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D H Martin

Publications and source records attributed to D H Martin.

At least 73 records · Page 4Linked to original sources
PubMed1990

Comparison of different medium bases for the semiquantitative isolation of anaerobes from vaginal secretions.

Two studies were performed to determine the best medium for the isolation of anaerobes from vaginal secretions. In the first, three different medium bases (brucella, Centers for Disease Control [CDC], and Schaedler) were compared semiquantitatively for ability to support the growth of gram-negative anaerobes from vaginal fluid. Media were supplemented with laked sheep blood, kanamycin, and vancomycin. The brucella base agar formulation supported the growth of anaerobic gram-negative bacilli better than either the CDC or Schaedler base agar formulation. In a second study, nonselective brucella and CDC base sheep blood agar were compared for ability to support the growth of anaerobic gram-positive cocci. Anaerobic gram-positive cocci grew in higher concentrations on CDC base agar than on brucella base agar. On the basis of these observations, we recommend that a CDC base sheep blood agar be used for the nonselective plate and a brucella base plate supplemented with laked sheep blood, kanamycin, and vancomycin be used for isolation of gram-negative bacilli in studies of the anaerobic flora of the female genital tract.

Bacteria, Anaerobic↗
PubMed1988

Fine-tuning the fluorescent antibody test for chlamydial infections in pregnancy.

Endocervical specimens from 168 asymptomatic women in the second trimester of pregnancy were screened for Chlamydia trachomatis infection with both standard tissue culture methods and a direct fluorescein-conjugated monoclonal antibody assay (MicroTrak). Based on tissue culture results, the prevalence of Chlamydia trachomatis was 26.2% in this population. Compared with tissue culture, the monoclonal antibody assay's sensitivity, specificity, and positive predictive value varied depending upon how many elementary bodies were used to define a positive test. Specifically, if a cutoff of ten elementary bodies was used (as per the manufacturer's instructions), the sensitivity, specificity, and positive predictive value of this test were 86.3, 98.4, and 95.0%, respectively. At the other extreme, a cutoff of one elementary body produced a more sensitive but less specific test, with parameters of 93.2, 89.5, and 75.9%, respectively. Based on these data and operating characteristic analysis, the cutoff value defining a positive test was appropriately set at two or more elementary bodies, at least for this study population. This resulted in a sensitivity, specificity, and positive predictive value of 93.2, 95.2, and 87.2%, respectively. This monoclonal antibody assay appears to be a reasonable substitute for cell culture for Chlamydia trachomatis. However, because of varying magnitudes and implications of false-positive and false-negative tests, clinicians are urged to determine the appropriate breakpoint for their individual laboratories and patient populations before substituting the direct fluorescent antibody test for tissue culture.

Antibodies, Monoclonal↗
PubMed1987

Sequential appearance of anchorage independence, uncontrolled nuclear division and tumorigenicity in 7,12-dimethylbenz(a)anthracene-exposed rat tracheal epithelial cells.

Epithelial cell lines derived from rat tracheal implants 2 and 9 months after a 4-week exposure to 200 micrograms dimethylbenz(a)anthracene-beeswax pellets, and previously assayed for growth in soft agarose and tumorigenicity, were tested at the same time of subculture for cytochalasin B-induced multinucleation to determine the relationships between anchorage-independent growth, uncontrolled nuclear division, and tumorigenicity. The relationships among the three phenotypic markers could be separated into five distinct groups. Group I cell lines showed no growth in agarose, showed no cytochalasin-induced multinucleation, and formed no tumors in nude mice. Group II cell lines exhibited anchorage independence but were negative for the other markers. Group III cell lines were anchorage independent and exhibited a positive response to cytochalasin B (more than 10% of the cells had three or more nuclei), but were tumor negative. Group IV cell lines were positive for all three markers. Group V cell lines grew in soft agarose, were cytochalasin B negative, but formed tumors only 4 months after the cell inoculations. The 20 cell lines generated 2 months after carcinogen exposure distributed in the groups as follows: Group I, 20%; Group 2, 20%; Group III, 50%; Group IV, 15%; and Group 5, 10%. The 27 cell lines generated 9 months after carcinogen exposure distributed among the groups as: Group I, 4%; Group II, 18%; Group III, 26%; Group IV, 52% and Group V, 0%. The results indicate that: anchorage independence precedes the two other markers of growth autonomy; uncontrolled nuclear division appears as a separate property after anchorage independence and before tumorigenicity; tumorigenicity appears preferably in the cell populations that exhibit anchorage independence and uncontrolled nuclear division; and progression in growth autonomy occurs in the tracheal implants in vivo which can be detected in vitro as an increase in cell lines positive for the three phenotypic markers.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

A DNA probe for detecting Mycoplasma genitalium in clinical specimens.

Despite decades of careful study, the etiologies of all cases of pelvic inflammatory disease (PID) and non-gonococcal urethritis (NGU) have yet to be described. Mycoplasma genitalium is a newly described organism which has been implicated as a cause of both PID and NGU. Because of fastidious growth requirements, prolonged incubation time and frequent overgrowth in clinical specimens by Mycoplasma hominis, non-culture methods need to be developed for its detection. We have cloned M. genitalium DNA by transfection into Escherichia coli using M13 as the vector. Using these segments as templates, we synthesized radiolabelled cDNAs that were tested for specific hybridization with M. genitalium, and clinically isolated genital mycoplasmas presumptively identified as M. hominis, and Ureaplasma urealyticum. A 256 base-pair segment was found to hybridize with M. genitalium with a sensitivity of 10(2) colour-changing units (CCUs). No cross-hybridization was observed with M. hominis, and cross-hybridization was observed only with large concentrations (greater than 10(6) CCUs) of U. urealyticum. Because of our choice of M13 as the vector, which contains the Lac Operon of E. coli, slight hybridization occurred with E. coli as well. This cDNA can be used against clinical specimens to determine the ecologic niche and spectrum of disease caused by M. genitalium.

DNA, Bacterial↗
PubMed1987

Failure of multiple passages to increase chlamydial recovery.

Because of a previous publication indicating that increasing the number of blind passages to five resulted in a marked increase in Chlamydia trachomatis isolation rates, we evaluated a multiple-blind-passage system in vials. Cervical specimens from 119 pregnant women and 82 specimens from other sources were tested for chlamydial infection. The recovery rate for C. trachomatis was not markedly increased after the first blind passage. Thus, we conclude that multiple blind passages are not necessary to maximize the C. trachomatis isolation rate in a vial system.

Chlamydia Infections↗
PubMed1986

Progression-linked properties of specific-lesion cell populations from 7,12-dimethylbenz[a]anthracene-exposed rat tracheal implants.

The purpose of this study was to determine whether there are any relationships between the morphological expressions of the progression of neoplasia in tracheal epithelium in vivo, and the increased in vitro growth autonomy expressed by carcinogen-altered cell populations isolated from the same tracheas. Rat tracheal implants were exposed for 2 weeks or 4 weeks to 200 micrograms 7,12-dimethylbenz[a]anthracene (DMBA)-beeswax pellets. In the first phase of this study reported earlier (1), the numbers of carcinogen-altered cell populations, identified by their lack of need for exogenous pyruvate and insulin for survival in cell culture, were quantitated 2, 6 and 9 months after the start of the exposures. Before generating the cell cultures, lesions on the pieces of pre-exposed tracheal implants were identified by placing them in organ culture for 24 h and collecting the exfoliated cells from the medium for diagnostic cytopathology. Although the pieces of 2-week DMBA-exposed tracheas had not developed any markedly atypical lesions by 9 months, there was a progressive increase in the growth autonomy of the small number of subculturable cell populations (approximately 1/trachea) obtained from this exposure group. This was seen in the decreased time needed in culture to expand the population for testing anchorage-independent growth and tumorigenicity in nude mice. Also, anchorage-independent growth was markedly enhanced from 25 to 80% between 2 and 6 months and then to 100% at 9 months. Tumorigenicity did not show an increase. In the 4-week DMBA-exposed group, 74% of the large number of subculturable cell populations (approximately 5.0/trachea) already showed anchorage-independent growth at 2 months. This percentage increased to 94-100% at 6 and 9 months. A progressive increase in tumorigenic cell populations was also clearly seen. At 2 months, 26% of the cell populations inoculated into nude mice formed tumors. This number increased from 45 to 61% at 6 and 9 months, respectively. The pieces of tracheas taken at 2 months after the start of the 4-week DMBA exposure had no markedly atypical lesions. At 6 months one marked atypia was detected, and at 9 months five markedly atypical lesions and two carcinomas in situ were present. The cell populations derived from the explants harboring these lesions showed a high incidence of growth autonomy, e.g. anchorage-independent growth and tumor formation, indicating a close relationship between these properties and the evolving morphological manifestations of tumor development.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1985

Safety and effectiveness of ticarcillin plus clavulanic acid in the treatment of community-acquired acute pyelonephritis in adult women.

An open study was conducted to evaluate the safety and effectiveness of ticarcillin plus clavulanic acid in the treatment of 18 adult women with community-acquired Escherichia coli acute pyelonephritis. Eleven of the 18 patients had a history of urinary tract infections, primarily acute pyelonephritis. Six patients had blood culture results positive for E. coli in addition to positive urine culture results. Ticarcillin plus clavulanic acid was administered as the 3.2 g formulation to 11 patients and as the 3.1 g formulation to the other seven. The mean duration of treatment was 9.2 days. Five of the 18 (28 percent) patients had clinical and bacteriologic cures; there were 11 (69 percent) relapses or reinfections and two (11 percent) clinical failures. Adverse reactions (all reversible) were reported in 11 (61 percent) patients, the most frequent of which was phlebitis. These results should prompt further investigation into the treatment of acute pyelonephritis with ticarcillin plus clavulanic acid versus other antibiotics.

Acute Disease↗
PubMed1984

Selection of carcinogen-altered rat tracheal epithelial cells preexposed to 7,12-dimethylbenz[a]anthracene by their loss of a need for pyruvate to survive in culture.

Normal rat tracheal epithelial cells require exogenous pyruvate to survive in culture while carcinogen-altered cells do not. The aims of our study were, (i) to utilize this loss of requirement for pyruvate by carcinogen-altered cells as a way of selecting out and quantitating the numbers of altered cell populations induced in tracheas exposed to 200 micrograms 7,12-dimethylbenz[a]-anthracene (DMBA)-beeswax pellets for different lengths of time, (ii) to determine the constancy of these numbers at increasing time intervals after the exposure, (iii) to look for distinctive growth properties in cell populations that may be related to the exposure conditions. Tracheal implants were exposed for 2 weeks, 4 weeks or continuously to the 200 micrograms DMBA. At 2, 6 and 9 months after the start of exposure, the tracheas were cut into pieces and primary cultures established from outgrowths in an enriched Waymouth's medium. After 2 weeks, pyruvate and insulin were removed from the medium for 2 weeks to kill the normal cells and leave the altered, i.e., the selected cell populations (SPC). The pyruvate and insulin were then returned to the medium to stimulate rapid expansion of the SPC. The length of DMBA exposure had a marked effect on the number of SPC induced in the tracheas. There were 1.8 SPC/trachea 2 months after the 2 weeks exposure, while 5.0 and 7.2 SPC were obtained from the 4 weeks and continuously exposed tracheas, respectively, at this time. The numbers of SPC did not increase with time after exposure indicating that the maximal number of initiation sites was fixed. Between 2 and 9 months the number of subculturable SPC increased from 67 to 88% in the 2 week exposed group, while 93-100% of the SPC were subculturable after the longer DMBA exposures. Only the SPC from the 2 week DMBA--2 month group were distinguished by smaller numbers of cells surviving the selection medium and by a slower average growth rate compared to all the other experimental conditions.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1984

Chlamydia trachomatis infections in men with Reiter's syndrome.

Chlamydia trachomatis was isolated from 9 of 19 men with acute, nondiarrheal Reiter's syndrome who had not recently taken antibiotics. None of 8 untreated men with other forms of arthritis were infected with this organism. Chlamydia trachomatis-specific antibody titers and cellular immune responses were positive significantly more often in 35 treated and untreated men with acute, nondiarrheal Reiter's syndrome than in 7 men with diarrhea-associated Reiter's syndrome and 8 men with other forms of arthritis. Mean peak chlamydial antibody titers and mean lymphocyte transformation stimulation indices were significantly higher in C. trachomatis-infected men with Reiter's syndrome than in C. trachomatis-infected men with uncomplicated nongonococcal urethritis. We concluded that C. trachomatis is capable of "triggering" Reiter's syndrome in susceptible men and that an exaggerated immune response to this organism may play a role in the pathogenesis of the disease.

Acute Disease↗
PubMed1983

Depression of the lymphocyte transformation response to microbial antigens and to phytohemagglutinin during pregnancy.

Lymphocyte transformation (LT) responses to Chlamydia trachomatis, to four other microbial antigens, and to phytohemagglutinin (PHA) were studied in 201 women during pregnancy and/or 3-18 wk postpartum. The LT responses to all stimulants tested were significantly depressed during pregnancy when compared with postpartum LT responses. This difference occurred whether LT assays were performed in autologous or pooled heterologous plasma collected from nonpregnant donors. Among women studied in the third trimester and again postpartum, the autologous LT stimulation index (LTSI) rose from 1.7 to 3.4 (P less than 0.001) with C. trachomatis elementary body antigen, from 3.7 to 7.9 (P less than 0.001) with Candida albicans cell wall extract, from 4.5 to 7.8 (P = 0.008) with streptokinase-streptodornase, from 1.7 to 3.0 (P = 0.007) with fluid tetanus toxoid, from 1.7 to 2.8 (P = 0.046) with mumps virus skin test antigen, from 35.5 to 87.0 (P less than 0.001) with PHA (2 micrograms/ml), and from 107.2 to 181.9 (P = 0.007) with PHA (10 micrograms/ml). LT responses to C. trachomatis were compared in 52 pregnant women and 58 nonpregnant women; all the women had C. trachomatis isolated at the time of LT assay. Using either plasma supplement, the mean LTSI with C. trachomatis antigen was significantly higher in nonpregnant women than in pregnant women, regardless of trimester (P less than 0.001). Among 12 women who were serially tested and remained culture positive for C. trachomatis throughout pregnancy and the postpartum period, the mean autologous LTSI rose from 1.9 in the third trimester to 7.8 postpartum (P = 0.0004). These data are the first to show that the immune response to an ongoing bacterial infection is depressed during pregnancy and to definitively document the depressed LT responses during human pregnancy.

Antigens, Bacterial↗
PubMed1982

Prematurity and perinatal mortality in pregnancies complicated by maternal Chlamydia trachomatis infections.

In a prospective study of morbidity associated with Chlamydia trachomatis infections during pregnancy, we isolated C trachomatis from the endocervix of 18 (6.7%) of 268 women examined before 19 weeks' gestation. Infected women were significantly younger than noninfected women, and significantly more often unmarried, supported by public assistance, and pregnant for the first time. Among women followed up from 19 weeks' gestation until delivery, the mean duration of gestation was significantly shorter for those with antepartum chlamydial infection. Stillbirth or neonatal death occurred in six (33%) of the 18 pregnancies of infected women compared with eight (3.4%) of the 238 pregnancies of noninfected women followed up from the 19th week of gestation through delivery. Stillbirth or neonatal death occurred ten times more often among Chlamydia-infected women than among uninfected controls matched for age, marital status, socioeconomic status, pregnancy order, and race.

Adolescent↗
PubMed1982

Epidemiological significance of Venezuelan equine encephalomyelitis virus in vitro markers.

One hundred and fifty-eight strains of Venezuelan equine encephalomyelitis virus were typed antigenically and classified epidemiologically as either epizootic or enzootic. Plaque sizes for 148 of these strains were determined, and the pH requirements for hemagglutination (HA) of goose erythrocytes of 131 were studied. Only antigenic variant group IABC strains could be classified epidemiologically as epizootic. In vitro these strains were characterized by the formation of small plaques in Vero cells and a relatively narrow pH range for optimum HA reactivity. Experimental studies in horses confirmed the fact that only IABC strains have epizootic potential. We concluded that plaque size in Vero cell monolayers would be a useful method of screening VEE viruses for equine virulent strains. Indirect evidence suggested that small plaques resulted from sensitivity to an anionic substance present in the agar overlay medium.

Animals↗