Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PHA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMed2002

Production of PHA depolymerase A (PhaZ5) from Paucimonas lemoignei in Bacillus subtilis.

Purification of poly(3-hydroxybutyrate) depolymerase (EC 3.1.1.75) from Paucimonas lemoignei is complicated because the bacterium produces several isoenzymes which are difficult to separate from each other. The phaZ5 gene of P. lemoignei encoding extracellular poly(3-hydroxybutyrate) depolymerase A was functionally expressed from the constitutive P43 promoter of pWB980 in a multiple protease-negative mutant of Bacillus subtilis (strain WB800) and secreted to the culture medium. The depolymerase (apparent M(r), 42 kDa; 1.9 mg purified protein per liter culture) was purified from cell-free culture fluid to homogenity by applying only one chromatography step in comparison to at least two necessary steps if poly(3-hydroxybutyrate) depolymerases are purified from P. lemoignei. The recombinant depolymerase lacked any carbohydrate content in contrast to the glycosylated depolymerase of the wild-type. Glycosylation was not essential for activity but enhanced the thermal stability of the enzyme at high temperature. Overexpression of poly(3-hydroxybutyrate) depolymerase in B. subtilis is more efficient than in Escherichia coli.

Bacillus subtilis↗
PubMed1977

Specificity of the inhibitory effect of a grand-multipara serum on MLC reactions and on responses to PHA, PWM and PPD.

An MLC reaction inhibiting serum from a grand-multiparous woman (16 successful pregnancies) is described. The serum producer had the HLA antigen A3;Bw35/Aw19;B18;Dw2 and her husband the antigens A28;Bw35/Aw16;B18;Dw2, and they responded to each other in one-way MLC. The serum had the following characteristics: (1) it inhibited many but not all donors as stimulators in MLC; (2) it usually inhibited these same donors as responders in MLC, but clearly to a lesser degree and with a much lower titre; (3) the inhibition of the stimulating function followed HLA haplotypes in families, and seemed to have HLA-D associated specificity, inhibiting HLA-Dw3 and Dw6 homozygous but not HLA-Dw2 or Dw4 homozygous cells as stimulators; (4) it inhibited more strongly the PWM and PPD responses than the MLC responses of relevant cells; (5) the IgG fraction of the serum had characteristics similar to the non-fractionated serum; (6) the inhibitory effect on MLC reactions and PWM and PPD responses was not absorbable by specific red blood cells or platelets, but could be removed or diminished by specific lymphocytes; (7) the serum was not cytotoxic in the complement-dependent test against non-fractionated mononuclear cells or enriched B-lymphocytes. The findings and the possible biological and clinical significance of human Ia-like antibodies are discussed.

Absorption↗
PubMed1990

Increased proliferation of phytohaemagglutinin (PHA)-stimulated human leucocytes after 8-methoxypsoralen treatment.

The effect of 8-methoxypsoralen on human blood mononuclear cells cultured in darkness has been examined. 8-Methoxypsoralen (1 microgram mL-1, 4.6 microM) added to (phytohaemagglutinin-stimulated cells induced a two-fold increase in the number of mitoses. The number of blastic cells also increased. There was no effect on the formation of micronuclei and there was no chromosomal breakage.

Cell Division↗
PubMed1979

Antibody-dependent and PHA-induced cellular cytotoxicity in rheumatoid arthritis.

One hundred and thirty nine observations of antibody-dependent cell mediated cytotoxicity (ADCC) were made on 77 with rheumatoid arthritis (RA) and 17 healthy controls. There were no differences in ADCC between these 2 groups or within the RA group with regard to disease activity, duration, seropositivity, or drug treatment. Sixty observations of phytohaemagglutinin induced cytotoxicity were made on 22 patients with RA and 10 healthy controls. Again there were no differences in cytotoxicity between the 2 groups.

Adult↗
PubMed1981

Studies on endoreduplication. II. Spontaneous occurrence and cellular kinetics of endoreduplication in PHA-stimulated tonsillar lymphocytes.

Cells with spontaneously endoreduplicated chromosomes were observed in tonsillar lymphocyte cultures from the second to the seventh day of culture, although at a low frequency. Cell cycle kinetics leading to endoreduplication were examined by the 5-bromodeoxyuridine (BrdU)-acridine orange method. The diplochromosomes showed four fluorescent patterns depending on the period during which BrdU was incorporated into the DNA. The kinetic data also revealed two populations among the cells with endoreduplicated chromosomes: one with a shorter (36 or 48 h) and the other with a longer cell cycle time. The existance of the latter population was shown by the fact that cell without differentially stained chromatids were observed many hours after BrdU addition (up to 120 h). This suggests that some cells with endoreduplicated chromosomes originate from cells arrested in G2.

Aneuploidy↗
PubMed1997

Proliferative responses to PHA, anti-CD3 and antigens in patients with lymphoproliferative disease of granular lymphocytes. Mannoproteins of Candida albicans induce proliferation and cytotoxicity.

In this paper we investigated the lymphoproliferative and cytotoxic responses of peripheral blood mononuclear cells (PBMC) of patients affected with lymphoproliferative disease of granular lymphocytes of T cell origin to mitogens and antigens. Most patients with lymphoproliferative disease of granular lymphocytes (LDGL) showed a severely impaired PBMC proliferative capacity in response to phytohemagglutinin, anti-CD3 and tetanus toxoid, an impairment that, in the case of anti-CD3 response, appears to be related to a defect of phosphorylation in response to triggering. In contrast, at least 50% of the patients had normal proliferation in response to a mannoprotein fraction purified from Candida albicans. These data suggest that some CD3+ GL from LDGL patients, that usually respond poorly to proliferative stimuli in vitro, can be triggered to perform these functions by candidal antigens.

Adult↗
PubMed1982

A comparative study of complex mitochondrial DNA in human lymphocytes transformed by Epstein-Barr virus and PHA.

Mitochondrial DNA (mt DNA) molecules, isolated from normal human lymphocytes, lymphocytes stimulated with phytohemagglutinin (72 h) and a cultured Burkitt's lymphoma cell line, were examined by electron microscopy. Only monomeric forms of mt DNA were found in normal human lymphocytes, whereas in the other cell types, catenated forms were also observed. Unicircular complex forms were apparently absent in all the cell types studied, suggesting that these forms are not a common malignant transformation in human cells. No clear correlation between mitochondrial modifications--as detected by stereological analysis--and the presence of catenated forms could be established. It is suggested that other mechanisms rather than replication of mt DNA would appear to be the mechanism responsible for the formation of these forms.

Cell Line↗