, which proves a heterogeneous charge distribution. These experimental data reveal a new, side-on adsorption mechanism of fibrinogen on positively charged surfaces and

  9. Peptidases and peptidase inhibitors in gut of caterpillars and in the latex of their host plants.

    PubMed

    Ramos, Márcio V; Pereira, Danielle A; Souza, Diego P; Silva, Maria-Lídia S; Alencar, Luciana M R; Sousa, Jeanlex S; Queiroz, Juliany-Fátima N; Freitas, Cleverson D T

    2015-01-01

    Studies investigating the resistance-susceptibility of crop insects to proteins found in latex fluids have been reported. However, latex-bearing plants also host insects. In this study, the gut proteolytic system of Pseudosphinx tetrio, which feeds on Plumeria rubra leaves, was characterized and further challenged against the latex proteolytic system of its own host plant and those of other latex-bearing plants. The gut proteolytic system of Danaus plexippus (monarch) and the latex proteolytic system of its host plant (Calotropis procera) were also studied. The latex proteins underwent extensive hydrolysis when mixed with the corresponding gut homogenates of the hosted insects. The gut homogenates partially digested the latex proteins of foreign plants. The fifth instar of D. plexippus that were fed diets containing foreign latex developed as well as those individuals who were fed diets containing latex proteins from their host plant. In vitro assays detected serine and cysteine peptidase inhibitors in both the gut homogenates and the latex fluids. Curiously, the peptidase inhibitors of caterpillars did not inhibit the latex peptidases of their host plants. However, the peptidase inhibitors of laticifer origin inhibited the proteolysis of gut homogenates. In vivo analyses of the peritrophic membrane proteins of D. plexippus demonstrate resistance against latex peptidases. Only discrete changes were observed when the peritrophic membrane was directly treated with purified latex peptidases in vitro. This study concludes that peptidase inhibitors are involved in the defensive systems of both caterpillars and their host plants. Although latex peptidase inhibitors inhibit gut peptidases (in vitro), the ability of gut peptidases to digest latex proteins (in vivo) regardless of their origin seems to be important in governing the resistance-susceptibility of caterpillars.

  10. Better nirodhs now from Hindustan latex Ltd.

    PubMed

    1983-01-26

    On April 5, 1969, Hindustan Latex Limited (HLL), a Public Sector Enterprise under the Ministry of Health and Family Welfare of the Government of India, was established to produce "NIRODH"--condoms--for the nation's family planning program. The 1st factory for the manufacture of the male contraceptive was created at Trivandrum in Kerala State with Japanese collaboration. The production capacity at inception was 144 million pieces; this was doubled in 1977. From inception the company has manufactured nearly 2000 million pieces. The manufacture of condoms involves 4 main stages: compounding; moulding; vulcanizing; and electronic testing and inspection (quality control). Each of these stages of development is reviewed. HLL has achieved considerable progress and growth during the past year and recorded an all time high profit of Rs. 54.76 lakhs for 1981-82. Recently, the company delcared a 5% dividend on the paid up capital to be paid by India's government. This was possible because of the excellent working results the company achieved during the last year. During 1980-81 the company produced only 105.23 pieces of condoms. In 1981-82 the company produced 265.7 million pieces agianst the target set of 240 million pieces. For the excellent working performance of last year the company paid a good performance award to its employees apart from the minimum statutory bonus. The company has set a production target of 300 million pieces of condoms during 1982-82. HLL has planned for modernization of its 14-year old existing plant and machinery and for creating a new plant with installed capacity of 300 million pieces. The new plant is expected to be set up adjacent to the existing plant. The technical team has recommended the utilization of Japanese technology, one of the most advanced process technologies in the world for the manufacture of prophylactics, incorporating maximum automation and improvements in the process machinery. The new plant is expected to produce condoms of

  11. Health risk in hospitals through airborne allergens for patients presensitised to latex.

    PubMed

    Baur, X; Ammon, J; Chen, Z; Beckmann, U; Czuppon, A B

    1993-11-06

    Two nurses had to stop practicing because of severe work-related allergic respiratory or systemic symptoms. Both developed similar symptoms within a short time when they attended hospitals as outpatients or visitors or consulted a doctor or dentist, even when they had no direct contact with latex articles. The airborne latex allergen concentration in one room that induced symptoms was 128 ng per m3. In skinprick tests both women showed positive reactions to the phosphated cornstarch powder used to prevent latex gloves sticking together, but only when the powder had been in contact with latex. This powder seems a likely vehicle for the airborne latex allergen.

  12. [Evaluation of the usefulness of the agglutination test with Mangifera indica extract for the identification of pathogenic Yersinia enterocolitica strains].

    PubMed

    Kałuzewski, S; Gierczyński, R; Szych, J; Jagielski, M

    1997-01-01

    The study was performed on 137 Y. enterocolitica strains belonging to various serological groups, including 75 03 group strains isolated form human clinical material. The agglutination test on slides was carried out on this strains using Mangifera indica extract of own production. Agglutinating preparation obtained from the seeds of M. indica agglutinated Y. enterocolitica organisms possessing the pVY plasmid and CRMOX+ phenotype in dilutions to 1.56 micrograms/ml. In identification tests conducted parallelly agglutination solution was used in concentrations of 100 and 10 micrograms/ml. All clones of Y. enterocolitica from O3 group from cultures at 37 degrees C and with CRMOX+ phenotype possessing the pVY plasmid were agglutinated by the extract. Agglutination failed to develop in the cultures of these clones incubated at 25 degrees C. Yersinia clones not containing the pVY plasmid with CRMOX- phenotype were resistant to agglutination. The virulence plasmid was found in 44 out of 75 strains of Y. enterocolitica O3 and was identified by restriction analysis after plasmid DNA digestion with Eco RI enzyme. The obtained results agreed with those of Wauters et al. in 1995 and confirmed the opinion of these authors on the usefulness of the test with M. indica agglutinin for the identification of virulent Y. enterocolitica strains.

  13. A new quantitative in vitro for the detection of latex-specific IgE antibodies.

    PubMed

    Moussadeh, M; Hamedi, N; Alem, N; Alem, M

    1999-12-01

    Immediate-type hypersensitivity to latex allergens has resulted in anaphylactic shock and death in numerous reported cases. The allergenic proteins of latex are contained within the natural rubber extract of Hevea brasiliensis and are eluted into the final product during the manufacturing process. The quantity and types of latex allergens found in different latex products depends on the manufacturing process. Not all of these allergens are available for use in the latex prick skin test, and as a result, such tests may not be conclusive. Furthermore, application of such allergens to the skin of undiagnosed hypersensitive individuals may have harmful effects on their health. Therefore, it is important to be able to utilize in vitro methods, which reliably identify latex allergy without placing hypersensitive individuals at risk. We have developed a relatively simple and new enzyme immuno-assay (EIA) method for the detection of latex allergy. This in vitro method is quantitative and allows for the classification of allergy to latex in a short time. In comparative studies, ninety-nine serum specimens with documented clinical history of latex allergy were tested by this method, and the results paralleled those of the skin prick test performed by an independent group. The data showed that the specificity and sensitivity of our assay approaches 97.5% and 100%, respectively. We conclude that, by using a simple assay, the detection of specific IgE to latex proteins may be valuable for screening individuals and for the diagnosis of allergy to latex.

  14. Anthelmintic activity of the latex of Ficus species.

    PubMed

    de Amorin, A; Borba, H R; Carauta, J P; Lopes, D; Kaplan, M A

    1999-03-01

    The latex of some species of Ficus (Moraceae) has been traditionally used as vermifuge in Central and South America. It has been accepted that anthelmintic activity is due to a proteolytic fraction called ficin. In the present study, the anthelmintic activity of the latex of Ficus insipida Willd. and Ficus carica L. has been investigated in NIH mice naturally infected with Syphacia obvelata, Aspiculuris tetraptera and Vampirolepis nana. The latex of F. insipida, administered by intragastric route in doses of 4 ml/kg/day during three consecutive days, were effective in the removal of 38.6% of the total number of S. obvelata, being inexpressive in the removal of A. tetraptera (8.4%) and segments of V. nana (6.3%). The latex of F. carica, administered in doses of 3 ml/kg/day, during three consecutive days, was effective in the removal of S. obvelata (41.7%) and it did not produce significant elimination of A. tetraptera (2.6%) and V. nana (8.3%). The observed high acute toxicity with hemorrhagic enteritis, in addition to a weak anthelmintic efficacy, do not recommend the use of these lattices in traditional medicine.

  15. Production of large-particle-size monodisperse latexes

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; El-Aasser, M. L.; Micale, F. J.; Sudol, E. D.; Tseng, C. M.; Silwanowicz, A.

    1984-01-01

    The research program achieved two objectives: (1) it has refined and extended the experimental techniques for preparing monodisperse latexes in quantity on the ground up to a particle diameter of 10 microns; and (2) it has demonstrated that a microgravity environment can be used to grow monodisperse latexes to larger sizes, where the limitations in size have yet to be defined. The experimental development of the monodisperse latex reactor (MLR) and the seeded emulsion polymerizations carried out in the laboratory prototype of the flight hardware, as a function of the operational parameters is discussed. The emphasis is directed towards the measurement, interpretation, and modeling of the kinetics of seeded emulsion polymerization and successive seeded emulsion polymerization. The recipe development of seeded emulsion polymerization as a function of particle size is discussed. The equilibrium swelling of latex particles with monomers was investigated both theoretically and experimentally. Extensive studies are reported on both the type and concentration of initiators, surfactants, and inhibitors, which eventually led to the development of the flight recipes. The experimental results of the flight experiments are discussed, as well as the experimental development of inhibition of seeded emulsion polymerization in terms of time of inhibition and the effect of inhibitors on the kinetics of polymerization.

  16. Production of Large-Particle-Size Monodisperse Latexes in Microgravity

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; Micale, F. J.; El-Aasser, M. S.; Kornfeld, M.

    1985-01-01

    A latex is a suspension of very tiny (micrometer-size) plastic spheres in water, stabilized by emulsifiers. The growth of billions of these tiny plastic spheres to sizes larger than can be grown on Earth is attempted while keeping all of them exactly the same size and perfectly spherical. Thus far on several of the Monodisperse Latex Reactor (MLR) flights, the latex spheres have been returned to Earth with standard deviations of better than 1.4%. In microgravity the absence of buoyancy effects has allowed growth of the balls up to 30 micrometers in diameter thus far. The MLR has now flown 5 times on the Shuttle. The MLR has now produced the first commercial space product; that is the first commercial material ever manufactured in space and marketed on Earth. Once it is demonstrated that these large-size-monodisperse latexes can be routinely produced in quantity and quality, they can be marketed for many types of scientific applications. They can be used in biomedical research for such things as drug carriers and tracers in the body, human and animal blood flow studies, membrane and pore-sizing in the body, and medical diagnostic tests.

  17. Latex use as an occlusive membrane for guided bone regeneration.

    PubMed

    Ereno, Cibele; Guimarães, Sérgio A Catanzaro; Pasetto, Silvana; Herculano, Rondinelli Donizetti; Silva, Cecília Pereira; Graeff, Carlos F O; Tavano, Orivaldo; Baffa, Oswaldo; Kinoshita, Angela

    2010-12-01

    Latex extracted from Hevea brasiliensis was used as an occlusive membrane for guided bone regeneration. Twenty-four rabbits were divided in two groups: treated and control group. Critical size bone defects (2 cm × 1 cm) were surgically made in the rabbit calvarium. Two latex membranes were implanted in each animal of the treated group, whereas the control defect was filled only with autogenous blood clot. After 15, 30, 60, and 120 days, animals from each group were euthanized, and the samples with regenerated bone were removed. No signs of allergy or rejection were noticed around the calvarial bone defect of the treated group. In the histological analysis, no foreign body inflammatory reaction was observed in the adjacent tissues in contact with the membranes demonstrating that latex can be used at injured sites as an aid in the healing process. Histological analysis, digital radiography, and electron spin resonance were used to evaluate the progress of bone repair. The results show significant differences between groups (p < 0.05) suggesting that latex membranes accelerates healing in critical bone defects.

  18. Latex of "coroa de cristo" (Euphorbia splendens): an effective molluscicide.

    PubMed

    de Vasconcellos, M C; Schall, V T

    1986-01-01

    An aqueous solution of the latex of "coroa de cristo" (Euphorbia splendens var. hislopii) showed molluscicide action (LD90) at a concentration lower than 0.5 ppm on Biomphalaria glabrata and B. tenagophila reared in laboratory and at a concentration lower than 4.0 ppm for field B. tenagophila.

  19. Cutting height effects on guayule latex, rubber and resin yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guayule (Parthenium argentatum Gray) is a perennial shrub native to the Chihuahuan Desert. While guayule traditionally has been cultivated for rubber, more recently it is being cultivated for its hypoallergenic latex. Other uses including termite resistant wood products and as an energy source have ...

  20. SUBSTRATE EFFECTS ON VOC EMISSIONS FROM A LATEX PAINT

    EPA Science Inventory

    The effects of two substrates -- a stainless steel plate and a gypsum board -- on the volatile organic compound (VOC) emissions from a latex paint were evaluated by environmental chamber tests. It was found that the amount of VOCs emitted from the painted stainless steel was 2 to...

  1. Method accurately measures mean particle diameters of monodisperse polystyrene latexes

    NASA Technical Reports Server (NTRS)

    Kubitschek, H. E.

    1967-01-01

    Photomicrographic method determines mean particle diameters of monodisperse polystyrene latexes. Many diameters are measured simultaneously by measuring row lengths of particles in a triangular array at a glass-oil interface. The method provides size standards for electronic particle counters and prevents distortions, softening, and flattening.

  2. Characterization of associated proteins and phospholipids in natural rubber latex.

    PubMed

    Sansatsadeekul, Jitlada; Sakdapipanich, Jitladda; Rojruthai, Porntip

    2011-06-01

    Non-rubber components present in natural rubber (NR) latex, such as proteins and phospholipids, are presumed to be distributed in the serum fraction as well as surrounding the rubber particle surface. The phospholipid-protein layers covering the rubber particle surface are especially interesting due to their ability to enhance the colloidal stability of NR latex. In this study, we have characterized the components surrounding the NR particle surface and investigated their role in the colloidal stability of NR particles. Proteins from the cream fraction were proteolytically removed from the NR latex and compare to those from the serum fractions using SDS-polyacrylamide gel electrophoresis revealing that both fractions contained similar proteins in certain molecular weights such as 14.5, 25 and 27 kDa. Phospholipids removed from latex by treatment with NaOH were analyzed using (1)H-NMR spectroscopy and several major signals were assignable to -(CH(2))(n)-, -CH(2)OP, -CH(2)OC═O and -OCH(2)CH(2)NH-. These signals are important evidence that indicates phospholipids associate with the rubber chain. The colloidal behavior of rubber lattices before and after removal of protein-lipid membrane was evaluated by zeta potential analysis and scanning electron microscope (SEM). The lowest zeta potential value of NR particles was observed at pH 10, consequently leading to the highest stability of rubber particles. Additionally, SEM micrographs clearly displayed a gray ring near the particle surface corresponding to the protein-lipid membrane layer.

  3. Pilot scale experiments on radiation vulcanization of NR latex

    NASA Astrophysics Data System (ADS)

    Ridwan, M.

    The potential of irradiated latex as raw material of commercial use is under testing on pilot plant scale in Indonesia which has 225 kCi Co-60 irradiation facility and can irradiate 1000 tonnes of centrifuged latex per annum. The facility was jointly designed by BATAN of Indonesia and JAERI of Japan and was jointly financed by UNDP/IAEA, Government of Japan and Government of Indonesia under UNDP/IAEA Regional Cooperative Agreement Project on Industrial Application of Isotopes and Radiation Technology. The facility is a water pool type and can accomodate 400 kCi Co-60. The Co-60 rack has two shapes, plate and cylindrical shapes. The plate shape source is used for natural rubber latex irradiation and the cylindrical one is used for other irradiation services. The vulcanization system consists of three major components : emulsification unit ( height : 650 mm, diameter 500 mm ), mixing unit ( height : 1900mm, diameter 1200 mm ) and vulcanization reactor ( height : 1800 mm, diameter 1300 mm ). The first two components are located outside shielded room while the third one-in irradiation room. The radiation vulcanization process is a much simpler energy saving process comparedto the conventional thermal process which has two vulcanization steps before and after dipping. The physical and mechanical properties of irradiated NR Latex are comparable to those of sulfur vulcanized, and depend on many factors such as irradiation dose, sensitizer content, dry rubber content and storage time.

  4. The Use of Latex Gloves in the School Setting

    ERIC Educational Resources Information Center

    Purcell, Cathy Koeppen

    2006-01-01

    In 1987, when the U.S. Centers for Disease Control and Prevention recommended the use of universal precautions in response to the HIV/AIDS epidemic, the demand for medical gloves dramatically increased. Unfortunately, the manufacturing techniques for the most widely-used gloves--natural rubber latex--also changed, in order to expedite production.…

  5. The formation of small scale granularities in latex particles

    NASA Technical Reports Server (NTRS)

    Zukoski, C. F.; Saville, D. A.

    1985-01-01

    A series of latices were synthesized using emulsifier-free emulsion copolymerization of styrene and sodium styrene sulfonic acid. The final latex particles display an internal granular structure which can be ascribed to the primary particles present in the early stages of particle growth. In these systems, the primary particles appear to have maintained their integrity during the swelling and growth stage.

  6. Effects on film structure on mechanical and adhesion properties of latex films

    SciTech Connect

    Charmeau, J.Y.; Holl, Y.; Kientz, E.

    1995-12-31

    In order to investigate the effect of the particular structure of latex films on mechanical (stress-strain behavior) and adhesion (measured by peeling) properties, this work compares these characteristics for latex films and corresponding {open_quotes}solution films{close_quotes}. Solution films were obtained by dissolving the latex film in an appropriate solvent and forming a new film by evaporating the solvent. Four different systems were studied. It was shown that latex films have Young`s moduli systematically much higher than the corresponding solution films. This is due to the fact that the hydrophilic shells of the latex particles form a continuous phase in the latex film which increases the modulus thanks to polar interactions. However, adhesion energy for latex films is always smaller than for solution films. This is interpreted in terms of structure of the film-support interface and dissipative processes within the bulk of the films.

  7. [Diagnosis of some yeasts in Metschnikowia genus with the aid of Salmonella cholerae-suis O agglutinating serum (author's transl)].

    PubMed

    Aksoycan, N

    1980-04-01

    In this paper a common antigenic factor among Salmonella choleraesuis 0 antigen and standard Metschnikowia bicuspidata var. bicuspidata and M. pulcherrima strains is shown. This common factor was not present in M. bicuspidata var. australis, M. bicuspidata var. california, M. krissii and M. reukaufii strains. M. bicuspidata var. chathamia and M. zobellii showed agglutination in the previous experiments. According to these results, the use of S. choleraesuis 0:6,7 agglutinating serum for slide and tube agglutination tests can be a diagnostic aid for typing above mentioned Metschnikowia strains along with the other tests.

  8. Elemental X-ray mapping of agglutinated foraminifer tests: a non- destructive technique for determining compositional characteristics.

    USGS Publications Warehouse

    Commeau, R.F.; Reynolds, Leslie A.; Poag, C.W.

    1985-01-01

    The composition of agglutinated foraminiferal tests vary remarkably in response to local substrate characteristics, physiochemical properties of the water column and species- dependant selectivity of test components. We have employed a technique that combines a scanning electron microscope with an energy dispersive X-ray spectrometer system to identify major and minor elemental constituents of agglutinated foraminiferal walls. As a sample is bombarded with a beam of high energy electrons, X-rays are generated that are characteristic of the elements present. As a result, X- ray density maps can be produced for each of several elements present in the tests of agglutinated foraminifers. -Authors

  9. The relationship of the lunar regolith less than 10-microns fraction and agglutinates. II - Chemical composition of agglutinate glass as a test of the 'fusion of the finest fraction' /F3/ model

    NASA Technical Reports Server (NTRS)

    Walker, R. J.; Papike, J. J.

    1982-01-01

    Agglutinate glasses from nine Apollo soils have been studied using an automated electron microprobe technique in order to test the fusion of the finest fraction model proposed by Papike (1981). The nine average agglutinate glass compositions are compared with the calculated fused-soil-free compositions, the bulk compositions and the 90-20 micron fraction compositions of the soils in which they are found. It is found that the agglutinate glass data are consistent with the composition of most of the fractions finer than 10 microns, allowing for the volatile loss of K2O and Na2O; some inconsistencies that do arise may result from the degree of soil maturity and the amount of material finer than 10 microns. It is concluded that the fusion of the finest fraction model is a good first approximation of mechanisms affecting the formation of agglutinate glass.

  10. MEMS reagent and sample handling procedure: Feasibility of viral antibody detection by passive immune agglutination

    NASA Technical Reports Server (NTRS)

    Bailey, G. D.; Tenoso, H. J.

    1975-01-01

    An attempt was made to develop a test requiring no preadsorption steps for the assessment of antibodies to rubella and mumps viruses using the passive immune agglutination (PIA) method. Both rubella and mumps antigens and antibodies were prepared. Direct PIA tests, using rubella antigen-coated beads, and indirect PIA tests, using rubella antibody-coated beads, were investigated. Attempts, using either method, were unsuccessful. Serum interference along with nonspecific agglutination of beads by the rubella antigen resulted in no specific response under the test conditions investigated. A new, highly sensitive approach, the enzyme immunoassay (EIA) test system, is recommended to overcome the nonspecificity. This system is a logical outgrowth of some of the solid phase work done on MEMS and represents the next generation tests system that can be directly applied to early disease detection and monitoring.

  11. Alpha mating type-specific expression of mutations leading to constitutive agglutinability in Saccharomyces cerevisiae.

    PubMed Central

    Doi, S; Yoshimura, M

    1985-01-01

    Two mutants of Saccharomyces cerevisiae have been isolated and characterized. The mutants were constitutively agglutinable at 36 degrees C, the temperature at which wild-type cells agglutinate only after induction by mating pheromone. The mutant cells had other properties specific for the normal alpha cell type, i.e., conjugation with a cells, response to a mating pheromone, and production of alpha mating pheromone. The two mutations, cag1 and cag2, were recessive and expressed only in alpha cells. cag1 is linked very closely to the MAT locus, but cag2 is unlinked to the MAT locus. These cag mutations complemented ste3-1. These results indicate that CAG genes are novel alpha-specific genes involved in the regulation of sex agglutinin synthesis. PMID:3881403

  12. Lead isotopic studies of lunar soils - Their bearing on the time scale of agglutinate formation

    NASA Technical Reports Server (NTRS)

    Church, S. E.; Tilton, G. R.; Chen, J. H.

    1976-01-01

    Fines (smaller than 75 microns) and bulk soil were studied to analyze loss of volatile lead; losses of the order of 10% to 30% radiogenic lead during the production of agglutinates are assessed. Lead isotope data from fine-agglutinate pairs are analyzed for information on the time scale of micrometeorite bombardment, from the chords generated by the data in concordia diagrams. Resulting mean lead loss ages were compared to spallogenic gas exposure ages for all samples. Labile parentless radiogenic Pb residing preferentially on or in the fines is viewed as possibly responsible for aberrant lead loss ages. Bulk soils plot above the concordia curve (in a field of excess radiogenic Pb) for all samples with anomalous ages.

  13. [Diagnostic value of agglutination reaction with buffered Brucella antigen stained with rose bengal].

    PubMed

    Chenchev, I; Khristoforov, L; Peshkov, I; Kostov, G; Mineva, I

    1978-01-01

    A specific buffered antigen has been obtained, employing a method developed by the authors, stained with Bengal rose and intended for performing a fast agglutination reaction to confirm brucellosis. The antigen produces a clear and demonstrative agglutination reaction with positive sera. Practically, the test is readily carried out, and can be made a routine both in every serologic laboratory and for investigations under field conditions. The reaction produced with this antigen can determine dependably the epizootic status on a farm or in the herd. The diagnostic value of the antigen is essential, especially with swine. Besides, it shows a wide a diagnostic scope for brucellosis with all species of animals (97--98 per cent).

  14. A novel arctigenin-containing latex glove prevents latex allergy by inhibiting type I/IV allergic reactions.

    PubMed

    Wang, Yong-Xin; Xue, Dan-Ting; Liu, Meng; Zhou, Zheng-Min; Shang, Jing

    2016-03-01

    The present study aimed at developing a natural compound with anti-allergic effect and stability under latex glove manufacturing conditions and investigating whether its anti-allergic effect is maintained after its addition into the latex. The effects of nine natural compounds on growth of the RBL-2H3 cells and mouse primary spleen lymphocytes were determined using MTT assay. The compounds included glycyrrhizin, osthole, tetrandrine, tea polyphenol, catechin, arctigenin, oleanolic acid, baicalin and oxymatrine. An ELISA assay was used for the in vitro anti-type I/IV allergy screening; in this process β-hexosaminidase, histamine, and IL-4 released from RBL-2H3 cell lines and IFN-γ and IL-2 released from mouse primary spleen lymphocytes were taken as screening indices. The physical stability of eight natural compounds and the dissolubility of arctigenin, selected based on the in vitro pharnacodynamaic screening and the stability evaluation, were detected by HPLC. The in vivo pharmacodynamic confirmation of arctigenin and final latex product was evaluated with a passive cutaneous anaphylaxis (PCA) model and an allergen-specific skin response model. Nine natural compounds showed minor growth inhibition on RBL-2H3 cells and mouse primary spleen lymphocytes. Baicalin and arctigenin had the best anti-type I and IV allergic effects among the natural compounds based on the in vitro pharmacodynamic screening. Arctigenin and catechin had the best physical stability under different manufacturing conditions. Arctigenin was the selected for further evaluation and proven to have anti-type I and IV allergic effects in vivo in a dose-dependent manner. The final product of the arctigenin-containing latex glove had anti-type I and IV allergic effects in vivo which were mainly attributed to arctigenin as proved from the dissolubility results. Arctigenin showed anti-type I and IV allergic effects in vitro and in vivo, with a good stability under latex glove manufacturing conditions

  15. Enhancement of Leptospira hardjo agglutination titers in sheep and goat serum by heat inactivation.

    PubMed

    Malkin, K

    1984-04-01

    Heat inactivation of sheep serum samples resulted in the detection of an additional 9% reactors to Leptospira hardjo that were negative on the initial test of fresh samples. Treatment with EDTA gave results generally similar to heat inactivation suggesting that complement was responsible for the inhibition of agglutination. Tests on heat inactivated serum from experimentally infected sheep and goats revealed enhanced titers or reactions which were not detected in fresh serum.

  16. Simplified spectraphotometric method for the detection of red blood cell agglutination.

    PubMed

    Ramasubramanian, Melur; Anthony, Steven; Lambert, Jeremy

    2008-08-01

    Human error is the most significant factor attributed to incompatible blood transfusions. A spectrophotometric approach to blood typing has been developed by examining the spectral slopes of dilute red blood cell (RBC) suspensions in saline, in the presence and absence of various antibodies, offering a technique for the quantitative determination of agglutination intensity [Transfusion39, 1051, 1999TRANAT0041-113210.1046/j.1537-2995.1999.39101051.x]. We offer direct theoretical prediction of the observed change in slope in the 660-1000 nm range through the use of the T-matrix approach and Lorenz-Mie theory for light scattering by dilute RBC suspensions. Following a numerical simulation using the T-matrix code, we present a simplified sensing method for detecting agglutination. The sensor design has been prototyped, fully characterized, and evaluated through a complete set of tests with over 60 RBC samples and compared with the full spectrophotometric method. The LED and photodiode pairs are found to successfully reproduce the spectroscopic determination of red blood cell agglutination.

  17. Sodium tetrathionate effect on papain purification from different Carica papaya latex crude extracts.

    PubMed

    Llerena-Suster, Carlos R; Priolo, Nora S; Morcelle, Susana R

    2011-01-01

    Papain from latex of Carica papaya was purified up to matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry homogeneity by salt precipitation from two different crude extract sources: a refined preparation obtained in our laboratory and a commercial one. Sodium tetrathionate was tested in the purification process to preserve the enzymatic activity of the peptidase. Purification was checked by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) and cation exchange chromatography, using commercial pure papain as standard for a rapid comparison. The best purification yields (3.4%) were obtained in presence of 30 mM sodium tetrathionate for the crude extract prepared in our laboratory. The described purification method proved to be robust and reliable to obtain pure papain on a preparative scale.

  18. A discussion of natural rubber latex allergy with special reference to children: clinical considerations.

    PubMed

    Eustachio, Nettis; Cristina, Colanardi Maria; Antonio, Ferrannini; Alfredo, Tursi

    2003-09-01

    Latex allergy is an increasingly common condition, because the use of latex products is widespread. Three types of reactions can occur in persons using natural latex rubber products: 1) Irritant contact dermatitis, 2) Allergic contact dermatitis, 3) and Type I hypersensitivity. Children's subpopulations at particular risk include: atopics, individuals with spina bifida, or individuals who required frequent surgical instrumentations. An association between allergy to latex and allergy to various fruits and vegetables has been reported. Recently, an homology between latex allergens and mold allergens has been reported leading to postulate a possible existence of a "latex-mold syndrome". Diagnosis of allergy is based initially on history, skin prick test and search for specific serum IgE. Provocation tests may confirm the suspicion, although these are seldom performed on children because they are not easy to bear with. The most effective strategy to decrease the incidence of NRL (natural rubber latex) sensitization is avoidance; however, this is virtually impossible, given the large number of latex products we encounter since childhood. Studies of secondary prophylaxis among children demonstrate that notwithstanding recommendations, children could manifest yet adverse reactions to latex products and have detectable levels of anti latex IgE.

  19. Process for preparation of large-particle-size monodisperse latexes

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; Micale, F. J.; El-Aasser, M. S.; Kornfeld, D. M. (Inventor)

    1981-01-01

    Monodisperse latexes having a particle size in the range of 2 to 40 microns are prepared by seeded emulsion polymerization in microgravity. A reaction mixture containing smaller monodisperse latex seed particles, predetermined amounts of monomer, emulsifier, initiator, inhibitor and water is placed in a microgravity environment, and polymerization is initiated by heating. The reaction is allowed to continue until the seed particles grow to a predetermined size, and the resulting enlarged particles are then recovered. A plurality of particle-growing steps can be used to reach larger sizes within the stated range, with enlarge particles from the previous steps being used as seed particles for the succeeding steps. Microgravity enables preparation of particles in the stated size range by avoiding gravity related problems of creaming and settling, and flocculation induced by mechanical shear that have precluded their preparation in a normal gravity environment.

  20. Cataract surgery for natural rubber latex allergic patients.

    PubMed

    Cheung, D; Gillow, T

    2003-03-01

    The prevalence of reactions against natural rubber latex (NRL) is thought to be increasing in both the general public and healthcare workers. These can vary from mild benign skin reactions to bronchospasm, anaphylactic shock, and death. Difficulties exist for ophthalmic departments wishing to establish protocols in providing 'latex-free environments' for patients undergoing cataract surgery. Currently no legislation exists regarding the labelling of NRL-containing products in the United Kingdom with information on a product's NRL content provided by the manufacturer on a voluntary basis only. It is hoped this review article will act as a basic guide in the management of NRL-sensitive patients undergoing cataract surgery in the United Kingdom.

  1. Preparing PNNL Reports with LaTeX

    SciTech Connect

    Waichler, Scott R.

    2005-06-01

    LaTeX is a mature document preparation system that is the standard in many scientific and academic workplaces. It has been used extensively by scattered individuals and research groups within PNNL for years, but until now there have been no centralized or lab-focused resources to help authors and editors. PNNL authors and editors can produce correctly formatted PNNL or PNWD reports using the LaTeX document preparation system and the available template files. Please visit the PNNL-LaTeX Project (http://stidev.pnl.gov/resources/latex/, inside the PNNL firewall) for additional information and files. In LaTeX, document content is maintained separately from document structure for the most part. This means that the author can easily produce the same content in different formats and, more importantly, can focus on the content and write it in a plain text file that doesn't go awry, is easily transferable, and won't become obsolete due to software changes. LaTeX produces the finest print quality output; its typesetting is noticeably better than that of MS Word. This is particularly true for mathematics, tables, and other types of special text. Other benefits of LaTeX: easy handling of large numbers of figures and tables; automatic and error-free captioning, citation, cross-referencing, hyperlinking, and indexing; excellent published and online documentation; free or low-cost distributions for Windows/Linux/Unix/Mac OS X. This document serves two purposes: (1) it provides instructions to produce reports formatted to PNNL requirements using LaTeX, and (2) the document itself is in the form of a PNNL report, providing examples of many solved formatting challenges. Authors can use this document or its skeleton version (with formatting examples removed) as the starting point for their own reports. The pnnreport.cls class file and pnnl.bst bibliography style file contain the required formatting specifications for reports to the Department of Energy. Options are also provided for

  2. Durability of styrene-butadiene latex modified concrete

    SciTech Connect

    Shaker, F.A.; El-Dieb, A.S.; Reda, M.M.

    1997-05-01

    The durability of reinforced concrete structures represents a major concern to many investigators. The use of latex modified concrete (LMC) in construction has urged researchers to review and investigate its different properties. This study is part of a comprehensive investigation carried on the use of polymers in concrete. The main objective of this study to investigate and evaluate the main durability aspects of Styrene-Butadiene latex modified concrete (LMC) compared to those of conventional concrete. Also, the main microstructural characteristics of LMC were studied using a Scanning Electron Microscope (SEM). The SEM investigation of the LMC showed major differences in its microstructure compared to that of the conventional concrete. The LMC proved to be superior in its durability compared to the durability of conventional concrete especially its water tightness (measured by water penetration, absorption, and sorptivity tests), abrasion, corrosion, and sulphate resistance.

  3. Film formation and mechanical behavior of polymer latexes

    SciTech Connect

    Gauthier, C.; Sindt, O.; Perez, J.

    1995-12-31

    The purpose of this lecture is to review the present state of the art in the field of film formation in relation with the mechanical behavior of polymer films. After a review of the theoretical approaches concerning film forming process, we show the influence of some experimental parameters (temperature, hygrometry {hor_ellipsis}) in the case of a core-shell latex obtained from polystyrene/Poly (Styrene co. butyl acrylate). Then, the mechanical behavior of polymer films is considered. The improvement of the mechanical strength of latex films during the last stage of film formation (i.e., gradual coalescence) is illustrated. Further analysis of the molecular process yielding mechanical behavior allows us to show how the comparison between prediction and experimental data can provide information on morphological changes, on the stability of this one, or on the formation of an interphase between constituting phases.

  4. Tensile Bond Strength of Latex-Modified Bonded Concrete Overlays

    NASA Astrophysics Data System (ADS)

    Dubois, Cameron; Ramseyer, Chris

    2010-10-01

    The tensile bond strength of bonded concrete overlays was tested using the in-situ pull-off method described in ASTM C 1583 with the goal of determining whether adding latex to the mix design increases bond strength. One slab of ductile concrete (f'c > 12,000 psi) was cast with one half tined, i.e. roughened, and one half steel-troweled, i.e. smooth. The slab surface was sectioned off and overlay mixtures containing different latex contents cast in each section. Partial cores were drilled perpendicular to the surface through the overlay into the substrate. A tensile loading device applied a direct tensile load to each specimen and the load was increased until failure occurred. The tensile bond strength was then calculated for comparison between the specimens.

  5. Graphene-philic surfactants for nanocomposites in latex technology.

    PubMed

    Mohamed, Azmi; Ardyani, Tretya; Bakar, Suriani Abu; Brown, Paul; Hollamby, Martin; Sagisaka, Masanobu; Eastoe, Julian

    2016-04-01

    Graphene is the newest member of the carbon family, and has revolutionized materials science especially in the field of polymer nanocomposites. However, agglomeration and uniform dispersion remains an Achilles' heel (even an elephant in the room), hampering the optimization of this material for practical applications. Chemical functionalization of graphene can overcome these hurdles but is often rather disruptive to the extended pi-conjugation, altering the desired physical and electronic properties. Employing surfactants as stabilizing agents in latex technology circumvents the need for chemical modification allowing for the formation of nanocomposites with retained graphene properties. This article reviews the recent progress in the use of surfactants and polymers to prepare graphene/polymer nanocomposites via latex technology. Of special interest here are surfactant structure-performance relationships, as well as background on the roles surfactant-graphene interactions for promoting stabilization.

  6. A simple optical sensor for the measurement of dry rubber content in natural rubber latex

    NASA Astrophysics Data System (ADS)

    George, Nibu A.; Peethan, Akhila; Vijayan, Midhula

    2013-12-01

    In this article, we report a new method to measure dry rubber content (DRC) in natural latex using a light scattering principle. Latex collected from the field, without diluting or any other chemical processing, can be directly used in this technique to measure its DRC. A laser beam transmitted through a thin column of latex is imaged using a digital camera and the image is processed to calculate the strength of scattering. We have observed a linear relationship between the DRC of the latex and the full width at half of the maximum of the laser beam intensity profile. The method requires only a very small quantity (about 0.5 g) of latex and the measurement is very fast, taking only a few minutes. Although we have demonstrated the described method for latex characterisation, this method can be extended for turbidity/particle concentration measurement of any heavily scattering liquids.

  7. Low prevalence of allergy to cockroach and latex in asthmatic patients in Eskisehir (Anatolia), Turkey.

    PubMed

    Harmanci, E; Metintas, M; Alatas, F; Erginel, S; Mutlu, S

    2000-01-01

    Allergy to cockroach and latex are said to be causes of asthma particularly in some groups. We studied allergy to cockroach and latex in asthmatic patients from Eskisehir (Anatolia), Turkey in order to determine whether these allergens play an important role in the Anatolian region. A total of 216 asthmatic patients (mean age 43.7+/-11.0 years) were skin tested with common aeroallergens, Blatella germanica and latex. Sixty-three patients were allergic (29.1%) and 153 were nonallergic (70.8%) according to skin test results. Sensitization to pollens (57%) and mites (55.5%) was most common among allergic patients. We found a low sensitization to cockroach (4.7%) and latex (1.4%). We suggested that cockroach sensitization plays a small role in sensitization in our geographic area and that latex sensitization is low in allergic asthmatic patients who were referred for reasons other than latex-related symptoms.

  8. Proteomic analysis of latex from the rubber-producing plant Taraxacum brevicorniculatum.

    PubMed

    Wahler, Daniela; Colby, Thomas; Kowalski, Natalie A; Harzen, Anne; Wotzka, Sandra Y; Hillebrand, Andrea; Fischer, Rainer; Helsper, Johannes; Schmidt, Jürgen; Schulze Gronover, Christian; Prüfer, Dirk

    2012-03-01

    Many plants produce latex, a specialized, metabolically active cytoplasm. This is generally regarded as a defensive trait but latex may also possess additional functions. We investigated the role of latex in the dandelion species Taraxacum brevicorniculatum that contains considerable amounts of high-quality natural rubber by carrying out a comprehensive analysis of the latex proteome. We developed reliable protocols for the preparation of protein samples for one-dimensional gel electrophoresis, two-dimensional gel electrophoresis, and subsequent mass spectrometry analysis, which led to 278 unique identifications. A gene ontology classification system based on comparisons with known Arabidopsis thaliana root proteins showed that dandelion proteins involved in lipid metabolism and transport were enriched in the latex proteome, whereas those involved in stress responses were not. We also found that proteins involved in rubber biosynthesis were distributed among different fractions of the latex proteome.

  9. Further insight into the latex metabolite profile of Ficus carica.

    PubMed

    Oliveira, Andreia P; Silva, Luís R; Andrade, Paula B; Valentão, Patrícia; Silva, Branca M; Gonçalves, Rui F; Pereira, José A; Guedes de Pinho, Paula

    2010-10-27

    Latex is a sticky emulsion that exudes upon damage from specialized canals from several plants. It contains several biologically active compounds, such as phytosterols, fatty acids, and amino acids. In plants, these compounds are involved in the interaction between plants, insects, and the environment. Despite its chemical, biological, and ecological importance, Ficus carica latex is still poorly studied. To improve the knowledge on the metabolite profile of this matrix, a targeted metabolite analysis was performed in a representative sample from F. carica latex. Seven phytosterols were determined by gas chromatography-ion trap mass spectrometry (GC-ITMS) and high-performance liquid chromatography coupled to diode array detection (HPLC-DAD), with β-sitosterol and lupeol being the compounds present in higher concentrations (ca. 54 and 14%, respectively). A total of 18 fatty acids were characterized by GC-ITMS, being essentially represented by saturated fatty acids (ca. 86.4% of total fatty acids). A total of 13 free amino acids were also identified by high-performance liquid chromatography coupled to ultraviolet-visible spectroscopy (HPLC/UV-vis), and cysteine and tyrosine were the major ones (ca. 38.7 and 31.4%, respectively). In humans, phytosterols and some polyunsaturated fatty acids, such as linoleic acid, are known for their anticarcinogenic properties. With regard to amino acids, some of them, such as glycine, are neurotransmitters. Our results reveal the presence of a wide diversity of compounds, from distinct classes, in F. carica latex, possessing various potential pharmacological activities; thus, its biological potential appears to be worth further exploring.

  10. Latex Admixtures for Portland Cement Concrete and Mortar

    DTIC Science & Technology

    1986-07-01

    REPAIR, EVALUATION, MAINTENANCE, AND REHABILITATION RESEARCH PROGRAM TECHNICAL REPORT REMR-CS-3 LATEX ?uJIV11XTURES t-OR PORTLAND CEMENT CONCRETE ...designating technical reports of research published under the Repair, Evaluation, Maintenance, and Rehabilitation (REMR) Research Program identify the...problem area under which the report was prepared: cs GT HY Problem Area Concrete and Steel Structures Geotechnical Hydraulics EM El OM Problem

  11. Extractable proteins from irradiated field natural rubber latex

    NASA Astrophysics Data System (ADS)

    Rogero, Sizue O.; Lugão, Ademar B.; Yoshii, Fumio; Makuuchi, Keizo

    2003-06-01

    In this study field natural rubber latex was irradiated with different doses near a 60Co gamma source to reduce the water-soluble protein content in the final product. The protein content of the films obtained by casting method was extracted with phosphate buffer solution, pH 7 and was measured using Micro BCA Protein Assay kit. Also was measured protein in the serum samples of field NRL. The concentration of extractable proteins increased with increasing radiation dose.

  12. Therapeutic effects of fig tree latex on bovine papillomatosis.

    PubMed

    Hemmatzadeh, F; Fatemi, A; Amini, F

    2003-12-01

    The effects of fig tree latex in treating teat papillomatosis in cow in comparison with salicylic acid were evaluated. For this purpose, 12 cows of 1-3 years of age (average 2.25) affected by teat papillomatosis were divided into three groups. In group A, four cows were treated by fig tree (Ficus carica) latex; in group B, four cows were treated with 10% salicylic acid solution and in group C, four cows were kept as control animals receiving no treatment. Animals in each treatment group received their treatment once every 5 days. In groups A and B, de-epithelialization and shrinking of the warts began from the fifth day of treatment and all the warts disappeared within 30 days. However, in the control group no changes in the number of warts were observed until day 15 but thereafter a number of warts disappeared spontaneously in some of the animals. Both salicylic acid and fig tree latex were evaluated as having similar therapeutic effects in treating teat papillomatosis in cow.

  13. Biocompatibility of natural latex implanted into dental alveolus of rats.

    PubMed

    Balabanian, Cláudia A C A; Coutinho-Netto, Joaquim; Lamano-Carvalho, Teresa L; Lacerda, Suzie A; Brentegani, Luiz G

    2006-12-01

    The present study investigated the biocompatibility of a biopolymer based on vegetable latex extracted from the Hevea brasiliensis rubber tree, implanted into the bony alveolar cavity after dental extraction in rats. A granule of latex (area = 0.25 +/- 0.04 mm(2)) was implanted inside the alveolus immediately after extraction of the upper right incisor, and the animals were sacrificed 7, 21 and 42 days after the procedure. The hemi-maxillas were decalcified and processed for embedding in paraffin to obtain semi-serial longitudinal sections 5 mum thick, and then stained with hematoxylin-eosin. The latex granule was observed in the cervical third of the alveolus without any foreign body reaction, or persistence of the initial acute inflammatory reaction. Bone repair in the areas adjacent to the material was quantified, and a decrease was noted in the thickness of the fibrous capsule surrounding the implants from 92.8 +/- 9.3 microm on day 7 to 9.4 +/- 1.8 microm on day 42 (ANOVA, P = 0.01). The quantitative data confirmed acceleration of bone formation (statistically significant at 5%) in parallel with a decrease of connective tissue in the areas around the implants. These results show that the tested material is biologically compatible, and progressively integrated into the alveolar bone, simultaneously accelerating bone formation and playing an important role in the healing process.

  14. Cytotoxic cardenolides from the latex of Calotropis procera.

    PubMed

    Mohamed, Nadia H; Liu, Miaomiao; Abdel-Mageed, Wael M; Alwahibi, Lamya H; Dai, Huanqin; Ismail, Mady Ahmed; Badr, Gamal; Quinn, Ronald J; Liu, Xueting; Zhang, Lixin; Shoreit, Ahmed A M

    2015-10-15

    Three new cardenolides (3, 9 and 10), along with eight known ones, were isolated from the latex of Calotropis procera. The structural determination was accomplished by the 1D- and 2D-NMR spectra as well as HRESIMS analysis. The growth inhibitory activity of the latex and its sub-fractions as well as isolated compounds was evaluated against human A549 and Hela cell lines. The results exhibited that latex had strong growth inhibitory activity with IC50s of (3.37 μM, A-549) and (6.45 μM, Hela). Among the four extracts (hexane, chloroform, ethyl acetate and aqueous), chloroform extract displayed the highest potential cytotoxic activity, with IC50s of (0.985 μM, A-549) and (1.471 μM, Hela). All the isolated compounds displayed various degrees of cytotoxic activity and the highest activity was observed by calactin (1) with IC50s values of (0.036 μM, A-549) and (0.083 μM, Hela). None of these isolated compounds exhibited good antimicrobial activity evaluated by determination of their MICs using the broth microdilution method against various infectious pathogens. The structure-activity relationships for cytotoxic activity were also discussed.

  15. Extractable proteins from field radiation vulcanized natural rubber latex

    NASA Astrophysics Data System (ADS)

    Parra, Duclerc F.; Pinto Martins, Carlos Felipe; Collantes, Chirinos H. D.; Lugao, Ademar B.

    2005-07-01

    The type I allergy associated with the use of natural rubber latex (NRL) products is caused by the NRL proteins leached by the sweat or other body fluids. Makuuchi's group proposed for the first time the proteins removal by the addition of water-soluble polymers (WSP) on radiation vulcanization of natural rubber latex (RVNRL) that is a promising process under development in many countries. In this study, Brazilian field natural rubber was irradiated with a 60Co gamma source to reduce the content of WSP in the final product. WSP was used as additive to improve the extraction of protein. After irradiation the RVNRL was centrifuged to extract the WSP and proteins. The analytical methodology for protein content was based on the modified Lowry method according to ASTM D5712. Protein determination was carried out in serum of latex and in the extracts of the gloves. The concentration of extractable water-soluble proteins in serum of irradiated field NRL (NRL1), not irradiated one (NRL2); of twice centrifuged sample with polymer additive NRL (NRL3) and of the glove manufactured (NRLG) are compared with commercial glove (CG). The irradiation process increases the extractable water-soluble proteins, EP, as reported in the literature. In this study the use of polymeric additive on the bi-centrifugation process to remove protein was successful and the EP of the glove obtained in NRL3 was at around 40% of the commercial glove.

  16. Differentiating of cross-reactions in patients with latex allergy with the use of ISAC test

    PubMed Central

    Chełmińska, Marta; Różyło, Anna; Kołakowska, Agata; Jassem, Ewa

    2016-01-01

    Introduction Differentiating between cross-reactivity and double sensitization is still a challenging issue in allergology. Aim To differentiate cross-reactions accompanying latex allergy with the use of the ISAC test. Material and methods Thirty-nine patients reporting immediate allergic reactions to latex were enrolled into the study (group A). The control group was comprised of 41 patients with allergic diseases not associated with latex (group B) and 20 healthy individuals (group C). Their history was recorded and skin prick tests were performed with latex, airborne and food allergens. Specific IgE against food allergens, latex (k82) and recombined latex allergens were determined. ImmunoCAP ISAC test was performed with 103 molecules. Results Sensitization to latex was found by means of skin tests in 16 cases and sIgE against latex was revealed in 12 cases (including 10 positive in both SPT and sIgE). In the ISAC test antibodies against recombined latex allergens were found in 8 patients with rHev b 6 as the most common. All the patients positive for rHev b 1, 5, 6, 8 had allergy or asymptomatic sensitization to food allergens cross-reacting with latex. Some reactions could not have been differentiated due to the lack of allergens in the ISAC test. Others, not related to latex-fruits syndrome were explained by cross-reactivity with other profilins or PR-10 proteins. Conclusions ImmunoCAP ISAC test could be useful in differentiating between cross-reactions and double sensitizations. However, in the case of latex its advantages are limited due to a small panel of allergens. PMID:27279821

  17. Comprehensive Proteomics Analysis of Laticifer Latex Reveals New Insights into Ethylene Stimulation of Natural Rubber Production

    PubMed Central

    Wang, Xuchu; Wang, Dan; Sun, Yong; Yang, Qian; Chang, Lili; Wang, Limin; Meng, Xueru; Huang, Qixing; Jin, Xiang; Tong, Zheng

    2015-01-01

    Ethylene is a stimulant to increase natural rubber latex. After ethylene application, both fresh yield and dry matter of latex are substantially improved. Moreover, we found that ethylene improves the generation of small rubber particles. However, most genes involved in rubber biosynthesis are inhibited by exogenous ethylene. Therefore, we conducted a proteomics analysis of ethylene-stimulated rubber latex, and identified 287 abundant proteins as well as 143 ethylene responsive latex proteins (ERLPs) with mass spectrometry from the 2-DE and DIGE gels, respectively. In addition, more than 1,600 proteins, including 404 ERLPs, were identified by iTRAQ. Functional classification of ERLPs revealed that enzymes involved in post-translational modification, carbohydrate metabolism, hydrolase activity, and kinase activity were overrepresented. Some enzymes for rubber particle aggregation were inhibited to prolong latex flow, and thus finally improved latex production. Phosphoproteomics analysis identified 59 differential phosphoproteins; notably, specific isoforms of rubber elongation factor and small rubber particle protein that were phosphorylated mainly at serine residues. This post-translational modification and isoform-specific phosphorylation might be important for ethylene-stimulated latex production. These results not only deepen our understanding of the rubber latex proteome but also provide new insights into the use of ethylene to stimulate rubber latex production. PMID:26348427

  18. Latex-specific proteins causing immediate-type cutaneous, nasal, bronchial, and systemic reactions.

    PubMed

    Jaeger, D; Kleinhans, D; Czuppon, A B; Baur, X

    1992-03-01

    We examined 70 patients reporting hypersensitivity reactions caused by latex articles. All patients suffered from urticaria, 36 from rhinitis, 31 from conjunctivitis, 22 from dyspnea, and 17 from systemic reactions, and four patients developed severe systemic complications during surgery. By means of inhalative challenge tests with powdered latex gloves, it could be demonstrated that the glove powder (cornstarch) obviously functions as a carrier for latex allergens, which then become airborne. Five of 18 patients undergoing such challenge tests demonstrated a significant increase of specific airway resistance; 17, acute rhinitis and/or conjunctivitis; and two, a systemic reaction. Sixty-two percent of the patients demonstrated specific IgE antibodies to natural latex, 58% to an irradiatively cross-linked, so-called, "hypoallergenic" latex preparation, and 46% to commercial-latex RAST disks (Pharmacia). No specific antibodies to cornstarch or a mixture of rubber chemicals were found. A good correlation (82%) exists between latex IgE RAST and latex skin prick test, as revealed in a subgroup of 45 subjects. By means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the latex allergen appears to be a mixture of proteins in a molecular weight range from 10 to 67 kd.

  19. [Recurrent effusion and granulomatous synovitis following total knee arthroplasty in association with latex allergy].

    PubMed

    Schuh, A; Thomas, P; Hönle, W; Schmickal, T

    2008-02-01

    An increasing number of articles report about allergic reactions in association with total knee arthroplasty. While most studies focus on allergic reactions to metallic components, few reports exist about reactions to bone cement or its ingredients. Allergy to natural rubber latex is a major occupational problem in the health care sector and a problem even in other occupations in which protective gloves are used. The allergic reaction to latex ranges from a minor skin rash to anaphylactic shock. Preventing exposure to latex is the key to managing and preventing this allergy. We report about a patient who developed recurrent effusion and granulomatous synovitis following total knee arthroplasty in association with latex allergy.

  20. Physiological changes and molluscicidal effects of crude latex and Milin on Biomphalaria glabrata.

    PubMed

    Yadav, Subhash C; Jagannadham, M V

    2008-04-01

    Euphorbian latex is commonly used as molluscicides and the Euphorbia milii latex was reported as most powerful molluscicidal agents. The physiological and lethal effects of the latex components of Euphorbia milii, on the intermediate host Biomphalaria spp., of the human liver parasite Schistosoma mansoni were described in this study. The standard methodologies for testing plant derived molluscicides formulated by World Health Organisation (WHO) were followed with some modifications. The young specimen of fresh water snails showed altered physiological and physical response towards latex components. The working concentration of non-proteinaceous fraction (up to 0.1%) of the latex reduced the active physiological behaviour but was non-lethal to young specimen of snails. However, proteinaceous fractions (0.1mg/l) of the latex were found lethal to snail population, and lethality was enhanced with small amount of the non-proteinaceous fraction (0.01%) of the latex. Milin, a serine protease(up to 0.1mg/l), isolated from the latex of Euphorbia milii significantly reduced the growth and feeding activity but was not lethal to young specimen of snails. With an addition of 0.01% of non-proteinaceous fractions to Milin, lethality result was similar to that of crude latex. Milin is likely to be responsible for alteration of normal physiological functions and lethality of snails, thus it may be used as a molluscicide to control transmission of the endemic disease schistosomiasis.

  1. Effects of the Papaya meleira virus on papaya latex structure and composition.

    PubMed

    Rodrigues, Silas P; Da Cunha, Maura; Ventura, José A; Fernandes, Patricia Machado Bueno

    2009-05-01

    Spontaneous latex exudation is the main symptom of papaya sticky (meleira) disease caused by the Papaya meleira virus (PMeV), a double-stranded RNA (dsRNA) virus. This paper describes different effects of PMeV on papaya latex. Latex samples were subjected to different histochemical tests to evaluate their chemical composition. Additionally, the integrity of the latex particles was assessed by transmission and scanning electron microscopy analysis. Biochemical and micro- and macro-element measurements were performed. PMeV dsRNA extraction was performed to evaluate the interaction of the virus with the latex particles. Sticky diseased latex was positive for alkaloid biosynthesis and showed an accumulation of calcium oxalate crystals. PMeV also increased H(2)O(2) synthesis within sticky diseased laticifers. The protein, sugar and water levels were altered, probably due to chemical changes. The morphology of the latex particles was further altered; PMeV particles seemed to be bound to the latex particles. The alkaloid and H(2)O(2) biosynthesis in the papaya laticifers indicate a papaya defense response against PMeV. However, such efforts failed, as the virus affected the plant latex. The effects described here suggest some advantages of the infection process, including facilitating the movement of the virus within the papaya plant.

  2. Minimizing latex exposure and allergy. How to avoid or reduce sensitization in the healthcare setting.

    PubMed

    Muller, Barbara A

    2003-04-01

    Healthcare professionals with long-term exposure to natural rubber latex products and patients who undergo multiple operations are at high risk for latex allergy. The clinical spectrum of this allergy ranges from self-limited contact urticaria to involvement of multiple organ systems in anaphylaxis. In this article, Dr Muller explores the roots of the latex allergy epidemic and offers insight into the manufacturing process of latex gloves. She also presents a clinical approach to prevent or ameliorate sensitization and manage allergic symptoms.

  3. A case of anaphylactic shock attributed to latex allergy during gastric cancer surgery

    PubMed Central

    Lee, Woohyung; Lee, Jue Hee; Kim, Hyung-Ho

    2011-01-01

    Latex allergy is a known cause of allergic contact dermatitis. It produces mild symptoms, including skin rash and itching, which usually subside in a few days. However, latex allergy can also induce anaphylaxis, a severe type I hypersensitivity reaction that can cause urticaria, angioedema, hypotension, tachycardia, and bronchospasm. We report a case of anaphylactic shock during gastric cancer surgery in a patient with no previous allergic history. Surgery was suspended when hypotension, tachycardia, and wheezing developed. A thorough workup revealed that the patient had a latex allergy. The patient subsequently underwent curative gastrectomy performed with latex-free procedures. PMID:22319734

  4. Evaluation of cytotoxicity and genotoxicity of Hancornia speciosa latex in Allium cepa root model.

    PubMed

    Ribeiro, T P; Sousa, T R; Arruda, A S; Peixoto, N; Gonçalves, P J; Almeida, L M

    2016-02-01

    The latex obtained from Hancornia speciosa Gomes (Mangabeira tree) is widely used in traditional medicine to treat a variety of diseases, including diarrhea, ulcer, gastritis, tuberculosis, acne and warts. In this study, the cytotoxicity and genotoxicity effects of H. speciosa latex on the root meristem cells of Allium cepa were examined. Onion bulbs were exposed to different concentrations of latex and then submitted to microscopic analysis using Giemsa stain. Water was used as a negative control and sodium azide as a positive control. The results showed that, under the testing conditions, the mitotic index (MI) of the onion roots submitted to latex treatment did not differ significantly from the negative control, which suggests that the latex is not cytotoxic. Low incidence of chromosome aberrations in the cells treated with H. speciosa latex was also observed, indicating that the latex does not have genotoxic effect either. The MI and the chromosome aberration frequency responded to the latex concentration, requiring more studies to evaluate the dosage effect on genotoxicity. The results indicate that in tested concentrations H. speciosa latex is probably not harmful to human health and may be potentially used in medicine.

  5. Comprehensive Proteomics Analysis of Laticifer Latex Reveals New Insights into Ethylene Stimulation of Natural Rubber Production.

    PubMed

    Wang, Xuchu; Wang, Dan; Sun, Yong; Yang, Qian; Chang, Lili; Wang, Limin; Meng, Xueru; Huang, Qixing; Jin, Xiang; Tong, Zheng

    2015-09-08

    Ethylene is a stimulant to increase natural rubber latex. After ethylene application, both fresh yield and dry matter of latex are substantially improved. Moreover, we found that ethylene improves the generation of small rubber particles. However, most genes involved in rubber biosynthesis are inhibited by exogenous ethylene. Therefore, we conducted a proteomics analysis of ethylene-stimulated rubber latex, and identified 287 abundant proteins as well as 143 ethylene responsive latex proteins (ERLPs) with mass spectrometry from the 2-DE and DIGE gels, respectively. In addition, more than 1,600 proteins, including 404 ERLPs, were identified by iTRAQ. Functional classification of ERLPs revealed that enzymes involved in post-translational modification, carbohydrate metabolism, hydrolase activity, and kinase activity were overrepresented. Some enzymes for rubber particle aggregation were inhibited to prolong latex flow, and thus finally improved latex production. Phosphoproteomics analysis identified 59 differential phosphoproteins; notably, specific isoforms of rubber elongation factor and small rubber particle protein that were phosphorylated mainly at serine residues. This post-translational modification and isoform-specific phosphorylation might be important for ethylene-stimulated latex production. These results not only deepen our understanding of the rubber latex proteome but also provide new insights into the use of ethylene to stimulate rubber latex production.

  6. Rapid detection of hemagglutination using restrictive microfluidic channels equipped with waveguide-mode sensors

    NASA Astrophysics Data System (ADS)

    Ashiba, Hiroki; Fujimaki, Makoto; Awazu, Koichi; Fu, Mengying; Ohki, Yoshimichi; Tanaka, Torahiko; Makishima, Makoto

    2016-02-01

    Hemagglutination is utilized for various immunological assays, including blood typing and virus detection. Herein, we describe a method of rapid hemagglutination detection based on a microfluidic channel installed on an optical waveguide-mode sensor. Human blood samples mixed with hemagglutinating antibodies associated with different blood groups were injected into the microfluidic channel, and reflectance spectra of the samples were measured after stopping the flow. The agglutinated and nonagglutinated samples were distinguishable by the alterations in their reflectance spectra with time; the microfluidic channels worked as spatial restraints for agglutinated red blood cells. The demonstrated system allowed rapid hemagglutination detection within 1 min. The suitable height of the channels was also discussed.

  7. Correlating particle deformation with water concentration profiles during latex film formation: reasons that softer latex films take longer to dry.

    PubMed

    Carter, Farai T; Kowalczyk, Radoslaw M; Millichamp, Ian; Chainey, Malcolm; Keddie, Joseph L

    2014-08-19

    During the past two decades, an improved understanding of the operative particle deformation mechanisms during latex film formation has been gained. For a particular colloidal dispersion, the Routh-Russel deformation maps predict the dominant mechanism for particle deformation under a particular set of conditions (evaporation rate, temperature, and initial film thickness). Although qualitative tests of the Routh-Russel model have been reported previously, a systematic study of the relationship between the film-formation conditions and the resulting water concentration profiles is lacking. Here, the water distributions during the film formation of a series of acrylic copolymer latexes with varying glass-transition temperatures, Tg (values of -22, -11, 4, and 19 °C), have been obtained using GARField nuclear magnetic resonance profiling. A significant reduction in the rate of water loss from the latex copolymer with the lowest Tg was found, which is explained by its relatively low polymer viscosity enabling the growth of a coalesced skin layer. The set of processing parameters where the drying first becomes impeded occurs at the boundary between the capillary deformation and the wet sintering regimes of the Routh-Russel model, which provides strong confirmation of the model's validity. An inverse correlation between the model's dimensionless control parameter and the dimensionless drying time is discovered, which is useful for the design of fast-drying waterborne films.

  8. Nanoscale Mineralogy and Composition of Experimental Regolith Agglutinates Produced under Asteroidal Impact Conditions

    NASA Technical Reports Server (NTRS)

    Christoffersen, Roy; Cintala, M. J.; Keller, L. P.; See, T. H.; Horz, F.

    2013-01-01

    On the Moon, the energetics of smaller impactors and the physical/chemical characteristics of the granular regolith target combine to form a key product of lunar space weathering: chemically reduced shock melts containing optically-active nanophase Fe metal grains (npFe0) [1]. In addition to forming the optically dark glassy matrix phase in lunar agglutinitic soil particles [1], these shock melts are becoming increasingly recognized for their contribution to optically active patina coatings on a wide range of exposed rock and grain surfaces in the lunar regolith [2]. In applying the lessons of lunar space weathering to asteroids, the potential similarities and differences in regolith-hosted shock melts on the Moon compared to those on asteroids has become a topic of increasing interest [3,4]. In a series of impact experiments performed at velocities applicable to the asteroid belt [5], Horz et al. [6] and See and Horz [7] have previously shown that repeated impacts into a gabbroic regolith analog target can produce melt-welded grain aggregates morphologically very similar to lunar agglutinates [6,7]. Although these agglutinate-like particles were extensively analyzed by electron microprobe and scanning electron microscopy (SEM) as part of the original study [7], a microstructural and compositional comparison of these aggregates to lunar soil agglutinates at sub-micron scales has yet to be made. To close this gap, we characterized a representative set of these aggregates using a JEOL 7600 field-emission scanning electron microscope (FE-SEM), and JEOL 2500SE field-emission scanning transmission electron microscope (FE-STEM) both optimized for energy dispersive X-ray spectroscopy (EDX) compositional spectrum imaging at respective analytical spatial resolutions of 0.5 to 1 micron, and 2 to 4 nm.

  9. pH-responsive aqueous foams stabilized by hairy latex particles.

    PubMed

    Fujii, Syuji; Mochizuki, Michiru; Aono, Kodai; Hamasaki, Sho; Murakami, Ryo; Nakamura, Yoshinobu

    2011-11-01

    Polystyrene (PS) latex particles carrying pH-responsive poly[2-(diethylamino)ethyl methacrylate] (PDEA) hair (PDEA-PS particles) were synthesized by dispersion polymerization and characterized in terms of diameter, diameter distribution, morphology, chemical composition, surface chemistry, and pH-response using scanning electron microscopy (SEM), elemental microanalysis, (1)H nuclear magnetic resonance spectroscopy, the laser diffraction method, and zeta potential measurements. The hairy particles can act as pH-responsive stabilizers of aqueous foams by adsorption at the air-water surface. Above pH 8.0, where particles have nonprotonated PDEA hair, which is relatively hydrophobic, particle-stabilized foams are stable for at least 1 month. Optical microscopy and SEM confirmed that flocculated PDEA-PS latex particles were adsorbed at the air-water interface and stabilized the aqueous foams. At pH 6.1 and 7.1, relatively stable foams can be prepared that remain stable for at least 24 h. SEM studies indicated that the PDEA-PS particles were adsorbed at the air-water interface as a monolayer at pH 6.1. At pH 5.1 and 3.1, where the particles have cationic water-soluble PDEA hairs with hydrophilic character, no foam was formed. Rapid defoamation can be induced by lowering the solution pH; the addition of acid caused the in situ protonation of 2-(diethylamino)ethyl methacrylate residues, which impart water-soluble hydrophilic character to the PDEA hair, and the PDEA-PS particles desorbed from the air-water interface. The foaming and defoaming cycles could be repeated at least five times.

  10. Antibodies to spermatozoa. I. A new macroscopic agglutination technique for their detection, using immotile sperm

    PubMed Central

    Shulman, S.; Hekman, Annemarie

    1971-01-01

    An agglutination procedure, especially useful for guinea-pig sperm, has been developed. The preferred conditions are as follows: epididymal spermatozoa, in an immotile condition, unwashed or diluted and centrifuged once, at a concentration of 10×106 per ml diluted in phosphate-buffered saline, are incubated with antiserum samples in capillary tubes at 4°C for 1 or 2 hr of observation. This procedure has readily allowed us to detect the presence of antibodies against epididymal spermatozoa. The test has given results that are quite parallel to those obtained by the conventional Kibrick method. ImagesFig. 1Fig. 2 PMID:5570676

  11. Latex Allergies: A Review of Recognition, Evaluation, Management, Prevention, Education, and Alternative Product Use

    PubMed Central

    Schroyer, Traci; Catalfano, Jennifer

    2003-01-01

    Objectives: To provide information about latex allergies; to determine how to recognize, evaluate, and manage emergencies related to latex allergies; and how to identify those at risk for latex allergies. Additionally, ways to prevent latex exposure, to educate health care workers and athletes about latex allergy, and to provide safe alternatives to latex are investigated. Data Sources: We searched MEDLINE and SPORT Discus for the years 1998–2002 using the key words latex, allergies, rubber, anaphylaxis, gloves, cross-reaction, IgE (immunoglobulin G) proteins, and radioallergosorbent test (RAST). Background: Latex, a sap from the rubber tree, is found in many products used in everyday life. Latex is composed of compounds that may cause an allergic reaction, whose severity can range from irritant dermatitis to type IV dermatitis to type I systemic reaction. Recognition of the signs and symptoms associated with these reactions by the health care professional may help to prevent a more severe reaction from occurring. Reactions can be complicated by contact with other substances, thus causing a cross-reaction. Some individuals are more at risk of latex allergies due to repetitive exposure to latex through their career paths, multiple surgeries, other allergies, or respiratory conditions. Management of an acute reaction involves removal of the irritant, cleansing of the affected area, monitoring vital signs for changes, and seeking additional medical assistance as warranted. Recommendations: Those at risk may be identified through a thorough medical history and allergy testing. Prevention techniques and guidelines are examined, with an emphasis on education at multiple levels. Product information for nonlatex equipment and supplies for the athletic training room is offered, with additional resource information provided. PMID:16558678

  12. Latex Hypersensitivity among Allergic Egyptian Children: Relation to Parental/Self Reports

    PubMed Central

    El-Sayed, Zeinab A.; El-Sayed, Shereen S.; Zaki, Rehab M.; Salama, Mervat A.

    2014-01-01

    Background. Latex allergy is one of the major health concerns and allergic reactions to latex may be serious and fatal. Purpose. In this study, we sought to determine the frequency of latex hypersensitivity in a group of allergic Egyptian infants and children and its relation to the history provided by the patients or caregivers. Methods. We consecutively enrolled 400 patients with physician diagnosed allergic diseases. The study measurements included clinical evaluation for the site and duration of allergy, history suggestive of latex allergy, family history of allergy, and skin prick testing (SPT) using a commercial latex extract. Results. The study revealed that 16/400 (4%) patients had positive SPT; 11 of them only had positive history of sensitivity to latex. Positive latex SPT was reported in 3.4% (11/326) of patients with bronchial asthma, 5.9% (7/118) of patients with skin allergy, and 4.5% (2/44) of patients with allergic rhinitis. SPT was positive in 7.4% (4/54) of patients with concomitant respiratory and skin allergy. Latex SPT was more specific than sensitive (97.69% and 77.77%, resp.) with a negative predictive value of 99.47%. Conclusion. Although underrecognized, latex is an important allergen in the pediatric age group with a sensitization frequency of 4% among allergic children. It was observed to be especially associated with multiple allergic diseases coexisting in the same patient. Pediatric allergologists should educate their patients on latex allergy and encourage the use of latex-free products. PMID:25505988

  13. High influx of carbon in walls of agglutinated foraminifers during the Permian-Triassic transition in global oceans

    USGS Publications Warehouse

    Nestell, Galina P.; Nestell, Merlynd K.; Ellwood, Brooks B.; Wardlaw, Bruce R.; Basu, Asish R.; Ghosh, Nilotpal; Phuong Lan, Luu Thi; Rowe, Harry D.; Hunt, Andrew G.; Tomkin, Jonathan H.; Ratcliffe, Kenneth T.

    2015-01-01

    The Permian–Triassic mass extinction is postulated to be related to the rapid volcanism that produced the Siberian flood basalt (Traps). Unrelated volcanic eruptions producing several episodes of ash falls synchronous with the Siberian Traps are found in South China and Australia. Such regional eruptions could have caused wildfires, burning of coal deposits, and the dispersion of coal fly ash. These eruptions introduced a major influx of carbon into the atmosphere and oceans that can be recognized in the wallstructure of foraminiferal tests present in survival populations in the boundary interval strata. Analysis of free specimens of foraminifers recovered from residues of conodont samples taken at aPermian–Triassic boundary section at Lung Cam in northern Vietnam has revealed the presence of a significant amount of elemental carbon, along with oxygen and silica, in their test wall structure, but an absence of calcium carbonate. These foraminifers, identified as Rectocornuspira kalhori, Cornuspira mahajeri, and Earlandia spp. and whose tests previously were considered to be calcareous, are confirmed to be agglutinated, and are now referred to as Ammodiscus kalhori and Hyperammina deformis. Measurement of the 207Pb/204Pb ratios in pyrite clusters attached to the foraminiferal tests confirmed that these tests inherited the Pb in their outer layer from carbon-contaminated seawater. We conclude that the source of the carbon could have been either global coal fly ash or forest fire-dispersed carbon, or a combination of both, that was dispersed into the Palaeo-Tethys Ocean immediately after the end-Permian extinction event.

  14. A Possible Role for Agglutinated Foraminifers in the Growth of Deep-Water Coral Bioherms

    NASA Astrophysics Data System (ADS)

    Messing, C. G.; Reed, J. K.; Brooke, S. D.

    2008-05-01

    Exploration of deep-water bioherms dominated by the scleractinian corals Lophelia pertusa and Enallopsammia profunda along the east coast of Florida in ~400-800 m depth reveals an often dense and rich assemblage of small (~1-30 mm) epifauna on dead coral branches, which is often dominated by agglutinated astrorhizacean foraminifers accompanied by thecate and athecate hydroids, sponges, stylasterids, anemones and barnacles. The dominant agglutinated foraminifer is an arborescent form up to 15 mm tall, consisting of a basal tube that gives rise to branchlets of successively decreasing diameter and thickly coated with fine-grained material including coccoliths and diatom frustules. The large numbers of foraminifers generate an enormous adhesive, sediment-trapping surface area and may represent an important accelerated route for sediment deposition and bioherm growth relative to baffling of suspended sediment particles by the coral branches themselves. These foraminifers also occur on still living coral, suggesting that they may either contribute to coral death or invade stressed colonies. They may thus be responsible for or contribute to the small percent of living corals observed in many of these habitats. Other epifauna appear to colonize after the coral has died.

  15. Comparison of PCR, Wright agglutination test and blood culture for diagnosis of brucellosis in suspected patients.

    PubMed

    Hekmatimoghaddam, Seyedhosssein; Sadeh, Maryam; Khalili, Mohammad Bagher; Mollaabedin, Mansour; Sazmand, Alireza

    2013-11-15

    Brucellosis has long been prevalent in Iran, with considerable medical and economic importance. Timely diagnosis is needed for early management and effective prevention of its consequences in human beings and animals. Current diagnostic methods impose peculiar challenges in terms of analytical method performance. This study compares diagnostic sensitivity, specificity, predictive Value of Positive (PVP) and Predictive Value of Negative (PVN) for Polymerase Chain Reaction (PCR), Wright agglutination test and blood culture used for patients suspected of brucellosis. In 120 patients clinically suspected of brucellosis and referred by physicians to the Yazd central Medical Laboratory, some relevant demographic, occupational, nutritional and clinical data were collected. Also, venous blood samples were drawn for diagnosis of brucellosis using PCR, Wright agglutination test and blood culture techniques. The most frequent symptom of patients was arthralgia (82 cases, 68.3%). PCR was positive in 25 cases (20.8%), wright test in 21 patients (17.5%) and blood culture in 6 cases (5%). In 20 out of 21 wright-positive cases, PCR was positive and all of the culture-positive patients had positive PCR. Sensitivity, specificity, PVP and PVN of blood culture compared to PCR (as the gold standard test) were 24, 100, 100 and 86%, respectively, but the above parameters when PCR is compared with blood culture (as gold standard) were 100, 83, 24 and 95%, respectively. PCR has better analytical performances than blood culture for diagnosis of brucellosis and is suitable for confirmation of Wright-positive cases.

  16. Amyloidogenic amyloid-β-peptide variants induce microbial agglutination and exert antimicrobial activity

    PubMed Central

    Spitzer, Philipp; Condic, Mateja; Herrmann, Martin; Oberstein, Timo Jan; Scharin-Mehlmann, Marina; Gilbert, Daniel F.; Friedrich, Oliver; Grömer, Teja; Kornhuber, Johannes; Lang, Roland; Maler, Juan Manuel

    2016-01-01

    Amyloid-β (Aβ) peptides are the main components of the plaques found in the brains of patients with Alzheimer’s disease. However, Aβ peptides are also detectable in secretory compartments and peripheral blood contains a complex mixture of more than 40 different modified and/or N- and C-terminally truncated Aβ peptides. Recently, anti-infective properties of Aβ peptides have been reported. Here, we investigated the interaction of Aβ peptides of different lengths with various bacterial strains and the yeast Candida albicans. The amyloidogenic peptides Aβ1-42, Aβ2-42, and Aβ3p-42 but not the non-amyloidogenic peptides Aβ1-40 and Aβ2-40 bound to microbial surfaces. As observed by immunocytochemistry, scanning electron microscopy and Gram staining, treatment of several bacterial strains and Candida albicans with Aβ peptide variants ending at position 42 (Aβx-42) caused the formation of large agglutinates. These aggregates were not detected after incubation with Aβx-40. Furthermore, Aβx-42 exerted an antimicrobial activity on all tested pathogens, killing up to 80% of microorganisms within 6 h. Aβ1-40 only had a moderate antimicrobial activity against C. albicans. Agglutination of Aβ1-42 was accelerated in the presence of microorganisms. These data demonstrate that the amyloidogenic Aβx-42 variants have antimicrobial activity and may therefore act as antimicrobial peptides in the immune system. PMID:27624303

  17. High Bacterial Agglutination Activity in a Single-CRD C-Type Lectin from Spodoptera exigua (Lepidoptera: Noctuidae)

    PubMed Central

    Gasmi, Leila; Ferré, Juan; Herrero, Salvador

    2017-01-01

    Lectins are carbohydrate-interacting proteins that play a pivotal role in multiple physiological and developmental aspects of all organisms. They can specifically interact with different bacterial and viral pathogens through carbohydrate-recognition domains (CRD). In addition, lectins are also of biotechnological interest because of their potential use as biosensors for capturing and identifying bacterial species. In this work, three C-type lectins from the Lepidoptera Spodoptera exigua were produced as recombinant proteins and their bacterial agglutination properties were characterized. The lowest protein concentration producing bacterial agglutination against a panel of different Gram+ and Gram− as well as their carbohydrate binding specificities was determined for the three lectins. One of these lectins, BLL2, was able to agglutinate cells from a broad range of bacterial species at an extremely low concentration, becoming a very interesting protein to be used as a biosensor or for other biotechnological applications involving bacterial capture. PMID:28257054

  18. High Bacterial Agglutination Activity in a Single-CRD C-Type Lectin from Spodoptera exigua (Lepidoptera: Noctuidae).

    PubMed

    Gasmi, Leila; Ferré, Juan; Herrero, Salvador

    2017-03-01

    Lectins are carbohydrate-interacting proteins that play a pivotal role in multiple physiological and developmental aspects of all organisms. They can specifically interact with different bacterial and viral pathogens through carbohydrate-recognition domains (CRD). In addition, lectins are also of biotechnological interest because of their potential use as biosensors for capturing and identifying bacterial species. In this work, three C-type lectins from the Lepidoptera Spodoptera exigua were produced as recombinant proteins and their bacterial agglutination properties were characterized. The lowest protein concentration producing bacterial agglutination against a panel of different Gram+ and Gram- as well as their carbohydrate binding specificities was determined for the three lectins. One of these lectins, BLL2, was able to agglutinate cells from a broad range of bacterial species at an extremely low concentration, becoming a very interesting protein to be used as a biosensor or for other biotechnological applications involving bacterial capture.

  19. Efficacy and phytochemical analysis of latex of Calotropis procera against selected dermatophytes

    PubMed Central

    Aliyu, Rabiu Muhammad; Abubakar, Mikaeel Bala; Kasarawa, Adamu Bello; Dabai, Yakubu Umar; Lawal, Nafiu; Bello, Muhammad Bashir; Fardami, Aminu Yusuf

    2015-01-01

    Background: Since ancient time, increased interest has been witnessed in the use of an alternative herbal medicine for managing, and the treatment of fungal diseases worldwide. This may be connected to the cost and relative toxicities of the available antifungal drugs. It has been a known tradition practiced in the northern part of Nigeria that parents and teachers use the white latex of Calotropis procera to treat Tinea capitis in children attending the local religious school in the area. This study was conducted in 2009 to ascertain the above claim. Materials and Methods: Fresh latex of C. procera was screened for their antifungal activity against species of dermatophytes: Trichophyton spp., Microsporum spp. and Epidermophyton spp. using the agar incorporation method. Results: The result shows that the latex inhibits the in vitro growth of these pathogenic fungi to varying extents with Trichophyton spp. being the most susceptible (P < 0.05) and thus highly inhibited by the latex followed by the Microsporum spp. and Epidermopyton spp. was least inhibited. These inhibitions followed a dose-dependent trend as undiluted latex (100%) gave the highest inhibitory impacts (P < 0.05) when compared to serially diluted latex. The phytochemical analysis of the fresh latex indicated the presence of alkaloids, saponin, tannins, steroids, flavonoids, anthraquinone, and triterpenoids. Conclusion: The findings of this study confirmed the perceived usefulness of the latex in the treatment of T. capitis (ringworm) practiced in our society and therefore, its use topically in the treatment of dermatomycotic infection is encouraged. PMID:26649237

  20. Involvement of Ethylene in the Latex Metabolism and Tapping Panel Dryness of Hevea brasiliensis

    PubMed Central

    Putranto, Riza-Arief; Herlinawati, Eva; Rio, Maryannick; Leclercq, Julie; Piyatrakul, Piyanuch; Gohet, Eric; Sanier, Christine; Oktavia, Fetrina; Pirrello, Julien; Kuswanhadi; Montoro, Pascal

    2015-01-01

    Ethephon, an ethylene releaser, is used to stimulate latex production in Hevea brasiliensis. Ethylene induces many functions in latex cells including the production of reactive oxygen species (ROS). The accumulation of ROS is responsible for the coagulation of rubber particles in latex cells, resulting in the partial or complete stoppage of latex flow. This study set out to assess biochemical and histological changes as well as changes in gene expression in latex and phloem tissues from trees grown under various harvesting systems. The Tapping Panel Dryness (TPD) susceptibility of Hevea clones was found to be related to some biochemical parameters, such as low sucrose and high inorganic phosphorus contents. A high tapping frequency and ethephon stimulation induced early TPD occurrence in a high latex metabolism clone and late occurrence in a low latex metabolism clone. TPD-affected trees had smaller number of laticifer vessels compared to healthy trees, suggesting a modification of cambial activity. The differential transcript abundance was observed for twenty-seven candidate genes related to TPD occurrence in latex and phloem tissues for ROS-scavenging, ethylene biosynthesis and signalling genes. The predicted function for some Ethylene Response Factor genes suggested that these candidate genes should play an important role in regulating susceptibility to TPD. PMID:26247941

  1. Hancornia speciosa latex for biomedical applications: physical and chemical properties, biocompatibility assessment and angiogenic activity.

    PubMed

    Almeida, Luciane Madureira; Floriano, Juliana Ferreira; Ribeiro, Thuanne Pires; Magno, Lais Nogueira; da Mota, Lígia Souza Lima Silveira; Peixoto, Nei; Mrué, Fátima; Melo-Reis, Paulo; Lino Junior, Ruy de Souza; Graeff, Carlos Frederico de Oliveira; Gonçalves, Pablo José

    2014-09-01

    The latex obtained from Hancornia speciosa is used in folk medicine for treatment of several diseases, such as acne, warts, diabetes, gastritis and inflammation. In this work, we describe the biocompatibility assessment and angiogenic properties of H. speciosa latex and its potential application in medicine. The physical-chemical characterization was carried out following different methodologies (CHN elemental analyses; thermogravimetric analyses and Fourier transform infrared spectroscopy). The biocompatibility was evaluated through cytotoxicity and genotoxicity tests in fibroblast mouse cells and the angiogenic properties were evaluated using the chick chorioallantoic membrane (CAM) assay model. The physical-chemical results showed that the structure of Hancornia speciosa latex biomembrane is very similar to that of Hevea brasiliensis (commercially available product). Moreover, the cytotoxicity and genotoxicity assays showed that H. speciosa latex is biocompatible with life systems and can be a good biomaterial for medical applications. The CAM test showed the efficient ability of H. speciosa latex in neovascularization of tissues. The histological analysis was in accordance with the results obtained in the CAM assay. Our data indicate that the latex obtained from H. speciosa and eluted in water showed significant angiogenic activity without any cytotoxic or genotoxic effects on life systems. The same did not occur with H. speciosa latex stabilized with ammonia. Addition of ammonia does not have significant effects on the structure of biomembranes, but showed a smaller cell survival and a significant genotoxicity effect. This study contributes to the understanding of the potentialities of H. speciosa latex as a source of new phytomedicines.

  2. [Predisposition to latex allergy undetected on preoperative evaluation: a case report].

    PubMed

    Kimura, Yuriko; Okamura, Makoto; Harioka, Tokuya; Hara, Tadashi; Kamiya, Kiyoshi; Matsukawa, Takashi

    2013-12-01

    A 70-year-old man was scheduled to undergo laparoscopic total gastrectomy for stomach cancer. He had no history of atopy, fruit allergies, or frequent exposure to natural rubber. Preoperative latex-specific IgE antibodies were negative. Anesthesia was induced, and the surgery was started uneventfully. Soon after the surgeon had begun to manipulate the intestine, the blood pressure suddenly dropped to 27/21 mmHg. Facial flushing was also observed. Anaphylactic shock caused by latex was strongly suspected, and surgery was immediately halted. The surgical gloves were changed to latex-free ones, and adrenaline was administered. The blood pressure was gradually normalized within 30 min, and the facial flushing mostly disappeared. Postoperative laboratory examination revealed that serum tryptase had increased to 34.4 microg l-1, 40 minutes after the onset of anaphylaxis, and decreased to 19.4 microg l-1, 24 hours than later. Latex-specific IgE antibodies and a prick test with latex were both positive. Consequently, the diagnosis of latex-induced anaphylactic reaction was confirmed. Because even detailed questioning and examination does not always identify such a predisposition, avoiding contactwith latex products is more rational exhaustively checking every preoperative patient for latex allergy

  3. Latex allergy symptoms among health care workers: results from a university health and safety surveillance system.

    PubMed

    Epling, Carol; Duncan, Jacqueline; Archibong, Emma; Østbye, Truls; Pompeii, Lisa A; Dement, John

    2011-01-01

    We sought to describe risk factors for latex glove allergy symptoms among health care workers by combining data from an active clinical surveillance program and a comprehensive occupational health surveillance system. A total of 4,584 employers completed a latex allergy questionnaire. Six percent (n = 276) of subjects reported symptoms consistent with latex allergy. Years of latex glove use was a significant risk factor for latex allergy symptoms even after controlling for the effects of atopy, gender, age, race, fruit, and other allergies. Nurses, medical or lab technicians, physician's assistants, other clinical professionals, and housekeepers had the highest prevalence of latex glove allergy symptoms. Forty subjects (0.87%) who were confirmed as having latex sensitization. Sensitizsation may have been underestimated due to use of specific IgE antibody, less sensitive than skin-prick testing, and tiered design leading to laboratory assessment on a subset of the cohort. This surveillance program identified risk factors for latex allergy symptoms. Our findings provide a basis for tailoring future prevention strategies.

  4. Industrial-hygiene survey report of Dow Chemical USA SB (styrene butadiene) Latex Facility, Freeport, Texas

    SciTech Connect

    Fajen, J.M.; Krishnan, E.R.

    1986-03-01

    The purpose of the survey was to obtain information on the SB latex production process and assess the potential for occupational exposure to 1,3-butadiene at the SB latex facility. The information will be used in determining the suitability of including the plant in an in-depth survey.

  5. Involvement of Ethylene in the Latex Metabolism and Tapping Panel Dryness of Hevea brasiliensis.

    PubMed

    Putranto, Riza-Arief; Herlinawati, Eva; Rio, Maryannick; Leclercq, Julie; Piyatrakul, Piyanuch; Gohet, Eric; Sanier, Christine; Oktavia, Fetrina; Pirrello, Julien; Kuswanhadi; Montoro, Pascal

    2015-08-04

    Ethephon, an ethylene releaser, is used to stimulate latex production in Hevea brasiliensis. Ethylene induces many functions in latex cells including the production of reactive oxygen species (ROS). The accumulation of ROS is responsible for the coagulation of rubber particles in latex cells, resulting in the partial or complete stoppage of latex flow. This study set out to assess biochemical and histological changes as well as changes in gene expression in latex and phloem tissues from trees grown under various harvesting systems. The Tapping Panel Dryness (TPD) susceptibility of Hevea clones was found to be related to some biochemical parameters, such as low sucrose and high inorganic phosphorus contents. A high tapping frequency and ethephon stimulation induced early TPD occurrence in a high latex metabolism clone and late occurrence in a low latex metabolism clone. TPD-affected trees had smaller number of laticifer vessels compared to healthy trees, suggesting a modification of cambial activity. The differential transcript abundance was observed for twenty-seven candidate genes related to TPD occurrence in latex and phloem tissues for ROS-scavenging, ethylene biosynthesis and signalling genes. The predicted function for some Ethylene Response Factor genes suggested that these candidate genes should play an important role in regulating susceptibility to TPD.

  6. Banded cucumber beetle (Coleoptera: Chrysomelidae) resistance in romaine lettuce: understanding latex chemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many plants subjected to herbivore damage exude latex, a rich source of biochemicals, which play important roles in host plant resistance. Our previous studies showed that fresh latex from Valmaine, a resistant cultivar of romaine lettuce Lactuca sativa L., applied to artificial diet is highly deter...

  7. VOLATILE ORGANIC COMPOUND EMISSIONS FROM LATEX PAINT - PART 1. CHAMBER EXPERIMENTS AND SOURCE MODEL DEVELOPMENT

    EPA Science Inventory

    Latex paints are widely used in residential and commercial indoor environments. The surface areas covered by the paints in these environments are relatively large. Thus, latex paints have the potential for having a major impact on indoor air quality (IAQ). A study was undertaken ...

  8. 40 CFR 428.110 - Applicability; description of the latex foam subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... latex foam subcategory. 428.110 Section 428.110 Protection of Environment ENVIRONMENTAL PROTECTION... Foam Subcategory § 428.110 Applicability; description of the latex foam subcategory. The provisions of... foam except for those discharges from textile plants subject to the provisions of part 410 of...

  9. Synthesis and Characterization of Core-Shell Acrylate Based Latex and Study of Its Reactive Blends

    PubMed Central

    Liu, Xiang; Fan, Xiao-Dong; Tang, Min-Feng; Nie, Ying

    2008-01-01

    Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) and glycidyl methacrylate (GMA) as monomers and ammonium persulfate and sodium bisulfite redox system as the initiator. Two stages seeded semi-continuous emulsion polymerization were employed for constructing a core-shell structure with P(MMA-co-BA) component as the core and P(EHA-co-GMA) component as the shell. Results of Transmission Electron Microscopy (TEM) and Dynamics Light Scattering (DLS) tests confirmed that the particles obtained are indeed possessing a desired core-shell structural character. Stable reactive latex blends were prepared by adding the latex with waterborne melamine-formaldehyde resin (MF) or urea-formaldehyde resin (UF). It was found that the glass transition temperature, the mechanical strength and the hygroscopic property of films cast from the latex blends present marked enhancements under higher thermal treatment temperature. It was revealed that the physical properties of chemically reactive latexes with core-shell structure could be altered via the change of crosslinking density both from the addition of crosslinkers and the thermal treatment. PMID:19325753

  10. Polymer composites prepared from heat-treated starch and styrene-butadiene latex

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermoplastic starch/latex polymer composites were prepared using styrene–butadiene (SB) latex and heat-treated cornstarch. The composites were prepared in a compression mold at 130 °C, with starch content 20%. An amylose-free cornstarch, waxy maize, was used for this research and the heat treatment...

  11. A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack.

    PubMed

    Huber, Meret; Epping, Janina; Schulze Gronover, Christian; Fricke, Julia; Aziz, Zohra; Brillatz, Théo; Swyers, Michael; Köllner, Tobias G; Vogel, Heiko; Hammerbacher, Almuth; Triebwasser-Freese, Daniella; Robert, Christelle A M; Verhoeven, Koen; Preite, Veronica; Gershenzon, Jonathan; Erb, Matthias

    2016-01-01

    Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha), and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground.

  12. A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack

    PubMed Central

    Huber, Meret; Epping, Janina; Schulze Gronover, Christian; Fricke, Julia; Aziz, Zohra; Brillatz, Théo; Swyers, Michael; Köllner, Tobias G.; Vogel, Heiko; Hammerbacher, Almuth; Triebwasser-Freese, Daniella; Robert, Christelle A. M.; Verhoeven, Koen; Preite, Veronica; Gershenzon, Jonathan; Erb, Matthias

    2016-01-01

    Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha), and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground. PMID:26731567

  13. Restriction-Site-Specific PCR as a Rapid Test To Detect Enterohemorrhagic Escherichia coli O157:H7 Strains in Environmental Samples

    PubMed Central

    Kimura, Richard; Mandrell, Robert E.; Galland, John C.; Hyatt, Doreene; Riley, Lee W.

    2000-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important food-borne pathogen in industrialized countries. We developed a rapid and simple test for detecting E. coli O157:H7 using a method based on restriction site polymorphisms. Restriction-site-specific PCR (RSS-PCR) involves the amplification of DNA fragments using primers based on specific restriction enzyme recognition sequences, without the use of endonucleases, to generate a set of amplicons that yield “fingerprint” patterns when resolved electrophoretically on an agarose gel. The method was evaluated in a blinded study of E. coli isolates obtained from environmental samples collected at beef cattle feedyards. The 54 isolates were all initially identified by a commonly used polyclonal antibody test as belonging to O157:H7 serotype. They were retested by anti-O157 and anti-H7 monoclonal antibody enzyme-linked immunosorbent assay (ELISA). The RSS-PCR method identified all 28 isolates that were shown to be E. coli O157:H7 by the monoclonal antibody ELISA as belonging to the O157:H7 serotype. Of the remaining 26 ELISA-confirmed non-O157:H7 strains, the method classified 25 strains as non-O157:H7. The specificity of the RSS-PCR results correlated better with the monoclonal antibody ELISA than with the polyclonal antibody latex agglutination tests. The RSS-PCR method may be a useful test to distinguish E. coli O157:H7 from a large number of E. coli isolates from environmental samples. PMID:10831431

  14. Rapid detection of group A streptococci: comparative performance by nurses and laboratory technologists in pediatric satellite laboratories using three test kits.

    PubMed Central

    Donatelli, J; Macone, A; Goldmann, D A; Poon, R; Hinberg, I; Nanji, A; Thorne, G M

    1992-01-01

    Rapid tests for detecting group A streptococci in throat swabs are often performed outside hospitals or commercial laboratories by individuals with little or no technical training. We compared the abilities of nurses and technologists to perform and interpret three commercial kits (Directigen 1-2-3, ICON Strep A, and Culturette Brand 10-Minute Strep A ID) in three hospital satellite locations (the emergency department, a walk-in emergency clinic, and a general pediatric clinic). When the three tests were compared with culture, the sensitivities of the tests as performed by nurses and technologists, respectively, were 39 versus 44% for Directigen, 55 versus 51% for Culturette, and 72 versus 39% for ICON. A significant difference in sensitivity was found only with ICON tests. This result was largely explained by the tendency of technologists to test moist swabs, while nurses generally processed dry swabs; ICON test sensitivity was significantly greater with dry swabs. The specificities of Directigen and ICON tests performed by nurses and technologists were high (97 to 100%). The difference in the specificities of the Culturette test as determined from results obtained by nurses and technologists (80 versus 98%) was due to the tendency of one nurse to overinterpret the latex agglutination reaction. Analysis of the accuracies of the tests during practice periods compared with the accuracies of the tests during the study periods revealed statistically significant improvement in test performance. We conclude that these tests are specific but not sensitive when performed by nurses and technologists in satellite laboratories. With one exception, nurses and technologists performed the tests with comparable accuracy after brief training periods. PMID:1734045

  15. Poly(styrene/alpha-tert-butoxy-omega-vinylbenzylpolyglycidol) microspheres for immunodiagnostics. Principle of a novel latex test based on combined electrophoretic mobility and particle aggregation measurements.

    PubMed

    Radomska-Galant, Izabela; Basinska, Teresa

    2003-01-01

    The principle of a novel latex agglutination test based on combined results of electrophoretic mobility and particle aggregation measurements is described. Poly(styrene/alpha-tert-butoxy-omega-vinylbenzylpolyglycidol) (P(S/PGL)) microspheres were synthesized by a one step soap-free emulsion copolymerization of styrene and alpha-tert-butoxy-omega-vinylbenzylpolyglycidol macromonomer with number average molecular weight Mn = 2700 (polydispersity [Mw]/[Mn] = 1.10). Particles with monomodal size distribution (number average diameter Dn = 220 nm) and surface fraction of polyglycidol equal to f = 0.42 mol % were obtained. Human serum albumin (HSA) was covalently bound onto the surface of P(S/PGL) microspheres activated with 1,3,5-trichlorotriazine. In a model immunodiagnostic assay for anti-HSA, in which P(S/PGL) particles with covalently bound HSA have been used, the electrophoretic mobility and aggregation of microspheres were measured simultaneously. This approach allowed detection of anti-HSA in the serum in the range of anti-HSA concentrations from 0.1 to 150 microg/mL. The highest changes in electrophoretic mobility were registered for microspheres with surface concentration of immobilized HSA equal to Gamma = 9.2 x 10(-4) g/m2.

  16. Suicidal Smothering by Rubber Latex Gloves and Handkerchief.

    PubMed

    Viero, Alessia; Cecchetto, Giovanni; Boscolo-Berto, Rafael; Viel, Guido; Montisci, Massimo

    2016-01-01

    Asphyxial deaths are common in forensic practice, being sustained by a variety of mechanisms that cause an oxygen deficiency to the brain. Several classification models have been proposed in the literature, the most recent one being that of the International Network for Forensic Research Group (INFOR). This report describes an unusual case of suffocation where the obstruction of the airways was caused by a gag formed of three latex gloves and a handkerchief. The manner of death (differential diagnosis between homicide and suicide) and the different alternatives of classification are discussed.

  17. Cytotoxic Orbitide from the Latex of Croton urucurana.

    PubMed

    Cândido-Bacani, Priscila de M; Figueiredo, Patrícia de O; Matos, Maria de F C; Garcez, Fernanda R; Garcez, Walmir S

    2015-11-25

    The bioactive ethyl acetate phase obtained from the latex of Croton urucurana Baillon afforded a novel orbitide (1), [1-9-NαC]-crourorb A1, that proved active against NCI-ADR/RES (ovary, multidrug-resistance phenotype) cells with the same potency as doxorubicin (positive control) and inactive up to the highest concentration tested against nontumor NIH/3T3 cells. The structure elucidation was based on 1D and 2D NMR spectroscopy, further supported by HRESIMS data and by application of Marfey's method for determination of the absolute configuration of its amino acid residues. This is the first orbitide obtained from C. urucurana.

  18. Mobility and surfactant migration in EA/MAA latex films; ATR FT-IR spectroscopic study

    SciTech Connect

    Thorstenson, T.A.; Tebelius, L.K.; Urban, M.W.

    1993-12-31

    Although numerous factors such as compatibility, mechanical deformation, and the nature of the substrate have been addressed with respect to surfactant migration and distribution within latex films, latex suspension stability and the effects of particle flocculation are also key issues. In this paper, surfactant behavior in an ethyl acrylate/methacrylic acid/sodium dioctyl sulfosuccinate (EA/MAA/SDOSS) latex system is monitored as a function of stability of the liquid latex suspensions. Particle size data obtained using light scattering reveals an appreciable degree of flocculation over the period of study. It is found that flocculation is paralleled by a significantly increased degree of interfacial surfactant enrichment, a monitored by attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR). It is concluded that the enhanced surfactant exudation observed for flocculated latexes is due to displacement of adsorbed surfactant during the course of flocculation.

  19. An ESEM investigation of latex film formation in cement pore solution

    SciTech Connect

    Gretz, M.; Plank, J.

    2011-02-15

    Environmental scanning electron microscopy (ESEM) and complementary methods were employed to study the time dependent film formation of a latex dispersion in water and cement pore solution. First, a model carboxylated styrene/n-butyl acrylate latex dispersion possessing a minimum film forming temperature (MFFT) of 18 {sup o}C was synthesized in aqueous media via emulsion polymerization. Its film forming property was at a temperature of 40 {sup o}C, studied under an ESEM. The analysis revealed that upon removal of water, film formation occurs as a result of particle packing, particle deformation and finally particle coalescence. Film formation is significantly retarded when the latex dispersion is present in cement pore solution. This effect can be ascribed to adsorption of Ca{sup 2+} ions onto the surface of the anionic latex particles and to interfacial secondary phases. This layer of adsorbed Ca{sup 2+} ions hinders interdiffusion of the macromolecules and subsequent film formation of the latex polymer.

  20. Monodisperse Latex Reactor (MLR): A materials processing space shuttle mid-deck payload

    NASA Technical Reports Server (NTRS)

    Kornfeld, D. M.

    1985-01-01

    The monodisperse latex reactor experiment has flown five times on the space shuttle, with three more flights currently planned. The objectives of this project is to manufacture, in the microgravity environment of space, large particle-size monodisperse polystyrene latexes in particle sizes larger and more uniform than can be manufactured on Earth. Historically it has been extremely difficult, if not impossible to manufacture in quantity very high quality monodisperse latexes on Earth in particle sizes much above several micrometers in diameter due to buoyancy and sedimentation problems during the polymerization reaction. However the MLR project has succeeded in manufacturing in microgravity monodisperse latex particles as large as 30 micrometers in diameter with a standard deviation of 1.4 percent. It is expected that 100 micrometer particles will have been produced by the completion of the the three remaining flights. These tiny, highly uniform latex microspheres have become the first material to be commercially marketed that was manufactured in space.

  1. Electrochemical genosensor assay using lyophilized gold nanoparticles/latex microsphere label for detection of Vibrio cholerae.

    PubMed

    Liew, Pei Sheng; Lertanantawong, Benchaporn; Lee, Su Yin; Manickam, Ravichandran; Lee, Yook Heng; Surareungchai, Werasak

    2015-07-01

    Vibrio cholerae is a Gram-negative bacterium that causes cholera, a diarrheal disease. Cholera is widespread in poor, under-developed or disaster-hit countries that have poor water sanitation. Hence, a rapid detection method for V. cholerae in the field under these resource-limited settings is required. In this paper, we describe the development of an electrochemical genosensor assay using lyophilized gold nanoparticles/latex microsphere (AuNPs-PSA) reporter label. The reporter label mixture was prepared by lyophilization of AuNPs-PSA-avidin conjugate with different types of stabilizers. The best stabilizer was 5% sorbitol, which was able to preserve the dried conjugate for up to 30 days. Three methods of DNA hybridization were compared and the one-step sandwich hybridization method was chosen as it was fastest and highly specific. The performance of the assay using the lyophilized reagents was comparable to the wet form for detection of 1aM to 1fM of linear target DNA. The assay was highly specific for V. cholerae, with a detection limit of 1fM of PCR products. The ability of the sensor is to detect LAMP products as low as 50ngµl(-1). The novel lyophilized AuNPs-PSA-avidin reporter label with electrochemical genosensor detection could facilitate the rapid on-site detection of V. cholerae.

  2. Micromorphological characterization and label-free quantitation of small rubber particle protein in natural rubber latex.

    PubMed

    Wang, Sai; Liu, Jiahui; Wu, Yanxia; You, Yawen; He, Jingyi; Zhang, Jichuan; Zhang, Liqun; Dong, Yiyang

    2016-04-15

    Commercial natural rubber is traditionally supplied by Hevea brasiliensis, but now there is a big energy problem because of the limited resource and increasing demand. Intensive study of key rubber-related substances is urgently needed for further research of in vitro biosynthesis of natural rubber. Natural rubber is biosynthesized on the surface of rubber particles. A membrane protein called small rubber particle protein (SRPP) is a key protein associated closely with rubber biosynthesis; however, SRPP in different plants has been only qualitatively studied, and there are no quantitative reports so far. In this work, H. brasiliensis was chosen as a model plant. The microscopic distribution of SRPP on the rubber particles during the washing process was investigated by transmission electron microscopy-immunogold labeling. A label-free surface plasmon resonance (SPR) immunosensor was developed to quantify SRPP in H. brasiliensis for the first time. The immunosensor was then used to rapidly detect and analyze SRPP in dandelions and prickly lettuce latex samples. The label-free SPR immunosensor can be a desirable tool for rapid quantitation of the membrane protein SRPP, with excellent assay efficiency, high sensitivity, and high specificity. The method lays the foundation for further study of the functional relationship between SRPP and natural rubber content.

  3. Identification of serum component involved in generation of neo-lectin with agglutinating and phenoloxidase activities in human serum.

    PubMed

    Manikandan, Beulaja; Ramar, Manikandan; Munusamy, Arumugam

    2014-01-01

    Human serum albumin (HSA) was identified as the component involved in generation of neo-lectin molecules with both lectin and phenoloxidase activities. Pronase treated HSA was able to agglutinate hen RBC and oxidize hydroquinone. Sodium dodecyl sulphate (SDS) treated HSA agglutinated both hen and sheep RBC as well as oxidized dopamine. The hemagglutinating activities of pronase/SDS treated HSA observed against hen RBC were dosimetric. The oxidation of pronase/SDS treated HSA with hydroquinone/dopamine, respectively, was inhibitable by inhibitors of phenoloxidase, namely, phenylthiourea and tropolone. Very low concentrations of HSA could generate these humoral neo-lectin molecules.

  4. Microstructure development in latex coatings: High-resolution cryo-scanning electron microscopy

    NASA Astrophysics Data System (ADS)

    Ge, Haiyan

    2005-07-01

    High-resolution cryogenic scanning electron microscopy (Cryo-SEM) was used to investigate microstructure development in drying latex coatings: from a colloidal stable suspension into a coherent strong film by drying. Useful sample preparation artifacts during the freeze-fracture, i.e., pullouts were documented and analyzed. Pullouts indicate both physical properties of latex particles and the drying stages in latex coatings. The mechanism of pullout formation was studied both theoretically and experimentally. Latex coatings must possess satisfactory freeze-thaw stability to avoid problems during transportation and storage in cold winter. The behavior of latex particles during freeze-thaw cycles was visualized by Cryo-SEM. The images indicated that high concentration of polymerizable surfactant in a latex suspension improved its freeze-thaw stability. In film formation, skinning was captured from edge in and top down in coatings of 80nm diameter styrene-butadiene latex particles with exceptional low Tg (-65°C). Effects on skinning of drying conditions and the way the latex was initially stabilized against flocculation were investigated. A skinned pocket was unexpectedly found in the coating. The cause of such a skin around the air bubble was explained by both simple models calculating the dissolution time and force analysis on the particles. The film formation processes in conventional and low volatile organic compound (VOC) latex coatings were compared by time-sectioning Cryo-SEM. Some low-VOC latex coatings were found to dry as fast as conventional ones without deteriorating final good film properties.

  5. Randomized crossover trial comparing the eZ.on plastic condom and a latex condom.

    PubMed

    Cook, L; Nanda, K; Taylor, D

    2001-01-01

    This randomized crossover trial compared the breakage and slippage rates, safety, and acceptability of the recently developed polyurethane bi-directional eZ.on condom with a marketed latex condom. Three hundred sixty couples were asked to use 4 eZ.on condoms and 4 latex condoms. Like several other non-latex condoms tested to date, the eZ.on condom had a higher clinical breakage rate than its latex comparator, while the slippage rates were similar. The clinical breakage rate for the eZ.on condom was 5.6%, compared with 0.9% for the latex condom (difference = 4.76%, with upper 95% confidence bound on the difference = 6.26%). Thus, based on an a priori definition of a 2% clinically acceptable difference, the study failed to conclude equivalence relative to clinical breakage. The complete slippage rate for eZ.on was 1.6%; compared to 0.7% for latex (difference = 0.87%, with upper 95% confidence bound = 1.55%). Thus, based on an a priori definition of a 2% difference we concluded equivalence relative to complete slippage. The safety profile of the eZ.on condom was good and similar to the latex condom. The eZ.on was also found to be easier to don and remove than the latex condom. Although no overall preference existed for either condom, nearly 30%women and men strongly preferred the eZ.on condom to the latex condom. The eZ.on condom may be an acceptable alternative for couples unable or unwilling to use latex condoms.

  6. The influence of aggregation of latex particles on membrane fouling attachments & ultrafiltration performance in ultrafiltration of latex contaminated water and wastewater.

    PubMed

    Abdelrasoul, Amira; Doan, Huu; Lohi, Ali; Cheng, Chil-Hung

    2017-02-01

    The goal of the present study was to investigate the influence of latex particle aggregation on membrane fouling attachments and the ultrafiltration performance of simulated latex effluent using Cetyltrimethyl Ammonium Bromide (CTAB) as a cationic surfactant. Hydrophilic polysulfone and ultrafilic flat heterogeneous membranes, with molecular weight cut off (MWCO) of 60,000 and 100,000, respectively, as well as hydrophobic polyvinylidene difluoride with MWCO of 100,000, were used under a constant flow rate and cross-flow mode in ultrafiltration of latex solution. In addition, a polycarbonate flat membrane with uniform pore size of 0.05μm was likewise used during the experiment. The effects of CTAB on the latex particle size distribution were investigated at various concentrations, different treatment times, and diverse agitation duration times. The effects of CTAB on the zeta potential of membrane surfaces and latex particles were also investigated. The data obtained indicate that the particle size distribution of treated latex effluent experienced significant shifts in the peaks toward a larger size range caused by the aggregation of particles. As a result, the mass of fouling contributing to pore blocking and the irreversible fouling were noticeably reduced. The optimum results occurred in the instance when CTAB was added at the critical micelle concentration of 0.36g/L, for the duration of 10min and with minimal agitation. Notably, a higher stirring rate had an overall negative effect on the membrane fouling minimization.

  7. Preparation of large-particle-size monodisperse latexes in space

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; El-Aasser, M. S.; Micale, F. J.; Sudol, E. D.; Tseng, C. M.; Silwanowicz, A.; Sheu, H. R.; Kornfeld, D. M.

    1986-01-01

    Results are reported of latex sphere polymerization experiments performed on two flights of the Columbia and three flights of the Challenger. The trials were carried out because polymerization of the spheres in space avoids coagulation, nucleation of a new crop of particles, and excessive stirring requirements, and allows growth of spheres larger than 4 microns diam. The Monodisperse Latex Reactor (MLR) held four stirred 100 cc sealed stainless steel cylindrical containers. The mixtures were monitored for the conversion times, volume decreases as spheres formed and the mixture temperature. The spheres were grown from 0.19 micron seeds. Details of the flight preparation efforts are outlined. In flights which did not experience mechanical malfunctions spheres 3-30 microns diam were grown that had noticeably lower size variations than did the ground-based control particles. The 10 micron diam spheres grown on STS-6 were accepted as standard reference material by the NBS and became the first products made in space to be commercially sold on earth; the 30 micron spheres also became NBS standards. The experiments confirmed all projected benefits of producing the spheres in space, as well as provided the opportunity to grow more larger offsize spheres by finishing the growths on earth.

  8. The influence of particle size on latex colloid deposition kinetics

    SciTech Connect

    Litton, G.M.; Olson, T.M.

    1995-12-01

    The influence of particle size on the deposition kinetics of latex colloids in packed-bed columns was investigated in the presence of sodium dodecyl sulfate. Deposition rates, expressed as attachment efficiencies, were determined with 245, 481, and 755 nm carboxyl and 248 and 753 nm sulfate latex microspheres in granular quartz beds as a function of ionic strength. Experiments were performed at pH 10 in the presence of 10{sup -3} M sodium dodecyl sulfate to mask possible hydrophobic regions on the interacting surfaces. The onset of unfavorable filtration conditions and the sensitivity of the experimental attachment efficiencies, {alpha}{sub exp}, to changes in the ionic strength were both particle size dependent. However, both effects were opposite to that predicted by DLVO theory based on the primary interaction energy barrier height. Correlations of {alpha}{sub exp} with the secondary minimum showed that as attachment efficiencies approached 1 the depth of the secondary well increased. These observations suggest that particles may be retained within the secondary minimum even when a primary energy barrier is sufficient to inhibit attachment.

  9. Hydroxyapatite moldable formulation using natural rubber latex as binder.

    PubMed

    Sailaja, G S; Ramesh, P; Varma, H K

    2007-07-01

    A simple but efficient processing method for shaping intricate bioceramic green bodies has been developed by using natural rubber latex as binder. Different shapes of hydroxyapatite Ca10(PO4)6(OH)2 (HAP) were molded from a composite formulation containing wet precipitated HAP, natural rubber latex (NRL), and a stabilizer. On controlled heat treatment followed by sintering, dense shapes of HAP contours were obtained. The thermal degradation profile of HAP-NRL composites shows that NRL degrades slowly without any abrupt exotherm. The results of energy dispersive X-ray analysis together with inductively coupled plasma (ICP) analysis indicate that the inorganic residue of NRL does not contain any heavy element. The sintered density of the samples increased with increased HAP content in the formulation and percentage shrinkage reduced accordingly. On varying the HAP content in the formulation from 35 to 95 wt %, the compositions with 85, 90, 92, and 95 wt % HAP showed better flexural strength in the range 40-54 MPa and a flexural modulus value in the range 36-50 GPa. The fracture morphology, as observed by the scanning electron microscope confirms that with increased HAP content in the formulation the sample microstructure attains higher uniformity. The Vickers microhardness for the samples sintered at two different temperatures (1150 and 1250 degrees C) showed that hardness increases with increase in the sintering temperature with a maximum for the highest HAP loaded formulation.

  10. Identification of a new phospholipase D in Carica papaya latex.

    PubMed

    Abdelkafi, Slim; Abousalham, Abdelkarim; Fendri, Imen; Ogata, Hiroyuki; Barouh, Nathalie; Fouquet, Benjamin; Scheirlinckx, Frantz; Villeneuve, Pierre; Carrière, Frédéric

    2012-05-15

    Phospholipase D (PLD) is a lipolytic enzyme involved in signal transduction, vesicle trafficking and membrane metabolism. It catalyzes the hydrolysis and transphosphatidylation of glycerophospholipids at the terminal phosphodiester bond. The presence of a PLD in the latex of Carica papaya (CpPLD1) was demonstrated by transphosphatidylation of phosphatidylcholine (PtdCho) in the presence of 2% ethanol. Although the protein could not be purified to homogeneity due to its presence in high molecular mass aggregates, a protein band was separated by SDS-PAGE after SDS/chloroform-methanol/TCA-acetone extraction of the latex insoluble fraction. This material was digested with trypsin and the amino acid sequences of the tryptic peptides were determined by micro-LC/ESI/MS/MS. These sequences were used to identify a partial cDNA (723 bp) from expressed sequence tags (ESTs) of C. papaya. Based upon EST sequences, a full-length gene was identified in the genome of C. papaya, with an open reading frame of 2424 bp encoding a protein of 808 amino acid residues, with a theoretical molecular mass of 92.05 kDa. From sequence analysis, CpPLD1 was identified as a PLD belonging to the plant phosphatidylcholine phosphatidohydrolase family.

  11. Specific IgE response to purified and recombinant allergens in latex allergy

    PubMed Central

    Kurup, Viswanath P; Sussman, Gordon L; Yeang, Hoong Y; Elms, Nancy; Breiteneder, Heimo; Arif, Siti AM; Kelly, Kevin J; Bansal, Naveen K; Fink, Jordan N

    2005-01-01

    Background In recent years, allergy to natural rubber latex has emerged as a major allergy among certain occupational groups and patients with underlying diseases. The sensitization and development of latex allergy has been attributed to exposure to products containing residual latex proteins. Although improved manufacturing procedures resulted in a considerable reduction of new cases, the potential risk for some patient groups is still great. In addition the prevalent cross-reactivity of latex proteins with other food allergens poses a major concern. A number of purified allergens and a few commercial kits are currently available, but no concerted effort was undertaken to evaluate them. Methods We studied 11 purified latex allergens, Hev b 1 to Hev b 10, and Hev b 13 along with several crude allergen extracts and two commercial ImmunoCAP assays to evaluate specific IgE antibody in the sera from latex allergic patients and controls. Health care workers and spina bifida patients with clinical symptoms of latex allergy, spina bifida patients without latex allergy, and non-atopic health care workers have been studied. Results The results suggest that Hev b 2, 5, 6, and 13 together identified over 80 percent health care workers with latex allergy, while Hev b 6 along with Hev b 1 or 3 detected specific IgE antibody in all sera studied from patients with spina bifida and latex allergy. The ImmunoCAP results using both Hev b 5 amplified and non-amplified closely agreed with the clinical diagnosis of latex allergy in health care workers and in spina bifida. Conclusion Although the purified allergens and crude extracts reacted diversely with IgE from different patient groups, the results indicated that use of certain combinations of purified recombinant antigens will be useful in commercial kits or in in-house assays for detecting specific IgE antibody in the sera. The results suggest that a combination of Hev b 2, 3, 5, 6, and 13 together detected specific IgE in 80% of

  12. An experimental investigation of agglutinate melting mechanisms - Shocked mixtures of sodium and potassium feldspars

    NASA Technical Reports Server (NTRS)

    Simon, S. B.; Papike, J. J.; Horz, F.; See, T. H.

    1985-01-01

    The results of an experiment designed to test the validity of the model for agglutinate formation involving fusion of the finest fraction or F3 are reported. Impact glasses were formed from various mixes of orthoclase and albite powders, which were used as analogs for soils with chemically constrasting coarse and fine fractions. The results showed that the single most important factor displacing the composition of a small-scale impact melt from the bulk composition of the source regolith is the fractionated composition of the finest soil fraction. Volatile loss and the amount of melting, which in turn are determined by the degree of shock, are also important. As predicted by the model, the lower pressure melts are the most fractionated, and higher pressure is accompanied by increased melting causing glass compositions to approach the bulk. In general, the systematics predicted by the model are observed; the model appears to be valid.

  13. Prevalence of agglutinating antibodies to Toxoplasma gondii and Sarcocystis neurona in beavers (Castor canadensis) from Massachusetts.

    PubMed

    Jordan, Carly N; Kaur, Taranjit; Koenen, Kiana; DeStefano, Stephen; Zajac, Anne M; Lindsay, David S

    2005-10-01

    The present study examined the seroprevalence of Toxoplasma gondii and Sarcocystis neurona in a population of beavers (Castor canadensis) from Massachusetts. Sixty-two blood samples were collected during the field seasons over 3 consecutive years from different animals. Blood was collected onto filter paper and shipped to the Department of Biomedical Sciences, Virginia Tech, Blacksburg, Virginia, for parasite testing. The samples were tested at dilutions of 1:25, 1:50, and 1:100 against each parasite antigen by modified agglutination tests to determine whether antibodies to either parasite were present in the blood. Six of 62 samples (10%) were positive for T. gondii, with 2 samples having titers of 1:25 and 4 having titers of 1:50. Four of 62 samples (6%) were positive for S. neurona, with 2 samples having titers of 1:25 and 2 having titers of 1:50.

  14. [Identification of mosquitoes' human food source by using the co-agglutination technique].

    PubMed

    Castex, M; Fachado, A; Fonte, L

    1997-01-01

    The utilization of a coagglutination technique for the identification of a human source for feeding mosquitoes is described. The dilution of ingested blood samples in filter paper was performed in 2 mL of a sodium chloride solution at 0.85%. It was used a suspension of sensibilized Staphylococcus aureus with rabbit's serum, human plasmatic anti-proteins, and human anti-IgG rabbit's serum discriminated well between human and non human blood. No agglutination was observed with the negative control. This technique proved to be sensitive to identify 100% of the human blood samples taken to the paper 24 hours after the mosquitoes completed their feeding at a temperature of 26 to 28 degrees C. Among mosquitoes fed and collected in the fields the test had a satisfactory result. Therefore, it may be used in routine work in the fields. The results showed the sensitivity and specificity of this method for identifying human blood ingested by mosquitoes.

  15. Prevalence of agglutinating antibodies to Toxoplasma gondii and Sarcocystis neurona in beavers (Castor canadensis) from Massachusetts

    USGS Publications Warehouse

    Jordan, C.N.; Kaur, T.; Koenen, K.; DeStefano, S.; Zajac, A.M.; Lindsay, D.S.

    2005-01-01

    The present study examined the seroprevalence of Toxoplasma gondii and Sarcocystls neurona in a population of beavers (Castor canadensis) from Massachusetts. Sixty-two blood samples were collected during the field seasons over 3 consecutive years from different animals. Blood was collected onto filter paper and shipped to the Department of Biomedical Sciences, Virginia Tech, Blacksburg, Virginia, for parasite testing. The samples were tested at dilutions of 1:25, 1:50, and 1:100 against each parasite antigen by modified agglutination tests to determine whether antibodies to either parasite were present in the blood. Six of 62 samples (10%) were positive for T. gondii, with 2 samples having titers of 1:25 and 4 having titers of 1:50. Four of 62 samples (6%) were positive for S. neurona, with 2 samples having titers of 1:25 and 2 having titers of 1:50. ?? American Society of Pathologists 2005.

  16. Quick serological detection of a cancer biomarker with an agglutinated supramolecular glycoprobe.

    PubMed

    He, Xiao-Peng; Hu, Xi-Le; Jin, Hong-Ying; Gan, Jiemin; Zhu, Huili; Li, Jia; Long, Yi-Tao; Tian, He

    2015-09-01

    While serology represents the forefront technique for cancer diagnosis, current clinical methods for the detection of serum biomarkers have flaws in terms of the need of complicated manipulations, long analytical time, and high cost. Here, we develop a supramolecular glycoprobe for the quick serological detection of a cancer biomarker. The probe formed by agglutination between self-assembled glyco-gold nanoparticles and a lectin shows subtle optical variations upon the competitive recognition of a glycoprotein biomarker secreted by cancer cells, tumor-bearing mice, as well as clinical cancer patients, with no response to a series of controls including the serum of hepatitis patients. This research provides an insight into the development of effective tools for serological diagnosis of cancer.

  17. Studying red blood cell agglutination by measuring electrical and mechanical properties with a double optical tweezers

    NASA Astrophysics Data System (ADS)

    Fontes, Adriana; Fernandes, Heloise P.; de Thomaz, André A.; Barbosa, Luiz C.; Barjas-Castro, Maria L.; Cesar, Carlos L.

    2007-07-01

    The red blood cell (RBC) viscoelastic membrane contains proteins and glycolproteins embedded in, or attached, to a fluid lipid bilayer and are negatively charged, which creates a repulsive electric (zeta) potential between the cells and prevents their aggregation in the blood stream. The basis of the immunohematologic tests is the interaction between antigens and antibodies that causes hemagglutination. The identification of antibodies and antigens is of fundamental importance for the transfusional routine. This agglutination is induced by decreasing the zeta-potential through the introduction of artificial potential substances. This report proposes the use of the optical tweezers to measure the membrane viscosity, the cell adhesion, the zeta-potential and the size of the double layer of charges (CLC) formed around the cell in an electrolytic solution. The adhesion was quantified by slowly displacing two RBCs apart until the disagglutination. The CLC was measured using the force on the bead attached to a single RBC in response to an applied voltage. The zeta-potential was obtained by measuring the terminal velocity after releasing the RBC from the optical trap at the last applied voltage. For the membrane viscosity experiment, we trapped a bead attached to RBCs and measured the force to slide one RBC over the other as a function of the relative velocity. After we tested the methodology, we performed measurements using antibody and potential substances. We observed that this experiment can provide information about cell agglutination that helps to improve the tests usually performed in blood banks. We also believe that this methodology can be applied for measurements of zeta-potentials in other kind of samples.

  18. Red blood cell membrane viscoelasticity, agglutination and zeta potential measurements with double optical tweezers

    NASA Astrophysics Data System (ADS)

    Fontes, Adriana; Fernandes, Heloise P.; Barjas-Castro, Maria L.; de Thomaz, André A.; de Ysasa Pozzo, Liliana; Barbosa, Luiz C.; Cesar, Carlos L.

    2006-02-01

    The red blood cell (RBC) viscoelastic membrane contains proteins and glycolproteins embedded in, or attached, to a fluid lipid bilayer and are negatively charged, which creates a repulsive electric (zeta) potential between the cells and prevents their aggregation in the blood stream. There are techniques, however, to decrease the zeta potential to allow cell agglutination which are the basis of most of the tests of antigen-antibody interactions in blood banks. This report shows the use of a double optical tweezers to measure RBC membrane viscosity, agglutination and zeta potential. In our technique one of the optical tweezers trap a silica bead that binds strongly to a RBC at the end of a RBCs rouleaux and, at the same time, acts as a pico-Newton force transducer, after calibration through its displacement from the equilibrium position. The other optical tweezers trap the RBC at the other end. To measure the membrane viscosity the optical force is measured as a function of the velocity between the RBCs. To measure the adhesion the tweezers are slowly displaced apart until the RBCs disagglutination happens. The RBC zeta potential is measured in two complimentary ways, by the force on the silica bead attached to a single RBC in response to an applied electric field, and the conventional way, by the measurement of terminal velocity of the RBC after released from the optical trap. These two measurements provide information about the RBC charges and, also, electrolytic solution properties. We believe this can improve the methods of diagnosis in blood banks.

  19. Agglutination of Histoplasma capsulatum by IgG Monoclonal Antibodies against Hsp60 Impacts Macrophage Effector Functions▿

    PubMed Central

    Guimarães, Allan Jefferson; Frases, Susana; Pontes, Bruno; de Cerqueira, Mariana Duarte; Rodrigues, Marcio L.; Viana, Nathan Bessa; Nimrichter, Leonardo; Nosanchuk, Joshua Daniel

    2011-01-01

    Histoplasma capsulatum can efficiently survive within macrophages, facilitating H. capsulatum translocation from the lung into the lymphatics and bloodstream. We have recently generated monoclonal antibodies (MAbs) to an H. capsulatum surface-expressed heat shock protein of 60 kDa (Hsp60) that modify disease in a murine histoplasmosis model. Interestingly, the MAbs induced different degrees of yeast cell agglutination in vitro. In the present study, we characterized the agglutination effects of the antibodies to Hsp60 on H. capsulatum yeast cells by light microscopy, flow cytometry, dynamic light scattering, measuring zeta potential, and using optical tweezers. We found that immunoglobulin Gs (IgGs) to Hsp60 cause H. capsulatum aggregation dependent on the (i) concentration of MAbs, (ii) MAb binding constant, and (iii) IgG subclass. Furthermore, infection of macrophages using agglutinates of various sizes after incubation with different Hsp60-binding MAbs induced association to macrophages through distinct cellular receptors and differentially affected macrophage antifungal functions. Hence, the capacity of IgG MAbs to agglutinate H. capsulatum significantly impacted pathogenic mechanisms of H. capsulatum during macrophage infection, and the effect was dependent on the antibody subclass and antigen epitope. PMID:21134968

  20. In vitro antimicrobial activity of four Ficus carica latex fractions against resistant human pathogens (antimicrobial activity of Ficus carica latex).

    PubMed

    Aref, Houda Lazreg; Salah, Karima Bel Hadj; Chaumont, Jean Pierre; Fekih, Abdelwaheb; Aouni, Mahjoub; Said, Khaled

    2010-01-01

    Methanolic, hexanoïc, chloroformic and ethyl acetate extracts of Ficus carica latex were investigated for their in vitro antimicrobial proprieties against five bacteria species and seven strains of fungi. The green fruit latex was collected from Chott Mariam Souse, Middle East coast of Tunisia. The antimicrobial activity of the extracts was evaluated and based respectively on the inhibition zone using the disc-diffusion assay, minimal inhibition concentration (MIC) for bacterial testing and the method by calculating inhibition percentage (I%) for fungi-inhibiting activities. The methanolic extract had no effect against bacteria except for Proteus mirabilis while the ethyl acetate extract had inhibition effect on the multiplication of five bacteria species (Enterococcus fecalis, Citobacter freundei, Pseudomonas aeruginosa, Echerchia coli and Proteus mirabilis). For the opportunist pathogenic yeasts, ethyl acetate and chlorophormic fractions showed a very strong inhibition (100%); methanolic fraction had a total inhibition against Candida albicans (100%) at a concentration of 500 microg/ml and a negative effect against Cryptococcus neoformans. Microsporum canis was strongly inhibited with methanolic extract (75%) and totally with ethyl acetate extract at a concentration of 750 microg/ml. Hexanoïc extract showed medium results.

  1. In vitro antiviral activity of Ficus carica latex against caprine herpesvirus-1.

    PubMed

    Camero, Michele; Marinaro, Mariarosaria; Lovero, Angela; Elia, Gabriella; Losurdo, Michele; Buonavoglia, Canio; Tempesta, Maria

    2014-01-01

    The latex of Ficus carica Linn. (Moraceae) has been shown to possess antiviral properties against some human viruses. To determine the ability of F. carica latex (F-latex) to interfere with the infection of caprine herpesvirus-1 (CpHV-1) in vitro, F-latex was resuspended in culture media containing 1% ethanol and was tested for potential antiviral effects against CpHV-1. Titration of CpHV-1 in the presence or in the absence of F-latex was performed on monolayers of Madin Darby Bovine Kidney (MDBK) cells. Simultaneous addition of F-latex and CpHV-1 to monolayers of MDBK cells resulted in a significant reduction of CpHV-1 titres 3 days post-infection and this effect was comparable to that induced by acyclovir. The study suggests that the F-latex is able to interfere with the replication of CpHV-1 in vitro on MDBK cells and future studies will determine the mechanisms responsible for the observed antiviral activity.

  2. Scanning electron microscopic examination of human pulmonary capillaries using a latex replication method.

    PubMed

    Kendall, M W; Eissmann, E

    1980-03-01

    The human pulmonary microvasculature from the apical bronchopulmonary segment was studied by scanning electron microscopy using latex replicas. The latex replica was composed of a blend of vinyl chloride latexes using a plasticized vinyl chloride copolymer with a vinyl chloride copolymer. The polymerized latex produced a cast of the pulmonary arterial vascular tree, including the capillary patterns, which freely anastomose, thereby draining blood into pulmonary veinules and veins. The latex was injected via a gravity flow system modified from its earlier application in Guinea pig lungs. The apparently normal lungs from two recently deceased humans (dead for 5-6 hours and held in refrigeration) were perfused with heparinized Ringer's solution and subsequently injected with latex. The resulting latex casts of the capillaries revealed a three-dimensional network arranged in irregular vascular rings or ovals. This pattern was most conspicuous in deep and intermediate bronchopulmonary segmental areas. However, the subpleural capillaries produced casts that often terminated blindly, as observed with stereo SEm, suggesting that these vessels may tend to form thrombi more easily as compared with capillaries from other regions of the lung alveoli. The pulmonary arteriolar replicas contained indentations representing endothelial cell nuclei, and the capillary replicas projected oval evaginations that may represent discrete loci or capillary mural attenuations.

  3. Synthesis and characterization of polymer-silica hybrid latexes and sol-gel-derived films

    NASA Astrophysics Data System (ADS)

    Petcu, Cristian; Purcar, Violeta; Ianchiş, Raluca; Spătaru, Cătălin-Ilie; Ghiurea, Marius; Nicolae, Cristian Andi; Stroescu, Hermine; Atanase, Leonard-Ionuţ; Frone, Adriana Nicoleta; Trică, Bogdan; Donescu, Dan

    2016-12-01

    Sol-gel derived organic-inorganic hybrid systems were obtained by applying alkaline-catalyzed co-hydrolysis and copolycondensation reactions of tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), isobutyltriethoxysilane (IBTES), diethoxydimethylsilane (DMDES), and vinyltriethoxysilane (VTES), respectively, into a polymer latex functionalized with vinyltriethoxysilane (VTES). The properties of the latex hybrid materials were analyzed by FTIR, water contact angle, environmental scanning electron microscopy (ESEM), TEM and AFM analysis, respectively. FT-IR spectra confirmed that the chemical structures of the sol-gel derived organic-inorganic materials are changed as function of inorganic precursor and Sisbnd Osbnd Si networks are formed during the co-hydrolysis and copolycondensation reactions. The water contact angle on the sol-gel latex film containing TEOS + VTES increased to 135° ± 2 compared to 65° ± 5 for the blank latex, due VTES incorporation into latex material. TGA curves of hybrid sample modifies against neat polymer, the thermal stability being influenced by the presence of the inorganic partner. ESEM analysis showed that the latex hybrid films prepared with different inorganic precursors were formed and the Si-based polymers were distributed on the surface of the dried sol-gel hybrid films. TEM and AFM photos revealed that the latex emulsion morphology was modified due to the VTES incorporation into system.

  4. Cellulose fibers modified with nano-sized antimicrobial polymer latex for pathogen deactivation.

    PubMed

    Pan, Yuanfeng; Xiao, Huining; Cai, Pingxiong; Colpitts, Meaghan

    2016-01-01

    Antimicrobial cellulose fibers and paper products are of great importance for various applications. In this work, novel core-shell antimicrobial latexes based on hydrophobic acrylate monomers and antimicrobial macromonomer (GPHGH) were successfully prepared via a seeded semi-continuous emulsion copolymerization in the presence of a cationic surfactant. The surface properties as well as size of latex were tailored by varying the amount of GPHGH incorporated during the copolymerization. The resulting cationic nano-sized latexes showed the strong adsorption and formed monolayer on the surfaces of bleached sulfite fibers, thus rendering the cellulose fibers antimicrobial. An excellent antimicrobial activity (>99.99% inhibition) of modified fiber toward Escherichia coli was achieved at 0.3wt% of latex dosage (on dry fibers). Results of transmission electron microscopy (TEM) observation confirmed that the particles obtained indeed possessed a desired core-shell structure. The latexes themselves exhibited high antimicrobial activities against E. coli with the minimum inhibitory concentration (MIC) as low as 6.25ppm (similar to that of pure guanidine-based polymer). Moreover, the mechanical strength of the hand-sheets made from latex-modified cellulose fibers was also improved due to the filming of the latex on fiber surfaces.

  5. The physical and degradation properties of starch-graft-acrylonitrile/carboxylated nitrile butadiene rubber latex films.

    PubMed

    Misman, M A; Azura, A R; Hamid, Z A A

    2015-09-05

    Starch-graft-acrylonitrile (ANS) is compounded with carboxylated nitrile butadiene rubber (XNBR) latex. The control XNBR and the ANS/XNBR latex films were prepared through a coagulant dipping process. The films were subjected to ageing and soil burial procedures. For the biodegradation experiment, the surface of the film was assessed after the 2nd, 4th and 8th week of soil burial. The ANS, XNBR, and ANS/XNBR colloidal stability were determined with a Malvern Zetasizer. For the dipped latex films, the mechanical, morphological and thermal properties were analyzed. The addition of ANS into the XNBR latex increased the stability of the colloidal dispersions, decreased the latex film tensile strength, but increased the elongation at break due to the bipolar interaction of the ANS and XNBR particles. The ANS/XNBR latex films aged faster than the control films while the morphological analysis showed the existence of a starch crystal region and the formation of microbial colonies on the surfaces of the films. Based on the TGA-DTA curves, a higher ΔT was observed for the ANS/XNBR latex films signifying high thermal energy needed for the film to thermally degrade.

  6. Plant latex: a promising antifungal agent for post harvest disease control.

    PubMed

    Sibi, G; Wadhavan, Rashmi; Singh, Sneha; Shukla, Abhilasha; Dhananjaya, K; Ravikumar, K R; Mallesha, H

    2013-12-01

    Bioactive compounds from plant latex are potential source of antifungic against post harvest pathogens. Latex from a total of seven plant species was investigated for its phytochemical and antifungal properties. Six fungi namely Aspergillus fumigatus, A. niger, A. terreus, F. solani, P. digitatum and R. arrhizus were isolated from infected fruits and vegetables and tested against various solvent extracts of latex. Analysis of latex extracts with phytochemical tests showed the presence of alkaloids, flavonoids, glycosides, phenols, saponins, steroids, tannins and terpenoids. Antifungal assay revealed the potential inhibitory activity of petroleum ether extracts against the postharvest fungal isolates. Various degree of sensitivity was observed irrespective of plant species studied with A. terreus and P. digitatum as the most susceptible ones. F. solani and A. fumigatus were moderately sensitive to the latex extracts tested. Among the plants, latex of Thevetia peruviana (75.2%) and Artocarpus heterophyllus (64.8%) were having potential antifungal activity against the isolates followed by Manilkara zapota (51.1%). In conclusion, use of plant latex makes interest to control postharvest fungal diseases and is fitting well with the concept of safety for human health and environment.

  7. Solid state NMR and LVSEM studies on the hardening of latex modified tile mortar systems

    SciTech Connect

    Rottstegge, J.; Arnold, M.; Herschke, L.; Glasser, G.; Wilhelm, M.; Spiess, H.W. . E-mail: spiess@mpip-mainz.mpg.de; Hergeth, W.D.

    2005-12-15

    Construction mortars contain a broad variety of both inorganic and organic additives beside the cement powder. Here we present a study of tile mortar systems based on portland cement, quartz, methyl cellulose and different latex additives. As known, the methyl cellulose stabilizes the freshly prepared cement paste, the latex additive enhances final hydrophobicity, flexibility and adhesion. Measurements were performed by solid state nuclear magnetic resonance (NMR) and low voltage scanning electron microscopy (LVSEM) to probe the influence of the latex additives on the hydration, hardening and the final tile mortar properties. While solid state NMR enables monitoring of the bulk composition, scanning electron microscopy affords visualization of particles and textures with respect to their shape and the distribution of the different phases. Within the alkaline cement paste, the poly(vinyl acetate) (VAc)-based latex dispersions stabilized by poly(vinyl alcohol) (PVA) were found to be relatively stable against hydrolysis. The influence of the combined organic additives methyl cellulose, poly(vinyl alcohol) and latexes stabilized by poly(vinyl alcohol) on the final silicate structure of the cement hydration products is small. But even small amounts of additives result in an increased ratio of ettringite to monosulfate within the final hydrated tile mortar as monitored by {sup 27}Al NMR. The latex was found to be adsorbed to the inorganic surfaces, acting as glue to the inorganic components. For similar latex water interfaces built up by poly(vinyl alcohol), a variation in the latex polymer composition results in modified organic textures. In addition to the networks of the inorganic cement and of the latex, there is a weak network build up by thin polymer fibers, most probably originating from poly(vinyl alcohol). Besides the weak network, polymer fibers form well-ordered textures covering inorganic crystals such as portlandite.

  8. Sucrose importation into laticifers of Hevea brasiliensis, in relation to ethylene stimulation of latex production

    PubMed Central

    Dusotoit-Coucaud, Anaïs; Brunel, Nicole; Kongsawadworakul, Panida; Viboonjun, Unchera; Lacointe, André; Julien, Jean-Louis; Chrestin, Hervé; Sakr, Soulaïman

    2009-01-01

    Background and Aims The major economic product of Hevea brasiliensis is a rubber-containing cytoplasm (latex), which flows out of laticifers (latex cells) when the bark is tapped. The latex yield is stimulated by ethylene. Sucrose, the unique precursor of rubber synthesis, must cross the plasma membrane through specific sucrose transporters before being metabolized in the laticifers. The relative importance of sucrose transporters in determining latex yield is unknown. Here, the effects of ethylene (by application of Ethrel®) on sucrose transporter gene expression in the inner bark tissues and latex cells of H. brasiliensis are described. Methods Experiments, including cloning sucrose transporters, real time RT-PCR and in situ hybridization, were carried out on virgin (untapped) trees, treated or untreated with the latex yield stimulant Ethrel. Key Results Seven putative full-length cDNAs of sucrose transporters were cloned from a latex-specific cDNA library. These transporters belong to all SUT (sucrose transporter) groups and differ by their basal gene expression in latex and inner soft bark, with a predominance of HbSUT1A and HbSUT1B. Of these sucrose transporters, only HbSUT1A and HbSUT2A were distinctly increased by ethylene. Moreover, this increase was shown to be specific to laticifers and to ethylene application. Conclusion The data and all previous information on sucrose transport show that HbSUT1A and HbSUT2A are related to the increase in sucrose import into laticifers, required for the stimulation of latex yield by ethylene in virgin trees. PMID:19567416

  9. Bioactivity of certain medicinal latexes used by the Ese'ejas.

    PubMed

    Mongelli, E; Desmarchelier, C; Giulietti, A; Coussio, J; Ciccia, G

    1995-07-28

    Latexes from Croton erythrochilus, Ficus inspidia and Sapium marmieri used traditionally as medicinal by the Ese'ejas were analyzed for bioactivity. The assays run were: the brine shrimp toxicity microplate bioassay, the wheat rootlet growth inhibition and the DNA-methyl green bioassay. The three latexes showed cytotoxicity to the brine shrimp and concentration-related growth inhibition. No interaction with the DNA-methyl green complex was observed with any of the three latex samples. The field bioassays described has demonstrated to be useful for supporting ethnobotanical information.

  10. Spherical vesicles distorted by a grafted latex bead: An exact solution

    SciTech Connect

    Benoit, Jerome; Saxena, Avadh

    2007-10-15

    We present an exact solution to the problem of the global shape description of a spherical vesicle distorted by a grafted latex bead. This solution is derived by treating the nonlinearity in bending elasticity through the (topological) Bogomol'nyi decomposition technique and elastic compatibility. We recover the 'hat-model' approximation in the limit of a small latex bead and find that the region antipodal to the grafted latex bead flattens. We also derive the appropriate shape equation using the variational principle and relevant constraints.

  11. Obstetrical and gynecological devices; designation of special controls for male condoms made of natural rubber latex.

    PubMed

    2008-11-10

    The Food and Drug Administration (FDA) is amending the classification regulation for condoms to designate a special control for male condoms made of natural rubber latex (latex). The special control for the device is the guidance document entitled "Class II Special Controls Guidance Document: Labeling for Natural Rubber Latex Condoms Classified Under 21 CFR 884.5300." The FDA will publish a notice in the Federal Register announcing the availability of the special control guidance document no later than the effective date of this final rule.

  12. Latex-modified grouts for in-situ stabilization of buried transuranic/mixed waste

    SciTech Connect

    Allan, M.L.

    1996-06-01

    The Department of Applied Science at Brookhaven national Laboratory was requested to investigate latex-modified grouts for in-situ stabilization of buried TRU/mixed waste for INEL. The waste exists in shallow trenches that were backfilled with soil. The objective was to formulate latex-modified grouts for use with the jet grouting technique to enable in-situ stabilization of buried waste. The stabilized waste was either to be left in place or retrieved for further processing. Grouting prior to retrieval reduces the potential release of contaminants. Rheological properties of latex-modified grouts were investigated and compared with those of conventional neat cement grouts used for jet grouting.

  13. The relationship between film formation and anti-corrosive properties of latex polymers

    SciTech Connect

    Satguru, R.; Padget, J.C.

    1995-12-31

    The emphasis of the paper would be to demonstrate the importance of coherent film formation to derive superior anti-corrosive coatings. The principles of film formation of solvent borne polymer in comparison with waterborne dispersed polymer will be discussed. Two examples of latex polymers will then be presented highlighting the influence of additives such as surfactant and coalescing agent on the film formation process. The examples will include a chloropolymer latex and a styrene-acrylic polymer latex. Results from Electron Microscopy, Atomic Force Microscopy, Moisture Vapour Transmission Measurement, A/C Impedance Measurement, Hot Salt Spray Performance, etc. will be presented.

  14. Effect of solvent annealing on the tensile deformation mechanism of a colloidal crystalline polymeric latex film.

    PubMed

    Zhang, Jianqi; Yi, Zhiyong; Wang, Qiao; Liu, Zhenyu; Perlich, Jan; Gehrke, Rainer; Men, Yongfeng

    2011-10-04

    The influence of solvent annealing on microscopic deformational behavior of a styrene/n-butyl acrylate copolymer latex film subjected to uniaxial tensile deformation was studied by small-angle X-ray scattering. It was demonstrated that the microscopic deformation mechanism of the latex films transformed from a nonaffine deformation behavior to an affine deformation behavior after solvent annealing. This was attributed to the interdiffusion of polymeric chains between adjacent swollen latex particles in the film. It turns out that solvent annealing is much more efficient than thermal annealing due to a much slow evaporation process after solvent annealing.

  15. Angiogenic activity of latex from Euphorbia tirucalli Linnaeus 1753 (Plantae, Euphorbiaceae).

    PubMed

    Bessa, G; Melo-Reis, P R; Araújo, L A; Mrué, F; Freitas, G B; Brandão, M L; Silva Júnior, N J

    2015-08-01

    To assess the pro-angiogenic activity of Euphorbia tirucalli, commonly known as "avelós" plant, we performed a series of tests by applying an aqueous E. tirucalli latex solution (10 mg/mL) to the chorioallantoic membranes (CAMs) of 80 fertilized chicken eggs incubated in a temperature- and humidity-controlled automatic incubator. The results indicated that the aqueous latex solution increased vascular network formation compared to that with the negative control (p < 0.05) and the inhibitor control (p < 0.05). This suggests that under the experimental conditions tested, the aqueous latex solution induced an inflammatory response leading to neoangiogenesis.

  16. [The diagnosis of cryptococcosis. A comparison of 2 latex systems for antigen detection].

    PubMed

    Alvarez Bernal, L P; Martínez Machín, G; Fernández Andreu, C; Llop Hernández, A

    1992-01-01

    A latex reactive was designed for detecting Cryptococcus neoformans antigen. It was evaluated by a comparative study with a commercial system (Meridian Diagnostic, Inc.). Total coincidence was observed with both latex systems after studying 3 sample groups: patients with cryptococcosis diagnosis, blood bank donors and patients with clinical signs of the disease. Sensitivity, specificity and stability of the latex reactives prepared were assessed. This diagnostic technique opens new perspectives for quick diagnosis in Cuba, especially for immunosuppressed patients. It will allow for timely treatment and at the same time will contribute to saving expenses in imports.

  17. Latex rubber condoms: predicting and extending shelf life.

    PubMed

    Free, M J; Srisamang, V; Vail, J; Mercer, D; Kotz, R; Marlowe, D E

    1996-04-01

    Condoms from five manufacturers were subjected to controlled exposures of heat, humidity, and air and to different natural environments in five countries. Under aerobic conditions (condoms in permeable packages or unpackaged), stress properties declined. The relationship between rate of decline as a function of temperature was quadratic. Under oxygen-restricted conditions (foil-wrapped packages) at average storage temperatures of 30 degrees C and lower, strain properties declined with little or no significant change in stress properties. The effect is to cause condoms to become stiffer; high-breakage rates in use have been correlated with product stiffening. A new rationale for accelerated-aging tests to predict condom shelf stability is suggested, including a test to control the trend of condoms to stiffen. Silicone lubricant, impermeable packaging, and inclusion of antioxidants in the condom formulation can prevent or minimize aerobic breakdown of latex condoms. Specifying low-modulus condoms can prevent excessive stiffening.

  18. Latex-like water-borne polyaniline for coating applications

    SciTech Connect

    Liu, H.; Clark, R.; Yang, S.C.

    1998-07-01

    The authors report the synthesis of a polymeric complex of polyaniline that is dispersed in water as a stable suspension. The polymer, PAN:PVME-MLA, is a molecular complex of polyaniline and poly(vinylmethylether-co-maleic acid). The synthetic process leads to a stable latex-like suspension in water. The water-borne conducting polymer, once dried as a thin film on a substrate, is not dissolvable by water or other solvents. An example of piece-dyeing process is presented to show its potential for electrostatic dissipation of textile products. Another example illustrates that the material may be used as electroactive thin-films for electrochromic windows and for rechargeable battery applications.

  19. Macrocyclic Diterpenoids from the Latex of Euphorbia helioscopia.

    PubMed

    Hua, Juan; Liu, Yan-Chun; Jing, Shu-Xi; Luo, Shi-Hong; Li, Sheng-Hong

    2015-12-01

    One new jatrophane diterpenoid, 7α,9β,15β-triacetoxy-3β-benzoyloxy-14β-hydroxyjatropha-5E,11E-diene (3), together with four known macrocyclic diterpenoids, euphoheliosnoid A (1), epieuphoscopin B (2), euphohelioscopin A (4) and euphoscopin C (5), were isolated from the stem latex of Euphorbia helioscopia. Their structures were established by spectroscopic analyses. In the anti-inflammatory assay, euphohelioscopin A (4) exhibited moderate inhibitory activity on the release of cytokine TNF-α (IC50 = 23.7 ± 1.7 μM), IL-6 (IC50 = 46.1 ± 1.1 μM) and chemokine MCP-1 (IC50 = 33.7 ± 3.8 μM) in lipopolysaccharide (LPS) induced RAW 264.7 macrophages without notable cytotoxicity (IC50 > 80 μM).

  20. Anti-diarrhoeal activity of the latex of Calotropis procera.

    PubMed

    Kumar, S; Dewan, S; Sangraula, H; Kumar, V L

    2001-06-01

    The dry latex (DL) of Calotropis procera (Asclepiadaceae), a potent anti-inflammatory agent has been evaluated for anti-diarrhoeal activity. Like atropine and phenylbutazone (PBZ), a single oral dose of DL (500 mg/kg) produced a significant decrease in frequency of defecation, severity of diarrhoea and afforded protection from diarrhoea in 80% rats treated with castor oil. To understand the mechanism of its anti-diarrhoeal activity, we further evaluated its effect on intestinal transit, castor oil induced intestinal fluid accumulation (enteropooling) and electrolyte concentration in the intestinal fluid. DL produced a decrease in intestinal transit (27-37%) as compared to both normal and castor oil treated animals. Unlike atropine, DL significantly inhibited castor oil induced enteropooling. However, it did not alter the electrolyte concentration in the intestinal fluid as compared to castor oil treated rats.

  1. Liquid marbles stabilized by charged polymer latexes: how does the drying of the latex particles affect the properties of liquid marbles?

    PubMed

    Sun, Guanqing; Sheng, Yifeng; Wu, Jie; Ma, Guanghui; Ngai, To

    2014-10-28

    The coating of solid particles on the surface of liquid in air makes liquid marbles a promising approach in the transportation of a small amount of liquid. The stabilization of liquid marbles by polymeric latex particles imparts extra triggers such as pH and temperature, leading to the remote manipulation of droplets for many potential applications. Because the functionalized polymeric latexes can exist either as colloidally stable latex or as flocculated latex in a dispersion, the drying of latex dispersions under different conditions may play a significant role in the stabilization of subsequent liquid marbles. This article presents the investigation of liquid marbles stabilized by poly(styrene-co-methacrylic acid) (PS-co-MAA) particles drying under varied conditions. Protonation of the particles before freeze drying makes the particles excellent liquid marble stabilizers, but it is hard to stabilize liquid marbles for particles dried in their deprotonated states. The static properties of liquid marbles with increasing concentrations of protonating reagent revealed that the liquid marbles are gradually undermined by protonating the stabilizers. Furthermore, the liquid marbles stabilized by different particles showed distinct behaviors in separation and merging manipulated by tweezers. This study shows that the initial state of the particles should be carefully taken into account in formulating liquid marbles.

  2. High speed cinematography of the initial break-point of latex condoms during the air burst test.

    PubMed

    Stube, R; Voeller, B; Davidhazy, A

    1990-06-01

    High speed cinematography of latex condoms inflated to burst under standard (ISO) conditions reveals that rupture of the condom typically is initiated at a small focal point on the shank of the condom and then rapidly propagates throughout the condom's surface, often ending with partial or full severance of the condom at its point of attachment to the air burst instrument. This sequence of events is the reverse of that sometimes hypothesized to occur, where initiation of burst was considered to begin at the attachment point and to constitute a testing method artifact. This hypothesis of breakage at the attachment point, if true, would diminish the value of the air burst test as a standard for assessing manufacturing quality control as well as for condom strength measurements and comparisons.

  3. Agglutination of human erythrocytes by the interaction of Zn(2+)ion with histidine-651 on the extracellular domain of band 3.

    PubMed

    Kiyotake, Kento; Ochiai, Hideharu; Yamaguchi, Takeo

    2016-05-01

    Clustering of band 3, chloride/bicarbonate exchanger, has been reported in Zn(2+)-treated human erythrocytes. However, the agglutination of human erythrocytes is also induced by the interaction of Zn(2+)ion with histidine on band 3. Identification of histidine that interacts with Zn(2+)ion remains to be determined. The Zn(2+)-induced agglutination of human erythrocytes was unaffected by chymotrypsin cleavage of the small loop region containing His-547 in the extracellular domain of band 3. On the other hand, papain digestion of the large loop region containing His-651 in band 3 inhibited such Zn(2+)-induced agglutination. Moreover, Zn(2+)-induced erythrocyte agglutination was inhibited by the peptide (ARGWVIHPLG) containing His-651, but not by the peptide such as ARGWVIRPLG, which His-651 was substituted by arginine. Among 10 kinds of animal erythrocytes tested, interestingly, no agglutination by Zn(2+)ions was observed in cow cells only that the forth amino acid in the upstream from His-669 on the large loop of cow band 3 is aspartate (Asp-665) instead of glycine. As expected, the agglutination of human erythrocytes by Zn(2+) ions was inhibited in the presence of aspartate. These data indicate that the interaction of Zn(2+) ion with His-651 residue of band 3 plays an important role in the Zn(2+)-induced agglutination of human erythrocytes.

  4. A review of natural-rubber latex allergy in health care workers.

    PubMed

    Ranta, Peter M; Ownby, Dennis R

    2004-01-15

    This brief review of natural-rubber latex (NRL) allergy in health care workers (HCWs) includes the definition of NRL allergy and data on its epidemiology, pathogenesis, diagnostic algorithm, management, long-term outcomes, economic impact, cost-effectiveness of changing facilities to a latex-free environment, and prevention. The data presented suggest that an individual with type I or type IV hypersensitivity to NRL should be able to continue to work in the workplace with careful evaluation and reasonable accommodations. Reducing exposure to latex is a safe and more economical alternative to complete removal of the individual from the place of employment. The use of low-allergen, nonpowdered NRL gloves substantially reduces airborne exposure to latex in most health care settings.

  5. Light-scattering study of the effect of salt and polyelectrolyte on magnetic latex particles

    SciTech Connect

    Sohn, D.; Russo, P.S.

    1993-12-31

    Dynamic and static light scattering methods have been used to study the interaction between magnetic latex and polyelectrolytes (polystyrene sulfonate sodium salt, NaPSS) in solution. The light scattering signal from magnetic latex particles was far stronger than that of the polyelectrolyte, especially during depolarized measurements where the polyelectrolyte was essentially invisible. Rotational and translational diffusion of the magnetic latex is investigated as a function of the NaPSS concentration and added salt (NaCl). The diffusion coefficient of magnetic latex decreases abruptly with increasing salt concentration when NaPSS is absent, but it recovers upon addition of NaPSS to the system. Static light scattering results also give evidence of particle aggregation at high salt.

  6. Evaluation of apparent viscosity of Para rubber latex by diffuse reflection near-infrared spectroscopy.

    PubMed

    Sirisomboon, Panmanas; Chowbankrang, Rawiphan; Williams, Phil

    2012-05-01

    Near-infrared spectroscopy in diffuse reflection mode was used to evaluate the apparent viscosity of Para rubber field latex and concentrated latex over the wavelength range of 1100 to 2500 nm, using partial least square regression (PLSR). The model with ten principal components (PCs) developed using the raw spectra accurately predicted the apparent viscosity with correlation coefficient (r), standard error of prediction (SEP), and bias of 0.974, 8.6 cP, and -0.4 cP, respectively. The ratio of the SEP to the standard deviation (RPD) and the ratio of the SEP to the range (RER) for the prediction were 4.4 and 16.7, respectively. Therefore, the model can be used for measurement of the apparent viscosity of field latex and concentrated latex in quality assurance and process control in the factory.

  7. Determination of the coalescence temperature of latexes by environmental scanning electron microscopy.

    PubMed

    Gonzalez, Edurne; Tollan, Christopher; Chuvilin, Andrey; Barandiaran, Maria J; Paulis, Maria

    2012-08-01

    A new methodology for quantitative characterization of the coalescence process of waterborne polymer dispersion (latex) particles by environmental scanning electron microscopy (ESEM) is proposed. The experimental setup has been developed to provide reproducible latex monolayer depositions, optimized contrast of the latex particles, and a reliable readout of the sample temperature. Quantification of the coalescence process under dry conditions has been performed by image processing based on evaluation of the image autocorrelation function. As a proof of concept the coalescence of two latexes with known and differing glass transition temperatures has been measured. It has been shown that a reproducibility of better than 1.5 °C can be obtained for the measurement of the coalescence temperature.

  8. Reproductive activity alterations on the Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex.

    PubMed

    Mello-Silva, Clélia Christina; Vilar, Mônica Magno; Bezerra, José Clecildo Barreto; Vasconcellos, Maurício Carvalho de; Pinheiro, Jairo; Rodrigues, Maria de Lurdes de A

    2007-09-01

    The reproductive activity of Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex was evaluated. Parameters related to fecundity and fertility were observed. The snails were exposed to the LD50 (1 mg/l) of crude latex. At the first week post exposure (p.e.), the egg laying was reduced. After the fourth week p.e., an increase of the number of eggs/snail occurred. The results showed a marked reduction in the hatching of the snails, revealing an interference of latex exposure with the reproductive process of B. glabrata of E. splendens var. hislopii. The LD50 of the latex may be used as an alternative method to control the size of the populations of B. glabrata in field.

  9. The characterization of latex particles prepared by pulsed electron beam induced emulsion polymerization

    NASA Astrophysics Data System (ADS)

    Xu, Yongfei; Wang, Mozhen; Ge, Xuewu

    2012-10-01

    The emulsion polymerization of styrene (St) and methyl methacrylate (MMA) induced by 10 MeV pulsed electron beams (PEB) was investigated. The monomer conversion of MMA and St was found to be very low so that the final prepared poly(methyl methacrylate) (P(MMA)) and polystyrene (PS) latex particles exhibit porous structures, as verified by TEM and SEM observations. The results of dynamic light scattering (DLS) and gel permeation chromatography (GPC) showed that both the particle size and the molecular weight of PS and PMMA latexes decrease with the increase of the absorbed dose. However, the molecular weights and the particle sizes of the PS and PMMA latexes change differently with the irradiation time. This work indicated that emulsion polymerization induced by high energy electron beam has an advantage over that induced by γ-ray or chemical initiators in the preparation of latex with a low molecular weight and porous structure.

  10. Extraction and characterization of a natural rubber from Euphorbia characias latex.

    PubMed

    Spanò, Delia; Pintus, Francesca; Mascia, Claudia; Scorciapino, Mariano Andrea; Casu, Mariano; Floris, Giovanni; Medda, Rosaria

    2012-08-01

    A natural rubber was identified and characterized for the first time in the latex of the perennial Mediterranean shrub Euphorbia characias. Four different methods, i.e., acetone, acetic acid, trichloroacetic acid, and Triton® X-100, followed by successive treatments with cyclohexane/ethanol, were employed to extract the natural rubber. The rubber content was shown to be 14% (w/v) of the E. characias latex, a low content compared with that of Hevea brasiliensis (30-35%) but a similar content to other rubber producing plants. E. characias rubber showed a molecular weight of 93,000 with a M(w) /M(n) of 2.9. (1) H NMR, (13) C NMR, and FTIR analysis revealed the characteristic of the cis-1,4-polyisoprene typical of natural rubber. These results provided novel insight into latex components and will ultimately benefit the broader understanding of E. characias latex composition.

  11. Reduction of cytotoxicity of natural rubber latex film by coating with PMMA-chitosan nanoparticles.

    PubMed

    Kanjanathaworn, Nuttakun; Polpanich, Duangporn; Jangpatarapongsa, Kulachart; Tangboriboonrat, Pramuan

    2013-08-14

    Poly(methyl methacrylate) (PMMA) latex stabilized by chitosan (CS) oligomer was synthesized via the miniemulsion polymerization. By using 1% CS solution (in 0.1M acetic acid), the spherical PMMA-CS particles with an average size of 380 nm were obtained. The positive zeta potentials at pH 2-7 confirmed the presence of CS as the outermost layer of the latex particles. Therefore, these particles directly interacted with the indigenous non-rubbers at the surface of sulphur prevulcanized natural rubber (SPNR) film. The deposition of PMMA-CS particles caused an increase in surface roughness of the coated SPNR film as a function of latex concentration and immersion time. The simple coating of the rubber substrate with PMMA-CS particles effectively reduced the in vitro cytotoxicity on L-929 cells. This study would be, therefore, helpful for development of latex gloves designed for hypersensitive users.

  12. Engineering Multifunctional Living Paints: Thin, Convectively-Assembled Biocomposite Coatings of Live Cells and Colloidal Latex Particles Deposited by Continuous Convective-Sedimentation Assembly

    NASA Astrophysics Data System (ADS)

    Jenkins, Jessica Shawn

    Advanced composite materials could be revolutionized by the development of methods to incorporate living cells into functional materials and devices. This could be accomplished by continuously and rapidly depositing thin ordered arrays of adhesive colloidal latex particles and live cells that maintain stability and preserve microbial reactivity. Convective assembly is one method of rapidly assembling colloidal particles into thin (<10 microm thick), ordered films with engineered compositions, thicknesses, and particle packing that offer several advantages over thicker randomly ordered composites, including enhanced cell stability and increased reactivity through minimized diffusion resistance to nutrients and reduced light scattering. This method can be used to precisely deposit live bacteria, cyanobacteria, yeast, and algae into biocomposite coatings, forming reactive biosensors, photoabsorbers, or advanced biocatalysts. This dissertation developed new continuous deposition and coating characterization methods for fabricating and characterizing <10 microm thick colloid coatings---monodispersed latex particle or cell suspensions, bimodal blends of latex particles or live cells and microspheres, and trimodal formulations of biomodal latex and live cells on substrates such as aluminum foil, glass, porous Kraft paper, polyester, and polypropylene. Continuous convective-sedimentation assembly (CSA) is introduced to enable fabrication of larger surface area and long coatings by constantly feeding coating suspension to the meniscus, thus expanding the utility of convective assembly to deposit monolayer or very thin films or multi-layer coatings composed of thin layers on a large scale. Results show thin, tunable coatings can be fabricated from diverse coating suspensions and critical coating parameters that control thickness and structure. Particle size ratio and charge influence deposition, convective mixing or demixing and relative particle locations. Substrate

  13. [Powder-induced anaphylactic shock following use of powdered latex gloves during gynecological open laparotomy].

    PubMed

    Mizuno, Ju; In-nami, Hiroshi; Saegusa, Hiroaki; Kibayashi, Junichiro; Jimbo, Masanori; Kida, Kotaro; Ichiishi, Noriko

    2006-06-01

    A 42-year-old woman with hysteromyoma underwent total abdominal hysterectomy under general and epidural anesthesia. Three years before, she had undergone resection of lipoma on her left shoulder under local anesthesia uneventfully. She had no previous history of hypersensitivity. General anesthesia was induced by intravenous injection of fentanyl, propofol, and vecuronium followed by inhalation of nitrous oxide, oxygen, and sevoflurane. Lidocaine and fentanyl were injected through a lumbar epidural catheter. After the start of open laparotomy, there was a sudden onset of hypotension. Administrations of ephedrine and phenylephrine, and volume loading were ineffective. Moreover, she showed profound hypotension, tachycardia, oxygen desaturation, decreased endtidal carbon dioxide and increased airway pressure. She broke out in a sweat with flushing on her chest and upper extremities. Therefore, we interrupted the surgery, checked her arterial blood gas analysis, performed echocardiography, and inserted a pulmonary artery catheter. We made a diagnosis of anaphylactic shock and administered methylprednisolone, albumin, epinephrine, norepinephrine, and dopamine to treat the circulatory collapse. The gynecologists changed their surgical gloves from a powdered-latex type to a powder-free latex type, and the surgery was resumed. She responded well to appropriate emergent therapy and all vasopressor drugs were gradually decreased and eventually stopped. After the end of the surgery, she recovered completely from the signs and symptoms of shock. Later, we found a high level of plasma latex protein-specific IgE antibody and confirmed the events as anaphylactic shock due to latex. We assumed that the anaphylactic shock was powder-induced latex allergy following use of powdered latex gloves in this case. Latex allergy should be suspected if an anaphylactic reaction or shock accompanied by circulatory collapse, respiratory failure, and skin symptoms of unknown origin occurs during

  14. Radiation grafting of methyl methacrylate monomer on natural rubber latex. [Gamma radiation

    SciTech Connect

    Sundardi, F.; Kadariah, S.

    1984-05-01

    A method of radiation grafting of methyl methacrylate (MMA) monomer on natural rubber (NR) latex has been studied. The irradiation dose in radiation emulsion polymerization of MMA monomer was lower compared to the irradiation dose for grafting of MMA monomer on NR latex, in order to obtain the same degree of conversion. This is due to the size of the rubber particles which are quite large and, hence, not sufficient to ensure an ideal emulsion polymerization. The irradiation dose for radiation grafting of MMA monomer on latex was around 300 krad to obtain a 75% degree of conversion. However, this irradiation dose was lower compared to the irradiation dose for bulk polymerization of MMA momomer, in order to obtain the same degree of conversion. This is due to the gel effect in the viscous media. Radiation grafting of MMA monomer on NR latex does not influence the pH of the latex, but influences the viscosity significantly. The viscosity of the NR latex increased with an increase in irradiation dose, due to the increase of the total solid content in the latex. The MMA monomer converted to P-MMA in NR latex was largely grafted on the NR, or at least insoluble in a solvent for P-MMA, such as acetone or toluene. The hardness of the pure gum vulcanizate increased with an increase in the degree of grafting or P-MMA content, but the other physical properties, such as tensile strength, modulus, elongation at break, and thermal stability, were not greatly influenced by the degree of grafting. 9 references, 3 figures, 5 tables.

  15. Design of polystyrene latex particles covered with polyoxometalate clusters via multiple covalent bonding

    DOE PAGES

    Chen, Xinyue; Li, Hui; Yin, Panchao; ...

    2015-01-01

    In this study, polyoxometalates (POMs) covalently functionalized with methyl methacrylate groups were applied as surfactants in the emulsion polymerization reaction of styrene. Due to the copolymerization of the methyl methacrylate groups and the styrene monomers, the polyoxometalate clusters are covalently grafted onto the surface of polystyrene latex nanoparticles. Finally, such latex particles are fully covered with catalytic POM clusters and might serve as quasi-homogeneous catalysts.

  16. Permeability and reactivity of Thermotoga maritima in latex bimodal blend coatings at 80 degrees C: a model high temperature biocatalytic coating.

    PubMed

    Lyngberg, Olav K; Solheid, Chris; Charaniya, Salim; Ma, Yue; Thiagarajan, Venkata; Scriven, L E; Flickinger, Michael C

    2005-06-01

    Thermostable polymers cast as thin, porous coatings or membranes may be useful for concentrating and stabilizing hyperthermophilic microorganisms as biocatalysts. Hydrogel matrices can be unstable above 65 degrees C. Therefore a 55-microm thick, two layer (cell coat + polymer top coat) bimodal, adhesive latex coating of partially coalesced polystyrene particles was investigated at 80 degrees C using Thermotoga maritima as a model hyperthermophile. Coating permeability (pore structure) was critical for maintaining T. maritima viability. The permeability of bimodal coatings generated from 0.8 v/v of a suspension of non-film-forming 800 nm polystyrene particles with high glass transition temperature (T(g) = 94 degrees C, 26.9% total solids) blended with 0.2 v/v of a suspension of film-forming 158 nm polyacrylate/styrene particles (T(g) approximately -5 degrees C, 40.9% total solids) with 0.3 g sucrose/g latex was measured in a KNO3 diffusion cell. Diffusivity ratio remained above 0.04 (D(eff)/D) when incubated at 80 degrees C in artificial seawater (ASW) for 5 days. KNO3 permeability was corroborated by cryogenic-SEM images of the pore structure. In contrast, the permeability of a mono-dispersed acrylate/vinyl acetate latex Rovace SF091 (T(g) approximately 10 degrees C) rapidly decreased and became impermeable after 2 days incubation in ASW at 80 degrees C. Thermotoga maritima were entrapped in these coatings at a cell density of 49 g cell wet weight/liter of coating volume, 25-fold higher than the density in liquid culture. Viable T. maritima were released from single-layer coatings at 80 degrees C but accurate measurement of the percentage of viable entrapped cells by plate counting was not successful. Metabolic activity could be measured in bilayer coatings by utilization of glucose and maltose, which was identical for latex-entrapped and suspended cells. Starch was hydrolyzed for 200 h by latex-entrapped cells due to the slow diffusion of starch through the

  17. A comparison of titers of anti-Brucella antibodies of naturally infected and healthy vaccinated cattle by standard tube agglutination test, microtiter plate agglutination test, indirect hemagglutination assay, and indirect enzyme-linked immunosorbent assay

    PubMed Central

    Mohan, Anju; Saxena, Hari Mohan; Malhotra, Puneet

    2016-01-01

    Aim: We determined the antibody response in cattle naturally infected with brucellosis and normal healthy adult cattle vaccinated during calf hood with strain 19. Materials and Methods: The antibody titers were measured by standard tube agglutination test (STAT), microtiter plate agglutination test (MAT), indirect hemagglutination assay (IHA), and indirect enzyme-linked immunosorbent assay (iELISA) as per standard protocols. Results: The mean STAT titers were 1.963±0.345 in infected cattle and 1.200±0.155 in healthy vaccinated cattle. The difference was extremely significant (p<0.0001). The mean MAT titers were 2.244±0.727 in infected cattle and 1.200±0.155 in healthy vaccinated cattle. The difference was very significant (p<0.005). The mean IHA titers in infected cattle were 2.284±0.574, and those in healthy vaccinated cattle were 1.200±0.155. The difference was extremely significant (p=0.0002). However, the difference in mean iELISA titers of infected cattle (1.3678±0.014) and healthy vaccinated cattle (1.367±0.014) was non-significant. The infected animals showed very high titers of agglutinating antibodies compared to the vaccinated animals. However, it cannot be ascertained whether these antibodies are due to vaccine or response to infection. Since the infected animals had been vaccinated earlier, the current infection may suggest that vaccination was unable to induce protective levels of antibody. The heightened antibody response after infection may also indicate a secondary immune response to the antigens common to the vaccine strain and wild Brucella organisms. Conclusion: The brucellosis infected animals showed very high titers of agglutinating antibodies compared to the vaccinated animals. PMID:27536032

  18. Capacitance Regression Modelling Analysis on Latex from Selected Rubber Tree Clones

    NASA Astrophysics Data System (ADS)

    Rosli, A. D.; Hashim, H.; Khairuzzaman, N. A.; Mohd Sampian, A. F.; Baharudin, R.; Abdullah, N. E.; Sulaiman, M. S.; Kamaru'zzaman, M.

    2015-11-01

    This paper investigates the capacitance regression modelling performance of latex for various rubber tree clones, namely clone 2002, 2008, 2014 and 3001. Conventionally, the rubber tree clones identification are based on observation towards tree features such as shape of leaf, trunk, branching habit and pattern of seeds texture. The former method requires expert persons and very time-consuming. Currently, there is no sensing device based on electrical properties that can be employed to measure different clones from latex samples. Hence, with a hypothesis that the dielectric constant of each clone varies, this paper discusses the development of a capacitance sensor via Capacitance Comparison Bridge (known as capacitance sensor) to measure an output voltage of different latex samples. The proposed sensor is initially tested with 30ml of latex sample prior to gradually addition of dilution water. The output voltage and capacitance obtained from the test are recorded and analyzed using Simple Linear Regression (SLR) model. This work outcome infers that latex clone of 2002 has produced the highest and reliable linear regression line with determination coefficient of 91.24%. In addition, the study also found that the capacitive elements in latex samples deteriorate if it is diluted with higher volume of water.

  19. Oral dosing with papaya latex is an effective anthelmintic treatment for sheep infected with Haemonchus contortus

    PubMed Central

    2011-01-01

    Background The cysteine proteinases in papaya latex have been shown to have potent anthelmintic properties in monogastric hosts such as rodents, pigs and humans, but this has not been demonstrated in ruminants. Methods In two experiments, sheep were infected concurrently with 5,000 infective larvae of Haemonchus contortus and 10,000 infective larvae of Trichostrongylus colubriformis and were then treated with the supernatant from a suspension of papaya latex from day 28 to day 32 post-infection. Faecal egg counts were monitored from a week before treatment until the end of the experiment and worm burdens were assessed on day 35 post-infection. Results We found that the soluble fraction of papaya latex had a potent in vivo effect on the abomasal nematode H. contortus, but not on the small intestinal nematode T. colubriformis. This effect was dose-dependent and at tolerated levels of gavage with papaya latex (117 μmol of active papaya latex supernatant for 4 days), the H. contortus worm burdens were reduced by 98%. Repeated treatment, daily for 4 days, was more effective than a single dose, but efficacy was not enhanced by concurrent treatment with the antacid cimetidine. Conclusions Our results provide support for the idea that cysteine proteinases derived from papaya latex may be developed into novel anthelmintics for the treatment of lumenal stages of gastro-intestinal nematode infections in sheep, particularly those parasitizing the abomasum. PMID:21406090

  20. Papain protects papaya trees from herbivorous insects: role of cysteine proteases in latex.

    PubMed

    Konno, Kotaro; Hirayama, Chikara; Nakamura, Masatoshi; Tateishi, Ken; Tamura, Yasumori; Hattori, Makoto; Kohno, Katsuyuki

    2004-02-01

    Many plants contain latex that exudes when leaves are damaged, and a number of proteins and enzymes have been found in it. The roles of those latex proteins and enzymes are as yet poorly understood. We found that papain, a cysteine protease in latex of the Papaya tree (Carica papaya, Caricaceae), is a crucial factor in the defense of the papaya tree against lepidopteran larvae such as oligophagous Samia ricini (Saturniidae) and two notorious polyphagous pests, Mamestra brassicae (Noctuidae) and Spodoptera litura (Noctuidae). Leaves of a number of laticiferous plants, including papaya and a wild fig, Ficus virgata (Moraceae), showed strong toxicity and growth inhibition against lepidopteran larvae, though no apparent toxic factors from these species have been reported. When the latex was washed off, the leaves of these lactiferous plants lost toxicity. Latexes of both papaya and the wild fig were rich in cysteine-protease activity. E-64, a cysteine protease-specific inhibitor, completely deprived the leaves of toxicity when painted on the surface of papaya and fig leaves. Cysteine proteases, such as papain, ficin, and bromelain, all showed toxicity. The results suggest that plant latex and the proteins in it, cysteine proteases in particular, provide plants with a general defense mechanism against herbivorous insects.

  1. Ficus carica latex-mediated synthesis of silver nanoparticles and its application as a chemophotoprotective agent.

    PubMed

    Borase, Hemant P; Patil, Chandrashekhar D; Suryawanshi, Rahul K; Patil, Satish V

    2013-10-01

    The present work provides scientific support on the use of latex of Ficus carica to synthesize stable silver nanoparticles (AgNPs). AgNPs synthesized immediately after the addition of latex to silver nitrate solution at room temperature. Synthesized nanoparticles were of spherical shape with average size of 163.7 nm. Fourier transform infrared spectroscopy analysis revealed capping of proteins and phenolic compound on AgNPs, while X-ray diffraction analysis confirmed the fcc nature of AgNPs. Particles formed were stable for a long time (6 months). It was found that incorporation of AgNPs with 2 and 4% concentration exhibits synergistic increase in sun protection factor of commercial sunscreen and natural extracts ranging from 01 to 12,175% than control. Further characterization of latex and AgNPs revealed total phenolic content of 98.75 and 94.88 μg/ml. The ferric ion reduction potentials of latex and AgNPs were 79.69 and 18.79%. Reduction potential of ascorbic acid was synergistically increased after cumulative preparation of ascorbic acid with latex and AgNPs and found to be 106.76 and 101.50% for ascorbic acid + latex and ascorbic acid + AgNPs, respectively.

  2. Enhanced protein adsorption and patterning on nanostructured latex-coated paper.

    PubMed

    Juvonen, Helka; Määttänen, Anni; Ihalainen, Petri; Viitala, Tapani; Sarfraz, Jawad; Peltonen, Jouko

    2014-06-01

    Specific interactions of extracellular matrix proteins with cells and their adhesion to the substrate are important for cell growth. A nanopatterned latex-coated paper substrate previously shown to be an excellent substrate for cell adhesion and 2D growth was studied for directed immobilization of proteins. The nanostructured latex surface was formed by short-wavelength IR irradiation of a two-component latex coating consisting of a hydrophilic film-forming styrene butadiene acrylonitrile copolymer and hydrophobic polystyrene particles. The hydrophobic regions of the IR-treated latex coating showed strong adhesion of bovine serum albumin (cell repelling protein), fibronectin (cell adhesive protein) and streptavidin. Opposite to the IR-treated surface, fibronectin and streptavidin had a poor affinity toward the untreated pristine latex coating. Detailed characterization of the physicochemical surface properties of the latex-coated substrates revealed that the observed differences in protein affinity were mainly due to the presence or absence of the protein repelling polar and charged surface groups. The protein adsorption was assisted by hydrophobic (dehydration) interactions.

  3. Physical Methods for the Preparation of Hybrid Nanocomposite Polymer Latex Particles

    NASA Astrophysics Data System (ADS)

    Teixeira, Roberto F. A.; Bon, Stefan A. F.

    In this chapter, we will highlight conceptual physical approaches towards the fabrication of nanocomposite polymer latexes in which each individual latex particle contains one or more "hard" nanoparticles, such as clays, silicates, titanates, or other metal(oxides). By "physical approaches" we mean that the "hard" nanoparticles are added as pre-existing entities, and are not synthesized in situ as part of the nanocomposite polymer latex fabrication process. We will narrow our discussion to focus on physical methods that rely on the assembly of nanoparticles onto the latex particles after the latex particles have been formed, or its reciprocal analogue, the adhesion of polymer onto an inorganic nanoparticle. First, will discuss the phenomenon of heterocoagulation and its various driving forces, such as electrostatic interactions, the hydrophobic effect, and secondary molecular interactions. We will then address methods that involve assembly of nanoparticles onto or around the more liquid precursors (i.e., swollen/growing latex particles or monomer droplets). We will focus on the phenomenon of Pickering stabilization. We will then discuss features of particle interaction with soft interfaces, and see how the adhesion of particles onto emulsion droplets can be applied in suspension, miniemulsion, and emulsion polymerization. Finally, we will very briefly mention some interesting methods that make use of interface-driven templating for making well-defined assembled clusters and supracolloidal structures.

  4. Latex Rubber Gloves as a Sampling Dosimeter Using a Novel Surrogate Sampling Device.

    PubMed

    Sankaran, Gayatri; Lopez, Terry; Ries, Steve; Ross, John; Vega, Helen; Eastmond, David A; Krieger, Robert I

    2015-01-01

    Pesticide exposure during harvesting of crops occurs primarily to the workers' hands. When harvesters wear latex rubber gloves for personal safety and hygiene harvesting reasons, gloves accumulate pesticide residues. Hence, characterization of the gloves' properties may be useful for pesticide exposure assessments. Controlled field studies were conducted using latex rubber gloves to define the factors that influence the transfer of pesticides to the glove and that would affect their use as a residue monitoring device. A novel sampling device called the Brinkman Contact Transfer Unit (BCTU) was constructed to study the glove characteristics and residue transfer and accumulation under controlled conditions on turf. The effectiveness of latex rubber gloves as sampling dosimeters was evaluated by measuring the transferable pesticide residues as a function of time. The validation of latex rubber gloves as a residue sampling dosimeter was performed by comparing pesticide transfer and dissipation from the gloves, with the turf transferable residues sampled using the validated California (CA) Roller, a standard measure of residue transfer. The observed correlation (Pearson's correlation coefficient R(2)) between the two methods was .84 for malathion and .96 for fenpropathrin, indicating that the BCTU is a useful, reliable surrogate tool for studying available residue transfer to latex rubber gloves under experimental conditions. Perhaps more importantly, these data demonstrate that latex gloves worn by workers may be useful quantifiable matrices for measuring pesticide exposure.

  5. Sensitization from chestnuts and bananas in patients with urticaria and anaphylaxis from contact with latex.

    PubMed

    Fernández de Corres, L; Moneo, I; Muñoz, D; Bernaola, G; Fernández, E; Audicana, M; Urrutia, I

    1993-01-01

    We present eight patients allergic to latex and fruit (chestnut and banana), seven of whom are women, and aged 17 to 42 years (mean 25 years). Four had family and five personal atopic histories. The total IgE varied from 41 to 520 Ku/L (mean 263). The symptoms followed ingestion of fruit (anaphylaxis) in four patients and contact with rubber (contact urticaria and anaphylaxis) in the other four. Skin prick test (SPT) with latex and radioallergosorbent test to latex were positive in all the patients. Histamine release (HR) to latex was carried out on six patients and was positive in three. In the six patients with symptoms after having eaten chestnuts the SPT was positive and specific IgE was detected in five of them. Histamine release to chestnuts was positive in three of the six patients tested and one of them (-SPT and + IgE) tolerated the fruit. Two out of five patients with symptomatic banana allergy had negative SPT with banana while the test was positive in one patient who tolerated this fruit, this being the only case with specific IgE to banana. Histamine release with banana was only positive in one case. The important correlation between SPT, RAST, and HR results to latex and chestnut together with the total inhibition of the chestnut RAST with a serum pool by preincubation with latex suggests cross-reactivity among these allergens.

  6. Cytotoxic, cell agglutinating, and syncytium forming effect of purified lectins from Ricinus communis on cultured cells.

    PubMed

    Koga, M; Ohtsu, M; Funatsu, G

    1979-10-01

    The toxicity of lectins from castor bean (Ricinus communis L.), ricin-D, ricin-E, and castor bean hemagglutinin, was investigated on five cultured cell lines. The differential effect of their constituent polypeptide chains was also investigated using these cell lines. Ricin-D, ricin-E, and castor bean hemagglutinin (CBH) possessed cytoagglutinating activity and cytotoxic activity to all five cell lines. These lectins showed the strongest toxicity to L5178Y cells, which are leukemic cells. The toxic activity of ricin-D was stronger than that of CBH in all cell lines. The constituent polypebtide chains of ricin-D and CBH were separated by DEAE-cellulose chromatography and designated as isoleucine chain and alanine chain denoted by their N-terminal amino acids. Only alanine chain of ricin-D was toxic to cells grown in vitro, whereas isoleucine chain of ricin-D and alanine chain of CBH were not toxic to the cells. Moreover, it was found that both lectins caused syncytium formation in NIH3T3 cells infected with Moloney leukemia virus and this cell fusion activity was shown to be exclusively associated with the alanine chain. Cytotoxic, cell agglutinating, and syncytium forming effect of the lectins is due to binding of the alanine chain of ricin-D to galactose-like residues of the membrane constituents of these cells.

  7. A systematic review on the microscopic agglutination test seroepidemiology of bovine leptospirosis in Latin America.

    PubMed

    Pinto, Priscila da Silva; Libonati, Hugo; Penna, Bruno; Lilenbaum, Walter

    2016-02-01

    The diagnosis of leptospirosis commonly relies on serology, which has three issues that are referred: the sampling, the antigen panel, and the cutoff point. We propose a systematic review of the bovine leptospirosis in Latin America, in order to provide a better understanding of the evolution of the research and of the seroepidemiology of bovine leptospirosis in that region. Internet databases were consulted over the year of 2014. Inclusion criteria for analysis included serosurvey using microscopic agglutination test (MAT), a relevant number of animals, the presence in the antigen panel of at least one representant of serogroup Sejroe, and a cutoff point of ≥100. A total of 242 articles that referred to cattle, leptospir*, and one region of Latin America was found. Only 105 articles regarding to serosurveys using MAT were found in several countries, and 61 (58.1 %) met all the inclusion criteria. In conclusion, this systematic review demonstrated a high prevalence of the infection (75.0 % at herd level and 44.2 % at animal level), with predominance of strains of serogroup Sejroe (80.3 %). It was evident that there is the necessity of more studies in several countries, as well as the need for greater standardization in studies, especially with regard to the adopted cutoff point at serological tests.

  8. Reading development in agglutinative languages: evidence from beginning, intermediate, and adult Basque readers.

    PubMed

    Acha, Joana; Laka, Itziar; Perea, Manuel

    2010-04-01

    Do typological properties of language, such as agglutination (i.e., the morphological process of adding affixes to the lexeme of a word), have an impact on the development of visual word recognition? To answer this question, we carried out an experiment in which beginning, intermediate, and adult Basque readers (n=32 each, average age=7, 11, and 22 years, respectively) needed to read correctly versus incorrectly inflected words embedded in sentences. Half of the targets contained high-frequency stems, and the other half contained low-frequency stems. To each stem, four inflections of different lengths were attached (-a, -ari, -aren, and -arentzat, i.e., inflectional sequences). To test whether the process of word recognition was modulated by the knowledge of word structure in the language, half of the participants' native language was Basque and the other half's native language was Spanish. Children showed robust effects of frequency and length of inflection that diminished with age. In addition, the effect of length of inflection was modulated by the frequency of the stem and by the native language. Taken together, these results suggest that word recognition develops from a decoding strategy to a direct lexical access strategy and that this process is modulated by children's knowledge of the inflectional structure of words from the beginning of their reading experience.

  9. Type 2B von Willebrand disease associated with the release of platelet agglutinates from megakaryocytes in the bone marrow.

    PubMed

    Slayton, William B; Patel, Milin; Sola-Visner, Martha; Harris, Neil; Rivers, Angela; Montgomery, Robert R; Friedman, Kenneth D

    2008-09-01

    We report a child with thrombocytopenia since birth, circulating platelet agglutinates, and a tendency to bleed. A bone marrow aspirate revealed large platelet clumps within the bone marrow and megakaryocyte nuclei surrounded by halos of clumped platelets. Laboratory evaluation revealed type 2B von Willebrand disease. Gene sequencing revealed a G to C mutation at base 3923 of the VWF gene. This mutation was previously described in a family with circulating platelet clumps and abnormal megakaryopoiesis with release of clumped platelets in culture. This same mutation was previously described in a family with circulating platelet aggregates and abnormalities of platelet release from megakaryocytes in vitro. Presence of megakaryocytes with halos of clumped platelets in our patient suggests that platelet agglutinate occurs in the bone marrow in some type 2B von Willebrand disease patients.

  10. An acousto-optical method for registration of erythrocytes' agglutination reaction—sera color influence on the resolving power

    NASA Astrophysics Data System (ADS)

    Doubrovski, V. A.; Medvedeva, M. F.; Torbin, S. O.

    2016-01-01

    The absorption spectra of agglutinating sera were used to determine blood groups. It was shown experimentally that the sera color significantly affects the resolving power of the acousto-optical method of blood typing. In order to increase the resolving power of the method and produce an invariance of the method for sera color, we suggested introducing a probing light beam individually for different sera. The proposed technique not only improves the resolving power of the method, but also reduces the risk of false interpretation of the experimental results and, hence, error in determining the blood group of the sample. The latter is especially important for the typing of blood samples with weak agglutination of erythrocytes. This study can be used in the development of an instrument for instrumental human blood group typing based on the acousto-optical method.

  11. Spectral dependence of resolving power of optical method of detection of ultrasonically enhanced agglutination of human blood erythrocytes

    NASA Astrophysics Data System (ADS)

    Doubrovski, V. A.; Dvoretski, K. N.; Dolmashkin, A. A.

    2010-08-01

    The spectral dependence of the resolving power of an acoustooptic method of monitoring agglutination of human blood erythrocytes is studied theoretically and experimentally. It is shown that, in principle, the resolving power of this method can be increased by several dozen times. The results of the work can be used to create instruments for determining the human blood type in the AB0 system and in the Rhesus system.

  12. A technique for detection of agglutinating activity of antilymphocytic serum using formalinized and trypan-blue-stained lymphocytes

    PubMed Central

    Janković, B. D.; Isaković, Katarina; Petrović, Spomenka

    1970-01-01

    This paper describes technical details of a micro-reaction for the in vitro detection of agglutinating potency of antilymphocytic serum produced in rabbits with chicken, rat and dog thymus cells. The titration of antilymphocytic serum includes the use of microtitre plastic plates and lymphocytes treated with formalin and stained with trypan blue stain. Formalinized and stained lymphocytes represent a stable antigen of long durability, and the application of those cells in leucoagglutination increases the accuracy and sensitivity of the reaction. PMID:5477930

  13. Serological evidence of Leishmania donovani infection in apparently healthy dogs using direct agglutination test (DAT) and rk39 dipstick tests in Kafta Humera, north-west Ethiopia.

    PubMed

    Kalayou, S; Tadelle, H; Bsrat, A; Abebe, N; Haileselassie, M; Schallig, H D F H

    2011-06-01

    Leishmania (Kinetoplastida: Trypanosomatidae) are protozoan parasites of significant medical and veterinary importance. Over the last decade, visceral leishmaniasis (VL) has emerged as a major opportunistic infection associated with HIV/AIDS in North Western Ethiopia. This paper reports on serological evidence of possible Leishmania donovani (L. donovani) infection in dogs using two serological tests: direct agglutination test (DAT) and Kalazar detect rapid test (KDRT). Two hundred and seventeen asymptomatic local breed dogs were examined for L. donovani antibodies. Performance of the DAT and KDRT was assessed in 162 matching samples of blood collected on filter paper and serum, respectively. Using DAT and KDRT testing in parallel, the overall seroprevalence of L. donovani infection was 27.7% and 14.8%, respectively. The degree of agreement was found to be fair (68.8%, k = 0.234). Univariable logistic regression analysis of some risk factors for L. donovani infection in dogs using DAT indicates that place of residence, sex, age, dog keeping purpose and dog housing condition were not significantly associated with seropositivity. The high proportion of positive dogs suggests the exposure of these animals to L. donovani infection and needs further investigation. Isolation and typing of the parasite aiming at confirming the role of these animals in maintenance and transmission of kala-azar is advocated.

  14. Comparison of optomagnetic and AC susceptibility readouts in a magnetic nanoparticle agglutination assay for detection of C-reactive protein.

    PubMed

    Fock, Jeppe; Parmvi, Mattias; Strömberg, Mattias; Svedlindh, Peter; Donolato, Marco; Hansen, Mikkel Fougt

    2017-02-15

    There is an increasing need to develop biosensor methods that are highly sensitive and that can be combined with low-cost consumables. The use of magnetic nanoparticles (MNPs) is attractive because their detection is compatible with low-cost disposables and because application of a magnetic field can be used to accelerate assay kinetics. We present the first study and comparison of the performance of magnetic susceptibility measurements and a newly proposed optomagnetic method. For the comparison we use the C-reactive protein (CRP) induced agglutination of identical samples of 100nm MNPs conjugated with CRP antibodies. Both methods detect agglutination as a shift to lower frequencies in measurements of the dynamics in response to an applied oscillating magnetic field. The magnetic susceptibility method probes the magnetic response whereas the optomagnetic technique probes the modulation of laser light transmitted through the sample. The two techniques provided highly correlated results upon agglutination when they measure the decrease of the signal from the individual MNPs (turn-off detection strategy), whereas the techniques provided different results, strongly depending on the read-out frequency, when detecting the signal due to MNP agglomerates (turn-on detection strategy). These observations are considered to be caused by differences in the volume-dependence of the magnetic and optical signals from agglomerates. The highest signal from agglomerates was found in the optomagnetic signal at low frequencies.

  15. Agglutinating Activity and Structural Characterization of Scalarin, the Major Egg Protein of the Snail Pomacea scalaris (d’Orbigny, 1832)

    PubMed Central

    Ituarte, Santiago; Dreon, Marcos Sebastián; Ceolin, Marcelo; Heras, Horacio

    2012-01-01

    Apple snail perivitellins are emerging as ecologically important reproductive proteins. To elucidate if the protective functions of the egg proteins of Pomacea canaliculata (Caenogastropoda, Ampullariidae), involved in embryo defenses, are present in other Pomacea species we studied scalarin (PsSC), the major perivitellin of Pomacea scalaris. Using small angle X-ray scattering, fluorescence and absorption spectroscopy and biochemical methods, we analyzed PsSC structural stability, agglutinating activity, sugar specificity and protease resistance. PsSC aggluttinated rabbit, and, to a lesser extent, human B and A erythrocytes independently of divalent metals Ca2+ and Mg2+ were strongly inhibited by galactosamine and glucosamine. The protein was structurally stable between pH 2.0 to 10.0, though agglutination occurred only between pH 4.0 to 8.0 (maximum activity at pH 7.0). The agglutinating activity was conserved up to 60°C and completely lost above 80°C, in agreement with the structural thermal stability of the protein (up to 60°C). PsSC was able to withstand in vitro gastrointestinal digestion, and showed no trypsin inhibition activity. The presence of lectin activity has been reported in eggs of other Pomacea snails, but here we link for the first time, this activity to an apple snail multifunctional perivitellin. This novel role for a snail egg storage protein is different from closely related P.canaliculata defensive proteins. PMID:23185551

  16. Agglutination of human O erythrocytes by influenza A(H1N1) viruses freshly isolated from patients.

    PubMed

    Murakami, T; Haruki, K; Seto, Y; Kimura, T; Minoshiro, S; Shibe, K

    1991-04-01

    The hemagglutinin titers of 10 influenza A (H1N1) viruses were examined using the erythrocytes of several species. Human O erythrocytes showed the highest agglutination titer to the viruses, whereas chicken erythrocytes showed a low titer. These findings were noted for at least 10 passages by serial dilutions of the viruses in Madin-Darby canine kidney (MDCK) cells. All influenza A(H1N1) viruses, plaque-cloned directly from throat-washing specimens of patients, also agglutinated human O but not chicken erythrocytes. The results of a hemadsorption test indicated that chicken erythrocytes possess less affinity to MDCK cells infected with the A/Osaka City/2/88(H1N1) stain than to those infected with the A/Yamagata/120/86(H1N1) strain which is used as an inactivated influenza vaccine in Japan. However, there were no significant differences between the A/Osaka City/2/88 and the A/Yamagata/120/86 strains in the hemagglutination inhibition test. Since human O erythrocytes have high agglutination activity to influenza A(H1N1) and also to A(H3N2) and B viruses in MDCK cells, these erythrocytes may be useful for the serological diagnosis of influenza.

  17. Application of a spectrally filtered probing light beam and RGB decomposition of microphotographs for flow registration of ultrasonically enhanced agglutination of erythrocytes

    NASA Astrophysics Data System (ADS)

    Doubrovski, V. A.; Ganilova, Yu. A.; Zabenkov, I. V.

    2013-08-01

    We propose a development of the flow microscopy method to increase the resolving power upon registration of erythrocyte agglutination. We experimentally show that the action of a ultrasonic standing wave on an agglutinating mixture blood-serum leads to the formation of so large erythrocytic immune complexes that it seems possible to propose a new two-wave optical method of registration of the process of erythrocyte agglutination using the RGB decomposition of microphotographs of the flow of the mixture under study. This approach increases the reliability of registration of erythrocyte agglutination and, consequently, increases the reliability of blood typing. Our results can be used in the development of instruments for automatic human blood typing.

  18. R and G color component competition of RGB image decomposition as a criterion to register RBC agglutinates for blood group typing.

    PubMed

    Doubrovski, Valeri A; Ganilova, Yuliya A; Zabenkov, Igor V

    2014-03-01

    A new approach of the criterion assignment for registration of erythrocyte agglutinates to instrumentally determine blood group type is suggested. The criterion is based on comparison of R and G components of RGB decomposition of microscopy digital image taken for the blood-serum mixture sample. For the chosen experimental conditions, the minimal size (area) of RBC agglutinate to be registered by the criterion suggested is estimated theoretically. The proposed method was tested experimentally on the example of monitoring agglutinates in flow. The encouraging experimental results were obtained for improvement of the resolving power of the method; the optimal experimental conditions were revealed for maximum resolution. Though the suggested method was realized for dynamic (flow) blood group determination, it could also be applied for diagnostics in a stationary environment. This approach increases the reliability of RBC agglutinates registration and, hence, blood group typing. The results may be used to develop the apparatus for automated determination of human blood group.

  19. [Evaluation of Prolex for the rapid identification of streptococci isolated in medical microbiology].

    PubMed

    Loubinoux, J; Mihaila-Amrouche, L; Bouvet, A

    2004-10-01

    The need to rapidly identify streptococci responsible for acute infectious diseases has led to the development of agglutination techniques that are able to identify streptococcal group antigens (A, B, C, D, F, and G) directly from primoculture colonies on blood agar. The Prolex agglutination tests (Pro-Lab Diagnostics, Richmond Hill, Ontario, Canada), distributed in France by i2a, have been used for the determination of group antigens of 166 isolates of streptococci and enterococci previously identified in the National Reference Center for Streptococci. The results obtained with the Prolex reagents have permitted to correctly identify all pyogenic beta-hemolytic streptococci (23 Streptococcus pyogenes, 21 Streptococcus agalactiae, 33 Streptococcus dysgalactiae subsp. equisimilis including 6 group C and 27 group G, and 5 Streptococcus porcinus including 4 group B). Four differences between unexpected agglutinations (A or F) and species identifications have been obtained. These differences were observed for four non-hemolytic isolates of Streptococcus mutans, Streptococcus gordonii, Streptococcus infantarius, and Streptococcus suis. The anti-D reagent has been of value as a marker for isolates of enterococci. Thus, these results confirm the abilities of these agglutination tests for the grouping of beta-hemolytic streptococci. Moreover, the use of Prolex has the advantage to be rapid because of the non-enzymatic but chemical extraction of streptococcal antigens.

  20. Taxonomic Notes on the Abyssal Agglutinated Benthic Foraminifera of the HEBBLE (High Energy Benthic Boundary Layer Experiment) Area (Lower Nova Scotian Continental Rise).

    DTIC Science & Technology

    1983-09-01

    Gulf of Mexico . Marine Sciences International, Woods Hole, Ma. Resig, J.M., 1981 Biogeography of benthic foraminifera of the northern Nazca plate and...HD-A133 743 TAXONOMIC NOTES ON THE ABYSSAL AGGLUTINATED BENTHIC t/i FORAMINIFERA OF-THE H..(U) WOODS HOLE OCEANOGRAPHIC INSTITUTION MRN M A KAMINSKI...Notes On The Abyssal Agglutinated Benthic Foraminifera September 1983 Of The HEBBLE Area (Lower Nova Scotian Continental Rise) 7. A41*heeW L Pinforv Mg

  1. Changes in chemical permeation of disposable latex, nitrile, and vinyl gloves exposed to simulated movement.

    PubMed

    Phalen, Robert N; Le, Thi; Wong, Weng Kee

    2014-01-01

    Glove movement can affect chemical permeation of organic compounds through polymer glove products. However, conflicting reports make it difficult to compare the effects of movement on chemical permeation through commonly available glove types. The aim of this study was to evaluate the effect of movement on chemical permeation of an organic solvent through disposable latex, nitrile, and vinyl gloves. Simulated whole-glove permeation testing was conducted using ethyl alcohol and a previously designed permeation test system. With exposure to movement, a significant decrease (p ≤ 0.001) in breakthrough time (BT) was observed for the latex (-23%) and nitrile gloves (-31%). With exposure to movement, only the nitrile glove exhibited a significant increase (p ≤ 0.001) in steady-state permeation rate (+47%) and cumulative permeation at 30 min (+111%). Even though the nitrile glove provided optimum chemical resistance against ethyl alcohol, it was most affected by movement. With exposure to movement, the latex glove was an equivalent option for overall worker protection, because it was less affected by movement and the permeation rate was lower than that of the nitrile glove. In contrast, the vinyl glove was the least affected by movement, but did not provide adequate chemical resistance to ethyl alcohol in comparison with the nitrile and latex gloves. Glove selection should take movement and polymer type into account. Some glove polymer types are less affected by movement, most notably the latex glove in this test. With nitrile gloves, at least a factor of three should be used when attempting to assign a protection factor when repetitive hand motions are anticipated. Ultimately, the latex gloves outperformed nitrile and vinyl in these tests, which evaluated the effect of movement on chemical permeation. Future research should aim to resolve some of the observed discrepancies in test results with latex and vinyl gloves.

  2. Comparison of agglutinating and neutralizing antibodies to serovar hardjo in sows immunized with two commercial whole culture polivalent anti-leptospira bacterins

    PubMed Central

    Soto, Francisco Rafael Martins; Pinheiro, Sônia Regina; Morais, Zenaide Maria; Gonçales, Amane Paldês; de Azevedo, Sérgio Santos; Bernardi, Fernanda; Camargo, Sebastião Rodrigues; Vasconcellos, Silvio Arruda

    2008-01-01

    It was performed the comparison of the intensity and duration of agglutinating and neutralizing antibodies to serovar Hardjo in swines vaccinated with two commercial anti-leptospira bacterins. Sows no reactive to 24 Leptospira sp serovars in the microscopic agglutination test (MAT) were divided in three groups: Group A (n=08): received two vaccine A doses with 30 days interval, Group B (n=08) two vaccine B doses with 30 days interval and Group C (n=08): control no vaccinated against leptospirosis.Blood samples were collected each 30 days during six months following the first vaccination. The sera were tested by MAT and growth inhibition test (GIT) to serovar Hardjo in order to evaluate respectively agglutinating and neutralizing antibodies. It was found that neutralizing antibodies persisted for a longer time than the agglutinating ones and that the absence of agglutinating antibodies does not means in the absence of the neutralizing. The peaks of agglutinating antibodies was obtained at least 30 days earlier than that produced by neutralizing. The duration of both kinds of antibodies measured differed between the two bacterines tested. The period for inducing neutralizing antibodies against serovar Hardjo indicated that gilts must be immunized with two doses of whole culture anti-leptospira bacterines applied 30 days each other at least 90 days before the first mating. For the maintenance of hight levels of neutralizing antibodies the revaccinations must be performed every six months after the first vaccination. PMID:24031250

  3. A critical review of published methods for analysis of red cell antigen-antibody reactions by flow cytometry, and approaches for resolving problems with red cell agglutination.

    PubMed

    Arndt, Patricia A; Garratty, George

    2010-07-01

    Flow cytometry operators often apply familiar white blood cell (WBC) methods when studying red blood cell (RBC) antigens and antibodies. Some WBC methods are not appropriate for RBCs, as the analysis of RBCs requires special considerations, for example, avoidance of agglutination. One hundred seventy-six published articles from 88 groups studying RBC interactions were reviewed. Three fourths of groups used at least one unnecessary WBC procedure for RBCs, and about one fourth did not use any method to prevent/disperse RBC agglutination. Flow cytometric studies were performed to determine the effect of RBC agglutination on results and compare different methods of preventing and/or dispersing agglutination. The presence of RBC agglutinates have been shown to be affected by the type of pipette tip used for mixing RBC suspensions, the number of antigen sites/RBC, the type and concentration of primary antibody, and the type of secondary antibody. For quantitation methods, for example, fetal maternal hemorrhage, the presence of agglutinates have been shown to adversely affect results (fewer fetal D+ RBCs detected).

  4. Ciprofloxacin Release Using Natural Rubber Latex Membranes as Carrier

    PubMed Central

    Dias Murbach, Heitor; Azevedo Borges, Felipe; Romeiro Miranda, Matheus Carlos; Lopes, Rute; Roberto de Barros, Natan; Guedes Mazalli, Alexandre Vinicius; Gonçalves da Silva, Rosângela; Ferreira Cinman, José Luiz; de Camargo Drago, Bruno; Donizetti Herculano, Rondinelli

    2014-01-01

    Natural rubber latex (NRL) from Hevea brasiliensis is easily manipulated, low cost, is of can stimulate natural angiogenesis and cellular adhesion, is a biocompatible, material and presents high mechanical resistance. Ciprofloxacin (CIP) is a synthetic antibiotic (fluoroquinolone) used in the treatment of infection at external fixation screws sites and remote infections, and this use is increasingly frequent in medical practice. The aim of this study was to develop a novel sustained delivery system for CIP based on NRL membranes and to study its delivery system behavior. CIP was found to be adsorbed on the NRL membrane, according to results of energy dispersive X-ray spectroscopy. Results show that the membrane can release CIP for up to 59.08% in 312 hours and the mechanism is due to super case II (non-Fickian). The kinetics of the drug release could be fitted with double exponential function X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy shows some interaction by hydrogen bound, which influences its mechanical behavior. PMID:25587278

  5. Cytotoxicity of fig fruit latex against human cancer cells.

    PubMed

    Wang, Jing; Wang, Xiujie; Jiang, Shu; Lin, Ping; Zhang, Jie; Lu, Yanrong; Wang, Qi; Xiong, Zhujuan; Wu, Yaying; Ren, Jingjing; Yang, Hongliang

    2008-03-01

    Fig fruit latex (FFL) contains significant amounts of polyphenolic compounds and can serve as a source of antioxidants after human consumption. The purpose of this study is to confirm anticancer activity of FFL against human cancer cells and to further elucidate its mechanism of activity. Human glioblastoma, hepatocellular carcinoma, and normal liver cells were used for in vitro tests of FFL effects. Those tests included cytotoxicity, colony formation inhibition, Brdu incorporation, acridine orange/ethidium bromide (AO/EB) staining for apoptotic cells, cell cycle distribution through flow cytometry (FCM), and ADP-ribosyltransferase (NAD+; poly(ADP-ribose) polymerase)-like 1 (ADPERL1) mRNA expression through RT-PCR in response to FFL treatment. After FFL treatment, the proliferation, colony formation, and Brdu labeling indices of cancer cells decreased (P<0.05), while the AO/EB stained apoptotic cells increased (P<0.05). By FCM analysis, an increase of G(0)/G(1) phase cell population and decrease of S and G(2)/M phase cells were observed (P<0.01), while both ADPRTL1 mRNA expression and apoptotic indices increased (P<0.01). The findings in these studies suggested that FFL exhibited potent cytotoxicity in some human cancer cells with little effect in normal cells at certain concentration. The mechanism for such effects might be associated with the inhibition of DNA synthesis, induction of apoptosis, and cell cycle arrest of cancer cells.

  6. Fully mechanized latex immunoassay for serum lipoprotein(a).

    PubMed

    Abe, A; Yoshimura, Y; Sekine, T; Maeda, S; Yamashita, S; Noma, A

    1994-03-01

    We have developed a fully automated system to quantify lipoprotein(a) (Lp(a)) in human serum, based on the latex-enhanced turbidimetric immunoassay by application of the Immuno Chemistry Analyzer 501X. This assay was carried out with undiluted serum and was able to detect at Lp(a) levels higher than 4.0 mg/l. When judged to be out of range of the calibration (> 600 mg/l), the sample was automatically re-tested after automatic 10-fold dilution. Within-run C.V.s ranged from 1.9 to 2.1% and between-run C.V.s from 2.7 to 3.9%. Results by the present method were in good agreement with those by the in-house ELISA (r = 0.978) and the commercial ELISA (r = 0.990). The distribution of Lp(a) levels in sera from 508 healthy donors was highly skewed; the mean and median were 158 mg/l and 105 mg/l, respectively.

  7. Aggregation kinetics of latex microspheres in alcohol-water media.

    PubMed

    Odriozola, G; Schmitt, A; Callejas-Fernández, J; Hidalgo-Alvarez, R

    2007-06-15

    We report zeta potential and aggregation kinetics data on colloidal latex particles immersed in water-alcohol media. Zeta potential values show absolute maxima for volume fractions of alcohol of 0.10 and 0.05 for ethanol and 1-propanol, respectively. For methanol, no maximum of the absolute value of the zeta potential was found. Aggregation kinetics was studied by means of a single-cluster optical sizing equipment and for alcohol volume fractions ranging from 0 to 0.1. The aggregation processes are induced by adding different potassium bromide concentrations to the samples. We expected to find a slowdown of the overall aggregation kinetics for ethanol and 1-propanol, and no significant effect for methanol, as compared with pure water data. That is, we expected the zeta potential to govern the overall aggregation rate. However, we obtained a general enhancement of the aggregation kinetics for methanol and 1-propanol and a general slowdown of the aggregation rate for ethanol. In addition, aggregation data under ethanol show a slower kinetics for large electrolyte concentration than that obtained for intermediate electrolyte concentration. We think that these anomalous behaviors are linked to layering, changes in hydrophobicity of particle surfaces due to alcohol adsorption, complex ion-water-alcohol-surface structuring, and competition between alcohol-surface adsorption and alcohol-alcohol clustering.

  8. Interaction of latex colloids with mineral surfaces and Grimsel granodiorite.

    PubMed

    Filby, A; Plaschke, M; Geckeis, H; Fanghänel, Th

    2008-12-12

    Bentonite clay is considered as possible backfill material for nuclear waste repositories in crystalline rock. The same material may also be a source of clay colloids, which may act as carriers for actinide ions possibly released from the repository. Depending on the geochemical parameters, these colloids may be retained by interaction with mineral surfaces of the host rock. In the present study interaction of carboxylated fluorescent latex colloids, used as a model for bentonite colloids, with natural Grimsel granodiorite and some of its component minerals is studied by fluorescence microscopy and SEM/EDX. The experiments are carried out by varying the pH from 2-10. Strong adsorption is observed at pH values close to or below the points of zero charge (pHpzc) of the mineral surfaces. The influence of Eu(III), used as a chemical homologue for trivalent actinide ions, on colloid adsorption is investigated. Depending on mineral phase and pH, a significant increase of colloid adsorption is observed in the presence of Eu(III).

  9. Latex nanoparticles for multimodal imaging and detection in vivo

    NASA Astrophysics Data System (ADS)

    Cartier, R.; Kaufner, L.; Paulke, B. R.; Wüstneck, R.; Pietschmann, S.; Michel, R.; Bruhn, H.; Pison, U.

    2007-05-01

    The aim of the present work was to develop a multimodal imaging and detection approach to study the behaviour of nanoparticles in animal studies. Highly carboxylated 144 nm-sized latex nanoparticles were labelled with 68Ga for positron emission tomography, 111In for quantitative gamma scintigraphy or Gd3+ for magnetic resonance imaging. Following intravenous injection into rats, precise localization was achieved revealing the tracer in the blood compartment with a time-dependent accumulation in the liver. In addition, rhodamine B was also incorporated to examine specific interactions with blood cells. Flow cytometry and fluorescent microscopy show uptake of nanoparticles by leucocytes and, unexpectedly, thrombocytes, but not erythrocytes. Cellular internalization was an active and selective process. Further incorporation of polyethylene glycol into the nanoparticle corona could prevent uptake by thrombocytes but not macrophages or monocytes. Our data demonstrate the feasibility of a multimodal approach and its usefulness to analyse the fate of nanoparticles at the macroscopic and cellular level. It will facilitate the development of functionalized nanocarrier systems and extend their biomedical applications.

  10. Interaction of latex colloids with mineral surfaces and Grimsel granodiorite

    NASA Astrophysics Data System (ADS)

    Filby, A.; Plaschke, M.; Geckeis, H.; Fanghänel, Th.

    2008-12-01

    Bentonite clay is considered as possible backfill material for nuclear waste repositories in crystalline rock. The same material may also be a source of clay colloids, which may act as carriers for actinide ions possibly released from the repository. Depending on the geochemical parameters, these colloids may be retained by interaction with mineral surfaces of the host rock. In the present study interaction of carboxylated fluorescent latex colloids, used as a model for bentonite colloids, with natural Grimsel granodiorite and some of its component minerals is studied by fluorescence microscopy and SEM/EDX. The experiments are carried out by varying the pH from 2-10. Strong adsorption is observed at pH values close to or below the points of zero charge (pH pzc) of the mineral surfaces. The influence of Eu(III), used as a chemical homologue for trivalent actinide ions, on colloid adsorption is investigated. Depending on mineral phase and pH, a significant increase of colloid adsorption is observed in the presence of Eu(III).

  11. Natural rubber latex coated with calcium phosphate for biomedical application.

    PubMed

    Borges, Felipe Azevedo; Filho, Edson de Almeida; Miranda, Matheus Carlos Romeiro; Dos Santos, Márcio Luiz; Herculano, Rondinelli Donizetti; Guastaldi, Antônio Carlos

    2015-01-01

    Natural rubber latex (NRL) is a flexible biomembrane that possesses angiogenic properties and has recently been used for guided bone regeneration, enhancing healing without fibrous tissue, allergies or rejection. Calcium phosphate (Ca/P) ceramics have chemical, biological, and mechanical properties similar to mineral phase of bone, and ability to bond to the host tissue, although it can disperse from where it is applied. Therefore, to create a composite that could enhance the properties of both materials, NRL biomembranes were coated with Ca/P. NRL biomembranes were soaked in 1.5 times concentrated SBF solution for seven days, avoiding the use of high temperatures. SEM showed that Ca/P has been coated in NRL biomembrane, XRD showed low crystallinity and FTIR showed that is the carbonated type B. Furthermore, hemolysis of erythrocytes, quantified spectrophotometrically using materials (Ca/P, NRL, and NRL + Ca/P) showed no hemolytic effects up to 0.125 mg/mL (compounds and mixtures), indicating no detectable disturbance of the red blood cell membranes. The results show that the biomimetic is an appropriate method to coat NRL with Ca/P without using high temperatures, aiming a new biomembrane to improve guided bone regeneration.

  12. Simulation of Vertical Surfactant Distributions in Drying Latex Films.

    PubMed

    Gromer, A; Thalmann, F; Hébraud, P; Holl, Y

    2017-01-17

    Following our previous contribution ( Gromer, A. et al. Langmuir 2015 , 31 , 10983 - 10994 ) presenting a new simulation tool devoted to particle distributions in drying latex films, this Article describes the prediction of surfactant concentration profiles in the vertical direction during the complete film formation process. The simulation is inspired by cellular automata and equations by Routh and co-workers. It includes effects that were not considered before: surfactant convection by water and surfactant desorption upon particle deformation. It is based on five parameters describing the nature of the polymer/surfactant system and on film formation conditions. In particular, the viscoelastic properties of the polymer were taken into account through the λ̅ parameter introduced by Routh and Russel. Results show the importance of convection by water and the influence of the particular deformation mechanism on the final surfactant distribution. Excesses or depletions can be predicted either on the surface or on the substrate sides, in qualitative agreement with the numerous existing experimental studies. The complex interplay between parameters governing surfactant distributions makes the results unpredictable without the help of such a simulation tool. Therefore, it should be of interest to both industrial and academic scientists.

  13. Latex micro-balloon pumping in centrifugal microfluidic platforms.

    PubMed

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Harun, Sulaiman Wadi; Al-Faqheri, Wisam; Thio, Tzer Hwai Gilbert; Kazemzadeh, Amin; Madou, Marc

    2014-03-07

    Centrifugal microfluidic platforms have emerged as point-of-care diagnostic tools. However, the unidirectional nature of the centrifugal force limits the available space for multi-step processes on a single microfluidic disc. To overcome this limitation, a passive pneumatic pumping method actuated at high rotational speeds has been previously proposed to pump liquid against the centrifugal force. In this paper, a novel micro-balloon pumping method that relies on elastic energy stored in a latex membrane is introduced. It operates at low rotational speeds and pumps a larger volume of liquid towards the centre of the disc. Two different micro-balloon pumping mechanisms have been designed to study the pump performance at a range of rotational frequencies from 0 to 1500 rpm. The behaviour of the micro-balloon pump on the centrifugal microfluidic platforms has been theoretically analysed and compared with the experimental data. The experimental data show that the developed pumping method dramatically decreases the required rotational speed to pump liquid compared to the previously developed pneumatic pumping methods. It also shows that within a range of rotational speed, a desirable volume of liquid can be stored and pumped by adjusting the size of the micro-balloon.

  14. Polyphenol oxidases from latex of Hevea brasiliensis: purification and characterization.

    PubMed

    Wititsuwannakul, Dhirayos; Chareonthiphakorn, Nopphakaew; Pace, Mario; Wititsuwannakul, Rapepun

    2002-09-01

    Polyphenol oxidase (PPO) was isolated from the B-serum obtained after repetitive freeze-thawing of the bottom fraction isolated from ultracentrifuged fresh latex. The B-serum was subjected to acetone precipitation and CM-Sepharose chromatography, affording two PPOs, PPO-I and PPO-II, which, upon SDS-PAGE, were 32 and 34 kDa, respectively. Both PPOs possessed the same pI (9.2), optimum pH (7) and optimum temperature (35-45 degrees C). They are stable up to 60 degrees C and active at broad pH ranges from 4-9. The K(m) values of PPO-I for dopamine, L-dopa and catechol as substrates are 2.08, 8.33 and 9.09 mM, while those for PPO-II are 2.12, 4.76 and 7.14 mM, respectively. Among various PPO inhibitors tested, 4-hexylresorcinol was the most potent. Anionic detergents were among the most effective activators of the enzymes, while cationic and nonionic detergents showed little and no effect on the PPO activities, respectively.

  15. Ciprofloxacin release using natural rubber latex membranes as carrier.

    PubMed

    Dias Murbach, Heitor; Jaques Ogawa, Guilherme; Azevedo Borges, Felipe; Romeiro Miranda, Matheus Carlos; Lopes, Rute; Roberto de Barros, Natan; Guedes Mazalli, Alexandre Vinicius; Gonçalves da Silva, Rosângela; Ferreira Cinman, José Luiz; de Camargo Drago, Bruno; Donizetti Herculano, Rondinelli

    2014-01-01

    Natural rubber latex (NRL) from Hevea brasiliensis is easily manipulated, low cost, is of can stimulate natural angiogenesis and cellular adhesion, is a biocompatible, material and presents high mechanical resistance. Ciprofloxacin (CIP) is a synthetic antibiotic (fluoroquinolone) used in the treatment of infection at external fixation screws sites and remote infections, and this use is increasingly frequent in medical practice. The aim of this study was to develop a novel sustained delivery system for CIP based on NRL membranes and to study its delivery system behavior. CIP was found to be adsorbed on the NRL membrane, according to results of energy dispersive X-ray spectroscopy. Results show that the membrane can release CIP for up to 59.08% in 312 hours and the mechanism is due to super case II (non-Fickian). The kinetics of the drug release could be fitted with double exponential function X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy shows some interaction by hydrogen bound, which influences its mechanical behavior.

  16. Hormonal treatment of the bark of rubber trees (Hevea brasiliensis) increases latex yield through latex dilution in relation with the differential expression of two aquaporin genes.

    PubMed

    Tungngoen, Kessarin; Viboonjun, Unchera; Kongsawadworakul, Panida; Katsuhara, Maki; Julien, Jean-Louis; Sakr, Soulaiman; Chrestin, Hervé; Narangajavana, Jarunya

    2011-02-15

    Natural rubber is synthesized in laticifers in the inner liber of the rubber tree (Hevea brasiliensis). Upon bark tapping, the latex is expelled due to liber turgor pressure. The mature laticifers are devoid of plasmodesmata; therefore a corresponding decrease in the total latex solid content is likely to occur due to water influx inside the laticifers. Auxins and ethylene used as efficient yield stimulants in mature untapped rubber trees, but, bark treatments with abscisic acid (ABA) and salicylic acid (SA) could also induce a transient increase latex yield. We recently reported that there are three aquaporin genes, HbPIP2;1, HbTIP1;1 and HbPIP1;1, that are regulated differentially after ethylene bark treatment. HbPIP2;1 was up-regulated in both the laticifers and the inner liber tissues, whereas HbTIP1;1 was up-regulated in the latex cells, but very markedly down-regulated in the inner liber tissues. Conversely, HbPIP1;1 was down-regulated in both tissues. In the present study, HbPIP2;1 and HbTIP1;1 showed a similar expression in response to auxin, ABA and SA, as seen in ethylene stimulation, while HbPIP1;1 was slightly regulated by auxin, but neither by ABA nor SA. The analysis of the HbPIP1;1 promoter region indicated the presence of only ethylene and auxin responsive elements. In addition, the poor efficiency of this HbPIP1;1 in increasing plasmalemma water conductance was confirmed in Xenopus oocytes. Thus, an increase in latex yield in response to all of these hormones was proposed to be the major function of aquaporins, HbPIP2;1 and HbTIP1;1. This study emphasized that the circulation of water between the laticifers and their surrounding tissues that result in latex dilution, as well as the probable maintenance of the liber tissues turgor pressure, favor the prolongation of latex flow.

  17. Latex-allergic patients sensitized to the major allergen hevein and hevein-like domains of class I chitinases show no increased frequency of latex-associated plant food allergy

    PubMed Central

    Radauer, Christian; Adhami, Farzaneh; Fürtler, Irene; Wagner, Stefan; Allwardt, Dorothee; Scala, Enrico; Ebner, Christof; Hafner, Christine; Hemmer, Wolfgang; Mari, Adriano; Breiteneder, Heimo

    2011-01-01

    Allergies to certain fruits such as banana, avocado, chestnut and kiwi are described in 30–70% of latex-allergic patients. This association is attributed to the cross-reactivity between the major latex allergen hevein and hevein-like domains (HLDs) from fruit class I chitinases. We aimed to assess the extent of cross-reactivity between hevein and HLDs using sera from latex-allergic patients with and without plant food allergy. Hevein and HLDs of latex, banana, and avocado chitinases were expressed in Escherichia coli as fusion proteins with the maltose-binding protein and purified by affinity chromatography. IgE binding to these proteins was studied in sera from 59 latex-allergic patients and 20 banana-allergic patients without latex allergy by ELISA and ELISA inhibition. Additionally, 16,408 allergic patients’ sera were tested for IgE binding to hevein, latex chitinase, and wheat germ agglutinin using an allergen microarray. Hevein-specific IgE was detected in 34/59 (58%) latex-allergic patients’ sera. HLDs of latex, banana, and avocado chitinases were recognized by 21 (36%), 20 (34%), and 9 (15%) sera, respectively. In contrast, only one of 20 banana-allergic patients without latex allergy was sensitized to chitinase HLDs. In most tested latex-allergic patients’ sera, IgE binding to hevein was only partially reduced by preincubation with HLDs. Among hevein-sensitized, latex-allergic patients, the percentage of plant food allergy (15/34 = 44%) was equal to latex-allergic patients without hevein sensitization (11/25 = 44%). In the general allergic population, 230 of 16,408 sera (1.4%) reacted to hevein and/or a hevein-like allergen. Of these, 128 sera showed an isolated sensitization to hevein, whereas only 17 bound to latex chitinase or wheat germ agglutinin without hevein sensitization. In conclusion, the IgE response to HLDs is elicited by hevein as sensitizing allergen in most cases. Despite considerable cross-reactivity between these allergens, no

  18. A rhamnose-binding lectin from sea bass (Dicentrarchus labrax) plasma agglutinates and opsonizes pathogenic bacteria.

    PubMed

    Cammarata, Matteo; Parisi, Maria Giovanna; Benenati, Gigliola; Vasta, Gerardo R; Parrinello, Nicolò

    2014-06-01

    The discovery of rhamnose-binding lectins (RBLs) in teleost fish eggs led to the identification of a novel lectin family characterized by a unique sequence motif and a structural fold, and initially proposed to modulate fertilization. Further studies of the RBL tissue localization and gene organization were also suggestive of role(s) in innate immunity. Here we describe the purification, and biochemical and functional characterization of a novel RBL (DlRBL) from sea bass (Dicentrarchus labrax) serum. The purified DlRBL had electrophoretic mobilities corresponding to 24 kDa and 100 kDa under reducing and non-reducing conditions, respectively, suggesting that in plasma the DlRBL is present as a physiological homotetramer. DlRBL subunit transcripts revealed an open reading frame encoding 212 amino acid residues that included two tandemly-arrayed carbohydrate-recognition domains, and an 18-residue signal sequence at the N-terminus. The deduced size of 24.1 kDa for the mature protein was in good agreement with the subunit size of the isolated lectin. Binding activity of DlRBL for rabbit erythrocytes could be inhibited in the presence of rhamnose or galactose, did not require calcium, and was optimal at around 20°C and within the pH 6.5-8.0 range. DlRBL agglutinated Gram positive and Gram negative bacteria, and exposure of formalin-killed Escherichia coli to DlRBL enhanced their phagocytosis by D. labrax peritoneal macrophages relative to the unexposed controls. Taken together, the results suggest that plasma DlRBL may play a role in immune recognition of microbial pathogens and facilitate their clearance by phagocytosis.

  19. The clinical meaning of positive latex sIgE in patients with food/pollen adverse reactions.

    PubMed

    Nucera, E; Rizzi, A; Buonomo, A; De Pasquale, T; Pecora, V; Colagiovanni, A; Pascolini, L; Ricci, A G; Sferrazza, A; Patriarca, G; Aruanno, A; Schiavino, D

    2012-01-01

    Natural rubber latex allergy (NRL-A) is an international problem of public health. About 50-60% of NRL-A patients may present adverse reactions after ingestion of cross-reacting vegetable foods. This condition, called "Latex-fruit Syndrome", is a matter of research. The aim of our study is to distinguish between clinical/subclinical latex-fruit syndrome and cross-sensitization to latex and food/pollen allergens on the basis of latex recombinant allergens. We studied 51 patients with food hypersensitivity and serological evidence of NRL sensitization. The subjects underwent an accurate allergological evaluation (skin prick test with latex, food and pollen extracts, specific IgE to latex and recombinant allergens, challenge provocation tests). The patients were divided in two groups: group A) 34 patients with clinical and serological latex and fruit/vegetable allergies; group B) 17 patients allergic to fruits/vegetables and/or pollens, with serological, but not clinical NRL-A. All the latex challenge tests resulted positive in group A patients and only two patients of group B presented positive cutaneous challenge tests. Moreover, specific IgE-antibodies were detected to rHev b 5, to rHev b 6.01, to rHev b 6.02 and to rHev b 8 (and other profilins) of group A patients, while in group B we observed a monosensitization to Hev b8, probably linked to a cross-sensitization to pollens and foods. At the present state of knowledge, we need a multi-parametric approach based on a combination of clinical history, diagnostic tests (CRD) and latex challenge tests to make diagnosis of latex-fruit syndrome.

  20. Study of Antibacterial Activity and Bacteriology of Latex from Asclepias syriaca L

    PubMed Central

    McCay, Steven; Mahlberg, Paul

    1973-01-01

    Whole and fractionated latex of Asclepias syriaca was tested for antimicrobial or growth-promoting activity with 16 genera and species of bacteria. Latex and extracted fractions (distilled water, acetic acid, sodium bicarbonate, sulfuric acid, and ethyl ether) possessed no detectable antimicrobial activity. Comparison of growth curves of selected bacteria incubated with serum and rubber fractions, as well as controls, revealed no detectable inhibition of growth, except for a slight inhibitory response to autoclaved serum. Most bacteria were capable of utilizing latex for a substrate as indicated by the increased growth rate in the exponential phase. The stationary phase was entered simultaneously by both the treated cultures and the controls. Various bacteria cultured in a litmus latex mixture yielded populations which ranged from <104 organisms/ml for Lactobacillus casei, Staphylococcus aureus and Micrococcus lysodeikticus to 1.1 × 1010 organisms/ml for Clostridium acetobutylicum. Whole latex, as well as the serum and rubber fractions, support the growth of various bacteria, but under field conditions there is no evidence for systemic infection of this type of cell by bacteria. PMID:4790590

  1. Regenerated cellulose fibers spun-dyed with carbon black/latex composite dispersion.

    PubMed

    Wang, Chunxia; Du, Changsen; Tian, Anli; Fu, Shaohai; Xu, Changhai

    2014-01-30

    A carbon black (CB)/latex composite was prepared by the method of miniemulsion polymerization for use as a colorant for spun dyeing of regenerated cellulose fibers. Analysis of experimental results revealed that the CB/latex composite had a small particle size and a narrow particle size distribution which were important to ensure a stable dispersion being later added to spinning solution. A good stability of the prepared CB/latex composite dispersion in the spinning solution indicated that it was highly possible to use the CB/latex composite as a colorant for spun dyeing of regenerated cellulose fibers. When a 3.5% mass ratio of CB/latex composite to cellulose was used for spun dyeing, the spun-dyed fibers had the highest tensile strength, breaking elongation and color strength. The rubbing and washing color fastnesses of spun-dyed regenerated cellulose fibers could satisfy requirements of most textiles. This study provided a new insight into producing spun-dyed regenerated cellulose with a novel colorant.

  2. Incidence of sensitization, symptoms, and probable occupational rhinoconjunctivitis and asthma in apprentices starting exposure to latex.

    PubMed

    Archambault, S; Malo, J L; Infante-Rivard, C; Ghezzo, H; Gautrin, D

    2001-05-01

    Latex is a well-known sensitizer. Prospective studies in apprentices beginning to be exposed to latex have not been carried out. We wanted to determine the incidence of skin reactivity, cutaneous symptoms, rhinoconjunctivitis (RC) symptoms, respiratory symptoms, probable occupational RC, and asthma in apprentices in dental hygiene. A total of 122 students starting a program in dental hygiene technology were recruited between 1993 and 1995. A questionnaire, skin-prick tests with common aeroallergens and latex, and assessment of spirometry and responsiveness to methacholine were carried out on entry and at follow-up visits at 20 and 32 months after the start of exposure. Of the 110 subjects who participated for at least 1 follow-up visit, skin reactivity to latex developed in 7. Cutaneous symptoms developed in 6 of the 7, RC symptoms developed in 2, and respiratory symptoms developed in 1. Five of the 7 subjects had significant changes in methacholine responsiveness and fulfilled the definition of probable occupational asthma. Sensitized subjects were more likely to be atopic and to have a previous history of asthma and respiratory symptoms on exercise than were nonsensitized subjects. Three subjects at the 20-month assessment and 4 subjects at the 32-month visit showed skin reactivity. The cumulative incidences for skin sensitization, probable occupational RC, and occupational asthma to latex were 6.4%, 1.8%, and 4.5%, respectively.

  3. Preparation and characterization of latex films photo-immobilized with IFN-α.

    PubMed

    Wu, Lifang; Hu, Kaikai; Zhang, Li; Chen, Wuya; Chen, Xiaohui; You, Rong; Yin, Liang; Guan, Yan-Qing

    2016-09-01

    We developed a biomaterial by photo-immobilizing interferon-α (IFN-α) on the surface of latex condom films for the prevention and treatment of cervicitis, cervical cancers and diseases caused by cervical virus. The IFN-α modification by photoactive N-(4-azidobenzoyloxy) succinimide was characterized on a nano-scale by spectroscopy analysis and micro morphology. The anti-bacterial, anti-cancer, and anti-viral effects of the modified bioactive latex films were evaluated by antibacterial susceptibility testing, Gram staining, flow cytometry, immunofluorescence, and Western blotting. Our results showed that the photo-immobilized IFN-α latex films effectively inhibited the growth of both Neisseria gonorrhoeae and human cervical cancer HeLa cells. Moreover, the expression of anti-viral proteins, including P56, MxA, and 2', 5'-OAS, in the human cervical epithelial cell line NC104 was significantly increased by photo-immobilized IFN-α latex films. Taken together, these results suggest that photo-immobilized IFN-α latex films may have therapeutic effects against cervicitis, cervical cancers, and cervical virus.

  4. Vascular permeability, neutrophil migration and edematogenic effects induced by the latex of Cryptostegia grandiflora.

    PubMed

    Albuquerque, Tatiana M; Alencar, Nylane M N; Figueiredo, Jozi G; Figueiredo, Ingrid S T; Teixeira, Cinthia M; Bitencourt, Flávio S; Secco, Daniela D; Araújo, Eliane S; Ana Maria Leão, C A; Ramos, Márcio V

    2009-01-01

    Inflammatory responses have been described as occurring after exposure to some latex materials. In this study pro-inflammatory activity in the latex of Cryptostegia grandiflora was investigated. The soluble proteins of the latex (CgLP) were isolated from the whole latex and evaluated by in vivo assays. CgLP induced strong inflammatory activity mediated by neutrophil migration, enlarging vascular permeability and increasing myeloperoxidase activity locally in rats. CgLP-induced inflammation was observed in peritonitis, paw edema and air push models. In addition, CgLP caused hyperemia in a healing model. The peritonitis effect was lost when CgLP was previously boiled suggesting the involvement of pro-inflammatory proteins. Thioglycollate increased the neutrophil migration induced by CgLP, but not by fMLP. Mast cell depletion provoked by 40/80 compound did not modify the course of inflammation triggered by CgLP, being similar to fMLP, which suggested that neutrophil migration was induced by direct mechanism mediated by macrophages. Neutrophil migration stimulated by CgLP was strongly inhibited by Dexamethasone and to a lesser extent by Thalidomide, indicating the involvement of cytokines in mediating neutrophil infiltration. Celecoxib and Indomethacin were inhibitory suggesting the involvement of prostaglandins. Cimetidine was effective only in the initial phase of edema. PCA 4248 was ineffective. It is concluded that the latex of C. grandiflora is a potent inflammatory fluid, and also that laticifer proteins may be implicated in this process.

  5. Validation of reference genes for quantitative real-time PCR during latex regeneration in rubber tree.

    PubMed

    Long, Xiangyu; He, Bin; Gao, Xinsheng; Qin, Yunxia; Yang, Jianghua; Fang, Yongjun; Qi, Jiyan; Tang, Chaorong

    2015-06-01

    In rubber tree, latex regeneration is one of the decisive factors influencing the rubber yield, although its molecular regulation is not well known. Quantitative real-time PCR (qPCR) is a popular and powerful tool used to understand the molecular mechanisms of latex regeneration. However, the suitable reference genes required for qPCR are not available to investigate the expressions of target genes during latex regeneration. In this study, 20 candidate reference genes were selected and evaluated for their expression stability across the samples during the process of latex regeneration. All reference genes showed a relatively wide range of the threshold cycle values, and their stability was validated by four different algorithms (comparative delta Ct method, Bestkeeper, NormFinder and GeNorm). Three softwares (comparative delta Ct method, NormFinder and GeNorm) exported similar results that identify UBC4, ADF, UBC2a, eIF2 and ADF4 as the top five suitable references, and 18S as the least suitable one. The application of the screened references would improve accuracy and reliability of gene expression analysis in latex regeneration experiments.

  6. Antibacterial and cytotoxic potential of silver nanoparticles synthesized using latex of Calotropis gigantea L.

    PubMed

    Rajkuberan, Chandrasekaran; Sudha, Kannaiah; Sathishkumar, Gnanasekar; Sivaramakrishnan, Sivaperumal

    2015-02-05

    The present study aimed to synthesis silver nanoparticles (AgNPs) in a greener route using aqueous latex extract of Calotropis gigantea L. toward biomedical applications. Initially, synthesis of AgNPs was confirmed through UV-Vis spectroscopy which shows the surface plasmonic resonance peak (SPR) at 420 nm. Fourier transform infrared spectroscopy (FTIR) analysis provides clear evidence that protein fractions present in the latex extract act as reducing and stabilizing bio agents. Energy dispersive X-ray (EDAX) spectroscopy confirms the presence of silver as a major constituent element. X-ray diffractograms displays that the synthesized AgNPs were biphasic crystalline nature. Electron microscopic studies such as Field emission scanning electron microscopic (Fe-SEM) and Transmission electron microscope (TEM) reveals that synthesized AgNPs are spherical in shape with the size range between 5 and 30 nm. Further, crude latex aqueous extract and synthesized AgNPs were evaluated against different bacterial pathogens such as Bacillus cereus, Enterococci sp, Shigella sp, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli. Compared to the crude latex aqueous extract, biosynthesized AgNPs exhibits a remarkable antimicrobial activity. Likewise in vitro anticancer study manifests the cytotoxicity value of synthesized AgNPs against tested HeLa cells. The output of this study clearly suggesting that biosynthesized AgNPs using latex of C. gigantea can be used as promising nanomaterial for therapeutic application in context with nanodrug formulation.

  7. Interaction of a spirooxazine dye with latex and its photochromic efficiency on cellulosic paper.

    PubMed

    Sun, Bo; He, Zhibin; Hou, Qingxi; Liu, Zehua; Cha, Ruitao; Ni, Yonghao

    2013-06-05

    Spirooxazine (SO) is a class of important photochromic dyes for many applications, such as anti-counterfeiting printing, reversible memory photo devices and optical switching elements in molecular electronics. Since these dyes are expensive, improving their coloration efficiency in response to photo stimuli is of practical importance. In this study, a spirooxazine dye, 1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]naphtha[2,1-b][1,4]oxazine], was dispersed into the substrate of a polystyrene acrylic latex emulsion to obtain a stable photochromic dye loaded latex. The photochromic latex was then applied on cellulose paper, and its coloration efficiency was significantly higher than the control (without the latex). Transmission electron microscope (TEM) observation revealed that the spirooxazine dye was well dispersed into the matrix of the latex particles, which functioned as a carrier/dispersant for the photochromic dye. Other results, including color stability, and fatigue resistance, were also discussed.

  8. Comparative analysis of Papaver somniferum genotypes having contrasting latex and alkaloid profiles.

    PubMed

    Chaturvedi, Nidarshana; Singh, Mridula; Shukla, Ashutosh K; Shasany, Ajit K; Shanker, Karuna; Lal, Raj K; Khanuja, Suman P S

    2014-07-01

    Papaver somniferum produces therapeutically useful benzylisoquinoline alkaloids (BIAs) like papaverine, thebaine, codeine, and morphine that accumulate in its capsular latex. Morphine is a potent analgesic but is also abused as a narcotic, which has increased the demand for non-narcotic thebaine that can be converted into various analgesics. To curtail the narcotic menace, many distinct genotypes of the plant have been developed that are deficient in morphine and/or latex. Sujata is one such latex-less low alkaloid-producing variety developed from the alkaloid-rich gum harvest variety Sampada. Its utility for gene prospecting and studying differential gene regulation responsible for its low alkaloid, nutritive seed oil, and latex-less phenotype has been exploited in this study. BIA profiling of Sujata and Sampada capsules at the early and late stages indicated that except for thebaine, Sujata had a depressed alkaloid phenotype as compared to Sampada. Comparative transcript-based analysis of the two genotypes was carried out in the early stage capsule (higher thebaine) using subtractive hybridization and microarray. Interrogation of a P. somniferum array yielded many differentially expressing transcripts. Their homology-based annotation classified them into categories--latex related, oil/lipid related, alkaloid related, cell wall related, and others. These leads will be useful to characterize the highly sought after Sujata phenotype.

  9. Permeability of nitrile rubber, latex, polyurethane, and neoprene gloves to 18 antineoplastic drugs.

    PubMed

    Connor, T H

    1999-12-01

    The permeability of four glove materials to various antineoplastic drugs was studied. Eighteen antineoplastic drugs posing potential health hazards to handlers were prepared at the highest concentrations normally encountered by hospital personnel. Four glove materials-nitrile rubber, latex, polyurethane, and neoprene-were exposed to the drugs for 30, 60, 90, and 120 minutes. Glove thickness was measured with an electronic digital caliper. Random samples of material were selected from the glove fingertips, and triplicate samples were tested for each drug at each interval. For a majority of the drugs, a bacterial mutagenicity assay was used to measure the amount of drug (if any) that permeated the material. High-performance liquid chromatography was used for drugs not tested with the bacterial assay. The nitrile gloves were the thinnest (0.12 mm), and the latex gloves were the thickest (0.18 mm). The four materials were generally impermeable to each drug. One sample of the nitrile gloves appeared to have a defect, allowing >5% of the drug solution to pass through at 30 minutes. One sample each of the latex, polyurethane, and neoprene gloves demonstrated minimal permeability (< or =1%): One latex glove sample was permeated by carmustine, and paclitaxel permeated one sample each of the polyurethane and neoprene materials. Nitrile rubber, latex, polyurethane, and neoprene gloves were impermeable to 18 antineoplastic drugs in most, but not all, cases.

  10. Antibacterial and cytotoxic potential of silver nanoparticles synthesized using latex of Calotropis gigantea L.

    NASA Astrophysics Data System (ADS)

    Rajkuberan, Chandrasekaran; Sudha, Kannaiah; Sathishkumar, Gnanasekar; Sivaramakrishnan, Sivaperumal

    2015-02-01

    The present study aimed to synthesis silver nanoparticles (AgNPs) in a greener route using aqueous latex extract of Calotropis gigantea L. toward biomedical applications. Initially, synthesis of AgNPs was confirmed through UV-Vis spectroscopy which shows the surface plasmonic resonance peak (SPR) at 420 nm. Fourier transform infrared spectroscopy (FTIR) analysis provides clear evidence that protein fractions present in the latex extract act as reducing and stabilizing bio agents. Energy dispersive X-ray (EDAX) spectroscopy confirms the presence of silver as a major constituent element. X-ray diffractograms displays that the synthesized AgNPs were biphasic crystalline nature. Electron microscopic studies such as Field emission scanning electron microscopic (Fe-SEM) and Transmission electron microscope (TEM) reveals that synthesized AgNPs are spherical in shape with the size range between 5 and 30 nm. Further, crude latex aqueous extract and synthesized AgNPs were evaluated against different bacterial pathogens such as Bacillus cereus, Enterococci sp, Shigella sp, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli. Compared to the crude latex aqueous extract, biosynthesized AgNPs exhibits a remarkable antimicrobial activity. Likewise invitro anticancer study manifests the cytotoxicity value of synthesized AgNPs against tested HeLa cells. The output of this study clearly suggesting that biosynthesized AgNPs using latex of C. gigantea can be used as promising nanomaterial for therapeutic application in context with nanodrug formulation.

  11. Lake-Atmosphere Turbulent EXchanges (LATEX) field measurement campaign

    NASA Astrophysics Data System (ADS)

    Bou-Zeid, E.; Huwald, H.; Lemmin, U.; Selker, J.; Parlange, M. B.

    2006-12-01

    High resolution measurements of surface fluxes in the atmospheric boundary layer over water surfaces are less common than over land. Nevertheless, developing our understanding of air-water interaction is crucial for improving evaporation models, developing and testing surface parameterizations in meso-scale and global circulation models, and understanding local atmospheric dynamics over water. The Lake-Atmosphere Turbulent EXchanges (LATEX) field measurement campaign was designed to address these issues. The experiment took place on a platform in Lake Geneva in Switzerland (exposed to a 30 km long wind fetch) over the period extending from August through October of 2006. The primary instrumentation consisted of: 1) a vertical array of four sonic anemometers and four open-path H2O/CO2 analyzers, 2) a Raman scattering fiber- optic temperature profiler having a resolution of 4-mm vertically and 0.01 deg C in temperature (3 meter range: 1 meter above the water surface and 2 meters below), and 3) a lake current profiler. Additional supporting measurements included net radiation, surface temperature, relative humidity, wave height and speed, as well as several point-measurements of air and water temperature. We present results for fluxes of momentum, heat, water vapor, and CO2 and test flux-profiles relations (derived from Monin-Obukhov similarity) that are frequently used to estimate these fluxes. Different formulations for roughness and scalar lengths are tested for different lake surface conditions. Finally, we look at small scale turbulence over the lake by computing the eddy-viscosity, the turbulent Prandtl number, and turbulent Schmidt numbers for water vapor and CO2 at scales comparable to large eddy simulation (LES) grid scales; these results can be used to prescribe model coefficient a priori in LES or to test the performance of various dynamic models in reproducing the correct sub-grid scale fluxes.

  12. Silver nanoparticles delivery system based on natural rubber latex membranes

    NASA Astrophysics Data System (ADS)

    Guidelli, Éder José; Kinoshita, Angela; Ramos, Ana Paula; Baffa, Oswaldo

    2013-04-01

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV-Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane ( 0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.

  13. Latex condom breakage and slippage in a controlled clinical trial.

    PubMed

    Rosenberg, M J; Waugh, M S

    1997-07-01

    Although millions of couples rely on male latex condoms to protect against unintended pregnancy and sexually transmitted infections, their use is limited in part by questions about their performance. Rates of condom breakage and slippage, two measures of performance, vary broadly across studies. This variation in part reflects study variability and limitations, including sample size, reliance on subjects' memory, user populations, and products evaluated. In an effort to define condom performance in a group of monogamous couples typical of those using condoms for contraception, we conducted a clinical trial of a single brand of lubricated condoms (Durex Ramses). A total of 4637 attempts to use the condom were evaluated. Six breaks occurred before intercourse (nonclinical breaks), and 10 condoms broke during intercourse or were only noted to have broken upon withdrawal (clinical breaks), resulting in a nonclinical breakage rate of 0.13% (95% confidence interval, 0.05-0.28%), clinical breakage rate of 0.28% (0.15-0.48%), and a total breakage rate of 0.41% (0.25-0.64%). The rate of complete slippage was 0.63% (0.42-0.90%), and total failure (clinical breaks plus complete slips) was 1.04% (0.76-1.37%). These rates are lower than those in other studies with the exception of one, a prospective investigation in a population of female prostitutes. Results indicate that condoms can, in experienced, motivated populations, provide excellent performance and suggest that their efficacy at preventing pregnancy may equal that of the most reliable forms of contraception. Because this study involved a single condom brand, these results may not be generalizable to other brands.

  14. Transient shear viscosity of weakly aggregating polystyrene latex dispersions

    NASA Astrophysics Data System (ADS)

    de Rooij, R.; Potanin, A. A.; van den Ende, D.; Mellema, J.

    1994-04-01

    The transient behavior of the viscosity (stress growth) of a weakly aggregating polystyrene latex dispersion after a step from a high shear rate to a lower shear rate has been measured and modeled. Single particles cluster together into spherical fractal aggregates. The steady state size of these aggregates is determined by the shear stresses exerted on the latter by the flow field. The restructuring process taking place when going from a starting situation with monodisperse spherical aggregates to larger monodisperse spherical aggregates is described by the capture of primary fractal aggregates by growing aggregates until a new steady state is reached. It is assumed that the aggregation mechanism is diffusion limited. The model is valid if the radii of primary aggregates Rprim are much smaller than the radii of the growing aggregates. Fitting the model to experimental data at two volume fractions and a number of step sizes in shear rate yielded physically reasonable values of Rprim at fractal dimensions 2.1≤df≤2.2. The latter range is in good agreement with the range 2.0≤df≤2.3 obtained from steady shear results. The experimental data have also been fitted to a numerical solution of the diffusion equation for primary aggregates for a cell model with moving boundary, also yielding 2.1≤df≤2.2. The range for df found from both approaches agrees well with the range df≊2.1-2.2 determined from computer simulations on diffusion-limited aggregation including restructuring or thermal breakup after formation of bonds. Thus a simple model has been put forward which may capture the basic features of the aggregating model dispersion on a microstructural level and leads to physically acceptable parameter values.

  15. Industrial-hygiene walk-through survey report of Firestone Synthetic Rubber and Latex Company, Lake Charles, Louisiana

    SciTech Connect

    Fajen, J.M.; Ungers, L.J.

    1986-03-01

    A walk-through survey was conducted at the Firestone Synthetic Rubber and Latex Company, Lake Charles, Louisiana in July, 1985. The purpose of the survey was to obtain information on the 1,3-butadiene polymer manufacturing process and evaluate exposure potential. Bulk samples of vinylpyridine latex, styrene/butadiene rubber, and polybutadiene rubber were analyzed for residual 1,3-butadiene.

  16. Preparation and Characterization of Latex Particles as Potential Physical Shale Stabilizer in Water-Based Drilling Fluids

    PubMed Central

    Liu, Junyi; Qiu, Zhengsong; Huang, Wei'an; Song, Dingding; Bao, Dan

    2014-01-01

    The poly(styrene-methyl methacrylate) latex particles as potential physical shale stabilizer were successfully synthesized with potassium persulfate as an initiator in isopropanol-water medium. The synthesized latex particles were characterized by Fourier transform infrared spectroscopy (FT-IR), particle size distribution measurement (PSD), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). FT-IR and TGA analysis confirmed that the latex particles were prepared by polymerization of styrene and methyl methacrylate and maintained good thermal stability. TEM and PSD analysis indicated that the spherical latex particles possessed unimodal distribution from 80 nm to 345 nm with the D90 value of 276 nm. The factors influencing particle size distribution (PSD) of latex particles were also discussed in detail. The interaction between latex particles and natural shale cores was investigated quantitatively via pore pressure transmission tests. The results indicated that the latex particles as potential physical shale stabilizer could be deformable to bridge and seal the nanopores and microfractures of shale to reduce the shale permeability and prevent pore pressure transmission. What is more, the latex particles as potential physical shale stabilizer work synergistically with chemical shale stabilizer to impart superior shale stability. PMID:25302336

  17. Bacterial community associated with the trunk latex of Hancornia speciosa Gomes (Apocynaceae) grown in the northeast of Brazil.

    PubMed

    Silva, Thais Freitas da; Coelho, Marcia Reed Rodrigues; Vollú, Renata Estebanez; de Vasconcelos Goulart, Fátima Regina; Alviano, Daniela Sales; Alviano, Celuta Sales; Seldin, Lucy

    2011-03-01

    Prevention or cure of different illnesses through the use of plant latex is a worldwide known concept. The antifungal activity of Hancornia speciosa latex has been observed against Candida albicans. However, H. speciosa latex is not a sterile plant exudate and secondary metabolites produced by bacteria could be involved in fungal inhibition. In the present study, the bacterial communities of the latex from three H. speciosa trees were characterized using traditional plating and molecular methods. Twelve strains isolated from the latex samples were clustered into four groups by amplified ribosomal DNA restriction analysis (ARDRA). One representative of each group was sequenced and they were identified as belonging to the genera Bacillus, Klebsiella, Enterobacter and Escherichia. None of the 12 isolates showed antifungal activity against C. albicans. A lack of a microbial origin for the antifungal properties of latex was noted. DGGE profiles generated from each of the three latex samples showed unique patterns. Sequencing of the DGGE bands demonstrated the affiliation with the genera Klebsiella, Pantoea, Enterobacter and Burkholderia. In addition, clone libraries were generated and the phylogenetic distribution of the 50 analyzed clones was similar to that obtained using DGGE. The presence of some potential pathogens should be considered before using H. speciosa latex in folk medicine.

  18. Preparation and characterization of inorganic-organic trilayer core-shell polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles

    NASA Astrophysics Data System (ADS)

    Bai, Ruiqin; Qiu, Teng; Han, Feng; He, Lifan; Li, Xiaoyu

    2012-07-01

    The inorganic-organic trilayer core-shell polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles have been successfully prepared via seeded emulsion polymerization of acrylate monomers and octamethylcyclotetrasiloxane (D4) gradually, using functional polymethacryloxypropylsilsesquioxane (PSQ) latex particles with reactive methacryloxypropyl groups synthesized by the hydrolysis and polycondensation of (3-methacryloxypropyl)trimethoxysilane in the presence of mixed emulsifiers as seeds. The FTIR spectra show that acrylate monomers and D4 are effectively involved in the emulsion copolymerization and formed the polydimethylsiloxane-containing hybrid latex particles. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirm that the resultant hybrid latex particles have evident trilayer core-shell structure and a narrow size distribution. XPS analysis also indicates that polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles have been successfully prepared and PDMS is rich in the surface of the hybrid latex film. Additionally, compared with the hybrid latex film without PDMS, the hybrid latex film containing PDMS shows higher hydrophobicity (water contact angle) and lower water absorption.

  19. Electrochemistry in Colloids and Dispersions. Volume 1. Electroanalytical Methods and Applications, Electrosynthesis and Electrocatalysis, Polymers and Latexes

    DTIC Science & Technology

    1992-02-04

    Volume I ELECTROANALY1ICAL METHODS AND APPLICATIONS ELECTROSYNTHESIS AND ELECTROCATALYSIS POLYMERS AND LATEXES This document hias been approved for...distribution, diffusion, and transport, electrosynthesis and electrocatalysis , polymers and latexes, and colloidal metals and semiconductors. 3 This report... ELECTROCATALYSIS 6. Electrochemical catalysis in surfactant mediaI James F. Rusling, Naifei Hu, Heping Zhang, David Howe, Chang-ling Miaw, and Eric Couture

  20. Preparation and characterization of latex particles as potential physical shale stabilizer in water-based drilling fluids.

    PubMed

    Liu, Junyi; Qiu, Zhengsong; Huang, Wei'an; Song, Dingding; Bao, Dan

    2014-01-01

    The poly(styrene-methyl methacrylate) latex particles as potential physical shale stabilizer were successfully synthesized with potassium persulfate as an initiator in isopropanol-water medium. The synthesized latex particles were characterized by Fourier transform infrared spectroscopy (FT-IR), particle size distribution measurement (PSD), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). FT-IR and TGA analysis confirmed that the latex particles were prepared by polymerization of styrene and methyl methacrylate and maintained good thermal stability. TEM and PSD analysis indicated that the spherical latex particles possessed unimodal distribution from 80 nm to 345 nm with the D90 value of 276 nm. The factors influencing particle size distribution (PSD) of latex particles were also discussed in detail. The interaction between latex particles and natural shale cores was investigated quantitatively via pore pressure transmission tests. The results indicated that the latex particles as potential physical shale stabilizer could be deformable to bridge and seal the nanopores and microfractures of shale to reduce the shale permeability and prevent pore pressure transmission. What is more, the latex particles as potential physical shale stabilizer work synergistically with chemical shale stabilizer to impart superior shale stability.