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T Mangan

Publications and source records attributed to T Mangan.

4 recordsLinked to original sources
PubMed1996

Analytical performance of an immunologic-based periodontal bacterial test for simultaneous detection and differentiation of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia.

The analytical performance of a membrane-based immunoassay for the simultaneous detection and differentiation of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia (including Prevotella nigrescens) was investigated. Positive reactions were observed for 71 of 71 reference strains and recent oral isolates of A. actinomycetemcomitans, P. gingivalis, and P. intermedia. No cross-reactivity was observed with 39 other common oral and environmental species. The specificity of the test was unaffected by the presence of potential oral interferents including whole blood, white blood cells, mucin, saliva, toothpastes, and oral rinses. A proficiency test by dental professionals using a standardized set of unknown simulated samples yielded a sensitivity of 97% (116/120) and a 100% specificity (240/ 240). An additional group including dental professionals and high school students was shown to be 99% proficient (1385/1397) in distinguishing proper from improper test function when processing control samples with normal test devices and devices with simulated error conditions. Comparisons to a culture standard for 104 subgingival plaque samples collected from 26 adult periodontitis patients yielded > 98% specificity for each of the test bacteria. In addition, the detection threshold for the test was determined to be equivalent to 10(4) cultivable test bacteria when compared to the culture standard. The data indicate that this membrane immunoassay is a valid and easy-to-use method for the detection of A. actinomycetemcomitans, P. gingivalis, and P. intermedia in subgingival plaque, at levels above the detection threshold of the test.

Adult↗
PubMed1983

Effects of ultraviolet irradiation on the cell cycle in normal and UV-sensitive cell lines with reference to the nature of the defect in xeroderma pigmentosum variant.

Analysis of the distribution of cells through the phases of the cell cycle by DNA flow cytofluorimetry has been utilized to investigate the effects of ultraviolet (UV) irradiation on cell-cycle progression in normal and UV-sensitive lymphoblastoid cell lines. In time-course studies only slight perturbation of DNA distribution was seen in normal cells, or UV-sensitive familial melanoma (FM) lines in the 48 h following irradiation. Xeroderma pigmentosum (XPA) excision-deficient cells showed a large increase in the proportion of cells in S phase 16-40 h post-irradiation. XP variant (XPV) cells were blocked in G1 and S phases with the complete absence of cells with G2 DNA content 16-28 h after irradiation. By 48 h post-irradiation the DNA distribution of XPA and XPV cells had returned to that of an unirradiated control. When colcemid was added to the cultures immediately after irradiation to prevent mitotic cells dividing and re-entering the cell cycle, progression through the first cycle after irradiation was followed. UV irradiation did not affect the rate of movement of cells out of G1 into S phase in normal, FM or XPA cells. The proportion of cells in S phase was increased in UV-irradiated cultures in these cell types and the number of cells entering the G2 + M compartment was reduced. In UV-irradiated cultures of XPV cells a large proportion of cells was blocked in G1. The rate of accumulation of cells with G2 DNA content was equal to that of the control until 4 h post-irradiation, thereafter falling below the control. Thus XPV cells in S phase at the time of irradiation complete DNA synthesis to reach G2 DNA content. However, cells irradiated in G1 are blocked from entry into S. These results suggest that there is a defect in XPV cells that affects a step prior to the onset of DNA replication.

Cell Cycle↗
PubMed1982

An automated assay of merozoite invasion of erythrocytes using highly synchronized Plasmodium falciparum cultures.

Plasmodium falciparum cultures were synchronized using three lytic treatments with sorbitol. Schizonts from these cultures were used in a rapid, highly sensitive assay of invasion of erythrocytes by merozoites. The parasitaemias in recipient cells after invasion were determined by flow cytofluorimetry after staining with the dye 33258 Hoechst. Invasion of erythrocytes was shown to be reduced by serum from a patient with malaria. The assay is suitable for rapidly screening large numbers of samples, such as monoclonal antibodies.

Animals↗